Hematology as a diagnostic tool in bovine medicine

Essential oils and capsaicin in the diet of Jersey cows at early lactation and their positive impact on anti-inflammatory, antioxidant and immunological responses

The objective of this work was to determine whether the addition of phytogenic compounds based on essential oils (carvacrol, eugenol, cinnamaldehyde) and resinous pepper oil (capsaicin) to the diet of Jersey cows at the beginning of lactation affects anti-inflammatory, antioxidant and immunomodulatory responses, as well as whether there are effects of EO on blood metabolites, ruminal fermentation, digestibility and milk production and composition. Six primiparous cows (370.00 ± 17 kg body weight (BW); 13.02 kg dry matter intake (DMI); 21 days of lactation and average milk production of 20 ± 2 L per day) were allocated to crossed experimental design (2 × 2) with two experimental periods of 28 days and two treatments. Blood, milk and rumen fluid were collected and, at the end of each period, feed and feces samples were collected to evaluate the apparent digestibility of nutrients. The groups were control (CLT) without supplementation and treated (BEO) with the addition of 150 mg/kg of dry matter of the phytogenic to the concentrated portion of the diet. Cows in the BEO group had lower numbers of leukocytes (P ≤ 0.05) and lymphocytes (P ≤ 0.02), but total protein and globulin levels were higher on days 21 and 28 (P ≤ 0.01). In the BEO group, the levels of immunoglobulin A, immunoglobulin heavy chain and transferrin were higher (P ≤ 0.05). The levels of ceruloplasmin, haptoglobin and C-reactive protein were lower in the BEO group (P ≤ 0.05). Lipid peroxidation levels and protein carbonyl content were lower in the BEO group. The total antioxidant capacity (P ≤ 0.09) and the activity of glutathione S-transferase (P ≤ 0.03) and glutathione peroxidase (P ≤ 0.05) were higher in the BEO group. Cows in the BEO group had lower pH (P ≤ 0.05), acetic acid concentrations (P ≤ 0.01) and higher protozoa counts (P ≤ 0.01). Our results suggest that phytogenic supplementation has positive effects on the health of Jersey cows in early lactation, characterized by immunostimulant, antioxidant and anti-inflammatory effects.

Development of a Specific PCR Assay for Theileria sp. Yokoyama and Assessment of Its Potential to Cause Anemia in Cattle

The clinical implications of Theileria sp. Yokoyama, a recently identified Theileria species in cattle, remain uncertain. The objective of the present study was to evaluate the anemia status in cattle infected with Theileria sp. Yokoyama. Blood samples were collected from 206 cattle across seven Veterinary Ranges in Sri Lanka and analyzed for red blood cell (RBC) indices, including hemoglobin concentration, hematocrit, and RBC counts. Additionally, DNA was extracted from the samples and screened with a newly developed Theileria sp. Yokoyama-specific PCR assay targeting the cytochrome b gene. The PCR results revealed that 60 (29.1%) of the surveyed cattle tested positive for Theileria sp. Yokoyama, with 47 (78.3%) of them being co-infected with other hemopathogen species. Our findings revealed that the cattle breeds, management systems, and tick infestations are potential risk factors for the Theileria sp. Yokoyama infection. Next, we evaluated the anemia status among the surveyed cattle based on the RBC indices. We found that all non-infected cattle were non-anemic. By contrast, anemia was observed in 15 Theileria sp. Yokoyama-infected cattle, including 3 singly infected (anemia rate 3/13, 23.1%) and 12 co-infected cattle (12/47, 25.5%). Our findings suggest that Theileria sp. Yokoyama causes anemia in infected cattle.

Influence of an iron dextran injection in various diseases on hematological blood parameters, including serum ferritin, neonatal dairy calves

BACKGROUND

Feeding milk substitutes with low iron content or whole milk without iron supplementation is considered a major factor in developing iron-deficiency anemia in neonatal dairy calves. Young calves are often supplemented with iron dextran injections on the first day of life to prevent anemia. However, the effects of preventive treatment and the presence of disease on serum iron (Fe) concentrations, serum ferritin levels, and hematological blood parameters during the early neonatal stages have not been examined in detail. Therefore, we examined and evaluated the effects of iron dextran injections and health status on the development of hematocrit (Ht), red blood cells (RBC), hemoglobin concentration (Hb), erythrocyte indices (mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration), Fe, and serum ferritin concentrations in dairy calves within the first 10 days of life. The suitability of serum ferritin as a reliable indicator of anemia in very young calves was evaluated by correlating ferritin concentrations with known laboratory diagnostic parameters of anemia.

RESULTS

Iron supplementation significantly increased Fe levels (P = 0.048) but did not affect serum ferritin levels in neonatal calves. Fe concentrations were significantly lower in diseased than healthy calves (P = 0.0417). Iron supplementation significantly affected the health status, as observed in Ht (Ptreat=0.0057; Phealth=0.0097), RBC (Ptreat=0.0342; Phealth=0.0243), and Hb (Ptreat=0.0170; Phealth=0.0168). Serum ferritin levels did not significantly correlate with Fe levels. Both groups showed marked differences in ferritin levels, with the highest levels measured on day 2. Fe concentrations showed weak negative correlations with Hb and Ht levels on day 3 (ρ=-0.45; P = 0.0034 and ρ=-0.045; P = 0.0032, respectively). RBC count showed strong positive correlations with Hb and Ht levels (ρ = 0.91 and ρ = 0.93; P < 0.001).

CONCLUSION

Iron dextran injections increased Fe concentrations but reduced Ht level, RBC count, and Hb level. The presence of diseases led to a reduction in Fe and higher values of Ht, RBC, and Hb in moderate disease than in severe disease. Due to physiological fluctuations during the first 3 days of life, serum ferritin level seems unuseful for evaluating iron storage before day 4 of life.

Identification of hemolytic anemia in Korean indigenous cattle with a criteria value of reticulocyte count, indirect bilirubin, and L-lactate concentration

Bovine hemolytic anemia has a negative impact on animal welfare and productivity due to its associated clinical symptoms. Hemolysis is generally known to cause reticulocytosis, increased indirect bilirubin, decreased concentration of haptoglobin, and increased lactate dehydrogenase. Additionally, tissue hypoperfusion due to concomitant anemia increases blood lactate concentration. However, few studies have reported the correlation between these indicators and hemolytic anemia in cattle. We expected that alterations in hematological and biochemical parameters could identify cattle with hemolytic anemia. Therefore, in addition to reporting differences in indicators according to hemolytic anemia, this study aimed to derive indicators and set criteria for identification of bovine hemolytic anemia. In cattle with hemolytic anemia, reticulocytosis, increased indirect bilirubin, and increased L-lactate were observed, and the correlation of these indicators with hematocrit (HCT) was confirmed. And since HCT alone has limitations in identifying hemolytic anemia, we suggest additional criteria to identify hemolytic anemia in cattle.

Enzymic Activity, Metabolites, and Hematological Responses in High-Risk Newly Received Calves for "Clinical Health" Reference Intervals

Enzymic activity, metabolites, and hematological responses for reference intervals (RIs) establish ranges of physiological normality, which are useful for diagnosing diseases and physiological alterations. Within the same species, RIs vary according to age, gender, productive and physiological states, and environmental factors including health management and nutrition. RIs have been extensively studied in dairy calves during a critical stage of life (from birth up to first 90 days of age). A critical stage for feedlot calves is their arrival at the feedlot, but no reports determine RIs for different enzymic activity, metabolites, and hematological responses during their initial period at the feedlot. Consequently, a total of 461 high-risk crossbreed beef calves, received on three different dates, were examined upon arrival at the feedlot. Of these, 320 calves (148.3 ± 1.3 kg body weight) whose "clinical health" was evaluated were included in the study. Blood samples were taken upon arrival and on days 14, 28, 42, and 56 to determine the following parameters: enzymic activity, metabolites, electrolytes, white blood cells, platelets, and red blood cells. Enzymic activity, metabolites, and complete blood count were determined by automated analyzers. The freeware Reference Value Advisor Software was used to calculate the non-parametric values of RIs. This study is the first to establish RIs for different enzymic activity, metabolites, and hematological responses in high-risk newly received calves during their initial period at the feedlot. This information will be useful for veterinary clinical practice and research related to the health and welfare of high-risk newly received calves during their initial period at the feedlot.

Novel CRISPR-Cas-powered pen-side test for East Coast fever

Theileria parvacauses East Coast fever (ECF), one of the most important and lethal tick-borne diseases of cattle in sub-Saharan Africa. ECF is a considerable burden to the livestock industry, causing annual losses exceeding US $300 million. Currently, diagnosis of T. parva infections relies mainly on clinical signs, serology, and microscopic identification of parasites in either blood or lymph fluid samples. However, some of these tests might not indicate ongoing infection and they all lack the sensitivity to detect low-level infections. Molecular tests such as nested and quantitative PCR assays offer high sensitivity for detection of T. parva. However, these tests remain highly complex technologies that are impractical to use in resource-limited settings where economic losses due to the disease have the most significant impact. A field-deployable, point-of-care test will be of significant value in the treatment and control of ECF in endemic areas. For this purpose, we have developed a CRISPR-Cas12a-based pen-side tool that can sensitively and specifically detect T. parva based on the p104 gene. We describe a streamlined, field-applicable diagnostic tool comprising a 20 min recombinase polymerase amplification (RPA) reaction followed by a 60 min CRISPR-Cas12a reaction using a FAM/Biotin lateral flow strip readout. We tested two different RPA primer pairs and four different CRISPR-RNAs (crRNAs). The p104-based assay displayed high sensitivity, detecting as low as one infected lymphocyte per three microliters of blood and universally detecting eight different T. parva strains without detecting DNA from other Theileria spp. such as Theileria mutans and Theileria lestoquardi. This work opens the way for a field-applicable diagnostic tool for the sensitive point-of-care early diagnosis of T. parva infections in cattle.

High deoxynivalenol and ergot alkaloid levels in wheat grain: effects on growth performance, carcass traits, rumen fermentation, and blood parameters of feedlot cattle

This study was designed to assess the impacts of a mixture of deoxynivalenol (DON) and ergot alkaloids (EAs) on growth performance, rumen function, blood parameters, and carcass traits of feedlot cattle. Forty steers (450 ± 6.0 kg) were stratified by weight and randomly allocated to 1 of 4 treatments; control-low (CON-L), control-high (CON-H) which contained low or high wheat screenings that lacked mycotoxins at the same level as the mycotoxin-low (MYC-L; 5.0 mg/kg DON, 2.1 mg/kg EA), and mycotoxin-high (MYC-H: 10 mg/kg DON, 4.2 mg/kg EA) diets that included wheat screening with mycotoxins. Steers were housed in individual pens for a 112-day finishing trial. Intake was 24.8% lower (P < 0.001) for MYC steers compared to CON steers. As a result, average daily gains of MYC steers were 42.1% lower (P < 0.001) than CON steers. Gain to feed ratio was also lower (P < 0.001) for MYC steers compared to CON steers. Platelets, alanine aminotransferase, globulins, and blood urea nitrogen were lower (P ≤ 0.008), and lymphocytes, glutathione peroxidase activity (GPx), and interleukin-10 (IL-10) were elevated (P ≤ 0.002) in MYC steers compared to CON steers. Hot carcass weights and backfat thickness were reduced (P < 0.001) in MYC steers, resulting in leaner (P < 0.001) carcasses and higher (P < 0.007) meat yield compared to CON steers. Results suggest that a mixture of DON and EAs negatively impacted health, performance, and carcass traits of feedlot steers, with the majority of this response likely attributable to EAs. However, more research is needed to distinguish the relative contribution of each mycotoxin to the specific responses observed.

Contrast efficacy of novel phase convertible nanodroplets for safe CEUS imaging

Microbubble contrast agents in ultrasound/echocardiography are used to increase the echogenicity of the target tissues, thereby raising the contrast resolution of the resultant image. Recently, the trend has shifted toward the development of phase-convertible nanodroplets as ultrasound contrast agents due to their promising theragnostic potential by switching capability at the active site. Herein, we fabricated pre-PGS- perfluoropentane phase convertible nanodroplets and checked their in vitro and in vivo enhancement and safety profile. For this, we performed experiments on 20 male Wistar rats and 2 dogs. Biochemical assays of both rats and dogs included complete blood profiles, liver function tests, and renal function tests. For rat vitals, monitoring and histopathological analysis were also performed. Converted nanodroplets showed excellent contrast enhancement, better than Sonovue upon in vitro testing, with an enhancement time of up to 14 min. In vivo, experiments showed comparable opacification of the ventricles of both rats and dogs. All biochemical assays remained within the normal range during the study period. The histopathological analysis did not show any signs of drug-induced toxicity, showing the safety of these nanodroplets. Pre-PGS-PFP nanodroplets hold great potential for use in echocardiography and abdominal imaging in both human and veterinary applications after clinical trials.

Impact of Heat Stress on the Balance between Oxidative Markers and the Antioxidant Defence System in the Plasma of Mid-Lactating Modicana Dairy Cows

Animal health is affected during heat stress as a result of impaired immune responses, increased production of reactive oxygen species, and/or a deficiency of antioxidants. This leads to an imbalance between oxidants and antioxidants and results in oxidative stress. Heat stress is usually measured in dairy cattle via the temperature-humidity index (THI). In the present study, we aimed at assessing the influence of incremental THI on the balance between oxidative markers and the antioxidant defence system in the plasma of Modicana cows. Twenty-four multiparous, mid-lactating dairy cows were divided into two groups on the basis of different levels of mean THI reached in the period of the previous week up until the day of blood and milk sampling (April THI1:55, May THI2:68, June THI3:71, July THI4:80). The blood samples were collected to measure reactive oxygen metabolites (ROM) and antioxidant defense markers (ferric reducing ability of plasma (FRAP), paraoxonase (PON), advanced oxidation protein products (AOPP), plasma thiol groups (SHp), as well as lipid-soluble antioxidant pro-vitamin (β-carotene) and vitamins (tocopherol and retinol). Milk characteristics, haematological values, and plasma biochemical metabolites were also evaluated. Results showed a significant increase in ROM (p < 0.05) and a significant decrease in PON (p < 0.05), AOPP (p < 0.05), and β-carotene (p < 0.001). Incremental THI significantly decreased levels of milk fat content, red and white blood cells, plasma glucose, and non-esterified fatty acids, while significantly increasing monocytes and the concentrations of β-hydroxybutyrate and creatinine, but not fructosamine. The results of the study show that heat stress significantly affects reactive oxygen species production and antioxidant parameters. Carotenoid supplementation should be considered to alleviate the impact of these effects.

Genetic background of hematological parameters in Holstein cattle based on genome-wide association and RNA sequencing analyses

Hematological parameters refer to the assessment of changes in the number and distribution of blood cells, including leukocytes (LES), erythrocytes (ERS), and platelets (PLS), which are essential for the early diagnosis of hematological system disorders and other systemic diseases in livestock. In this context, the primary objectives of this study were to investigate the genomic background of 19 hematological parameters in Holstein cattle, focusing on LES, ERS, and PLS blood components. Genetic and phenotypic (co)variances of hematological parameters were calculated based on the average information restricted maximum likelihood method and 1,610 genotyped individuals and 5,499 hematological parameter records from 4,543 cows. Furthermore, we assessed the genetic relationship between these hematological parameters and other economically important traits in dairy cattle breeding programs. We also carried out genome-wide association studies and candidate gene analyses. Blood samples from 21 primiparous cows were used to identify candidate genes further through RNA sequencing (RNA-seq) analyses. Hematological parameters generally exhibited low-to-moderate heritabilities ranging from 0.01 to 0.29, with genetic correlations between them ranging from -0.88 ± 0.09 (between mononuclear cell ratio and lymphocyte cell ratio) to 0.99 ± 0.01 (between white blood cell count and granulocyte cell count). Furthermore, low-to-moderate approximate genetic correlations between hematological parameters with one longevity, 4 fertility, and 5 health traits were observed. One hundred ninety-nine significant SNP located primarily on the Bos taurus autosomes (BTA) BTA4, BTA6, and BTA8 were associated with 16 hematological parameters. Based on the RNA-seq analyses, 6,687 genes were significantly downregulated and 4,119 genes were upregulated when comparing 2 groups of cows with high and low phenotypic values. By integrating genome-wide association studies (GWAS), RNA-seq, and previously published results, the main candidate genes associated with hematological parameters in Holstein cattle were ACRBP, ADAMTS3, CANT1, CCM2L, CNN3, CPLANE1, GPAT3, GRIP2, PLAGL2, RTL6, SOX4, WDFY3, and ZNF614. Hematological parameters are heritable and moderately to highly genetically correlated among themselves. The large number of candidate genes identified based on GWAS and RNA-seq indicate the polygenic nature and complex genetic determinism of hematological parameters in Holstein cattle.

Mechanical properties of clot made from human and bovine whole blood differ significantly

Thromboembolism - that is, clot formation and the subsequent fragmentation of clot - is a leading cause of death worldwide. Clots' mechanical properties are critical determinants of both the embolization process and the pathophysiological consequences thereof. Thus, understanding and quantifying the mechanical properties of clots is important to our ability to treat and prevent thromboembolic disease. However, assessing these properties from in vivo clots is experimentally challenging. Therefore, we and others have turned to studying in vitro clot mimics instead. Unfortunately, there are significant discrepancies in the reported properties of these clot mimics, which have been hypothesized to arise from differences in experimental techniques and blood sources. The goal of our current work is therefore to compare the mechanical behavior of clots made from the two most common sources, human and bovine blood, using the same experimental techniques. To this end, we tested clots under pure shear with and without initial cracks, under cyclic loading, and under stress relaxation. Based on these data, we computed and compared stiffness, strength, work-to-rupture, fracture toughness, relaxation time constants, and prestrain. While clots from both sources behaved qualitatively similarly, they differed quantitatively in almost every metric. We also correlated each mechanical metric to measures of blood composition. Thereby, we traced this inter-species variability in clot mechanics back to significant differences in hematocrit, but not platelet count. Thus, our work suggests that the results of past studies that have used bovine blood to make in vitro mimics - without adjusting blood composition - should be interpreted carefully. Future studies about the mechanical properties of blood clots should focus on human blood alone.

Blood parameters and parasite burden in cattle with chronic fascioliasis

Fascioliasis is a trematodiasis that affects domestic and wild animals as well as humans worldwide. It is a well-recognized disease in livestock, were it produces serious economic losses. Yet in cattle, there is limited information about the burden of liver flukes and its relation to the eggs per gram shed to the environment. There is also lack of knowledge on the effect of parasite load in blood parameters of infected animals, which is important to evaluate the severity and progression of the disease. The objective of this work was to gain insight in these aspects. Cattle from Mendoza province, Argentina, were inspected at a farm and at the abattoir determining the presence or absence of Fasciola hepatica. Each animal was sampled for blood and feces and in the slaughterhouse the livers were inspected. Hematology and blood chemistry parameters were determined, feces were examined for F. hepatica eggs by a quantitative sedimentation technique and livers were thoroughly inspected to determine the number of flukes. Infected cattle presented a mild burden of liver flukes per animal, strongly correlated (r = 0.72) to the number of eggs per gram of feces. The total number of eggs (X̄=35,100) shed per animal to the environment and the type of livestock management techniques in the region exacerbate the role of cattle as efficient reservoirs of this disease. Statistically significant lower red blood cell, lymphocyte and neutrophil counts were observed in infected compared to uninfected animals. All hepatic parameters tested showed highly statistically significant differences (p < 0.001) as well as proteins by cause of rise of globulins in infected cattle. The correlation between the amount of flukes in the liver and the number of eggs per gram of faces indicates coprology as a reliable and cost-effective method to infer parasite burden. The impact of fascioliasis on blood parameters can be of aid for the veterinary practitioner on the assessment of this disease on cattle.

Effects of Brown Seaweed (Ascophyllum nodosum) Supplementation on Enteric Methane Emissions, Metabolic Status and Milk Composition in Peak-Lactating Holstein Cows

The dairy industry contributes significantly to anthropogenic methane emissions, which have an impact on global warming. This study aimed to investigate the effects of a dietary inclusion of brown seaweed Ascophyllum nodosum on enteric methane emissions (EMEs), hematological and blood biochemical profiles, and milk composition in dairy cows. Eighteen Holstein cows were divided into three groups: CON (non-supplemented cows), BS50 (50 mL of 10% A. nodosum), and BS100 (100 mL of 10% A. nodosum). In each cow, measurements of EME, dry matter intake (DMI), and milk yield (MY), as well as blood and milk sampling with respective analyzes, were performed before supplementation (P1), after 15 (P2) days, and after 30 (P3) days of supplementation. A. nodosum reduced (p < 0.05) methane production, methane yield, and methane intensity in both BS50 and BS100, and raised DMI (p < 0.05) only in BS50. Total bilirubin (p < 0.05) was higher in BS50 compared to CON cows in P2, and triacylglycerols were lower (p < 0.05) in BS50 than in CON cows in P3. Higher milk fat content was found in BS50 than in CON cows in P3. C16:0 proportions were higher (p < 0.05) in BS50 and BS100 than in CON cows, while C18:3n-3 was higher (p < 0.05) in BS100 than in BS50 and CON cows in P3. Dietary treatment with A. nodosum reduced EMEs and showed the potential to increase DMI and to improve energy status as well as milk composition in peak-lactating dairy cows.

Hematologic and Serum Biochemical Characteristics of Belgian Blue Cattle

Belgian blue (BB) cattle have an 11-bp deletion in myostatin that causes skeletal muscle hyperplasia and increased muscle mass, leading to a 'double-muscled' phenotype. Preliminary data suggest that this phenotype may be associated with breed-specific hematologic and biochemical values. Therefore, in this study, we sought to compare hematologic and serum biochemical parameters in healthy BB and Holstein Friesian (HF) cows and to propose breed-specific reference intervals for BB cows. Hematologic parameters, total protein, creatinine, creatine kinase (CK) and aspartate transaminase (AST) activities, albumin, and globulins were measured in 183 clinically healthy adult BB and HF cows. There were significant differences between BB and HF cows in 17 of 27 measured parameters. BB cows had significantly higher creatinine concentration and CK and AST activities (p < 0.001). RBCs, hemoglobin, hematocrit (p < 0.001), MCV and lymphocytes (p < 0.05) were also significantly higher in BB cows compared with HF cows. The average N/L ratio was greater than 1 in both breeds. These results suggest that BB and HF cows have significantly different clinically relevant hematologic and serum biochemical values, and, therefore, breed-specific reference intervals should be used.

Efficient leukocytes detection and classification in microscopic blood images using convolutional neural network coupled with a dual attention network

Leukocytes, also called White Blood Cells (WBCs) or leucocytes, are the cells that play a pivotal role in human health and are vital indicators of diseases such as malaria, leukemia, AIDS, and other viral infections. WBCs detection and classification in blood smears offers insights to pathologists, aiding diagnosis across medical conditions. Traditional techniques, including manual counting, detection, classification, and visual inspection of microscopic images by medical professionals, pose challenges due to their labor-intensive nature. However, traditional methods are time consuming and sometimes susceptible to errors. Here, we propose a high-performance convolutional neural network (CNN) coupled with a dual-attention network that efficiently detects and classifies WBCs in microscopic thick smear images. The main aim of this study was to enhance clinical hematology systems and expedite medical diagnostic processes. In the proposed technique, we utilized a deep convolutional generative adversarial network (DCGAN) to overcome the limitations imposed by limited training data and employed a dual attention mechanism to improve accuracy, efficiency, and generalization. The proposed technique achieved overall accuracy rates of 99.83%, 99.35%, and 99.60% for the peripheral blood cell (PBC), leukocyte images for segmentation and classification (LISC), and Raabin-WBC benchmark datasets, respectively. Our proposed approach outperforms state-of-the-art methods in terms of accuracy, highlighting the effectiveness of the strategies employed and their potential to enhance diagnostic capabilities and advance real-world healthcare practices and diagnostic systems.

The Effects of Lentinan on the Hematological and Immune Indices of Dairy Cows

In this study, we investigated the effects of lentinan (LNT) on hematological parameters, immune indices, and metabolite levels in dairy cows. We randomly assigned forty Holstein cows to four treatment groups. The treatments consisted of 0, 5, 10, and 15 g/d of LNT. Compared with the control group, the addition of 10 g/d of LNT decreased the content of ALT and IL-8 but simultaneously increased the content of IL-4 in the cows' serum. Supplementation with 10 g/d of LNT decreased the levels of lymphocyte, RDW, ALT, AST, TC, IL-2, and IL-8, but, concurrently, in-creased the levels of granulocytes and IL-4 in their serum. In addition, supplementation with 15 g/d of LNT decreased the levels of RDW, TC, IL-2, and IL-8, but, at the same time, increased the levels of IL-4 and IgM in their serum. For the metabolomic analysis, cows fed with 0 and 10 g/d of LNT were selected. The results showed that 10 metabolites, including reduced nicotinamide riboside and trehalose, were upregulated in the 10 g/d group. These differential metabolites were enriched in tyrosine metabolism and trehalose degradation and altered two metabolic pathways of ubiquinone and other terpene quinone biosynthesis, as well as starch and sucrose metabolism. These findings provide evidence that LNT could be used to reduce the risk of inflammation in dairy cows.

Anaemia in South American camelids - an overview of clinical and laboratory diagnostics

South American camelids (SACs) play an increasing role in veterinary care in Europe. Many alpacas or llamas presented to veterinarians suffer from anaemia, regularly with a packed cell volume (PCV) below 0.10 l/l, which is a life-threatening condition for the animals. This review article presents clinical and laboratory diagnostic tools for the diagnosis of anaemia in SACs. Clinical identification of anaemic animals can be performed by assessing the FAMACHA© score and the Body Condition Score (BCS), since anaemia in alpacas and llamas correlates with pale mucous membranes and a lowered BCS. Haematological examination of a blood sample can provide a more differentiated diagnosis of anaemia in SACs. A common finding is regenerative anaemia with an increased number of reticulocytes that is often caused by blood loss due to Haemonchus contortus. Changes in a blood smear from an alpaca or llama with regenerative anaemia may include normoblasts (nucleated red blood cells), anisocytosis, poikilocytosis, polychromasia, Howell-Jolly bodies or basophilic stippling. Furthermore, non-regenerative anaemia, often caused by trace element deficiency or cachexia, can also occur.

Haematology and biochemistry in healthy llamas at sea level

In the last years, there has been an increasing interest in llamas, not only as part of a productive system, but mostly as companion animals. Most reports regarding clinical biochemistry and haematology include few llamas and details about their health status are not available. The present study aims to provide haematological and biochemical parameters for llamas of known health status. Twenty-three non-pregnant females and seven males that live in Buenos Aires, Argentina (34°36'S, 58°22'W, at sea level) were studied. Llamas were clinically healthy, in good nutritional status. Animals were kept at grass and were fed hay bale or pellets and water ad libitum. Blood samples were collected by jugular venipuncture in spring. Packed cell volume, leucocyte count, differential white cell count, platelets count, urea, creatinine, total proteins, albumin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, glucose, calcium and phosphate were assessed. No significant differences were observed between males and females, except for platelet count and calcium, which was greater in males (P˂0.01). Values obtained for the different parameters were similar to those previously reported, except for monocytes, alkaline phosphatase, glucose and calcium, that were lower and lymphocytes and platelets count, that were higher in this study. In conclusion, different ambient and methodological conditions might affect some parameters. The parameters hereby presented are representative of llama's population living at sea level in South America.

The genetic architecture of complete blood counts in lactating Holstein dairy cows

Complete blood counts (CBCs) measure the abundance of individual immune cells, red blood cells, and related measures such as platelets in circulating blood. These measures can indicate the health status of an animal; thus, baseline circulating levels in a healthy animal may be related to the productive life, resilience, and production efficiency of cattle. The objective of this study is to determine the heritability of CBC traits and identify genomic regions that are associated with CBC measurements in lactating Holstein dairy cattle. The heritability of CBCs was estimated using a Bayes C0 model. The study population consisted of 388 cows with genotypes at roughly 75,000 markers and 16 different CBC phenotypes taken at one to three time points (n = 33, 131, and 224 for 1, 2, and 3 time points, respectively). Heritabilities ranged from 0.00 ± 0.00 (red cell distribution width) to 0.68 ± 0.06 (lymphocytes). A total of 96 different 1-Mb windows were identified that explained more than 1% of the genetic variance for at least one CBC trait, with 10 windows explaining more than 1% of the genetic variance for two or more traits. Multiple genes in the identified regions have functions related to immune response, cell differentiation, anemia, and disease. Positional candidate genes include RAD52 motif-containing protein 1 (RDM1), which is correlated with the degree of immune infiltration of immune cells, and C-X-C motif chemokine ligand 12 (CXCL12), which is critically involved in neutrophil bone marrow storage and release regulation and enhances neutrophil migration. Since animal health directly impacts feed intake, understanding the genetics of CBCs may be useful in identifying more disease-resilient and feed-efficient dairy cattle. Identification of genes responsible for variation in CBCs will also help identify the variability in how dairy cattle defend against illness and injury.

Hematological reference intervals in newborn dromedary calves in the first week after birth: Age and sex-related variations

The establishment of hematological reference intervals (RIs) is an important tool to assess the health status of animals and to evaluate the impact of diseases at individual and population levels. Nowadays, specific RIs of hematological parameters in newborn dromedary camel calves at birth and during the first week after birth, are lacking. Therefore, RIs for the hematological variables from a complete blood cell count were established in 47 healthy newborn dromedary calves (18 females and 29 males). Blood samples were collected within 2 h after birth (d0), at 24 h (d1), at 3 (d3) and 7 days (d7) after birth, and analyzed within 24 h. The RIs were described based on the 95% confidence interval, and possible differences among mean values due to age (sampling time) and sex were investigated. Statistical analysis showed that age affected all the hematological variables except MCV, MCH, and MCHC, indicating that the adaptational process to the extrauterine life continues for several days after birth; sex affected most of the hematological variables, with higher RBC and PLT count, HGB, PCV, neutrophil population and neutrophil:lymphocyte ratio at d7 in females compared to males. These findings suggest possible sex-based differences in the physiological maturation mechanisms and deserves further investigations. To the best of the authors' knowledge, this is the first report of hematological RIs for newborn dromedary calves at birth up to 7 days of age; the RIs registered in the present study in newborns differ from those reported in adult dromedaries in literature, thus confirming the need for the adoption of separated reference ranges according to age also in the dromedary camel, as previously reported for other species.

Strategies for Bovine Respiratory Disease (BRD) Diagnosis and Prognosis: A Comprehensive Overview

Despite significant advances in vaccination strategies and antibiotic therapy, bovine respiratory disease (BRD) continues to be the leading disease affecting the global cattle industry. The etiology of BRD is complex, often involving multiple microbial agents, which lead to intricate interactions between the host immune system and pathogens during various beef production stages. These interactions present environmental, social, and geographical challenges. Accurate diagnosis is essential for effective disease management. Nevertheless, correct identification of BRD cases remains a daunting challenge for animal health technicians in feedlots. In response to current regulations, there is a growing interest in refining clinical diagnoses of BRD to curb the overuse of antimicrobials. This shift marks a pivotal first step toward establishing a structured diagnostic framework for this disease. This review article provides an update on recent developments and future perspectives in clinical diagnostics and prognostic techniques for BRD, assessing their benefits and limitations. The methods discussed include the evaluation of clinical signs and animal behavior, biomarker analysis, molecular diagnostics, ultrasound imaging, and prognostic modeling. While some techniques show promise as standalone diagnostics, it is likely that a multifaceted approach-leveraging a combination of these methods-will yield the most accurate diagnosis of BRD.

Peripheral blood mononuclear cell mitochondrial enzyme activity in calves is associated with average daily gain, reproductive outcomes, lactation performance, and survival

Mitochondria are central to metabolism and are the primary energy producers for all biosynthesis. The objective of this study was to determine if the mitochondrial enzyme activity of peripheral blood mononuclear cells in heifers was associated with average daily gain, reproductive outcomes, first-lactation milk production, and survival. Twenty-three Holstein and 23 Jersey heifer calves were enrolled, and blood and body weight data were collected at 1, 2, 8, 36, 52, and 110 wk of age. Respiratory and fecal scores were recorded daily for the first 30 d of life. Milk production data were collected from herd management software through first lactation and health events were tracked to the fourth lactation on surviving animals. Mitochondrial isolation and enzyme activities for citrate synthase, complex I, complex IV, and complex V were determined using kits from Abcam. Data were analyzed using GLM and the Logistic procedure of SAS (version 9.4, SAS Institute Inc.). Multivariate regression analyses were conducted to determine if calf mitochondrial enzymatic activity and covariate health indices (fecal and respiratory scores, number of treatments, hematology) were associated with average daily gain (8, 36, 52, and 110 wk), lactation performance (milk yield, fat yield, solids yield, energy-corrected milk, 305-d mature equivalent, and relative value), and reproduction (age at first service, age at first conception, age at first calving, and number of services). For Holsteins and Jerseys, mitochondrial enzyme activities and health indices were correlated with all average daily gain and milk production outcomes (R2 ≥ 0.63 and R2 ≥ 0.45, respectively). Reproduction outcomes were correlated with body weight gain, mitochondrial function, and red blood cell traits for Holsteins and Jerseys (R2 ≥ 0.47 and R2 ≥ 0.55, respectively). Logistic regression analyses were performed to determine if early-life enzymatic activity affected survival outcomes in the herd. Calves below the median for complex V enzyme activity at 1 wk were more likely to be removed from the herd compared with calves above the median by lactation 1, 2, 3, and 4 (odds ratio = 4.7, 7.7, 7.0, and 6.9, respectively). Calves below the median for the difference in hematocrit from 2 to 1 wk were more likely to be removed from the herd compared with calves above the median by lactation 1, 2, 3, and 4 (odds ratio = 13, 10, 5.2, and 4.7, respectively). These findings suggest that predictions of cow performance could be improved by considering the effect of early-life mitochondrial enzymatic activity and health indices.

Latitude and seasons influence the prevalence of Theileria orientalis and affect the hematology of non-grazed dairy cows in Korea

This pilot study aimed to investigate the effects of regional and seasonal variations on the prevalence of Theileria orientalis and the hematological profile of non-grazed dairy cows in Korea. A total of 365 clinically healthy lactating Holstein Friesian cows from 26 dairy farms in 7 provinces that were categorized into northern, central, and southern regions were sampled during the warm period from July to August and the cold period from October to December. The detection of T. orientalis major piroplasm surface protein gene and the hematology non-grazed dairy cows were analyzed using peripheral blood samples. The T. orientalis prevalence was 20.0% (73/365). The prevalence in the southern region was 35.9%, which was significantly higher than that in the central (21.6%) and northern (12.9%) regions (P < 0.05). The prevalence during warm period was higher (43.0%) than that during the cold season (13.5%). The infected cows showed significantly lower erythrocyte counts in the southern region (5.8 ± 0.6 M/µl) and during the warm period (5.8 ± 0.7 M/µl) compared with those in the central and northern regions and during the cold season, which affected the extended RBC parameters, including hematocrit and hemoglobin concentrations. Our findings revealed the prevalence of T. orientalis in Korea, highlighting its high occurrence during warm periods and in certain geographical regions. Climatic factors could contribute to the health and productivity of cattle, as evidenced by the prevalence of T. orientalis and its negative impact on animals.

A single intranasal dose of essential oil spray confers modulation of the nasopharyngeal microbiota and short-term inhibition of Mannheimia in feedlot cattle: a pilot study

Five essential oils (EOs) were previously characterized in vitro and identified as candidate EOs for the development of an intranasal EO spray to mitigate bovine respiratory disease (BRD) pathogens. In the present study, these EOs were evaluated for their potential to (i) reduce BRD pathogens, (ii) modulate nasopharyngeal microbiota, and (iii) influence animal performance, feeding behavior and immune response when a single dose administered intranasally to feedlot cattle. Forty beef steer calves (7-8 months old, Initial body weight = 284 ± 5 kg [SE]) received either an intranasal EO spray (ajowan, thyme, fennel, cinnamon leaf, and citronella) or PBS (Control; n = 20/group) on day 0. Deep nasopharyngeal swabs were collected on days (d) -1, 1, 2, 7, 14, 28, and 42 and processed for 16S rRNA gene sequencing, qPCR, and culturing. Significant effects of EO on community structure (d1), microbial richness and diversity, relative abundance of some dominant phyla (d1, d2, and d14), and the overall interaction network structure of the nasopharyngeal microbiota were detected. The relative abundance of Mannheimia was lower in the EO calves (4.34%) than in Control calves (10.4%) on d2, and M. haemolytica prevalence on d7 as compared to control calves. Feed intake, average daily gain, feeding behavior, and blood cell counts were not affected by EO treatment. Overall, a single intranasal dose of EO spray resulted in moderate modulation of nasopharyngeal microbiota and short-term inhibition of Mannheimia while not influencing animal performance, feeding behavior or immune response. Our study, for the first time, shows the potential use of intranasal EO to mitigate BRD in feedlot cattle.

Bioactive metabolites of Asparagopsis stabilized in canola oil completely suppress methane emissions in beef cattle fed a feedlot diet

Asparagopsis taxiformis (Asparagopsis) has been shown to be highly efficacious at inhibiting the production of methane (CH4) in ruminants. To date, Asparagopsis has been primarily produced as a dietary supplement by freeze-drying to retain the volatile bioactive compound bromoform (CHBr3) in the product. Steeping of Asparagopsis bioactive compounds into a vegetable oil carrier (Asp-Oil) is an alternative method of stabilizing Asparagopsis as a ruminant feed additive. A dose-response experimental design used 3 Asp-Oil-canola oil blends, low, medium, and high Asp-Oil which provided 17, 34, and 51 mg Asparagopsis derived CHBr3/kg dry matter intake (DMI), respectively (in addition to a zero CHBr3 canola oil control), in a tempered-barley based feedlot finisher diet, fed for 59 d to 20 Angus heifers (five replicates per treatment). On four occasions, live weight was measured and CH4 emissions were quantified in respiration chambers, and blood, rumen fluid, and fecal samples were collected. At the end of the experiment, all animals were slaughtered, with carcasses graded, and samples of meat and edible offal collected for testing of consumer sensory qualities and residues of CHBr3, bromide, and iodide. All Asp-Oil treatments reduced CH4 yield (g CH4/kg DMI, P = 0.008) from control levels, with the low, medium, and high Asp-Oil achieving 64%, 98%, and 99% reduction, respectively. Dissolved hydrogen increased linearly with increasing Asp-Oil inclusion, by more than 17-fold in the high Asp-Oil group (P = 0.017). There was no effect of Asp-Oil treatment on rumen temperature, pH, reduction potential, volatile fatty acid and ammonia production, rumen pathology, and histopathology (P > 0.10). There were no differences in animal production and carcass parameters (P > 0.10). There was no detectable CHBr3 in feces or any carcass samples (P > 0.10), and iodide and bromide residues in kidneys were at levels unlikely to lead to consumers exceeding recommended maximum intakes. Overall, Asp-Oil was found to be safe for animals and consumers of meat, and effective at reducing CH4 emissions and yield by up to 99% within the range of inclusion levels tested.

Effects of flavoring additives on feed intake, growth performance, temperament, and markers of immune function for newly received feedlot cattle

Ninety Angus × Hereford steers (259.9 ± 36.18 kg body weight [BW]) were used in a 56-d experiment to assess the effects of flavoring additives on feed intake, and stress and immune response of newly received feedlot cattle. Steers were homogenously distributed by BW into six pens equipped with an individual feed intake monitoring system, and pen was randomly assigned to one of three treatments (15 heads per pen; 30 heads per treatment): a standard feedlot receiving diet (CT), or the same diet with a flavoring additive comprised of either sweeteners (Luctarom Feedlot, SW) or a mix of basic tastes (Luctarom Feedlot Mix, MX) at 1 kg/mT. Pens were equipped with a feed intake monitoring system, while BW, chute behavior, flight speed, blood and saliva samples were collected bi-weekly, and hair samples were collected at 4-wk intervals during the study. Data were analyzed using a mixed-effects model for a pen study using individual animal records with repeated measures. There was a treatment × week interaction (P < 0.01) where meal duration was greater in SW steers than MX and CT on week 3, and then CT on weeks 7 and 8. A trend for treatment × week interaction (P = 0.06) showed that the number of visits per day tended to be greater in SW than MX steers on weeks 4 and 5, and it tended to be greater in SW than MX and CT on week 5. The concentration of IL-6 was greater (P < 0.01) on days 1 and 28 than on day 14. The IgM concentration was greater (P < 0.01) on day 1 compared to days 14, 28, and 56. The concentration of haptoglobin was greater (P < 0.01) on 14 than days 28, 42, and 56, and it was greater (P < 0.01) on day 1 than days 42 and 56. The concentration of serum amyloid A was greater (P < 0.01) on day 1 compared to the rest of sampling days. Fibrinogen concentration was greater (P < 0.01) on day 1 compared to days 14 and 42. The neutrophil-to-lymphocyte ratio was greater (P < 0.01) on days 42 and 56 compared to days 1 and 28, and greater (P < 0.01) on day 14 compared to day 28. Hair and saliva cortisol concentrations were lower (P < 0.01) on day 56 compared to days 1 and 28, respectively. The use of flavoring additives, particularly when based on sweeteners (SW), caused some changes in the feeding pattern of newly received steers. These changes, however, were not consistent over the 56-d feeding period and were not accompanied by a change in growth performance, temperament, biomarkers of stress, inflammation, or immune function.

Effects of dietary supplementation of a blend of Saccharomyces cerevisiae, multiple live probiotic bacteria, and their fermentation products on performance, health, and rumen bacterial community of newly weaned beef steers during a 56-d receiving period

We examined the effects of a blend of Saccharomyces cerevisiae, multiple live probiotic bacteria, and their fermentation products on performance, health, and the ruminal bacterial community of newly weaned beef steers during a 56-d receiving period. Forty newly weaned Angus crossbred steers (221 ± 25.6 kg BW; 180 ± 17 d of age) were stratified by body weight (BW) into four pens (10 steers per pen) such that each pen had a similar average BW at the beginning of the experiment. The pens were randomly assigned to receive a corn silage basal diet (CON; n = 20) or the basal diet supplemented with 9 g/steer/d of PRO feed additive (PRO; n = 20). The PRO additive is a blend of S. cerevisiae and the fermentation products of Enterococcus faecium, Bacillus licheniformis, B. subtilis, Lactobacillus animalis, and Propionibacterium freudenreichii. The DMI and water consumed were monitored using the GrowSafe intake nodes and custom flow meters, respectively. BWs were recorded weekly to calculate average daily gain (ADG). Before morning feeding, 10 mL of blood was taken from each steer on days 0-7, and thereafter weekly for analyses of immune cells, plasma glucose, and NEFAs. On day 56, rumen fluid samples (200 mL each) were collected from all the steers for microbiome analysis. Over the 56-d receiving period, the supplemental PRO had no effects on DMI, water intake, or ADG. However, compared to CON, beef steers fed supplemental PRO tended to have greater ADG (P = 0.08) and BW (P = 0.07) during the first 14 d of the study. There was a treatment × day interaction (P ≤ 0.05) for WBC, neutrophils and monocytes over the 56 d such that beef steers fed supplemental PRO had lower blood concentrations on certain days during the first 7 d after weaning, indicating reduced inflammation or stress response. The results of the rumen microbiome analysis revealed that the relative abundance of complex fiber degrading or obligate proton-reducing bacterial genera such as Bacteroides, Ruminococcus gauvreauii group, Desulfovibrio, Syntrophococcus, and Acetitomaculum were greater (P ≤ 0.05) in beef steers fed supplemental PRO compared to CON. This study demonstrated that dietary supplementation of PRO improved the growth performance, reduced stress or inflammatory response during the initial days after weaning, and altered the ruminal bacterial community toward increased relative abundance of bacterial genera associated with improved rumen function.

Identification, molecular characterization and risk factors of Theileria infection among sheep: a first comprehensive report from North India

The present study was aimed at the identification, molecular characterization, and risk factor assessment of Theileria infection among sheep of Haryana province, north India. A total of 402 blood samples were collected from three different climatic zones of Haryana from March 2020 to September 2021. Light microscopy of blood smears revealed Theileria spp. infection in 47.26% (n = 190), while 60.94% (n = 245) of blood samples were positive using nested PCR. Extensive molecular characterization of Theileria infection using four pairs of species-specific primers indicated the dominance of T. ovis (29.1%) followed by T. lestoquardi (12.69%), T. luwenshuni (5.97%) and T. annulata (1.49%). Mixed infection was detected in 11.69% of cases. Bidirectional sequencing and phylogeny further confirmed the presence of these four Theileria spp. in the investigated area under study. Hematology indicated a significant (p < 0.01) reduction in various haematological indices of animals infected with T. luwenshuni and T. lestoquardi compared to the healthy control group. Risk factors like age, sex, and zone were significantly associated with Theileria infection in sheep. The present investigation depicts the first comprehensive molecular report of ovine Theileria spp., which warrants further study to develop suitable control strategies against these haemoparasitic infections.

Feeding colostrum and transition milk facilitates digestive tract functionality recovery from feed restriction and fasting of dairy calves

The objective of this study was to evaluate the digestive tract recovery and metabolism of feeding either bovine colostrum (BC), transition milk (TM), or milk replacer (MR) after an episode of feed restriction and fasting (FRF) in dairy calves. Thirty-five Holstein male calves (22 ± 4.8 d old) were involved in a 50-d study. After 3 d of feeding 2 L of rehydration solution twice daily and 19 h of fasting (d 1 of study), calves were randomly assigned to one of the 5 feeding treatments (n = 7): calves were offered either pooled BC during 4 (C4) or 10 (C10) days, pooled TM during 4 (TM4) or 10 (TM10) days, or MR for 10 d (CTRL) at the rate of 720 g/d DM content. Then, all calves were fed the same feeding program, gradually decreasing MR from 3 L twice daily to 2 L once daily at 12.5% DM until weaning (d 42), and concentrate feed, water, and straw were offered ad libitum until d 50. Citrulline, Cr-EDTA, β-hydroxybutyrate (BHB), and nonesterified fatty acids (NEFA) in serum and complete blood count (CBC) were determined on d -3, 1, 2, 5, and 11 relative to FRF, except BHB and NEFA at d -3. Volatile fatty acids (VFA), lactoferrin (LTF), IgA, and microbiota (Firmicutes to Bacteroidetes ratio and Fecalis prausnitzii) were analyzed in feces on d 5 and 11 before the morning feeding. Health scores were recorded daily from d -3 to d 14 as well as d 23 and 30. Feed concentrate, MR, and straw intake were recorded daily, and body weight on d -3, 1, 2, 5, and 11 and weekly afterward. Calf performance, intake, serum Cr-EDTA, CBC, fecal LTF concentrations and microbiota parameters were similar among treatments throughout the study. Serum NEFA concentrations were greater in TM4, TM10 and C10 calves compared with the CTRL ones from d 2 to 11, and after the FRF, serum concentrations of BHB were lower in CTRL calves than in the other treatments, and on d 11, serum BHB concentrations in the long treatments (C10 and TM10) remained greater than those in the shorter ones (C4 and TM4) and CTRL. Serum citrulline concentrations were similar on d -3 and 1 in all treatments, but they were greater in C4, C10, TM4, and TM10 on d 2 and 5, and on d 11 they were only greater in C10 and TM10 than in CTRL calves. Fecal IgA concentrations tended to be greater in C10 than in CTRL, TM4, and TM10 calves, and in C4 and TM10 than in CTRL animals. Fecal propionate proportion was lesser in C10 than in CTRL, TM4, and TM10 calves, while butyrate was greater in C4 and C10 than in TM4 and CTRL calves. The proportion of non-normal fecal scores of C10 fed calves was greater than TM4 and TM10 calves. Results showed that TM and BC may help to recover intestinal functionality, provide gut immune protection, and increase liver fatty acid oxidation in calves after a FRF episode.

Effects of isoenergetic supplementation as water use mitigation strategy on water footprint and health of nursing bull calves

Sustainable livestock systems focus on mitigating natural resource use such as water. Dietary management strategies can significantly reduce the water footprint of livestock animals; however, animal health is of concern when animals reduce water intake due to subacute dehydration. To evaluate potential consequences of this nutritional management intervention, a total of 23, 60 ± 3 days old nursing Holstein bull calves, weighing 94.7 ± 12.07 kg, were distributed in a completely randomized design and received one of three diets. Control was a basal diet composed of a non-medicated milk replacer (milk replacer; n = 7), and the additional two diets, were composed of the same non-medicated milk replacer in addition to either lipid [n = 8; milk replacer + menhaden fish oil (3 %)] or soluble carbohydrate [n = 8; milk replacer + corn starch (7%) isoenergetic to fat group] supplements. Animals were offered ad libitum mineral mix and water, as well as 120 g/day of a composite mix of dried microbrewery's spent grains. Data were analyzed as linear and generalized linear mixed models with diet as a fixed effect and animal as random utilizing R studio (R Core Team, 2021, Vienna, Austria; SAS Inst., Cary, NC). Within supplementation groups, lipid supplemented calves had the highest lymphocyte (63.24 vs 57.69 counts/100 lymphocytes; P < 0.033), and lowest neutrophil counts (29.3 vs 35.3 counts/100 lymphocytes; P < 0.047). Supplementation significantly increased total serum protein (P = 0.001) and skin moisture (P < 0.011), with carbohydrate group having the highest skin moisture (5.30 vs 3.99; P < 0.047). Supplementation also decreased fecal fluidity scores (P < 0.001) with no significant change in serum electrolytes (P > 0.256). No significant differences were found amongst treatments for the ingestive behavior (P > 0.338). The carbohydrate-supplemented calves significantly decreased all daily water footprints compared to the control and fat-supplemented groups: blue a 47.55 L decrease, (P < 0.001), green a 265.62 L decrease (P = 0.005), and gray a 55.87 L decrease (P = 0.009) water footprint, as well as total water footprint (369.04 L, P = 0.004). Our results indicate the potential to maintain animal performance while increasing water use efficiency through diet supplementation tailored to mitigate water use, without adverse effects on animal health.

Production of rumen- and gastrointestinal-resistant nanoparticles to deliver lysine to dairy cows

Supplementing diets with rumen-protected lysine is a common strategy to meet the nutritional needs of high-producing dairy cows. This work addressed two separate but crucial issues: the lysine protection degree across the entire digestive tract as well as the production scalability of the proposed delivery systems. This was achieved by evaluating, in vitro or ex vivo, previously developed rumen-resistant lipid nanoparticles regarding their stability in the digestive tract and in the bloodstream of the dairy cow as well as how their production could be scaled-up. Results showed that the developed nanoparticles were able to resist digestion along the digestive tract but were degraded in the blood over 24 h. Thus, releasing their content to be used by the animal. In vitro viability assays were also performed, with the nanoparticles being found not to be inherently toxic when using nanoparticle concentrations up to 1 mg/mL. Results showed that neither the purity of the used lipids nor the production method significantly altered the nanoparticles' properties or their ruminal resistance. Furthermore, the shelf-life of these nanoparticles was assessed, and they were found to retain their properties and remain usable after at least 1 month of storage. Moreover, a pilot-scale production allowed the production of nanoparticles with similar properties to the previous ones made using standard methods. To summarize, the proposed rumen-resistant nanoparticles presented potential as orally ingested lysine delivery systems for dairy cattle supplementation, being capable of a large-scale production using cheaper components while maintaining their properties and without any efficiency loss. It should however be noted that these results were obtained mainly in vitro and further in vivo bioavailability and production experiments are needed before this technology can be confirmed as a viable way of delivering lysine to dairy cows.

Effect of dietary seaweed (Ascophyllum nodosum) supplementation on milk mineral concentrations, transfer efficiency, and hematological parameters in lactating Holstein cows

This study investigated the effect of feeding seaweed (Ascophyllum nodosum) to dairy cows on milk mineral concentrations, feed-to-milk mineral transfer efficiencies, and hematological parameters. Lactating Holstein cows (n = 46) were allocated to 1 of 2 diets (n = 23 each): (1) control (CON; without seaweed) and (2) seaweed (SWD; replacing 330 g/d of dried corn meal in CON with 330 g/d dried A. nodosum). All cows were fed the CON diet for 4 wk before the experiment (adaptation period), and animals were then fed the experimental diets for 9 wk. Samples included sequential 3-wk composite feed samples, a composite milk sample on the last day of each week, and a blood sample at the end of the study. Data were statistically analyzed using a linear mixed effects model with diet, week, and their interaction as fixed factors; cow (nested within diet) as a random factor; and data collected on the last day of the adaptation period as covariates. Feeding SWD increased milk concentrations of Mg (+6.6 mg/kg), P (+56 mg/kg), and I (+1,720 μg/kg). It also reduced transfer efficiency of Ca, Mg, P, K, Mn, and Zn, and increased transfer efficiency of Mo. Feeding SWD marginally reduced milk protein concentrations, whereas there was no effect of SWD feeding on cows' hematological parameters. Feeding A. nodosum increased milk I concentrations, which can be beneficial when feed I concentration is limited or in demographics or populations with increased risk of I deficiency (e.g., female adolescents, pregnant women, nursing mothers). However, care should also be taken when feeding SWD to dairy cows because, in the present study, milk I concentrations were particularly high and could result in I intakes that pose a health risk for children consuming milk.

Effects of weaning strategies on health, hematology, and productivity in Holstein dairy calves

Weaning strategies in dairy calves vary considerably, though the effect on animal health is unclear. This study examined the effects of calf weaning age (6 vs. 8 wk) and pace (abrupt vs. gradual) on performance, blood, and health parameters in dairy calves. The experiment consisted of a 2 × 2 factorial arrangement of treatments, where the factors included weaning age (early vs. late) and weaning pace (abrupt vs. gradual). Holstein calves (n = 72), blocked by sex and birth weight, were randomly assigned to one of 4 treatments (n = 18 per treatment): early-abrupt (EA), early-gradual (EG), late-abrupt (LA), and late-gradual (LG). Milk replacer (24% crude protein, 17% fat; up to 1,200 g/d) was fed twice daily; water, calf starter (18% crude protein), and chopped alfalfa hay were fed ad libitum. Daily intakes of milk replacer, calf starter, and forage were recorded from birth until end of weaning. Body weight, selected health measures, blood hematology, and fecal scores were obtained 1 d preweaning and 1 d postweaning. Calves were orally bolused with a rumen pH logger for the last 3 d of the weaning transition and rumen pH was measured continuously. Data were analyzed with age, pace, age × pace interaction, birthweight, and sex as fixed effects, and starting date as a random effect. Greater age at weaning increased respiration, whereas gradual-weaned calves had lower respiration rate. Heart rate was lower in gradual than in abrupt weaned groups. Fecal score had a marginal increase in late-weaned groups and significantly increased in gradually weaned groups. No difference was detected in body core temperature by age, pace, or interaction. During the weaning transition, average daily gain was lower in LA than EA and gradually weaned groups had an increased average daily gain. Change in grain intake, but not forage intake, was greater in gradually weaned groups. Mean rumen pH marginally increased from EG to LG and from LA to LG. No difference was detected among treatments in red or white blood cell counts, and hemoglobin. Procalcitonin was marginally highest in the LA group, while blood hematocrit increased in abruptly weaned groups. Overall, calf health is affected by both age and pace of weaning, though the health parameters affected by age and pace differ.

Examination of the haematological profile of pregnant Polish Holstein-Friesian black-and-white cattle in the early stage

Introduction

Cattle health and welfare are monitored via the analysis of the haematological profile, and it shows cattle's ability to adapt to changing environmental conditions, pregnancy and lactation; profile changes also indicate reproductive disorders. The literature lacks reports of the examination of the haematological profile in cows up to the 50th day of pregnancy (dop). Therefore, this research examined that in cows up to this pregnancy stage.

Material and Methods

A total of 101 Polish Holstein-Friesian black-and-white cows were divided into groups. The control groups consisted of non-pregnant heifers (group C00) and non-pregnant cows (group C0), and the experimental groups were pregnant heifers (group T1 at dop ≤ 28 and group T2 at dop ≥ 29-dop < 45) and pregnant cows (group T3 at dop ≥ 29-dop ≤ 50). In addition, the T3 group was divided into cows pregnant for up 45 dop and cows between 45 and 50 dop. Blood samples were collected in March and April 2021 from each animal and analysed. A transrectal ultrasound examination was performed to detect and confirm pregnancy.

Results

Statistically significant differences (P ≤ 0.01) between the group of cows at dop < 45 dop and those at dop ≥ 45-dop ≤ 50 dop were noted in granulocyte percentage (GRA%), white and red blood cell counts (WBC/RBC), platelets (PLT), platelet distribution width (PDW), haematocrit (HCT) and lymphocyte percentage (LYM%). No statistically significant differences were found in the mean corpuscular haemoglobin, monocytes (MON), monocyte percentage (MON%), mean platelet volume (MPV), thrombocrit or red blood cell distribution width (RDW). Similar statistically significant differences (P ≤ 0.01) emerged between the groups of heifers in PLT, GRA, RBC, lymphocytes, LYM% and HCT, and no significant differences were found between MPV, MON, MON% or RDW.

Conclusion

Examining the haematological profile in high-yielding cattle is vital in maintaining herd profitability and high reproduction, which depend on the quick diagnosis of disorders facilitated by haematology. This study analysed the haematology profile of dairy cattle at dop ≤ 50 for the first time, indicating changes in lymphocyte levels, which suggests that the animals experienced direct stress during the study.

Evaluation of the effects of the recommended oral dose of diflubenzuron on bovine sperm and oocyte quality using CASA and OPU-IVEP

Introduction

The aim of this study was to evaluate potential effects of diflubenzuron on the production and quality of gametes, and on in vitro embryo production (IVEP) outcomes, in cattle.

Methods

Two experiments were performed, the first to evaluate effects on semen, and the second on cumulus-oocyte complexes (COC) and on IVEP. Nelore (Bos taurus indicus) bulls (n = 14) or heifers (n = 16) were allocated into control (CG) or treatment (DIF) groups. All groups received a mineral mix supplement added (DIF) or not (CG) with diflubenzuron (30 mg/head/day), during 8 weeks. Animals were weighed and blood samples were collected throughout the experimental period. Every other week, bulls were subjected to semen collection and heifers to transvaginal ultrasound-guided follicle aspiration sessions. Semen underwent physical and morphological evaluation, and samples were stored for further computer-assisted sperm analysis. The COC recovered were evaluated according to morphology and those classified as viable were sent to an IVEP laboratory.

Results

Diflubenzuron had no effect (P > 0.05) on average body weight or in any blood hematological or biochemical endpoints, regardless of gender. In experiment 1, there was no difference (P > 0.05) between DIF and CG groups for sperm concentration, morphology, or kinetics. In experiment 2, there was also no effect of diflubenzuron on the number of total, viable, or grade I oocytes, as well as on cleavage or blastocyst rates (P > 0.05).

Discussion

In summary, the oral administration of diflubenzuron, within the recommended dose, has no short-term negative effects on sperm production and quality or on oocyte yield and developmental potential in vitro, in cattle.

Haematological values in cattle reared in humid and subhumid tropics of Mexico

The objective of this study was to determine some factors that influence the haematological values of cattle reared in the humid and subhumid tropics of Mexico. Whole blood samples were taken from 1355 crossbred cattle in the years 2017 to 2019. Haematocrit (HTC, %), total plasma protein (TPP, g/dL) and peripheral eosinophils count (PEOS, × 10³/µL) were determined manually, and the main haematological variables were recorded with an automatic analyser. The statistical analysis considered as classification variables age, sex, season (cold, dry and rainy), year (2017, 2018 and 2019) and origin of the cattle. The mean of the haematological parameters was determined along with the confidence limits (CL) of the different categories of animals according to age. Calves younger than 1-year-old presented higher levels of HTC, red blood cell count (RBC), haemoglobin (HGB), red blood cell distribution width (RDW), platelet number (PLT), white blood cell count (WBC) and lymphocyte count (LYMF) than animals older than 2 years of age. However, they showed the lowest mean cell volume (MCV) and TPP values. In cows, the highest levels of PEOS, granulocytes (GRAN), MCV and medium cells (MID) were observed and the lowest HTC, RBC, RDW and WBC levels. Intervals were determined with the 1st quartile (Q1) or lower confidence interval (90% CI) as the minimum values and the 3rd quartile (Q3) or upper confidence interval (90% CI) as the maximum values. The haematological parameters of cattle reared in the Southeast of Mexico are significantly affected by age, sex and environmental conditions.

Comparison of prepartum blood parameters in dairy cows with postpartum ketosis and new risk prediction candidates

Introduction

Ketosis is a predominant metabolic problem and a risk factor for several postpartum diseases. This retrospective study aimed to evaluate the complete blood count (CBC), plasma biochemistry, and osteocalcin and identify significant prepartum and early postpartum values expressed in ketotic cows.

Methods

In 135 Holstein Friesian cows, 210 parturitions of 114 primiparous and 96 multiparous cows were examined. According to the plasma concentrations of β-hydroxybutyrate (BHB; ≥ 1.4 mmol/L) or non-esterified fatty acids (NEFA; ≥ 0.7 mmol/L) in the postpartum period, cows were divided into healthy cows (CON) and ketotic cows (KET). Analyses of CBC and biochemistry profiles were performed from -6 to 4 weeks of parturition every 2 weeks (prepartum; BW-5, BW-3, and BW-1, postpartum; BW1 and BW3), and osteocalcin ELISA tests were performed using blood samples from -2 to 2 weeks of parturition (BW-1 and BW1).

Results

In primiparous KET (n = 114) before parturition, lower lymphocyte (Lym) in BW-5 and BW-3, lower red blood cell (RBC) in BW-5, higher mean corpuscular volume (MCV) in BW-1, and higher NEFA in BW-3 were significant compared with CON. Primiparous KET showed lower carboxylated osteocalcin (cOC) levels and a significant decrease after parturition. In multiparous KET (n = 96) before parturition, lower neutrophil (Neu) in BW-5, higher hemoglobin (HGB) in BW-5, higher MCV in BW-5 and BW-1, higher MCH in BW-5, lower total cholesterol (TC) in BW-5, higher triglyceride (TG) in BW-3, higher NEFA in BW-1, higher glucose (Glu) in BW-3, lower γ-glutamyl transferase (GGT) in BW-5, lower inorganic phosphate (iP) in BW-3, and higher body condition score (BCS) in BW-5 and BW-3 were significant compared with CON. Multiparous KET showed decreased cOC and uncarboxylated osteocalcin (ucOC) after parturition, which was lower than that in the CON group.

Discussion

The blood parameters expressing different values between CON and KET in prepartum or early postpartum periods are presumed to show individual nutrition and health states, liver function, and overweight status. These parameters could be valuable indicators that can be used to prevent the occurrence of ketosis and improve management practices by recognizing these differences in ketotic cows before calving.

Blood Gas, Acid-Base and Electrolyte Analysis in Healthy Dromedary Camel Calves up to 21 Days of Life

The importance of prompt evaluation and care of the newborn is essential for reducing neonatal mortality, which represents a major cause of loss in camelids. This study investigated the blood gases, acid-base and electrolyte profiles in healthy dromedary calves during the first 3 weeks of life, assessing possible associations with age. Twenty-one dromedary camel calves aged 1 to 21 days were sampled, and venous whole blood analyzed through a VETSTAT® analyzer. The following parameters were measured: sodium (Na⁺), potassium (K⁺), chloride (Cl^-), hydrogen ion concentration (pH), partial pressure carbon dioxide (pCO₂), partial pressure oxygen (pO₂), total hemoglobin concentration (tHb), hemoglobin oxygen saturation (sO₂), total carbon dioxide (tCO₂), bicarbonate (HCO₃^-), base excess (BE) and anion gap (AG). Calves were divided in two groups; younger calves (1-10 d), and older calves (11-21 d). Statistical analysis showed an effect of age, with lower K⁺ (p < 0.001) and higher Na⁺ and Cl^- (p < 0.05) mean concentrations in the younger calves compared to the older ones, and higher pCO₂ and lower sO₂ mean concentrations in the older group. These preliminary results firstly described the blood gas, acid-base and electrolyte profiles in the healthy dromedary calf during the first 3 weeks of age, suggesting an effect of age on some parameters.

Effect of dietary inclusion of mealworm frass on growth, hematology, and serum biochemistry of sheep

Frass is the main component of worm by-product which exhibit anti-microbial and anti-pathogenic properties. In the present study, we assessed the possibility of mealworm frass in sheep feeding regime and evaluated its effect on health and growth performance of sheep. A total of 09 experimental sheep (18-24 months of age) were grouped into three categories (T1, T3, and T3); each group comprised 3 animals including 2 males and 1 female. Group T1 was considered control, group T2 contains 75% commercial feed and 25 mealworm frass, and T3 was 50:50 of commercial feed and mealworm frass. The sheep in group T2 showed average weight gain of 2.9 kg; however, when the dietary inclusion increased up to 50% of mealworm frass or decreased up to 50% of concentrate feed, the average weight gain decreased up to 2.01 kg (group T3). Moreover, the sheep fed with 25% mealworm frass exhibited the lowest feed refusal percentage (6.33%) in total duration of the dietary period (6 weeks). The highest volume of RBC was found in blood collected from sheep fed within group T2 (10.22 10¹²/L ± 0.34), followed by sheep fed in group T3 (8.96 × 10¹²/L ± 0.99) (P < 0.05). Significantly (P < 0.05) highest MCV volume in fL (femtoliter) was found in group T2 (32.83 ± 0.44) followed by group T3 (31.23 ± 0.23). The animals in group T3 showed significantly (P < 0.05) highest MCHC volume (40.47 g/dL ± 0.62) followed by group T2 (38.77 ± 0.97). Similar trend was found in MPV (fL); significantly (P < 0.05) highest MPV volume was found in group T3 (12.63 ± 0.09) followed by group T2 (12.53 ± 0.33). Significantly (P < 0.05) high serum phosphorous (P) (6.00 ± 0.29), TG (60.03 ± 3.11), and TP (7.63 g/dL ± 0.23) levels were found in group T3, followed by animals in group T2. We can conclude that inclusion of mealworm frass to replace 25% commercial concentrate feed improved the growth rate and overall health status of the sheep. The present study laid a foundation for the utilization of the mealworm frass (waste product) in ruminant feeding.

Expression kinetics of cytokines and the humoral antibody response concerning short-term protection induced by radiation-attenuated Trypanosoma evansi in bovine calves

'Surra', an economically important disease of livestock, is caused by the parasitic blood protozoon Trypanosoma evansi. Both innate and adaptive immunity contribute to the protection against this infection. T-helper cells play a crucial role in the antibody-mediated clearance of T. evansi. We present here the data on the kinetics of expression of important Th1, Th2 and Th17 cytokines, vis-a-vis the dynamics of humoral response in bovine calves following immunization with γ-radiation-attenuated live T. evansi and later challenged with homologous virulent T. evansi. Significant upregulation of the pro-inflammatory Th1 and Th17 cytokines was correlated with the IgG2-mediated protection in the immunized bovine calves post-challenge. The calves were immunized with 5 × 10⁶ 500 Gy γ-radiation-attenuated live T. evansi (horse isolate) thrice at 15 days intervals through the subcutaneous route and subsequently, challenged with 1 × 10³ virulent T. evansi on day 50. Significantly high serum IgG (1:1600) and IgM (1:800) titres were recorded on week 2 PC, whereas the peak serum IgG2 titre (1:800) was recorded on week 6 PC. Significant upregulation of IFN-γ, TNF, IL-1β, and IL-2 was recorded between days 1 to 3 PC, while the same for IL-17 was recorded on day 14 PC. The immunized calves were free from parasitemia post-challenge and were clinically healthy till the end of the experiment. Significant upregulation of IL-10 and IL-4 transcripts and a corresponding increase of serum IgG1 titre in the placebo group helped patency of the parasite in an anti-inflammatory environment and clinical exacerbation of the disease. The expression of the important Th1 cytokines was crucial for antibody-mediated short-term protection against a lethal challenge of T. evansi in cattle.

Efficacy of Bentonite and Fumonisin Esterase in Mitigating the Effects of Aflatoxins and Fumonisins in Two Kenyan Cattle Breeds

The objective of the study was to investigate the efficacy of bentonite and fumonisin esterase, separately or combined, in mitigating the effects of aflatoxins (AF) and fumonisins (FUM) in Boran and Friesian-Boran crossbreed cattle. These effects were studied by measuring mycotoxins, their metabolites, and biomarkers that relate to animal health, productivity, and food safety. The study was divided into three experiments each lasting for 2 weeks. Cows in experiment 1 received in random order aflatoxin B1 (AFB1) [788 μg/cow/day (69.7 μg/kg dry matter intake (DMI)) for Borans and 2,310 μg/cow/day (154 μg/kg DMI) for crossbreeds], bentonite (60 g/cow/day), or both AFB1 and bentonite. Boran cows in experiment 2 received in random order FUM (12.4 mg/cow/day (1.1 mg/kg DMI)), fumonisin esterase (120 U/cow/day), or both FUM and fumonisin esterase. Boran cows in experiment 3 received in random order AFB1 (952 μg/cow/day (84.2 μg/kg DMI)) + FUM (30.4 mg/cow/day (2.7 mg/kg DMI)), bentonite (60 g/cow/day) + fumonisin esterase (120 U/cow/day), or both AFB1 + FUM and bentonite + fumonisin esterase. Feeding AFB1 and/or FUM contaminated feed with or without the addition of the detoxifiers for 14 days did not affect DMI, milk composition, hematology, and blood biochemical parameters. The addition of bentonite in a diet contaminated with AFB1 led to a decrease in milk aflatoxin M1 (AFM1) concentration of 30% and 43%, with the carry-over subsequently decreasing from 0.35% to 0.20% and 0.08% to 0.06% for crosses and Borans, respectively. No significant change was observed in the sphinganine/sphingosine (Sa/So) ratio following feeding with FUM alone or in combination with fumonisin esterase; however, the ability of fumonisin esterase to hydrolyze FUM into less toxic fully hydrolyzed FUM and partially hydrolyzed FUM was evident in the rumen fluid and feces. These results indicate bentonite was effective in decreasing AFM1 concentration in milk, and AFB1 and AFM1 in plasma, while fumonisin esterase can convert FUM into less toxic metabolites and can be a suitable addition to feed cocontaminated with AFB1 and FUM.

Comparison of blood gas parameters, ions, and glucose concentration in polish Holstein-Friesian Dairy cows at different milk production levels

Genetic selection for increased milk yield has been a key driver of dairy intensification. The modern dairy cow produces much higher amounts of milk than the cattle of several years ago, and this may have an influence on hematologic values at different stages of lactation and on cows with different levels of milk production. The purpose of the study was to investigate the variations in blood parameters such as Ht, tHb, sO₂, FO₂Hb, FCOHb, FMetHb, FHHb, pH, pCO₂, pO₂, standard HCO₃-, actual HCO₃-, BE, BE ecf, ctCO₂, BO₂, p50, and ctO₂ in cows at different milk production levels. In addition, ions such as Na+, K+ , Ca++, Ca++ (7.4), and Cl-, and AnGap and glucose were examined. Our findings indicated that differences in the examined blood parameters between low and high-production dairy cattle do exist. The most apparent differences were connected with blood pH (p < 0.01), oxygen metabolism (Ht, tHb, sO2, FO2Hb; p < 0.01), and glucose utilization (p < 0.01) The results confirm that the parameters connected with blood oxygen metabolism and glucose metabolism increase significantly in high-production animals. In conclusion, reference values should be considered in light of the lactation stage and level of milk production, because these might influence how changes should be interpreted. The main limitation of the study is the delay to analysis. However, the blood was properly stored (4C), thus changes were delayed. Anyway, it is very hard in the field practice to perform it within 5 min after the blood collection and according to studies it has low impact on clinical outcomes.

Blood Cell Separation Using Polypropylene-Based Microfluidic Devices Based on Deterministic Lateral Displacement

Mammalian blood cell separation methods contribute to improving the diagnosis and treatment of animal and human diseases. Microfluidic deterministic lateral displacement (DLD) devices can sort cells based on their particle diameter. We developed microfluidic DLD devices with poly(propylene)-based resin and used them to separate bovine and human red blood cells (RBCs) and white blood cells (WBCs) without electric devices. To determine the critical cut-off diameter (D_c) of these devices, we used immunobeads with a diameter of 1-20 μm. The D_c values of the microfluidic DLD devices for the immunobeads in the experiments were similar to the calculated D_c values (8-10 μm). Results from bovine blood cell separation experiments suggest that lymphocytes and neutrophils can be separated from diluted, whole blood. Human RBCs were occasionally observed in the left outlet where larger particles with diameters closer to the D_c value were collected. Based on the D_c values, human neutrophils were sorted to the left outlet, whereas lymphocytes were observed in both outlets. Although microfluidic channel optimization is required for the concentration of sorted cells, the microfluidic DLD device prepared with a poly(propylene)-based resin has the potential for clinical use.

A Short-Term Supplementation with a Polyphenol-Rich Extract from Radiata Pine Bark Improves Fatty Acid Profiles in Finishing Lambs

The aim of this study was to evaluate the effects of a short-term supplementation with a polyphenol-rich extract from radiata pine bark (PBE) on animal performance, blood parameters, and fatty acid (FA) profiles in finishing lambs. Twenty-seven Suffolk lambs (4 months old) fed a finishing diet were randomly assigned to one of the following treatments: diet without PBE or diet supplemented with PBE on a 1 or 2% dry matter (DM) basis, for 35 d (14 d adaptation and 21 d of experimental period). Data were compared using Tukey's test and orthogonal and polynomial contrasts. The results indicated that the supplementation with PBE increased (p = 0.008) relative growth rate (RGR) and improved (p = 0.003) protein conversion (CPC), whereas weight gain, carcass characteristic, and blood parameters were unaffected (p ≥ 0.106). Total mono- and polyunsaturated FAs, conjugated linoleic acid (CLA), and vaccenic and oleic acids were linearly increased (p ≤ 0.016) by PBE supplementation. In contrast, total saturated FAs (ΣSFA), Σn-6/Σn-3 ratio, atherogenicity index (AI), thrombogenic index (TI), and the proportion of elaidic acid were linearly decreased (p ≤ 0.018). In conclusion, the supplementation with 1 or 2% DM of PBE improves subcutaneous FA profiles by increasing CLA and reducing ΣSFA, Σn-6/Σn-3 ratio, AI, and TI. Additionally, PBE supplementation has the potential to improve RGR and CPC, with unaffected intake, growth performance, blood parameters, or carcass characteristics.

Effects of wildfire smoke PM2.5 on indicators of inflammation, health, and metabolism of preweaned Holstein heifers

Wildfires are a growing concern as large, catastrophic fires are becoming more commonplace. Wildfire smoke consists of fine particulate matter (PM2.5), which can cause immune responses and disease in humans. However, the present knowledge of the effects of wildfire PM2.5 on dairy cattle is sparse. The present study aimed to elucidate the effects of wildfire-PM2.5 exposure on dairy calf health and performance. Preweaned Holstein heifers (N = 15) were assessed from birth through weaning, coinciding with the 2021 wildfire season. Respiratory rate, heart rate, rectal temperatures, and health scores were recorded and blood samples were collected weekly or twice a week for analysis of hematology, blood metabolites, and acute phase proteins. Hourly PM2.5 concentrations and meteorological data were obtained, and temperature-humidity index (THI) was calculated. Contribution of wildfires to PM2.5 fluxes were determined utilizing AirNowTech Navigator and HYSPLIT modeling. Mixed models were used for data analysis, with separate models for lags of up to 7 d, and fixed effects of daily average PM2.5, THI, and PM2.5 × THI, and calf as a random effect. THI ranged from 48 to 73, while PM2.5 reached concentrations up to 118.8 µg/m3 during active wildfires. PM2.5 and THI positively interacted to elevate respiratory rate, heart rate, rectal temperature, and eosinophils on lag day 0 (day of exposure; all P < 0.05). There was a negative interactive effect of PM2.5 and THI on lymphocytes after a 2-d lag (P = 0.03), and total white blood cells, neutrophils, hemoglobin, and hematocrit after a 3-d lag (all P < 0.02), whereas there was a positive interactive effect on cough scores and eye scores on lag day 3 (all P < 0.02). Glucose and NEFA were increased as a result of combined elevated PM2.5 and THI on lag day 1, whereas BHB was decreased (all P < 0.05). Contrarily, on lag day 3 and 6, there was a negative interactive effect of PM2.5 and THI on glucose and NEFA, but a positive interactive effect on BHB (all P < 0.03). Serum amyloid A was decreased whereas haptoglobin was increased with elevated PM2.5 and THI together on lag days 0 to 4 (all P < 0.05). These findings indicate that exposure to wildfire-derived PM2.5, along with increased THI during the summer months, elicits negative effects on preweaned calf health and performance both during and following exposure.

Maternal nutrient restriction during late gestation reduces vigor and alters blood chemistry and hematology in neonatal beef calves

Fall-calving primiparous beef females [body weight: 451 ± 28 (SD) kg; body condition score: 5.4 ± 0.7] were individually-fed either 100% (control; CON; n = 13) or 70% (nutrient restricted; NR; n = 13) of metabolizable energy and metabolizable protein requirements for maintenance, pregnancy, and growth from day 160 of gestation to parturition. Calves were reared naturally by their dams and monitored for latency times from birth to first sternal recumbency, attempt to stand, and stand; vigor scores were assigned at 2, 5, 10, and 20 min of age. Rectal temperatures and jugular blood were obtained at 0 (pre-suckling), 6, 12, 24, and 48 h of age, and blood chemistry, hematology, cortisol, and insulin were determined. Data were analyzed with fixed effects of late gestational nutritional plane (single data point) or nutritional plane, hour, and their interaction (data over time, repeated measures). Calving date was a fixed effect; calf sex was included when P < 0.25. We previously reported that late gestational nutritional plane did not affect gestation length or calf size at birth, but calving assistance and fetal malpresentation occurred more often in NR. Nutritional plane did not affect (P = 0.65) duration of parturition, but calves born to NR dams had slower times to attempt to stand (P = 0.09), slower times to stand (P = 0.02), and poorer 20 min vigor scores (P = 0.05). Serum immunoglobulin G and A concentrations at 48 h were greater (P ≤ 0.03) for NR calves. Rectal temperature of NR calves was less (P = 0.02) at 0 h, but greater (P = 0.04) at 24 h compared with CON. Circulating glucose, non-esterified fatty acids, triglycerides, cortisol, and insulin were not affected by nutritional plane (P ≥ 0.18). Total protein and globulin from 6 to 48 h were greater (P ≤ 0.02) in NR calves. Calves from NR dams had greater (P ≤ 0.08) gamma-glutamyl transferase at 6, 12, and 48 h. Serum aspartate aminotransferase was greater (P ≤ 0.07) from 0 to 24 h and creatine kinase was greater (P ≤ 0.04) from 6 to 24 h in NR calves. At 0 h, potassium was greater (P = 0.03) in NR calves. Calves born to CON had greater chloride (P = 0.08; main effect), sodium (P ≤ 0.09) from 0 to 48 h, and anion gap (P = 0.02) at 6 h. Hematocrit from 6 to 24 h and red blood cells and hemoglobin at 6 and 12 h were greater (P ≤ 0.09) in CON calves. These data indicate that nutrient restriction during late gestation resulted in less vigorous calves with more indicators of trauma in early life.

Whole blood transcriptome analysis in dairy calves experimentally challenged with bovine herpesvirus 1 (BoHV-1) and comparison to a bovine respiratory syncytial virus (BRSV) challenge

Bovine herpesvirus 1 (BoHV-1), is associated with several clinical syndromes in cattle, among which bovine respiratory disease (BRD) is of particular significance. Despite the importance of the disease, there is a lack of information on the molecular response to infection via experimental challenge with BoHV-1. The objective of this study was to investigate the whole-blood transcriptome of dairy calves experimentally challenged with BoHV-1. A secondary objective was to compare the gene expression results between two separate BRD pathogens using data from a similar challenge study with BRSV. Holstein-Friesian calves (mean age (SD) = 149.2 (23.8) days; mean weight (SD) = 174.6 (21.3) kg) were either administered BoHV-1 inoculate (1 × 10⁷/mL × 8.5 mL) (n = 12) or were mock challenged with sterile phosphate buffered saline (n = 6). Clinical signs were recorded daily from day (d) -1 to d 6 (post-challenge), and whole blood was collected in Tempus RNA tubes on d six post-challenge for RNA-sequencing. There were 488 differentially expressed (DE) genes (p < 0.05, False Discovery rate (FDR) < 0.10, fold change ≥2) between the two treatments. Enriched KEGG pathways (p < 0.05, FDR <0.05); included Influenza A, Cytokine-cytokine receptor interaction and NOD-like receptor signalling. Significant gene ontology terms (p < 0.05, FDR <0.05) included defence response to virus and inflammatory response. Genes that are highly DE in key pathways are potential therapeutic targets for the treatment of BoHV-1 infection. A comparison to data from a similar study with BRSV identified both similarities and differences in the immune response to differing BRD pathogens.

Effects of supplemental zinc on growth, carcass characteristics, and liver abscess formation in steers with experimentally induced ruminal acidosis challenge

The study's aim was to evaluate the effect of dietary Zn supplementation on steer performance, biomarkers of inflammation and metabolism, and liver abscess formation in response to a mild acidosis challenge. Forty-two steers (417 ± 3.99 kg; n = 6/pen) were housed in pens with bunks designed to measure individual dry matter intake (DMI) and fed one of two diets containing either 0 (CON; n = 18) or 90 mg Zn/kg from a Zn-amino acid complex (Zn-AA; n = 18; AvailaZn; Zinpro) for 109 d. Six additional steers were fed the CON diet and did not undergo the acidosis challenge (NON; n = 6). The acidosis challenge included restricting steers to 50% of the previous 7 d daily DMI on days 46 and 47, steers were individually provided 10% of DMI as cracked corn (as-fed) at 0800 h followed by ad libitum feed access 2 h post-grain consumption. Steer was the experimental unit, and two contrasts were constructed: NON vs. CON and CON vs. Zn-AA. Blood samples were collected on days 40, 48, 53, 69, 80, and 108 and analyzed as repeated measures. Final body weight and overall average daily gain (2.29, 2.30, and 2.31 ± 0.920 kg/d for CON, Zn-AA, and NON, respectively) were not different (P ≥ 0.74) between treatments. By design, DMI was greater (P < 0.01) for NON compared to CON on day 46 but was not different (P ≥ 0.41) for the rest of the experiment. While hot carcass weight (423, 428, and 424 ± 7.9 kg for CON, Zn-AA, and NON, respectively) and ribeye area were not different (P ≥ 0.53) due to treatment, marbling score tended (P = 0.06) to be greater in CON compared to Zn-AA. The 12th rib backfat thickness was greater (P = 0.05) in NON vs. CON steers. Liver abscess incidence tended to be greater (P = 0.12) in CON (24% abscesses) vs. Zn-AA (6% abscesses). NON had a greater incidence (P = 0.05; 50% abscesses) compared to CON. Overall, blood fibrinogen and leukocyte counts were not different between treatments (P ≥ 0.67); however, neutrophil-to-lymphocyte ratio tended to be greater in NON vs. CON (P = 0.08). Serum aspartate aminotransferase and gamma-glutamyl transferase concentrations were greater in NON vs. CON (P ≤ 0.02), and serum alkaline phosphatase concentration was lesser in CON vs. Zn-AA (P < 0.01). Overall, dietary Zn supplementation tended to lessen incidence of liver abscesses with limited impacts on overall cattle performance. Shifts in liver enzymes may represent opportunities to identify cattle with liver abscesses earlier in the feeding period.

Molecular, Physiological and Hematological Responses of Crossbred Dairy Cattle in a Tropical Savanna Climate

A comprehensive study was conducted to assess the effects of seasonal transition and temperature humidity index (THI) on the adaptive responses in crossbred dairy cows reared in a tropical savanna region. A total of 40 lactating dairy cattle reared by small-scale dairy farmers in Bengaluru, India, were selected for this study. The research period comprised the transitioning season of summer to monsoon, wherein all traits were recorded at two points, one representing late summer (June) and the other early monsoon (July). A set of extensive variables representing physiological responses (pulse rate, respiration rate, rectal temperature, skin surface temperature), hematological responses (hematological profile), production (test day milk yield, milk composition) and molecular patterns (PBMC mRNA relative expression of selective stress response genes) were assessed. A significant effect of seasonal transition was identified on respiration rate (RR), skin surface temperature, mean platelet volume (MPV), platelet distribution width (PDWc), test day milk yield and on milk composition variables (milk density, lactose, solids-not-fat (SNF) and salts). The THI had a significant effect on RR, skin surface temperature, platelet count (PLT), plateletcrit (PCT) and PDWc. Lastly, THI and/or seasonal transition significantly affected the relative PBMC mRNA expression of heat shock protein 70 (HSP70), interferon beta (IFNβ), IFNγ, tumor necrosis factor alpha (TNFα), growth hormone (GH) and insulin-like growth factor-1 (IGF-1) genes. The results from this study reveal environmental sensitivity of novel physiological traits and gene expressions to climatic stressors, highlighting their potential as THI-independent heat stress biomarkers.

Effect of Thermal Stress on Thermoregulation, Hematological and Hormonal Characteristics of Caracu Beef Cattle

This study evaluated the influence of environmental temperature on thermoregulation, hormonal, and hematological characteristics in Caracu cattle. Blood samples, hair length, coat and muzzle colors, rectal (RT), and surface temperatures were collected from 48 males and 43 females before (morning) and after sun exposure for eight hours (afternoon). Infrared thermography (IRT) was used to identify superficial temperature that exhibits a high correlation with RT. Hematological parameters, hormone concentrations, RT, and the superficial temperature obtained by IRT that exhibited the highest correlation with RT were evaluated by variance analysis. Regarding IRT, the lower left side of the body (LS) showed the highest correlation with the RT. Interaction between period and sex was observed for LS, cortisol, and eosinophils. Cortisone, progesterone, and RT were influenced by period and sex. Neutrophils and segmented neutrophils were influenced by the period, which showed the highest concentrations after sun exposure. Platelets, leukocytes, lymphocytes, and monocytes were influenced by sex. Heat stress changes several physiological characteristics where males and females exhibited differences in their responses to heat stress. Furthermore, most characteristics evaluated remained within the regular values observed for taurine Creole breeds, showing that Caracu is adapted to tropical climates.