Invited review: Relationship between cattle transport, immunity and respiratory disease

Evaluation of antimicrobial and non-steroidal anti-inflammatory treatments for BRD on health and welfare in fattening bulls: a cross-sectional study

Our study aimed to evaluate the effect of different treatments for BRD on health and welfare in fattening bulls. A total of 264 bulls were enrolled. Welfare was assessed on day 2 (T0) and day 15 (T1) after arrival. A decrease in the welfare level was observed from T0 to T1. All bulls were inspected clinically at T0 and T1 revealing an increase of skin lesions and lameness in T1. In both periods, a high incidence of respiratory disease was observed. A prevalence of 79.55% and 95.45% of Mycoplasma bovis using RT-PCR and culture at T0 and T1 respectively was observed. Blood samples were collected for haematology at T0 and T1. At T0, 36 animals were individually treated for BRD with an antimicrobial (IT), 54 received a metaphylactic treatment with tulathromycin (M), 150 received a metaphylactic treatment with tulathromycin plus a second antimicrobial (M + IT) whereas 24 were considered healthy and therefore not treated (NT). Additionally, 128 were treated with a non-steroid anti-inflammatory (NSAID). Neutrophils of M + IT were significantly higher than groups NT and M and the lymphocytes of M + IT were significantly lower than that of IT. White blood cells, neutrophils and N/L ratio of animals treated with an NSAID was significantly higher than that not treated. Lung inspection of 172 bulls at the abattoir indicated that 92.43% presented at least one lung lesion. A statistically significant effect of the NSAID treatment on the lung lesions was observed. Our findings indicate that BRD was a major welfare and health concern and evidence the difficulties of antimicrobial treatment of M. bovis.

Consequences of Transport Conditions on the Welfare of Slaughter Pigs with Different Health Status and RYR-1 Genotype

This study assessed the influence of transport conditions on welfare indicators of slaughter pigs with different health status and RYR-1 genotype. The group of pigs, predominantly consisting of Nn (56.67%) and subclinically diseased (60.00%) individuals, that were exposed to short transportation (<30 min) at high loading density (~235 kg/m2) had the highest slipping (p < 0.0001), falling (p = 0.0009), turning back (p < 0.0001), reluctance to move (p < 0.0001), panting (p < 0.0001) and shivering (p < 0.0001) frequencies at unloading. Subclinically diseased Nn pigs subjected to short transportation (<30 min) and high loading density (~235 kg/m2) had the highest lactate (p < 0.0001 and p < 0.0001), glucose (p = 0.0450 and p = 0.0002), CK (p < 0.0001 and p = 0.0010), LDH (p < 0.0001 and p = 0.0484), AST (p = 0.0208 and p = 0.0170), ALT (p = 0.0500 and p = 0.00081), ceruloplasmin (p = 0.0334 and p < 0.0001) and MDA (p = 0.0048 and p < 0.0001) concentrations, but the lowest sodium (p < 0.0001 and p < 0.0001), chloride (p = 0.0001 and p = 0.0432), albumin (p < 0.0090 and p < 0.0001), PON-1 (p = 0.0122 and p = 0.0500) and GSH (p = 0.0042 and p = 0.0340) levels, respectively. In the group consisting of of stress-resistant (100%) and predominantly healthy (60.00%) pigs subjected to short transportation (<30 min) at high loading density (~235 kg/m2), none of the individuals showed irregular behavioural reactions during unloading. Healthy NN pigs that underwent short transportation (<30 min) at high loading density (~235 kg/m2) had the lowest lactate (p < 0.0001 and p < 0.0001), glucose (p = 0.0450 and p = 0.0002), CK (p < 0.0001 and p = 0.0010), LDH (p < 0.0001 and p = 0.0484) and ceruloplasmin (p = 0.0334 and p < 0.0001) levels, but the highest sodium (p < 0.0001 and p < 0.0001) and chloride (p = 0.0001 and p = 0.0432) concentrations, respectively. In conclusion, the most compromised welfare was recorded in subclinically diseased Nn pigs exposed to short transportation (<30 min) and high loading density (~235 kg/m2), while under the same conditions, the welfare of healthy NN pigs was not compromised. Therefore, stress-carrier pigs with subclinical pathological lesions should not be considered fit for transportation, indicating that the health status and genotype are the key factors for optimising pig welfare.

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 vitamin E and selenium administration on transportation stress in pregnant dairy heifers

We investigated the effects of road transportation and administration of the vitamin E and selenium (ESe) on circulating cortisol, haptoglobin, blood metabolites, oxidative biomarkers, white blood cell profiles, and behaviors in pregnant dairy heifers. Forty pregnant Holstein heifers were randomly assigned to one of 4 treatments: no transportation and no ESe administration, no transportation and ESe administration, transportation and no administration, and transportation and ESe administration. The ESe (70 IU/kg dry matter feed of dl-α-tocopheryl acetate and 0.3 mg/kg dry matter feed of sodium selenite) was orally delivered once a day from 7 d before transportation to 3 d after transportation. The heifers were transported in trucks designed for cattle transportation. Blood was collected 1 h before transportation, immediately after transportation (IAT), and at 6, 24, and 48 h after transportation. Behaviors were recorded using a video camera for 2 consecutive days after transportation. Transported/non-ESe-administered heifers had greater cortisol at IAT, haptoglobin at 6 and 24 h after transportation, total oxidative status at 6 h after transportation, and nonesterified fatty acid levels, white blood cell numbers, and neutrophil percentages at IAT and 6 h after transportation in the blood than nontransported heifers. Transported/non-ESe-administered heifers had lower total antioxidative status levels at 48 h after transportation and lymphocyte percentages at IAT and 6 h after transportation than nontransported heifers. Lying time was shorter in transported heifers than nontransported/non-ESe-administered heifers. Transported/ESe-administered heifers had lower cortisol, total oxidative status, nonesterified fatty acid levels at IAT, and haptoglobin concentrations at 6 and 24 h after transportation than transported/non-ESe-administered heifers. Transported/ESe-administered heifers had greater total antioxidative status levels at 48 h after transportation than transported/non-ESe-administered heifers. No ESe administration effects were observed for white blood cell number and neutrophil and lymphocyte percentages and lying time. In conclusion, road transportation caused temporary oxidative stress. Administrating ESe partially alleviated the stress, suggesting that ESe administration could be a viable strategy to reduce stress in transported pregnant heifers, providing a novel role of vitamin E and selenium for improving animal welfare.

Current Knowledge on the Transportation by Road of Cattle, including Unweaned Calves

Transport conditions have the potential to alter the physiological responses of animals to the psychological or physical stress of transport. Transportation may introduce multiple physical and psychological stressors to unweaned calves and adult cattle, including noise, overcrowding, food and water deprivation, extreme temperatures, commingling with unfamiliar animals, handling by unfamiliar humans, and being placed in a novel environment upon arrival. Apart from these factors, the type of road and even driving skill may affect the welfare of animals. One of the concerns regarding cattle transport is that the handling and marketing of animals prior to a journey may lengthen the period of feed withdrawal. Furthermore, feed withdrawal can impact animal welfare through hunger and metabolic stress. Transportation is also associated with a decrease in animal performance as well as an increase in the incidence of bovine respiratory disease. It is well established that the transportation of cattle is a stressor that causes a quantifiable response; however, excessive stress during transport resulting in physiological or pathological changes can be reduced with best management practices. The objective of this review was to analyse the available scientific literature pertaining to the transport by road of cattle, including unweaned calves.

Effect of source and journey on physiological variables in calves transported by road and ferry between Ireland and the Netherlands

This study aimed to establish baseline variables for calves transported by road and ferry from Ireland to the Netherlands and to investigate the effect of journey [two comparable journeys in April (J1) and May (J2) 2022] and source [source farm or mart (SF/MA)] on these variables. A total of 66 calves from the SF/MA were transported from Ireland to commercial veal farms in the Netherlands. Blood samples were collected at the SF/MA, assembly center (Ireland), lairage (France), and on arrival on the veal farm (Netherlands). They were analyzed for indicator variables related to energy balance, hydration/electrolytes, physical/muscular stress, immunity, and inflammation [glucose, beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), potassium, sodium, magnesium, chloride, urea, haematocrit, total protein, creatine kinase, L-lactate, cortisol, white blood cell, neutrophil, lymphocyte and monocyte counts, serum amyloid-A, and haptoglobin]. Health variables eye and nose discharge, skin tent (a measure of dehydration), and navel inflammation were scored by a trained observer, and calves were weighed at every blood-sampling time point. All blood variables and body weight changed significantly (P < 0.05) during transport, most notably between the assembly center and lairage. Reference ranges were available for 18 variables; 11 of these variables exceeded the reference ranges at the lairage, whilst 10 variables exceeded the reference ranges on arrival at the veal farm. However, health variables did not change during transport. A journey-to-journey comparison indicated much variation; 18 out of 25 variables differed significantly on at least one time point. In total, J1 calves experienced a more severe change in BHB, potassium, strong-ion-difference, L-lactate, and eye and nose discharge than J2 calves. The source of calves also affected their physiology; 12 out of 25 variables studied differed significantly, all of which were confined to the first time point. Specifically, MA calves had elevated levels of NEFA, urea, haematocrit, L-lactate, cortisol, white blood cell, neutrophil, and monocyte counts and lower levels of corrected chloride and lymphocyte count. Overall, calves in this study showed a generalized physiological disturbance beyond reference limits during long-distance transport, but no animal died during transport or for 3 weeks post-arrival.

Effects of bovine respiratory disease on the plasma metabolome of beef steers during the receiving period

The study aimed to investigate the impact of Bovine Respiratory Disease (BRD) on the metabolism of beef steers during a 35-d receiving period using plasma metabolomics. In this study, 77 newly weaned crossbred (Angus × Hereford) beef steers (BW = 206 ± 12 kg and age = 180 ± 17 days) were categorized into two groups: Healthy and Sick groups. The Sick group comprised beef steers diagnosed with BRD at any time during the 35-day period (n = 31), while the Healthy group did not show any signs of BRD (n = 46). Blood samples were collected from the coccygeal vessels on day 35, and plasma samples were subjected to targeted metabolomics analysis using Nuclear Magnetic Resonance spectroscopy. Data and statistical analyses, including biomarker and pathway enrichment analyses, were performed using Metaboanalyst 5.0. Results of the growth performance showed that sick steers had lower (p ≤ 0.05) ADG (1.44 vs. 1.64 kg/d) and higher (p = 0.01) feed:gain ratio (3.57 vs. 3.13) compared to healthy steers. A total of 50 metabolites were quantified. The partial least squares discriminant scores plot showed a slight separation between the two groups of steers, indicating some metabolic differences. Furthermore, the plasma concentrations of four metabolites (sarcosine, methionine, dimethyl sulfone, and L-histidine) were greater (p ≤ 0.05) in healthy steers compared to sick steers. Among these metabolites, sarcosine and methionine qualified as candidate biomarkers associated with BRD infection based on an area under the curve >0.70. Additionally, quantitative enrichment analysis revealed that cysteine and methionine metabolism was enriched in healthy steers compared to sick steers. This suggests that these metabolic pathways may play a role in the response to BRD infection. The findings of this study highlight the altered plasma metabolome in steers with BRD during the receiving period. Understanding these metabolic changes can contribute to the development of effective management strategies and nutritional interventions to mitigate the negative impact of BRD on beef cattle health and immune function.

Evaluation of the Immune Response to Transport Stress in the Aosta Valley Breed

Transportation is a recurring event in a farm animal's life, and it is considered one of the main stressors with possible negative repercussions for both the health and welfare of farm animals. The objective of the present study was to examine the effect of transportation on some blood variables of 45 young bulls moved from their original farms to a livestock collection centre. Transportation took no more than 8 h and was carried out between January and March 2021. Blood samples were taken before transportation (T0), upon arrival at the collection centre (T1), and 7 days after arrival (T2). Samples were processed for blood cell count, clinical chemistry analyses, serum protein electrophoresis, and the evaluation of innate immunity parameters. The results showed a typical stress leukogram with neutrophilia and changes in the neutrophil:lymphocyte ratio. No significant alterations were observed in either serum proteins or pro-inflammatory cytokines. Significant, albeit transient, alterations were observed in some clinical chemistry parameters after transportation, which could be accounted for by stressful conditions such as the transportation itself and handling and mixing with other animals. Our results indicated that the adopted transportation conditions only slightly affected the blood variables under study with no significant impact on animal welfare.

RAGE-TLR4 Crosstalk Is the Key Mechanism by Which High Glucose Enhances the Lipopolysaccharide-Induced Inflammatory Response in Primary Bovine Alveolar Macrophages

The receptor of advanced glycation end products (RAGE) and Toll-like receptor 4 (TLR4) are important receptors for inflammatory responses induced by high glucose (HG) and lipopolysaccharide (LPS) and show crosstalk phenomena in inflammatory responses. However, it is unknown whether RAGE and TLR4 can influence each other's expression through a crosstalk mechanism and whether the RAGE-TLR4 crosstalk related to the molecular mechanism of HG enhances the LPS-induced inflammatory response. In this study, the implications of LPS with multiple concentrations (0, 1, 5, and 10 μg/mL) at various treatment times (0, 3, 6, 12, and 24 h) in primary bovine alveolar macrophages (BAMs) were explored. The results showed that a 5 μg/mL LPS treatment at 12 h had the most significant increment on the pro-inflammatory cytokine interleukin 1β (IL-1β), IL-6, and tumor necrosis factor (TNF)-α levels in BAMs (p < 0.05) and that the levels of TLR4, RAGE, MyD88, and NF-κB p65 mRNA and protein expression were upregulated (p < 0.05). Then, the effect of LPS (5 μg/mL) and HG (25.5 mM) co-treatment in BAMs was explored. The results further showed that HG significantly enhanced the release of IL-1β, IL-6, and TNF-α caused by LPS in the supernatant (p < 0.01) and significantly increased the levels of RAGE, TLR4, MyD88, and NF-κB p65 mRNA and protein expression (p < 0.01). Pretreatment with FPS-ZM1 and TAK-242, the inhibitors of RAGE and TLR4, significantly alleviated the HG + LPS-induced increment of RAGE, TLR4, MyD88, and NF-κB p65 mRNA and protein expression in the presence of HG and LPS (p < 0.01). This study showed that RAGE and TLR4 affect each other's expression through crosstalk during the combined usage of HG and LPS and synergistically activate the MyD88/NF-κB signaling pathway to promote the release of pro-inflammatory cytokines in BAMs.

Livestock haulers' views about dairy cattle transport in Atlantic Canada

Surplus dairy calves and cull cows are often transported from the dairy farm to a variety of destinations and may experience compromised health and welfare in the process. Increasing interest in farm animal welfare by many stakeholders, including the public and policymakers, has brought about recent changes to livestock transport regulations in Canada that have likely affected transport operations across the country. The Atlantic region may be especially affected as a result of a smaller number of farms, and geography that often requires cattle to be transported long distances. We interviewed 7 livestock haulers in Atlantic Canada regarding their attitudes toward the recent changes to the transport regulations, particularly with regard to how these changes affected their business practices and dairy cattle welfare, as certain regulatory changes pertaining to calf transport were expected to disrupt existing transport practices. Thematic analysis of interview transcripts revealed 2 themes among participants: (1) calf (and sometimes adult cow) welfare and management during transport and on the dairy farm, and (2) feasibility of transport requirements and the enforcement of the regulations, including animosity toward other haulers and the challenge of satisfying both regulatory bodies and farmer clientele. These findings provide insight into the perspectives of an important, and often overlooked, stakeholder in the dairy industry on the transport system and highlight the need for inclusion of diverse voices when creating new policy.

The effects of administering different metaphylactic antimicrobials on growth performance and health outcomes of high-risk, newly received feedlot steers

Bovine respiratory disease (BRD) is the primary animal health concern facing feedlot producers. Many antimicrobial mitigation strategies are available, but few studies have compared feedlot performance during both the receiving and finishing periods following application of different antimicrobials used as metaphylaxis at arrival. The objective of this study was to compare antimicrobial metaphylaxis methods on clinical health and growth performance across both the receiving and finishing periods. A total of 238 multiple-sourced steers in two source blocks were used in a generalized complete block design. The four treatments included: 1) a negative control, 5 mL of sterile saline injected subcutaneously (CON); 2) subcutaneous administration of florfenicol at 40 mg/kg of BW (NUF); 3) subcutaneous administration of ceftiofur in the posterior aspect of the ear at 6.6 mg/kg of BW (EXC); and 4) subcutaneous administration of tulathromycin at 2.5 mg/kg of BW (DRA). The morbidity rate for the first treatment of BRD was decreased for the DRA and EXC treatments compared to CON and NUF (P &lt; 0.01). Additionally, average daily gain (ADG), dry matter intake (DMI), and gain-to-feed (G:F) were greater (P ≤ 0.02) in the DRA treatment during the receiving period compared to all other treatments. The ADG was also greater (P &lt; 0.05) for EXC than the CON treatment throughout the finishing period. Nonetheless, other growth performance variables did not differ among metaphylactic treatments during the finishing period (P ≥ 0.14). Likewise, no differences in carcass characteristics or liver abscess score were observed (P ≥ 0.18). All complete blood count (CBC) variables were affected by day (P ≤ 0.01) except mean corpuscular hemoglobin concentration (P = 0.29). Treatment × time interactions were observed for platelet count, white blood cell (WBC) count, monocyte count and percentage, and lymphocyte percentage (P ≤ 0.03). However, there were no observed hematological variables that differed among treatment (P ≥ 0.10). The results indicate that some commercially available antimicrobials labeled for metaphylactic use are more efficacious than others in decreasing morbidity rate.

Welfare of cattle during transport

In the framework of its Farm to Fork Strategy, the Commission is undertaking a comprehensive evaluation of the animal welfare legislation. The present Opinion deals with protection of cattle (including calves) during transport. Welfare of cattle during transport by road is the main focus, but other means of transport are also covered. Current practices related to transport of cattle during the different stages (preparation, loading/unloading, transit and journey breaks) are described. Overall, 11 welfare consequences were identified as being highly relevant for the welfare of cattle during transport based on severity, duration and frequency of occurrence: group stress, handling stress, heat stress, injuries, motion stress, prolonged hunger, prolonged thirst, respiratory disorders, restriction of movement, resting problems and sensory overstimulation. These welfare consequences and their animal-based measures are described. A variety of hazards, mainly relating to inexperienced/untrained handlers, inappropriate handling, structural deficiencies of vehicles and facilities, poor driving conditions, unfavourable microclimatic and environmental conditions, and poor husbandry practices leading to these welfare consequences were identified. The Opinion contains general and specific conclusions relating to the different stages of transport for cattle. Recommendations to prevent hazards and to correct or mitigate welfare consequences have been developed. Recommendations were also developed to define quantitative thresholds for microclimatic conditions within the means of transport and spatial thresholds (minimum space allowance). The development of welfare consequences over time was assessed in relation to maximum journey duration. The Opinion covers specific animal transport scenarios identified by the European Commission relating to transport of unweaned calves, cull cows, the export of cattle by livestock vessels, the export of cattle by road, roll-on-roll-off ferries and 'special health status animals', and lists welfare concerns associated with these.

The combination of high glucose and LPS induces autophagy in bovine kidney epithelial cells via the Notch3/mTOR signaling pathway

BACKGROUND

Aside respiratory diseases, beef cattle may also suffer from serious kidney diseases after transportation. Hyperglycemia and gram-negative bacterial infection may be the main reasons why bovine is prone to severe kidney disease during transportation stress, however, the precise mechanism is still unclear. The purpose of the current study is to explore whether the combined treatment of high glucose (HG) and lipopolysaccharide (LPS) could induce madin-darby bovine kidney (MDBK) cells injury and autophagy, as well as investigate the potential molecular mechanisms involved.

RESULTS

As we discovered, the combined effect of HG and LPS decreased MDBK cells viability. And, HG and LPS combination also induced autophagy in MDBK cells, which was characterized by increasing the expression of LC3-II/I and Beclin1 and decreasing p62 expression. LC3 fluorescence signal formation was also significantly increased by HG and LPS combination treatment. Furthermore, we measured whether the mammalian target of rapamycin (mTOR) and the Notch3 signaling pathways were involved in HG and LPS-induced autophagy. The results showed that the combination of HG and LPS significantly increased the protein expression of Notch3 and decreased protein expression of p-mTOR, indicating that Notch3 and mTOR signaling pathways were activated. However, co-treatment with the Notch3 inhibitor (DAPT) could reverse the induction of autophagy, and increased the protein expression of p-mTOR.

CONCLUSIONS

This study demonstrated that the combination effect of HG and LPS could induce autophagy in MDBK cells, and the Notch3/mTOR signaling pathway was involved in HG and LPS-induced autophagy.

Bacteria associated with infectious keratoconjunctivitis outbreak in confined lambs

Introduction. Infectious keratoconjunctivitis is a significant ocular disease found in confined sheep. Little information about the aetiological agents and their antimicrobial susceptibility is available.Gap Statement. There is limited information on the aetiological agents involved in keratoconjunctivitis outbreaks in sheep.Aim. The present research aimed to determine the bacterial aetiological factors involved in an outbreak of infectious keratoconjunctivitis in confined lambs.Methodology. Ocular swabs were collected from 23 randomly selected lambs, which were classified into three groups according to the severity of the lesion: group I (N=6; no ocular involvement), group II (N=8; less severe injuries) and group III (N=9; more severe injuries). Isolation of aerobic bacteria and antimicrobial susceptibility tests were carried out. Molecular detection of Mollicutes was performed, and positive samples were tested to confirm the presence of the following species: Mycoplasma conjunctivae, Mycoplasma agalactiae and Mycoplasma mycoides subsp. capri.Results. Moraxella sp. and Mollicutes were detected in all groups, but we inferred that Moraxella sp. are only significant in the early stages of the disease. M. conjunctivae was detected in all tested groups, while M. agalactiae was detected in samples of group III only. One strain of Moraxella sp. was resistant to erythromycin and showed intermedite resistance to tetracycline.Conclusion. The presence of these species confirms their importance in the aetiology of this disease, and the low resistance profile observed in the studied farm suggested an increased cure success rate.

Preparing Male Dairy Calves for the Veal and Dairy Beef Industry

Surplus male dairy calves experience significant health challenges after arrival at the veal and dairy beef facilities. To curb these challenges, the engagement of multiple stakeholders is needed starting with improved care on some dairy farms and better management of transportation. Differing management strategies are also needed if calves arrive at veal and dairy beef facilities under poor condition.

Effect of Farm Management Practices on Morbidity and Antibiotic Usage on Calf Rearing Farms

Antimicrobial resistance has been recognized as one of the top health threats to human society. Abundant use of antibiotics in both humans and animals has led to ever-increasing antibiotic resistance in bacteria. In food production, decreasing morbidity in beef herds would be an effective way to reduce the use of antibiotics. The objective of this retrospective observational study was to determine overall morbidity on calf rearing farms and to identify associated risk factors. Data were collected by questionnaire, meat companies’ databases and the national cattle register for 28,228 calves transported to 87 calf rearing farms. All medications given to these calves were retrospectively followed for 180 days from calf arrival to the farm. In total, 34,532 parenteral antibiotic medications were administered to the 28,228 study calves (122.3%), and 17,180 calves (60.9%) were medicated with antibiotics at least once during the follow-up. Higher numbers of calves transported to the same farm and larger age variation in calves in the same arrival batch were both associated with increased morbidity. In contrast, higher arrival age of individual calves was associated with decreased morbidity. Our study identifies several factors to consider in decreasing morbidity and antibiotic usage on calf rearing farms.

Lack of Fetal Protection against Bovine Viral Diarrhea Virus in a Vaccinated Heifer

The aim of the report was to present the circulation of BVDV (bovine viral diarrhea virus) in the cattle population and determine the cause of the failure of vaccination failure leading to the birth of the PI (persistently infected) calf. The case study was carried out at the BVDV-free animal breeding center and cattle farm, where the vaccination program against BVDV was implemented in 2012, and each newly introduced animal was serologically and virologically tested for BVDV. In this case, a blood sample was taken from a 9-month-old breeding bull. Positive RT-PCR and negative ELISA serology results were obtained. The tests were repeated at 2-week intervals, and the results confirmed the presence of the virus and the absence of specific antibodies, i.e., persistent infection. Additionally, sequencing and phylogenetic analysis were performed, and the BVDV-1d subgenotype was detected. The results of this study showed that pregnant heifers and cows that are vaccinated multiple times with the killed vaccine containing BVDV-1a may not be fully protected against infection with other subgenotypes of BVDV, including their fetuses, which can become PI calves.

Multipopulational transcriptome analysis of post-weaned beef cattle at arrival further validates candidate biomarkers for predicting clinical bovine respiratory disease

Bovine respiratory disease (BRD) remains the leading infectious disease in post-weaned beef cattle. The objective of this investigation was to contrast the at-arrival blood transcriptomes from cattle derived from two distinct populations that developed BRD in the 28 days following arrival versus cattle that did not. Forty-eight blood samples from two populations were selected for mRNA sequencing based on even distribution of development (n = 24) or lack of (n = 24) clinical BRD within 28 days following arrival; cattle which developed BRD were further stratified into BRD severity cohorts based on frequency of antimicrobial treatment: treated once (treated_1) or treated twice or more and/or died (treated_2+). Sequenced reads (~ 50 M/sample, 150 bp paired-end) were aligned to the ARS-UCD1.2 bovine genome assembly. One hundred and thirty-two unique differentially expressed genes (DEGs) were identified between groups stratified by disease severity (healthy, n = 24; treated_1, n = 13; treated_2+, n = 11) with edgeR (FDR ≤ 0.05). Differentially expressed genes in treated_1 relative to both healthy and treated_2+ were predicted to increase neutrophil activation, cellular cornification/keratinization, and antimicrobial peptide production. Differentially expressed genes in treated_2+ relative to both healthy and treated_1 were predicted to increase alternative complement activation, decrease leukocyte activity, and increase nitric oxide production. Receiver operating characteristic (ROC) curves generated from expression data for six DEGs identified in our current and previous studies (MARCO, CFB, MCF2L, ALOX15, LOC100335828 (aka CD200R1), and SLC18A2) demonstrated good-to-excellent (AUC: 0.800–0.899; ≥ 0.900) predictability for classifying disease occurrence and severity. This investigation identifies candidate biomarkers and functional mechanisms in at arrival blood that predicted development and severity of BRD.

Parameters of nonspecific resistance of calves with respiratory pathology before and after treatment

Objective

The research was conducted to study the effect of a complex antimicrobial drug with an anti-inflammatory effect and an antimicrobial drug with an immunostimulating effect on the parameters of nonspecific resistance in calves.

Materials and Methods

Two groups (n = 5 each) of sick calves with respiratory pathology were selected for this study. For the treatment of the first experimental group, a complex antimicrobial drug Sulfetrisan^® was used. The second experimental group of the calves was intramuscularly injected with the experimental drug gentaaminoseleferon (GIA). To assess the cellular component of immunity in the blood before and after treatment, the number of white blood cells, T-lymphocytes, B-lymphocytes, phagocytic activity of leukocytes, phagocytic number, and phagocytic index (PhI) were determined. In addition, for assessing the humoral component, serum complement activity (SCA), serum lysozyme activity, serum bactericidal activity (SBA), circulating immune complexes (CIC), and total immunoglobulins (total Ig) were measured. The results were compared with the baseline parameters of healthy calves of the control group.

Results

When studying the parameters of the humoral and cellular components of nonspecific resistance, it was found that in sick animals, compared with healthy ones, respiratory pathology was accompanied by an imbalance in the immune system. In the process of recovery in animals of the experimental groups under the effect of the drugs, positive changes occurred. However, many of the studied parameters did not reach the values of healthy animals. In the group of calves that received GIA, compared with the calves given Sulfetrisan^®, a significant increase in PhI (p < 0.05), SBA (p < 0.006), SCA (p < 0.05), total Ig (p < 0.0005), and CIC (p < 0.05) was observed, which indicated an increase in natural resistance due to the immunostimulating action.

Conclusion

The use of GIA in sick animals added to an increase in the general nonspecific cellular and humoral resistance of calves, which made it possible to increase therapeutic efficacy and shorten their recovery time.

Metagenomics Reveals That Proper Placement After Long-Distance Transportation Significantly Affects Calf Nasopharyngeal Microbiota and Is Critical for the Prevention of Respiratory Diseases

Transportation is an inevitable phase for the cattle industry, and its effect on the respiratory system of transported cattle remains controversial. To reveal cattle’s nasopharyngeal microbiota dynamics, we tracked a batch of beef calves purchased from an auction market, transported to a farm by vehicle within 3 days, and adaptively fed for 7 days. Before and after the transport and after the placement, a total of 18 nasopharyngeal mucosal samples were collected, and microbial profiles were obtained using a metagenomic shotgun sequencing approach. The diversity, composition, structure, and function of the microbiota were collected at each time point, and their difference was analyzed. The results showed that, before the transportation, there were a great abundance of potential bovine respiratory disease (BRD)-related pathogens, and the transportation did not significantly change their abundance. After the transportation, 7 days of placement significantly decreased the risk of BRD by decreasing the abundance of potential BRD-related pathogens even if the diversity was decreased. We also discussed the controversial results of transportation’s effect in previous works and the decrease in diversity induced by placement. Our work provided more accurate information about the effect of transportation and the followed placement on the calf nasopharyngeal microbial community, indicated the importance of adaptive placement after long-distance transport, and is helpful to prevent BRD induced by transportation stress.

Factors Affecting the Development of Bovine Respiratory Disease: A Cross-Sectional Study in Beef Steers Shipped From France to Italy

Bovine respiratory disease (BRD) is a complex, multifactorial syndrome and one of the major welfare and economical concerns for the cattle industry. This 1-year cross-sectional study was aimed at documenting the prevalence of BRD-related pathogens and clinical signs before and after a long journey and at identifying possible predisposition factors. Male Limousine beef steers (n = 169) traveling from France to Italy were health checked and sampled with Deep Nasopharyngeal Swabs (DNS) at loading (T0) and 4 days after arrival (T1). Real-time quantitative PCR was used to quantify the presence of bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine alphaherpesvirus 1 (BoHV-1), bovine coronavirus (BCoV), bovine adenovirus (BAdV), bovine parainfluenza virus 3 (BPIV-3), Histophilus somni, Mannheimia haemolytica, Mycoplasma bovis, and Pasteurella multocida. Weather conditions at departure and arrival were recorded, and the travel conditions were taken from the travel documentation. At T0, even if no animals displayed clinical signs, some of them were already positive for one or more pathogens. At T1, the number of animals displaying clinical signs and positive for BCoV, BAdV, BRSV, H. somni, M. haemolytica, M. bovis, and P. multocida increased dramatically (p < 0.001). Transport also significantly increased co-infection passing from 16.0% at T0 to 82.8% at T1 (p < 0.001). An extra stop during the journey seemed to favor BRSV, M. haemolytica, and P. multocida (p < 0.05). Weather conditions, in particular sudden climate changes from departure to arrival and daily temperature variance, were found to be predisposing factors for many of the pathogens. The farm of arrival also played a role for BRSV, BAdV, and H. somni (p < 0.05). BCoV increased dramatically, but no associations were found confirming that it spreads easily during transport phases. Our findings increased our understanding of factors increasing the likelihood of BRD-related pathogens shedding and can be useful to minimize the incidence of BRD and to implement animal transport regulations.

CHALLENGES TO ANIMAL WELFARE DURING TRANSPORTATION OF WILD MAMMALS: A REVIEW (1990-2020)

Wild mammal transport is an important component of conservation translocation as well as the economic wildlife trade. This article reviews the physiological responses to transport that have been measured in wild mammalian species, factors associated with these responses, and interventions that have been applied to mitigate these responses. By organizing the literature review along the "five domains model" of animal welfare, namely, the physical-functional domains (nutrition, environment, health, behavior) and the mental domain (mental state), it can be demonstrated that wild mammal transport is associated with challenges to ensuring positive animal welfare in all five domains. Transported wild mammals can experience dehydration, catabolism, fatigue, immunosuppression, behavioral changes, and stress. Factors influencing these physiological responses to transport have only been researched in a few studies encompassing species, journey length, ambient temperature, vehicle motion, stocking density, orientation, habituation, vehicle speed allowance, and road type. The administration of tranquilizers has been shown to mitigate negative physiological responses to transport. There is a need to further investigate species and situation-specific physiological responses to transport and factors associated with these responses in order to identify challenges to ensuring animal welfare and improving translocation success.

Portable Electronic Nose for Analyzing the Smell of Nasal Secretions in Calves: Toward Noninvasive Diagnosis of Infectious Bronchopneumonia

The paper demonstrates a new approach to identify healthy calves (“healthy”) and naturally occurring infectious bronchopneumonia (“sick”) calves by analysis of the gaseous phase over nasal secretions using 16 piezoelectric sensors in two portable devices. Samples of nasal secretions were obtained from 50 red-motley Holstein calves aged 14–42 days. Calves were subjected to rectal temperature measurements, clinical score according to the Wisconsin respiratory scoring chart, thoracic auscultation, and radiography (Carestream DR, New York, USA). Of the 50 calves, we included samples from 40 (20 “healthy” and 20 “sick”) in the training sample. The remaining ten calves (five “healthy” and five “sick”) were included in the test sample. It was possible to divide calves into “healthy” and “sick” groups according to the output data of the sensor arrays (maximum sensor signals and calculated parameters A_i/j) using the principal component linear discriminant analysis (PCA–LDA) with an accuracy of 100%. The adequacy of the PCA–LDA model was verified on a test sample. It was found that data of sensors with films of carbon nanotubes, zirconium nitrate, hydroxyapatite, methyl orange, bromocresol green, and Triton X-100 had the most significance for dividing samples into groups. The differences in the composition of the gaseous phase over the samples of nasal secretions for such a classification could be explained by the appearance or change in the concentrations of ketones, alcohols, organic carboxylic acids, aldehydes, amines, including cyclic amines or those with a branched hydrocarbon chain.

Association between clinical respiratory signs, lung lesions detected by thoracic ultrasonography and growth performance in pre-weaned dairy calves

Background

Bovine respiratory disease (BRD) is the main cause of mortality among 1-to-5 month old calves in Ireland, accounting for approximately one-third of deaths. Despite widespread use of clinical respiratory signs for diagnosing BRD, lung lesions are detected, using thoracic ultrasonography (TUS) or following post-mortem, in calves showing no clinical signs. This highlights the limitation of clinical respiratory signs as a method of detecting sub-clinical BRD. Using 53 purchased artificially-reared male dairy calves, the objectives of this study were to: (i) characterise the BRD incidence detected by clinical respiratory signs and/or TUS, (ii) investigate the association between clinical respiratory signs and lung lesions detected by TUS, and (iii) assess the effect of BRD on pre-weaning growth.

Results

Clinical BRD (based on Wisconsin clinical respiratory score and/or rectal temperature > 39.6 ºC) was detected in 43 % and sonographic changes (lung lesions) were detected in 64 % of calves from purchase (23 (SD; 6.2) days of age) until weaning, 53 days post-arrival. Calves with clinical BRD were treated. Sixty-one per cent calves affected with clinical BRD had lung lesions 10.5 days (median) before detection of clinical signs. Moderate correlations (r_sp 0.70; P < 0.05) were found between cough and severe lung lesions on arrival day, and between rectal temperature > 39.6 ºC and lung lesions ≥ 2 cm² on day 7 (r_sp 0.40; P < 0.05) post-arrival. Mean average daily live weight gain (ADG) of calves from purchase to weaning was 0.75 (SD; 0.10) kg; calves with or without clinical BRD did not differ in ADG (P > 0.05), whereas ADG of those with severe lung lesions (lung lobe completely consolidated or pulmonary emphysema) was 0.12 kg/d less (P < 0.05) than calves without lung lesions.

Conclusions

Thoracic ultrasonography detected lung consolidation in calves that did not show signs of respiratory disease. The presence of severe lung lesions was associated with reduced pre-weaning growth. These findings emphasise the importance of using TUS in addition to clinical respiratory scoring of calves for an early and accurate detection of clinical and sub-clinical BRD.

Cytokine and Haptoglobin Profiles From Shipping Through Sickness and Recovery in Metaphylaxis- or Un-Treated Cattle

Fifty-six head of cattle, 28 animals with bovine respiratory disease complex (BRDC), and 28 healthy animals that were matched by treatment, sale barn of origin, day, and interactions among these variables, were identified from a population of 180 animals (60 each purchased at three sale barns located in Missouri, Tennessee, and Kentucky) enrolled in a study comparing animals receiving metaphylaxis to saline-treated controls. Cattle were transported to a feedlot in KS and assigned to treatment group. Blood samples were collected at Day 0 (at sale barn), Day 1, Day 9, and Day 28 (at KS feedlot), and transported to the US Meat Animal Research Center in Clay Center, NE where plasma was harvested and stored at −80°C until assayed for the cytokines IFN-γ, IL-1β, IL-6, and TNF-α, and the acute stress protein haptoglobin (HPT). Our objectives were to determine if cytokine and haptoglobin profiles differed between control and metaphylaxis treatment groups over time, and if profiles differed between animals presenting with BRDC and those that remained healthy. There was no difference between the treated animals and their non-treated counterparts for any of the analytes measured. Sale barn of origin tended to affect TNF-α concentration. Differences for all analytes changed over days, and on specific days was associated with state of origin and treatment. The Treatment by Day by Case interaction was significant for HPT. The analyte most associated with BRDC was HPT on D9, possibly indicating that many of the cattle were not exposed to respiratory pathogens prior to entering the feedlot.

Analysis of lung transcriptome in calves infected with Bovine Respiratory Syncytial Virus and treated with antiviral and/or cyclooxygenase inhibitor

Bovine Respiratory Syncytial virus (BRSV) is one of the major infectious agents in the etiology of the bovine respiratory disease complex. BRSV causes a respiratory syndrome in calves, which is associated with severe bronchiolitis. In this study we describe the effect of treatment with antiviral fusion protein inhibitor (FPI) and ibuprofen, on gene expression in lung tissue of calves infected with BRSV. Calves infected with BRSV are an excellent model of human RSV in infants: we hypothesized that FPI in combination with ibuprofen would provide the best therapeutic intervention for both species. The following experimental treatment groups of BRSV infected calves were used: 1) ibuprofen day 3-10, 2) ibuprofen day 5-10, 3) placebo, 4) FPI day 5-10, 5) FPI and ibuprofen day 5-10, 6) FPI and ibuprofen day 3-10. All calves were infected with BRSV on day 0. Daily clinical evaluation with monitoring of virus shedding by qRT-PCR was conducted. On day10 lung tissue with lesions (LL) and non-lesional (LN) was collected at necropsy, total RNA extracted, and RNA sequencing performed. Differential gene expression analysis was conducted with Gene ontology (GO) and KEGG pathway enrichment analysis. The most significant differential gene expression in BRSV infected lung tissues was observed in the comparison of LL with LN; oxidative stress and cell damage was especially noticeable. Innate and adaptive immune functions were reduced in LL. As expected, combined treatment with FPI and Ibuprofen, when started early, made the most difference in gene expression patterns in comparison with placebo, especially in pathways related to the innate and adaptive immune response in both LL and LN. Ibuprofen, when used alone, negatively affected the antiviral response and caused higher virus loads as shown by increased viral shedding. In contrast, when used with FPI Ibuprofen enhanced the specific antiviral effect of FPI, due to its ability to reduce the damaging effect of prostanoids and oxidative stress.

Effects of pre-transport diet, transport duration and transport condition on immune cell subsets, haptoglobin, cortisol and bilirubin in young veal calves

The aim of this study was to investigate effects of pre-transport diets, transport durations and transport conditions on immune cell subsets, haptoglobin, cortisol and bilirubin of young calves upon arrival at the veal farm. An experiment was conducted with a 2 × 2 × 2 factorial arrangement with 3 factors: 1) provision of rearing milk or electrolytes at the collection center (CC); 2) transport duration (6 or 18 hours) and 3) transport condition (open truck or conditioned truck). Holstein-Friesian and cross-bred calves were used (N = 368; 18 ± 4 days; 45.3 ± 3.3 kg). Blood samples were collected from calves (N = 128) at the collection center, immediately post-transport (T0) and 4, 24, 48 hours, week 1, 3 and 5 post-transport. Blood was analyzed for cortisol, bilirubin, haptoglobin, IgG and IgM. Moreover, cell counts of neutrophils, lymphocytes, monocytes, basophils and eosinophils were measured in blood samples taken at the collection center and T0. In these same blood samples, different lymphocyte populations were characterized by flow cytometry, including CD14+ cells, NK cells, δγ+ T cells, CD8+ cells, CD4+ cells and CD21+ cells. Calves transported in the conditioned truck had higher amounts of white blood cell count (WBC) (Δ = 1.39 × 10⁹/l; P = 0.01), monocytes (Δ = 0.21 × 10⁹/l; P = 0.04), neutrophils (Δ = 0.93 × 10⁹/l; P = 0.003), than calves transported in the open truck regardless, of pre-transport diet or transport duration. The study showed that transport condition and duration influenced parts of the innate immune system of young veal calves. Cortisol, bilirubin and WBC seemed to be connected by similar underlying mechanisms in relation to transport conditions. However, it is unclear which specific pathways in the immune system of young calves are affected by different transport conditions (e.g. temperature, humidity, draught).

Growth performance and hematological changes of weaned beef calves diagnosed with respiratory disease using respiratory scoring and thoracic ultrasonography

This study investigated 1) the effect of clinical bovine respiratory disease (BRD) and associated lung consolidations on growth performance and hematological profiles of recently weaned beef calves and 2) the relationship between clinical respiratory signs and lung consolidation detected by thoracic ultrasonography (TUS). One hundred and fifty-three weaned beef calves (209 days old [SD: 35.8] and 306 kg [SD: 26.3], at arrival) purchased and transported from auction markets were accommodated indoors in concrete slatted floor pens. Calves were weighed weekly from arrival until day 28 and on day 65 post-arrival. Assessment of BRD and blood sample collection for hematological profiles were performed on scheduled days (at arrival, on days 7, 14, and 28) and on other days upon BRD diagnosis. Animals were assessed for BRD using a total clinical respiratory score (CRS) of five clinical signs (rectal temperature, ear position, cough, nasal secretion, and eye secretion with each ranging from normal [0] to abnormal [3]) and TUS scores (normal [0] to lung consolidation ≥ 1 cm2 [2]). Based on CRS, 35% of calves were CRS+ (CRS ≥ 5) and 65% were CRS- (CRS < 5). Although no lung consolidations (TUS-) were detected at arrival, 34% of calves developed lung consolidation (≥1 cm2) (TUS+) during the first 28 d post-arrival. Only fever (>39.6 °C) and nasal discharge were weakly associated (r = 0.19, P <0.05) with lung consolidation. On the day of BRD detection, neutrophil number and neutrophil:lymphocyte ratio were 58% and 73% greater, respectively, in BRD calves with lung consolidation compared with healthy calves. From day 0 to 65, calf average daily gain (ADG) did not differ (P >0.05) between CRS+ and CRS- calves but was 0.09 kg/d lower (P < 0.05) for TUS+ compared with TUS- calves. Calves classified as BRD (CRS + TUS ≥ 5) with lung consolidation had lower (P < 0.05) ADG from arrival until day 28 than healthy calves and BRD calves without lung consolidation (0.11 ± 0.10 vs. 0.53 ± 0.07 vs. 0.57 ± 0.10 kg/d, respectively); however, no differences in ADG were observed from day 0 to 65. Conventional methods to diagnose BRD failed to detect calves with lung lesions. TUS is a useful tool to detect lung lesions and its implementation in combination with CRS should provide a more accurate and early diagnosis of BRD, which is fundamental to successful treatment, animal welfare, and growth performance.

An Investigation into the Perceptions of Veterinarians towards Calf Welfare in New Zealand

Despite recent legislative amendments to address areas of highest risk to the welfare of calves (Bos taurus) in New Zealand, there are prevailing concerns that animal welfare science knowledge has not been adopted in practice. As a part of a larger, nationwide study investigating the perceptions of veterinarians towards calf welfare, the aim of the current work was to investigate the perceptions of veterinarians towards the level of welfare protection afforded to young "bobby" calves in New Zealand. This study also explored concerns for welfare compromise and identified barriers to welfare-related change for calves more generally. An electronic mixed-methods survey was completed by 104 veterinarians registered with the Veterinary Council of New Zealand. The findings revealed that veterinarians strongly disagreed with the specifications of certain calf welfare regulations. Veterinarians also identified areas at highest risk of calf welfare compromise across the production chain and barriers to welfare-related change. These findings demonstrate considerable support among veterinarians for improving the level of welfare protection afforded to calves. Given the discrepancies that exist between the current regulatory regime and veterinary perspectives, the knowledge gained from this study can be used in support of regulatory reform to strengthen calf welfare in practice and policy in New Zealand.

Co-infection best predicts respiratory viral infection in a wild host

The dynamics of directly transmitted pathogens in natural populations are likely to result from the combined effects of host traits, pathogen biology, and interactions among pathogens within a host. Discovering how these factors work in concert to shape variation in pathogen dynamics in natural host-multi-pathogen systems is fundamental to understanding population health. Here, we describe temporal variation in incidence and then elucidate the effect of hosts trait, season and pathogen co-occurrence on host infection risk using one of the most comprehensive studies of co-infection in a wild population: a suite of seven directly transmitted viral and bacterial respiratory infections from a 4-year study of 200 free-ranging African buffalo Syncerus caffer. Incidence of upper respiratory infections was common throughout the study-five out of the seven pathogens appeared to be consistently circulating throughout our study population. One pathogen exhibited clear outbreak dynamics in our final study year and another was rarely detected. Co-infection was also common in this system: The strongest indicator of pathogen occurrence for respiratory viruses was in fact the presence of other viral respiratory infections. Host traits had minimal effects on odds of pathogen occurrence but did modify pathogen-pathogen associations. In contrast, only season predicted bacterial pathogen occurrence. Though a combination of environmental, behavioural, and physiological factors work together to shape disease dynamics, we found pathogen associations best determined infection risk. Our study demonstrates that, in the absence of very fine-scale data, the intricate changes among these factors are best represented by co-infection.

Selecting sorting centres to avoid long distance transport of weaned beef calves

The transport of weaned calves from cow–calf producers to fatteners is a general concern for the young bull industry due to its documented negative impact on the welfare, health and performance of the animals. These transfers are often managed by intermediaries who transport weaned calves to sorting centres, where they are grouped into batches before being sent to fattening units. In this study, we present an algorithm to limiting these transfer distances by appropriately selecting the sorting centre through which they must go. We tested the effectiveness of this algorithm on historical data from a French beef producer organization managing 136,892 transfers using 13 sorting centres. The results show a decrease in the transfer distances compared to the historical record, especially for the calves travelling over long distances (− 76 km, i.e. 18% on average for the 33% longest transfers). Moreover, the distribution of calves between the sorting centres proposed by the algorithm reveals differences in their efficiency in minimizing transfer distances. In addition to its usefulness as a management tool for the daily transport of cattle, this algorithm provides prospects for improving the management of the sorting centres themselves.

Minimizing the number of origins in batches of weaned calves to reduce their risks of developing bovine respiratory diseases

Bovine respiratory diseases (BRD) are a major concern for the beef cattle industry, as beef calves overwhelmingly develop BRD symptoms during the first weeks after their arrival at fattening units. These cases occur after weaned calves from various cow-calf producers are grouped into batches to be sold to fatteners. Cross-contaminations between calves from different origins (potentially carrying different pathogens), together with increased stress because of the process of batch creation, can increase their risks of developing BRD symptoms. This study investigated whether reducing the number of different origins per batch is a strategy to reduce the risk of BRD cases. We developed an algorithm aimed at creating batches with as few origins as possible, while respecting constraints on the number and breed of the calves. We tested this algorithm on a dataset of 137,726 weaned calves grouped into 9701 batches by a French organization. We also computed an index assessing the risks of developing BRD because of the batch composition by considering four pathogens involved in the BRD system. While increasing the heterogeneity of batches in calf bodyweight, which is not expected to strongly impact the performance, our algorithm successfully decreased the average number of origins in the same batch and their risk index. Both this algorithm and the risk index can be used as part of decision tool to assess and possibly minimize BRD risk at batch creation, but they are generic enough to assess health risk for other production animals, and optimize the homogeneity of selected characteristics.

First expert elicitation of knowledge on drivers of emergence of influenza D in Europe

The influenza D virus (IDV) was first identified and characterized in 2011. Considering the virus' zoonotic potential, its genome nature (segmented RNA virus), its worldwide circulation in livestock and its role in bovine respiratory disease, an increased interest is given to IDV. However, few data are available on drivers of emergence of IDV. We first listed fifty possible drivers of emergence of IDV in ruminants and swine. As recently carried out for COVID-19 in pets (Transboundary and Emerging Diseases, 2020), a scoring system was developed per driver and scientific experts (N = 28) were elicited to (a) allocate a score to each driver, (b) weight the drivers' scores within each domain and (c) weight the different domains among themselves. An overall weighted score was calculated per driver, and drivers were ranked in decreasing order. Drivers with comparable likelihoods to play a role in the emergence of IDV in ruminants and swine in Europe were grouped using a regression tree analysis. Finally, the robustness of the expert elicitation was verified. Eight drivers were ranked with the highest probability to play a key role in the emergence of IDV: current species specificity of the causing agent of the disease; influence of (il)legal movements of live animals (ruminants, swine) from neighbouring/European Union member states and from third countries for the disease to (re-)emerge in a given country; detection of emergence; current knowledge of the pathogen; vaccine availability; animal density; and transport vehicles of live animals. As there is still limited scientific knowledge on the topic, expert elicitation of knowledge and multi-criteria decision analysis, in addition to clustering and sensitivity analyses, are very important to prioritize future studies, starting from the top eight drivers. The present methodology could be applied to other emerging animal diseases.

Strategies for Feeding Unweaned Dairy Beef Cattle to Improve Their Health

In order to answer the question of whether nutritional interventions may help to reduce the incidence of respiratory disease in dairy beef calves at arrival, the present review is divided in three sections. In the first section, the nutrition of calves previous to the arrival from the origin farm to the final rearing farm is reviewed. In the second section, the possible consequences of this previous nutrition on gut health and immune status upon arrival to the rearing farm are described. The main consequences of previous nutrition and management that these unweaned calves suffer at arrival are the negative energy balance, the increased intestinal permeability, the oxidative stress, the anemia, and the recovery feed consumption. Finally, in the third section, some considerations to advance in future nutritional strategies are suggested, which are focused on the prevention of the negative consequences of previous nutrition and the recovery of the gut and immune status. Moreover, additional suggestions are formulated that will be also helpful to reduce the incidence of bovine respiratory disease (BRD) that are not directly linked to nutrition like having a control golden standard in the studies or designing risk categories in order to classify calves as suitable or not to be transported.

Emerging Influenza D virus infection in European livestock as determined in serology studies: Are we underestimating its spread over the continent?

Influenza D virus (IDV) is a novel orthomyxovirus that was first isolated in 2011 in the United States from a swine exhibiting influenza-like disease. To date, its detection is extended to all continents and in a broad host range: IDV is circulating in cattle, swine, feral swine, camelids, small ruminants and horses. Evidence also suggests a possible species jump to humans, underlining the issue of zoonotic potential. In Europe, serological investigations in cattle have partially allowed the understanding of the virus diffusion in different countries such as Italy, France, Luxembourg and Ireland. The infection is widespread in cattle but limited in other investigated species, consolidating the assumption of cattle as IDV primary host. We hypothesize that commercial livestock trade could play a role in the observed differences in IDV seroprevalence among these areas. Indeed, the overall level of exposure in cattle and swine in destination countries (e.g. Italy) is higher than in origin countries (e.g. France), leading to the hypothesis of a viral shedding following the transportation of young cattle abroad and thus contributing to larger diffusion at countries of destination. IDV large geographic circulation in cattle from Northern to more Southern European countries also supports the hypothesis of a viral spread through livestock trade. This review summarizes available data on IDV seroprevalence in Europe collected so far and integrates unpublished data from IDV European surveillance framework of the last decade. In addition, the possible role of livestock trade and biosecurity measures in this pathogen's spread is discussed.

Longitudinal blood transcriptomic analysis to identify molecular regulatory patterns of bovine respiratory disease in beef cattle

Bovine respiratory disease (BRD) is the most common disease in beef cattle and leads to considerable economic losses in both beef and dairy cattle. It is important to uncover the molecular mechanisms underlying BRD and to identify biomarkers for early identification of BRD cattle in order to address its impact on production and welfare. In this study, a longitudinal transcriptomic analysis was conducted using blood samples collected from 24 beef cattle at three production stages in the feedlot: 1) arrival (Entry group); 2) when identified as sick (diagnosed as BRD) and separated for treatment (Pulled); 3) prior to marketing (Close-out, representing healthy animals). Expressed genes were significantly different in the same animal among Entry, Pulled and Close-out stages (false discovery rate (FDR) < 0.01 & |Fold Change| > 2). Beef steers at both Entry and Pulled stages presented obvious difference in GO terms (FDR < 0.05) and affected biological functions (FDR < 0.05 & |Z-score| > 2) when compared with animals at Close-out. However, no significant functional difference was observed between Entry and Pulled animals. The interferon signaling pathway showed the most significant difference between animals at Entry/Pulled and Close-out stages (P < .001 & |Z-score| > 2), suggesting the animals initiated antiviral responses at an early stage of infection. Six key genes including IFI6, IFIT3, ISG15, MX1, and OAS2 were identified as biomarkers to predict and recognize sick cattle at Entry. A gene module with 169 co-expressed genes obtained from WGCNA analysis was most positively correlated (R = 0.59, P = 6E-08) with sickness, which was regulated by 11 transcription factors. Our findings provide an initial understanding of the BRD infection process in the field and suggests a subset of novel marker genes for identifying BRD in cattle at an early stage of infection.

Non-specific protection from respiratory tract infections in cattle generated by intranasal administration of an innate immune stimulant

Alternatives to antibiotics for prevention of respiratory tract infections in cattle are urgently needed given the increasing public and regulatory pressure to reduce overall antibiotic usage. Activation of local innate immune defenses in the upper respiratory tract is one strategy to induce non-specific protection against infection with the diverse array of viral and bacterial pathogens associated with bovine respiratory disease complex (BRDC), while avoiding the use of antibiotics. Our prior studies in rodent models demonstrated that intranasal administration of liposome-TLR complexes (LTC) as a non-specific immune stimulant generated high levels of protection against lethal bacterial and viral pathogens. Therefore, we conducted studies to assess LTC induction of local immune responses and protective immunity to BRDC in cattle. In vitro, LTC were shown to activate peripheral blood mononuclear cells in cattle, which was associated with secretion of INFγ and IL-6. Macrophage activation with LTC triggered intracellular killing of Mannheimia hemolytica and several other bacterial pathogens. In studies in cattle, intranasal administration of LTC demonstrated dose-dependent activation of local innate immune responses in the nasopharynx, including recruitment of monocytes and prolonged upregulation (at least 2 weeks) of innate immune cytokine gene expression by nasopharyngeal mucosal cells. In a BRDC challenge study, intranasal administration of LTC prior to pathogen exposure resulted in significant reduction in both clinical signs of infection and disease-associated euthanasia rates. These findings indicate that intranasal administration of a non-specific innate immune stimulant can be an effective method of rapidly generating generalized protection from mixed viral and bacterial respiratory tract infections in cattle.

Effect of anti-inflammatory compounds or antibiotic administration on receiving performance and physiological responses of transported heifers

The objectives of this experiment was to evaluate the effects of products with anti-inflammatory properties (yeast product [YEA; 20 g/heifer daily] or astragalus polysaccharide [APS; 20 g/heifer daily]) or an antibiotic (TUL, tulathromycin; 0.025 mL/kg body weight [BW]) on receiving performance and stress responses of transported heifers. Angus heifers (n = 80) were ranked by BW (315 ± 6 kg) and assigned to one of four treatments (five pens per treatment, four heifers per pen) 7 d before shipping 1,400 km (day -7): 1) fed a basal diet of ad libitum hay and concentrate supplement (CON) from day -7 to day 29; 2) YEA in supplemental concentrate from day -7 to day 7 (YEA); 3) APS in supplemental concentrate from day -7 to day 7 (APS); 4) administration of TUL at loading for shipping (day 0; TUL). Upon arrival at the receiving facility (day 1), heifers within each treatment were ranked by BW and assigned to 20 feedlot pens in the same manner as pre-transport. Daily dry matter intake (DMI) was recorded from day 1 to day 28. Full BW was recorded on days -7, -1, 0, 1, 28, and 29. Blood samples were collected on days -7, -1, 1, 4, 7, 14, and 28. Over the receiving period, average daily gain (ADG) and gain: feed did not differ (P ≥ 0.19) for YEA, APS, and TUL, which were greater (P ≤ 0.01) than CON. Average daily gain was also lower (P < 0.01) for CON vs. YEA, APS, and TUL from day -7 to day 28. During the first week of receiving, hay, concentrate, and total DMI were lower (P < 0.01) in CON than the YEA, APS, and TUL, but did not differ (P ≥ 0.13) among these three groups. Hay and total DMI were still lower (P < 0.01) in CON vs. TUL in the second week. Total DMI was greater (P = 0.01) for TUL vs. YEA, and greater (P < 0.01) for YEA vs. CON. Serum nonesterified fatty acid concentrations were greater (P ≤ 0.05) for CON and TUL vs. YEA and APS on day 1. Plasma cortisol concentrations were greater (P ≤ 0.05) for YEA and CON vs. APS and TUL on day 1. Serum tumor necrosis factor-α concentrations were lower (P ≤ 0.05) for APS vs. CON, YEA, and TUL on days 1 and 4. Plasma haptoglobin concentrations were greater (P ≤ 0.05) for CON vs. YEA, APS, and TUL on days 1 and 4, greater (P ≤ 0.05) for YEA, APS vs. TUL on day 1, and greater (P = 0.03) for YEA vs. TUL on day 4. Plasma ceruloplasmin concentrations were greater (P ≤ 0.05) for CON vs. YEA, APS and TUL vs. APS on days 1, 4, and 7. In conclusion, YEA, APS, and TUL modulated the physiological stress responses and alleviated the performance losses caused by long-distance transportation.

Field Trial of Primary and Booster Dose of Inactivated Vaccine Against Bovine Respiratory Bacteria in Young Holstein Calves

Introduction

The objective of this research was to evaluate the antibody response to multiple doses of an inactivated mixed vaccine against Histophilus somni, Pasteurella multocida, and Mannheimia haemolytica, and to investigate the influence of age at time of vaccination in the field.

Material and Methods

Healthy female Holstein calves received the vaccine at the age of 5–12 days and 2, 3, or 4 weeks later in the first experiment or at 1, 2, or 3 weeks of age and 4 weeks later in the second. Blood samples were collected at each vaccination and 3 weeks after the booster dose. Based on the antibody titres after the vaccinations, calves were divided into positive and negative groups for each of the bacteria. Calves in the control group were vaccinated only once at the age of 19–26 days.

Results

Antibody titres against H. somni and P. multocida were significantly increased by the booster. After the second vaccinations, the titres against each bacterium were higher than those of the control group, and the M. haemolytica-positive percentage in calves with high maternal antibody levels (MAL) exceeded that in calves with low MAL. In the first experiment, a majority of the M. haemolytica-positive calves tended to have received the primary dose at seven days of age or older.

Conclusion

A booster dose of the inactivated bacterial vaccine in young Holstein calves increased antibody production and overcame the maternal antibodies. Calves should be vaccinated first at seven days of age or older.

Effect of transport and rest stop duration on the welfare of conditioned cattle transported by road

The effects of providing rest on physiological and behavioural indicators of welfare of cattle being transported by road has not been well studied in North America. New revisions to Canada's Health of Animals Regulations Part XII: Transportation of Animals indicate un-weaned and weaned calves can be transported a maximum of 12 and 36 h, respectively, before an 8 h rest is required. Therefore, the aim of this study was to assess the effects of rest duration, after 12 and 36 h of transport, on physiological and behavioural indicators of welfare in 7-8 mo-old beef calves. Three hundred and twenty conditioned calves (258 ± 23.9 kg BW) were randomly assigned to a 2 × 4 factorial design where the main factors included transport duration: 12 h (12; n = 160) and 36 h (36; n = 160) and rest stop duration: 0 h (R0; n = 80), 4 h (R4; n = 80), 8 h (R8; n = 80) and 12 h (R12; n = 80). After the resting period, animals were transported for an additional 4 h. Blood and hair samples were taken from 12 animals per treatment prior to and after the first and the 4 h transport; and then 7 h, 2 d and 28 d after the 4 h transport. The concentrations of haptoglobin, creatine kinase, non-esterified fatty acids (NEFA), lactate, and serum and hair cortisol were determined. Standing and lying behaviour was assessed for 14 d after transport, while feeding behaviour of calves in one pen per treatment were assessed for 28 d after transportation using an electronic feed bunk monitoring system. Body weight (BW), average daily gain (ADG) and shrink (%) was assessed for all calves. The data was modeled using generalized linear mixed methods (SAS PROC GLIMMIX), where transport and time (nested in rest) were considered fixed effects and animal and pen were considered random effects. Statistically significant (p < 0.05) effects of transport were observed on BW and shrink, where 36 h-transported calves had lower (p < 0.01) BW and greater (p < 0.01) shrink than 12 h-transported calves. A transport × time (nested in rest) interaction (p < 0.01) was observed for lying percentage where, 36-R8 calves had greater (p < 0.01) lying percentage than 12-R8 calves on d 1 after transportation. The area under the curve (AUC) for NEFA was greater (p < 0.01) for 36-R0 calves than 12-R0, 36-R4, and 36-R8 calves, and greater (p < 0.01) in 36-R12 calves than 12-R12 calves. Haptoglobin AUC was greater (p = 0.05) in 36-R12 than 12-R12 calves. Overall, physiological indicators of reduced welfare were greater in calves transported for 36 than 12 h, while no clear differences were observed between rest stop groups with the exception of NEFA. Based on these results, conditioned calves benefit from shorter transport durations but there was no clear evidence that calves rested 4, 8, and 12 h following transportation experienced reduced transport related stress compared to those that were not rested (0h).

Effects of pretransport diet, transport duration, and type of vehicle on physiological status of young veal calves

This study aimed to investigate effects of pretransport diet (rearing milk vs. electrolytes), type of vehicle (open vs. conditioned truck), and transport duration (6 vs. 18 h) on physiological status of young calves upon arrival at the veal farm. A total of 368 calves were transported in 2 consecutive batches from a collection center to a veal farm. Blood samples were collected from calves before transport; immediately posttransport (T0); and 4, 24, and 48 h, and 1, 3, and 5 wk posttransport. Blood was analyzed for glucose, urea, lactate, nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), creatine kinase, albumin, total protein, osmolality, calcium, sodium, magnesium, and hematological variables. Body weight, rectal temperature, and skin elasticity were determined before and immediately posttransport. Blood glucose, NEFA, and urea concentrations at T0 showed an interaction between pretransport diet and transport duration. Milk-fed and electrolyte-fed calves transported for 18 h did not significantly differ in plasma glucose concentration or serum NEFA concentrations. However, after 6 h of transport, milk-fed calves had higher plasma glucose and lower serum NEFA concentrations (4.71 mmol/L and 586.5 µmol/L, respectively) than electrolyte-fed calves (3.56 mmol/L and 916 µmol/L, respectively). After 18 h of transport, milk-fed calves had lower urea concentrations (5.40 mmol/L) than electrolyte-fed calves (7.38 mmol/L). In addition, at T0, after 6 h of transport, milk-fed calves gained weight (Δ = 0.41 kg), whereas electrolyte-fed calves lost weight (Δ = -0.16 kg). After 18 h of transport, both milk-fed and electrolyte-fed calves showed body weight losses (Δ = -0.67 and -0.74 kg, respectively). Type of vehicle had a limited influence on blood parameters. Concentrations of NEFA and BHB reached the maximum values at T0 and then decreased until wk 5 posttransport. The increase in NEFA and BHB concentrations between prior to and just posttransport (T0) was less pronounced in calves transported for 6 h (746.1 µmol/L and 0.38 mmol/L, respectively) than in calves transported for 18 h (850.6 µmol/L and 0.50 mmol/L). Overall, the recovery rate of calves at the veal farm seemed rapid; all blood parameters returned to (below) pretransport values within 48 h posttransport. We concluded that feeding milk before short-term transport helps young veal calves cope with transport, whereas this is not the case during long-term transport.

Whole blood transcriptomic analysis of beef cattle at arrival identifies potential predictive molecules and mechanisms that indicate animals that naturally resist bovine respiratory disease

Bovine respiratory disease (BRD) is a multifactorial disease complex and the leading infectious disease in post-weaned beef cattle. Clinical manifestations of BRD are recognized in beef calves within a high-risk setting, commonly associated with weaning, shipping, and novel feeding and housing environments. However, the understanding of complex host immune interactions and genomic mechanisms involved in BRD susceptibility remain elusive. Utilizing high-throughput RNA-sequencing, we contrasted the at-arrival blood transcriptomes of 6 beef cattle that ultimately developed BRD against 5 beef cattle that remained healthy within the same herd, differentiating BRD diagnosis from production metadata and treatment records. We identified 135 differentially expressed genes (DEGs) using the differential gene expression tools edgeR and DESeq2. Thirty-six of the DEGs shared between these two analysis platforms were prioritized for investigation of their relevance to infectious disease resistance using WebGestalt, STRING, and Reactome. Biological processes related to inflammatory response, immunological defense, lipoxin metabolism, and macrophage function were identified. Production of specialized pro-resolvin mediators (SPMs) and endogenous metabolism of angiotensinogen were increased in animals that resisted BRD. Protein-protein interaction modeling of gene products with significantly higher expression in cattle that naturally acquire BRD identified molecular processes involving microbial killing. Accordingly, identification of DEGs in whole blood at arrival revealed a clear distinction between calves that went on to develop BRD and those that resisted BRD. These results provide novel insight into host immune factors that are present at the time of arrival that confer protection from BRD.

Pig trade networks through live pig markets in Guangdong Province, China

This study used social network analysis to investigate the indirect contact network between counties through the movement of live pigs through four wholesale live pig markets in Guangdong Province, China. All 14,118 trade records for January and June 2016 were collected from the markets and the patterns of pig trade in these markets analysed. Maps were developed to show the movement pathways. Evaluating the network between source counties was the primary objective of this study. A 1‐mode network was developed. Characteristics of the trading network were explored, and the degree, betweenness and closeness were calculated for each source county. Models were developed to compare the impacts of different disease control strategies on the potential magnitude of an epidemic spreading through this network. The results show that pigs from 151 counties were delivered to the four wholesale live pig markets in January and/or June 2016. More batches (truckloads of pigs sourced from one or more piggeries) were traded in these markets in January (8,001) than in June 2016 (6,117). The pigs were predominantly sourced from counties inside Guangdong Province (90%), along with counties in Hunan, Guangxi, Jiangxi, Fujian and Henan provinces. The major source counties (46 in total) contributed 94% of the total batches during the two‐month study period. Pigs were sourced from piggeries located 10 to 1,417 km from the markets. The distribution of the nodes' degrees in both January and June indicates a free‐scale network property, and the network in January had a higher clustering coefficient (0.54 vs. 0.39) and a shorter average pathway length (1.91 vs. 2.06) than that in June. The most connected counties of the network were in the central, northern and western regions of Guangdong Province. Compared with randomly removing counties from the network, eliminating counties with higher betweenness, degree or closeness resulted in a greater reduction of the magnitude of a potential epidemic. The findings of this study can be used to inform targeted control interventions for disease spread through this live pig market trade network in south China.

Prevalence of Pathogens Related to Bovine Respiratory Disease Before and After Transportation in Beef Steers: Preliminary Results

Simple Summary

Bovine respiratory disease (BRD) affects the lower respiratory tract of cattle, causing high mortality. The syndrome has a multifactorial etiology and transport seems to favor pathogen proliferation. This study investigated the prevalence of different pathogens involved in BRD, in the nasal microbiota of beef steers collected before and after a long-distance journey. A total of 56 Limousine animals were included, travelling in three different shipments, on the same route from France to southern Italy in a semitrailer, on three different days from February to April. Prior to shipment (T0) and four days after arrival (T1), two deep nasopharyngeal swabs (DNS)/steer were collected and tested by bimolecular analysis. Neither bovine viral diarrhea virus (BVDV) nor bovine herpesvirus type 1 (BoHV-1) were detected. A higher prevalence of Histophilus somni was observed in the DNS collected during the third shipment in comparison with those registered during the first and the second one, probably due to a higher prevalence at departure. Conversely, the prevalence of bovine coronavirus, bovine respiratory syncytial virus, Mannheimia haemolytica, Mycoplasma bovis and Pasteurella multocida was higher on arrival in comparison with departure, confirming data reported in the literature. Overall, there were nasal microbiota changes in beef steers, with an increase in the prevalence of pathogens associated with BRD after travelling.

Abstract

Bovine respiratory disease (BRD) is a serious health and economic problem in the beef industry, which is often associated with transportation and caused by different pathogens. The prevalence of bovine herpesvirus type 1 (BoHV-1), bovine adenovirus (BAdV), bovine viral diarrhea virus (BVDV), bovine coronavirus (BCoV), bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus (BPiV), Pasteurella multocida, Mannheimia haemolytica, Histophilus somni, Mycoplasma bovis, in the nasal microbiota of beef steers before and after the same long-distance journey from France to southern Italy was documented. Fifty-six Limousine animals of three different shipments, travelling on three different days from February to April, were included. Prior to shipment (T0) and four days after arrival (T1), two DNS/animal were collected and tested by Real Time quantitative PCR (qPCR). Univariate logistic regression was carried out, considering time and day as fixed factors and the outcome of qPCR for each pathogen as a dependent categorical dichotomous variable (positive/negative, 1/0). The fact that the number of H. somni positive animals were found to be higher in the third shipment than the first and second one, indicating that this pathogen was already present before loading, is relevant. The prevalence of BCoV, BRSV, M. haemolytica, M. bovis, P. multocida was higher at T1 than T0, suggesting that other factors, such as stress and the epidemiological status of the arrival farm, played a role. The tested animals were not treated before and after transport, and our results are in agreement with the current literature, supporting the hypothesis that the prevalence of pathogens related to BRD would increase after travelling, with an increased risk of pathogens shedding.

The effect of calf jackets on the health, performance, and skin temperature of dairy origin beef calves

Variations and extremities in climatic conditions can result in cold stress for dairy calves during the preweaning period. The objective of this study was to investigate the effect of calf jackets on the health, performance, and skin temperature of dairy-origin beef calves. This study took place in a designated calf rearing unit, spanned for a duration of 1 yr, and consisted of five batches of calves. Calves (30.9 ± 1.68 d of age; 55.9 ± 0.20 kg live weight) were assigned to one of four treatment groups on arrival at the rearing unit. Treatments consisted of control (no jacket), arrival (jacket for 2 wk postarrival), weight (jacket for a minimum of 2 wk and until 65 kg live weight), and wean (jacket until 5 d postweaning). Ambient conditions differed significantly (P < 0.001) during each of the five batches; batch 4 was the coldest with a mean ambient temperature of 6.16 °C. Significant differences were observed between the five batches for day 50 weight (P < 0.01) and disease incidence (P < 0.05). However, treatment had no significant effect on calf health or performance (P > 0.05) during any of the five batches. Skin temperature was significantly greater (P < 0.001) for calves wearing a jacket. Furthermore, there was a significant (P < 0.001) relationship between ambient temperature-humidity index and skin temperature for calves with and without a calf jacket. Therefore, although calf jackets had no benefit in terms of health or performance, they did act as a barrier to environmental conditions.

Revisiting Oxidative Stress and the Use of Organic Selenium in Dairy Cow Nutrition

In commercial animals production, productive stress can negatively impact health status and subsequent productive and reproductive performance. A great body of evidence has demonstrated that as a consequence of productive stress, an overproduction of free radicals, disturbance of redox balance/signaling, and oxidative stress were observed. There is a range of antioxidants that can be supplied with animal feed to help build and maintain the antioxidant defense system of the body responsible for prevention of the damaging effects of free radicals and the toxic products of their metabolism. Among feed-derived antioxidants, selenium (Se) was shown to have a special place as an essential part of 25 selenoproteins identified in animals. There is a comprehensive body of research in monogastric species that clearly shows that Se bioavailability within the diet is very much dependent on the form of the element used. Organic Se, in the form of selenomethionine (SeMet), has been reported to be a much more effective Se source when compared with mineral forms such as sodium selenite or selenate. It has been proposed that one of the main advantages of organic Se in pig and poultry nutrition is the non-specific incorporation of SeMet into general body proteins, thus forming an endogenous Se reserve that can be utilized during periods of stress for additional synthesis of selenoproteins. Responses in ruminant species to supplementary Se tend to be much more variable than those reported in monogastric species, and much of this variability may be a consequence of the different fates of Se forms in the rumen following ingestion. It is likely that the reducing conditions found in the rumen are responsible for the markedly lower assimilation of inorganic forms of Se, thus predisposing selenite-fed animals to potential Se inadequacy that may in turn compromise animal health and production. A growing body of evidence demonstrates that organic Se has a number of benefits, particularly in dairy and beef animals; these include improved Se and antioxidant status and better Se transfer via the placenta, colostrum, and milk to the newborn. However, there is a paucity in the data concerning molecular mechanisms of SeMet assimilation, metabolism and selenoprotein synthesis regulation in ruminant animals, and as such, further investigation is required.