Blood serum transferrin concentration in cattle in various physiological states, in veal calves fed different amounts of iron, and in cattle affected by infectious and non-infectious diseases

Host Serum Proteins as Potential Biomarkers of Bovine Tuberculosis Resistance Phenotype

Eradication of bovine tuberculosis (bTB) continues to be a worldwide challenge. The lack of reliable vaccines dampens the control and eradication programs of Mycobacterium bovis infection and spread. Selection and breeding of cattle resistant to M. bovis infection would greatly enhance the effectiveness of bTB eradication programs. Here, we have evaluated the potential of serum proteins as biomarkers of cattle resistance to bTB in Holstein-Friesian cows, 6-8-year-old, born and raised in similar conditions in herds with bTB prevalence >30%. Serum proteins obtained from uninfected cows (bTB-resistant; R) were compared to those from infected cows (bTB-susceptible; S), defined by a negative or positive bTB diagnosis, respectively. bTB diagnosis included: (i) single intradermal (caudal fold) tuberculin test, (ii) whole blood IFN-gamma test, (iii) gross visible lesions in lymph nodes and lungs by inspection at the abattoir, and (iv) a bacteriological culture for M. bovis. Using 2D-GE and LC-ESI-MS/MS, we found higher expression levels of primary amine oxidase (AO), complement component 5 (C5), and serotransferrin (TF) in R cattle than S cattle. In-house developed and standardized ELISAs for these novel biomarkers showed the best sensitivities of 72, 77, 77%, and specificities of 94, 94, 83%, for AO, C5, and TF, respectively. AUC-ROC (95% CI) values of 0.8935 (0.7906-0.9964), 0.9290 (0.8484-1.010), and 0.8580 (0.7291-0.9869) were obtained at cut-off points of 192.0, 176.5 ng/ml, and 2.1 mg/ml for AO, C5, and TF, respectively. These proteins are involved in inflammatory/immunomodulatory responses to infections and may provide a novel avenue of research to determine the mechanisms of protection against bTB. Overall, our results indicate that these proteins could be novel biomarkers to help identify cattle resistant to bTB, which in turn could be used to strengthen the effectiveness of existing eradication programs against bTB.

The Electrophoretic Pattern of Serum Proteins in Sheep with Naturally Acquired Gastrointestinal Nematode Infections

The objective of this study was to describe the serum protein pattern in sheep with naturally acquired gastrointestinal parasitosis and to compare the distribution of protein fractions with the results obtained in animals with negative fecal examination results. Fecal and blood samples were taken from twenty-nine sheep positive for nematode eggs and twenty-four animals with negative results of fecal examination. Between the evaluated groups of sheep significant differences were noted in the relative mean values for all protein fractions and for albumin/globulin ratio (p<0.01 and p<0.001). The concentrations of total proteins showed no significant differences between both groups of sheep. The absolute mean values of albumin, α2-globulins and A/G ratio were significantly lower, the mean concentrations of α1-, β-, γ1- and γ2-globulins significantly higher in the nematode positive group of sheep (p<0.01 and p<0.001). In the nematode positive group the protein electrophoretic pattern showed a double α2-zone in three sheep and the γ-globulin zones were characterized by a diffuse higher broad and wide peaks. The presented results indicate that the gastrointestinal parasitic infections in sheep alter the distribution of serum proteins, and suggest their usefulness in animals with unchanged serum protein concentrations. The study brings new findings and extends the knowledge about the metabolic responses and consequences of gastrointestinal parasitic infections in sheep, particularly with regard to alterations in protein metabolism.

Hydrolyzed Yeast Supplementation in Calf Starter Promotes Innate Immune Responses in Holstein Calves under Weaning Stress Condition

Simple Summary

New-born Holstein calves are vulnerable to infectious diseases owing to incomplete immune system development. This study aimed to evaluate the effects of six weeks of hydrolyzed yeast supplementation in Holstein calf starter on stress and immune responses after weaning. Hydrolyzed yeast supplementation facilitated the innate immune response after weaning, with a limited stress response. Therefore, the supplementation of hydrolyzed yeast in calf starters may help weaned calves adapt to diet-induced stresses. These results suggest that hydrolyzed yeast may be an effective feed additive for modulating stress-related immune responses.

Abstract

Weaned calves are susceptible to infectious diseases because of the stress and malnutrition that occurs during weaning. Therefore, the dairy industry requires effective feed additives to ameliorate stress responses and promote immunity. This study aimed to investigate the effects of hydrolyzed yeast (HY) supplementation on the growth performance, immune and stress parameters, and health status of calves after weaning. Eighteen Holstein calves were randomly assigned to two groups, either receiving a control calf starter or 0.2% HY calf starter from one week of age. All calves were weaned at six weeks of age as a stress challenge. The HY-fed calves had a significantly-higher body weight gain during the post-weaning period (kg/week) compared to the control. Cortisol levels at three days post-weaning (DPW) were significantly lower in the HY group than the control group. Calves fed HY had significantly-higher serum levels of tumor necrosis factor-α and interleukin-1β at one DPW. The HY-fed calves also had higher concentrations of the acute-phase proteins, haptoglobin, serum amyloid A, and transferrin at one DPW. In addition, the diarrhea severity in HY-fed calves was milder after weaning compared to the control group. Our results indicate that HY supplementation reduces stress responses and may promote innate immunity in newly-weaned calves.

Serum iron concentration is a useful biomarker for assessing the level of inflammation that causes systemic symptoms in bovine acute mastitis similar to plasma haptoglobin

The aim of present study was to evaluate the precision of plasma haptoglobin (HPT), serum iron (Fe) and plasma transferrin (Tf) concentrations as biomarkers of the severity of acute mastitis (AM) in cows. Fourteen Holstein Friesian cows with AM were divided into severe (n=8) and mild groups (n=6) based on systemic and local inflammation, and 12 healthy cows were also enrolled as controls. As a result, significant changes were observed in plasma HPT and serum Fe concentrations. The proposed cut-off points for plasma HPT and serum Fe concentrations for the severity of AM in cows based on receiver operating characteristic analyses were >10.3 µg/ml and <49.0 µg/dl, respectively. No significant difference was observed in the plasma Tf concentration.

Transferrin Binding Protein B and Transferrin Binding Protein A2 Expand the Transferrin Recognition Range of Histophilus somni

The bacterial bipartite transferrin receptor is an iron acquisition system that several important human and animal pathogens require for survival. It consists of the TonB-dependent transporter transferrin binding protein A (TbpA) and the surface lipoprotein transferrin binding protein B (TbpB). Curiously, the Tbps are only found in host-specific pathogens and are themselves host specific, meaning that they will bind to the transferrin of their host species but not to the transferrins of other animal species. While this phenomenon has long been established, neither the steps in the evolutionary process that led to this exquisite adaptation for the host nor the steps that could alter it are known. We sought to gain insight into these processes by studying Tbp specificity in Histophilus somni, an economically important pathogen of cattle. A past study showed that whole cells of H. somni specifically bind bovine transferrin but not transferrin from sheep and goats, two bovids whose transferrins share 93% amino acid sequence identity with bovine transferrin. To our surprise, we found that H. somni can use sheep and goat transferrins as iron sources for growth and that HsTbpB, but not HsTbpA, has detectable affinity for sheep and goat transferrins. Furthermore, a third transferrin binding protein found in H. somni, HsTbpA2, also showed affinity for sheep and goat transferrins. Our results suggest that H. somni TbpB and TbpA2 may contribute to broadening the host transferrin recognition range of H. somni IMPORTANCE Host-restricted pathogens infect a single host species or a narrow range of host species. Histophilus somni, a pathogen that incurs severe economic losses for the cattle industry, infects cattle, sheep, and goats but not other mammals. The transferrin binding proteins, TbpA and TbpB, are thought to be a key iron acquisition system in H. somni; however, despite their importance, H. somni TbpA and TbpB were previously shown to be cattle transferrin specific. In our study, we find that H. somni TbpB and another little-studied Tbp, TbpA2, bind sheep and goat transferrins, as well as bovine transferrin. Our results suggest that TbpB and TbpA2 may allow for host range expansion and provide a mechanism for how host specificity in Tbp-encoding pathogens can be altered.

Clinical Chemistry Investigations in Recumbent and Healthy German Holstein Cows After the Fifth Day in Milk

Introduction

Recumbency is a frequent symptom occurring throughout lactation. Its cause can be related to the energy or mineral metabolism, or to trauma or infectious diseases. We compared various clinical chemistry parameters between healthy and recumbent cows and between cows with different causes of recumbency and determined if hypocalcaemia manifests in later lactation.

Material and Methods

Recumbent (n = 32) and healthy (n = 32) German Holstein cows were studied. After clinical examination, a serum sample was taken to measure the concentrations of Mg, Ca, Fe, Na, K, Pi, β-hydroxybutyrate, total bilirubin, non-esterified fatty acids (NEFA), urea, and creatinine as well as activities of alkaline phosphatase, aspartate aminotransferase (AST), creatine kinase (CK), and γ-glutamyl transferase in recumbent cows > 5 d in milk and control cows matched for age, lactation number, and pregnancy stage.

Results

In recumbent cows, mean serum concentrations of NEFA, bilirubin, and CK were statistically higher, while those of Fe, K, and Pi were significantly lower. Parameters compared between different recumbency diagnoses showed some descriptive Fe, K, urea, and AST differences, but these were not statistically significant.

Conclusion

The results show that only a limited number of parameters have diagnostic besides therapeutic value. Although of minor importance in our study, hypocalcaemia should be considered a cause of recumbency, even outside the typical risk period of parturient paresis.

The concentrations of selected blood serum proteins in calves during the first three months of life

This study was aimed at the evaluation of changes in the concentrations of selected blood serum proteins in calves during the first three months of life, including precolostral, colostral, milk, transitional and solid feeding period. Nine clinically healthy calves were used in this study. The first blood sampling was performed before the colostrum intake (day 0) and then at 1, 2, 7, 14, 30, 60, and 90 days of age. Blood serum was analyzed for the concentrations of α1-fetoprotein, prealbumin, transferrin, and lactoferrin. The results showed significant changes in the serum concentrations of all the evaluated proteins in calves during the first three months of life (P< 0.01 andP< 0.001). At birth, the mean concentration of α1-fetoprotein was low and increased more than × 8 at one day after colostrum intake, then a gradual decrease was found up to day 30 of life. Similar tendency was observed in the concentrations of prealbumin and lactoferrin. While the concentrations of prealbumin increased approximately × 3.5 at one day after colostrum intake, the serum lactoferrin values showed approximately 1.5-fold increase. A subsequent gradual decrease from the 2ndday of life was found for both prealbumin and lactoferrin. In the concentrations of transferrin, a significant increase was observed on day 7 (P< 0.05). The highest values were found at the age of 14 and 30 days. These results suggest that concentrations of these proteins in calves are markedly altered during the postnatal period, which should be taken into consideration for their precise interpretation in young animals.

Proteomic analysis of plasma from Holstein cows testing positive for Mycobacterium avium subsp. paratuberculosis (MAP)

Johne's disease (JD) is a widespread and economically important chronic inflammatory disease of the small intestine of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). Although there are several techniques available for diagnosis of JD, their sensitivity is questionable. New proteome profiling methods, such as serum/plasma protein fingerprinting by 2-Dimensional Fluorescence Difference Gel Electrophoresis (2D-DIGE), may therefore be useful for identifying novel protein biomarkers of MAP infection. In this study, plasma samples were collected from 380 Holstein cows and screened for the presence of MAP infection using the M.pt. Johne's antibody Kit (IDEXX). Five negative (MAP-), and 5 strongly positive (MAP+) cows were selected for proteomic analysis. Highly abundant proteins were depleted from the plasma samples using the ProteoMiner technology (Bio-Rad) to enhance the resolution of low abundance proteins. Plasma samples from MAP-, MAP+, and a pooled internal control were labelled with different fluorescent dyes and separated based on their isoelectrical point (IP) and then their molecular weight. Gel images of the fluorescent plasma protein maps were acquired using a Typhoon scanner and analyzed using the DeCyder software. Proteins that were differentially expressed were excised from the gels, trypsin digested, and subjected to MS/MS analysis for identification. Six proteins were identified as being up-regulated at least 2-fold in MAP+ cows including: transferrin, gelsolin isoforms α & β (actin binding protein - ABP), complement subcomponent C1r, complement component C3, amine oxidase - copper containing 3 (AOC3), and coagulation factor II (thrombin) (p<0.05). Two proteins that were down-regulated approximately 2-fold in the MAP+ cows included coagulation factor XIII -B polypeptide (COAFXIII), and fibrinogen γ chain (FGG) and its precursor.

Acute Phase Proteins in Experimentally Induced Pregnancy Toxemia in Goats

The present work aimed to study the behavior of acute phase proteins (haptoglobin, serum amyloid A, acid soluble glycoprotein, fibrinogen, and albumin) in fasting-induced pregnancy toxemia in goats and their relationship with classical indicators of this disorder such as beta-hydroxybutyrate and nonesterified fatty acids in the blood and decreased urine pH and ketonuria. Twelve adult Murciano–Granadina goats at the final stage of gestation were used in this experiment. Pregnancy toxemia was induced in 6 goats by fasting for 72 hr. The other 6 animals were used as control group. Ketonuria was present in 4 out of 5 fasting animals at 24 hr and in all fasting animals at 48 hr of fasting. Serum nonesterified fatty acids were significantly increased at 24, 48, and 72 hr of fasting. Beta-hydroxybutyrate and haptoglobin achieved significantly increased concentrations at 48 hr and 72 hr, respectively, remaining increased during the entire study. Serum amyloid A, acid soluble glycoprotein, fibrinogen, and albumin were not affected by fasting. In conclusion, acute phase proteins (including haptoglobin) seemed not to have an advantage over traditional markers in diagnosis of fasting-induced pregnancy toxemia in goats.

Proteinograma sérico de bovinos da raça Curraleir

Estudou-se o perfil eletroforético das proteínas séricas de bovinos sadios da raça Curraleiro por meio da técnica de eletroforese em gel de acrilamida contendo dodecil sulfato de sódio. Utilizaram-se amostras de soro sanguíneo de 228 bovinos da raça Curraleiro, 51 machos e 177 fêmeas, com idades entre sete meses e 12 anos, pertencentes a dois rebanhos localizados nos Estados de Goiás e Tocantins. Foram quantificadas proteína total e concentração plasmática de fibrinogênio. Verificaram-se variações nas concentrações das diferentes frações proteicas. Foram detectadas 26 proteínas e identificadas 10 delas. A ceruloplasmina esteve ausente em 78,1% dos indivíduos, e a α-antitripsina não foi detectada em nenhum animal. Proteína total, globulina, IgA, IgG e fibrinogênio aumentaram com a idade e houve correlação positiva entre os níveis séricos de haptoglobina e α1-glicoproteína ácida.

Discovery and validation of serum biomarkers expressed over the first twelve weeks of Fasciola hepatica infection in sheep

Serum biomarkers associated with Fasciola hepatica infection of Corriedale sheep were analysed during the first 12 weeks of infection using surface-enhanced laser desorption ionisation time of flight mass spectrometry (SELDI-TOF MS). In the discovery phase of analysis, pooled sera collected at week 0 and at each week p.i. to week 12 were fractionated by anion-exchange chromatography and the protein mass fingerprints obtained in individual fractions were in the M/z range 1.5-150 kDa. A total of 2302 protein clusters (peaks) were identified that varied between time-points following infection with peaks increasing or decreasing in intensity, or showing transient variation in intensity, during the 12 weeks of parasite challenge. In the validation phase, candidate biomarkers in sera of individual sheep at weeks 3 and 9 p.i. were analysed, identifying 100 protein peaks, many of which are small peptides <10 kDa in size: 54% of these peaks were up-regulated in intensity at week 3 or 9 p.i. Twenty-six biomarkers were chosen for further study, ranging in size from 1832 to 89,823 Da: six biomarkers were up-regulated at weeks 3 and 9 p.i., 16 biomarkers were up-regulated only at week 9 p.i. and four biomarkers were down-regulated at week 9 p.i. Two biomarkers up-regulated at week 9 were identified as transferrin (77.2 kDa) and Apolipoprotein A-IV (44.3 kDa), respectively. The results show that the interaction between the host and F. hepatica is complex, with changes in biomarker patterns beginning within 3 weeks of infection and either persisting to weeks 9-12 or showing transient changes during infection. Identification of biomarkers expressed during ovine fasciolosis may provide insights into mechanisms of pathogenesis and immunity to Fasciola and may assist in the rational development and delivery of vaccines.

Iron modulates the replication of virulent Mycobacterium bovis in resting and activated bovine and possum macrophages

Bovine and possum macrophages were infected in vitro with a virulent strain of Mycobacterium bovis, and mycobacterial replication was measured in the infected macrophages cultured under a variety of conditions. Virulent M. bovis replicated substantially in alveolar possum macrophages as well as in bovine blood monocyte-derived macrophages. Addition of recombinant bovine interferon-gamma (IFN-gamma) with low concentrations of lipopolysaccharide (LPS) rendered bovine macrophages significantly more resistant to M. bovis replication. Disruption of iron levels in infected macrophages by addition of apotransferrin or bovine lactoferrin blocked replication of M. bovis in both bovine and possum macrophages. On the other hand, addition of exogenous iron, either in the form of iron citrate or iron-saturated transferrin, rendered macrophages of both species much more permissive for the replication of M. bovis. The impact of iron deprivation/loading on the mycobacteriostatic activity of cells was independent of nitric-oxide release, as well as independent of the generation of oxygen radical species in both possum and bovine macrophages. Exogenous iron was shown to reverse the ability of IFN-gamma/LPS pulsed bovine macrophages to restrict M. bovis replication. When autologous possum lymphocytes from animals vaccinated with M. bovis strain BCG were added to infected macrophages, they rendered the macrophages less permissive for virulent M. bovis replication. Loading the cells with iron prior to this macrophage-lymphocyte interaction, reversed this immune effect induced by sensitized cells. We conclude that, in two important animal species, intracellular iron level plays an important role in M. bovis replication in macrophages, irrespective of their activation status.

Current research on acute phase proteins in veterinary diagnosis: an overview

The acute phase proteins (APP) are a group of blood proteins that contribute to restoring homeostasis and limiting microbial growth in an antibody-independent manner in animals subjected to infection, inflammation, surgical trauma or stress. In the last two decades, many advances have been made in monitoring APP in both farm and companion animals for clinical and experimental purposes. Also, the mechanism of the APP response is receiving attention in veterinary science in connection with the innate immune systems of animals. This review describes the results of recent research on animal APP, with special reference to their induction and regulatory mechanisms, their biological functions, and their current and future applications to veterinary diagnosis and animal production.

Bovine serum transferrin concentration during acute infection with Haemophilus somnus

A novel, competitive immunoassay based on time-resolved fluorimetry was developed, and used to measure the serum concentration of bovine transferrin during acute Haemophilus somnus pneumonia. Upper and lower limits of normality were established using serum from healthy cattle (3.72-1.37 mgmL-1). Following experimental infection with Haemophilus somnus, transferrin concentration was depressed in all calves but recovered to pre-infection levels in groups of calves which had either no lesions, or mild lesions at necropsy between 5 and 6 days after infection. In a third group, which developed extensive lesions, the transferrin concentration remained depressed. Transferrin levels remained within the normal range for all calves during the experimental period. Those calves which had low transferrin concentrations pre-infection, developed extensive lung lesions following experimental infection with Haemophilus somnus.

Metabolic, endocrine and haematological responses to intravenous E. coli endotoxin administration in 1-week-old calves

Responses to i.v. injected E. coli endotoxin (E), followed by saline infusion, as compared with saline infusion alone, were studied for 24 h in 1-week-old calves. After administration of E, respiratory rate (RR), heart rate (HR), rectal temperature (RT), serum iron, insulin, (I), cortisol and tumor necrosis factor-alpha, transiently, and urea, continuously, increased. Isoleucine and leucine became elevated at 24 h, whereas white-blood-cell number, free fatty acids (FFA) and triglycerides (TG) increased after an initial fall. After administration of E, packed-cell volume, erythrocyte number, haemoglobin, glucose (G), cholesterol, phospholipids (PL), lysine, arginine, proline, citrulline, calcium (Ca), inorganic phosphorus, insulin-like growth factor I (IGF-I) and 3,5,3'-triiodothyronine (T3) concentrations and alkaline phosphatase (AP) and gamma-glutamyl transferase (gamma GT) activities increased significantly while growth hormone decreased non-significantly. When saline was infused alone, G, TG, PL, Ca, AP, gamma GT, I, IGF-I and T3 decreased, while FFA, urea and sodium increased, but, changes of G, urea, AP, IGF-I and T3 were less marked than after injection of E. Potassium, total protein and albumin concentrations, and glutamyl dehydrogenase and glutamate oxalacetate transaminase activities were not significantly affected by either treatment. In conclusion, metabolic and endocrine changes during saline infusion alone were typical for food withdrawal. Changes of variables after administration of E were transient, biphasic or sustained, thus expressing complex interactions between metabolic parameters, endocrine factors and cytokines.

Effects of growth hormone on growth performance, haematology, metabolites and hormones in iron-deficient veal calves

Effects of subcutaneous (s.c.) administration of 50 micrograms/kg body weight of recombinant bovine growth hormone (rbGH) or saline were studied for 11 weeks in 40 intact male veal calves supplied 50 mg or 10 mg of iron (Fe)/kg of milk replacer (MR). Feed intake, average daily gain and growth: feed ratio were reduced in Fe-deficient calves, but not significantly influenced by rbGH. Plasma Fe and haemoglobin concentration, red-cell number and packed cell volume were decreased in Fe-deficient calves (P < 0.05) and rbGH further reduced red-cell number in Fe-deficient calves (P < 0.05). The age-dependent increase of total Fe binding capacity was greater in Fe-deficient calves and enhanced by rbGH (P < 0.05). Plasma urea concentrations increased, whereas glucose (G) and triiodothyronine (T3) levels decreased in Fe-deficient calves. rbGH significantly increased G in calves fed MR containing 50 mg/kg (P < 0.05) and influenced urea concentrations (P < 0.05). Plasma insulin (I) and IGF-I concentrations were lower in Fe-deficient calves (P < 0.05). Plasma GH in the first hours after rbGH injections increased (P < 0.05) to higher levels in calves fed 10 than in those fed 50 mg Fe/kg MR, but incremental changes were comparable. In conclusion, low Fe intake caused haematologic, metabolic and endocrine changes. Plasma IGF-I, I and T3 concentrations after rbGH administration and effects of rbGH on IGF-I in Fe-deficient calves were reduced, even though plasma GH levels were increased.

Iron status, erythropoiesis, meat colour, health status and growth performance of veal calves held on and fed straw

Two experiments were designed to study the iron (Fe) status in veal calves (62 intact males) fed and held on straw. In experiment 1, two groups were fed 20 mg Fe/kg milk replacer (MR) and held unattached on rye or barley straw litter. In experiment 2, groups were fed 20 mg Fe/kg MR and held unattached on rye straw litter or on sawdust or attached on wooden slatted floors without straw litter or were fed 50 mg Fe/kg MR and held unattached on sawdust. Fe concentrations in tested straw sorts (rye, barley, wheat, triticale) were similar and ranged from 15 to 85 mg Fe/kg dry matter. Growth performance and health status were not significantly influenced by Fe intake through MR or straw. Straw intake in the group fed straw was greater (P < 0.01) at the end than at the start of the growth period, but intake of different straw sorts was similar. Calves fed 20, but not those fed 50 mg Fe/kg MR, developed marked hypoferraemia, but only moderate anaemia. Total iron binding capacity (TIBC) was significantly (P < 0.05) and transferrin (Tf) concentration was numerically higher in calves fed 20 than in those fed 50 mg Fe/kg MR on slaughter day. TIBC and Tf were positively correlated (r = 0.63). Haemin concentration and lightness of m. rectus abdominis were significantly (P < 0.01), whereas myoglobin concentration was numerically greater in calves fed 50 than in those fed 20 mg Fe/kg MR. In conclusion, haematological and blood chemical parameters and meat colour were influenced only by high Fe intake through MR, but not if calves were held on straw litter or were fed straw.