Immunity In Calves Research Articles

Early-life Clostridium butyricum supplementation improved rumen development and immune by promoting the maturation of intestinal microbiota

This study evaluated the effects of Clostridium butyricum supplementation on rumen fermentation, serum immunoglobulins, and fecal microbiota in dairy calves. Seventy-five 3-days-age calves were divided into five groups (n = 15 per group) receiving 0, 0.2, 0.4, 0.8, and 1.6 g/day of C. butyricum freeze-dried powder (10ˆ10 CFU/g) in milk replacer. Rumen fluid and blood samples were collected at various intervals, and fecal samples from eight calves per group were collected at 3, 28, and 42 days. C. butyricum supplementation showed a negative correlation with rumen pH (P = 0.032) and positive correlations with acetate/propionate (P = 0.007) and acetate + butyrate/propionate (P = 0.022). It had quadratic effects on rumen acetate (P = 0.029) and isobutyrate (P = 0.021). IgA concentration increased with dose (P = 0.002), and dose-time interactions affected serum IgM (P = 0.013) and IgG (P < 0.001). C. butyricum did not influence fecal microbiota diversity but increased the abundance of Helicobacter japonicus, Weissella viridescens, Leuconostoc mesenteroides, Leuconostoc citreum, while negatively correlating with Streptococcus hyointestinalis (P < 0.05). Microbiota functions related to galactose metabolism, and fatty acid degradation decreased with age (P < 0.05), while fatty acid biosynthesis and glycolysis/gluconeogenesis increased (P < 0.05). L. mesenteroides, and L. citreum, and negatively correlated with galactose metabolism and fatty acid degradation but positively with fatty acid biosynthesis (P < 0.01). C. butyricum supplementation variably impacted rumen pH, acetate/propionate, and acetate + butyrate/propionate, particularly on day 42 versus day 60, affecting acetate, butyrate, and isovalerate differently over time. Our findings suggest that early-life C. butyricum supplementation may promote the maturation of immunity and intestinal microbiota of pre-weaning dairy calves, the optimal dose was 0.8 to 1.6 x 10ˆ10 CFU/d.

Growth Promotion and Economic Benefits of the Probiotic Lactiplantibacillus plantarum in Calves

Objectives: Various measures have been attempted to prevent infectious diseases in calves, such as environmental improvement and vaccine administration. Probiotics are commonly used to improve the body condition of newborn calves and prevent disease. In our previous research, Lactiplantibacillus plantarum RGU-LP1 (LP1) suppressed the expression of inflammatory cytokines in PBMCs of cattle fed it in the diet. In this study, we evaluated the effect of LP1 on the weights and number of treatments of the calves. Methods: Twenty-six one-week-old Holstein bull calves were divided into two groups (thirteen each), the LP1 group (LP1-treated) and the CN group (no LP1 fed), and tested as follows. The LP1 group was fed lyophilized LP1 (109 CFU/head/day) in milk replacer for 40 days. The CN group was fed the same diet only. Calves were followed for 63 days. The average treatment costs for the LP1 during the period were recorded. Feces and blood were collected from each calf during this period. Feces were examined for gut microbiota, and blood for immune assay and cytokine gene expression. Results: The LP1-treated group showed a decrease in disease incidence and an increase in body weights compared to controls. The average treatment cost during the observation period was significantly reduced compared to the CN group. The expression of TGFβ and IL10, inhibitory cytokines of inflammation, was significantly increased. The simultaneous expression of this set of inhibitory molecules resulted in low serum IL1β levels during the growth period. Conclusions: The Th1-type cytokine IFNγ was also significantly increased in LP1-treated calves. By reducing the amount of disease treatments and increasing dairy gain, LP1 is effective in preventing infectious diseases in calves. In addition, the increase in IFNγ by LP1 indicates improved Th1-type immunity in calves. These results show that LP1 has effects on the regulated inflammatory response and growth of calves.

Lactation stage-specific variations in health and lipid-associated milk fat globule membrane proteins in Holstein Friesian cow and Murrah buffalo

Bovine milk fat globule membrane (MFGM) proteins are crucial to calf health and human nutrition, but a knowledge gap exists for its lactation stage-specific variations in cows and buffaloes. This study employed mass spectrometry to identify the inter- and intra-lactation stage-specific MFGM proteins in Murrah buffalo (Mu) and Holstein Friesian cow (HF). Mu exhibited higher proteins (n=264) than HF (n=250); utilizing multivariate analysis, differentially abundant proteins (n=78 in HF, n=31 in Mu) were identified specific to lactation stages. The MFGM proteins were categorized into health-associated (47.1%), lipid-associated proteins (44.1%), and shared proteins (8.8%). HF milk contained all health-associated proteins detected in Mu, besides possessing unique proteins (e.g., BTN1A1, SAA3, and ENPP3), including lipid-associated proteins that contributed to improved calf immunity. These results suggest HF milk is more suitable for calf health and dairy product development, including expanding our understanding of lactation stage-specific MFGM proteins and highlighting their potential health benefits.

Effect of betaine supplementation on immunity, energy, and lipid metabolites of growing Murrah buffalo calves

This study aimed to observe the effect of betaine (BET) supplementation on the growth, immunity, energy, and lipid metabolites of Murrah buffalo calves. Twenty-one Murrah buffalo calves were taken and randomly distributed into three groups (n=3) after blocking by body weight (98.70±1.31 kg) and age (8.12±0.55 months). The feeding regimen was the same in all the groups except that the Treatment groups were supplemented additionally with 0.0 (B0), 7.0 (B7), and 14.0 (B14) g/d BET in three respective groups for 90 d of the experiment period. Total leukocytes (TLC), neutrophils, lymphocytes, total immunoglobulin (TIG), total antioxidant activity (TAA), energy, and lipid metabolites were observed at fortnightly intervals during 90 d experimental periods. Adding BET up to 14 g/d did not exert (P&gt;0.05) any effect on total leukocytes and neutrophils concentration. Lymphocytes, TIG, and TAA were increased significantly (P&lt;0.05) in BET received groups either dose 7 or 14 g/d than in the control. No effect of dietary addition of BET was observed on the glucose, non-esterifies fatty acid (NEFA), total cholesterol (TCH), and high-density lipoprotein cholesterol (HDL-CH). The results of our study indicate that supplemental BET may play a role in regulating the immunity of growing Murrah buffalo calves.

PSIV-24 Evaluation of different colostrum feeding volumes on serum immunoglobulin G concentration and metabolic profiles of calves in high altitude area

Abstract Qinghai-Tibet Plateau is the highest plateau in the world, reputed as “the roof of the world” and “the world’s third pole”. Its ecological environment is characterized by low atmospheric oxygen pressure, cold, and limited feed supplies. This study aimed to investigate the serum immunoglobulin G (IgG) concentration and metabolic profiles of calves in high altitude area (3,650 m) fed different volumes of colostrum [8, 12, or 15% of birth body weight (BW)] using untargeted metabolomics strategies. Neonatal Holstein hybrid heifer calves (n = 44) were randomly divided into 1 of the 3 colostrum feeding amounts: 8% of birth BW (Low volume, L), 12% of birth BW (Middle volume, M), and 15% of birth BW (High volume, H) in colostrum. To safeguard the efficiency of colostrum intake, the colostrum was fed to calves within 0.5 h and 6 h after birth. The serum samples at 24 h after birth were collected for IgG concentration determination by indirect enzyme-linked immunosorbent assay (ELISA) and for LC-MS/MS metabonomic analysis. As the volumes of colostrum increased, there was a linearly increased in the serum IgG concentration (P &amp;lt; 0.01). Differential metabolites were selected according to the following 3 conditions: minimum fold change (FC) &amp;gt; 2, P-value &amp;lt; 0.01 in single-dimensional statistical analysis, and variable importance in projection (VIP) &amp;gt; 1 in the OPLS-DA model. Multivariate statistical analyses were performed to visualize differences among groups. Based on the screening criteria, a total of 3 differential metabolites (22 alpha-Hydroxy-campesterol, N-Myristoyl Histidine, and Calcitetrol) were detected between L and M, of which all differential metabolites were down-regulated. Six differential metabolites were detected between M and H, of which PC[P-18:1(11Z)/18:1(12Z)-2OH(9,10)] was up-regulated and 5 differential metabolites including 1-arachidonoyl-2-hydroxy-sn-glycero-3-phosphate, propanoyl phosphate, ascorbic acid 6-palmitate, 20-hydroxyecdysone, and 6’’’-deamino-6’’’-hydroxyparomomycin II were down-regulated. There were 28 differed metabolites (including leucyl-tryptophan, calcitetrol, 3’’-Oxoribostamycin) between L and H, of which 9 differential metabolites were up-regulated and 19 differential metabolites were down-regulated (Figure 1). Based on KEGG metabolic enrichment pathway analysis and pathway topology analysis, porphyrin metabolism was identified as the most impacted pathway between L and H (Figure 2). In conclusion, increasing colostrum volumes significantly increased serum IgG concentrations at 24 h after birth, favoring the success of the transfer of passive immunity. Alterations in serum metabolome of calves in the Qinghai-Tibet Plateau fed different volumes of colostrum were successfully revealed by untargeted metabolomics. The role of the identified differential metabolites and enriched pathway in the transfer of passive immunity in calves at high altitude deserves further investigation. Keywords: calf, colostrum volumes, high altitude area

PSVIII-9 Effects of growth implants and timing of vaccination on calf immunity and growth performance

Abstract This study assessed calf growth performance and blood parameters of beef calves under different growth implants and timing of vaccination protocols. Crossbreed beef calves (n = 59) were stratified by birth body weight (BW) and age (41 ± 5.2 kg of BW and 70 ± 8 d of age) and randomly assigned in a split-plot design with implant strategy as the main plot and timing of vaccination as the subplot. The main plot (treatment) consisted of 3 implant strategies: 1) Synovex C (SC; n = 20; 100 mg progesterone/10 mg estradiol benzoate, or 2) Synovex One Grower (SG; n = 19; 150 mg trenbolone acetate and 21 mg estradiol benzoate; or 3) no implant (CON; n = 20). Subplot treatments were the timing of vaccination booster against bovine respiratory disease pathogens on 1) weaning (WV; n = 29) or 2) 7-d post-weaning (PWV; n = 30). Cow-calf pairs were treated alike in a single pasture during the pre-weaning phase, receiving the same vaccine (Bovi-Shield Gold One Shot and Ultrabac 7) on d 0 (implantation day) and booster time (WV or PWV). After weaning (approximately 187 d of age), calves were allocated in a single pen receiving ad libitum hay until d 60 post-weaning. Body weight and blood were collected on d 0, weaning, d 0 and 28 relative to vaccination booster, and d 60 post-weaning. Blood was collected to determine insulin-like growth factor (IGF-1), cortisol, and leptin concentrations and to perform a complete blood cell count. WV calves had decreased cortisol concentrations on booster day and 28 d post-vaccine (P = 0.01). Regardless of implant treatment, calves tended to have decreased IGF-1 concentrations 28-d post-vaccine booster (P = 0.09). An effect of treatment (P &amp;lt; 0.01) was detected for lymphocyte counts, with CON having greater concentrations vs. SG and SC calves. A treatment × timing of vaccination (P &amp;lt; 0.01) interaction was detected for monocyte counts, where SG-PWV calves had the greatest concentrations. A treatment effect (P &amp;lt; 0.02) was observed for eosinophil percentage, where SG had reduced percentages than CON, while SC was intermediate. An effect of treatment was detected for leptin (P &amp;lt; 0.01), with SG calves having the least, CON being intermediate, and SC the greatest concentrations. From d 0 to 60 d post-weaning, SG tended to have greater ADG (P ≤ 0.07) compared with CON, while SC was intermediate. On d 28 and d 35 post-weaning, calves implanted with SG were heavier (P ≤ 0.04) than the CON but not than SC. In summary, this study demonstrates that growth implants and timing of vaccination significantly affect both physiological parameters and growth performance in beef calves. Implanting calves with Synovex One Grower resulted in improved growth performance.

111 Factors affecting transfer of passive immunity in beef calves

Abstract Data from 9 calving experiments were used to investigate relationships of dam, calf, and colostrum factors with passive transfer in beef calves. Serum was collected at 48.33 ± 1.25 (SD) h of age for 313 calves, and single rear quarter colostrum yields were determined pre-suckling for dams of 117 calves. Serum and colostrum IgG concentrations were determined by ELISA. Relationship of serum IgG with colostrum variables was determined using Pearson correlation coefficients. Serum IgG was positively correlated (P ≤ 0.002) with colostrum IgG (r = 0.47) and protein (r = 0.45) concentrations and colostrum total IgG (r = 0.28) but tended to be negatively correlated (r = -0.17, P = 0.06) with colostrum yield. Based on passive transfer thresholds in the literature, 3 calves (0.96%) had &amp;lt; 8 mg/mL serum IgG, 16 calves (5.1%) &amp;lt; 16 mg/mL, and 43 calves (13.7%) had &amp;lt; 24 mg/mL. For this analysis, calves with serum IgG &amp;lt; 24 mg/mL at 48 h were considered to have failure of passive transfer (FPT). Continuous variables (dam BW and calf size, 48-h serum chemistry panel, and time to stand) were compared for FPT versus non-FPT calves using a mixed model with FPT class (fixed effect) and experiment (random effect). Calves with FPT had less (P ≤ 0.03) circulating triglycerides, glucose, calcium, magnesium, total protein, globulin, and gamma-glutamyl transferase but greater (P ≤ 0.001) circulating non-esterified fatty acids, sodium, chloride, and total bilirubin than non-FPT. Effects of categorical variables on calf 48-h serum IgG were determined using separate mixed models with variable (fixed) and experiment (random). Primiparous dams gave birth to calves that had less (P = 0.05) serum IgG at 48 h than multiparous dams. Calves born to moderate dams (BCS = 5) had less (P = 0.007) serum IgG than those born to fleshy dams (BCS ≥ 6) and tended to have less (P = 0.08) serum IgG than calves born to thin dams (BCS &amp;lt; 5). Calf sex, calving season, calving difficulty score, and vigor score at 10 min did not affect (P ≥ 0.19) serum IgG. Relationships of calf 48-h serum IgG with continuous variables was also determined using Pearson correlation coefficients, and only r ≥ 0.20 or ≤ -0.20 are reported. Serum IgG was positively correlated (P ≤ 0.005) with 48-h serum total protein (r = 0.75), globulin (r = 0.76), gamma-glutamyl transferase (r = 0.32), and potassium (r = 0.20). Serum IgG was negatively correlated (P &amp;lt; 0.001) with gestation length (r = -0.22) and 48-h serum albumin (r = -0.43), sodium (r = -0.24), and total bilirubin (r = -0.27). Overall, beef calves in this dataset generally had successful passive transfer that was associated with several dam, calf, and colostrum factors.

Use of domestic biological drugs in reproduction of cattle

purpose of the work was to analyze the use of domestic biodrugs in the reproduction of cattle. In the scientifi c and economic experiment, three groups of dry cows (control, 1st and 2nd experimental) were formed according to the principle of analog groups, taking into account the clinical and physiological condition, age and live weight. In the 2nd series of the experiment, 3 groups of newborn heifers were formed in accordance with the groups of dams. The work scientifi cally substantiates and experimentally proves the eff ectiveness of using complex immunomodulatory biodrugs consisting of two main active components (yeast cells and vitamins) Salus-PE and Bovistim-K, in the technology of cow reproduction and calf rearing. It has been established that the use of biodrugs in late pregnant cows improved the course of the calving and postpartum periods, increased milk productivity and colostrum quality, forms stable colostral immunity in newborn calves, reduced the risks of respiratory and gastrointestinal diseases in young animals, contributing to better live weight gains. The tested complex immunomodulatory biodrugs activate hematopoiesis, compensatory mechanisms of the body, the population of immune cells in the blood, increased protein metabolism, the expression profi le of cellular and humoral factors of non-specifi c resistance. The use of the developed biodrugs during decornuation stimulated tissue regeneration, accelerated the process of scab formation, normalized the level of γ-globulins, activated the synthesis of α- and β-globulins, oxidation-reduction processes and metabolism, which ensured an increase in the immune status of the body of calves in the neonatal period. The economic effi ciency of using the biodrugs Salus-PE and Bovistim-K in the technology of cow reproduction in the 1st and 2nd experimental groups based on 1 ruble of additional costs was 2.63 and 4.50 rubles, and in the technology of raising calves 6.85 and 11.20 rubles, respectively.

Effect of suckler cow breed type and parity on the development of the cow-calf bond post-partum and calf passive immunity

BackgroundDevelopment of the cow-calf bond post-partum and passive immunity of calves from spring-calving beef × beef (B×B) and beef × dairy (B×D) cow genotypes was determined using primiparous and multiparous (Experiment 1), and primiparous and second-parity (Experiment 2) animals. In Experiment 1, calves either suckled colostrum naturally (‘natural-suckling’) (n = 126), or were fed colostrum, using an oesophageal-tube (‘artificially-fed’) (n = 26), from their dam within 1-h post-partum. In Experiment 2, all calves (n = 60) were artificially-fed colostrum from their dam. Prior to colostrum suckling/feeding, colostrum was sampled for IgG analysis. The cow-calf bond was assessed using CCTV recordings during the first 4-h post-partum. Calves were blood sampled at 48-h post-partum to determine IgG and total protein (TP) concentrations, and zinc sulphate turbidity (ZST) units.ResultsThere was no difference (P > 0.05) in cow licking behaviours and calf standing and suckling behaviours between the genotypes, except in Experiment 2 where B×D calves had more attempts to suckle before suckling occurred (P ≤ 0.05) compared to B×B calves. In Experiment 1, multiparous cows licked their calves sooner (P ≤ 0.05) and for longer (P < 0.01), and their calves had fewer attempts to stand (P < 0.001), stood for longer (P = 0.05), and had fewer attempts to suckle before suckling occurred (P < 0.001) than primiparous cows; there was no parity effect on cow-calf behaviour in Experiment 2. Colostrum IgG concentrations and measures of calf passive immunity did not differ (P > 0.05) between the genotypes in either Experiment. In Experiment 1, colostrum IgG concentrations were greater (P ≤ 0.05) in multiparous compared to primiparous cows and their calves had superior (P ≤ 0.05) passive immunity; no effect of parity was found in Experiment 2. Passive immunity did not differ (P > 0.05) between suckled and artificially-fed calves in Experiment 1.ConclusionsCow genotype had little effect on cow-calf behaviours, but under ‘natural-suckling’ conditions primiparous cows expressed maternal inexperience and their calves were less vigorous than multiparous cows. Colostrum IgG concentration and calf passive immunity measures were unaffected by genotype, but under ‘natural-suckling’ conditions calves from primiparous cows had lower passive immunity.

Survey on colostrum management by German dairy farmers focusing on frozen colostrum storage

Because calves are born with low levels of antibodies, effective colostrum management is one of the most critical factors for successful calf rearing. A timely and adequate supply of sufficiently high-quality colostrum immediately after birth is essential to ensure the passive immunization of calves. Frozen colostrum reserves are recommended to fulfill the immunological and nutrient requirements of newborn calves, even in exceptional situations; however, the implementation rates on German dairy farms and challenges of realization remain unclear. A 33-question online survey, focused on frozen colostrum reserves, was developed to obtain an overview of colostrum management practices on German dairy farms. The questionnaire was divided into 3 sections: 1. personal data; 2. farm characteristics; 3. colostrum management. Of the 155 responses we received, 63.9% were from female farmers, and 35.5% were from male farmers. Conventional farming was practiced on 89.0% of farms, and organic farming was practiced on 7.1% of farms. Of the respondents, 89.0% froze colostrum. The main reasons for freezing colostrum were: 1. the dam does not produce enough colostrum; 2. the dam cannot be milked; or 3. in cases where the dam dies during birth. Farmers primarily froze colostrum from cows during their third to fifth lactation. Before freezing, 33.1% of the respondents measured indicators in the colostrum to estimate Ig concentrations, whereas 2.3% determined the colostrum quality after freezing. Reusable and disposable PET deposits (23.1%, 22.3%) and ColostroBags (20.0%) were the primary containers used to freeze colostrum. The main reasons for not freezing colostrum were the high labor intensity and the availability of fresh colostrum from other cows. Thawing methods included buckets (47.7%) and professional water baths (13.8%). The survey identified areas in which improved knowledge transfer could enhance colostrum management. Furthermore, there appeared to be a lack of specific, feasible instructions for employees concerning the practical implementation of colostrum management. Most importantly, the regular determination and documentation of Ig concentrations should be emphasized. The added value of stored colostrum, relative to a greater workload, should also be promoted, particularly on smaller farms.

The influence of adjuvants ISA 61 and ISA 50 on the antigenic activity, the ability to form colostral immunity and the effectiveness of experimental samples of the vaccine &lt;i&gt;KOMBOVAC-A&lt;/i&gt;

The article provides a comparative assessment of two experimental samples of the seven-component vaccine KOMBOVAС-A, manufactured with adjuvants ISA 61 and ISA 50, in terms of: antigenic activity (in laboratory and naturally susceptible animals); influence on the formation of colostral immunity in calves when vaccinating pregnant cows, as well as effectiveness in livestock farming conditions unfavorable for the main respiratory and intestinal diseases of calves of viral etiology. It was found that the vaccine sample based on the ISA 61 adjuvant had a higher antigenic activity compared to a similar sample based on the ISA 50 adjuvant, inducing a higher level of synthesis of post-vaccination antibodies. The use of the vaccine in conditions of a dysfunctional livestock farm has reduced the morbidity and mortality of calves, while the vaccine sample made on the basis of ISA 61 oil proved to be more effective.

Colostrum Replacement and Serum IgG Concentrations in Beef Calves Delivered by Elective Cesarean Section.

Assistance during calving and cesarean section (C-section) are important risk factors for the failure of transfer of passive immunity (FTPI) in beef calves, which increases the risk of morbidity and mortality in beef calves during the preweaning period. Colostrum replacement recommendations for beef calves, and especially for those delivered by C-section, are unavailable. The objective of this study was to determine whether or not colostrum replacement or supplementation with a commercially available product could increase serum IgG concentrations in beef calves delivered by elective C-section, compared to beef calves that nursed colostrum naturally. An elective C-section was performed in 32 pregnant beef cows and first-calf heifers. Immediately after delivery, newborn calves were randomly assigned to one of three different treatment groups. Group A calves (n = 7) were fed one packet of a commercial colostrum replacer (CR) product providing 60 g of IgG within 30 min of life. A second packet of the same CR was fed at 6 h of life. Group B calves (n = 13) were fed the same CR at the same frequency as group A; however, these calves were reunited with their dams after the second CR feeding to allow additional nursing of maternal colostrum. Group C calves (n = 12) were united with their dams immediately after surgery without colostrum intervention. Serum IgG levels at 48 h of life were greater in group C calves and in calves born to multiparous cows. Based on the results of this study, neither colostrum replacement nor supplementation result in higher serum IgG concentrations in beef calves delivered by elective C-section compared with natural nursing.

Evaluation of longitudinal passive immunity transfer against lumpy skin disease virus in calves by different serological methods

To implement effective lumpy skin disease (LSD) control measures, such as timely vaccination, particularly in calves and serological monitoring, it is necessary to evaluate immune response after vaccination, both in adult cattle and in their calves. The aim of this study was to evaluate passive immunity transfer and duration of maternal antibodies against lumpy skin disease virus (LSDV) in calves born to vaccinated cows by two different serological methods. The longitudinal study was carried out on two farms in Serbia where no cases were reported during LSD outbreak in 2016. Fifteen cows on each farm were vaccinated and revaccinated with attenuated vaccine - Neethling strain. A total of 30 cows and 30 calves on both farms were included in the study. Serum samples from cows were collected on calving day and serum samples from their respective calves on days 10, 20, 30, 45, 60, 75, 90, 105 and 120 after birth. Colostrum samples were collected only from 15 cows on one farm. In order to determine the presence of antibodies against LSDV a total of 30 cow sera samples, 15 colostrum samples and 270 calf sera samples were examined by commercial enzyme-linked immunosorbent assay (ELISA) and modified virus neutralization test (VNT). Overall, the performance of both serological tests was very satisfactory. The results of this longitudinal study showed that persistence of passive immunity in calves is less than 4 months, and that most calves are not protected against LSDV at that age. Since the vaccination is the most important control measure against LSDV, the recommended age of six months for vaccination of calves born to vaccinated cows should be reassessed to achieve the most optimal protection against LSD.

Persistence of passive immunity in calves receiving colostrum from cows vaccinated with a live attenuated lumpy skin disease vaccine and the performance of serological tests.

This study aimed to determine the persistent duration of maternal immunity against lumpy skin disease virus (LSDV) in dairy calves born from vaccinated cows using a virus neutralization test (VNT). The performance of the VNT and an in-house-ELISA test was also determined. Thirty-seven pregnant cows from 12 LSD-free dairy farms in Lamphun province, Thailand were immunized with a homologous Neethling strain-based attenuated vaccine and calved from December 2021 to April 2022. Blood samples from dam-calve pairs were collected within the first week after calving. Subsequently, blood samples were taken from the calves at monthly intervals over a period of 4 months and tested for the humoral immune response using a VNT. The calf sera were also tested with an in-house ELISA test to estimate the accuracy of both tests using a Bayesian approach. For the results, antibodies against LSDV can persist in cows for 4-9 months post-vaccination. Moreover, neutralizing antibodies and LSDV-specific antibodies against LSDV were detected in the majority of calves (75.68%) during the first week after colostrum intake. However, the percentage of seropositive calves declined to zero by day 120, with seropositivity dropping below 50% after day 60. Only a small number of seropositive calves (approximately 13.51%) were observed on day 90. These findings indicated that passive immunity against LSDV can last up to 3 months. The median of posterior estimates for sensitivity (Se) and specificity (Sp) of the VNT were 87.3% [95% posterior probability interval (PPI) = 81.1-92.2%] and 94.5% (95% PPI = 87.7-98.3%), respectively. The estimated Se and Sp for the ELISA test were 83.1% (95% PPI = 73.6-92.6%) and 94.7% (95% PPI = 88.4-98.5%), respectively. In conclusion, this study illustrates the transfer and persistence of maternal passive immunity against LSDV to calves under field conditions. This highlights a potential three-month vaccination gap in calves born from vaccinated cows, while an in-house ELISA test can be used as an ancillary test for LSDV immune response detection. However, further research is required to assess the vaccination protocols for calves as young as 2 months old to precisely determine the duration of maternal immunity.

Zinc about it - zinc and calf immunity.

Micronutrients, such as vitamins and trace minerals, are critical for supporting growth, performance, health and maintaining redox balance. Zinc (Zn), an essential micronutrient, aids the functioning of innate and adaptive immune cells. This scoping review aims to assemble and evaluate the evidence available for the role of Zn within calf immunity. Relevant literature was identified within Web of Science, PubMed, and CABI using search terms specific to the major innate and adaptive immune cell populations. There was no evidence that Zn supplementation altered neutrophil, natural killer cell, or T-cell functions. However, there was limited evidence to support Zn supplementation with reduced monocyte numbers, but there was no evidence to associate the monocytopenia with improvements in monocyte function. There is moderate evidence to suggest that Zn supplementation was beneficial for maintaining epithelial barriers of integumental and mucosal surfaces. The evidence supports supplementation above the current industry recommendations for improving immunoglobulin (Ig) production, with the strongest results being observed for IgG and IgM. Moreover, Zn supplementation was associated with reduced proinflammatory cytokine production, which may reduce inflammation-associated hypophagia and warrants further investigation. Furthermore, Zn reduced the duration of clinical signs in animals facing respiratory disease and diarrhea. However, consensus is needed about the optimal dose, route, and Zn formulation most appropriate for supporting immunity. In conclusion, while the literature supports that Zn could enhance calf immunity, there is insufficient evidence to adequately determine the extent to which Zn impacts innate immune cell and T-cell functions. Determination of the immune cell functions susceptible to modification by Zn supplementation is an important knowledge gap for enhancing the understanding of Zn and calf immunity.

The effects of a non-steroidal anti-inflammatory drug on behavior and physiological parameters of beef cows and calves assisted at calving

An assisted calving can negatively impact the health and behav­ior of beef cows and calves. Non-steroidal anti-inflammatory drugs (NSAIDs) administered after a difficult calving to the cow or the calf as a pain mitigation strategy have been shown to im­prove behaviors in dairy cows and calves, weight gain in beef and dairy calves, and vigor in dairy calves. However, the effects of NSAIDs on beef cows’ and calves’ behaviors related with pain and cow-calf bonding after an assisted calving have not been studied. Therefore, the objective of this study was to investigate the effects of administering an NSAID to beef cattle after an as­sisted calving by measuring changes in behaviors related with pain and the cow-calf bond, transfer of passive immunity in calves, and physiological parameters related with pain.

Comparison of Salmonella Dublin SRP vaccination programs on the development of immunity in calves

Salmonella Dublin is a common cause of calf illness and is en­demic in many regions of the U.S. dairy industry. A 2016 report from the National Veterinary Services Lab found S. Dublin was the most commonly isolated Salmonella serotype obtained from ill cattle in the U.S. This serotype is also considered to be host-adapted in bovine and therefore carrier animals that appear normal can be shedders and a source for maintaining the infec­tion within a herd. As such, finding mechanisms to protect naïve animals from clinical disease can reduce losses in dairy herds. The objective of this work was to describe the immune response stimulated by experimental Salmonella Dublin SRP vaccines.

Bayesian estimation of sensitivity and specificity of IgG and serum total protein cutoff values for the diagnosis of failed transfer of passive immunity in neonatal beef calves

Calves with failed transfer of passive immunity (FTPI) possess increased risk of preweaning disease. Common tests for FTPI such as radial immunodiffusion (RID) and optical refractom­etry (OR) have inherent imprecision. The objective of this study was to estimate test sensitivity and specificity for various IgG concentrations and serum total protein values (STP) to classify neonatal beef calves with FTPI.

Serological Profile for Major Respiratory Viruses in Unvaccinated Cows from High-Yielding Dairy Herds.

This study aims to determine the serological profile of high-yielding dairy cows for four main viruses (bovine alphaherpesvirus 1 (BoAHV1), bovine viral diarrhea virus (BVDV), bovine parainfluenza virus 3 (BPIV3), and bovine respiratory syncytial virus (BRSV)) related to bovine respiratory disease (BRD) in cattle herds worldwide. In this survey, 497 blood serum samples were collected from non-vaccinated dairy cows without clinical respiratory signs in 39 herds in the central-eastern mesoregion of Paraná State, South Brazil. The presence of neutralizing antibodies was determined by virus neutralization (VN) tests. VN antibodies against BoAHV1, BVDV, BPIV3, and BRSV were detected in 355 (71.4%), 280 (56.3%), 481 (96.8%), and 315 (63.4%) serum samples, respectively. The frequencies of seropositive herds for BoAHV1, BVDV, BPIV3, and BRSV were 79.5 (n = 31), 82.0 (n = 32), 100 (n = 39), and 84.6% (n = 33), respectively. The frequencies of seropositive cows varied according to the type of herd management and the number of cows in the herd. The detection of VN antibodies in unvaccinated dairy cattle herds demonstrated the endemic circulation of the four viruses in the herds evaluated. For BRD prevention, it is recommended to implement a vaccination program for cows that provides passive immunity in calves and active immunity in cows.

Intake of compound probiotics accelerates the construction of immune function and gut microbiome in Holstein calves.

The unstable gut microbiome and incomplete intestinal function of newborn calves are important factors for the high incidence of early diarrhea. This study presents an effective strategy to improve the overall immunity and gut microbiome in calves and provides new insights into the application of compound probiotics in mammals.