Prevalence and risk factors associated with failure of transfer of passive immunity in spring born beef suckler calves in Great Britain

Climatic and calf-related risk factors associated with failure of transfer of passive immunity in Holstein calves in a hot environment

This retrospective observational study aimed to assess the effect of temperature-humidity index (THI) at calving and in the last trimester of pregnancy and calve-related factors affecting passive transfer of maternal immunoglobulin using Brix refractometry in Holstein calves. Blood samples from 4411 Holstein calves from a single large dairy farm in spring 2022 were used. A subset of data containing 6318 calvings was used to determine the effect of climatic conditions on the occurrence of agammaglobulinemia. Risk factors predictive of failure of passive transfer (FPT) were calculated using multiple logistic models. Females were 1.4 times more likely not to have FPT (56%; Brix% > 8 equivalent to ≥ 10 g/L IgG) than males (47.2%). Calves born as singles increased the likelihood of not presenting FPT (52.6%) than calves born as twins (42.9%). Calves from cows with no dystocic delivery had a lower risk for FPT (odds ratio = 2.3) than calves from cows with dystocia. Agammaglobulinemia was 1.5 and 1.8 times more likely to occur in calves with THI ≥ 80 and ≥ 82 in the last trimester of gestation and at calving, respectively, than in calves not experiencing heat stress. Agammaglobulinemia was twice as likely to occur in male than in female calves. Calves with birth weight ≥ 37 kg and gestation length ≥ 275 kg were less likely to present agammaglobulinemia than lighter calves and calves with shorter gestation periods. This study raises questions for management practices in Holstein calves undergoing in utero heat stress and around calving to avoid agammaglobulinemia.

Total and pathogen-specific serum Immunoglobulin G concentrations in neonatal beef calves, Part 1: Risk factors

Maternal antibodies, delivered to the calf via colostrum, are crucial to prevent calfhood diseases and death. However, knowledge regarding the factors influencing this transfer of total and specific Immunoglobulin G (IgG) against common enteric and respiratory disease pathogens under current production conditions is sparse. The objectives of this study were to determine risk factors influencing total and pathogen-specific immunoglobulin G (IgG) concentrations against Escherichia coli (E. coli), bovine Rotavirus (BRoV), Cryptosporidium parvum (C. parvum), Bovine Viral Diarrhea Virus type 1 and 2 (BVDV), Parainfluenza Virus Type 3 (PI-3), Bovine Respiratory Syncytial Virus (BRSV), and Bovine Herpesvirus type 1 (BHV-1) in the serum of newborn beef calves. A total of 420 serum samples were collected from 1- to 7-day-old beef calves born on 6 farms in Alberta, Canada. Samples were analyzed by radial immunodiffusion for total IgG concentration and by enzyme-linked immunosorbent assays for pathogen-specific IgG concentrations against E. coli, BRoV, C. parvum, BVDV, PI-3, BRSV, and BHV-1. Multivariable multilevel linear and logistic regression models were built to evaluate dam- and calf-level risk factors associated with total and pathogen-specific IgG concentrations, failed transfer of passive immunity (FTPI; serum IgG < 10 g/L), and inadequate transfer of passive immunity (ITPI; serum IgG < 24 g/L). Farm was included as a random effect in all models to account for clustering at the herd level. Of the 420 calves included in this study, 5% (n = 20) and 18% (n = 75) of calves had FTPI and ITPI, respectively. Receiving colostrum intervention (i.e., being fed colostrum or colostrum product by either bottle or tube) was the most consistent risk factor for low total IgG concentration and significantly increased the odds of FTPI (Odds ratio (OR): 6.1, 95% CI: 2.0-18.9) and ITPI (OR: 4.8, 95% CI: 2.1-10.8). Calves born to cows consistently had higher pathogen-specific IgG concentrations (P < 0.0001), compared to calves born from heifers, and calves born to vaccinated dams had significantly higher BRoV, BVDV, and BHV-1-specific IgG concentrations. Interestingly, E.coli-specific IgG concentrations were associated with dam vaccination only in cows but not in heifers, which was likely due to differing vaccination strategies used. This study highlights the need to review and refine protocols with respect to dam vaccination and colostrum intervention on cow-calf operations.

Total and pathogen-specific serum Immunoglobulin G concentrations in neonatal beef calves, Part 2: Associations with health and growth

The association of poor transfer of passive immunity (TPI) with negative health outcomes is extensively researched in dairy calves. However, few field studies have examined the effect of total and particularly pathogen-specific Immunoglobulin G (IgG) concentrations on pre-weaning health and growth of beef calves. Hence, the objective of this study was to determine the association of total and pathogen-specific IgG concentrations against selected pathogens associated with neonatal calf diarrhea (NCD) and bovine respiratory disease (BRD) and the odds of pre-weaning treatments, mortality, and the growth of newborn beef calves. A total of 420 serum samples from 1- to 7-day old beef calves born on 6 farms in Alberta, Canada, were available for this observational study. Serum samples were analyzed by radial immunodiffusion for total IgG concentration and by enzyme-linked immunosorbent assays for pathogen-specific IgG concentrations against Escherichia coli (E. coli), bovine Rotavirus (BRoV), Cryptosporidium parvum (C. parvum), Bovine Viral Diarrhea Virus (BVDV), Parainfluenza Virus Type 3 (PI-3), Bovine Respiratory Syncytial Virus (BRSV), and Bovine Herpesvirus Type 1 (BHV-1). Data about the individual dam- and calf-level risk factors, calf treatments, mortality, and birth and weaning weights were collected. Multivariable multilevel logistic and linear regression models were built to evaluate the association of total and pathogen-specific IgG concentrations with the odds of mortality and average daily gain (ADG), respectively, while their association with the odds of pre-weaning treatment was established by univariable logistic regression analysis. The odds of calves with IgG concentrations < 10 g/L of getting treated (OR 7.9, 95 % CI 2.7-23.7) and dying (OR: 18.5, 95 % CI: 3.7-93.4) were higher than for their counterparts (P < 0.0001). Calves with IgG concentrations < 24 g/L also had higher odds of dying (OR: 10.1, 95 % CI: 2.6-40.2) and had lower ADG (-0.09 kg, SE: 0.03, P < 0.002) than calves with IgG concentrations ≥ 24 g/L. Higher BVDV-specific IgG concentration was protective against mortality (OR: 0.97, 95 % CI: 0.96-0.99, P < 0.001). This study highlights the negative association of inadequate TPI with health and growth of beef calves and thus, the need to refine protocols for dam vaccination and colostrum intervention in cow-calf operations to meet these higher IgG targets.

Vitality in Newborn Farm Animals: Adverse Factors, Physiological Responses, Pharmacological Therapies, and Physical Methods to Increase Neonate Vigor

Vitality is the vigor newborn animals exhibit during the first hours of life. It can be assessed by a numerical score, in which variables, such as heart rate, respiratory rate, mucous membranes' coloration, time the offspring took to stand up, and meconium staining, are monitored. Vitality can be affected by several factors, and therapies are used to increase it. This manuscript aims to review and analyze pharmacological and physical therapies used to increase vitality in newborn farm animals, as well as to understand the factors affecting this vitality, such as hypoxia, depletion of glycogen, birth weight, dystocia, neurodevelopment, hypothermia, and finally, the physiological mechanism to achieve thermostability. It has been concluded that assessing vitality immediately after birth is essential to determine the newborn's health and identify those that need medical intervention to minimize the deleterious effect of intrapartum asphyxia. Vitality assessment should be conducted by trained personnel and adequate equipment. Evaluating vitality could reduce long-term neonatal morbidity and mortality in domestic animals, even if it is sometimes difficult with the current organization of some farms. This review highlights the importance of increasing the number of stock people during the expected days of parturitions to reduce long-term neonatal morbidity and mortality, and thus, improve the farm's performance.

Effect of neonatal immunoglobulin status on the outcomes of spring-born suckler calves

BACKGROUND

Successfully rearing beef calves to weaning and beyond determines the economic performance of a beef farm. As such, it is important to understand the factors influencing performance outcomes.

METHODS

This study recorded the health events, mortality and growth rates of 674 calves born on 50 commercial beef farms in Great Britain using a postsampling questionnaire. All calves had a known postcolostral serum IgG status.

RESULTS

Preweaning mortality in the study population was 1.5% (10/674 calves), while the treatment rate was 6.4% (43/674 calves). Serum IgG, calf sex and dystocia were significant predictors of whether a calf died and/or required treatment. Average daily liveweight gain was calculated for calves where weaning weights were provided (n = 513). Serum IgG and calf sex were consistent predictors of calf growth rates, while birthweight and whether the calf was born to a cow or heifer were predictive in a model where average daily liveweight gain was converted to a binary response variable using the mean average daily liveweight gain on the calf's farm of origin.

LIMITATIONS

Morbidity and mortality were lower than comparable studies, potentially due to limitations in the study design.

CONCLUSION

Serum IgG and calf sex were significant explanatory variables that affected beef calf average daily liveweight gain. For every 5 g/L increase in serum IgG, the odds ratio of dying and/or requiring treatment decreased by 0.86.

Vaccination for the Prevention of Neonatal Calf Diarrhea in Cow-Calf Operations: A Scoping Review

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Since 1950, 113 articles on vaccines for the prevention of neonatal calf diarrhea have been published in the English literature

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Results for field trials using commercial vaccines for E. coli, bovine rotavirus, and bovine coronavirus infections are variable

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No field trials for commercial Salmonella vaccines have shown efficacy

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Vaccines for protozoal pathogens causing calf scours as well as the importance of several emerging enteric viruses of cattle need further research

Neonatal calf diarrhea (NCD), also known as scours, is an important disease of preweaned calves that affects the production and welfare of beef herds. While hygiene and nutrition are important in reducing the incidence of NCD, vaccination of dams or calves is often employed for the prevention of NCD. The present scoping review summarizes the available peer-reviewed scientific English literature on vaccination of dams or calves for the prevention of NCD over the past decades. The online databases Medline, CAB Abstracts, and Biosis were searched for articles on the topic published between 1950 and 2020. Online software was used to systematically evaluate 2807 citations for inclusion through pre-determined criteria in a 2-step process. In the 113 articles included in the review, vaccines tested targeted the pathogens E. coli (n = 43), bovine rotavirus (BRV, n = 38), Salmonella (n = 29), bovine coronavirus (BCV, n = 14), bovine viral diarrhea virus (n= 7), and other pathogens (n = 8). Field trials for commercial vaccines have been published for the most important pathogens, and results on efficacy are variable for such vaccines targeting BRV, BCV, and E. coli. Meta-analyses exploring efficacy of these vaccines would be helpful to practitioners and producers. No field studies on commercial products have shown efficacy for Salmonella vaccines so that a meta-analysis would unlikely come to a different conclusion. Further research is needed on vaccines for protozoal pathogens like Cryptosporidium parvum as well as on the importance of several emerging enteric viruses in calves.

Risk factor analysis for beef calves requiring assisted vaginal delivery in Great Britain

BACKGROUND

Dystocia has serious consequences for both mother and offspring. This study therefore aimed to identify risk factors for dystocia in vaginally delivered spring born beef calves in Great Britain (GB).

METHODS

Information on calving assistance, calf sex, birthweight, breed, twinning, dam parity and body condition score (BCS) was collected from 1131 calves across 84 GB farms. Variables were modelled against calving assistance as a binary response variable.

RESULTS

Twins (Odds Ratio [OR] = 5.45), Charolais calves (OR = 3.24), calves from primiparous dams (OR = 5.75) and male calves (OR = 1.75) were at significantly increased risk of requiring calving assistance across all models. Calves born to cows classed as thin (BCS < 2.5/5) were identified in the univariate analysis and in one of the multivariate models (OR = 1.92) as having an increased likelihood of dystocia.

CONCLUSIONS

Most beef herds have limited scope to manage cows on the basis of fetal gender and number. However, calf breed, dam body condition and management of primiparous dams can be manipulated to reduce the risk of dystocia and improve supervision. Poor body condition is a novel risk factor for dystocia in beef cows and worthy of further investigation.

Impact of volume, immunoglobulin G concentration, and feeding method of colostrum product on neonatal nursing behavior and transfer of passive immunity in beef calves

One-third of beef calves fail to achieve adequate transfer of passive immunity (TPI) through timely ingestion of colostrum, which substantially increases their risk of preweaning morbidity and mortality. Two randomized clinical trials were designed to assess the impact of volume, immunoglobulin G (IgG) concentration, and feeding method of colostrum product on neonatal nursing behavior and TPI. In Trial 1, 47 calves were randomly assigned to receive one of three colostrum interventions by oro-esophageal tube feeder (OET): 1 L with 100 g/L IgG, 1.4 L with 70 g/L IgG, or 2 L with 100 g/L IgG. In Trial 2, 29 calves were randomly assigned to be fed 1 L of colostrum product with 100 g/L IgG by either nipple bottle (NB) or OET. Colostrum intervention (i.e. feeding of colostrum product) occurred within 60 minutes of birth. Cow-calf pairs were monitored by video surveillance in individual stalls for 24 h. Dam colostrum was collected at 10 minutes and calf serum was collected at 24-36 h after birth to assess IgG concentration. Differences among colostrum intervention groups on latency to stand and nurse were analyzed using Kaplan-Meier survival curves and Cox proportional hazard models. The impact of colostrum intervention group on TPI was assessed using multivariable linear regression modeling. In Trial 1, calves fed 1.4 L with 70 g/L IgG by OET nursed from their dams statistically significantly earlier compared to calves fed 1 L with 100 g/L IgG (P = 0.003) and calves fed 2 L with 100 g/L IgG (P = 0.008). Six of the 15 calves in the NB group in Trial 2 refused to consume part of the colostrum feeding offered by bottle and required follow-up tube feeding of the remaining volume. These calves were analyzed as a separate group (NB + OET). Calves fed 1 L by NB stood and nursed statistically significantly earlier than calves fed by OET (P = 0.005) or a combination of NB + OET (P = 0.003). Calf serum IgG concentrations were not statistically significantly different among colostrum intervention groups (P > 0.1). Overall, the colostrum interventions assessed in this study led to only one calf with failed TPI. While statistically significant differences in serum IgG concentrations were not detected in this study, subsequent nursing behavior did vary and was improved by feeding a moderate volume (1.4 L with 70 g/L IgG) of colostrum when using an OET, and by using the NB when feeding a smaller volume (1 L with 100 g/L IgG).

A Scoping Review of On-Farm Colostrum Management Practices for Optimal Transfer of Immunity in Dairy Calves

Newborn calves are agammaglobulinemic and rely for their first immune protection almost completely on the transfer of immune constituents via colostrum. Inadequate colostrum management practices such as on-farm colostrum storage practices and colostrum feeding methods could affect immune components in colostrum and subsequently immune status of the newborn calf. We conducted a scoping review to identify all literature on the interactions between several colostrum management factors and immunological colostrum quality and passive transfer of immunity. Three major stages were defined: milking methods, colostrum treatment and storage, and administration procedures. Separate CAB Abstracts searches were performed for each of the subjects of interest. The search process was completed on November 9, 2020. Colostrum should be milked as soon as possible, as IgG concentration diminishes over time, probably due to dilution. To minimize bacterial contamination, it is advised to pasteurize colostrum in small batches at maximal 60°C for 30 or 60 min. Freeze/thawing of colostrum does not or only slightly affect IgG concentrations, as long as thawing is done au bain-marie and temperature does not exceed 40°C. In on-farm situations, it is difficult to determine the volume that should be fed as the variables contributing to the absorption of IgG by the newborn calf are many and include the quality of the colostrum, the bacterial contamination, the time interval between birth and first moment of feeding and the weight of the calf. Despite all knowledge regarding optimal colostrum management strategies, it remains challenging to predict the effects of certain colostrum management choices in field conditions. Therefore, we recommend measuring the colostral quality, weighing the newborn calf, adjusting the feeding volume accordingly to ensure optimal colostrum intake for each calf.