Bandlow Katherine S, King Ailbhe, Kennicutt Kelsie C, Brody Shoshana, Chigerwe Munashe
Department of Veterinary Medicine and Epidemiology, University of California, Davis, Davis, CA, United States.
Center for Integrative Mammalian Research, Department of Clinical Sciences, Ross University School of Veterinary Medicine, Basseterre, Saint Kitts and Nevis.
Front Vet Sci. 2023 Feb 24;10:1094272. doi: 10.3389/fvets.2023.1094272. eCollection 2023.
Acquisition of adequate transfer of passive immunity (ATPI) by calves depends on the absorption of sufficient mass of colostral immunoglobulin G (IgG). Several studies report conflicting evidence regarding the ability of feeding pooled colostrum to achieve ATPI. Pooling colostrum is practical and efficient for some dairies, and recommendations are required to prevent failure of transfer of passive immunity (FTPI) in calves following pooling. This study aimed to determine the effect of pooling colostrum on serum IgG concentrations, FTPI, and preweaning mortality in calves. A prospective study was performed on two conventional Jersey dairy farms where heat treatment of colostrum occurred in the same colostrum processing kitchen. Four to 10 cows contributed to colostrum pools. A sample of the colostrum pool fed to the calves and serum from calves at 24-72 h was collected for IgG concentration determination by single radial immunodiffusion assay. Multivariable and logistic regression analyses were performed to evaluate factors that predicated serum IgG concentrations and the probability of FTPI, respectively. A Cox proportional hazard model analysis was performed to determine risk factors for mortality over the preweaning period. A total of 164 calves fed 28 colostrum pools were enrolled. Birth weight, number of colostrum feedings and pool IgG concentrations were significant predictors of calf serum IgG concentrations at 24-72 h, whereas the number of colostrum feedings and age at bleeding to determine passive transfer status were not significant predictors of calf serum IgG concentrations at 24-72 h. The prevalence of FTPI was 4.9%. Birth weight, pool IgG concentrations, number of colostrum feedings, and age at bleeding to check for passive transfer status were not significant predictors of the probability of FTPI at 24-72 h. The incidence of mortality was 4.3%. Passive transfer status was not a predictor of mortality. Our study demonstrates the effect of pooling colostrum on serum IgG concentrations even in herds where colostrum with higher median colostrum IgG concentrations is fed to calves. The results emphasize the recommendations to assess pooled colostrum IgG concentrations before feeding calves.
犊牛获得足够的被动免疫转移（ATPI）取决于初乳中免疫球蛋白G（IgG）的充分吸收。多项研究报告了关于饲喂混合初乳实现ATPI能力的相互矛盾的证据。对于一些奶牛场来说，混合初乳既实用又高效，因此需要相关建议来预防犊牛在混合初乳后出现被动免疫转移失败（FTPI）的情况。本研究旨在确定混合初乳对犊牛血清IgG浓度、FTPI和断奶前死亡率的影响。在两个传统的泽西奶牛场进行了一项前瞻性研究，初乳在同一个初乳加工厨房进行热处理。4至10头奶牛的初乳被混合在一起。收集饲喂给犊牛的混合初乳样本以及犊牛在24至72小时时的血清，通过单向辐射免疫扩散试验测定IgG浓度。分别进行多变量和逻辑回归分析，以评估预测血清IgG浓度和FTPI概率的因素。进行Cox比例风险模型分析，以确定断奶前期死亡率的风险因素。共有164头饲喂28个混合初乳的犊牛被纳入研究。出生体重、初乳饲喂次数和混合初乳IgG浓度是犊牛在24至72小时时血清IgG浓度的显著预测因素，而初乳饲喂次数和用于确定被动转移状态的采血时的年龄不是犊牛在24至72小时时血清IgG浓度的显著预测因素。FTPI的发生率为4.9%。出生体重、混合初乳IgG浓度、初乳饲喂次数和用于检查被动转移状态的采血时的年龄不是犊牛在24至72小时时FTPI概率的显著预测因素。死亡率为4.3%。被动转移状态不是死亡率的预测因素。我们的研究表明，即使在将初乳IgG浓度中位数较高的初乳饲喂给犊牛的牛群中，混合初乳对血清IgG浓度也有影响。结果强调了在饲喂犊牛之前评估混合初乳IgG浓度的建议。
