Skirving Rebel, Bottema Cynthia D K, Laven Richard, Hue Do T, Petrovski Kiro R
Davies Livestock Research Centre, School of Animal & Veterinary Sciences, University of Adelaide, Roseworthy, SA 5371, Australia.
Gambier Vets Pty. Ltd., Mount Gambier, SA 5290, Australia.
Animals (Basel). 2022 Oct 24;12(21):2912. doi: 10.3390/ani12212912.
The objective of this observational study was to estimate the incidence of inadequate transfer of passive immunity (ITPI) on five pasture-based dairy farms in South Australia. Heifer calf uptake of colostrum was evaluated within the first 1−7 days of age (n = 2638) using a digital refractometer to estimate each calf’s serum total protein concentration, as an indicator of colostrum uptake. Results of <51 g/L indicated inadequate transfer of passive immunity (ITPI). The data showed that the incidence of ITPI on the farms was 6.5%, 31.3%, 48.8%, 49.7% and 52.4%. The incidence of ITPI was calculated in relation to the age of the calf at testing and the breed of calf, and no significant differences were found. A significant difference was found in the incidence of ITPI when comparing the calf’s first feed after separation from the dam (colostrum versus a colostrum-transition milk mixture). The farm with the lowest incidence of ITPI collected calves twice a day, measured colostrum quality on farm with a Brix refractometer and ensured that each calf received an appropriate amount of high-quality colostrum soon after collection. Further studies are required to establish the risk factors of ITPI in South Australian dairy heifers.
这项观察性研究的目的是估计南澳大利亚五个以牧场为基础的奶牛场被动免疫转移不足（ITPI）的发生率。在出生后1 - 7天内对小母牛犊牛的初乳摄入情况进行评估（n = 2638），使用数字折射仪估计每头犊牛的血清总蛋白浓度，作为初乳摄入的指标。结果<51 g/L表明被动免疫转移不足（ITPI）。数据显示，各农场ITPI的发生率分别为6.5%、31.3%、48.8%、49.7%和52.4%。根据检测时犊牛的年龄和犊牛品种计算ITPI的发生率，未发现显著差异。在比较犊牛与母牛分离后的首次喂食（初乳与初乳 - 过渡乳混合物）时，发现ITPI的发生率存在显著差异。ITPI发生率最低的农场每天两次收集犊牛，在农场使用糖度折射仪测量初乳质量，并确保每头犊牛在收集后不久能获得适量的优质初乳。需要进一步研究以确定南澳大利亚奶牛小母牛ITPI的风险因素。
