Lawrence K, Broerse N, Hine L, Yapura J, Tulley W J
a Institute of Veterinary, Animal and Biomedical Sciences , Massey University , Palmerston North , New Zealand.
b Current address: North Canterbury Veterinary Clinics , 26 Mouse Point Rd, Culverden , New Zealand.
N Z Vet J. 2017 Jan;65(1):1-5. doi: 10.1080/00480169.2016.1224207. Epub 2016 Aug 30.
To determine the prevalence of failure of passive transfer (FPT) of maternal antibodies, to identify management factors associated with FPT, and to determine the relationship between interval from the start of calving and calf management practices on concentrations of total protein in the serum of calves, from a sample of spring-calving dairy herds in the Manawatu region of New Zealand.
This was an observational study involving 11 dairy farms in the Manawatu region serviced by Massey University Farm Services Clinic. Blood samples were collected from calves <1-week-old during August and September 2012 and concentration of total protein in serum was assessed by refractometry. FPT was defined as concentrations of total protein in serum ≤50 g/L. A questionnaire on early calf rearing practices was completed on each farm. Linear mixed and generalised linear mixed models were used to determine associations with concentrations of total protein in serum and risk of FPT.
The mean concentration of total protein in serum for the 230 samples collected was 60.6 (SE 0.93) g/L and 57/230 (24.8 (95% CI=19.3‒30.9)%) calves were diagnosed with FPT. Two variables, days from planned start of calving to when the calf was sampled, and reportedly feeding colostrum for the first 4 days post-partum, were associated with increased concentrations of total protein in serum (p<0.05). There was also an association between the odds of FPT for calves sampled in a particular week and the proportion of the total herd calving in that same week (p<0.005).
Feeding colostrum for 4 days from birth and increasing days from planned start of calving to calf sampling were associated with increased concentrations of total protein in serum. FPT on the surveyed farms appeared to be associated with an inability to adequately manage the total number of new born calves during the busiest period of calving.
在新西兰马纳瓦图地区春季产犊的奶牛场样本中，确定母源抗体被动转运失败（FPT）的发生率，识别与FPT相关的管理因素，并确定从产犊开始的时间间隔和犊牛管理措施与犊牛血清总蛋白浓度之间的关系。
这是一项观察性研究，涉及由梅西大学农场服务诊所服务的马纳瓦图地区的11个奶牛场。在2012年8月和9月期间，从1周龄以下的犊牛采集血样，并通过折射法评估血清总蛋白浓度。FPT定义为血清总蛋白浓度≤50g/L。在每个农场完成了一份关于早期犊牛饲养措施的问卷。使用线性混合模型和广义线性混合模型来确定与血清总蛋白浓度和FPT风险的关联。
采集的230个样本的血清总蛋白平均浓度为60.6（标准误0.93）g/L，57/230（24.8（95%CI=19.3‒30.9）%）头犊牛被诊断为FPT。两个变量，从计划产犊开始到犊牛采样的天数，以及据报道在产后头4天饲喂初乳，与血清总蛋白浓度升高相关（p<0.05）。在特定一周采样的犊牛发生FPT的几率与同一周内全群产犊的比例之间也存在关联（p<0.005）。
从出生开始饲喂4天初乳以及从计划产犊开始到犊牛采样的天数增加与血清总蛋白浓度升高相关。在被调查的农场中，FPT似乎与在最繁忙的产犊期无法充分管理新生犊牛总数有关。
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