Cummins C, Berry D P, Murphy J P, Lorenz I, Kennedy E
School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland; Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland.
Teagasc, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland.
J Dairy Sci. 2017 Jan;100(1):525-535. doi: 10.3168/jds.2016-10892. Epub 2016 Nov 9.
The objective of the present study was to compare serum IgG concentration, weight gain, and health characteristics in Irish spring-born dairy calves fed colostrum stored using a range of conditions. Immediately after birth, 75 dairy heifer calves were assigned to 1 of 5 experimental colostrum treatments: (1) fresh pasteurized colostrum, fed immediately after pasteurization; (2) fresh colostrum, fed immediately after collection but not pasteurized; (3) colostrum stored unpasteurized at 4°C in a temperature-controlled unit for 2d before being fed to calves; (4) colostrum stored unpasteurized at 13°C in a temperature-controlled unit for 2d before being fed to calves; and (5) colostrum stored unpasteurized at 22°C in a temperature-controlled unit for 2d before being fed to calves. All colostrum had IgG concentrations >50g/L and was fed to calves promptly after birth. Blood samples were obtained from calves via the jugular vein at 0h (before colostrum feeding) and at 24h of age to determine the rate of passive transfer of IgG; individual calf live-weights were recorded to monitor weight gain (kg/d) from birth to weaning. Colostrum stored in warmer conditions (i.e., 22°C) had >42 times more bacteria present and a pH that was 0.85 units lower and resulted in a serum IgG concentration that was almost 2 times lower compared with colostrum that was pasteurized, untreated, or stored at 4°C for 2d. Colostrum stored at 4°C for 2d had more bacteria present than pasteurized and fresh colostrum but did not result in reduced calf serum IgG concentrations. Average daily weight gain from birth to weaning did not differ among treatments. Even if colostrum has sufficient IgG (>50g/L) but cannot be fed to calves when freshly collected, storage at ≤4°C for 2d is advisable to ensure adequate passive transfer when it is consumed by the calf.
本研究的目的是比较在一系列条件下储存初乳喂养的爱尔兰春季出生的奶牛犊的血清IgG浓度、体重增加和健康特征。出生后立即将75头奶牛犊分配到5种实验性初乳处理中的一种：(1)新鲜巴氏杀菌初乳，巴氏杀菌后立即喂养；(2)新鲜初乳，采集后立即喂养但未巴氏杀菌；(3)未巴氏杀菌的初乳在温度控制单元中于4°C储存2天，然后喂给犊牛；(4)未巴氏杀菌的初乳在温度控制单元中于13°C储存2天，然后喂给犊牛；(5)未巴氏杀菌的初乳在温度控制单元中于22°C储存2天，然后喂给犊牛。所有初乳的IgG浓度均>50g/L，并在犊牛出生后立即喂给它们。在0小时（初乳喂养前）和24小时龄时通过颈静脉从犊牛采集血样，以确定IgG的被动转移率；记录每头犊牛的个体体重，以监测从出生到断奶的体重增加（kg/天）。储存在较温暖条件（即22°C）下的初乳中存在的细菌多出42倍以上，pH值低0.85个单位，导致血清IgG浓度与经过巴氏杀菌、未处理或在4°C储存2天的初乳相比低近2倍。在4°C储存2天的初乳中存在的细菌比巴氏杀菌和新鲜初乳更多，但并未导致犊牛血清IgG浓度降低。各处理之间从出生到断奶的平均日增重没有差异。即使初乳具有足够的IgG（>50g/L），但如果刚采集时不能喂给犊牛，建议在≤4°C下储存2天，以确保犊牛食用时能有足够的被动转移。
