To determine factors affecting colostrum yield and quality, data from 148 cow-calf pairs over 6 experiments were combined. In each experiment, single rear quarter colostrum yield was obtained post-calving but pre-suckling. Colostrum IgG was determined by ELISA, and colostrum lactose, triglycerides (as a measure of total fat), and protein were determined by colorimetric analyses. Total IgG and nutrients were calculated as the concentration multiplied by single-quarter yield. Calf birth weight and expelled placental dry weight were also collected post-calving. Mixed linear models (experiment as a random effect) were used to determine the effects of dam age (primiparous: 2 yr, young: 3 to 4 yr, mature: ≥ 5 yr), dam peripartum body condition score (BCS; thin: < 5, moderate: 5 to 5.99, fleshy: ≥ 6), and calf sex on colostrum yield (single-quarter colostrum weight) and quality. Pearson correlation coefficients were also determined for colostrum yield with dam pre-calving body weight (BW), calf birth weight, calf birth weight relative to dam BW, whole placental dry weight, and gestation length. Mature dams had the greatest (P ≤ 0.03) and primiparous dams had the least (P ≤ 0.001) colostrum yield and total lactose. Colostrum from primiparous dams had greater (P = 0.03) IgG concentration than mature and greater (P ≤ 0.001) protein concentration than young and mature. Mature dams had greater (P ≤ 0.02) total IgG, total protein, and total triglycerides compared with both primiparous and young. Colostrum yield was less (P ≤ 0.04) for thin than moderate and fleshy dams. Total IgG was unaffected (P = 0.11) by dam BCS; however, thin dams had greater (P ≤ 0.04) IgG concentration than moderate and fleshy. Lactose concentration and total lactose were less (P ≤ 0.02) in colostrum from thin compared with moderate dams. Protein concentration was greater (P = 0.001) in thin than moderate dams, but thin dams had less (P ≤ 0.02) total protein compared with moderate and fleshy. Dam BCS did not affect (P ≥ 0.59) colostrum triglyceride concentration or total triglycerides. Colostrum yield and quality were not affected (P ≥ 0.22) by calf sex. Pre-calving dam BW was positively correlated with colostrum yield (r = 0.46, P < 0.001). Colostrum yield was also positively correlated with calf birth weight (r = 0.31, P < 0.001) and whole placental dry weight (r = 0.26, P = 0.007), but tended to be negatively correlated with calf birth weight relative to dam BW (r = -0.14, P = 0.09). Gestation length had no relationship (P = 0.31) with colostrum yield. Overall, colostrum yield and quality are negatively affected in young and thin beef dams. In addition, both dam and calf weight have positive relationships with colostrum yield, likely mediated by endocrine action associated with placental size.

中文翻译：

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109 母牛和犊牛对肉牛初乳产量和品质的影响


为了确定影响初乳产量和质量的因素，将 6 次实验中 148 对奶牛-犊牛的数据合并在一起。在每个实验中，单个后四分之一初乳产量是在产犊后但哺乳前获得的。通过 ELISA 测定初乳 IgG，通过比色分析测定初乳乳糖、甘油三酯（作为总脂肪的量度）和蛋白质。总 IgG 和营养物质的计算方法是浓度乘以单季度产量。还在产犊后收集犊牛出生体重和排出的胎盘干重。采用混合线性模型（实验为随机效应）确定母牛年龄（初产：2 岁，幼崽：3 至 4 岁，成熟：≥ 5 岁）、母猪围产期体况评分（BCS;瘦：< 5，中等：5 至 5.99，肉质：≥ 6）和犊牛性别对初乳产量（单四分之一初乳重量）和质量的影响。还确定了初乳产量与母牛产犊前体重 （BW）、犊牛出生体重、犊牛相对于母牛 BW 的出生体重、整个胎盘干重和妊娠长度的 Pearson 相关系数。成熟母猪的初乳产量和总乳糖产量最低 （P ≤ 0.03），初产母猪初乳产量和总乳糖≤最低。初产母猪的初乳 IgG 浓度高于成熟 （P = 0.03），蛋白浓度高于 （P ≤ 0.001） 幼龄和成熟。与初产母和幼母相比，成熟母猪的总 IgG 、总蛋白和总甘油三酯更高 （P ≤ 0.02）。薄母猪的初乳产量低于中等和肉质母猪 （P ≤ 0.04）。总 IgG 不受母 BCS 的影响 （P = 0.11）;然而，薄母猪的 IgG 浓度高于 （P ≤ 0.04） 比中等和肉质的 IgG 浓度高。乳糖浓度和总乳糖较低 （P ≤ 0。02） 与中等分株相比，薄初乳。瘦母猪的蛋白质浓度高于中度母鸡 （P = 0.001），但与中度母猪和肉质母猪相比，薄母猪的总蛋白质含量较低 （P ≤ 0.02）。Dam BCS 不影响 （P ≥ 0.59） 初乳甘油三酯浓度或总甘油三酯。初乳产量和质量不受犊牛性别的影响 （P ≥ 0.22）。产犊前母猪 BW 与初乳产量呈正相关 （r = 0.46，P < 0.001）。初乳产量也与犊牛出生体重 （r = 0.31， P < 0.001） 和整个胎盘干重 （r = 0.26， P = 0.007） 呈正相关，但与犊牛相对于母牛 BW 的出生体重呈负相关 （r = -0.14， P = 0.09）。妊娠长度与初乳产量没有关系 （P = 0.31）。总体而言，年轻而瘦的牛肉母牛的初乳产量和质量受到负面影响。此外，母牛和犊牛的体重都与初乳产量呈正相关，这可能是由与胎盘大小相关的内分泌作用介导的。