Torsein Maria, Lindberg Ann, Svensson Catarina, Jensen Sören Krogh, Berg Charlotte, Waller Karin Persson
Farm & Animal Health, Uddetorp Röda huset, 532 96, Skara, Sweden.
Department of Animal Environment and Health, Swedish University of Agricultural Sciences, P.O. Box 234, 532 23, Skara, Sweden.
Acta Vet Scand. 2018 Feb 1;60(1):7. doi: 10.1186/s13028-018-0361-0.
A study of herd-level risk factors for calf mortality in large Swedish dairy herds showed low serum concentrations of α-tocopherol and β-carotene in 1-7 day old calves to be more common in high mortality herds. Therefore, we aimed to investigate if calf mortality risk at herd level is associated with concentrations of α-tocopherol and/or β-carotene at individual level in feed, colostrum, cow and calf serum, while controlling for herd level covariates. Inclusion criteria were affiliation to the Swedish official milk recording scheme, herd size of ≥ 120 milking cows/year, calf mortality risk (day 1-90) of at least 6% (high mortality; HM) or less than 1% (low mortality; LM) and located within one of two regions in southern Sweden. This cross-sectional study was performed in 2010 in 19 (n = 9; n = 10) dairy herds. Questionnaires were used to collect information about feed and routines for colostrum feeding. Feed (n = 57), colostrum (n = 162), cow serum (n = 189) and calf serum samples (n = 187) were collected and analysed for α-tocopherol and β-carotene. Other analyses e.g. total serum protein, fat content, and total solids in colostrum were also performed. Linear regression models with vitamin concentrations in feed, colostrum, cow and calf serum as outcome were performed.
Calves in HM herds had lower concentrations of α-tocopherol in serum than calves in LM herds, but the effect depended on total protein status in serum of the calf (P = 0.036). Calves from herds that fed transition milk for 3 days or more had higher α-tocopherol concentrations in serum than calves from herds feeding transition milk up to 2 days (P = 0.013). Fat percentage in colostrum was positively associated with α-tocopherol (P < 0.001) and β-carotene concentrations in colostrum (P < 0.001). A diet containing ≥ 20% (in kg dry matter) maize silage of the total ration was negatively associated with β-carotene concentration in cow serum (P = 0.001).
High calf mortality risks were associated with lower concentrations of α-tocopherol in calf serum for calves with failure of passive transfer. Feeding transition milk longer was associated with higher concentrations of α-tocopherol in calf serum. In HM herds, evaluation of the calves' α-tocopherol status is recommended.
一项针对瑞典大型奶牛场犊牛死亡率群体水平风险因素的研究表明，1至7日龄犊牛血清中α-生育酚和β-胡萝卜素浓度较低在高死亡率牛群中更为常见。因此，我们旨在研究在控制群体水平协变量的同时，群体水平的犊牛死亡风险是否与饲料、初乳、母牛和犊牛血清中个体水平的α-生育酚和/或β-胡萝卜素浓度相关。纳入标准为隶属于瑞典官方牛奶记录计划、牛群规模≥120头泌乳奶牛/年、犊牛死亡风险（第1至90天）至少为6%（高死亡率；HM）或低于1%（低死亡率；LM）且位于瑞典南部两个地区之一。这项横断面研究于2010年在19个（n = 9；n = 10）奶牛场进行。通过问卷调查收集有关饲料和初乳喂养常规的信息。收集饲料（n = 57）、初乳（n = 162）、母牛血清（n = 189）和犊牛血清样本（n = 187）并分析其中的α-生育酚和β-胡萝卜素。还进行了其他分析，例如初乳中的总血清蛋白、脂肪含量和总固体含量。以饲料、初乳、母牛和犊牛血清中的维生素浓度为结果进行线性回归模型分析。
HM牛群中的犊牛血清中α-生育酚浓度低于LM牛群中的犊牛，但这种影响取决于犊牛血清中的总蛋白状态（P = 0.036）。喂食过渡乳3天或更长时间的牛群中的犊牛血清中α-生育酚浓度高于喂食过渡乳最多2天的牛群中的犊牛（P = 0.013）。初乳中的脂肪百分比与初乳中的α-生育酚（P < 0.001）和β-胡萝卜素浓度（P < 0.001）呈正相关。日粮中玉米青贮料占总日粮（以干物质计）≥20%与母牛血清中β-胡萝卜素浓度呈负相关（P = 0.001）。
对于被动转运失败的犊牛，高犊牛死亡风险与犊牛血清中较低的α-生育酚浓度相关。较长时间喂食过渡乳与犊牛血清中较高的α-生育酚浓度相关。在HM牛群中，建议评估犊牛的α-生育酚状态。
