Birth weight threshold for identifying piglets at risk for preweaning mortality
Birth weight threshold for identifying piglets at risk for preweaning mortality
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DOI：
10.1093/tas/txz076
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发表时间：
2019-03-01
影响因子：
1.3
通讯作者：
Ritter, Matthew J.
中科院分区：
文献类型：
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作者：
Feldpausch, Julie A.;Jourquin, Jan;Ritter, Matthew J.
多项研究表明仔猪出生体重和断奶前死亡率之间存在重要关系。因此，当前工作的目标是确定断奶前死亡率的出生体重阈值。两项研究的出生体重和存活数据进行了汇总、多研究分析，涉及四个商业农场（三个欧洲，一个美国）的 394 窝仔猪，总共 4,068 头仔猪。两项研究的总体断奶前死亡率为 12.2%。分析中使用的关键变量是仔猪出生体重（出生后 24 小时内测量）以及 3-4 周龄断奶时相应的存活结果（死或活）。混合效应逻辑回归模型适合估计断奶前死亡率和出生体重之间的关系。纳入研究的随机效应是为了解释两项研究之间死亡率的总体差异。选择分段线性预测因子来最好地代表当出生体重增加0.5-1.0公斤范围内断奶前死亡率的急剧下降以及体重超过1.0公斤时较不极端的变化。出生体重和断奶前死亡率模型的变化点是通过比较基于最大化0.5至2.3公斤出生体重区间内的可能性的模型拟合来确定的。分析结果显示，出生体重与断奶前死亡率之间存在曲线关系，出生体重变化点值或阈值为1.11 kg。在合并数据集中，15.2% 的猪具有出生体重
Several studies have suggested there is a critical relationship between piglet birth weight and preweaning mortality. Thus, the objective of the current work was to identify a birth weight threshold value for preweaning mortality. Birth weight and survival data from two studies involving a combined total of 4,068 piglets from 394 litters on four commercial farms (three European, one U.S.) were compiled for a pooled, multistudy analysis. Overall preweaning mortality across the two studies was 12.2%. Key variables used in the analysis were piglet birth weight (measured within 24 h of birth) and corresponding survival outcome (dead or live) by weaning at 3-4 wk of age. A mixed effects logistic regression model was fit to estimate the relationship between preweaning mortality and birth weight. A random effect of study was included to account for overall differences in mortality between the two studies. A piecewise linear predictor was selected to best represent the drastic decrease in preweaning mortality found as birth weight increased in the range of 0.5-1.0 kg and the less extreme change in weight above 1.0 kg. The change point of the birth weight and preweaning mortality model was determined by comparing model fit based on maximizing the likelihood over the interval ranging from 0.5 to 2.3 kg birth weight. Results from the analysis showed a curvilinear relationship between birth weight and preweaning mortality where the birth weight change point value or threshold value was 1.11 kg. In the combined data set, 15.2% of pigs had birth weights