Impact of hyperketonemia in early lactation dairy cows on health and production

作者：T.F. Duffield, Kerry D. Lissemore, B.W. McBride, Ken E. Leslie · 发表于：Journal of Dairy Science · 年份：2009 · DOI：10.3168/jds.2008-1507 · 被引用次数：753 · 研究领域：Reproductive Physiology in Livestock、Ruminant Nutrition and Digestive Physiology、Genetic and phenotypic traits in livestock

Data from 1,010 lactating lactating, predominately component-fed Holstein cattle from 25 predominately tie-stall dairy farms in southwest Ontario were used to identify objective thresholds for defining hyperketonemia in lactating dairy cattle based on negative impacts on cow health, milk production, or both. Serum samples obtained during wk 1 and 2 postpartum and analyzed for beta-hydroxybutyrate (BHBA) concentrations that were used in analysis. Data were time-ordered so that the serum samples were obtained at least 1 d before the disease or milk recording events. Serum BHBA cutpoints were constructed at 200 micromol/L intervals between 600 and 2,000 micromol/L. Critical cutpoints for the health analysis were determined based on the threshold having the greatest sum of sensitivity and specificity for predicting the disease occurrence. For the production outcomes, models for first test day milk yield, milk fat, and milk protein percentage were constructed including covariates of parity, precalving body condition score, season of calving, test day linear score, and the random effect of herd. Each cutpoint was tested in these models to determine the threshold with the greatest impact and least risk of a type 1 error. Serum BHBA concentrations at or above 1,200 micromol/L in the first week following calving were associated with increased risks of subsequent displaced abomasum [odds ratio (OR) = 2.60] and metritis (OR = 3.35), whereas the critical threshold of BHBA in wk 2 postpar...