Impact of hyperketonemia in early lactation dairy cows on health and production
Impact of hyperketonemia in early lactation dairy cows on health and production
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DOI：
10.3168/jds.2008-1507
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发表时间：
2009-02-01
影响因子：
3.5
通讯作者：
Leslie, K. E.
中科院分区：
文献类型：
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作者：
Duffield, T. F.;Lissemore, K. D.;Leslie, K. E.
来自安大略西南部25个主要是扎栏奶牛场的1，010头泌乳期泌乳、主要是成分喂养的荷斯坦牛的数据用于确定基于对奶牛健康、产奶量或两者的负面影响来定义泌乳期奶牛高酮血症的客观阈值。在产后第1周和第2周采集血清样本，并分析用于分析的β-羟基丁酸酯（BHBA）浓度。数据按时间顺序排列，以便在疾病或乳汁记录事件前至少1天获得血清样品。在600和2，000 μ mol/L之间以200 μ mol/L间隔构建血清BHBA临界点。根据预测疾病发生的灵敏度和特异性之和最大的阈值确定健康分析的临界点。对于生产结果，构建了第一个测试日产奶量、乳脂和乳蛋白百分比的模型，包括胎次、产犊前身体状况评分、产犊季节、测试日线性评分和牛群随机效应的协变量。在这些模型中检测每个临界点，以确定具有最大影响和最小1类错误风险的阈值。产犊后第1周血清BHBA浓度≥ 1，200 μ mol/L与随后皱胃移位[比值比（OR）= 2.60]和子宫炎（OR = 3.35）的风险增加相关，而产后第2周BHBA对皱胃移位风险的临界阈值为≥ 1，800 μ mol/L（OR = 6.22）。从产后第1周和第2周获得的血清中预测随后临床酮症风险的最佳阈值为1，400 μ mol/L BHBA（OR分别为4.25和5.98）。产后第1周或第2周，临床型乳腺炎与血清BHBA升高之间无相关性，产后第2周BHBA与子宫炎风险之间无相关性。产犊后第一周和第二周测得的血清BHBA水平越高，泌乳期第一个奶牛群改善试验日的产奶量越低，乳脂率越高，乳蛋白率越低。对第一个奶牛群的影响改良试验产奶量从BHBA = 1，200 μ mol/L（第1周样品）和= 1，400 μ mol/L（第2周样品）开始。产犊后第一周和第二周血清浓度分别为1，400 μ mol/L（-1.88 kg/d）和2，000 μ mol/L（-3.3 kg/d）时，对产量的影响最大。高酮血症可定义为1，400 μ mol/L的BHBA，在产后的前2周内增加疾病风险，并导致泌乳早期产奶量的大量损失。
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 mu mol/L intervals between 600 and 2,000 mu mol/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 mu mol/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 postpartum on the risk of abomasal displacement was = 1,800 mu mol/L (OR = 6.22). The best threshold for predicting subsequent risk of clinical ketosis from serum obtained during wk 1 and wk 2 postpartum was 1,400 mu mol/L of BHBA (OR = 4.25 and 5.98, respectively). There was no association between clinical mastitis and elevated serum BHBA in wk 1 or 2 postpartum, and there was no association between wk 2 BHBA and risk of metritis. Greater serum BHBA measured during the first and second week postcalving were associated with less milk yield, greater milk fat percentage, and less milk protein percentage on the first Dairy Herd Improvement test day of lactation. Impacts on first Dairy Herd Improvement test milk yield began at BHBA = 1,200 mu mol/L for wk 1 samples and = 1,400 mu mol/L for wk 2 samples. The greatest impact on yield occurred at 1,400 mu mol/L (- 1.88 kg/d) and 2,000 mu mol/L (- 3.3 kg/d) for sera from the first and second week postcalving, respectively. Hyperketonemia can be defined at 1,400 mu mol/L of BHBA and in the first 2 wk postpartum increases disease risk and results in substantial loss of milk yield in early lactation.