Department of Animal Sciences,College of Agriculture,Isfahan University of Technology,PO Box 84156,Isfahan,Iran.
Animal. 2018 Mar;12(3):617-623. doi: 10.1017/S1751731117002026. Epub 2017 Aug 14.
Stillbirth is an economically important trait on dairy farms. Knowledge of the consequences of, and the economic losses associated with stillbirth can help the producer when making management decisions. The objectives of this study were to determine the effects of stillbirth on productive and reproductive performance as well as financial losses due to stillbirth incidence in Iranian Holstein dairy farms. Economic and performance data were collected from nine Holstein dairy farms in Isfahan and Khorasan provinces of Iran from March 2008 to December 2013. The final data set included 160 410 calving records from 53 265 cows. A linear mixed model was developed to evaluate the effects of stillbirth on performance of primiparous and multiparous cows separately and overall. An economic model was used to estimate the economic losses due to stillbirth. The incidence of stillbirth cases per cow per year was 4.2% on average (3.4% to 6.8% at herd level). The least square means results showed that a case of stillbirth significantly (P0.05). Overall, a case of stillbirth reduced 305-day milk yield by 544.0±76.5 kg/cow per lactation. Stillbirth had no significant effects on 305-day fat and protein percentages in either primiparous or multiparous cows. Overall, cows that gave birth to stillborn calves had significantly increased days open by 14.6±2.6 days and the number of inseminations per conception by 0.2 compared with cows that gave birth to live calves (P<0.01). In general, the negative productive and reproductive effects associated with stillbirth were smaller and non-significant for primiparous cows compared with multiparous cows. The financial losses associated with stillbirth incidence averaged US$ 938 per case (range from $US 767 to $US 1189 in the nine investigated farms). The loss of a calf was not the only cost associated with stillbirth, as it accounted for 71.0% of the total cost. The costs of dystocia (7.6%) and culling and replacement expenses (6.3%) were the next most important costs associated with stillbirth. These results can be used to assess the potential return from management strategies to reduce the occurrence of stillbirths.
死产是奶牛场具有重要经济意义的特征。了解死产的后果以及与死产发生率相关的经济损失，可以帮助生产者在做出管理决策时做出决策。本研究的目的是确定死产对生产和繁殖性能的影响，以及由于伊朗荷斯坦奶牛场的死产发生率而导致的经济损失。2008 年 3 月至 2013 年 12 月，从伊朗伊斯法罕省和霍拉桑省的 9 个荷斯坦奶牛场收集了经济和性能数据。最终数据集包括 53265 头奶牛的 160410 次产犊记录。建立了一个线性混合模型，分别和总体上评估死产对初产牛和经产牛性能的影响。使用经济模型估计死产造成的经济损失。平均而言，每头奶牛每年每头奶牛的死产病例为 4.2%（牛群水平为 3.4%至 6.8%）。最小二乘均值结果表明，死产病例显著（P<0.05）。总的来说，死产使每头奶牛的 305 天产奶量减少了 544.0±76.5 公斤/头。死产对初产牛和经产牛的 305 天脂肪和蛋白质百分比均无显著影响。总的来说，与产活犊牛的奶牛相比，产死犊牛的奶牛的开放天数增加了 14.6±2.6 天，配种受胎率增加了 0.2 次/配种（P<0.01）。一般来说，与经产牛相比，初产牛与死产相关的生产和繁殖的负面影响较小且不显著。在 9 个调查农场中，每例死产的经济损失平均为 938 美元（范围为 767 美元至 1189 美元）。死产不仅仅是与死产相关的成本，它占总成本的 71.0%。难产（7.6%）和淘汰和替代费用（6.3%）是与死产相关的第二大重要成本。这些结果可用于评估从管理策略中获得的潜在回报，以减少死产的发生。
