Department of Animal Sciences, College of Agriculture, Isfahan University of Technology, PO Box, 84156-83111, Isfahan, Iran.
Department of Animal Sciences, College of Agriculture, Isfahan University of Technology, PO Box, 84156-83111, Isfahan, Iran.
Theriogenology. 2021 Nov;175:61-68. doi: 10.1016/j.theriogenology.2021.08.036. Epub 2021 Sep 3.
Retained placenta (RP) is as an important reproductive disorder which adversely affects the economic performance of dairy cows. Understanding the consequences and economic losses associated with RP can persuade dairy farmers to consider it more effectively in their management decisions. Hence, the aims of this research were to assess the effect of RP on production and reproduction attributes as well as economic losses in Iranian Holstein cows. The data was collected from nine Holstein dairy herds in Isfahan province of Iran. The final dataset comprised of 139,508 records of 58,086 cows which calved between March 2011 and December 2018. A linear mixed model was developed to evaluate the effect of RP on individual performance of primiparous and multiparous cows. The economic losses associated with the RP were finally estimated. The average incidence of RP per cow over a year was 12.3% (ranged between 9.0 and 15.4%). Each incidence of RP significantly reduced milk, fat and protein yields in primiparous and multiparous cows (P < 0.05). The adverse effect of RP on the milk production was much higher in the cows at the early phase of lactation (i.e. 100-d lactation group) than the cows in mid or late lactation. The estimated production losses (±standard deviation) due to the RP event were 282.1 ± 43.0 and 295.7 ± 40.8 kg per cow for a 305-d lactation period in primiparous and multiparous cows, respectively. However, the fertility performance was less affected by the RP in primiparous compared to multiparous cows. The average of days open increased by 8.3 ± 5.3 and 19.8 ± 7.1 d in primiparous and multiparous cows, respectively. The financial losses associated with RP were on average US$ 350.4 and US$ 481.2 per incidence in primiparous and multiparous cows, respectively, ranged from US$ 311.9 to 456.2 depending on the parity number (primi- or multiparous) and herd management. The highest financial losses due to RP were associated with reduction in milk production (38.5% of total loss) and low fertility (28.5% of total loss) had the highest contribution in in primiparous and multiparous cows, respectively. The results of our research highlight the economic importance of improved calving management to reduce RP occurrence in dairy cows.
胎盘滞留（RP）是一种重要的生殖障碍，会对奶牛的经济效益产生不利影响。了解与 RP 相关的后果和经济损失，可以促使奶牛养殖者在管理决策中更有效地考虑这一问题。因此，本研究旨在评估 RP 对伊朗荷斯坦奶牛生产和繁殖性能以及经济损失的影响。数据来自伊朗伊斯法罕省的 9 个荷斯坦奶牛场。最终数据集包括 58086 头奶牛的 139508 条记录，这些奶牛在 2011 年 3 月至 2018 年 12 月间分娩。采用线性混合模型评估 RP 对初产和经产奶牛个体性能的影响。最后估算了与 RP 相关的经济损失。奶牛每年的平均 RP 发生率为 12.3%（范围为 9.0%至 15.4%）。RP 的每次发生都会显著降低初产和经产奶牛的牛奶、脂肪和蛋白质产量（P<0.05）。RP 对泌乳早期（即 100 天泌乳组）奶牛产奶量的不利影响明显高于泌乳中期或后期的奶牛。由于 RP 事件导致的估计产量损失（±标准偏差）分别为初产奶牛和经产奶牛 305 天泌乳期的 282.1±43.0 和 295.7±40.8kg/头。然而，与经产奶牛相比，初产奶牛的繁殖性能受 RP 的影响较小。初产和经产奶牛的平均空怀天数分别增加了 8.3±5.3 和 19.8±7.1 天。RP 导致的经济损失平均分别为初产和经产奶牛每例 350.4 美元和 481.2 美元，范围分别为 311.9 美元至 456.2 美元，具体取决于胎次（初产或经产）和牛群管理。由于产奶量下降（占总损失的 38.5%）和繁殖力低下（占总损失的 28.5%）导致的 RP 相关经济损失最高，分别占初产和经产奶牛的最高比例。本研究结果强调了通过改善分娩管理来减少奶牛 RP 发生的重要性。
