Beiranvand Hamed, Mahnani Abolfazl, Kahyani Ali, Dunshea Frank R, Ahmadi Farhad
R&D Department of Chaltasian & Talise Asil Jahan Agro-Animal Husbandry, Varamin 33751-13111, Iran.
Department of Animal Sciences, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Animals (Basel). 2024 Oct 21;14(20):3040. doi: 10.3390/ani14203040.
A suboptimal intrauterine environment during gestation may result in the programming of long-lasting structural and physiological alterations in the developing fetus, leading to health and production complications in adulthood. This observational study aimed to identify the impact of exposure to the summer season at different trimesters of gestation, dam parity, and their interaction on the postpartum disease incidence, first-lactation milk production, and herd lifespan of the offspring (F generation). Using a dataset collected from two commercial herds, the female offspring were categorized into three groups based on the trimester their dams experienced summer season during pregnancy: (1) first trimester (n = 2345), (2) second trimester (n = 3513), and (3) final trimester (n = 4988). The estimated 305-day milk production was lower in daughters (as a first-lactation cow) born to dams exposed to summer season during the first vs. third trimester. Summer season exposure during the first vs. third trimester resulted in the offspring that were less likely to remain in the herd (hazard ratio = 0.90; 95% CI = 0.84-0.95). Daughters of parous vs. nulliparous dams were more likely to experience dystocia and metritis but less likely to experience retained placenta. The risk of culling was higher in daughters of parous vs. nulliparous dams. Our preliminary findings suggest that the first trimester is a critical determinant of the female progeny's future productive performance and survivability. Dam parity was also identified as an influential factor affecting offspring health, as dystocia and metritis were more prevalent, and the culling risk was greater in daughters born to parous dams.
孕期子宫内环境欠佳可能会导致发育中的胎儿出现长期的结构和生理改变，进而引发成年后的健康和生产问题。这项观察性研究旨在确定妊娠不同阶段暴露于夏季、母体胎次及其相互作用对后代（F代）产后疾病发病率、头胎泌乳量和畜群寿命的影响。利用从两个商业畜群收集的数据集，根据其母体在孕期经历夏季的阶段，将雌性后代分为三组：（1）孕早期（n = 2345），（2）孕中期（n = 3513），以及（3）孕晚期（n = 4988）。与在孕晚期相比，在孕早期暴露于夏季的母体所生的女儿（作为头胎母牛），其估计的305天泌乳量较低。与在孕晚期相比，在孕早期暴露于夏季会导致后代留在畜群中的可能性降低（风险比 = 0.90；95%置信区间 = 0.84 - 0.95）。经产母体与初产母体所生的女儿更易发生难产和子宫炎，但发生胎盘滞留的可能性较小。经产母体与初产母体所生的女儿被淘汰的风险更高。我们的初步研究结果表明，孕早期是雌性后代未来生产性能和生存能力的关键决定因素。母体胎次也被确定为影响后代健康的一个因素，因为难产和子宫炎在经产母体所生的女儿中更为普遍，且被淘汰的风险更大。
