Abstract：
This study investigated the effects of negative energy balance (NEB) on perinatal ewes, with a focus on changes in growth performance, serum biochemical parameters, rumen fermentation, ruminal bacteria composition, placental phenotype-related indicators, and expression levels of genes related to placental function. Twenty ewes at 130 days of gestation were randomly allocated to either the positive energy balance (PEB) or NEB groups. In the experiment, ewes in the PEB group were fed the same amount as their intake during the pre-feeding baseline period, while ewes in the NEB group were restricted to 70% of their individual baseline feed intake. The experiment was conducted until 42 days postpartum, and five double-lamb ewes per group were selected for slaughter. The results demonstrated that NEB led to a significant decrease in body weight, carcass weight, and the birth and weaning weights of lambs (P < 0.05). Additionally, NEB caused alterations in serum biochemical parameters, such as increased non-esterified fatty acids and β-hydroxybutyrate levels and decreased cholesterol and albumin levels (P < 0.05). Rumen fermentation and epithelial parameters were also affected, with a reduction in the concentrations of acetic acid, butyric acid, total acid and a decrease in the length of the rumen papilla (P < 0.05). Moreover, NEB induced changes in the structure and composition of ruminal bacteria, with significant differences in α-diversity indices and rumen microbial community composition (P < 0.05). Gene expression in rumen papilla and ewe placenta was also affected, impacting genes associated with glucose and amino acid transport, proliferation, apoptosis, and angiogenesis (P < 0.05). These findings screened the key microbiota in the rumen of ewes following NEB and highlighted the critical genes associated with rumen function. Furthermore, this study revealed the impact of NEB on placental function in ewes, providing a foundation for investigating how nutrition in ewes influences reproductive performance. This research demonstrates how nutrition regulates reproductive performance by considering the combined perspectives of rumen microbiota and placental function.
摘要：
这项研究调查了负能量平衡（NEB）对围产期母羊的影响，关注增长绩效的变化，血清生化参数，瘤胃发酵，瘤胃细菌组成，胎盘表型相关指标，和胎盘功能相关基因的表达水平。将妊娠130天的20只母羊随机分配到正能量平衡（PEB）或NEB组。在实验中,PEB组的母羊在饲喂前的基线期间饲喂与它们的摄入量相同的量，而NEB组的母羊被限制在其个体基线采食量的70%。实验一直进行到产后42天,每组选择五只双羊母羊进行屠宰。结果表明，NEB导致体重显着下降，屠体重量,羔羊的出生和断奶重量（P<0.05）。此外,NEB引起血清生化指标的改变，如非酯化脂肪酸和β-羟基丁酸水平升高，胆固醇和白蛋白水平降低（P<0.05）。瘤胃发酵和上皮参数也受到影响，随着乙酸浓度的降低，丁酸,总酸和瘤胃乳头长度减少（P<0.05）。此外，NEB诱导瘤胃细菌结构和组成的变化，α-多样性指数和瘤胃微生物群落组成差异显著(P<0.05)。瘤胃乳头和母羊胎盘中的基因表达也受到影响，影响与葡萄糖和氨基酸转运相关的基因，扩散,凋亡，血管生成(P<0.05)。这些发现筛选了NEB后母羊瘤胃中的关键微生物群，并强调了与瘤胃功能相关的关键基因。此外，这项研究揭示了NEB对母羊胎盘功能的影响，为调查母羊的营养如何影响繁殖性能提供了基础。这项研究通过考虑瘤胃微生物群和胎盘功能的综合观点来证明营养如何调节生殖性能。
