Department of Pathology, Theriogenology, and One Healthy, School of Agricultural and Veterinarian Sciences (FCAV), São Paulo State University (UNESP), Via de Acesso Prof.Paulo Donato Castellane, Jaboticabal, SP, 14884-900, Brazil.
Department of Animal Reproduction, School of Veterinary Medicine and Animal Science School of Veterinary Medicine and Animal Science, USP - University of São Paulo, 87, Prof. Dr. Orlando Marques de Paiva Avenue, Cidade Universitária, São Paulo, SP, 05508-270, Brazil.
Theriogenology. 2024 Dec;230:107-114. doi: 10.1016/j.theriogenology.2024.09.003. Epub 2024 Sep 10.
Glucose metabolism adapts to gestation, resulting in progressive physiological insulin resistance and increased insulin secretion to maintain maternal euglycemia and glucose availability for the developing fetus. These changes can impact mare fertility and maternal and neonatal health. This is the first comparison of body condition, regional adiposity, insulin and glucose dynamics, lipid metabolism, and cytokine production between lactating and non-lactating mares before, during pregnancy, and early postpartum. Twelve pregnancies from 9 broodmares, five nonlactating (NL) and seven lactating (L), were used. Evaluations were performed on the day of ovulation, at 55, 110, 165, 220, 275, and 330 days of gestation (D55, D110, D165, D220, D275, D330) and 21 days postpartum (21pp). Mares in the L group had lower basal insulin and glucose at the beginning of pregnancy, smaller area under the curve of insulin and glucose, and greater insulin sensitivity and glucose tolerance. Resistin was higher in D110 and D165 than in D0, D275, 330 and 21pp, while leptin was higher in D55, and in D110, at D110 it was equal to D0, D220, and D275, but higher than at D330 and D21pp. As for the groups, L presented lower body condition score (BCS), crest neck score (CNS), rump fat thickness (RUM), basal insulin, glucose area under the curve (AUCg), MIRG and higher RISQI, adiponectin and tumor necrosis factor (TNFα). There was no effect over time in non-esterified fatty acids (NEFA) concentrations between the L mares; in the NL, D275 presented higher concentrations than those of D0, D55, and D110, which in turn were equal to the other time points; there were higher concentrations in NL mares than L in samples D165 and D275. In conclusion, a different metabolic profile during pregnancy was detected, and NL mares were closer to the metabolic threshold for the occurrence of metabolic syndrome during pregnancy. Understanding the impacts of these differences on mare's health and their offspring's future is fundamental as most of our recipient mares for embryo transfer are non-lactating. Therefore, we suggest that further studies be performed to evaluate lactation's influence on mares' metabolic parameters.
葡萄糖代谢适应妊娠，导致进行性生理性胰岛素抵抗和胰岛素分泌增加，以维持母体血糖正常和葡萄糖供应给发育中的胎儿。这些变化可能会影响母马的生育能力以及母马和新生儿的健康。这是首次比较哺乳期和非哺乳期母马在妊娠前、妊娠中和产后早期的身体状况、局部肥胖、胰岛素和葡萄糖动态、脂质代谢和细胞因子产生。从 9 匹母马中选择了 12 个妊娠，5 个非哺乳期（NL）和 7 个哺乳期（L）。在排卵日、妊娠 55、110、165、220、275 和 330 天（D55、D110、D165、D220、D275、D330）和产后 21 天（21pp）进行评估。L 组母马在妊娠开始时基础胰岛素和血糖较低，胰岛素和血糖曲线下面积较小，胰岛素敏感性和葡萄糖耐量较大。妊娠 110 和 165 时抵抗素高于 D0、D275、330 和 21pp，而瘦素在 D55 时较高，在 D110 时与 D0、D220 和 D275 相等，但高于 D330 和 D21pp。就组而言，L 呈现较低的身体状况评分（BCS）、颈嵴评分（CNS）、臀部脂肪厚度（RUM）、基础胰岛素、血糖曲线下面积（AUCg）、MIRG 和较高的 RISQI、脂联素和肿瘤坏死因子（TNFα）。哺乳期母马的非酯化脂肪酸（NEFA）浓度在不同时间点之间没有变化；在非哺乳期，D275 的浓度高于 D0、D55 和 D110，而 D110 与其他时间点相等；D165 和 D275 时非哺乳期母马的浓度高于哺乳期母马。总之，检测到妊娠期间不同的代谢谱，而非哺乳期母马更接近妊娠期间发生代谢综合征的代谢阈值。了解这些差异对母马健康及其后代未来的影响至关重要，因为我们大多数胚胎移植的受体母马都是非哺乳期的。因此，我们建议进一步研究以评估哺乳期对母马代谢参数的影响。
