Data from: Maternal nutrition during pregnancy affects testicular and bone development, glucose metabolism and response to overnutrition in weaned horses up to two years

Pregnant mares and post-weaning foals are often fed concentrates rich in soluble carbohydrates, together with forage. Recent studies suggest that the use of concentrates is linked to alterations of metabolism and the development of osteochondrosis in foals. The aim of this study was to determine if broodmare diet during gestation affects metabolism, osteoarticular status and growth of yearlings overfed from 20 to 24 months of age and/or sexual maturity in prepubertal colts. Twenty-four saddlebred mares were fed forage only (n=12, group F) or cracked barley and forage (n=12, group B) from mid-gestation until foaling. Colts were gelded at 12 months of age. Between 20 and 24 months of age, all yearlings were overfed (+140% of requirements) using an automatic concentrate feeder. Offspring were monitored for growth between 6 and 24 months of age, glucose homeostasis was evaluated via modified frequently sampled intra veinous glucose tolerance test (FSIGT) at 19 and 24 months of age and osteoarticular status was investigated using radiographic examinations at 24 months of age. The structure and function of testicles from prepubertal colts were analyzed using stereology and RT-qPCR. Post-weaning weight growth was not different between groups. Testicular maturation was delayed in F colts compared to B colts at 12 months of age. From 19 months of age, the cannon bone was wider in B vs F yearlings. F yearlings were more insulin resistant at 19 months compared to B yearlings but B yearlings were affected more severely by overnutrition with reduced insulin sensitivity. The osteoarticular status at 24 months of age was not different between groups. In conclusion, nutritional management of the pregnant broodmare and the growing foal may affect sexual maturity of colts and the metabolism of foals until 24 months of age. These effects may be deleterious for reproductive and sportive performances in older horses.

妊娠母马与断奶后幼驹通常会与饲草一同饲喂富含可溶性碳水化合物的精饲料。近期研究表明，精饲料的使用与幼驹的代谢改变及骨软骨病（osteochondrosis）的发生存在关联。本研究旨在探究妊娠期间种母马的日粮是否会影响20至24月龄期间被过度饲喂的周岁驹的代谢、骨关节状态与生长，以及青春期前公驹的性成熟情况。本研究共纳入24头萨德勒马（Saddlebred）母马，自妊娠中期至产驹期间，分别仅饲喂饲草（F组，n=12）或饲喂破碎大麦与饲草（B组，n=12）。公驹于12月龄时去势。在20至24月龄期间，所有周岁驹均通过自动精饲料饲喂器进行过度饲喂（饲喂量为营养需求的140%）。研究人员对后代驹在6至24月龄期间的生长情况进行监测；分别于19和24月龄时，通过改良频繁采样静脉葡萄糖耐量试验（modified frequently sampled intravenous glucose tolerance test, FSIGT）评估葡萄糖稳态；并于24月龄时通过放射影像学检查探究其骨关节状态。采用体视学技术与实时定量聚合酶链式反应（RT-qPCR）分析青春期前公驹的睾丸结构与功能。断奶后的体重增长在两组间无显著差异。与B组公驹相比，12月龄时F组公驹的睾丸成熟延迟。自19月龄起，B组周岁驹的管骨（cannon bone）更宽。与B组周岁驹相比，19月龄时F组周岁驹的胰岛素抵抗更为显著；但B组周岁驹因营养过度受影响更严重，表现为胰岛素敏感性降低。24月龄时两组的骨关节状态无显著差异。综上，妊娠种母马的营养管理与生长中幼驹的日粮，可能会影响公驹的性成熟以及24月龄前幼驹的代谢状态。此类效应可能对老龄马的繁殖与运动性能产生不利影响。