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.妊娠母马与断奶后驹子通常会被饲喂富含可溶性碳水化合物的精补饲料，并搭配粗饲料。近期研究表明，精补饲料的使用与驹子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种母马（broodmare）的日粮是否会影响20至24月龄期间被过度饲喂的周岁马的代谢、骨关节状态与生长情况，以及青春期前公马驹的性成熟进程。本研究选取24匹鞍用母马，自妊娠中期至产驹阶段，分别饲喂仅粗饲料组（F组，n=12）与碎大麦+粗饲料组（B组，n=12）。公马驹于12月龄时进行去势。20至24月龄期间，所有周岁马均通过自动精补饲料饲喂器进行过度饲喂，饲喂量为其营养需求的140%。研究人员于6至24月龄期间对后代的生长情况进行监测；分别在19与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；并在24月龄时通过X光摄影检查探究骨关节状态。采用体视学技术与实时定量聚合酶链式反应（RT-qPCR）分析青春期前公马驹的睾丸结构与功能。断奶后各组的体重增长无显著差异。12月龄时，F组公马驹的睾丸成熟进程相较于B组出现延迟。自19月龄起，B组周岁马的管骨宽度显著大于F组。19月龄时，F组周岁马的胰岛素抵抗程度高于B组，但B组周岁马因营养过剩受到的影响更为严重，表现为胰岛素敏感性降低。24月龄时，各组的骨关节状态无显著差异。综上，妊娠种母马与生长中驹子的营养管理，可能会影响公马驹的性成熟进程，以及直至24月龄的驹子代谢状态。此类影响可能对成年马匹的繁殖与运动表现产生不利影响。