Maternal Nutrition during Pregnancy Affects Testicular and Bone Development, Glucose Metabolism and Response to Overnutrition in Weaned Horses Up to Two Years

Abstract

IntroductionPregnant 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.Material and methodsTwenty-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.ResultsPost-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.ConclusionIn 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.

Maternal obesity increases insulin resistance, low-grade inflammation and osteochondrosis lesions in foals and yearlings until 18 months of age

“…Plasma insulin concentrations were measured using an AlphaLISA human insulin immunoassay kit (PerkinElmer, USA) as previously described and validated [ 51 ]. The minimum level of detection was 5.3 mUI/L.…”

“…Glucose effectiveness (Sg), acute insulin response to glucose (AIRg), insulin sensitivity (SI) and the disposition index (DI) were calculated using the Bergman’s minimal model [ 50 , 52 , 53 ] on the MinMod Millennium software (Ver 6.02, MINMOD Inc., 2001) [ 54 ]. A schematic representation of the Bergman’s minimal model has been described previously [ 51 ]. The goodness of fit r 2 of models for all mares was 91.5% (range 74.6–98.22) and all the parameters were estimated with a fractional standard deviation (FSD) <0.5.…”

ECEIM consensus statement on equine metabolic syndrome

“…More recently, genome wide association studies have been undertaken using Arabian horses, Welsh ponies, and Morgan horses, and several candidate genes were identified associated with relevant traits including height and insulin, triglyceride, and adiponectin concentrations . Nutritional status and body condition of the mare during pregnancy influences the foal in terms of reproductive, orthopedic, and metabolic responses later in life, probably related to epigenetic changes in utero …”

Testicular development in male lambs prenatally exposed to a high‐starch diet

“…The concept that the nutritional management of the pregnant dam may affect the development and function of the male offspring is supported by growing evidence in rodents (Genovese, Núñez, Pombo, & Bielli, ), sheep (Alejandro et al, ), horse (Robles et al, ), and cattle (Weller et al, ). However, these studies investigated the impact of nutritional restriction or excess.…”