The effects of obesity and insulin dysregulation on mare reproduction, pregnancy, and foal health: a review

Abstract

Obesity is a growing welfare concern in modern equine populations and predisposes horses to disturbances in energy metabolism such as insulin dysregulation. However, equine metabolic syndrome has only been recognized in recent decades. Functioning energy metabolism is pivotal to normal body homeostasis and affects essentially all organ systems, including reproduction. Previous literature suggests that obesity has an effect not only on the reproductive processes in mares but also on offspring health, predisposing the offspring to later-onset orthopedic and metabolic problems. This review focuses on the effects of obesity, insulin dysregulation and hyperinsulinemia on the reproductive functions of mares and the implications on foal health before and after birth. The points of interest are the cyclicity and ovarian function, uterine environment, gestation, the postpartum period, and the newborn foal. The aim is to review the current state of knowledge, and identify outstanding questions that could stimulate future research. This topic is important not only from the equine industry and production perspective but is also relevant for the welfare of future populations and individuals.

Monthly and Pregnancy-Related Concentration of Cu and Zn in Serum of Mares in an Equine Breeding Herd

“…These changes during pregnancy are significant because stressors can affect the foal's size, cardiovascular and pituitary-adrenal function, carbohydrate levels, etc. [6,7]. The nutrition of the mare during pregnancy can also have a significant impact on the health of the foal [8].…”

“…Proper conceptus nutrition Agriculture 2024, 14, 35 2 of 15 during the pregnancy affects the first months of life as well, allowing for the storage of more necessary compounds [8]. As metabolism and nutrition are crucial for fetal development, it is important to understand the role of minerals in the health of pregnant mares and their offspring, including Cu and Zn [1,[6][7][8][9][10][11].…”