NEFA, BHBa and gamma-GT variation in the blood serum of weaned foals up to 18 months of age

The correct energy balance estimation of the growing foal may represent an issue for the nutritionist, given the dynamic change in body composition and fat tissue depots. In fact, the maintenance of adequate body weight and body measures over time for optimal growth curve accomplishment and the fulfilment of nutrient requirements are fundamental to address adequate individual feeding plans of the future sport horse. The metabolic profile of selected metabolites could be helpful in interpreting growth homeostasis and some of these could be used as indicators of energy balance state and liver health. Against this background, the literature on circulating indicators of homeostasis perturbation during the growth of foals is poor. We hypothesised that metabolites indicating the energy balance like non-esterified fatty acids (NEFA), β-hydroxy-butyric acid (BHBa) and liver enzyme like γ-glutamyl-transferase (γ-GT) [interpreted in the light of circulating total bilirubin (TBIL) and aspartate aminotransferase (AST)] may be used to monitor the growing foals from weaning to 18 months of age. For this purpose, a total of 12 Anglo-Arab (AA) foals from the same stable were enrolled in this trial. All foals were serially weighed on a digital scale and sampled for total blood at weaning, at 12- and 18-months of age. Feeding and rearing conditions were adopted simultaneously equal for all the foals used. All data were processed by a repeated measure ANOVA.