Endocrine, Nutritional and Photothermal Modulation of Gestation Length in Crossbred Goats (Capra hircus): A Controlled Trial of Hormonal Induction, Metabolic Markers and Environmental Management to Optimize Parturition Timing and Kid Viability

Abstract

This study evaluated the feasibility of shortening gestation length in crossbred Anglo-Nubian × native goats (Capra hircus) through endocrine induction, while monitoring maternal metabolic status, natural photothermal conditions, and neonatal viability under tropical conditions. Twenty pregnant does were randomly assigned to a control group (natural parturition) and an induced group receiving prostaglandin F₂α (15 mg) and dexamethasone (10 mg) on day 144 of gestation. Gestation length, parturition timing, maternal endocrine and metabolic biomarkers (progesterone, cortisol, IGF-1, leptin, glucose, β-hydroxybutyrate), ambient temperature and light conditions, and neonatal outcomes were assessed. Hormonal induction significantly reduced gestation length by approximately four days (p < 0.01) and synchronized parturition without increasing maternal stress or metabolic imbalance. Progesterone declined rapidly following induction, mimicking natural luteolysis, while cortisol responses were comparable between groups. Metabolic biomarkers remained within physiological ranges, indicating adequate nutritional support. Birth weights, neonatal vigor, and survival to weaning did not differ between induced and control kids. The findings demonstrate that controlled endocrine induction near term can safely modulate gestation length in crossbred goats without compromising neonatal viability, offering a practical reproductive management strategy for tropical smallholder and institutional goat production systems.