Hormonal and metabolic adaptations in Omega-3-supplemented rabbit does during their first reproductive cycle

This study evaluated the effects of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) supplementation on endocrine and metabolic profiles of forty-five nulliparous rabbit does during their first reproductive cycle. Animals were randomly assigned to one of three diets: control (CNT), 5% extruded linseed (L), and 5% extruded linseed plus 0.2% Padina pavonica extract (LPP). Blood was sampled at baseline, artificial insemination, parturition, mid-lactation, and weaning, to determine the concentrations of cortisol, insulin, leptin, thyroid hormones (T3, T4), glucose, and non-esterified fatty acids (NEFA). Reproductive stage significantly influenced endocrine and metabolic dynamics, with cortisol and NEFA peaking at parturition (p < 0.001). Supplemented groups, particularly LPP, showed higher T3 concentrations (p < 0.05) and T3/T4 ratios (p < 0.01). The L diet maintained higher insulin during lactation (p < 0.05), while LPP lowered leptin at parturition (p < 0.01) and NEFA at insemination (p < 0.01), indicating an early decrease in lipid mobilization. Multivariate analysis suggested that n-3 PUFA supplementation promoted an endocrine profile characterized by enhanced thyroid activity and reduced lipid mobilization, consistent with a potentially favorable metabolic shift. In conclusion, enriching diets with n-3 PUFA, especially linseed combined with Padina pavonica extract, represents a promising nutritional strategy to support rabbit does during the highly demanding phases of their first reproductive cycle.