Season modulates endocrinological profiles and sex behavioural characteristics in indigenous male goats under tropical humid island ecosystem

Abstract

Objective: To measure the seasonal effect on endocrinological profiles and sex behavioural profiles during rainy and dry summer seasons in male Andaman local goat in Andaman and Nicobar Islands, India. Methods: Ten adult male Andaman local goats were selected from the goat breeding farm, ICAR-Central Island Agricultural Research Institute, Port Blair, Andaman and Nicobar Islands, India. Endocrinological profiles such as follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), cortisol and prolactin were analysed with enzyme-linked immunosorbent assay kits. Sex behavioural profiles such as libido score, mating ability score and sex behavioural score were measured during rainy and dry summer seasons in male Andaman local goat. Results: Endocrinological profiles as well as sex behavioural profiles differed significantly between rainy season and dry summer season (P<0.05). The levels of FSH, LH, testosterone, TSH, T3, and T4 were significantly higher in rainy season than in dry summer season whereas cortisol and prolactin were significantly higher in dry summer season than in rainy season (P<0.05). The ratio of T3:T4 was significantly higher in rainy season than in dry summer season. Similarly, libido score, mating ability score and sex behavioural score were significantly higher in rainy season than in dry summer season (P<0.05). Conclusions: Rainy season has significantly higher beneficial effects than summer season on reproduction and artificial breeding programmes in semi-intensive management of goat under the tropical humid island ecosystem in Andaman and Nicobar Islands.

Keywords

• andaman and nicobar islands; hormone; goat; libido; season; tropical humid island; island ecosystem; rain fall; temperature humidity index; light hour