RESUMO
Teressa goat is a unique goat breed in Andaman and Nicobar Islands (ANI) of India. Effects of Flaxseed oil (FSO) supplementation in body weight (BW), scrotal circumference (SC), testicular volume (TV) and testicular weight (TW), endocrinological profiles, sex behavioural profiles (SBPs), oxidative stress markers and semen production and its quality profiles in rainy and dry summer season were studied in Teressa goat. Male goats (n = 12) of 3-4 years old were equally divided into control and treated groups. Treated animals received 25 mL FSO per day. Oral drenching of FSO was done in the morning before feeding the concentrate ration. Body weight, scrotal circumference, TV and TW were measured in bucks of FSO treated and untreated during rainy and dry summer seasons. Blood follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), cortisol and prolactin, total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and malondialdehyde (MDA) were measured in bucks of FSO treated and untreated during rainy and dry summer seasons. Libido score (LS), mating ability score (MAS) and sex behavioural score (SBS) were estimated at time of semen collection in bucks of FSO treated and untreated during rainy and dry summer seasons. Semen samples (n = 100; 50 semen samples from each season; each 25 semen samples from control and treatment groups per season) were collected and analysed for semen quality profiles. One-way ANOVA (control rainy, control dry, treated rainy and treated dry) revealed that BW, SC, TV and TW, FSH, LH, testosterone, TSH, T3 and T4 were higher (P < 0.05) and cortisol and prolactin were lower (P < 0.05) in FSO treated bucks of rainy season followed by untreated bucks of rainy season, FSO treated bucks of dry summer season and were lower (P < 0.05) in untreated bucks of dry summer season. Similarly, TAC, CAT, SOD and GSH, LS, MAS and SBS, and volume, pH, sperm concentration, mass activity, total motility (TM), viability, acrosomal integrity (AcI), plasma membrane integrity (PMI) and nuclear integrity (NI) were higher (P < 0.05) and MDA and TSA were lower (P < 0.05) in FSO treated bucks of rainy season followed by FSO treated bucks of dry summer season, untreated bucks of rainy season and were lower (P < 0.05) in untreated bucks of dry summer season. The results of the present study indicated that the breeding bucks suffered physiological stress (higher cortisol), oxidative stress (higher MDA and deficiency of antioxidants), hormonal imbalance (higher prolactin and cortisol and deficiency of gonadotropins, gonadal hormone and thyroid hormones) and infertility due to poor libido and poor semen production and its quality profiles during dry summer season. Thus, dry summer was more stressful season compared to rainy season for the goat bucks. FSO supplementation mitigated these stresses and improved the scrotal and testicular biometrics, libido, antioxidants, hormones and semen quality profiles in Teressa goat bucks. The current study concluded that FSO effectively improved the hormones, libido, antioxidant profiles, and scrotal and testicular biometrics with cascading beneficial effects on semen quality profiles in Teressa goat bucks under humid tropical island ecosystem of Andaman and Nicobar Islands.