The effects of maternal supplementation of selenium and iodine via slow-release blouses in late pregnancy on milk production of goats and performance of their kids

Forty pregnant dairy goats were used in a 2 × 2 factorial arrangement of treatments to evaluate the effects of prepartum supplementation of selenium (Se) and iodine (I) as slow-release boluses. The boluses were administered four weeks prior to the expected kidding time to supply daily amounts of (1) 0 mg Se and 0 mg I, (2) 0 mg Se and 0.40 mg I, (3) 0.25 mg Se and 0 mg I and (4) 0.25 mg Se and 0.4 mg I. Milk production, milk fat percentage, daily production of milk components, milk selenium and iodine concentrations were greater in goats received 0.25 mg Se/day than no supplemental Se (p < .05). Milk production, daily production of milk compounds, milk iodine concentration, serum T3 and T4 concentrations in goats received 0.40 mg I/day were greater than goats received no supplemental I (p < .05). Bodyweight at weaning and average daily gain in kids whose mothers were received 0.25 mg Se/day were greater than zero Se (p < .05). Bodyweight at weaning and average daily gain in kids whose mothers were given 0.40 mg I/day were greater than zero I (p < .05). Serum Se and T3 concentration and whole blood glutathione peroxidase activity were significantly greater in goats and their kids received 0.25 mg Se/day than goats received no supplemental Se (p < .05). There was no Se level × I level interaction for all assessed parameters. Results showed that maternal supplementation of Se and I as a slow-release ruminal bolus in late pregnancy improved milk production of grazing goats and the performance of their kids.Highlights Intra-ruminal administration of slow-release boluses containing selenium and iodine improved milk production of grazing goats. Kids from goats receiving supplemental selenium and iodine via intra-ruminal boluses perform better. Intra-ruminal administration of slow-release boluses containing selenium in late pregnancy improved the antioxidant status of grazing goats and their kids.