Productive, thermoregulatory, and hormonal responses of dairy goats supplemented with selenium-enriched yeast in the Brazilian semi-arid region

AbstractThe aim of this study was to evaluate the effect of adding selenium-enriched yeast (SE) in the diet of dairy goats during 60 days of lactation and its effect on productive, thermoregulatory, and hormonal responses of animals managed in a semi-arid region. Sixteen Saanen × Toggenburg crossbred goats were used in a completely randomized design. Goats were weighed, and their milk yield was monitored weekly. Before the animals entered the treatments and at every 20-day milk producing, blood samples were collected to determine theSE levels. At 20, 40, and days of the lactation cycle, individual milk samples were collected to determine composition, casein, urea nitrogen, and selenium content. Measurements of respiratory rate (RR), rectal temperature (RT), coat surface temperature (CST), and epidermal temperature (ET) were performed weekly during the experimental period in two shifts, one in the morning (9 am) and the other in the afternoon (3 pm). No difference (P> 0.05) was detected for body weight, milk yield, composition, selenium concentration, and urea nitrogen. Lower RR and ET (P< 0.05) were observed for animals that receivedSE supplementation. Thyroid hormone concentrations were similar between treatments (P> 0.05). The positive results of theSE supplementation were concentrated in thermoregulatory responses, and there was no effect on productive, hormonal responses, and plasmatic concentration of selenium in the milk. TheSE supplementation for dairy goats ...
Source: Tropical Animal Health and Production - Category: Veterinary Research Source Type: research