Decreased levels of vitamin D₃ and supplementation with 1,25-dihydroxyvitamin D_3-glycoside on performance, carcass yield and bone quality in broilers

Diminuição dos níveis de vitamina D₃ e suplementação com 1,25-dihidroxivitamina D₃ glicosídeo sobre o desempenho, o rendimento da carcaça e a qualidade dos ossos em frangos de corte

ABSTRACT:

An experiment was performed to evaluate the effect of decreased levels of vitamin D₃ in the premix and 1,25-dyhydroxyvitamin D₃-glycoside (1,25(OH)₂D₃-glycoside) supplementation on performance, carcass yield and bone quality in 42d old broilers. Seven-d-old male chickens Cobb500^® were distributed in a randomized design with six treatments: a control diet with inclusion of vitamin D₃ in the premix, without supplementation of 1,25(OH)₂D₃-glycoside, and five diets with decreased levels of vitamin D₃ (100%, 75%, 50%, 25% and 0% about the control) plus the addition of 1,25(OH)₂D₃-glycoside, 50g ton^-1 of diet. The main results were to reduce the tenor of Vitamin D₃ in the premix when the addition of 1,25(OH)₂D₃-glycoside did not affect (P>0.05) the performance, carcass yield and bone quality variables. However, performance (feed intake, gain weight, feed conversion), yield (warm carcass weight) and bone quality (dry weight, length, mineral matter and breaking strength) of broilers fed with diets without vitamin D₃ in the premix and with addition of 1,25(OH)₂D₃-glycoside, which was the single source of vitamin D, had as a result very low (P<0.05) values comparing to the control. For the purposes of the present research, it was concluded that is possible the reduction of vitamin D₃ tenor in the premix up to 75% when the diet of male broilers is supplemented with 1,25(OH)₂D₃-glycoside. However, the use of 1,25(OH)₂D₃-glycoside as a single source of vitamin D, as tested here, is not recommended for broilers diets.

Key words:
bone growth; bone strength; calcitriol; poultry; Solanum glaucophylum.