On top dose of vitamin D as the only source in the first week of broilers

Abstract

The objective of this study was to evaluate the performance of broiler chicks in the first week of age. The study was performed with the inclusion of two vitamin D metabolites as the only source of vitamin D in the broiler’s diet. For this purpose, 308 768-day-old male Ross chicks were used, hosted in 96 pens of 0.36 m2 each. The experiment consisted of six treatments distributed in a completely randomized block design, in a factorial model of 2 x 3. Two vitamin D metabolites 25-hydroxy cholecalciferol and 1,25- dihydroxycholecalciferol and three levels of inclusion of each metabolite (34.5, 69.0 and 93.5 μg/kg) and (0.5, 1.0 and 1.5 μg/kg), respectively. The experiment was performed with 16 replications per treatment and eight animals per experimental unit. The main parameters of study were: final body weight (BW), average daily feed intake (ADFI), average daily gain (ADG), feed conversion ratio (FCR) and mortality (M). The birds fed with 25-hydroxy cholecalciferol presented a better ADG (p = 0.03) and ADFI (p = 0.00) in contrast to the 1,25- dihydroxycholecalciferol, FC (p = 0.16) and M (p = 0.37) were not affected by the vitamin D metabolite. The use of 34.5 μg/kg of metabolite 25-hydroxy cholecalciferol fed during the first week of life to the broilers show better zootechnical results with respect to 1,25-dihydroxycholecalciferol. This study led to the conclusion that 1,25-dihydroxycholecalciferol is not recommended as the only source of vitamin D when it comes from an herbal source.