BONE CHARACTERISTICS OF BROILERS SUPPLEMENTED WITH VITAMIN D

Abstract

Vitamin D is added to broiler diets to supply its physiological requirement for bone formation. The fast growth rate of modern broilers is often associated with poor bone formation. Increasing vitamin D supplementation levels and the use of more available sources have applied to try to prevent leg problems, to increase carcass yield, and to improve the performance of broilers. The present study evaluated three vitamin D supplementation levels (1) 3,500 IU (control); (2) control + 1,954 IU of 25-hydroxycholecalciferol; and (3) control + 3,500 IU of vitamin D in broiler diets supplied up to 21 days of age. The objective was to investigate if the vitamin D levels above the recommendations could reduce leg problems in broilers. In this experiment, a total of 1,296 one-day-old male and female Cobb(r) 500 broilers were used. A 2 x 3 factorial arrangement was applied, consisting of two sexes and three vitamin D levels. No difference was found between the levels of vitamin D (p > 0.05), the performance of males or females, the gait score, the valgus and varus incidence, the tibial dyschondroplasia incidence, the occurance of femoral degeneration, the bone colorimetric, and the carcass yield. Parts yield differences were found (p > 0.05), except for liver and intestine yields. We concluded that the lowest tested vitamin D level (3,500 IU per kilogram of feed) added to the diet was the best choice in terms of cost/benefit to help minimizing leg problems in broilers.