TURKISH JOURNAL OF VETERINARY & ANIMAL SCIENCES, cilt.33, sa.6, ss.469-476, 2009 (SCI-Expanded)
This study was conducted to determine the effects of 2 lighting programs (continuous: 24 h light: 0 h dark; intermittent: 12 h daylight followed by 3 cycles of 1 h light, and then 3 h dark during the night) and 3 ascorbic acid supplementations (0, 200, and 400 mg/L added to water) on broiler performance, bone characteristics, and the incidence of tibial dyschondroplasia. One-day-old male commercial (Ross PM(3)) broiler chicks (600) were divided into 6 treatment groups (2 x 3) with random replicates (4 replicates per treatment). At the end of 6 weeks data revealed that the lighting program, which was one of the main factors tested, affected the feed conversion ratio and live weight gain (P < 0.05), while ascorbic acid (the other main factor) and the interactions of both factors did not significantly influence broiler performance characteristics. Length and weight of the tibiotarsus were positively affected by the use of intermittent lighting, whereas ascorbic acid had a positive effect only on the weight of the bone. Continuous lighting improved cortical thickness of the tibiotarsus (P < 0.01) and decreased the incidence of tibial dyschondroplasia insignificantly. There was not a lighting x supplemental ascorbic acid interaction for tibial dyschondroplasia.