Effects of different intermittent illumination patterns on production performance of slow growing type Yellow chickens

Abstract

Abstract The objective of this study was to investigate the effects of intermittent illumination around noontime on the F line of slow growing line of Yellow chickens. The chickens were randomly divided into three groups of 70 roosters and 100 hens kept under three different illumination patterns. Group I was the control group (16 h of illumination at 10 lux). After day 21, in group II the light was additionally turned off during noon from 12:00–13:00 and in group III from 12:00–14:00 based on the lighting schedule of group I. The results showed that there was no significant difference in body weight (BW) between the three groups during the first 21 days ( p> 0.05). On day 42, BW of roosters and hens in group II was 35.2 g/21.7 g and 39.7 g/27.3 g higher than that of those in groups I and III ( p< 0.05), but there were no significant differences between group I and III ( p> 0.05). Oblique body length and shank length of group II were significantly higher than in groups I and III (p<0.05). After day 43, feed conversion ratio of group II was significantly higher than in groups I and III (p < 0.05). Comb perimeter, area and vertical area of group I were significantly higher than in groups II and III, and in group II these parameters were significantly higher than in group III (p<0.05). Slaughtering weight and breast muscle percentage of group II were significantly higher than in groups I and III, leg muscle percentage was significantly lower in group III ( p< 0.05) compared with the other groups. On day 84, there were no significant differences in blood indices (IGF-1, growth hormone, testosterone) or meat quality indices (flesh colour, shear force, PH, and water-holding capacity) between the three groups ( p> 0.05), but some indicators in group II showed an increasing trend. Based on these results, the intermittent light pattern of group II not only saved electrical energy and diet resources but also improved some indices of production performance.