Effects Of Light Intensities And Dietary Nutrition Levels On Beijing You Chicken’ Production Performance,Meat Quality, And Welfare

This trial was conducted to investigate the effects of light intensity and major nutritional factors on production performance, carcass quality, sexy maturity, meat quality and the welfare of Chinese commercial broilers. A3×4factorial arrangement of three diets and four lighting intensities was used. Hatchling Chinese color-feathered broilers (N=1728) were allocated to four rooms, each containing12pens of36birds (male:female=1:1). All rooms were illuminated using20lx from d1to d7; thereafter, light intensity was1,10,30or50lx. The three rations had the same ratio of CP/ME at the same growth stage, but different nutrient densities were provided, high level (H), middle level (M), low level (L), ad libitum. Average feed intake (AFI), average body weight gain (ABWG), AFI/ABWG (F/B) of1-5w (First stage),6-9w (Middle stage),10-13w (Last stage),1-13w (Whole life) were separately determined. At d90,6birds (3males and3females) were randomly chosen from each pens, and slaughtered to measure the carcass traits, sexual maturity performance, and so on. The results are as follows:1、There was significant interaction effect on the carcass percentage between light intensity and nutrient levels (P=0.02). The treatment of10lx and high nutrition level can improve the carcass percentage extremely (P<0.01).There were significant interaction effect between light intensity and nutrient levels on the comb weight and thickness of the hens, and the testis weight and comb thickness of the cock. The treatment of101x and H increased the weight of comb significantly (P<0.05), the treatments of30lx and M improved the weight of the testis significantly (P<0.05), the treatments of301x and L,301x and M could improve the thickness of the comb (P<0.05).2、In the first stage, the light intensity of11x,101x had an extremely advantage on the AFI and ABWG, with the decreasing of feed consumption(P<0.01). In the middle stage, the AFI of 11x was extremely higher than that of30lx and50lx (P<0.01). There were no significant differences for ABWG (P>0.05). As for the whole life, the AFI of1lx was extremely higher than the30lx and50lx (P<0.01). For ABWG and F/B, no significant differences were found (P>0.05).The L level can decrease AFI and ABWG extremely and increase F/B in the first stage (P <0.01). For the whole stage, the M level could improve ABWG, decrease F/B (P<0.01), the H level had no significant advantages on the AFI and ABWG3、Light intensity had no significantly effect on the carcass traits of Chinese yellow-feathered broilers (P>0.05). The carcass traits of H was extremely higher than others (P <0.01). The eviscerated percentage of H was significantly higher (P<0.05). M could improve thigh meat percentage significantly (P<0.05),4、The comb thickness of the hens and the cock comb (weight, height, thickness) in301x were significantly higher than others (P<0.05). The secretion of growth hormone and melatonin in501x were extremely lower than others (P<0.01). The H improved the growth of the hen comb significantly (P<0.05), had an tendency to increase the weight of the ovary (P=0.08).4、Light intensity had an significant effect on the pH of24h after slaughtering, the pH of501x was significantly higher than that of11x and101x (P<0.05).5、Neither of these two factors had significant effect on the development of the eye(P>0.05). Both the side-to-side and back-to-front diameter of11x group were bigger than that of other groups. Light intensity had significant effect on the development of the legs, the gait score of10lx was significantly lower than other groups(P<0.05). The nutrition levels had no significant effect on the gait sore(P>0.05).For the broilers behavior, it turned out broilers in11x had more time to stay calm (standing, sleeping), less time to be active. However, the broilers in501x were on the contrary.Take the production performance, carcass traits, sexual maturity, meat quality and welfare into consideration, we can conclude that the light intensity of5-301x was effective enough for the broilers. High light intensity and the nutrition could promote the sexual maturity.