不同叠层笼养密度对宁都黄鸡生长性能和血液指标的影响OA

To investigate the effects of different stocking densities under a layered cage-rearing system on the growth performance,body size development,and serum antioxidant capacity as well as stress-related blood parameters in Ningdu Yellow chickens,this study enrolled 58-day-old healthy,uniformly weighted Ningdu Yellow chickens and established four cage-density treatment groups:L8(8 birds/cage),L9(9 birds/cage),L10(10 birds/cage),and L11(11 birds/cage).All groups received identical environmental conditions,feed formulations,and management practices,with a trial duration of 58～120 days.Body weight,tibia length,and tibia circumference were measured every 7 days,while blood samples were collected at the end of the trial to measure total antioxidant capacity(T-AOC),superoxide dismutase(SOD),malondialdehyde(MDA),glutathione peroxidase(GSH-PX),corticosterone(CORT),and creatine kinase(CK).Results showed that only during the 99-106-day age range did group L9 exhibit significantly higher average daily weight gain than groups L8 and L11(P＜0.05);no significant differences were observed in total daily weight gain across all age groups.No significant intergroup differences were found in tibia length or circumference at any age(P＞0.05).At 120 days of age,groups L9 and L10 demonstrated significantly greater body oblique length than group L11(P＜0.05),while group L9 exhibited significantly longer keel length than group L11(P＜0.05).High-density group L11 showed significantly higher serum T-AOC and SOD activity compared to low-density group L8(P＜0.05),whereas no significant intergroup differences were observed for MDA,GSH-PX,corticosterone,or CK levels.The results demonstrated that a density of 9 birds per cage was optimal for layered cage housing under these experimental conditions;the range of 8-11 birds per cage did not significantly inhibit skeletal development in Ningdu Yellow chickens,while high density merely induced antioxidant compensatory responses without causing significant chronic stress-related damage.