Effects of dietary crude protein levels and Bacillus subtilis preparation on performance,egg quality,nutrient apparent metabolic rate,serum antioxidant and immune indices of Dagu breeding hens
This experiment was conducted to study the effects of the level protein and Bacillus subtilis preparation in diet on performance,egg quality,nutrient apparent metabolic rate and serum indices of Dagu breeding hens.A 3×2 two factors completely randomized experimental design was adopted with total of 576 38-week-old birds:PL0(crude protein 15.33%+Bacillus subtilis 0 mg/kg);PM0(crude protein 15.90%+Bacillus subtilis 0 mg/kg);PH0(crude protein 16.50%+Bacillus subtilis 0 mg/kg);PL1(crude protein 15.33%+Bacillus subtilis 200 mg/kg);PM1(crude protein 15.90%+Bacillus subtilis 200 mg/kg);PH1(crude protein 16.50%+Bacillus subtilis 200 mg/kg).The experiment lasted for 33 days.The results showed that:the laying rate of Dagu breeding hens fed the dietary protein levels with 15.90% and 16.50% were higher by 2.64% and 3.28% compared to those fed dietary protein levels with 15.33% (P<0.05),also average egg weight,average total egg weight,albumen height,apparent metabolic energy,the apparent metabolic rates of dry matter and crude protein was significantly improved(P<0.05).Furthermore,the feed to egg ratio significantly decreased by 6.27% and 7.12% (P＜0.05).The eggshell strength,eggshell thickness and Haugh units of the birds in the diet supplemented Bacillus subtilis preparation(BSP)groups improved 4.93%,5.41% and 3.00% (P＜0.05),respectively.And also the apparent metabolic energy,the apparent metabolic rate of dry matter,crude protein,calcium and phosphorus were significantly improved(P＜0.05).At the same time,the capacity of serum glutathione peroxidase activity,the level of serum calcium and serum phosphorus,the level of serum IgG and IgA of birds fed diet supplemented Bacillus subtilis preparation significantly improved(P<0.05);Simultaneously,the broken soft egg rate and the level of serum malondialdehyde significantly decreased by 1.16% and 14.42% (P<0.05).Dietary 16.50% protein level significantly increased serum capacity of glutathione peroxidase,but had no significant effect on other serum indexes(P>0.05).According to the comprehensive parameters,the dietary protein level of 15.90% was more suitable for the production requirement of the new strain of Dagu breeding hens in the late peak of egg production,and Bacillus subtilis preparation could improve the egg quality and metabolic rate of nutrients of Dagu breeding hens.
万方数据
维普
