Effects of Methionine Configuration and Supplemental Level on Growth Performance,Carcass Quality,Meat Quality and Plasma Methionine Metabolism Related Enzyme Activity of Yellow-Feathered Broilers
This experiment was conducted to investigate the effects of dietary methionine(Met)supplementa-tion with different configurations and levels on growth performance,carcass quality,meat quality and plasma Met metabolism related enzyme activity of medium-speed yellow-feathered broilers,in order to determine the Met requirement and the relative biological titer of L-Met to DL-Met in medium-speed yellow-feathered broil-ers.The experiment was divided into 2 independent feeding experiments with each 1 584 healthy and well-de-veloped female Kelang spotted-brown chickens at 31 and 61 days of age were selected and randomly divided in-to 11 groups with 6 replicates per group and 24 chickens per replicate,respectively.The chickens in each group were fed a basal diet supplemented with 0(control group,shared by two configurations),0.04％,0.08％,0.12％,0.16％and 0.20％L-Met or DL-Met,respectively.The experiment lasted for 50 days.The results showed as follows:1)compared with the control group,dietary Met supplementation significantly increased the average daily gain and average daily feed intake of yellow-feathered broilers from 31 to 60 days of age(P＜0.05),significantly decreased the ratio of feed to gain(P＜0.05),and the effects of L-Met was better than that of DL-Met(P＜0.05);dietary Met supplementation had no significant effect on growth performance from 61 to 80 days of age(P＞0.05).2)Compared with the control group,dietary L-Met supplementation signifi-cantly increased the breast muscle rate of yellow-feathered broilers at 60 days of age(P＜0.05),and dietary DL-Met supplementation had a trend of increasing the breast muscle rate at 60 days of age(P=0.06);dietary Met supplementation had no significant effect on carcass quality at 80 days of age(P＞0.05).3)Compared with the control group,dietary DL-Met and L-Met supplementation significantly decreased the breast muscle shear force of yellow-feathered broilers at 80 days of age(P≤0.05).4)Compared with the control group,di-etary DL-Met and L-Met supplementation significantly decreased the betaine-homocysteine methyltransferase(BHMT)activity in plasma of yellow-feathered broilers at 80 days of age(P＜0.05).Compared with DL-Met,dietary L-Met supplementation significantly increased the BHMT activity in plasma of yellow-feathered broilers at 60 days of age(P＜0.05),and significantly decreased the methionine adenosyltransferase activity in plasma(P＜0.05);dietary L-Met supplementation significantly increased the cystathionine-β-synthase activity in plasma at 80 days of age(P＜0.05).In conclusion,under the conditions of this experiment,using average daily gain as the evaluation index and according to quadratic regression analysis,the optimal dietary DL-Met and L-Met supplemental levels for medium-speed yellow-feathered broilers from 31 to 60 days of age are 0.16％and 0.20％,and the corresponding dietary Met requirements are 0.42％and 0.46％,respectively;the dietary Met requirement is not higher than 0.23％from 61 to 80 days of age.Using average daily gain as the e-valuation index,the relative biological titer of L-Met to DL-Met in medium-speed yellow-feathered broilers from 31 to 60 days of age is 154.1％according to nonlinear curve fitting.[Chinese Journal of Animal Nutri-tion,2024,36(12):7710-7724]
万方数据
维普
