Abstract: 【Objective】 This experiment was conducted to investigate the effects of phospholipid (PL) and soybean isoflavone (ISO) supplementation on growth performance,meat quality and fatty acid composition in the breast muscle of Yellow-feathered broilers,in order to improve growth performance and meat quality of broilers through nutritional regulation,and to provide theoretical basis and technical support for improving quality and efficiency of Yellow-feathered broilers.【Method】 The experiment was 2 (with or without ISO in diet)×3(control,soybean phospholipid (SL) or lysophospholipid (LPL) in diet) factorial design.A total of 900 48-day-old female medium-growing Yellow-feathered broilers were randomly divided into 6 groups with 6 replicates per group and 25 broilers per replicate.The broilers in group 1 were fed basal diet supplemented with 3.00% rapeseed oil (control group).On the basis of control group,1.00% SL were used to replace rapeseed oil in the diet in group 2 (SL group).On the basis of group 1,500 mg/kg LPL products was supplemented in group 3,and in groups 4-6,300 mg/kg ISO products were supplemented on the basis of groups 1-3,respectively.The experiment lasted for 32 days.At 80 days of age,the broilers were weighed with fasting and feed intake was analysed to calculate the growth performance.One broiler with average body weight was selected for blood collection and slaughter,and the slaughter performance and plasma biochemical indexes were determined.The breast muscle was taken to evaluate the meat quality,malondialdehyde (MDA) content,volatile basic nitrogen (TVBN) content and fatty acid composition.【Result】 Compared to control group, supplementation of PL and ISO in the diets of female medium-growing Yellow-feathered broilers aged 48 to 80 days could significantly reduce the mortality of broilers (P＜0.05),and there was an interaction between them.Dietary PL or ISO supplementation significantly decreased the contents of GSSG and MDA in plasma (P＜0.05),significantly increased the ratio of GSH/GSSG in plasma (P＜0.05).Dietary LPL or ISO supplementation significantly decreased cooking loss of breast muscle(P＜0.05).Dietary PL supplementation significantly increased a^*_{45 min} and the contents of monounsaturated fatty acid(P＜0.05),and significantly decreased the content of n-6 polyunsaturated fatty acid (n-6 PUFA) in breast muscle (P＜0.05).Dietary SL supplementation significantly decreased MDA and TVBN contents in breast muscle (P＜0.05).Dietary ISO supplementation significantly increased plasma HDL-C and GSH content and the contents of PUFA,n-3 PUFA,linoleic acid and linolenic acid in breast muscle (P＜0.05),and significantly decreased plasma TG content and n-6 PUFA/n-3 PUFA values in breast muscle (P＜0.05).【Conclusion】 The supplementation of PL or ISO in the diet of female medium-growing Yellow-feathered broilers of 48 to 80 days of age could increase the antioxidant capacity,optimize the fatty acid composition in breast muscle,and improve the meat quality.

Key words: medium-growing Yellow-feathered broilers; phospholipids; soybean isoflavones; growth performance; meat quality; antioxidant capacity; fatty acid composition