| Xueshan chicken, provided by Lihua Poutry Company, Jiangsu Province, was used to evaluate the effects of grazing patterns on slaughter performance, meat quality and flavors of tested birds. The results of the trial were aimed to provide useful information in establishing an efficient and high quality poultry farming.Exp.1:Three thousands intensive raised Xueshan chicken(80d rooster and120d hens, equal gender ratio) were randomly divided into2groups. Free graze was adopted to the test group during the day and compound feed was given once in every night, and intensive feeding pattern remained to the control group in later stage. There were5replicates in each group. For test group, there were500chicken in each replicate and100chicken for control group. The trial lasted for2months. After30d and60d,4cocks and4hens in each replicate were randomly selected, the live body weight, slaughter performance and other parmeters were meansured. The results showed that (1) the live body weight of grazing group was lower than the control group;(2) the abdominal fat of grazing group was7.64%and40.61%lower than that of control group, respectively. The ratio of cock’s abdominal fat was significantly lower than that of hens (P<0.01).(3) The ratio of chest muscle of grazing birds was lower than that of control while the leg muscle was opposite to that of chest muscle, but the difference was not significant. The ratio of cock’s chest muscle was significantly lower than that of hens (P<0.01), and leg muscle was8.02%and10.16%higher than that of hens, respectively.30d and60d in test,(1) the brightness (L*) of chest muscle of grazing group was higher than the control one (P<0.05), while the yellowness was on the opposite. The redness(a*)was14.81%and24.22%higher respesitively than the control group,which was significant only in30d for grazing (P<0.05).(2) The value of leg muscle L*and a*were higher than that of the control, the difference were significantly while in60d’ trail (P<0.05). The value of leg’s L*and a*increased while the yellowness decreased, but the difference was not significant.Exp.2:The chest, leg muscles were collected in this trail, then analyzed the protein, fat, water and other indicators. The results showed that (1) the breast and leg muscle protein of grazing group was2.02%and3.83%higher respectively than the control one after30d in test, while3.84%and3.17%higher in60d. The protein of breast was higher than the leg during the test period.(2) The ratio of chest and leg fat declined during the trail which were showed that grazing pattern had much more impact on nutrition.(3) The leg moisture was significantly higher than the control group after60d (P<0.01).The influence of sex on nutrients appeared significant of Xueshan chicken. Cock’s muscle moisture was11.18%higher than hen’s (P<0.05), while the ratio of hen’s breast muscle fat was significangtly higher than cock (P<0.01).The leg fat of cock was23.75%lower than the hen’s in60d which the difference was significantly (P<0.01).Exp.3:The inosinic acid, free amino acids, fatty acids and LPL activity in breast and leg muscle were compared in this trail. The results showed that the level of Met and Tyr of chest were24.72%and35.71%higher respectively than control one in30d while the total free amino acids and essential amino acids were higher than the control group (P<0.05),which was opposite to that of leg muscle. In30d, the Gly of leg muscles was48.03%lower than the control birds.After30d, linoleic acid of grazing group of breast and leg muscle was higher than the control group, the difference was significantly (P<0.05). The ratio of monounsaturated fatty acids and essencial fatty acids were significantly higher than the conrtol group (P<0.01), while the palmitic oil acid and palmitic acid on the contray, the difference was significantly (P<0.05).After60d, the LPL activity of hen’s leg muscle was higher than cock (P<0.01). The content of inosinic acid of leg was8.5%higher than the control birds in30d. |
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