Effect On Meat Quality Of Grazing And Confinedness Of Wulate Goat

In this experiment,12-month-old Wular goats(there were 6 grazing and feeding goats respectively)were used to determine the eating quality(pH,color,tenderness,cooking loss)and nutritional quality(protein,moistu re,fat,ash,fatty acid,amino acid,flavor substances).In order to analyze the effects of two feeding methods on meat quality,during the post-mortem maturity process,the changes of meat quality were compared to determine the acid ripening time under the best quality of mutton.This study provides a reference for improving the quality of mutton.The results showed that the pH24 of the biceps femoris in the grazing group was significantly higher than that in the feeding group(p<0.05).The shearing force and a*value of the biceps femoris in the grazing group was significantly lower than that in the feeding group(p<0.05).The cooking loss rate of the longissimus dorsi muscle in the grazing group was significantly lower than that in the feeding group.The intramuscular fat content in the feeding group was significantly higher than that in the grazing group(/?<0.05).The water content conjugated linoleic acid and a-linolenic acid of the biceps femoris in the grazing group was significant-ly higher than that in the feeding group(p<0.05).The contents of SFA,MU-FA,PUFA and n-3 PUFA in the longissimus dorsi of the grazing group were significantly higher than those in the feeding group(p<0.05).The content of hexanal and furfural in the longissimus dorsi in the grazing group was significantly higher than that in the feeding group(p<0.05).The content of benzyl alcohol,octanol and sterol in the biceps femoris was significantly higher in the grazing group than in the feeding group(p<0.05),the content of biceps capricin was significantly lower(p<0.05).T-he value of E/T in the biceps femoris in the grazing group was closer to 0.4 than the feeding group,which is the national standard proposed by FAO/WHO.The value of TEAA/TNEAA in the longissimus dorsi of the grazing group was closer to 0.6 proposed by the national FAO/WHO than the feeding group.Compared with house feeding,it showed that grazing raising can improve the succulent ness,tenderness,fat content,flavor and nutritional value of mutton.With the increase of acid removal time after slaughter,the pH value of mutton showed a linear change trend.Within 48 hours after slaughter,the pH decreased significantly(p<0.05),and began to rise after reaching the limited value of pH.At the same time,slow acid discharge significantly improved the tenderness of the mutton(p<0.05).The minimum cooking loss rate(p<0.05)was reached on the 2-3rd day of acid removal.In the 4 days after acid release,the changes of saturated fatty acids,unsaturated fatty acids,aldehydes,alcohols,ketones and EAA,NEAA,TAA,E/T and EAA/NE AA increased first,then decreased and finally stabilized.The content and ratio of fatty acid,flavor substance and amino acid were higher than that before the acid discharge on the first 1-3 days of acid removal.In general.the third day of acid removal was the best acid ripening time of the mutton.The pH value of grazing captivity reached the limit pH on the second day of acid removal.The shear force value of the biceps femoris muscle reached a significant maximum of 74.70N(p<0.05)on the first day of acid-discharging in grazing group,while the feeding group reached the maximum on the second day of acid-discharging.The process of acid excretion has 4 days,the cooking loss rate of the longissimus dorsi muscle in the grazing group reached a minimum of 33.86%(p<0.05)on the third day,and the feeding group reached a minimum of 36.20%on the second day of acid removal(p<0.05).In the grazing group,the a*value of the biceps femoral muscle reached the maximum value of 35.96(p<0.05)on the 2nd day of acid-discharging,and the feeding group reached 16.69 on the first day.The content of conjugated linoleic acid and n-6 PUFA in the longissimus dorsi of the grazing group reached a significant maximum of 1.70%and 4.82%(p<0.05)on the second day of acid removal,while The feeding group reached a significant maximum of 2.88%and 4.72%(p<0.05)on the third day(p<0.05).The content of nonanal and 1-Heptanol in the biceps femoris in the grazing group reached a significant maximum of 25.43(106 AU/g)(p<0.05)on the first day and 3.77(106 AU/g)on the third day of acid removal,respectively(D<0.05),the feeding group reached a significant maximum of 31.35(106 AU/g)and 6.71(106 AU/g)(y<0.05)on the first day.It can be concluded from the above that the grazing group has a longer maturity than the house feeding group,and the time of improving meat quality is more adequate,the degree of perfection is more comprehen-sive,and the effect of meat quality is better.