The Comparative Study On Growth And Meet Performance Of Different Fattening Phase In Xinjiang Brown Cattle

27 Xinjiang brown bulls aged at 1-6 months were employed in this study, which were divided into three groups(A.B.C) according to the fattening period.First,27 Xinjiang brown bulls were fattened,of which 12 finished bulls were slaughtered,the performance of growth and beef yield as well as meat quality were tested. The results were as follows: 1 The longer the fattening period was,the larger body weight and body size of Xinjiang brown bulls were attained during 16-22 months of fattening period.The order of body high at hinter quarter, body height in the front, chest circumference, circumference of cannon bone and weigh of experimental bulls of three groups were A<B<C.Body height in the front, chest circumference and body weigh in group C were extremely significantly higher than that in group A and B(P< 0.01),and body high at hinter quarter in group C was significantly higher than that of group A and B(P< 0.05),while in which group A and B had no significant difference;Body length, circumference of cannon bone and birth weight in three groups had no significant difference;The order of average daily gain were A>B>C,and average daily gain in group A was extremely significantly higher than that in group B and C(P< 0.01). 2 The bigger the body size was, the greater the body weight of Xinjiang brown bulls was attained during 0-28 months of age.The growth curve of body size was coincident with the growth curve of body weight.There were extremely significantly strong correlation between every body size index with body weight(P< 0.01), which had the strongest correlation between chest circumference with body weight(r=0.996). 3 Dressing percentage, neat percentage,meet-bone ratio and meat bone ratio and yield of quality meat of Xinjiang brown bulls were much higher.The more carcass weight and eye muscle area were,the higher the yield of meat quality was during 16-22 months of fattening period.The dressing percentage, neat percentage, meat bone ratio and the weight of heart, liver, spleen, lung, kidney, tail had no significant difference between experimental cattle in three groups,and dressing percentage, neat percentage with meet-bone ratio were 57.82%、42.21%、3.27:1 respectively.There were significantly middle positive correlations between weight of tenderloin, sirloin, ribeye with carcass weight, eye muscle area(P<0.05);there were extremely significantly middle positive correlations between weight of high rib,silvery fungi,thick flank with carcass weight, eye muscle area(P<0.01). 4 Cooking loss, drip loss rate, pH value, routine nutritional ingredient, the component and content of amino acid of Xinjiang brown bulls had no significant difference during 16-22 months of fattening period,while the longer the fattening period was,the older beef was.The order of longissimus dorsi and eye muscle area were A<B<C,and the shearing force in group C was extremely significantly higher than that in group A(P<0.01),in which eye muscle area was significantly higher(P<0.05).The longer the fattening period was, the larger shearing force and eye muscle area were, the older beef was.There were 17 amino acids containing in longissimus dorsi muscle of Xinjiang brown bulls,and the content of amino acid was 21.93 g/100g,the content of umami amino acids accounted for total amino acid reached 44.05%.To sum up, chest circumference and the body length could be used as quantitative indicators to evaluate weight of Xinjiang Brown bulls; The beef yield performance of Xinjiang Brown bulls were quiet higher,and eye muscle area could be used as main indicator to evaluate beef yield performance of Xinjiang Brown bulls; The shearing force could be used as indicator to compare muscle tenderness of Xinjiang Brown bulls.