Effects Of Different Diets On Production Performance And Meat Quality In Fattening Tibetan Sheep

The objective of this study was to evaluate the effects of different diets of forage to concentration rate on performance,carcass characteristics and meat quality in fattening Tibetan sheep,and find the suitable concentrate proportion to provid theoretical basis for Tibetan sheep fattening.The first experiment: Eighty body weight of 33.03±0.65(SD)kg male Tibetan sheep housed in individual pens were randomly divided into four groups(CK,Group ?,Group?and Group ?),and offered 4 finishing diets(one group per diet)that contained 70(without alfalfa hay),70,60 and 50% forage to concentrate ratio,each group had 5 repeats and each repeat offered 4 sheep.To evaluate the effects of different diets on production performance and blood physiological and biochemical parameter in fattening Tibetan sheep.The results showed that:(1)ADFI in CK and group ?was significantly higher(p<0.05)than those of group?and group ?,however,ADG in CK was the loweast and significant lower(p<0.05)than those of other three groups.The greatest feed conversion ratio(FCR)was produced by control group(30 and 70% forage to concentrate ratio),followed by group?and group?,while the smallest FCR was found in group?(50 and 50% forage to concentrate ratio).(2)As adding alfalfa hay,the concentrate of albumin and globulin in the Tibetan sheep bloon were improved in the three groups(group?,group?and group?),and compared with the control group the total protein and blobulin had extremely significant difference(p<0.01),but no significant difference between different group?and group ?(p>0.05).(3)Adding alfalfa hay in the diets increased the feeding costs,but decreased the fodder weight gain cost of Tibetan sheep,especially in group ?had the lowest cost of weight gain cost,indicating that adding alfalfa hay in 50% concentrate level feeding the Tibetan sheep on grwth performance and economic benefit is best.The second experiment: After 75 days of feeding experiment,twenty sheep(5 sheep/per treatment)were slaughtered,and carcass characteristics and meat quality were measured to research the effects of different diets on slaughter performance and meat quality of Tibetan sheep.The results showed that:(1)The body weight,slaughter rate,backfat,eye muscle area and internal organs were higher in group ?than the other groups,but the slaughter rate,back fat thickness,weight of spleen and kidney weight were extremely significant difference compared with control group(p < 0.01),however,no significant difference among the different concentrate levels(p > 0.05).(2)The effects of different diets on the longissimus dorsi muscles of dry matter,crude protein,crude fat and crude ash were not significant different,but as adding alfalfa hay the crude protein content in the group ?increased by 1.25% compared with the control group.(3)Adding alfalfa hay in diet can improve the flavor amino acid and the essential amino acids in the protein content,however,they has not significant difference(p>0.05).Various amino acids in group? with concentrate ratio was 40% had the highest content,and 12 kinds of amino acid including aspartic acid,histidine,arginine,tyrosine,alanine,cysteine,valine,methionine,isoleucine,leucine,phenylalanine and lysine had a significant difference compared with control group(p < 0.05).(4)Adding alfalfa hay in diet can increase the proportion of unsaturated fatty acid,reduce the proportion of saturated fatty acids,in which the ratio of polyunsaturated fatty acids and saturated fatty acid in test ?(0.49)and test ?(0.45)had good performance.