Effects of Different Relative Feeding Levels on Growth Performance,Slaughter Performance and Organ Development of Tibetan Gamba Sheep
The purpose of this experiment was to study the characterization of growth performance,slaughter performance and organ development of Tibetan Gamba sheep under different relative feeding levels,so as to e-valuate the production value of Tibetan Gamba sheep.Thirty-six healthy male black Gamba sheep lambs with the same body condition and body size[average body weight(BW):(17.94±0.91)kg]were selected and randomly divided into 6 groups with 6 replicates per group and 1 sheep per replicate.According to the metabo-lizable energy and protein maintenance requirements of sheep in NRC(2007),the dietary metabolizable energy and protein levels of each group were designed with different multiples.Group Ⅰ:0.8 times of requirement for 20 kg BW and 100 g/d average daily gain(ADG);group Ⅱ:0.9 times of requirement for 20 kg BW and 100 g/d ADG;group Ⅲ:1.0 times of requirement for 20 kg BW and 100 g/d ADG;group Ⅳ:0.8 times of requirement for 20 kg BW and 200 g/d ADG,group Ⅴ:0.9 times of requirement for 20 kg BW and 200 g/d ADG;group Ⅵ:1.0 times of requirement for 20 kg BW and 200 g/d ADG.The pre-trial period lasted for 10 days and the experimental period lasted for 70 days.The results showed as follows:the final body weight,net gain,average daily gain of sheep in groups Ⅴ and Ⅵ had no significant differences(P＞0.05),while groupⅥ was significantly higher than the other 5 groups(P＜0.05);the ratio of feed to gain in group Ⅰ was signifi-cantly higher than that in the other 5 groups(P＜0.05);the feed cost increased significantly with the increase of relative feeding level(P＜0.05).Live weight before slaughter,carcass weight and net meat weight in groupⅥ were significantly higher than those in the other 5 groups(P＜0.05),while the live weight before slaughter in groups Ⅲ and Ⅴ had no significant difference(P＜0.05),but they was significantly higher than that in groups Ⅰ,Ⅱ and Ⅳ(P＜0.05);there was no significant difference in net meat weight among groups Ⅲ,Ⅳand V(P＞0.05),but they was significantly higher than groups Ⅰ and Ⅱ(P＜0.05);the abdominal fat weight of group Ⅵ was significantly higher than that of groups Ⅰ,Ⅱ and Ⅴ(P＜0.05).The liver weight and index of group Ⅵ were significantly higher than those of the other 5 groups(P＜0.05);there were no signifi-cant differences in heart,lung and kidney weights and indexes among the 6 test groups(P＞0.05);the weight and index of rumen of group Ⅵ were significantly higher than those of the other 5 groups(P＜0.05),and the weights and indexes of reticulum and omasum were significantly higher than those of groups Ⅱ and Ⅳ(P＜0.05).In conclusion,combined with feed cost and actual breeding economic benefits,it is recommend that di-et prepared according to 0.9 times the metabolizable energy and protein maintenance requirements of sheep with 20 kg BW-200 g/d ADG in NRC(2007),Tibetan Gamba sheep can obtain the better growth performance and slaughter performance.[Chinese Journal of Animal Nutrition,2024,36(8):5207-5216]
万方数据
维普
