摘要
本试验旨在探究40～90 kg牦牛犊牛能量代谢规律及需要量.选取35头健康、体重相近的(60±3)日龄牦牛犊牛(公),分为3组,分别为初期屠宰组(IS组,7头)、中期屠宰组(MS组,7头)、末期屠宰组(FS组,21头),而FS组又分为自由采食组(AL组,21头)、70％采食组(IR70组,21头)和40％采食组(IR40组,21头).预试期30 d,正试期90 d.AL组、IR70组和IR40组牦牛犊牛分梯度饲喂基础饲粮.当IS组、MS组、AL组牦牛犊牛体重分别达到48、64、88 kg时,5组各选择5头牦牛犊牛进行屠宰.在试验结束前2周进行消化代谢试验和气体代谢试验.结果表明:1)AL组的终末体重、平均日增重和平均日采食量显著高于IR70组和IR40组(P＜0.05).2)AL组的粗蛋白质、粗脂肪、中性洗涤纤维和酸性洗涤纤维表观消化率显著高于IR70组和IR40组(P＜0.05),AL组的总能、粪能、代谢能和消化能显著高于IR70组和IR40组(P＜0.05),AL组和IR40组的总能消化率、总能代谢率显著高于IR70组(P＜0.05).3)AL组和IR70组的氧气消耗量、二氧化碳产生量显著高于IR40组(P＜0.05).3组之间呼吸熵和甲烷产生量无显著差异(P＞0.05),呼吸熵在0.65～0.80.4)组织中能量含量从高到低为:脂肪＞肌肉＞血液+内脏＞皮＞骨骼＞毛.5)40～90 kg牦牛犊牛平均日增重在100～500 g/d的生长净能需要量为1.37～8.10 MJ/d,生长净能需要量的模型为:log10能量=0.830 9+1.232xlog10空腹体重.维持净能需要量的回归方程为:log10产热量=0.000 138x代谢能摄入量+2.573,维持净能需要量为374.10 kJ/kg SBW0.75.综上得出,40～90 kg牦牛犊牛气体代谢的呼吸熵为0.65～0.80,维持净能需要量为374.1 kJ/kg SBW0.75,平均 日增重在100～500 g/d的生长净能需要量为1.37～8.10 MJ/d,补充了饲养标准中牦牛犊牛营养需要的基础参数.
Abstract
The purpose of this experiment was to explore the energy metabolism rule and requirement of 40 to 90 kg yak calve.Thirty-five healthy(60±3)-day old yak calves(male)with similar body weight were divided into 3 groups,namely the initiation slaughter group(IS group,7 calves),middle slaughter group(MS group,7 calves)and final slaughter group(FS group,21 calves),while the FS group was subdivided into the ad li-bitum feeding group(AL group,7 calves),70％feeding group(IR70 group,7 calves)and 40％feeding group(IR40 group,7 calves).The pre-experimental period lasted for 30 days,and the experimental period lasted for 90 days.The yak calves in AL group,IR70 group and IR40 group were fed the basal diets in a gradi-ent manner.When the body weight of yak calves in IS group,MS group and AL group reached 48,64 and 88 kg,5 yak calves in each of the 5 groups were selected for slaughter.The digestive metabolism experiment and gas metabolism were conducted before two weeks of the experiment end.The results showed as follows:1)the final body weight,average daily weight gain and average daily feed intake of AL group were significantly high-er than those of IR70 group and IR40 group(P＜0.05).2)The apparent digestibility of crude protein,crude fat,neutral detergent fiber and acidic detergent fiber of AL group were significantly higher than those of IR70 group and IR40 group(P＜0.05),the gross energy,fecal energy,metabolic energy and digestive energy of AL group were significantly higher than those of IR70 group and IR40 group(P＜0.05),and the gross energy digestibility and gross energy metabolic rate of AL group and IR40 group were significantly higher than those of those of IR70 group(P＜0.05).3)The oxygen consumption and carbon dioxide production of AL group and IR70 group were significantly higher than those of those of IR40 group(P＜0.05).There were no significant differences in methane production and respiratory entropy among the three groups(P＞0.05),and the respira-tory entropy ranged from 0.65 to 0.80.4)The energy contents in tissues from high to low was:fat＞muscle＞blood+viscera＞skin＞bone＞hair.5)For 40 to 90 kg yak calves,the net growth energy requirement with av-erage daily gain of 100 to 500 g/d was 1.37 to 8.10 MJ/d,and the model of growth net energy requirement was:log10 energy=0.830 9+1.232xlog10 empty body weight.The regression equation for maintaining net ener-gy requirement was:log10 heat production=0.000 138×metabolic energy intake+2.573,and the maintaining net energy requirement was 374.1 kJ/kg SBW0.75.In summary,it was concluded that the respiratory entropy of gas metabolism of 40 to 90 kg yak calves range from 0.65 to 0.80.the maintaining net energy requirement is 374.1 kJ/kg SBW0 75,the growth net energy requirement with average daily gain of 100.00 to 500.00 g/d is 1.37 to 8.10 MJ/d,which filled in the basic parameters for nutritional needs in feeding standards of yak calves.[Chinese Journal of Animal Nutrition,2024,36(4):2512-2523]
基金项目
国家自然科学基金(32260853)
青海省中央引导地方科技发展资金项目(2023ZY017)
维普
万方数据