2种营养水平下不同遗传基础肉牛对日粮养分消化率的比较研究

Comparative Studies on the Dietary Nutrient Digestibility of Different Genetic Basis Beef Cattle during Two Nutrient Levels

The experiment aimed to study the difference on the dietary nutrient digestibility of different genetic basis beef cattle during two nutrient levels.Forty-eight heads of different genetic basis beef cattle （Charolais×Simmental-crossbred cattle,Gelbvieh×Simmental-crossbred cattle,Angus×Simmental-crossbred cattle and Limousin×Simmental-crossbred cattle) were introduced，feeding two different nutritional level of diets，adopting 4×2 two factor design，and carrying on the seven days of digestion experiment using endogeny indicator method.The results showed as follows：①From genetic basis，crude protein digestibility in Gelbvieh×Simmental-crossbred cattle was significantly higher than that in Angus×Simmental-crossbred cattle (P＜0.05)，and extremely significantly higher than that in Limousin×Simmental-crossbred cattle（P<0.01）, crude fat digestibility in Gelbvieh×Simmental-crossbred cattle was extremely significantly higher than that in Charolais×Simmental-crossbred cattle and Angus×Simmental-crossbred cattle (P＜0.01).②From nutritional level，the nutrient digestibility of beef cattle in feeding a high nutrition diet were extremely significantly higher than that in feeding a low nutrition diet (P＜0.01).③From the interaction of genetic basis and nutritional level，nutrient digestibility decreased with the increase of nutritional level of diet in Charolais×Simmental-crossbred cattle,Angus×Simmental-crossbred cattle and Limousin×Simmental-crossbred cattle，while Gelbvieh×Simmental-crossbred cattle were on the contrary.The results indicated that genetic basis had significant influences on crude protein digestibility and crude fat digestibility （P＜0.05），nutritional level of diet had significant influences on the digestibility of dry matter，organic matter，crude protein，crude fiber，crude ash and crude fat （P＜0.05），crude protein digestibility were influenced significantly by genetic basis and nutritional level of diet at the same time （P＜0.05）.