With the rapid development of China's dairy industry,the yield and scale of dairy cows have gradually increased,and the total mixed ration(TMR)technology has been widely applied in pastures.The seven large-scale p...With the rapid development of China's dairy industry,the yield and scale of dairy cows have gradually increased,and the total mixed ration(TMR)technology has been widely applied in pastures.The seven large-scale pastures in the Heilongjiang reclamation area were selected.The area was divided into high milk yield pastures(A,E,F and G)and low milk yield pastures(B,C and D).The nutritional contents of TMR of the seven pastures were compared with NRC(2001)recommendations.The results showed that in the high milk yield pastures,the crude protein(CP)contents were closer to NRC recommendations(2001)than those of the low milk yield pastures,and the contents of ether extract(EE)were significantly higher(P<0.05).The contents of acid detergent fiber(ADF)in TMR of all the scale pastures were close to those recommended by NRC(2001),where as the contents of neutral detergent fiber(NDF)were significantly higher than the NRC(2001)recommendations.After measuring the dry matter(DM)rumen degradation rates,CP,NDF and ADF of TMR of dairy cows on the ranch were assessed using the nylon bag method,CP contents of the high milk yield pastures were significantly higher(P<0.05)compared with those of the low milk yield pastures,and the rumen degradable protein(RDP)to rumen undegradable protein(RUP)ratio was more ideal.The diets in the high milk yield pastures had significantly higher NDF contents and degradation rates than those in the low milk yield pastures,except pasture D(P<0.05).The diets in pastures E and G(with higher milk yields)had higher ADF degradation rates than pastures B,C and D,which had lower milk yields(P<0.05).Additionally,the type and digestibility of roughage were also related to dairy cows'performance.In summary,dairy cow performance was positively correlated with the nutrition of TMR.By exploring the quality of TMR from the aspects of TMR's nutritional contents,rumen degradation rates and feed ingredients,this study provided a reference for the evaluation of TMR nutrition.展开更多
文摘With the rapid development of China's dairy industry,the yield and scale of dairy cows have gradually increased,and the total mixed ration(TMR)technology has been widely applied in pastures.The seven large-scale pastures in the Heilongjiang reclamation area were selected.The area was divided into high milk yield pastures(A,E,F and G)and low milk yield pastures(B,C and D).The nutritional contents of TMR of the seven pastures were compared with NRC(2001)recommendations.The results showed that in the high milk yield pastures,the crude protein(CP)contents were closer to NRC recommendations(2001)than those of the low milk yield pastures,and the contents of ether extract(EE)were significantly higher(P<0.05).The contents of acid detergent fiber(ADF)in TMR of all the scale pastures were close to those recommended by NRC(2001),where as the contents of neutral detergent fiber(NDF)were significantly higher than the NRC(2001)recommendations.After measuring the dry matter(DM)rumen degradation rates,CP,NDF and ADF of TMR of dairy cows on the ranch were assessed using the nylon bag method,CP contents of the high milk yield pastures were significantly higher(P<0.05)compared with those of the low milk yield pastures,and the rumen degradable protein(RDP)to rumen undegradable protein(RUP)ratio was more ideal.The diets in the high milk yield pastures had significantly higher NDF contents and degradation rates than those in the low milk yield pastures,except pasture D(P<0.05).The diets in pastures E and G(with higher milk yields)had higher ADF degradation rates than pastures B,C and D,which had lower milk yields(P<0.05).Additionally,the type and digestibility of roughage were also related to dairy cows'performance.In summary,dairy cow performance was positively correlated with the nutrition of TMR.By exploring the quality of TMR from the aspects of TMR's nutritional contents,rumen degradation rates and feed ingredients,this study provided a reference for the evaluation of TMR nutrition.
