Study On CPM Evaluation Of Nutritional Value And Performance Of Dairy Cattle Diet

Feed prices vary greatly with time and region.The biggest difference between ruminants and monogastric animals is that ruminants have a complex foregastric system.Microorganisms in the rumen can convert different feed components into volatile fatty acids,microbial proteins and other nutrients,which can be absorbed and utilized by the body.CPM software has a powerful database.Once input feed composition,animal status and surrounding environment,it will accurately predict dairy cattle's metabolic index and production performance.In this way,CPM is very helpful Software for dairy farm management and formula control,especially cost control.Therefore,this experiment used CPM to predicate feed's net lactation energy and metabolic protein and kept effective indictors in the same level,in this way to study the effect of different feed components on dairy cattle's production performance.CPM software was used to design four formulations with the same level of lactation net energy and metabolic protein.The coefficient of variation of lactation net energy,metabolic energy,metabolic protein in different treatment groups were less than 1%.The above results showed that the four groups had different dietary components,but the effective nutritional indicators were the same.The results showed that the pH,ammonia nitrogen,VFA,acetic acid concentration,propionic acid concentration,butyric acid concentration,valeric acid concentration and ethylene-propylene ratio of rumen were not significantly affected by different dietary formulations(P > 0.05).With the increase of starch gradient,the insulin,beta-hydroxybutyric acid and blood sugar did not change significantly(P > 0.05).There was no significant difference in total cholesterol,triglyceride and free fatty acid among the four groups(P > 0.05).The results showed that the changes of dietary starch and other nutrients had no significant effect on the blood biochemical indexes of dairy cows when the lactation net energy and other effective nutrients were similar.Four diets with different dietary components but same net lactation energy had no significant effect on dry matter intake,milk yield,milk fat corrected milk and energy corrected milk(P > 0.05).Dietary composition had no significant effect on the milk fat,milk protein and lactose yield(P > 0.05).Dietary composition had no significant effect on lactation performance(P > 0.05).The actual milk yield was 22.30-23.60 kg/d,which was not significantly different from the milk yield predicted by MP(P > 0.05),but significantly different from the milk yield predicted by ME(P < 0.05).Dietary structure had no significant effect on microbial diversity and richness(P > 0.05),but had effect on microbial.The results showed that Prevotella and Bacteroides increased first and then decreased with the increase of starch(P < 0.05).The results showed that the net energy of lactation and metabolic protein in diet were at the same level,and the change of feed composition would not affect milk and Cattle production performance.