Meta Analysis Of Effects Of Diets On Metabolic Protein Conversion Efficiency And Milk Yield Of Lactating Dairy Cows

Protein nutrition has an important position in dairy production,China's protein feed resources are relatively scarce,so it is necessary to protein More rational and efficient use of resources.Studies have shown that protein utilization efficiency can be improved by changing ration ratios,but this may also have an impact on milk production performance.Effects.The first objective of this study was to investigate the effect of diets on metabolic protein conversion efficiency and cow lactation performance using meta-analysis.We expect to be able to meet the lactation needs of cows while minimizing the waste of protein resources,and to provide more rational rations for cows.reference;the second experiment aimed to establish a predictive model of metabolic protein conversion efficiency by multiple regression,which would provide a reliable model for accurate prediction of metabolic protein Conversion efficiency provides the basis.The data for this study were derived from 70 foreign core journal documents,a total of310 dietary treatments,and the production of 2006 cows'data,ensuring the quality and quantity of data sources for this study.The metabolic protein conversion efficiency in this study was the ratio of milk protein production to total metabolic protein in the small intestine.The results of linear regression studies showed that metabolic protein conversion efficiency was significantly correlated with crude protein level,metabolic protein supply,neutral detergent fiber,and metabolic protein supply of linear negative correlation(p<0.01).Metabolic protein conversion efficiency showed a significant linear positive correlation with starch level and milk yield(p<0.01).There was a significant positive linear correlation between milk production and metabolic protein supply,starch level,and dry matter intake(p<0.01).There is a trend towards a linear positive correlation between milk yield and crude protein(P=0.054).Milk yield was significantly linearly negative with neutral detergent fibers(p<0.01).It can be concluded by local weighted regression that crude protein level was 14%~15%,neutral detergent fiber level was 22%~30%,and starch level was 25%~27%that the lactation performance of dairy cows could be guaranteed at the same time when the metabolic protein conversion efficiency was also at a high level;the metabolic protein supply increased and the metabolic protein conversion efficiency decreased linearly;when the metabolic protein supply was more than 2.75kg/d,the milk yield showed a horizontal trend.Through stepwise multiple regression,we can conclude that the use of metabolic protein conversion efficiency and milk yield is the simplest multiple regression,which can accurately predict the metabolic protein conversion efficiency,the regression equation is:MPE=48.171-14.871MP+0.944MY(R~2=0.867,AIC=282.14)Metabolic protein conversion efficiency is most accurately predicted when using four factors:metabolic protein,milk yield,neutral detergent fiber,and days of lactation.The regression equation is:MPE=48.811-14.668MP+0.966MY-0.105NDF+0.011 DIM(R~2=0.884,AIC=262.88)...