A Meta-Analysis Of The Effects Of Dietary Digestible NDF On Dry Matter Intake And Production Performance Of Lactating Dairy Cows

In ruminant diets,the right amount of fiber added can increase productivity,and excess fiber limits feed intake,which reduces the amount of milk that affects economics.Dietary NDF content and total intestinal NDF digestibility are dietary nutrient parameters.In the past studies,various confounding factors such as dietary nutrient content,mineral content and dietary ratio were all related to lactating cow DMI.And the production performance has a function of adjustment and improvement,which blurs the effect of the whole intestinal NDF digestibility on the performance of dairy cows.To further investigate the physiological effects of digestible NDF on ruminants,this study used a meta-analysis method to compare the effects of dietary NDF digestibility on dairy cow DMI and production performance in 64 trials and 244 diet treatments.The research used in the analysis contains more than 10 research results before the team.The rest of the literature is published in foreign languages,which guarantees the source of the article and the quality of the test data.The results showed that there was a significant linear positive correlation between dietary NDF digestibility and DMI(P<0.01),and a significant linear positive correlation with milk production(P<0.01)and milk fat content(P<0.01).NDF digestibility There was no significant linear relationship with 4%4%fat corrected milk(P=0.08),lactose content(P=0.37),milk fat production(P=0.56),milk protein production(P=0.88),and lactose production(P=0.28).In this study,NDF digestibility changes by 1%,DMI and milk yield increased by 0.1 kg/d(R_M~2=0.08,R_C~2=0.84)and 0.19 kg/d(R_M~2=0.05,R_C~2=0.96).(R_m~2denotes R~2 when only fixed effects are considered;R_c~2 denotes R~2 when both fixed effects and random effects are considered).There is also a correlation between NDF digestibility and other nutrient digestibility.There was a significant positive correlation between NDF digestibility and DM digestibility(P<0.01).NDF digestibility was not significantly linear with organic digestibility(P=0.15),NDF digestibility increased by 1%,and DM digestibility increased.0.27%(R_M~2=0.29,R_C~2=0.78).As the digestibility of dietary NDF increases,the fiber remains less in the rumen and requires a larger DMI to fill the rumen,so DMI increases and milk production increases.In this study,the digestibility of NDF can be used as a reference for the evaluation of dietary nutrition value by meta-analysis.It has a certain regulation effect on lactating cow DMI,milk yield and milk quality.