Effects of synchronizing starch and protein degradation on rumen fermentation, nutrient digestion and production performance in dairy cows

摘要

Introduction The goals of ruminant protein nutrition are to provideadequate amounts of RDPforoptimal ruminal efficiency and to obtain the desired animalproductivity with a minimum amount of dietary CP (NRC,2001).Non-excessive N supply to the animal becomes more important since the amounts of N excreted in animal manure have increased markedly during recent decades,causing unacceptable air and water pollution (Hristov et al.,2005).Rumen microbes use carbohydrates as the main energy sources.If the rate of protein degradation exceeds that of carbohydrate fermentation,large quantities of N are converted into ammonia,and likewise,when the rate of carbohydrate fermentation exceeds that of protein degradation,inefficient microbial protein synthesis (MPS) may occur (Bach et al.,2005).The objectives of this study were to investigate the effects of synchronizing starch and protein degradationon rumen fermentation,nutrient digestion and production performance in dairy cows.