Effects Of Different PeNDF Value Of Common Roughages On Rumen Degradation In Sheep

The thesis mainly selected appropriate peNDF value of roughages to make pellet feeds of sheep diet by determining the nutritive components of 8 common roughages,and analysizing the effects of different peNDF values on rumen degradation.First,the nutritional composition of different roughages was evaluated by the approximate nutrient analysis.Then the peNDF value of four different particle size and 8 kinds of feed was determined by Pennsylvania sieve.Finally,the effect of different peNDF values on the degradation characteristics of roughages was conducted by nylon bags in the rumen.The paper developed to investigate the difference of rumen dynamic degradation to different peNDF value in sheep.Trial l,determination of nutrient components of different roughages.The nutritional components of two kinds of common roughage in Inner Mongolia and Henan province were analyzed by approximate analysis method.It includes 4 kinds of gramineous feed(oat grass,leymus chinensis,rice straw,corn straw),and 4 kinds of leguminous feed and flax feed(alfalfa,peanut seedling,soybean peel,flax stalk).The results showed that alfalfa had the highest nutritional value,abundant protein,Ca,P content and low fibre content.In addition,alfalfa had excellent degradation efficiency in rumen.It was a high-quality forage feed with rich nutrition and high utilization.Although the nutrient content of soybean peel is relatively low,but it is easy to degradation,high utilization,low cost and more practical.Trial 2,effects of different peNDF value of forage on rumen degradation in sheep.The peNDF values of 4 different particle sizes and eight roughages were determined by Pennsylvania sieve.Three Mongolian sheep with good body condition,similar body weight and permanent rumen fistula were selected as experimental animals.The degradation characteristics of dry matter,protein,neutral detergent fiber and acid detergent fiber at different peNDF levels of roughages in rumen were studied by nylon bags.The suitable peNDF value for each feed were selected.The results showed that:(1)effect of peNDF value on rumen degradation was more reflected in dry matter and fibers,but the degradation of CP had no obvious influence when peNDF value changed.With the decrease of peNDF value,rumen degradation of DM,NDF and ADF increased first and then decreased.(2)Under the conditions of this trial,oat grass,leymus chinensis,rice straw,corn straw and other gramineous plant had the highest degradation when they were crushed to 1 mm;alfalfa,peanut seedling,soybean peel,flax stalk and other leguminous plants and flax plants had better degradation when they were crushed to 3 mm.