Effects of Feeding the Pelletized Cornstalk Diet on the Digestion and Metabolism of the Rumen and Whole Body in Sheep

Four of Small Tail Han Sheep ram with permanent rumen fistula,about 2years old,with body weight of(57.3±5.6)kg,were fed with the diets of the pelletized or ground(as control)cornstalk diets(concentrate∶roughage=28∶72).By 2×2cross-over design,the rumen liquid was collected at 0,1.5,3.0,5.0,7.0,and 10hafter feeding and the digestion and metabolism experiment of whole body was carried on,to study the effect of feeding pelletized cornstalk diet on the intake,digestion and metabolism of sheep.The results showed that by feeding pelletized diet,the voluntary intake of dry matter was increased by 34.9%(P 0.01);the NH3-N and TVFA of rumen fluid on average were decreased by 8.7%(P0.05) and 11.6%(P 0.05)respectively;the rumen protozoa was decreased by 10.0%(P 0.05);the total bacteria of rumen were increased by 9.9%(P 0.01);the fungi copies were increased by 2.9%(P 0.05);the volume and turnover of rumen fluid were increased by 22.7%(P 0.01)and 18.4%(P 0.01) respectively.When the pelletized diet was fed,the apparent digestibility of organic matter,crude protein and cellulose was decreased by 11.5%(P0.01),5.1%(P0.05)and 9.9%(P0.05)respectively,however,the digested amounts were increased by 21.1%(P0.01),29.2%(P0.01)and 17.8%(P0.05)respectively.The nitrogen,calcium and phosphorous retentions of sheep were increased by 21.5%(P 0.01),14.7%(P 0.05)and 18.5%(P 0.01)respectively,compared with the ground diet.It is concluded that the feeding pelletized diet could greatly increase the voluntary intake of sheep,increase the digested amount of nutrients and the nitrogen retention of sheep,but significantly decrease the digestibility of diet;by feeding pelletized diet,the rumen protozoa was decreased,the total bacteria of rumen fluid was increased,and the NH3-N and TVFA of rumen fluid had a tendency to decrease;however,because of the increase of the volume and turnover of rumen fluid,the total amounts of protozoa and fungi were possibly increased.This experiment showed that feeding cornstalk pelletized diet may be an effective method for improving sheep nutrition.