A Nation Wide Investigation Of Feed Protein Level And Utilization In Farms

With the rapid development of pig industry,lack of feed resources and pollution problems of pig are becoming more and more serious.In order to solve this problem,the research on the low protein diet has become a hot research topic of the nutrition experts.Without the biological evaluation of feed nutrients in China,the research of low protein diets is based on the NRC standard of the United States.There are differences between us and abroad,such as breeding environment,breeding varieties feed materials and processing methods of feed.It is not practical to research low protein diet only according to NRC standard.Therefore,the main contents of this experiment is to determine the crude protein level of pig feed and digestibility in different scale of farms,and to determine the content of nitrogen compounds and microbial content in pig manure.The results of this experiment are conducted to provide actual production data for the research of low protein diets.The paper was divided into three parts:1 The investigation of crude protein and protein utilization of feed in different scale farmsThis investigation was conducted to know the differences between NRC standard and actual production,and to provide data of actual to the research of low protein.In this investigation,we investigated 55 different scale of farms in Jiangsu,Anhui,Zhejiang,Hainan and Chongqing and other areas.The results showed that at late finishing period,crude protein's content of feed in large scale farm was significantly lower than small and medium scale farm(P<0.05).There was no significant differences between crude protein of feed at other period(P>0.05).And the content of crude protein in feed at late and early finishing period was higher than the NRC standard.The results of lysine amount showed that amount of lysine at different period in all scale farms was higher than NRC standard.2 The crude protein content and protein utilization of different scale farmsThis study was conducted to determine the real crude protein content of feed,and to compare the differences between crude protein content and protein utilization of different scale farms.In this experiment,we collected the feed and fecal of 6 pigs housed in different pigsty in 9 different scale of farms.Then we determined the crude protein content of feed and the protein utilization.The results showed that all crude protein content of different farm is higher than NRC standard.The protein utilization of No.H farms at growing and finishing period is significantly lower than the other farms(P<0.05).The crude protein content of feed at small and large scale farms is no difference(P>0.05).The protein utilization at growing period of small scale farm is higher than the large scale farm(P<0.05).3 Fecal microbes and nitrogenous compounds of pigs at different scale farmThis study was conducted to determine the fecal microbes and nitrogenous compounds of pig.In this experiment,we collected the feed and fecal of 6 pigs housed in different pigsty in 9 different scale of farms.The results showed that the content of ammonia,amines,skatole and indole is no difference between small and large scale of farm(P>0.05).Real-time PCR analysis showed that 16S rRNA gene copies of bacteroidetes in fecal of small scale farm significantly lower than the large scale farm(P<0.05),and the 16S rRNA gene copies of Clostridium cluster ??a is significantly higher(P<0.05).There wassignificant connection between methylamine and bacteroidetes at growing period(P<0.05).And the content of methylamine also had significant connection with Clostridium cluster ??a at finishing period(P<0.05).