The Appropriate Crude Protein Levels Of Beijing Youji At Egg-laying Peak Stage

The objective of the experiment was to study the appropriate crude protein levelsof Beijing YouJi Laying Hens at egg-laying peak stage and provide reference to dietaryprotein requirement in production of Beijing YouJi. Eight hundred and forty birds atthe age of32weeks were equally divided into six groups, and105birds each group.The group1was control, and the crude protein level was15.0%,and others weretreatment groups,and the crude levels were15.2%,15.4%,15.6%,15.8%and16.0%,respectively. All the birds were fed with corn-soybean based diet to43weeks.Growth performance,egg quality and blood biochemical parameters of Beijing YouJiwere determined. The results were as follows:For production performance, the average feed intake, laying rate and feed/eggratio of15.2%was much better than other groups（P<0.05）. the average egg weightshowed the protein levels of15.8%was the highest（P<0.05）. The best productionperformance for appropriate crude protein level should be15.2%.The shape index of15.2%was the best. Dietary protein level had a certain effecton the shell thickness of Beijing YouJi Laying Hen（P<0.05）and15.4%was best.The yolk color were enhanced accompanying an increase of dietary protein level and15.0%was obviously lower than other groups（P<0.05）. the haugh unit and egg yolkproportion heavy had no significant difference （P>0.05）. Comprehensive eggquality index, which is suitable for the crude protein level add content is15.2%.For blood biochemical parameters, triglyceride(TG) of different dietary proteinlevel were not significant（P>0.05）.Glucose(G)content also did not exist significantdifferences （P>0.05）.Free fatty acid(FFA) content of15.2%was significant（P<0.05）. There were no significant difference among other groups（P>0.05）.Therefore we recommend15.2%for crude protein level of egg peak Beijing YouJi.