Effects Of Different Egg Yolk Powder Levels On Growth Performance,Digestive Enzyme Activity And Blood Biochemical Indexes Of Chicks

In order to explore the effects of different egg yolk powder levels on growth performance,digestive enzyme activity and blood biochemical indexes in chicks,1 to 25 day-old chicks were selected in three experiments.Test one:effects of different egg yolk powder levels on growth performance in chick.360 one-day-age chicks were randomly divided into four groups with 3 replicates. Each one in treatment groups was fed with 0.4g,0.8g and 1.2g every day.The control group was fed with normal diet. The experiment lasted for 25 days.The results showed that with the increasing amount of yolk powder,average daily feed intake increased first and then decreased,daily feed intake of second group was maximum,which was significantly higher than that of control group;daily gain of experiment groups were significantly higher than that of control group; feed/gain,death and culling rate of second group was significantly lower than that of control group.Overall,the best growth performance was that of second group with 0.8g egg yolk powder.Test two:effects of different egg yolk powder levels on digestive enzyme activity in chicks. The treatment of this test is the same as the test one. The results showed that egg yolk powder improve intestinal protease activity, the highest protease activity was that of second group. At the age of 5,20 and 25 days, the descending order of protease activity of different bowels was jejunum>duodenum>ileum>cecum; at the age of 10 and 15 days, jejunum> ileum> duodenum> cecum. Egg yolk powder improve intestinal amylase activity,the high amylase activity was that of first and second group. At the age of 5 days,the descending order of amylase activity of different bowels is ileum> jejunum> duodenum>cecum; at the age of 10 days,jejunum>ileum>cecum>du-odenum; at the age of 15,20 and 25 days, jejunum> ileum>duodenum>cecum. Egg yolk powder improve intestinal lipase activity,the highest lipase activity was that of second group,the descending order of lipase activity of different bowels was jejunum>ileum>duodenum>cecum.Digestive ability of protein,starc-h and fat in different bowels was different,the highest digestive ability was that of jejunum.Test three:effects of different egg yolk powder levels on blood biochemical indexes. The treatment of this test is the same as the test one. The results showed that high-density lipoprotein cholesterol of experiment groups increased,low-density lipoprotein decreased,the second group was significantly different from control group;total protein and albumin increased significantly,immunoglobulin G in second group was significantly higher than that of control group.To sum up,diet with 0.8g egg yolk powder improve growth performance of chicks,enhance intestinal protease,amylase and lipase activity,improve immunity and survival rate.