Effects Of Different Dietary Energy Levels On Growth Performance,Nutrients Metabolism,Digestive Enzymes Activities And Intestinal Morphology In Frizzle Chickens

The purpose of this study was to investigate the effects of different energy levels on growth performance,nutrient metabolism,digestive enzyme activity and intestinal morphology of Frizzled chicken.200 1-day-old female chicks were randomly divided into 5 groups,4 replicates in each group,and 10 chickens in each replicate.The protein content of the five diets fed with energy levels of 10.0 MJ / kg,10.8 MJ / kg,11.6 MJ / kg,12.4 MJ / kg and 13.2 MJ / kg was 19%,while other nutrition levels remained unchanged.The experimental period was 12 weeks.The results show that:1.Growth performance: At 1-4 weeks and 5-8 weeks of age,with the increase in energy levels ADG significantly increased(P<0.05),ADFI decreased significantly(P < 0.05).At 9-12 weeks old with the increase of energy level feed intake and feed conversion rate decreased significantly,ADG change was not significant.When the energy level of 1-12 w was 11.6-12.40 MJ / kg,the growth performance of each period and the whole period was the best.2.Nutrients metabolism: In 1-4 weeks,with the increase of energy level,various nutrients increased significantly.The metabolic rates of DM,GE,EE and protein increased significantly at 5-8 and 9-12 weeks,but there was no significant difference between 11.6 MJ / kg,12.4 MJ / kg and 13.2 MJ / kg groups.3.Digestive enzyme activity: At different development stages,the performance of intestinal digestive enzyme was different.At the level of energy of 10.0 MJ / kg at the age of 4 weeks,the activities of protease,lipase and amylase were the highest.At the age of 8 weeks,there was no regular change in different digestive enzymes.At the age of 12 weeks,the highest dietary energy range of various digestive enzymes is 10.0 ? 10.8 MJ / kg.4.Intestinal morphology: At the age of 4 weeks,the optimal dietary energy level of duodenal villi was 12.4-13.2 MJ / kg,jejunum was 10.8-11.MJ / kg,ileum was 11.6-13.2 MJ / kg.There was no significant difference among the groups.The suitable energy level of villus height of small intestine was 10.8-11.60 MJ / kg at 8 weeks old,and there was no regular change of villus height at 12 weeks old.Conclusion: With the increase of dietary energy level,the growth performance,nutrient metabolism rate and feed intake of Frizzled chicken increased.According to the growth performance,nutrient metabolism rate,intestinal structure and digestive enzyme activity,the long-term suitable dietary energy level for frizzled chickens is 10.8-11.6 MJ / kg.