Effect And Mechanism Of Diet Adding Enzyme Preparation After Egg Laying Peak

This study investigated the effects and mechanism of different dietary enzyme levels after laying peak, analysis of the performance of laying hens changes in antioxidant function, immune function, gastrointestinal environment and microbial flora change. 540 healthy 37 weeks Highland brown egg layer were randomly allocated into 4 treatment groups: (A) basal diet (control group); (B) basal diet + 0.1% enzyme preparation; (C ) basal diet + 0.2% enzyme preparation; (D) basal diet supplemented with 0.3% enzyme preparation. A period of 56 d in the feeding trial.The results showed that:1. complex enzyme in peak egg production performance of laying hensDifferent levels of dietary enzyme complex on the late peak laying rate, had no significant effect of egg weight(P> 0.05); had no significant effect on the egg shape index, yolk weight, egg shell thickness, Hastelloy Unit (P> 0.05); complex enzyme was not significant(P> 0.05) on the egg ration.2.enzyme preparation on the the intestinal morphology after laying peak of hensAdding different levels of dietary enzyme was not significant on the intestinal villi height of laying hens (P> 0.05). Improved the intestinal enzyme complex V / C value (P <0.05), crypt depth shallower (P> 0.05), with the enzyme level increased V / C increase and the trend of recess. Enzyme also had the trend of reducing the wall thickness, high enzyme levels may cause bowel wall thickness.3.enzyme preparation on the relative weight of intestine of hens afer laying peakDietary enzyme had no significant difference (P>0.05) for 41 and 45 weeks hen,s relative weight of digestive tract layers; 41 weeks, significantly reduced the relative length of the jejunum (P <0.05), 0.3 % of the added level reduced maximum amplitude; 45 weeks, the enzyme can significantly improve the relative length of the jejunum (P <0.05).4. enzyme preparation on the pH of intestinal contents of laying hens after laying peak41 weeks,there were no significant difference on muscular stomach, duodenum, jejunum, ileum and cecum pH (P > 0.05), 41 weeks, increased muscular stomach, cecum pH, lower duodenum, jejunum and ileum pH. 45 weeks , there were no significant difference on muscular stomach, duodenum, jejunum, ileum and cecum pH (P > 0.05), increased muscular stomach, ileum, and cecum pH. 5.enzyme preparation on the total protease activity of intestinal of laying hens after laying peakEnzyme increased 41,45 weeks laying hens muscular stomach, duodenum, jejunum and ileum of the total protease activity (P <0.05). 0.3% enzyme levels compared with the control group, significantly increased 41,45 weeks laying hens muscular stomach, duodenum, jejunum and ileum of the total protease activity (P <0.05).6.enzyme preparation on the microflora of intestinal contents and faecal of laying hens after laying peakEnzyme preparations can reduce the number of Escherichia coli in the cecum and feces, increased cecal and fecal flora in the number of lactic acid bacteria. 41 weeks, 0.3% level can significantly reduce the number of coliform bacteria in the cecal content, significant differences (P <0.05).0.2 % of the added level can significantly reduce the amount of fecal coliform, and difference significantly (P <0.05). 47 weeks of age, 0.2 %, 0.3 % of the added level can significantly increase the number of colonies of lactic acid bacteria in feces, and the difference is significant (P <0.05).7. enzyme preparation on the serum antioxidant enzymes and major metabolic hormone levels of laying hens after laying peakThe level of dietary enzyme layers with lower serum glutathione peroxidase (GSH-px) content and increased superoxide dismutase (SOD) trend. 41 weeks, significantly increased total antioxidant capacity (T-AOC) levels (P <0.05); had no significant difference layers of serum GSH-px, SOD, T-AOC ( P > 0.05) of serum .GH, T3 and T4 were not significantly affected (P> 0.05).8. enzyme preparation on the immune parameters of laying hens after laying peak41 weeks, 0.2% and 0.3% of the added levels increased Newcastle disease (ND) antibody titers, the difference was significant (P <0.05); 0.1% and 0.3% adding level increased avian influenza (H9) antibody titers, the difference was significant (P <0.05). 45 weeks, 0.2% and 0.3 % and the control group, increased antibody titer to Newcastle, the difference was significant (P <0.05); improve the avian flu (H9) antibody titers, but the difference was not significant (P> 0.05).Conclusion: The results showed that: laying hens after peak, the overall balance in the nutrition diet add complex enzyme, the improvement of their economic effect is not obvious . Main reason: The economic characteristics of laying hens by dietary factors and changes decreased the sensitivity than the peak of egg production significantly, compensatory stronger, diets supplemented with enzyme preparation had no significantly improvement. The digestive tract of the environment and form layers, antioxidant capacity and major metabolic hormones. Even raising the layers of intestinal protease activity, immune function, reducing the amount of harmful bacteria, but these effects on health in terms of laying hens, but had no effect of improving production performance. Therefore, in the production practice of feeding ,nutritionally balanced diet routine after the laying hen egg production peaks, add complex enzyme is questionable.