Effect Of Diet Supplemented With Isoflavone On The Performance In Broilers And Laying Hens And Endocrine Mechanisms Involved

Broilers and laying hens were used to study the effect of three kinds ofisoflavones(daidzein,ipriflavone and genistein) on production performance.Throughobserving the effect of diet supplemented with isoflavones on the productionperformance, endocrine and lipids metabolism, in order to discuss effect mechanismof isoflavones on broilers and laying hens, to provide theory foundation on theapplication of isoflavones in stockbreeding.1.Effect of daidzein and ipriflavone on the growth performance in broilers800 Ai-Wei-Yin broilers of 1-day-old were randomized into 8 groups according tooriginal weight:basal diet, basal diet plus 3mg/kg,5mg/kg,10mg/kg daidzein, basaldiet plus 3mg/kg,5mg/kg,10mg/kg ipriflavone,basal diet plus 2.5mg/kg daidzein and2.5mg/kg ipriflavone, the test lasted for 6 weeks, then slaughtered 10 cockerel chicksand 10 female chicks in control,5mg/kg daidzein,5mg/kg ipriflavone and 2.5mg/kgdaidzein +2.5mg/kg ipriflavone group respectively. The results showed that: differentdose of isoflavones presented diverse results on growth, 3mg/kg and 5mg/kg groupsaccelerated growth, the effect of 5mg/kg was better,3 test groups increased the bodyweight gain by 11.73% (P＜0.05), 10.21% (P＜0.05) and 14.43% (P＜0.05)respectivelycompared with control group, decreased ratio of feed intake and meet,enhanced feedtranslation,thereinto, the effect of daidzein was better than ipriflavone, daidzein+ipriflavone was the best of them; 10mg/kg group restrained the growth of broilers.Compared with control group, to cockerel chick,5mg/kg daidzein,5mg/kgipriflavone and 2.5mg/kg daidzein +2.5mg/kg ipriflavone groups could enhancedressing percentage,lean meat percentage, the ration of RNA and DNA, decreaseabdominal fat percentage, increase the concentration of T₃,FT₃,FT₄ and decreaseT₄,uric acid,total cholesterol,triglycerides,free fatty. To female chick, daidzein hadno obvious effect, ipriflavone and daidzein + ipriflavone had a certain effect,but thedifference were not significant compared with control group. 2.Effect of daidzein,ipriflavone and genistein on the growth performance inbroilers400 Yi-Sa laying hens of 40-week-old were randomized into 4 groups: basaldiet,basal diet plus 6mg/kg daidzein,basal diet plus 6mg/kg ipriflavone,basal dietplus 6mg/kg genistein, the test lasted for 6 weeks.The results showed that: three kindsof isoflavones could enhance egg production, decrease the ratio of feed intake andegg, the effect of daidzein was the best of them, compared with control group, eggproduction was increased by 5.1% (P＜0.05), the ratio of feed intake and egg wasdecreased by 6.3% (P＜0.05),had no effection on egg weight. Daidzein,ipriflavoneand genistein could increase serum E2 by 30.97% (P＜0.05),14.30% (P＞0.05) and19.05% (P＞0.05) respectively, daidzein and ipriflavone could increase serum Leptinby 43.66% (P＜0.05) and 23.34% (P＜0.01),increase the concentration of T₄,FT₄ anddecrease T₃,FT₃ in serum. Genistein could increase the concentration of FT₄ anddecrease T₃.Three kinds of isoflavones could decrease the concentration of totalcholesterol, triglycerides and free fatty in serum, and daidzein decreased egg yolkcholesterol concentration a certain extent during the experiment.The concentration ofdaidzein in feed and serum was 17.58ug/g,0.70ug/ml, and that in the yolk of 0,2,4,6 weeks was 1.82,2.98,4.87,3.83ug/g, detected by RPHPLC.The results of test showed that: daidzein and ipriflavone could accelerate thegrowth of broilers, enhance the feed utilization, regulate lipids metabolism, reduce theaggradation of lipids in the body, improve lean meat percentage and meat quality. Inthe practice, make suggestion of 5mg/kg, the effect of daidzein + ipriflavone wasbetter.