EFFECT OF PUERARIA MIRIFICE IN THAI NATIVE CROSSBREED AND BROILER CHICKENS

摘要

The experiments were conducted to study the effects of Pueraria mirifica, having estrogenic activity, as a synthetic hormone (hexoestrol) substitute for caponizing the Thai native crossbred and commercial broiler chickens. The results showed that both Thai native crossbreds (Tanao-Sri chickens) on fed powdered P. mirifica tuberous root 2 per cent in diet from 1-18 weeks of age and the broilers fed with 1 per cent P. mirifica tuberous root in diet from 3-4 weeks of age and 2 per cent P. mirifica tuberous root in diet from 5-8 weeks of age had lower testis weightp(P < 0.01) than chickens fed on a control diet (0 per cent P. mirifica), but no significant differences were found among those of chickens fed on P. mirifica tuberous root supplemented diet and chickens caponized by hormone implantation. The increasing in breast weight was found in Thai Native Crossbreds fed P. mirifica tuberous root supplemented diet (p < 0.0l). The production performance and results of the panel test namely, tenderness, flavour, and overall acceptability, did not significantly differ among chickens fed P. mirifica tuberous root supplemented diet and chickens caponized by hormone implantation. Therefore, P. mirifica could be added as a synthetic hormone substitution for caponizing chicken production, with similar cost of production. The estrogenic activity from phytoestrogen "miroestrol" residues of meat and liver from Thai native crossbreds fed on P. mirifica supplemented diets did not exceed the limit of FDA. Broilers showed rapid recovery of testis weight, testosterone level in blood of male birds, and estradiol level in blood of female birds after withdrawal of P. mirifica supplementation in diets. The 100 mg of powdered P. mirifica tuberous root (crude drug) used in caponized chicken diets would have total estrogenic activity equal to the activity of estradiol 66.55 μg. The contamination of microorganisms, yeast, mold, and heavy metals would not exceed the herbal products standard limit of Thai pharmacopoeia.