|Dowd, Michael - Mike|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/22/2006
Publication Date: 3/1/2007
Citation: Lordelo, M.M., Calhoun, M.C., Dale, N.M., Dowd, M.K., Davis, A.J. 2007. Relative toxicity of gossypol enantiomers in layers and broiler breeder hens. Poultry Science. 86(3):582-590. Interpretive Summary: Interpretive Summary: Gossypol, a polyphenolic pigment found in cottonseed in both a (+)-form and a (-)-form, was added to poultry meals to study the compound’s effect on egg production. Feeding experiments were conducted with (+)-gossypol, (-)-gossypol, and with a 50/50 mixture of the two forms. Feed consumption, bird weight, egg production, egg discoloration, and the levels of gossypol in eggs and various animal tissues were determined over 20 days of feeding with the gossypol supplements. The addition of (+)-gossypol reduced egg production and increased the percentage of eggs with severe yolk discoloration. When fed in the same concentration, the (+)-form was found in higher concentration that the (-)-form in most internal tissues. These and prior results indicate that both forms of gossypol affect poultry growth but that the (+)-form is much more detrimental to egg production and egg quality that the (-)-form. The results should be of interest to poultry producers and researchers working to incorporate cottonseed and cottonseed meal into poultry rations.
Technical Abstract: Abstract: Gossypol, a natural component of cottonseed meal, exists in either a positive (+) or a negative (-) enantiomeric form. Two experiments were conducted to determine the relative toxicity of the individual gossypol enantiomers in laying and broiler breeder hens. In the first experiment, 25 individually caged Hy-Line W36, 43-wk-old, laying hens were fed a standard diet supplemented with either no gossypol or the individual enantiomers at 200 and 400 mg/kg of diet for 20 d (5 hens/treatment). In experiment 2, 15 individually caged Cobb 500 fast feathering, 44-wk-old, broiler breeder hens were fed a standard diet supplemented with either no gossypol or the individual enantiomers at 400 mg/kg of diet for 18 d (5 hens/treatment). In both experiments, feed intake, egg production and egg weight were determined daily. All eggs were individually opened and scored for yolk discoloration. At the end of both experiments, several organ and tissue samples were collected for gossypol analyses. In both experiments, the addition of (+)-gossypol to the diet reduced egg production. Only laying and broiler breeder hens fed (+)-gossypol produced eggs with severe yolk discoloration (score > 4). Total feed intake was lower (P < 0.05) in laying hens fed the 400 mg/kg level of (+)-gossypol compared to laying hens fed the other dietary treatments. In contrast, broiler breeder hens consumed less of the diet supplemented with (-)-gossypol. In both experiments, tissue accumulation of (+)-gossypol was higher than (-)-gossypol, with the exception of bile and excreta. The results suggest that in hens the ingestion of (+)-gossypol has a greater effect on egg yolk discoloration than the consumption of (-)-gossypol.