The effect of gossypol in cottonseed meal on performance and on hematological and semen traits in postpubertal Brahman bulls.
The effects of a cottonseed meal diet containing high levels of free gossypol on hematological traits, including erythrocyte osmotic fragility and semen characteristics, were examined during an 11-week period. Eight Brahman bulls were randomly assigned to 1 of 2 groups. The control group (n=4) was fed a mixture of soybean meal and corn. The treated group (n=4) was fed a mixture of cottonseed meal and corn. Both groups were allowed hay free choice. The treated group consumed 8.2 g of free gossypol per bull per day. The percentage of normal spermatozoa was lower (P<0.01) in the treated than in the control group from Week 5 (49+/-9.8 vs 83+/-3.2%), which was primarily influenced by changes in mid piece morphology in the treated bulls. Erythrocyte osmotic fragility was higher (P<0.001) in the treated than in the control group over the entire study period, although group values diverged more acutely from Week 7 of treatment. Sperm motility was lower (P=0.04) in treated bulls than in control bulls at Week 9 (52+/-9.8 vs 82+/-6.2%). These data suggest that concurrent discernable changes in bull erythrocyte osmotic fragility and in semen characteristics can occur following commencement of a diet containing 8.2g of free gossypol per day.
Risco
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Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA.
Chenoweth
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PJ
Larsen
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Velez
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Shaw
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Tran
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Chase
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