The effects of dietary selenium on growth and selected reproductive parameters in young boars
| Autor: | J. P. Hitchcock, S. A. Kincaid, M. C. Henson, H. G. Kattesh |
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| Rok vydání: | 1983 |
| Předmět: | |
| Zdroj: | Animal Science. 37:401-407 |
| ISSN: | 1748-748X 1357-7298 |
| Popis: | Thirty-three crossbred boars, 47 to 58 days of age, were randomly allocated to receive maize-soya bean meal diets containing 0·05, 0·15 or 0·30 mg selenium per kg. Body weights, testicular widths, and blood samples from vena cava puncture were taken at regular intervals. Libido was subjectively scored upon exposure to ovariectomized-oestrogenized gilts. Seven animals from each group were slaughtered at 9 months of age and selected reproductive structures were retrieved. Analysis of the relationships among body weight, libido and plasma testosterone levels indicated that differences (P < 0·01) existed between treatments, as analyzed over time, but that the overall treatment effect was not significant. Testicular widths were also found to be different (P < 0·05) over time. Values for all four criteria as measured over time were greater for boars fed 0·05 mg selenium per kg than for those fed 0·15 which were in turn greater than those fed 0·30. Post-mortem examination showed no treatment differences (1) in testis weights; (2) spermatozoan concentrations within the capita, corporea or caudae segments of the epididymis and (3) spermatozoan morphology examined within the caudae epididymis. Also testis lengths, weights, circumferences and spermatozoan concentrations were not significantly different between treatments. These results suggest that boars fed selenium at 0·15 or 0·30 mg/kg may exhibit some signs of retarded sexual development for a short period preceding the onset of sexual maturity |
| Databáze: | OpenAIRE |
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