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Monthly variations in some reproductive parameters of Barki and Awassi rams throughout 1 year under subtropical conditions 1. Semen characteristics and hormonal levels

Published online by Cambridge University Press:  18 August 2016

T. A. Taha ,
E. I. Abdel-Gawad  and
M. A. Ayoub
T. A. Taha
Affiliation:
Animal Production Department, Faculty of Agriculture, Alexandria University, Alexandria, Egypt
E. I. Abdel-Gawad
Affiliation:
Animal Production Research Institute, Ministry of Agriculture, Cairo, Egypt
M. A. Ayoub
Affiliation:
Department of Animal Production, Faculty of Agricultural Sciences, UAE University, PO Box 17555, Al-Ain, United Arab Emirates
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Abstract

Fifteen sexually mature rams, five each of Barki, Awassi (I, imported from Syria) and Awassi (LB, locally born in Egypt) were used in this study. Semen was collected monthly from rams for a period of 12 months to study semen characteristics. In addition, blood samples were collected from rams during the four seasons of the year to determine serum triiodothyronine (T3) and testosterone hormones. Results showed that Barki and Awassi (I and LB) rams are continuous breeders as they show sexual desire and produce semen all the year round. However, monthly variations in semen quality were detected. Relative testes volume, ejaculate volume, sperm concentration, total sperm output, sperm motility, percentage of live sperm and serum testosterone level were higher during summer months than at other months of the year. Serum T3 was significantly higher in winter and spring than that observed in summer and autumn. In addition, percentages of dead spermatozoa were higher in winter and early spring than in autumn and summer. Furthermore, summer months showed moderate percentages of abnormal spermatozoa and spermatozoa without intact acrosomes. These results indicate that ram semen quality in the subtropics may be better during summer months than during other months of the year.

Keywords

hormonesseasonal variationsemen characterssheep
Type
Reproduction
Information
Animal Science , Volume 71 , Issue 2 , October 2000 , pp. 317 - 324
Copyright
Copyright © British Society of Animal Science 2000

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References

Aboul-Naga, A.M, Ashmawy, G. and El-Nakhla, S. 1980. Some factors affecting semen characteristics, mating and lambing performance of Rahmany rams. Egyptian Journal of Animal Production 20: 23–30.Google Scholar
Amir, D., Gacitua, H., Ron, M. and Lehrer, A. R. 1986. Seasonal variation in semen characteristics and fertility of Finn cross rams subjected to frequent ejaculation. Animal Reproduction Science 10: 75–84.CrossRefGoogle Scholar
Amir, D. and Volcani, R. 1965. Seasonal fluctuations in the sexual activity of Awassi, German Mutton Merino, Corriedale, Border Leicester and Dorset Horn rams. II. Seasonal changes in semen characteristics. Journal of Agriculture Science 64: 121–125.CrossRefGoogle Scholar
Austin, C. R. 1951. Observation on the penetration of the sperm into the mammalian egg. Australian Journal of Agricultural Research 4: 581–596.Google ScholarPubMed
Blom, E. 1983. Pathological conditions in the genital organs and in the semen as grounds for rejection of breeding bulls for import or export to or from Denmark, 1958-1982. Nordisk Veterinærmedicin 35: 105–130.Google ScholarPubMed
Bryan, J. H. and Akruk, S. R. 1977. A naphthol yellow S and Erythrosin B procedure for use in studies of the acrosome reaction of rabbit spermatozoa. Stain Technology 52: 47–51.CrossRefGoogle ScholarPubMed
El-Fouly, M.A, El-Shafie, M. M. and Kandeal, S. A. 1977. Seasonal variation in semen quality of Ossimi and Rahmani rams. Egyptian Journal of Animal Production 17: 101–116.Google Scholar
Evans, G. and Robinson, T. J. 1980. Reproductive potential and endocrinological responses of sheep kept under controlled lighting. II. Pituitary and gonadal responses of ewes and rams to a six-monthly light cycle. Animal Reproduction Science 3: 39–56.CrossRefGoogle Scholar
Follett, B. K. and Potts, C. 1990. Hypothyroidism affects reproductive refractoriness and the seasonal oestrous period in Welsh Mountain ewes. Journal of Endocrinology 127: 103–109.CrossRefGoogle ScholarPubMed
Gomes, W. R. and Joyce, M. C. 1975. Seasonal changes in serum testosterone in adult rams. Journal of Animal Science 41: 1373–1375.CrossRefGoogle ScholarPubMed
Hafez, E. S. E., Badreldin, A. L. and Darwish, Y. H. 1955. Seasonal variation in semen characteristics of sheep in the subtropics. Journal of Agriculture Science 45: 283–292.CrossRefGoogle Scholar
Juma, K. H. and Dessouky, F. 1969. Semen characteristics of Awassi rams. Journal of Agriculture Science 73: 311–314.CrossRefGoogle Scholar
Lincoln, G. A., Lincoln, C. E. and McNeilly, A. S. 1990. Seasonal cycles in the blood plasma concentration of FSH, inhibin and testosterone, and testicular size in rams of wild, feral and domesticated breeds of sheep. Journal of Reproduction and Fertility 88: 623–633.CrossRefGoogle ScholarPubMed
Moenter, S. M., Woodfill, C. J. I. and Karsch, F. J. 1991. Role of the thyroid gland in seasonal reproduction: thyroidectomy blocks seasonal suppression of reproductive neuroendocrine activity in ewes. Endocrinology 128: 1337–1344.CrossRefGoogle ScholarPubMed
Morrison, F. P. 1959. Feeds and feeding, second edition. The Morrison Pubishing Co. Inc., Clinton, IA.Google Scholar
O’Callaghan, D., Wendling, A., Karsch, F. J. and Roche, J. F. 1993. The effect of exogenous thyroxine on timing of seasonal reproductive transitions in ewe. Biology of Reproduction 49: 311–315.CrossRefGoogle Scholar
Olster, D. H. and Foster, D. L. 1988. Control of gonadotrophin secretion during the pubertal and seasonal transitions in the male sheep. Journal of Reproduction and Fertility 82: 179–191.CrossRefGoogle ScholarPubMed
Perez, R., Lopez, A., Castrillejo, A., Bielli, A., Laborde, D., Gastel, T., Tagle, R., Queirolo, D., Franco, J., Forsberg, M. and Rodriguez-Martinez, H. 1997. Reproductive seasonality of Corriedale rams under extensive rearing conditions. Acta Veterinaria Scandinavica 38: 109–117.CrossRefGoogle ScholarPubMed
Sanford, L. M., Howland, B. E. and Palmer, W. M. 1984. Seasonal changes in the endocrine responsiveness of the pituitary and testes of male sheep in relation to their patterns of gonadotropic hormone and testosterone secretion. Journal of Physiology and Pharmacology 62: 827–833.CrossRefGoogle ScholarPubMed
Sod-Moriah, V.A, Goldberg, G. M. and Bedrack, E. 1974. Intrascrotal temperature, testicular histology and fertility of heat-acclimatized rats. Journal of Reproduction and Fertility 37: 263.CrossRefGoogle Scholar
Statistical Analysis Systems Institute. 1989. SAS/STAT user’s guide, release 6·03. Statistical Analysis Systems Institute Inc., Cary, NC.Google Scholar
Webster, J. R., Moenter, S. M., Woodfill, C. J. I. and Karsch, F. J. 1991. Role of the thyroid gland in seasonal reproduction. II. Thyroxine allows a season-specific suppression of gonadotropin secretion in sheep. Endocrinology 129: 176–183.CrossRefGoogle ScholarPubMed