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Relationships between body weight and scrotal characteristics, and between environmental effects and fertility in Ethiopian Horro rams

Published online by Cambridge University Press:  27 March 2009

Yohannes Gojjam ,
Solomon Gizaw ,
Solomon Abegaz  and
C. J. Thwaites
Yohannes Gojjam
Affiliation:
Bako Research Centre, Institute of Agricultural Research, PO Box 2003, Addis Ababa, Ethiopia
Solomon Gizaw
Affiliation:
Bako Research Centre, Institute of Agricultural Research, PO Box 2003, Addis Ababa, Ethiopia
Solomon Abegaz
Affiliation:
Bako Research Centre, Institute of Agricultural Research, PO Box 2003, Addis Ababa, Ethiopia
C. J. Thwaites
Affiliation:
Bako Research Centre, Institute of Agricultural Research, PO Box 2003, Addis Ababa, Ethiopia
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Summary

The relationships between body weight, scrotal characteristics and environmental effects (year, birth type and age) and fertility were studied in a total of 254 Horro rams. Fertility varied between years (P < 0·01), but not with body weight at mating within the range (30–55 kg) observed, nor with type of birth (both P > 0·05).

Testicular diameter and circumference were strongly correlated to body weight (r = 0·95 and 0·89 respectively; both P < 0·001), but weight of testes only weakly so (r = 0–28; NS). Scrotal circumference was more highly correlated to body weight in ram lambs (r = 0–85; P < 0–001) than in adults (r = 0·51; p = 0·06).

It is concluded that adequate levels of fertility (82 ± 1·3%) are expressed by 30 kg Horro rams, and that when feed supplies are limited there are no benefits to be gained from maintaining rams of this breed at higher weights.

Type
Animals
Information
The Journal of Agricultural Science , Volume 124 , Issue 2 , April 1995 , pp. 297 - 299
Copyright
Copyright © Cambridge University Press 1995

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References

Dýrmundsson, Ó. R. (1978). A note on sexual development of Icelandic rams. Animal Production 26, 335–338.Google Scholar
Fraser, A. F. (1968). Reproductive Behaviour in Ungulates. London: Academic Press.Google Scholar
Galal, E. S. E. (1983). Sheep germ plasm in Ethiopia. Animal Genetic Resources Information 1, 4–12.Google Scholar
Galal, E. S. E., El-Gamal, A. A., Aboul-Naga, A. & El-Fouly, M. A. (1978). Male reproductive characteristics of Merino and Ossimi sheep and their crosses. Animal Production 27, 261–267.Google Scholar
Harvey, W. R. (1990). User's Guide for Mixed Model Least-Squares and Maximum Likelihood Computer Program PC- 2. Columbus: Ohio State University.Google Scholar
Mukasa-Mugerwa, E. & Ezaz, Z. (1992). Relationship of testicular growth and size to age, body weight and onset of puberty in Menz ram lambs. Theriogenology 38, 979–988.CrossRefGoogle ScholarPubMed
Oldham, C. M., Adams, N. R., Gherardi, P. B., Lindsay, D. R. & Mackintosh, J. B. (1978). The influence of level of feed intake on sperm-producing capacity of testicular tissue in the ram. Australian Journal of Agricultural Research 29, 173–179.CrossRefGoogle Scholar
Raadsma, H. W. & Edey, T. N. (1985). Mating performance of paddock-mated rams. I. Changes in mating performance, ejaculate characteristics and testicular size during the joining period. Animal Reproduction Science 8, 79–99.CrossRefGoogle Scholar
Simpson, H. & Edey, T. N. (1979). Changes in physical condition and ejaculate characteristics in paddock-mated rams. Australian Veterinary Journal 55, 225–228.CrossRefGoogle ScholarPubMed
Terrill, C. E. (1962). Reproduction in sheep. In Reproduction in Farm Animals (Ed. Hafez, E. S. E.), pp. 273–296. Philadelphia: Lea & Febiger.Google Scholar
Zinesh, Sileshi & Seyoum, Bediye (1989). Utilization of feed resources and feeding systems in the central zone of Ethiopia. In National Livestock Improvement Conference, Addis Ababa. No.3, pp. 129–133.Google Scholar