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A note on the effect of interbreeding among backcrosses of sheep breeds

Published online by Cambridge University Press:  02 September 2010

A. Aboul-Naga  and
E. S. E. Galal
A. Aboul-Naga
Affiliation:
Ministry of Agriculture and Ain Shams University, Cairo, UAR
E. S. E. Galal
Affiliation:
Ministry of Agriculture and Ain Shams University, Cairo, UAR
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Summary

The records of 873 lambs from Ossimi and Barki backcrosses to Merino, and the first and second generations of their interbreeding were analysed. The traits included were: birth, weaning and yearling weights, first fleece weight and lamb mortality.

The interbred groups had about 10–15% lower body and fleece weights than their backcross parents, and almost double the lamb mortality. Differences between the interbred groups and the back-cross parents were predicted from the performance of purebreds, first crosses and backcrosses. There was good agreement between prediction and observation for birth and fleece weights, fair agreement for weaning and yearling weights, but lamb mortality increased more than expected.

Maternal heterosis seems to be more important than individual heterosis for body weight, and the reverse for fleece weight. Both components are large for lamb viability.

Type
Research Article
Information
Animal Production , Volume 16 , Issue 1 , February 1973 , pp. 87 - 90
Copyright
Copyright © British Society of Animal Science 1973

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References

REFERENCES

Aboul-Naga, A., Eltawil, E., Galal, E. S. E., Labban, F. and Khishin, S. 1972. The effects of crossing Merino with Ossimi and Barki sheep on some productive traits. J. agric. Sci., Camb. 78: 275–280.CrossRefGoogle Scholar
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Galal, E. S. E., Aboul-Naga, A., Eltawil, E. and Khishin, S. 1972. Estimates of combining abilities and maternal influence in crosses between Merino, Ossimi and Barki sheep. Anim. Prod. 15: 47–52.Google Scholar
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