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The influence of seasonal variation on fertility and early body growth in sheep

Published online by Cambridge University Press:  02 September 2010

R. B. Land
Affiliation:
A.R.C. Animal Breeding Research Organisation, West Mains Road, Edinburgh 9
A. G. Dickinson
Affiliation:
A.R.C. Animal Breeding Research Organisation, West Mains Road, Edinburgh 9
J. L. Read
Affiliation:
A.R.C. Animal Breeding Research Organisation, West Mains Road, Edinburgh 9
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Summary

The effect of the time of mating on ewe fertility and subsequent lamb growth was examined in Clun sheep in Scotland. The flock of 249 females was divided into six mating groups, the first was put to a fertile ram on 12 October 1962, the remainder being added at two weekly intervals.

There was a marked decline in the average number of lambs born per female lambing as the time of mating moved from October to December (b = −0·007 per female per day). Other components of fertility were not affected.

The mean birth weight was slightly greater in the later mating groups; however, by the time the lambs were 9 weeks of age, the trend was reversed, the regression of 9-week weight on day of mating being −0·063 lb per day.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1969

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References

REFERENCES

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