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Effects of crossbreeding and certain environmental factors on multiple births, wool production and growth in sheep

Published online by Cambridge University Press:  02 September 2010

M. H. Fahmy  and
C. S. Bernard
M. H. Fahmy
Affiliation:
Canada Department of Agriculture, Research Station, Lennoxville, Quebec, Canada
C. S. Bernard
Affiliation:
Canada Department of Agriculture, Research Station, Lennoxville, Quebec, Canada
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Summary

Multiple birth percentage and wool production were studied on 338 ewes (907 lambing and 873 shearing records) representing two purebreds, Oxford (O) and Suffolk (S), and four crossbreds, O × S, S × O, Cheviot (C) × O and C × S mated to purebred and crossbred rams during 9 years. Oxford ewes had 24–32% (P<0·01) fewer multiple births than ewes of the other groups, while little difference between S and the crossbreds was observed. The heterosis of the OS and SO groups was 14·6 ± 4·1%. Multiple births tended to increase 0·8% for each kg increase in body weight of the dam (r = 0·13). The repeatability estimate for multiple births was 0·24. Fleece weight was significantly affected by age and by breed group, with OS and SO crosses producing 17% more wool than their parental breeds. The repeatability of fleece weight was estimated at 0·52 ± 0·15. Fleece weight was significantly correlated with multiple birth percentage (0·09) and body weight (0·32).

Suffolk ewes averaged 9·5 kg heavier than O ewes throughout their reproductive life. The two reciprocal crosses were heavier than both parental breeds. Suffolk ewes reached their maximum body weight at 4 years of age while Oxfords continued to gain weight up to 6 years.

Type
Research Article
Information
Animal Production , Volume 16 , Issue 2 , April 1973 , pp. 147 - 155
Copyright
Copyright © British Society of Animal Science 1973

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