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Fertility in Cheviot ewes. 2. The effect of level of pre-mating nutrition on ovulation rate and early embryo mortality in North and South Country Cheviot ewes in moderately-good condition at mating

Published online by Cambridge University Press:  02 September 2010

R. G. Gunn ,
J. M. Doney  and
W. F. Smith
R. G. Gunn
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
J. M. Doney
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
W. F. Smith
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
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Abstract

In two experiments over 2 years, 57 North Country Cheviot and 82 South Country Cheviot hill ewes were differentially group-fed indoors over a 2-month period to achieve either good or moderate body con- dition. Over 5 weeks prior to mating, ewes in good condition were brought down in condition by restricted feeding and ewes in mod- erate condition were raised in condition by a high level of feeding. The ewes were thus in moderately-good condition at mating. After mating, ewes were maintained in this condition until killed either on return to service or at 29 ± 8 days for counts of corpora lutea and viable embryos.

Ovulation rate in each breed was positively related to the level of pre-mating food intake at the condition level studied. Embryo mortality, as ova loss, was not influenced overall by the level of pre-mating food intake but loss of multiple-shed ova was greater than that of single-shed ova in ewes which had been on restricted feeding before mating. Although a greater proportion of ewes in the North Country Cheviot breed were not pregnant at slaughter, this could not be identified as a breed difference since the breeds were studied in different years.

Type
Research Article
Information
Animal Production , Volume 29 , Issue 1 , August 1979 , pp. 17 - 23
Copyright
Copyright © British Society of Animal Science 1979

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References

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