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A twice-yearly lambing system, using Finnish Landrace×Dorset Horn ewes

Published online by Cambridge University Press:  02 September 2010

J. G. S. Duncan  and
W. J. M. Black
J. G. S. Duncan
Affiliation:
School of Agriculture, University of Edinburgh, West Mains Road, Edinburgh EH9 3JG
W. J. M. Black
Affiliation:
School of Agriculture, University of Edinburgh, West Mains Road, Edinburgh EH9 3JG
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Abstract

Between July 1971 and June 1973 a flock of between 60 and 100 Finn-Dorset ewes were mated at 6-monthly intervals in July and January each year following oestrus synchronization. The conception rates at each mating were:

July 1971—51 from 67 mated (76%) using hand-mating with a follow-up of paddock mating (1 ram: 9 ewes);

January 1972—6 from 63 (10%) using artificial insemination only; July 1972—98 from 102 (97%) using paddock mating (1 ram: 10 ewes);

January 1973—28 from 80 (35%) using pen mating (1 ram: 10 ewes).

Satisfactory breeding performance was achieved at the July matings in both years, resulting in production of lambs for the early spring market. The very poor results of the January 1972 mating were associated with the problems of artificial insemination in the recently lambed ewe. The conception rate achieved at the January 1973 mating provided a clearer indication of the difficulty of achieving satisfactory remating within 40 days post partum, which is necessary to achieve a true 6-monthly lambing pattern.

The early initiation of the synchronization technique (7 days post partum) followed by mating only at the second oestrus in January 1973 appeared to offer some encouragement. While a number (48) of ewes were induced to lamb at least once at 6-monthly intervals, only one ewe lambed four times in 24 months.

Type
Research Article
Information
Animal Production , Volume 26 , Issue 3 , June 1978 , pp. 301 - 308
Copyright
Copyright © British Society of Animal Science 1978

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References

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