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Effect of various light regimes on lamb production by Rambouillet and Suffolk ewes

Published online by Cambridge University Press:  02 September 2010

J. A. Vesely  and
D. M. Bowden
J. A. Vesely
Affiliation:
Research Station, Agriculture Canada, Lethbridge, Alberta T1J 4B1, Canada
D. M. Bowden
Affiliation:
Research Station, Agriculture Canada, Lethbridge, Alberta T1J 4B1, Canada
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Abstract

Six production cycles, each of 212 days' duration, were completed with Rambouillet and Suffolk ewes. One group of each breed was maintained under natural light conditions (control) and three groups of each breed were under the influence of various light treatments applied regularly in a rhythmic fashion within each production cycle. Comparison of conception rates between production cycles, breeds, and treatments showed that only in production cycle 2 (mating in June) were the conceptions in control ewes of both breeds significantly lower than those in ewes on altered light treatments. The most meaningful result was the effect of light treatments on prolificacy. Treatment 3 (106 days with 16-h light per day and 106 days with 8-h light per day) gave significantly higher prolificacy than control and treatments 1 (106 days with 8-h light per day starting 65 days before mating) and 2 (42 days with 16-h light per day, then light reduction at 21 min/week for 160 days). Rambouillet and Suffolk control ewes produced annually 179 and 174 lambs per 100 ewes exposed to rams. Corresponding productions were 200 and 197 for treatment 1, 193 and 226 for treatment 2, and 223 and 242 for treatment 3.

Type
Research Article
Information
Animal Production , Volume 31 , Issue 2 , October 1980 , pp. 163 - 169
Copyright
Copyright © British Society of Animal Science 1980

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References

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