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The effects of breed, birthcoat and body weight on the cold resistance of newborn lambs

Published online by Cambridge University Press:  02 September 2010

J. Slee
J. Slee
Affiliation:
ARC Animal Breeding Research Organisation, West Mains Road, Edinburgh EH9 3JQ
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Abstract

1. Twenty-two Scottish Blackface, 51 Welsh Mountain and 22 Tasmanian Merino lambs aged between 6 and 75 h were tested for resistance to body cooling in a climate chamber. Blackface lambs had long birthcoats, Merinos were short-coated. Welsh lambs were from two strains with long (L) and short (S) types of birthcoat. Some lambs were clipped before cold exposure.

2. Clipping reduced cold resistance in Welsh (S) and (L) lambs by factors of 3 and 13 respectively.

3. Undipped lambs showed significant breed differences, Welsh (L) and Blackfaces having the greatest cold resistance and Merinos the least. Long-coated lambs (Blackface and Welsh (L)) were on average six times more cold resistant than the average of Welsh (S) and Merino lambs; and Welsh (L) lambs were four times more resistant than the Welsh (S) type. Birth weight and age did not significantly influence cold resistance.

4. In clipped lambs there was a significant positive linear regression between cold resistance and birth weight. Breed differences in cold resistance were still significant if no adjustment was made for the effect of breed differences in birth weight.

5. Cold resistance was strongly influenced by breed differences in birthcoat morphology and probably by other physiological factors partly attributable to the different genetic backgrounds associated with birthcoat type. The breed differences in cold resistance were generally consistent with field data on mortality and body temperature regulation of lambs in severe weather, suggesting that climate chamber tests might be used to evaluate potential viability in the field.

Type
Research Article
Information
Animal Production , Volume 27 , Issue 1 , August 1978 , pp. 43 - 49
Copyright
Copyright © British Society of Animal Science 1978

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References

REFERENCES

Alexander, G. 1961. Temperature regulation in the new-born lamb. III. Effect of environmental temperature on metabolic rate, body temperatures and respiratory quotient. Aust. J. agric. Res. 12: 1152–1174.CrossRefGoogle Scholar
Alexander, G. 1962. Temperature regulation in the new-born lamb. V. Summit metabolism. Aust. J. agric. Res. 13: 100–121.CrossRefGoogle Scholar
Alexander, G., Bell, A. W. and Williams, D. 1970. Metabolic response of lambs to cold. Effects of prolonged treatment with thyroxine and of acclimation to low temperatures. Biol. Neonate 15: 198–210.CrossRefGoogle ScholarPubMed
Alexander, G. and Williams, D. 1968. Shivering and non-shivering thermogenesis during summit metabolism in young lambs. J. Physiol., Lond. 198: 251–276.CrossRefGoogle ScholarPubMed
Mercer, J. B. 1974. Thermoregulation in the new-born lamb. Ph.D. Thesis, Trinity College, Dublin.Google Scholar
O'Neill, R. and Wetherill, G. B. 1971. The present state of multiple comparison methods. Jl R. statist. Soc. 33: 218–240.Google Scholar
Purser, A. F. 1967a. Selection experiments with hill sheep. Proc. 9th int. Congr. Anim. Prod. Edinburgh, 1966, pp. 32–38.Google Scholar
Purser, A. F. 1967b. Is lamb birthcoat type related to hardiness? Rep. Anim. Breed. Res. Org. Her Majesty's Stationery Office, London.Google Scholar
Purser, A. F. and Karam, H. A. 1967. Lamb survival, growth and fleece production in relation to birthcoat type among Welsh Mountain sheep. Anim. Prod. 9: 75–85.Google Scholar
Slee, J. 1974. The retention of cold acclimatization in sheep. Anim. Prod. 19: 201–210.Google Scholar
Sykes, A. R., Griffiths, R. G. and Slee, J. 1976. Influence of breed, birth weight and weather on the body temperature of new-born lambs. Anim. Prod. 22: 395–402.Google Scholar
Wiener, G. and Hayter, Susan. 1975. Maternal performance in sheep as affected by breed, crossbreeding and other factors. Anim. Prod. 20: 19–30.Google Scholar