Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-27T13:59:51.676Z Has data issue: false hasContentIssue false
  • English
  • Français

Resistance to cold stress in sheep shorn by cover comb or standard comb

Published online by Cambridge University Press:  02 September 2010

N. Dabiri ,
C. W. Holmes ,
S. N. McCutcheon ,
W. J. Parker  and
S. T. Morris
N. Dabiri
Affiliation:
Department of Animal Science, Massey University, Palmerston North, New Zealand
C. W. Holmes
Affiliation:
Department of Animal Science, Massey University, Palmerston North, New Zealand
S. N. McCutcheon
Affiliation:
Department of Animal Science, Massey University, Palmerston North, New Zealand
W. J. Parker
Affiliation:
Department of Agricultural and Horticultural Systems Management, Massey University, Palmerston North, New Zealand
S. T. Morris
Affiliation:
Department of Animal Science, Massey University, Palmerston North, New Zealand
Get access

Abstract

The cover comb has been developed in New Zealand as a means of increasing residual fleece depth after shearing and so increasing the resistance of shorn sheep to cold stress.

The effects of shearing by cover comb and standard comb were studied over 2 days pre-shearing and 10 days post-shearing in eight pairs of non-pregnant, non-lactating 2-year-old ewes. Animals were housed and given a maintenance level of chaffed lucerne hay. One member of each pair was shorn with a cover comb, the other with a standard comb. Each pair was exposed to ‘cold plus wind’ (7°C ambient temperature, 7 km/h air movement) followed by ‘cold plus wind plus rain’ (10°C ambient temperature, 7km/h air movement, wetting at a rate equivalent to 25 mm/h rain from overhead sprinklers) in a calorimetry chamber on days S –3, S –2, SO (day of shearing), S2, S6 and S10. Heat production immediately after shearing (SO) was proportionately 0·22 greater in ewes shorn by the standard comb under conditions of ‘cold plus wind’ and 0·38 greater under conditions of ‘cold plus wind plus rain’ than in their cover comb-shorn cohorts. Circulating concentrations of non-esterifiedfatty acids were substantially elevated on the day of shearing and 2 days thereafter in ewes shorn by the standard comb, indicating increased rates of body fat mobilization to support heat production in these ewes compared with those shorn by the cover comb. This was reflected in a 1·4 kg weight loss in the standard comb-shorn ewes compared with a 0·4 kg live-weight gain in the cover comb-shorn group over the 10 days of the experiment. It was concluded that use of a cover comb will significantly reduce the risk of death from hypothermia in sheep shorn during winter and spring, and should facilitate an increase in the productivity of animals by allowing a greater proportion of food energy to be used for productive purposes.

Keywords

cold resistanceewesfleeceheat productionshearing
Type
Research Article
Information
Animal Science , Volume 60 , Issue 3 , June 1995 , pp. 451 - 456
Copyright
Copyright © British Society of Animal Science 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agricultural Research Council. 1980. The nutrient requirements of ruminant livestock. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Blaxter, K. L. 1977. Environmental factors and their influence on the nutrition of farm livestock. In Nutrition and the climatic environment (ed. Haresign, W., Swan, H. and Lewis, D.), pp. 1–15. Butterworths, London.Google Scholar
Brody, S. 1945. Bioenergetics and growth. Reinhold, New York.Google Scholar
Dabiri, N., Morris, S. T., Parker, W. J., McCutcheon, S. N. and Wickham, G. A. 1995. Productivity and cold resistance in ewes pre-lamb shorn by standard or cover comb. Australian Journal of Agricultural Research In press.Google Scholar
Holmes, C. W. 1973. The energy and protein metabolism of pigs growing at a high ambient temperature. Animal Production 16: 117–133.Google Scholar
Holmes, C. W., Kamil, K. A., Parker, W. J., Mackenzie, D. D. S., Purchas, G. and Kidd, R. 1992. Effects of shearing method on the physiology and productivity of sheep. Proceedings of the New Zealand Society of Animal Production 52: 199–202.Google Scholar
Holmes, C. W. and McLean, N. A. 1975. Effects of air temperature and air movement on the heat produced by young Friesian and Jersey calves, with some measurements of the effects of artificial rain. New Zealand Journal of Agricultural Research 18: 277–284.CrossRefGoogle Scholar
McLean, J. A. 1972. On the calculation of heat production from open-circuit calorimetric measurements. Britisli Journal of Nutrition 27: 597–600.CrossRefGoogle ScholarPubMed
Michel, A., McCutcheon, S. N., Mackenzie, D. D. S., Tait, R. M. and Wickham, B. W. 1991. Metabolic responses to exogenous bovine somatotropin in Friesian cows of low or high genetic merit. Domestic Animal Endocrinology 8: 293–306.CrossRefGoogle ScholarPubMed