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The effect of level of nutrition prior to mating on the reproductive performance of ewes of two welsh breeds in different levels of body condition

Published online by Cambridge University Press:  02 September 2010

R. G. Gunn ,
T. J. Maxwell ,
D. A. Sim ,
J. R. Jones  and
M. E. James
R. G. Gunn
Affiliation:
Macaulay Land Use Research Institute, Pentlandfield, Roslin, Midlothian EH25 9RF
T. J. Maxwell
Affiliation:
Macaulay Land Use Research Institute, Pentlandfield, Roslin, Midlothian EH25 9RF
D. A. Sim
Affiliation:
Macaulay Land Use Research Institute, Pentlandfield, Roslin, Midlothian EH25 9RF
J. R. Jones
Affiliation:
AFRC Institute for Grassland and Animal Production, Welsh Plant Breeding Station, Bronydd Mawr, Trecastle, Brecon, Powys LD3 8RD
M. E. James
Affiliation:
AFRC Institute for Grassland and Animal Production, Welsh Plant Breeding Station, Bronydd Mawr, Trecastle, Brecon, Powys LD3 8RD
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Abstract

The effects of high-low (HL) and low-high (LH) patterns of nutrition during the 5 weeks prior to a synchronized mating were studied on the reproductive performance of 115 Welsh Mountain and 114 Brecknock Cheviot ewes in a range of body condition at the start of treatment. For 2 months prior to treatment imposition, ewes were grazed in a systematic way at different stocking rates on different sward heights to obtain a range of body condition scores. Target score groupings were 2·00 to 2·25, 2·50 to 2·75 and 3·00 to 3·25 and although scores of 1·50 to 3·25 were obtained, most lay in the 2·00 to 2·75 range. Two treatment groups, balanced for live weight and body condition score, received high and low levels of nutrition for 16 days from mid October, achieved, respectively, by a low stocking rate on a sward with a high surface height plus ad libitum concentrate and a high stocking rate on a sward with a low surface height plus 200 g hay per head per day. Treatments were then reversed for the 17 days prior to mating. Live-weight and body condition-score changes were recorded and reproductive performance at first mating was measured from counts of corpora lutea and viable embryos at slaughter either at return to service or at 4 weeks after first mating. There were no differences due to nutritional pattern in live weight or body condition score at mating. The LH treatment significantly increased the rates of ovulation, conception, multiple ova survival and potential lambing per ewe pregnant and per ewe mated in the Welsh Mountain breed but significantly increased only the rates of ovulation and potential lambing per ewe pregnant in the Brecknock Cheviot breed compared with the HL treatment. The relatively poorer response in the latter breed was partially due to a lower ovulation rate potential coupled with non-significantly lower rates of conception and survival of single-shed ova associated with the LH treatment. Much of this relatively poorer reproductive performance in the Brecknock Cheviot breed was in ewes with body condition scores 3= 2·75. Reproductive performance increased with increasing body condition at the start of treatment over the range of scores =≤ 2·25 to 2·50 in both breeds and, while continuing to improve in scores above 2·50 in the Welsh Mountain breed, in the Brecknock Cheviot breed it started to decline. Ewes with a body condition score of 2·50 in both breeds showed the greatest response in potential lambing rate to the LH treatment.

Keywords

body conditionnutritionreproductive performancesheep
Type
Research Article
Information
Animal Production , Volume 52 , Issue 1 , February 1991 , pp. 157 - 163
Copyright
Copyright © British Society of Animal Science 1991

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References

REFERENCES

Gumming, I. A. 1972. The effect of increasing and decreasing live weight on ovulation and embryonic survival in the Border Leicester × Merino ewe. Proceedings of the Australian Society of Animal Production 9: 192–198.Google Scholar
Gunn, R. G. and Doney, J. M. 1975. The interaction of nutrition and body condition at mating on ovulation rate and early embryo mortality in Scottish Blackface ewes. Journal of Agricultural Science, Cambridge 85: 465–470.CrossRefGoogle Scholar
Gunn, R. G. and Doney, J. M. 1979. Fertility in Cheviot ewes. 1. The effect of body condition at mating on ovulation rate and early embryo mortality in North and South Country Cheviot ewes. Animal Production 29: 11–16.Google Scholar
Gunn, R. G., Doney, J. M. and Russel, A. J. F. 1969. Fertility in Scottish Blackface ewes as influenced by nutrition and body condition at mating. Journal of Agricultural Science, Cambridge 73: 289–294.CrossRefGoogle Scholar
Gunn, R. G., Doney, J. M. and Smith, W. F. 1979. 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. Animal Production 29: 17–23.Google Scholar
Gunn, R. G., Doney, J. M. and Smith, W. F. 1984a. The effect of different durations and times of high-level feeding prior to mating on the reproductive performance of Scottish Blackface ewes. Animal Production 39: 99–105.Google Scholar
Gunn, R. G., Doney, J. M. and Smith, W. F. 1984b. The effect of level of pre-mating nutrition on ovulation rate in Scottish Blackface ewes in different body conditions at mating. Animal Production 39: 235–239.Google Scholar
Gunn, R. G., Smith, W. F., Senior, A. J., Barthram, E., Sim, D. A. and Hunter, E. A. 1990. Pre-mating herbage intake and the reproductive performance of North Country Cheviot ewes in different levels of body condition. Animal Production 52: 149–156.Google Scholar
Lawes Agricultural Trust. 1987. Genstat V Reference Manual. Clovendon Press, London.Google Scholar
Milne, J. A., Sibbald, A. M., Lamb, C. S., McCormack, H. A., Mayes, R. W. and Lees, J. A. 1986. The herbage intake of ewes grazing perennial ryegrass swards and when given supplements during lactation and in the autumn. In Grazing (ed. Frame, J.), British Grassland Society Occasional Symposium No. 19, pp. 124–128.Google Scholar
Weiner, G. 1973. Breeding for increased productivity. Veterinary Record 92: 609–613.CrossRefGoogle Scholar