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Effect of previous lambing date and subsequent month of mating on reproductive performance in Mule ewes

Published online by Cambridge University Press:  18 August 2016

L. M. Mitchell ,
M. E. King ,
R. P. Aitken  and
J. M. Wallace
L. M. Mitchell
Affiliation:
Scottish Agricultural College, Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA
M. E. King
Affiliation:
Scottish Agricultural College, Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA
R. P. Aitken
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB
J. M. Wallace
Affiliation:
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB
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Abstract

The objective was to determine the effect of previous lambing date and subsequent month of mating on reproductive performance in Mule (Bluefaced Leicester × Scottish Blackface) ewes. Sixty-four ewes which had previously lambed in January (13 January (s.e. = 1 day)) and 80 ewes which had previously lambed in May (15 May (s.e. = 1 day)) were allocated equally to four mating periods (30 August to 17 September, 1 November to 19 November, 3 January to 21 January and 14 February to 4 March) in a 2 × 4 factorial design. From 20 days before and during their designated mating period, January- and May-lambing ewes were separately housed in straw-bedded pens under natural photoperiod and were given 1 kg per head per day dried grass pellets. A vasectomized ram was continuously present with each group for 17 days and was replaced by a raddled, fertility tested entire Suffolk ram at the start of the mating period. Ewes were mated at a single natural oestrus and those marked by the ram were recorded daily. Ovulation rate was measured by laparoscopy on day 6 after mating. For ewes which had previously lambed in January (16 per group), numbers by month of mating that showed oestrous behaviour, ovulated and were pregnant, respectively, were: September, 16, 15 and 12; November, 16, 15 and 14; January, 15, 15 and 10 and February, 15, 16 and 7. Mean (s.e.) ovulation rates by month of mating were 2·1 (0.16), 2·5 (0.19), 2·1 (0.09) and 2·2 (0.19) corpora lutea per ewe ovulating, and lambing rates by month of mating were 1·3 (0.25), 1·9 (0.25), 1·2 (0.24) and 0·8 (0.23) lambs per ewe to the ram. For ewes which had previously lambed in May (20 per group), numbers by month of mating that showed oestrous behaviour, ovulated and were pregnant, respectively, were: September, 13, 20 and 12; November, 20, 20 and 19; January, 20, 20 and 17 and February, 20, 20 and 13. Mean (s.e.) ovulation rates by month of mating were 2·0 (0.13), 2·3 (0.11), 2·1 (0.05) and 2·2 (0.11) corpora lutea per ewe ovulating, and lambing rates by month of mating were 1·0 (0.21), 2·1 (0.15), 1·5 (0.17) and 1·2 (0.21) lambs per ewe to the ram. Ovulation, pregnancy and lambing rates were not influenced by previous lambing date, but lambing rates were significantly (P < 0·01) reduced for ewes mated in September and February compared with November. Results demonstrate that in Mule ewes acceptable ovulation rates can be achieved throughout the period September to February but lambing rates are reduced when ewes are mated at the extremes of their natural breeding season. The main factor contributing to the reduction in lambing rates was an increase in the number of ewes failing to establish pregnancy as a consequence of ovulation without oestrous behaviour, fertilization failure and (or) total embryo loss.

Keywords

eweslambing rateovulation ratepregnancyseasonality
Type
Research Article
Information
Animal Science , Volume 69 , Issue 1 , August 1999 , pp. 217 - 222
Copyright
Copyright © British Society of Animal Science 1999

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References

Adams, N. R., Abordi, J. A., Briegel, J. R. and Sanders, M. R. 1994. Effect of diet on the clearance of estradiol-17ß in the ewe. Biology of Reproduction 51: 668–674.CrossRefGoogle Scholar
Boyd, J. S. and Ducker, M. J. 1973. A method of examining the cyclic changes occurring in the sheep ovary using endoscopy. Veterinary Record 90: 40–43.CrossRefGoogle Scholar
Downing, J. A. and Scaramuzzi, R. J. 1991. Nutrient effects on ovulation rate, ovarian function and the secretion of gonadotrophin and metabolic hormones in sheep. Journal of Reproduction and Fertility, Supplement 43: 209–227.Google Scholar
Haresign, W. 1981. The influence of nutrition on reproduction in the ewe. 1. Effects on ovulation rate, follicle development and luteinizing hormone release. Animal Production 32: 197–202.Google Scholar
Karsh, F. J., Bittman, E. L., Foster, D. L., Goodman, R. L., Legan, S. J. and Robinson, J. E. 1984. Neuroendocrine basis of seasonal reproduction. Recent Progress in Hormone Research 40: 185–231.Google Scholar
Knight, T. W. 1983. Ram induced stimulation of ovarian and oestrous activity in anoestrous ewes — a review. Proceedings of the New Zealand Society of Animal Production 43: 7–11.Google Scholar
Lindsay, D. R., Cognie, Y., Pelletier, J. and Signoret, J. P. 1975. Influence of the presence of rams on the timing of ovulation and discharge of LH in ewes. Physiology and Behaviour 15: 423–426.CrossRefGoogle ScholarPubMed
Martin, G. B., Oldham, C. M., Cognie, Y. and Pearce, D. T. 1984. The physiological responses of anovulatory ewes to the introduction of rams — a review. Livestock Production Science 15: 219–247.Google Scholar
Minton, J. E., Coppinger, T. R., Spaeth, C. W. and Martin, L. C. 1991. Poor reproductive response of anoestrous Suffolk ewes to ram exposure is not due to failure to secrete luteinizing hormone acutely. Journal of Animal Science 69: 3314–3320.Google Scholar
Mitchell, L. M., King, M. E., Aitken, R. P. and Wallace, J. M. 1997. Influence of lambing date on subsequent ovarian cyclicity and ovulation rate in ewes. Animal Science 65: 75–81.CrossRefGoogle Scholar
Mitchell, L. M., King, M. E., Aitken, R. P., Gebbie, F. E. and Wallace, J. M. 1999. Ovulation, fertilisation and lambing rates, and peripheral progesterone concentrations, in ewes inseminated at a natural oestrus during November or February. Journal of Reproduction and Fertility 115:133–140.CrossRefGoogle ScholarPubMed
Nancarrow, C. D. 1994. Embryonic mortality in the ewe and doe. In Embryonic mortality in domestic species (ed. Zavy, M. T. and Geisert, R. D.). CRC Press, Salem, USA.Google Scholar
Parr, R. A. 1992. Nutrition-progesterone interactions during early pregnancy in sheep. Reproduction, Fertility and Development 4: 297–300.Google Scholar
Pollott, G. 1998. Sheep breeds and breeding in Britain 1996-97. In Sheep yearbook 1998, pp. 37–53. Meat and Livestock Commission, Milton Keynes, UK.Google Scholar
Robinson, J. E., Radford, H. M. and Karsh, F. J. 1985. Seasonal changes in pulsatile luteinizing hormone (LH) secretion in the ewe: relationship of frequency of LH pulses to day length and response to estradiol negative feedback. Biology of Reproduction 33: 324–334.Google ScholarPubMed
Russel, A. J. F., Doney, J. M. and Gunn, R. B. 1969. Subjective assessment of body fat in live sheep. Journal of Agricultural Science, Cambridge 72: 451–454.CrossRefGoogle Scholar
Scaramuzzi, R. J. and Radford, H. N. 1983. Factors regulating ovulation rate in the ewe. Journal of Reproduction and Fertility 69: 353–367.CrossRefGoogle ScholarPubMed
Vipond, J. E. V. 1997. May lambing: production targets. Technical note T429, Scottish Agricultural College, Edinburgh, UK.Google Scholar
Wallace, J. M., Aitken, R. P. and Cheyne, M. A. 1994. Effect of post-ovulation nutritional status in ewes on early conceptus survival and growth in vivo and luteotrophic protein secretion in vitro . Reproduction, Fertility and Development 6: 253–259 Google ScholarPubMed
Zarco, L., Rodriguez, E. F., Angulo, M. R. B. and Valencia, J. 1995. Female to female stimulation of ovarian activity in the ewe. Animal Reproduction Science 39: 251–258.Google Scholar