Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-05T06:17:51.464Z Has data issue: false hasContentIssue false

Effects of body condition and environmental stress on ovulation rate, embryo survival, and associated plasma follicle stimulating hormone, luteinizing hormone, prolactin and progesterone profiles in Scottish Blackface ewes

Published online by Cambridge University Press:  02 September 2010

S. M. Rhind
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
J. M. Doney
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
R. G. Gunn
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
I. D. Leslie
Affiliation:
Hill Farming Research Organisation, Bush Estate, Penicuik, Midlothian EH26 0PY
Get access

Abstract

In a 2 × 2 factorial experiment, half of each of two groups of ewes in high (20 ewes) or low body condition (20 ewes) were subjected to procedures designed to simulate normal management and climatic stresses, and the effects of these treatments on ovulation rate, embryo survival and endocrine status were investigated.

The mean ovulation rate of ewes in the high condition group was significantly higher than that of ewes in the low condition group (1·8 v. 11) (P < 0·001). Embryo survival rates were unaffected. Neither ovulation rate nor embryo survival were affected by stressful treatments.

Circulating follicle stimulating hormone, luteinizing hormone and prolactin levels were recorded in the peri-ovulatory period. Mean circulating follicle stimulating hormone levels were similar in three of the treatment groups but were generally lower in ewes in the low condition/stressed group. This difference was significant in some of the sampling periods. Neither basal levels of luteinizing hormone nor the size of the pre-ovulatory luteinizing hormone surge were significantly affected by level of body condition or stress but the surge began earlier in ewes in the low condition groups. The difference in timing was not, however, related to ovulation rate. Circulating prolactin levels were consistently and often significantly lower in ewes in poor condition (P < 0·05). Levels were not significantly affected by stress.

While ovulation rate was affected by body condition, the recorded progesterone profiles during the first 2 weeks after mating suggest that luteal function was not affected by any of the treatments applied.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1984

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

REFERENCES

Baird, D. T. 1978. Pulsatile secretion of LH and ovarian estradiol during the follicular phase of the sheep estrous cycle. Biol. Reprod. 18: 359364.CrossRefGoogle ScholarPubMed
Baird, D. T. and McNeilly, A. S. 1981. Gonadotrophic control of follicular development and function during the oestrous cycle of the ewe. J. Reprod. & Fert., Suppl. 30, pp. 119133.Google Scholar
Baird, D. T., Swanston, I. A. and McNeilly, A. S. 1981. Relationship between LH, FSH and prolactin concentration and the secretion of androgens and estrogens by the preovulatory follicle in the ewe. Biol. Reprod. 24: 10131025.CrossRefGoogle ScholarPubMed
Baker, T. B. and Hunter, R. H. F. 1978. Interrelationships between the oocyte and somatic cells within the Graafian follicle of mammals. Annls Biol. anim. Biochim. Biophys. 18: 419426.CrossRefGoogle Scholar
Doney, J. M., Gunn, R. G., Smith, W. F. and Carr, W. R. 1976a. Effects of pre-mating environmental stress, ACTH, cortisone acetate or metyrapone on oestrus and ovulation in sheep. J. agric. Sci., Camb. 87: 127132.CrossRefGoogle Scholar
Doney, J. M., Smith, W. F. and Gunn, R. G. 1976b. Effects of post-mating environmental stress or administration of ACTH on early embryonic loss in sheep. J. agric. Sci., Camb. 87: 133136.CrossRefGoogle Scholar
Easdon, M. 1981. The effect of undernutrition on some hormones and metabolites in the blood of intact and ovariectomised beef cows. Ph.D. Thesis, Univ. Aberd.Google Scholar
Findlay, J. K. and Cumming, I. A. 1976. FSH in the ewe: effects of season, live weight and plane of nutrition on plasma FSH and ovulation rate. Biol. Reprod. 15: 335342.CrossRefGoogle ScholarPubMed
Forbes, J. M., Driver, P. M., El-Shahat, A. A., Boaz, T. G. and Scanes, C. G. 1975. The effect of daylength and level of feeding on serum prolactin in growing lambs. J. Endocr. 64: 549554.CrossRefGoogle ScholarPubMed
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. J. agric. Sci., Camb. 85: 465470.CrossRefGoogle Scholar
Haresign, W. 1981. The influence of nutrition on reproduction in the ewe. 1. Effects on ovulation rate. follicle development and luteinizing hormone release. Anim. Prod. 32: 197202.Google Scholar
Kann, G., Martinet, J. and Schirar, A. 1976. Impairment of luteinising-hormone release following oestrogen administration to hyperprolactinaemic ewes. Nature, Lond. 264: 465466.CrossRefGoogle ScholarPubMed
Louw, B. P., Lishman, A. W. and Botha, W. A. 1974. Stress-induced release of prolactin in cycling and anoestrous ewes and in wethers. S. Afr. J. Anim. Sci. 14: 131135.Google Scholar
Louw, B. P., Lishman, A. W., Botha, W. A. and Baumgartner, J. P. 1974. Failure to demonstrate role for the acute release of prolactin at oestrus in the ewe. J. Reprod. & Fert. 40: 455458.CrossRefGoogle ScholarPubMed
McNeilly, A. S. and Andrews, P. 1974. Purification and characterisation of caprine prolactin. J. Endocr. 60: 359367.CrossRefGoogle ScholarPubMed
McNeilly, A. S., Glasier, Anna Jonassen Julie and HOWIE, P. W. 1982. Evidence for direct inhibition of ovarian function by prolactin. J. Reprod. & Fert. 65: 559569.CrossRefGoogle ScholarPubMed
McNeilly, J. R., McNeilly, A. S., Walton, J. S. and Cunningham, F. J. 1976. Development and application of a heterologous radioimmunoassay for ovine folliclestimulating hormone. J. Endocr. 70: 6979.CrossRefGoogle Scholar
Martensz, N. D., Baird, D. T., Scaramuzzi, R. and Van Look, P. F. A. 1976. Androstenedione and the control of luteinizing hormone in the ewe during anoestrus. J. Endocr. 69: 227237.CrossRefGoogle ScholarPubMed
Russel, A. J. F., Doney, J. M. and Gunn, R. G. 1969. Subjective assessment of body fat in live sheep. J. agric. Sci., Camb. 72: 451454.CrossRefGoogle Scholar
Thimonier, J. and Pelletier, J. 1971. [A genetic difference in the preovulatory release of LH in ewes the Ile-de-France breed: its relation to number of ovulations.] Annls Biol. anim. Biochim. Biophys. 11: 559567.CrossRefGoogle Scholar
Williams, A. H. and Cumming, I. A. 1982. Inverse relationship between concentration of progesterone and nutrition in ewes. J. agric. Sci., Camb. 98: 517522.CrossRefGoogle Scholar
Wuttke, W., Hohn, K. G., Honma, K., Hllgendorf, W. and Lamberts, R. 1980. Interrelationships between prolactin and gonadotrophins. In Central and Peripheral Regulation of Prolactin Function (ed. MacLeod, R. M. and Scapagnini, U.), pp. 221236. Raven Press, New York.Google Scholar