DOI QR코드

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Fleece Phenotype Influences Susceptibility to Cortisol-induced Follicle Shutdown in Merino Sheep

  • Ansari-Renani, H.R. (Animal Science Research Institute) ;
  • Hynd, P.I. (Department of Agricultural and Animal Science, University of Adelaide) ;
  • Aghajanzadeh, A. (Animal Science Department, Islamic Azad University-Shabestar Branch)
  • 투고 : 2006.05.13
  • 심사 : 2007.02.20
  • 발행 : 2007.11.01

초록

This experiment was conducted to determine the extent to which susceptibility to cortisol-induced follicle shutdown is influenced by fleece phentotype. Twenty Finewool (10 sheep low fibre diameter, low coefficient of fibre diameter-LL and 10 low fibre diameter, high coefficient of variation of fibre diameter-LH) and twenty Strongwool (10 low fibre diameter, low coefficient of variation of fibre diameter-HL and 10 high fibre diameter and high coefficient of variation of fibre diameter-HH) sheep of 9 months of age were individually penned in an animal house and were injected intramuscularly with an aqueous suspension of hydrocortisone acetate at a rate of 1.42 mg/kg body weight for a period of two weeks. Fibre diameter was measured from clipped tattooed patch wool samples. Follicle activity was measured by histological changes in skin biopsies taken weekly. Blood samples were collected at two-week intervals and plasma cortisol measured. Increased plasma cortisol concentration significantly (p<0.05) reduced clean wool production and mean fibre diameter dropped to its lowest level four weeks after commencement and two weeks after the cessation of cortisol injection. Elevation of plasma cortisol concentration significantly (p<0.0001) increased the percentage of inactive follicles two weeks after injection started. High fibre diameter groups (Strongwool sheep; i.e. HL+HH) had significantly (p<0.0001) higher percentage of follicle shutdown than low fibre diameter groups (Finewool sheep; i.e. LL+LH). Average percentage of shutdown follicles for Finewool (LL+LH) and Strongwool (HL+HH) Merino sheep was $9.8{\pm}0.9$ and $13.5{\pm}0.9$ respectively. Shutdown of primary follicles was more pronounced in Finewool than Strongwool sheep. There was no significant effect of coefficient of variation of fibre diameter on propensity to follicle shutdown induced by exogenous cortisol. It is concluded that elevation in plasma cortisol concentration is inhibitory to the normal activity of follicles in Strongwool sheep but that variation in fibre diameter has little or no effect.

키워드

참고문헌

  1. Ansari-Renani, H. R. and P. I. Hynd. 2001. Cortisol-induced follicle shutdown is related to staple strength in Merino sheep. Livest. Produc. Sci. 69:279-289. https://doi.org/10.1016/S0301-6226(00)00253-0
  2. Auber, L. 1952. The anatomy of follicles producing wool-fibres, with special reference to keratinization. Transcripts of the Royal Society of Edinburgh. 62:191-254. https://doi.org/10.1017/S0080456800009285
  3. Bassett, J. M. 1963. The influence of cortisol on food intake and glucose metabolism in sheep. J. Endocrinol. 26:539-553. https://doi.org/10.1677/joe.0.0260539
  4. Boyd, J. M., J. M. Doney, R. G. Gunn and P. A. Jewell. 1964. The Soay on the Island of Hirta, St. Kilda. A study of a feral population. Proceeding of zoological society of London. 142:129-163.
  5. Chapman, R. E. 1989. Follicular malfunctions and resultant effects on wool fibres. In; The biology of wool and hair (Ed. G. E. Rogers, P. J. Reis, K. A. Ward and R. C. Marshall). Chapman and Hall, London. pp. 243-257.
  6. Chapman, R. E. and J. M. Bassett. 1970. The effects of prolonged administration of cortisol on the skin of sheep on different planes of nutrition. J. Endo. 48:649-663. https://doi.org/10.1677/joe.0.0480649
  7. Chapman, R. E. and M. H. Hardy. 1988. Effect of intradermally injected and topically applied mouse epidermal growth factor on wool growth, skin and wool follicles of Merino sheep. Aust. J. Biol. Sci. 41:261-268. https://doi.org/10.1071/BI9880261
  8. Hocking Edwards, J. E. and P. I. Hynd. 1991. Blood flow through the skin of high and low-wool producers. Proceed. Nutr. Soc. Aust. 16:206.
  9. Hynd, P. I., Hughes, A., Earl, C. R., and N. M. Penno. 1997. Seasonal changes in the morphology of wool follicles in Finewool and Strongwool Merino strains grazing at different stocking rates in southern Australia. Aust. J. Agric. Res. 48:1089. https://doi.org/10.1071/A97001
  10. Langlands, J. P. and J. L. Wheeler. 1968. The dyebanding and tattooed patch procedures for estimating wool production and obtaining samples for the measurement of fibre diameter. Aust. J. Exper. Agric. Anim. Husb. 8:265-269. https://doi.org/10.1071/EA9680265
  11. Lindner, H. R. and K. A. Ferguson. 1956. Influence of the adrenal cortex on wool growth and its relation to 'break' and 'tenderness' of the fleece. Nature, London. 177:188-189.
  12. Lynch, L. J. and N. A. Michie. 1973. Laser fibre fineness distribution analyser: A device for the rapid measurement of the mean and distribution of fibre diameter. Wool Technol. Sheep Breed. 20:23-27.
  13. Nixon, A. J. 1993. A method for determining the activity state of hair follicles. Biotech. Histochem. 68:316-325. https://doi.org/10.3109/10520299309105637
  14. Ryder, M. L. 1960. A study of the coat of the Mouflon Ovis Musimon with special reference to seasonal change. Proceed. Zool. Soc. London. 135:387-408.
  15. Schlink, A. C. and A. E. Dolling. 1995. Abnormal shedding contributes to the reduced staple strength of Western Australian Merinos. Wool Technol. Sheep Breed. 43:268-284.
  16. Slee. J. 1963. Birth coat shedding in Wiltshire Horn lambs. Anim. Produc. 5:301-316. https://doi.org/10.1017/S0003356100021838
  17. Slee, J. and M. L. Ryder. 1967. The effect of cold exposure on wool growth in Scottish Blackface and $Merino{\times}Cheviot$ sheep. J. Agric. Sci. Cambridge. 69:449-453. https://doi.org/10.1017/S0021859600019146
  18. Slee, J. 1959. Fleece shedding, Staple -length and fleece weights in experimental Wiltshire Horn-Scottish Blackface crosses. J. Agric. Sci. Cambridge. 53:209-233. https://doi.org/10.1017/S002185960002027X
  19. Spurlock, G. M. and M. T. Clegg. 1962. Effect of cortisone acetate on carcass composition and wool characteristics of weaned lambs. J. Anim. Sci. 21:494. https://doi.org/10.2527/jas1962.213494x
  20. Thwaites, C, J. 1972. The effects of short-term undernutrtion and adrenocortical stimulation on wool growth. Anim. Produc. 15:39-46. https://doi.org/10.1017/S0003356100011193
  21. Young, S. S. and R. E. Champion. 1985. Fleece characteristics and their influence in wool production per unit area of skin in Merino sheep. Aust. J. Agric. Res. 9:363-372. https://doi.org/10.1071/AR9580363

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