The effects of extended photoperiod and warmth on hair growth in ponies and horses at different times of year


Autoři: Christiane O’Brien aff001;  Megan Ruth Darcy-Dunne aff002;  Barbara Anne Murphy aff002
Působiště autorů: Equilume Ltd., Naas, Co. Kildare, Ireland aff001;  School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland aff002
Vyšlo v časopise: PLoS ONE 15(1)
Kategorie: Research Article
doi: 10.1371/journal.pone.0227115

Souhrn

Photoperiod is considered the most dominant environmental cue allowing animals to anticipate and adapt to seasonal changes. In seasonally breeding mammals, changes in daylength alter pineal melatonin secretion and pituitary prolactin secretion. During the seasonal transition to shorter winter daylengths, increased production of melatonin and declining prolactin are associated with triggering winter coat growth in many animals. Similarly, studies have shown that artificial extension of photoperiod suppresses melatonin secretion and lifts prolactin inhibition to activate moulting. Four longitudinal cohort studies were conducted to determine if extended photoperiod and warmth, provided by mobile light masks and rugs (horse blankets), could reverse the onset of winter coat growth, maintain the summer coat and accelerate winter coat shedding in horses and in ponies. Studies began at dates corresponding to the autumnal equinox, one month post-summer solstice, one month pre-winter solstice and one month post-winter solstice, respectively. To extend photoperiod to approximately 15h of light, commercially available head-worn light masks provided low intensity blue light to one eye until 11pm daily. Coat condition and shedding rate were scored and hair samples collected, measured and weighed bi-weekly. Data from control and treatment groups were analysed by repeated measures ANOVA. Results revealed that extended photoperiod 1) did not reverse winter coat growth when initiated at the autumnal equinox, 2) effectively maintained the summer coat in stabled horses when initiated one month post-summer solstice, 3) accelerated shedding in outdoor living horses when initiated one month pre-winter solstice and 4) did not accelerate shedding in indoor or outdoor living ponies when initiated one month post-winter solstice. To successfully manage equine coat growth while also preserving optimal thermoregulation in both competition and breeding stock correct timing of light application is crucial and requires careful monitoring of environmental temperature. Further studies are needed where variations in breed and management are considered.

Klíčová slova:

Artificial light – Hair – Horses – Light – Molting – Ponies – Winter – Telogen phase


Zdroje

1. Reppert SM, Weaver DR. Molecular analysis of mammalian circadian rhythms. Annu Rev Physiol. 2001;63: 647–676. doi: 10.1146/annurev.physiol.63.1.647 11181971

2. Murphy BA, Circadian and circannual regulation in the horse: Internal timing in an elite athlete. J Eq Vet Sci. 2019;76: 14–24.

3. Moore RY. Circadian rhythms: Basic neurobiology and clinical applications. Annu Rev Med. 1997;48: 253–266. doi: 10.1146/annurev.med.48.1.253 9046960

4. Bartness TJ, Goldman BD. Mammalian pineal melatonin: A clock for all seasons. Experientia. 1989;45: 939–945. doi: 10.1007/bf01953051 2680574

5. Rose J, Stormshak F, Oldfield J, Adair J. The effects of photoperiod and melatonin on serum prolactin levels of mink during the autumn molt. J Pineal Res. 1985;2: 13–19. doi: 10.1111/j.1600-079x.1985.tb00624.x 3831298

6. Fitzgerald BP, Davison LA, McManus CJ. Evidence for a seasonal variation in the ability of exogenous melatonin to suppress prolactin secretion in the mare. Domest Anim Endocrinol. 2000;18: 395–408. doi: 10.1016/s0739-7240(00)00058-8 10869858

7. Foitzik K, Krause K, Nixon AJ, Ford CA, Ohnemus U, Pearson AJ, et al. Prolactin and its receptor are expressed in murine hair follicle epithelium, show hair cycle-dependent expression, and induce catagen. Am J Pathol. 2003;162: 1611–1621. doi: 10.1016/S0002-9440(10)64295-2 12707045

8. Craven AJ, Nixon AJ, Ashby MG, Ormandy CJ, Blazek K, Wilkins RJ, et al. Prolactin delays hair regrowth in mice. J Endocrinol. 2006;191: 415–425. doi: 10.1677/joe.1.06685 17088411

9. Martinet L, Allain D, Weiner C. Role of prolactin in the photoperiodic control of moulting in the mink (Mustela vison). J Endocrinol. 1984;103: 9–15. doi: 10.1677/joe.0.1030009 6481296

10. Webster JR, Barrell GK 1985. Advancement of reproductive activity, seasonal reduction in prolactin secretion and seasonal pelage changes in pubertal red deer hinds (Ceruus elaphus) subjected to artificially shortened daily photoperiod or daily melatonin treatments. J Reprod Fertil. 1985;73: 255–260. doi: 10.1530/jrf.0.0730255 3968657

11. Geyfman M, Plikus MV, Treffeisen E, Andersen B, Paus R. Resting no more: re-defining telogen, the maintenance stage of the hair growth cycle. Biol Rev Camb Philos Soc. 2015;90: 1179–1196. doi: 10.1111/brv.12151 25410793

12. Gebbie FE, Forsyth IA, Arendt J. Effects of maintaining solstice light and temperature on reproductive activity, coat growth, plasma prolactin and melatonin in goats. J Reprod Fertil. 1999;116: 25–33. doi: 10.1530/jrf.0.1160025 10505053

13. Guerin MV, Wang XJ. Environmental temperature has an influence on timing of the first ovulation of seasonal estrus in the mare. Theriogenology 1994;42: 1053–1060. doi: 10.1016/0093-691x(94)90127-5 16727609

14. Schmidt K, Deichsel K, Arruda de Oliviera R, Aurich J, Ille N, Aurich C. Effects of environmental temperature and season on hair coat characteristics, physiologic and reproductive parameters in Shetland pony stallions. Theriogenology 2017;97: 170–178. doi: 10.1016/j.theriogenology.2017.04.035 28583602

15. Berson DM, Dunn FA, Takao M. Phototransduction by retinal ganglion cells that set the circadian clock. Science 2002;295: 1070–3. doi: 10.1126/science.1067262 11834835

16. Provencio I, Warthen DM. Melanopsin, the photopigment of intrinsically photosensitive retinal ganglion cells. Wiley Interdiscip Rev Membr Transp Signal. 2012;1: 228–237.

17. Walsh CM, Prendergast RL, Sheridan JT, Murphy BA. Blue light from light-emitting diodes directed at a single eye elicits a dose-dependent suppression of melatonin in horses. Vet J. 2013;196: 231–235. doi: 10.1016/j.tvjl.2012.09.003 23079244

18. Murphy BA, Walsh CM, Woodward EM, Prendergast RL, Ryle JP, Fallon LH, et al. Blue light from individual light masks directed at a single eye advances the breeding season in mares. Equine Vet J. 2014;46: 601–605. doi: 10.1111/evj.12153 23909505

19. Nolan MB, Walsh CM, Duff N, McCrarren C, Prendergast RL, Murphy BA. Artificially extended photoperiod administered to pre-partum mares via blue light to a single eye: Observations on gestation length, foal birth weight and foal hair coat. Theriogenology. 2017;100: 126–133. doi: 10.1016/j.theriogenology.2017.06.012 28708527

20. Thapan K, Arendt J, Skene DJ. An action spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humans. J Physiol. 2001;535: 261–267. doi: 10.1111/j.1469-7793.2001.t01-1-00261.x 11507175

21. Brainard GC, Sliney D, Hanifin JP, Glickman G, Byrne B, Greeson JM, et al. Sensitivity of the human circadian system to short-wavelength (420-nm) light. J Biol Rhythms. 2008;23: 379–386. doi: 10.1177/0748730408323089 18838601

22. West KE, Jablonski MR, Warfield B, Cecil KS, James M, Ayers MA, et al. Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans. J Appl Physiol. 2011;110: 619–626. doi: 10.1152/japplphysiol.01413.2009 21164152

23. Scraba ST, Ginther OJ. Effects of lighting programs on onset of the ovulatory season in mares. Theriogenology. 1985;24: 667–679.

24. Monecke S, Saboureau M, Malan A, Bonn D, Masson-Pevet M, Pevet P. Circannual phase response curve to single bright light pulses in human subjects. J Physiol. 2003;549: 945–952. doi: 10.1113/jphysiol.2003.040477

25. Parry A, Nixon A, Craven A, Pearson A. The microanatomy, cell replication, and keratin gene expression of hair follicles during photoperiod-induced growth cycle in sheep. Cells Tiss Org. 1995;154; 283–299.

26. Plikus MV, Mayer JA, de la Cruz D, Baker RE, Maini PK, Maxson R, et al. Cyclic dermal BMP signalling regulates stem cell activation during hair regeneration. Nature 2008;451: 340–344. doi: 10.1038/nature06457 18202659

27. Mount LE The concept of thermal neutrality. In: Heat loss from animal and man-assessment and control. Eds. Monteith J.L. and Mount L.E.. Butterworth & Co., London; 1973. pp. 425–435.

28. Morgan K, Aspång L, Holmgren S. Lower critical temperature of competition horses. EAAP, Dublin, 2007: session 12, abstract number 0723.

29. Morgan PJ, Mercer JG. Control of seasonality by melatonin. Proc Nutr Soc. 1994;53: 483–493. doi: 10.1079/pns19940059 7886049

30. Langlois B. Inter-breed variation in the horse with regard to cold adaptation: a review. Livest Prod Sci. 1994;40: 1–7.

31. Lauvergne JJ. Characterization of domesticated genetic resources in American camelids, a new approach. In: Proceedings of the European Symposium of South American Camelids, Eds: Gerken M. and Renieri C., University of Camerino Publishing, Camerino.; 1994. pp. 59–65.

32. Johnson A. Serum concentrations of prolactin, thyroxine and triiodothyronine relative to season and the estrous cycle in the mare. J Anim Sci. 1986;62: 1012–1020. doi: 10.2527/jas1986.6241012x 3086267

33. Dhakal P, Tsunoda N, Nakai R, Kitaura T, Harada T, Ito M et al. Annual changes in day-length, temperature, and circulating reproductive hormones in Thoroughbred stallions and geldings. J Equine Sci. 2011;22: 29–36. doi: 10.1294/jes.22.29 24833985

34. Goldman BD. Mammalian photoperiodic system: Formal properties and neuroendocrine mechanisms of photoperiodic time measurement. J Biol Rhythms. 2001;16: 283–301. doi: 10.1177/074873001129001980 11506375

35. Murphy BA, Martin A, Furney P, Elliott JA. Absence of a serum melatonin rhythm under acutely extended darkness in the horse. J Circadian Rhythms. 2011;9: 3. doi: 10.1186/1740-3391-9-3 21569251

36. Paul MJ, George NT, Zucker I, Butler MP. Photoperiod and hormonal influences on fur density and regrowth in two hamster species. Am J Physiol Regul Integr Comp Physiol. 2007;293: R2363–R2369. doi: 10.1152/ajpregu.00520.2007 17898117

37. Mirmahmoudi R, Souri M, Talebi J, Moghaddam A. Seasonal variation in hair follicle activity and fibre growth of both male and female Merghoz goats in Western Iran. Small Ruminant Res. 2011;100: 131–136.

38. Stachurska A, Robovský J, Bocian K, Janczarek I. Changes of coat cover in primitive horses living on a reserve. J Anim Sci. 2015;93: 1411–1417. doi: 10.2527/jas.2014-8668 26020917

39. MacCormack JAD, Bruce JM. The horse in winter–shelter and feeding. Farm Building Progress 1991;105: 10–13.

40. Young BA, Coote J. Some effects of cold on horses. Horse report at Feeders’ Day. Alberta, Canada, 1973: University of Alberta, Department of Animal Science.

41. Schrammel N, Deichsel K, Aurich J, Aurich C. A long-day light program accelerates seasonal coat changes but is without effect on semen and metabolic parameters in Shetland pony stallions. Theriogenology 2016;85: 946–953. doi: 10.1016/j.theriogenology.2015.11.003 26673622


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2020 Číslo 1