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Home / Equine Research Bank / Animals (Basel) / Optimised Stable Lighting Strengthens Circadian Clock Gene R...
Animals : an open access journal from MDPI2023; 13(14); doi: 10.3390/ani13142335

Optimised Stable Lighting Strengthens Circadian Clock Gene Rhythmicity in Equine Hair Follicles.

Abstract: Hair follicles (HF) represent a useful tissue for monitoring the circadian clock in mammals. Irregular light exposure causes circadian disruption and represents a welfare concern for stabled horses. We aimed to evaluate the impact of two stable lighting regimes on circadian clock gene rhythmicity in HF from racehorses. Two groups of five Thoroughbred racehorses in training at a commercial racehorse yard were exposed to standard incandescent light or a customized LED lighting system. The control group received light from incandescent bulbs used according to standard yard practice. The treatment group received timed, blue-enriched white LED light by day and dim red LED light at night. On weeks 0 and 20, mane hairs were collected at 4 h intervals for 24 h. Samples were stored in RNAlater at -20 °C. RNA was isolated and samples interrogated by quantitative PCR for the core clock genes: ARNTL, CRY1, PER1, PER2, NR1D2, and the clock-controlled gene DBP. Cosinor analyses revealed 24 h rhythmicity for NR1D2 and PER2 and approached significance for CRY1 (p = 0.013, p = 0.013, and p = 0.051, respectively) in week 20 in the treatment group only. No rhythmicity was detected in week 0 or in week 20 in the HF of control horses. Results suggest that lighting practices in racehorse stables may be improved to better stimulate optimum functioning of the circadian system.
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Publication Date: 2023-07-17 PubMed ID: 37508112PubMed Central: PMC10376498DOI: 10.3390/ani13142335Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research study aims to analyze the effects of different stable lighting regimes on the circadian rhythm of racehorses. It indicates that customized LED lighting, comprising both blue-enriched white light during the day and dim red light at night, notably enhances the rhythmicity of certain ‘clock genes’ in horses.

Objectives & Methodology

  • The main goal of the research was to scrutinize the influence of two disparate stable lighting systems on the rhythmicity of circadian clock genes in the hair follicles of racehorses.
  • Two groups of five thoroughbred racehorses were selected for the study, and they were trained at a commercial racehorse yard. One group was exposed to standard incandescent light while the other experienced a personalized LED lighting system.
  • The incandescent light group mirrored the typical yard practices while the LED group was exposed to timed, blue-tinted white LED light during the day and dimmed red LED light at night.
  • To gauge the impact on the circadian clock genes, mane hairs from the horses were collected every 4 hours over the course of 24 hours at the start (0 week) and end (20 weeks) of the experiment.
  • The genes related to the circadian clock (ARNTL, CRY1, PER1, PER2, NR1D2), and a clock-controlled gene DBP were monitored using quantitative PCR in the isolated RNA samples.

Findings & Conclusions

  • Interestingly, 24-hour rhythmicity for NR1D2 and PER2 was detected in the LED light-exposed group in the 20th week of the trial and almost reached statistical significance for CRY1.
  • The rhythmicity of these genes was not observed in either week 0 or week 20 in the control horses who were exposed to standard incandescent light.
  • The results thus hint at the fact that altered stable lighting practices, particularly the use of a timed, color-adjusted LED lighting system, can stimulate an optimum function of the circadian system in racehorses.
  • This study offers insights into how lighting environmental modifications (>can potentially impact animal welfare, enhance their physiological regulation, and possibly, performance).

Cite This Article

APA
Collery A, Browne JA, O'Brien C, Sheridan JT, Murphy BA. (2023). Optimised Stable Lighting Strengthens Circadian Clock Gene Rhythmicity in Equine Hair Follicles. Animals (Basel), 13(14). https://doi.org/10.3390/ani13142335

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 13
Issue: 14

Researcher Affiliations

Collery, Aileen
  • School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Dublin, Co. Dublin, Ireland.
Browne, John A
  • School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Dublin, Co. Dublin, Ireland.
O'Brien, Christiane
  • Equilume Ltd., W91 TP22 Naas, Co. Kildare, Ireland.
Sheridan, John T
  • School of Electrical, Electronic and Mechanical Engineering, University College Dublin, Belfield, D04 V1W8 Dublin, Co. Dublin, Ireland.
Murphy, Barbara A
  • School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Dublin, Co. Dublin, Ireland.

Grant Funding

  • n/a / Irish Research Council Enterprise Partnership Scheme Postgraduate Scholarship
  • n/a / Equilume Ltd

Conflict of Interest Statement

B.A. Murphy and J.T. Sheridan (recently deceased) are cofounders of Equilume Ltd., a spin-out company deriving from their research at University College Dublin, and are members of the company’s Board of Directors. C. O’Brien was an employee of Equilume Ltd. at the time of the study. None of the authors have any other financial or personal relationships that could inappropriately influence or bias the content of the paper.

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Citations

This article has been cited 6 times.
  1. Parmantier S, Kyriazopoulou P, McClendon M, Adams A, Murphy BA. Influence of Extended Photoperiod Using Blue Light Masks on Hypertrichosis, Coat Condition and General Health Parameters in Horses with Pituitary Pars Intermedia Dysfunction. Animals (Basel) 2025 Oct 5;15(19).
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