Topic:Artificial Lighting
Artificial lighting in equine environments refers to the use of non-natural light sources to influence horse behavior, physiology, and management practices. This technique is often employed to extend daylight hours, which can affect reproductive cycles, coat shedding, and overall activity levels in horses. The use of artificial lighting is particularly relevant in breeding programs to manipulate estrous cycles and in performance settings to optimize training schedules. Research in this area explores the impact of light intensity, duration, and spectrum on equine health and welfare. This page compiles peer-reviewed research studies and scholarly articles that investigate the effects, applications, and potential implications of artificial lighting on horses.
Artificial intelligence in smartphone video analysis for equine asthma diagnostic support. Equine asthma is a prevalent respiratory disease that negatively impacts horses' health and athletic performance. Traditional diagnostic methods are invasive and require specialised equipment. There is a need for a non-invasive, cost-effective screening tool that can be used by veterinarians and horse handlers in ambulatory settings. Objective: To assess the willingness of veterinarians and horse handlers to adopt such a tool (Questionnaire 1) and the challenges associated with visually recognising equine asthma (Questionnaire 2) and to develop EquiBreathe, an artificial intelligence (AI)-powe...
Analytical Data Review on an Artificial Intelligence Platform for Doping Control in Horse Racing. In the screening of prohibited substances (PS) in horse biological samples with gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) for doping control, an enormous number of chromatograms are generated. Reviewing these chromatograms to identify suspicious findings requires an extensive manual effort. Recent advancements in Artificial Intelligence (AI) enable its use to classify images into different categories. This can potentially be utilized to perform first-line analysis of chromatograms, which are usually displayed as images, by classifying them...
Agreement between subjective gait assessment and markerless video gait-analysis in endurance horses. Subjective evaluation of gait by official endurance veterinarians (OEVs) is used to determine 'fitness-to-compete' in horses participating in endurance competitions. Objective gait analysis systems could aid in quick and verifiable judgements. Objective: To assess the agreement between objective analysis of head and pelvis vertical movement asymmetry performed with a markerless artificial intelligence motion tracking system (AI-MTS) and subjective lameness assessment performed by an accredited FEI OEV to judge horse gaits. Methods: Cross-sectional. Methods: During three endurance competitions,...
The virucidal potential effects of violet-blue light on influenza D virus. Influenza D virus (IDV) is a novel influenza virus, first isolated from swine with influenza-like symptoms in the USA in 2011. To date, IDV circulation has been reported in various animal species such as cattle, pigs, horses with the ability to expand its range of hosts. UV radiation has been widely used for the disinfection of various sources such as water, air, and surfaces, especially in places at greater risk of contamination by viruses and bacteria, such as hospitals and health facilities. The aim of this study was to evaluate the potential virucidal effect of a violet-blue light against ...
AI-assisted Digital Video Analysis Reveals Changes in Gait Among Three-Day Event Horses During Competition. The value and welfare of a performance horse are closely tie to locomotor behaviors, but we lack objective and quantitative measures for these characteristics, and qualitative approaches for assessing gait do not provide measures suitable for large-scale biomechanical research studies. Digital video analysis utilizing artificial intelligence-based strategies promise to meet the need for an economical, accurate, repeatable and objective technique for field quantification of equine locomotion. Here we describe pilot work using a consumer-level digital video camera to capture high-resolution and ...
A multi-task learning model for clinically interpretable sesamoiditis grading. Sesamoiditis is a common equine disease with varying severity, leading to increased injury risks and performance degradation in horses. Accurate grading of sesamoiditis is crucial for effective treatment. Although deep learning-based approaches for grading sesamoiditis show promise, they remain underexplored and often lack clinical interpretability. To address this issue, we propose a novel, clinically interpretable multi-task learning model that integrates clinical knowledge with machine learning. The proposed model employs a dual-branch decoder to simultaneously perform sesamoiditis grading ...
Explainable machine learning for assessing upper respiratory tract of racehorses from endoscopy videos. Laryngeal hemiplegia (LH) is a major upper respiratory tract (URT) complication in racehorses. Endoscopy imaging of horse throat is a gold standard for URT assessment. However, current manual assessment faces several challenges, stemming from the poor quality of endoscopy videos and subjectivity of manual grading. To overcome such limitations, we propose an explainable machine learning (ML)-based solution for efficient URT assessment. Specifically, a cascaded YOLOv8 architecture is utilized to segment the key semantic regions and landmarks per frame. Several spatiotemporal features are then ex...
Artificial mitochondrial transplantation (AMT) reverses aging of mesenchymal stem cells and improves their immunomodulatory properties in LPS-induced synoviocytes inflammation. Nowadays, regenerative medicine techniques are usually based on the application of mesenchymal stem cells (MSCs) for the repair or restoration of injured damaged tissues. However, the effectiveness of autologous therapy is limited as therapeutic potential of MSCs declines due to patient's age, health condition and prolonged in vitro cultivation as a result of decreased growth rate. For that reason, there is an urgent need to develop strategies enabling the in vitro rejuvenation of MSCs prior transplantation in order to enhance their in vivo therapeutic efficiency. In presented study, we attemp...
Plasma melatonin concentration during the early post-partum period in Thoroughbred mares and their foals. The authors aimed to determine the plasma melatonin concentration in mares and their new-born foals in the early post-partum period. Blood samples were collected from the jugular vein of 53 mare-foal pairs within twelve hours after parturition. Plasma melatonin levels were measured by ELISA. The melatonin concentration, adjusted for the moment of parturition using a generalised linear model, was 34.58 pg mL-1 in mares. It was significantly lower (27.63 pg mL-1) in the new-born foals. However, the melatonin concentration declined differently by the end of the twelve hours, it decreased less in...
Optimised Stable Lighting Strengthens Circadian Clock Gene Rhythmicity in Equine Hair Follicles. 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...
Effect of short-term artificial light and transvaginal progesterone device on first ovulation in late transitional mares. In study I, plasma progesterone concentrations were evaluated in anoestrous mares that received an intravaginal progesterone release device (IPRD) for 10 days. Mares were divided into 3 groups based on the dosage of progesterone (0 g, n=3; 1.38 g, n=5; and 1.9 g, n=5). No statistical differences were found in plasma progesterone concentrations between the two doses tested. In study II, the effects of a protocol based on a short program of artificial light combined with an IPRD containing 1.38 g of progesterone on oestrous behaviour and onset of ovulation were evaluated. IPRDs were inserted int...
Development of Foals Until One Year of Age When the Dam was Exposed to Blue Monochromatic Light Directed at One Eye During Late Pregnancy. In horses, blue LED light directed at one eye of pregnant mares shortens gestation length and results in the birth of foals with lower wither heights, similar weight and reduced hair length compared to controls. In this study, we have therefore analysed postnatal development of foals born to either blue LED light-treated (n = 20) or control mares (n = 20). Size, weight and hair coat changes were determined for 1 year and heart rate, heart rate variability (HRV) and selected haematology parameters for 1 month. Haematocrit decreased (P < .001) and leukocyte and lymphocyte counts increased...
Effects of blue monochromatic light directed at one eye of pregnant horse mares on gestation, parturition and foal maturity. Blue light directed at 1 eye advances the equine ovulatory season but may also advance foaling. In this study, effects of blue LED light on pregnancy outcome were assessed. A total of 20 mares with singleton pregnancies were studied over 2 consecutive years in a cross-over design. In 1 year, mares received an extended photoperiod using 50 lux of blue LED light (468 nm) directed at a single eye from 08:00 until 23:00 daily via head-worn light masks starting mid-December and in the other year remained untreated as controls. Gestation was shorter in blue LED light-treated than in control pregnan...
The Effects of Red Light on Mammalian Sperm Rely upon the Color of the Straw and the Medium Used. Previous research has determined that irradiation of mammalian sperm with red light increases motility, mitochondrial activity, and fertilization capacity. In spite of this, no study has considered the potential influence of the color of the straw and the extender used. Therefore, this study tests the hypothesis that the response of mammalian sperm to red light is influenced by the color of the straw and the turbidity/composition of the extender. Using the horse as a model, 13 ejaculates from 13 stallions were split into two equal fractions, diluted with Kenney or Equiplus extender, and stored...
Red-Light Irradiation of Horse Spermatozoa Increases Mitochondrial Activity and Motility through Changes in the Motile Sperm Subpopulation Structure. Previous studies in other mammalian species have shown that stimulation of semen with red-light increases sperm motility, mitochondrial activity, and fertilizing capacity. This study sought to determine whether red-light stimulation using a light emitting diode (LED) at 620-630 nm affects sperm motility and structure of motile subpopulations, sperm viability, mitochondrial activity, intracellular ATP levels, rate of O consumption and DNA integrity of horse spermatozoa. For this purpose, nine ejaculates were collected from nine different adult stallions. Upon collection, semen was diluted in Ke...
Irradiating frozen-thawed stallion sperm with red-light increases their resilience to withstand post-thaw incubation at 38 °C. The aim of this study was to evaluate whether red-light stimulation increases the longevity and resilience of cryopreserved stallion sperm to withstand post-thaw incubation for 120 min. Sixteen frozen straws of 0.5 mL from eight stallions were used. Samples were cryopreserved, thawed through incubation at 38 °C for 30 s and divided into the control and samples exposed to red-light using a triple LED photo-activation system (wavelength: 620-630 nm). Three irradiation protocols consisting of different light-dark-light intervals (1-1-1, 2-2-2 and 3-3-3 min) were tested. Sperm quality param...
The effects of extended photoperiod and warmth on hair growth in ponies and horses at different times of year. 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 longitudi...
Red light at night permits the nocturnal rise of melatonin production in horses. Exposure to white light at night suppresses melatonin production, impacts circadian rhythms and contributes to ill-health in humans. Human interaction with horses frequently occurs at night. We tested the hypothesis that dim red light would not suppress the nightly rise in serum melatonin levels in horses. In a crossover design, six horses were maintained for consecutive 48h periods under a Light: Red (LR) and a Light: Dark (LD) photo-schedule. Transitions from light (>200lux, polychromatic white light) to red (5lux, peak wavelength 625nm) or dark (0.05). A robust main effect of time (P<...
Circadian and Circannual Regulation in the Horse: Internal Timing in an Elite Athlete. Biological rhythms evolved to provide temporal coordination across all tissues and organs and allow synchronization of physiology with predictable environmental cycles. Most important of these are circadian and circannual rhythms, primarily regulated via photoperiod signals from the retina. Understanding the nature of physiological rhythms in horses is crucially important for equine management. Predominantly, they have been removed from exposure to their natural environmental stimuli; the seasonally changing photoperiod, continuous foraging and feeding activity, social herd interactions, and t...
Review: The potential of seminal fluid mediated paternal-maternal communication to optimise pregnancy success. Artificial insemination has been a landmark procedure in improving animal agriculture over the past 150 years. The utility of artificial insemination has facilitated a rapid improvement in animal genetics across agricultural species, leading to improvements of growth, health and productivity in poultry, swine, equine and cattle species. The utility of artificial insemination, as with all assisted reproductive technologies side-steps thousands of years of evolution that has led to the development of physiological systems to ensure the transmission of genetics from generation to generation. The ...
Half a century of equine reproduction research and application: A veterinary tour de force. Over the past 50 years, per season pregnancy rate in Thoroughbred mares have risen from 70 to >90% and foaling rates from 55 to >80%. Some of the significant pharmacological treatments and diagnostic methods which have driven this marked improvement in breeding efficiency are reviewed. They include the application of artificial lighting to hasten the onset of ovulatory oestrous cyclicity in early Spring, rapid steroid hormone assays to aid in determining the stage and normality of the mare's cycle, prostaglandin analogues, synthetic progestagens and Gonadotrophin-releasing Hormone (GnRH) anal...
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 at birth. In seasonally breeding animals, photoperiod perception is crucial for timing of important physiological events. In the horse, long day photoperiod influences the onset of ovulation and cyclicity, shedding of the heavier winter coat and the timing of parturition. In this compilation of studies, conducted across three breeding seasons and two countries, the impact of artificially extended day length was investigated on gestation length, foal birth weight and foal hair coat at birth. The light therapy was administered to pre-partum mares via mobile head worn masks which provided short wavelength ...
Deep anestrous mares under natural photoperiod treated with recombinant equine FSH (reFSH) and LH (reLH) have fertile ovulations and become pregnant. The most common equine breeding practice to decrease the time to the first ovulation of the year is to use artificial lights starting December 1 in the Northern Hemisphere. It can take 60-90 d for this lighting regimen to induce a fertile ovulation. The success rate for pharmaceutical compounds to carry out the same process has been variable. One compound that did induce an early ovulation was recombinant equine follicle stimulating hormone (reFSH), but neither pregnancy nor cyclicity was established in that study. Starting on December 1, 20 deep-anestrous mares of light horse breeds (4-15 y...
Effects of a long-day light programme on the motility and membrane integrity of cooled-stored and cyropreserved semen in Shetland pony stallions. Increasing day length in spring stimulates reproductive functions in horses. In this study, we have analysed the effect of artificial long days on the quality of cooled-stored and cryopreserved semen in Shetland stallions. Stallions of the treatment group (AL, n = 8) were exposed to 16 h light and 8h darkness from 15th December to 20th March while control stallions (CON, n = 7) were kept under natural photoperiod. Semen was collected once weekly and processed for cooled-storage and cryopreservation once per month. Total and progressive motility and percentage of membrane intact spermatozoa wer...
Promoting effects of an extended photoperiod treatment on the condition of hair coats and gonadal function in Thoroughbred weanlings. The effects of an extended photoperiod (EP) treatment (14.5 hr light, 9.5 hr dark) on Thoroughbred colts and fillies from December 25 at 7-9 months old to the following May at 12-14 months old on coat condition and gonadal functions were investigated. Coat condition was evaluated in April. The colts and fillies in the EP treatment group changed from winter to summer coats (molting of winter coats), whereas those in the control group did not. To determine the day of first ovulation, the plasma concentrations of progesterone were measured once a month in fillies. The day of first ovulation was a...
A long-day light program accelerates seasonal coat changes but is without effect on semen and metabolic parameters in Shetland pony stallions. Horses are seasonal breeders, and robust breeds may exhibit a winter hypometabolism when kept under semiferal conditions. In this study, we analyzed the effects of artificial long days on rectal temperature, heart rate, heart rate variability, hematology, coat changes, semen parameters, and plasma testosterone concentrations in Shetland stallions stabled overnight and assigned to a control group (CON, n = 9) kept under natural photoperiod, and a treatment group exposed to a long-day light program from 15 December to 20 March (AL, n = 9). During the 8-month study, rectal temperature, heart rate...
Effects of an extended photoperiod on gonadal function and condition of hair coats in Thoroughbred colts and fillies. The effects of an extended photoperiod (EP) in Thoroughbreds colts and fillies from winter at one year old to spring at two years old on the gonadal functions, coat condition, and endocrine changes were investigated. Sixty-two Thoroughbreds (31 colts and 31 fillies) reared in the Hidaka Training and Research Center (Hidaka), Japan Racing Association were used. Thirty of them (15 colts and 15 fillies) were reared under EP conditions from December 20 to April 10, and the remaining 32 horses were reared under natural light alone as a control group. For EP, a 100-watt white bulb was set near the c...
Blue light from individual light masks directed at a single eye advances the breeding season in mares. Artificial lighting is commonly used to advance the breeding season in horses. Light masks have been developed that direct light at a single eye to inhibit the production of melatonin, the decoder of photoperiod for seasonally breeding animals. Objective: To investigate whether low-intensity blue light from light masks was effective at advancing the breeding season in mares. Methods: Controlled experiment. Methods: Data on reproductive activity was collected from 3 groups of mares maintained on Kentucky horse farms under various lighting conditions between 20 November 2011 and 10 February 2012...
Blue light from light-emitting diodes directed at a single eye elicits a dose-dependent suppression of melatonin in horses. The production of melatonin during night-time hours decodes day length for seasonally breeding animals. The use of artificial light to advance the breeding season in mares is common practice within the equine industry. Four healthy Thoroughbred mares were used to evaluate the minimum intensity of light required to inhibit serum melatonin. Mares were fitted with indwelling jugular catheters and using a crossover design blood samples were collected following 1h exposure to light (barn lighting approximately 200 lux), dark (<0.1 lux), and 3, 10, 50, and 100 lux intensities. The light source wa...