Dr. Barbara Murphy discusses the complex role that light has on horse physiology, especially in reproduction. She highlights the role of blue light in mares reproductive cycle and how it can be used to improve breeding efficiency. The Equilume light mask is discussed and how it can be used to help manage light exposure to benefit breeding. The conversation also touches on light's effects on gestation length, foal development, and horse health, providing practical advice for breeders on optimal light exposure and alternative lighting options.
Today's episode of the Stall Side Podcast is brought to you by Rood & Riddle Veterinary Pharmacy.
Hey Bart, how are you doing today.
I'm good, Peter.
How are you.
I'm great, thanks.
We've got a fascinating guest on the show today.
Absolutely.
Dr.
Barbara Murphy joining us from Ireland today.
And every time I am with Barbara, I learn something new.
She's really a fascinating person, incredibly smart, and she's done a lot of work in light with the horses.
And we typically think about lighting and its effect on breeding brood mares, but there's a lot more to it than that, that she's going to get into.
Absolutely, yeah.
I mean, the biggest use for light around here is advancing the mare's seasonality.
And so you drive around here at night and the lights are on in the barns, and that's getting these mares.
But she has actually developed, you know, like a mobile version of that, like a little face mask with a little bit of blue light there.
And I'm really looking forward to her talking about the effects of light on the reproductive system of the animal, but also touching on the other things it may do, because again, we're all subject to the light that we're under, and it actually alters their physiology.
So I'm really looking forward to what she can tell us about that does for horses.
Yep, yep.
She does a great job.
She's fascinating to listen to.
I learn something every time I'm with her.
So let's get her on.
Yep, that's great.
And on StoreSide this week, we have Barbara Murphy talking about the effects of lighting on your horse.
welcome to Stoolside.
Thank you Pete, thank you Bart, great to be with you guys.
Yeah, good to have you on the show with us today and we appreciate you taking time.
So why don't you take just a minute and tell us about yourself.
Okay, well I am from County Cork in Ireland and my background is I grew up like every other little girl, loving horses.
And when it came to choose a college degree, I had heard that if you did equine science, there was a chance you got to spend six months on a Kentucky stud farm.
And for somebody from County Cork in Ireland, the thought of being out in the bluegrass, working with the quality mares and foals out there on a big farm, I was sold.
And I loved science so I did a degree in equine science in Limerick, the University of Limerick.
And I got to spend nine months out on North Middletown Road, out on Creekview Farm with Coolmore for my work experience and became fascinated with the management of mares for breeding.
Got to work with amazing barns of ridiculously expensive animals and just had lots of questions.
And I wasn't always convinced by the answers that I got.
And it just kind of fired up in me an interest in what if we could do some more research on certain aspects.
After I finished my degree, I took a year out, worked on a stud farm in, I worked the sales in Kentucky, went to Australia, flew back with stallions, got to experience all of that.
And then worked on a stud farm in Ireland with Godolphin.
And again, I mean, I'm so lucky to have had those opportunities to work.
I worked with Arthur Hancock in stone farm at one point.
So I had a year and then decided I was encouraged actually by a professor I met in Kentucky during my time there at the late Dr.
Barry Fitzgerald to consider applying to graduate school, initially just to do a master's in the area of reproduction.
And I spent a lot of time studying for the GRE exams to get into grad school in the States and was blessed to be offered a scholarship to do my PhD ultimately at the Gluck Center in Kentucky.
And I joined Dr.
Fitzgerald's lab after rotating through virology and genetics and seeing many different aspects of the wonderful work that they do there.
But really, I had a love for reproduction initially.
And I started looking at why certain mares cycle all year round.
And he was looking at the metabolic signal that might be driving this.
And we were finding that obese mares tend to have these erratic cycles all year round and not shut down.
But at the same time, it was the early 2000s, and there was a huge interest in circadian rhythms.
And I started looking at, well, what was the daily signal driving the annual rhythm in these mares.
And I kind of went down a rabbit hole looking at clock genes and the light-dark cycle and how this is converted into a seasonal signal for seasonal breeding animals such as the mare and that long daylight and how that rhythm regulates reproduction.
And I actually spent six years working on my PhD because I managed to, and I'm so grateful for having been given the freedom to go a whole new path in equine science.
Chronobiology was not a well-known topic at the time.
And I got to visit and attend a lot of conferences related to biological rhythms.
And I actually, my interest at the time went from reproduction to looking at what happens when we disrupt our horse's body clock, particularly when we fly them across loads of time zones to race in the Melbourne Cup or go from east coast to west coast for competing.
How does jet lag affect them.
And we knew from the literature in other species that jet lag was an inability of our endogenous circadian rhythm to adapt to an abrupt new light-dark cycle.
We can only adjust by about one hour or 20 minutes a day to every new light-dark cycle.
So when daylight savings comes in, it takes about three days for your body to go, "Oh, the alarm clock is waking me up earlier".
But what if you then you fly them six hours to Dublin from Lexington or from east coast to west coast.
And to answer that question, I had to first determine if horses had circadian rhythms.
And at the basis of circadian rhythms is a molecular controlled network made up of these clock genes that are rhythmically expressed in every cell of our bodies and the horse's bodies.
And it was before the genome was sequenced.
So there was an awful lot of new techniques that there weren't kits to do in the old days.
You actually had to clone the genes, grow them up in bacteria and actually sequence them for the first time in the horse.
So I spent a lot of time looking at that area of clock genes and circadian rhythms.
And when I finished my PhD, I always had this idea that maybe we could manipulate the horse's rhythms using light to the eye, but not both eyes.
And it's kind of an interesting story where that came from.
It was late one night at Main Chance Farm when I was taking blood samples with Dr.
Fitzgerald from mares that had been catheterised.
And anyone knows, and you guys know, that if a mare has a jugular catheter, you're standing at her side to take a sample.
And we were taking samples at night time.
And he said, "Whatever you do, Barbara, don't shine the flashlight in the mare's eye".
And we used to have these little red flashlights.
They were quite bright at the time.
But he knew from having messed up in the past when he was doing his melatonin assays, that if he accidentally shone the light in the mare's eye while taking the sample, it immediately affected the level of the hormone in the blood that he was aspirating from the vein.
So it stuck with me that it was an immediate effect.
And it also, in years to come, I was thinking, "Well, that light would only have hit one eye".
And it had that strong effect on the production of melatonin in the brain and the immediate response.
So in my head, I was like, having spent time with these mares out in Kentucky in the stables where the lights stay on until 11 o'clock at night from December 1st, I wonder if they could be outside and still get the light, but if you could only give it to one eye.
And when I was lucky enough to get my faculty position at University College Dublin, that's where I started doing some research.
Could we manipulate melatonin and in turn the circadian rhythm and the annual rhythm of horses by just using light to one eye.
And to kind of circle back to my attendance at all of these biological rhythms conferences as part of grad school, blue light was the new kid on the block because they had discovered that all mammals have a new set of... Well, they're not new.
They've been there since the dawn of evolution of mammalian biology, but blue receptors or intrinsically photosensitive retinal ganglion cells are the very complex name for these new set of retinal receptors that are highly sensitized by blue light.
And blue light is simply short wavelength light, but the sun provides the highest amount of blue light.
So it has all the colours of the spectrum in white light, but it's highest in blue.
So it's the reason the sky is blue on a cloudless day.
There's more blue light scattering.
And we have evolved as have our horses to be really responsive to that blue light to set our body clocks and keep us in tune with the environment.
So that's where I thought, okay, I originally wrote multiple grants to see if I could look at a way to develop a treatment for preventing jet lag in racehorses.
There wasn't a whole lot of support for it at the time, but then I thought, what else do we use light for.
And then the breeding application came to me.
What if I could just show that instead of having to keep them in a box, we could give them a little LED light on their eye, let them outside, keep them moving, keep them out with the herd and have them cycling in time for our industry imposed timelines.
So that's kind of a little bit about the background of why I got interested in all of this.
Traditionally, like you said, we've put them in the stall and turned the lights on, left them on till 11 o'clock at night and then turned them off.
But there's some downsides to that, as you alluded to.
One, it's labor intensive.
Two, the horses are locked up.
They're not moving around.
So there's just a lot of expenses.
So tell us about the light mask that you developed.
The light is activated once.
It's a blue light over the right eye.
We have some mares that are missing a right eye, so we have to use a left eyed mask.
But in most cases, if you're catching a mare in the field, you like her to have full visibility of seeing you approach on the left.
So we put the cup on the right eye.
And basically, we have a little magnetic wand that you wave past because I learned very quickly you could not put an on off switch on a horse's head.
It wasn't going to work.
There were a lot of fails on the electronic engineering aspect of it.
But you wave a magnet past the cup and it turns on the light and it activates at 4pm for seven hours.
So if you activate it anywhere in the world, you breed horses, it's still usually bright still by four o'clock.
And the aim of the mask is just to extend day length to that key 15 to 16 hours of light a day.
And the light comes on at four.
They don't notice it.
It doesn't bother them.
We had to do activity studies and behavior pattern studies to show it had no effect on their grazing behavior or didn't bother them.
And then it turns off at 11pm.
So they're outside.
And a lot of people believed at the time that warmth and nutrition played an equally important role.
But what we found in our first study, which was actually the first large field trial, was done in Kentucky on Castleton Lions Farm.
And we had 26 mares outside from the 1st of December until the 10th of February.
They only came in every six weeks to get their feet trimmed.
They were not wearing blankets.
They were outside.
They were on maintenance feed.
And 80% of them had ovulated by the 10th of February with a single blue LED light on the eye.
I was full sure it wouldn't work, to be honest.
Marshall: You and me both.
Because I remember driving up Newtown Pike and seeing all those lights.
These things are going to run through the fence.
This is crazy to see those blue lights out there.
It was interesting, the first time I ever saw it.
So... they fell off so many times.
They got fried by water and like it getting into them.
The hardest thing was to make them durable.
But lo and behold, it worked really well.
And since then, as the design has been constantly, we're constantly updating and improving it, it really does work really well for it's equally effective.
And that's not to say that putting mares under lights doesn't work well, provided there's a high blue in that light.
An LED light will work better than a fluorescent or an incandescent, just because of the spectrum of light.
And there's absolutely no harm in ensuring that they're looked after and warm and well fed.
But we tend to overfeed our horses, let's face it.
They have plenty of nutrition.
It would be normal for mares in the wild to have a kind of a lack of nutrition for a certain period of the year.
That is normal.
But so that was, I mean, that was the initial mask and it was the first kind of easy market.
People understood lights to bring mares into season.
But I was also really interested in some research that I had read as part of my PhD showed that if you equally gave light to the pregnant mare in the last trimester of her pregnancy, and the original study done in 1982 by Hodge et al was actually done in mares kept in stables where they had a lovely crossover design where they had, I think they had about 40 mares.
20 of them, they put on 16 hours of stable light from the 1st of December and they had a control group.
And in the second year, they swapped the treatments.
And what they found was they showed the pregnancy length was reduced by 10 days in the mares that received light before they foaled.
Equally, the birth weight of the foals was increased by 10 pounds in the mares that foaled with light for the last 90 days.
And this kind of spurred me to ask for stud farms to show me their breeding records.
And almost consistently on large farms, if you look at the gestation length and marry it with the foal birth weight, you will see a 10 day and a 10 pound difference between January and June in that mares that are foaling early tend to have a longer pregnancy and lighter foals.
And mares that foal in the natural breeding season who have naturally been exposed to the extended day length have heavier foals and tighter gestation lengths.
And for a lot of breeders, this was counterintuitive.
How could she be carrying longer and have a less mature foal.
But when you understand what light regulates in a seasonal breeding animal, it's not just GnRH to turn on the ovaries and the testes.
It is IGF-1 prolactin.
So growth hormones, milk producing hormones, everything that helps that foal develop both in utero and get the best nutrition then when it's born.
So we decided, now that I had a tool to do so, and I'm going to go back to your point, Bart, about the fear of horses running through fences.
I did the first study on pregnant mares here in Ireland on a farm from a breeder who used to buy a lot of older, very valuable mares and tried to get one or two last foals out of them.
So these mares, older mares that have had multiple foals tend to be the ones that have the longer pregnancies because they have a bigger uterus that doesn't contract or are involute to the best as it would when they were a maiden mare.
So every year they have a little bit more space for a foal to grow into.
And again, as we know that the signal for foaling is the stress response of the foal running out of room.
When it gets the cortisol release, that stimulates the cascade of hormones that lead to the mare foaling.
So what if you can give a signal to give the mare the growth hormones that they would normally receive so the foal develops at the right pace in tune with what would have been the right time of year to foal that nature would have provided.
And what we saw was on this first study that mares foaled two weeks, we selected mares that had an average pregnancy length of 350 days in their previous three gestations.
So if you look at the normal gestation length for the mare foaling during the natural breeding season, and I'm talking about May, June, July, 335 days is the average for the mare.
But in our thoroughbred industry, 345 days is the average.
But the big problem is 20-25% of mares carry longer than 350 days.
And I went looking at the Weatherby's stud book and looked at all the averages and going, "Why aren't the industry worried about this?" I mean mares in the wild foal at the same time every year.
If they didn't, and if they had to have this constant foaling drift, species wouldn't have been very successful.
But normally, they have the signal to foal at the right time and they get back in foal quickly afterwards.
So what we found with this group of mares is they tightened up by two weeks on average.
Compared to the control group, there was an 11-day difference.
And compared to their own previous history, there was a two-week shortening.
And it doesn't mean that it's shortening gestation below what's normal.
It just means it's bringing them back to what would be considered somewhat normal.
So mares carrying 360 days were coming back to 340, 345.
And there was variability around that.
But we repeated it in the United Kingdom, in the US, in Japan on commercial farms, and the average was still 12-14 day reduction in these mares that carried over.
So that was great.
But we couldn't actually evaluate, well, is it actually helping foal development.
Because on commercial farms, you've got the different sire genetics from all the different mares.
So I trotted back to Kentucky and kind of piggybacked on another study that was going on at the Gluck Center where they had 30 mares all in foal and bred with the same semen.
So now you have a pretty homogenous sire effect.
We split the group as evenly as we could, and we simply put light masks on them the 1st of December on half of them.
And we saw a nine pound average difference in foal birth weight.
So here we're showing that light is helping with the gestation length timing, and it's also helping with foal development.
And what's really nice is you know you're kind of starting to do something that people are interested in when other researchers start repeating the experiments, and it really helps.
So a colleague of mine at the University of Veterinary Medicine in Vienna, Dr.
Christine Aurich, she has access to a large warm blood stud, and she repeated all of these studies in crossover designs using 40 mares.
And she saw similar results, not the extent of the gestation length reduction, because these were warm blood mares foaling at a normal time of year you would say, but she saw a five day reduction.
But interestingly she followed these mares and she saw that their foal heat ovulation occurred five days sooner, and that they cycled back well with a larger dominant follicle if the mare was under blue lights.
They also showed that the foals, their neutrophil lymphocyte ratio after 24 hours was higher in the foals that were born to the light mask wearing mares.
And you know when a mare foals there are some key markers that every good foal hand will monitor the timing of, when they are born, when they pass the meconium, when they get to their feet, when they nurse.
And we looked at all those timings and found that the foals stood 15 minutes faster if the mare had 90 days of light before her due date, which is a pretty good sign that they're more mature.
So this was something that I think a lot of people accept that they're going to have a lot of, a certain proportion of their mares that will carry over and they'll say, "Oh she does it every year".
But one of the things I don't think people realise is we have shifted the circa-annual rhythm of the mare by putting them under lights on the 1st of December to conceive.
We need to return that light at the same time the following year so they see light in the last months of their pregnancy.
That turn on the hormones so that they're incubating the future athletes that we want to perform.
And another interesting fact is the fastest average daily gain in a horse's life is in the last three months in utero.
After they're born, their average daily gain in weight reduces every single day.
You don't quite get that growth period and that incubation back.
And in the environment, the mare and the light that she's exposed to changes the hormones in her circulation which communicate to the foal.
We know they communicate to the foal because we also looked at the hair coat in foals.
You mentioned that there are lots of other applications of the light mask outside of breeding for the showing horse.
You know that they were shed out because the hair coat cycle is a function of the warmth of the environment and the light that they're receiving through the hormone prolactin.
Well, a foal in utero is in a pretty warm, consistent environment.
But the mare's prolactin levels also inform it of the season it is being born into.
And we measured the hair length of foals born to mares that have received light from the light mask or under natural photo period being born in February and March.
And you find that they're born with a significantly shorter hair coat.
So it's affecting the growth of their hair.
It's also affecting other aspects of their physiology and it's probably the reason why they're born heavier because IGF-1 is also a function of light and the duration of light and it's also the hormone responsible for bone mineralisation in utero.
So all of these things together, I think it's a really exciting concept that a lot of farms could utilise better in just understanding that.
And they don't have to do it using a light mask.
They can do it using floodlights.
They can do it using stable light.
Or when I speak to most breeders, they say, "Oh yeah, we use lights for our pregnant mares".
And I'll say, "Well, when do you bring them in under lights?" "Oh, the last 30 days".
"Well, if you were trying to get a mare to cycle and turn on her hormones for her ovaries, would you only give her 30 days of light or would you give her the 7, 8, 10 weeks that she needs beforehand?" So even if they were to use a light mask or bring them in sooner from the 1st of December, even if they're foaling in March, they could still come in the 30 days and then switch into using the stable light.
But what it really eliminates is this problem with breeder C with early foaling mares that shut down post foaling.
It's not that they've shut down, they've just never had the signal to activate their ovaries.
So they'll have their foal heat, and then you've wasted all this time getting, or you will waste the time trying to get her to cycle back.
And some people use the term lactational anestrus, where they don't cycle after foaling.
Don't actually think that actually occurs in horses.
And the fact that is, in most cases, is they're foaling out of their normal season and without the light, they're just not cycling post foaling.
So it could be a way to really improve farm efficiencies and have a tighter foaling season if light was used properly.
That was a lot of information.
Yeah.
Sorry, I know, I get excited about it.
Can you back up though and give me just a little bit of a practical application for our listeners.
So when should these foaling mares come under lights.
So we're getting into December now.
So if somebody's thinking, gosh, I've got a mare that's due the 1st of February, am I too late now anyway.
Or on the other side of it, I have a mare that's due in May.
Does she even need to be under lights.
But there is also, people will hear me say, oh, 90 to 100 days is optimum.
That's what we saw in our research studies.
But if you have a January foaling mare, you don't want to start the light before November 15th, which we're past now, because they have to see a winter photo period to respond to the longer photo period.
So horses will respond to that shift from short day to long day.
But what I think is that if you start using it from the 1st of December on all of your stock, everything will eventually come back in line with the earlier breeding season.
If it was a May foaling mare, I would just back her up three months.
I would go 90 to 100 days before her due date and make sure then that she was getting good quality light that it's at least 16 hours from dawn to dusk.
So to help with all of those factors for sure.
But it's probably, and where it helps the breeders is obviously you might not want a May foal.
If you could scrape a few days, would it be a more marketable animal if it was an April foal.
Does it give you more time to get her back in.
And we have seen that because a lot of people go, "Oh, I can't do this for all my pregnant mares, but I'll try it on a few problem ones that I know are late".
Or they'll be, "I have a few maiden foaling mares that I want to have cycling after they foal, and they'll try them on that".
And they've had huge success.
And it usually takes three or four, they try it on three or four and they see and eventually some farms are starting to go the route of, "Okay, we need this on everything".
But a lot of people just, I don't know how well I do at explaining it, but it's just that idea that if there is a way for us to put light on horses, pregnant mares, at the same time as our dry mares to avoid all of these breeding inefficiencies that we've created by foaling them, at the only time of year that they wouldn't be cycling.
Because mares are generally cycling right into November.
When we did that first study, the vets couldn't believe it that we could not find a group of 40 anastros mares.
They were all still cycling into late November.
When they did shut down and we still had to say, "Okay, it doesn't matter whether they're cycling or not, we're still going to put light masks on them December 1st".
They would still cycle out despite having the light because it takes eight to 10 weeks to respond.
They would still cycle out and shut down probably for, it was usually the end of December to the start of February.
They would just be out and then they come back in again.
So it's that lag effect of the previous photo period that they're responding to.
So it really is the three months that we want them cycling in the thoroughbred industry that they're most likely not going to be.
So, yeah.
No, that's good practical advice.
So you mentioned earlier fluorescence are not the greatest lights to have horses under.
So the light mask is one option.
What are the alternative best options to the mask if you're just wondering- - Well, I am a little bit, yeah.
I mean, I'm a little bit biased on this because we did develop a stable lighting system for that very reason that has a higher level of blue.
You can get good blue or blue enriched LED or general LED lights.
What we have done with ours is ensure that the same blue light that stimulates the receptors that has the optimum effect at suppressing melatonin by night is in our stable light.
But the stable light that we also developed, while blue light is the most important for turning off melatonin, for allowing our horses be alert by day, for regulating the circadian rhythm.
One of the big problems we also have in the industry is we interact with horses 24/7.
We will go in and feed our racehorses early in the morning or take them out or turn on lights to check a mare, giving it medication.
Every time you turn a white light on over a horse, their melatonin hits the floor.
There is no part in our evolution as a species or in mammalian evolution where the sun came up in the middle of the night.
There might be solar eclipses in the middle of the day, but at no point does the sun come up.
Our bodies and our horses' bodies cannot handle that.
It causes a stress response and it also causes the circadian rhythm to flatline.
I've shown this in looking at clock gene rhythms in peripheral tissues of racehorses that are kept in lovely stables.
They have skylights.
I worked with a trainer who was really a big believer in the more natural light the better, which was great.
But the feed guy went around at four in the morning and turned on the light to throw in the feed.
Or they did something, they came back from the race as late, they turned all the lights on in the barn.
I took hair samples every two hours from the mane and isolated the RNA in the hair follicle cells and could show that the clock genes were on a flatline.
They had no rhythm.
We changed to this lighting system we were developing where instead of darkness at night, I tested the wavelength of red light that allows melatonin to rise at night.
So whereas the receptors in the back of the retina are highly stimulated by blue light, which is short wavelength high energy light, long wavelength red light is at the other side of the spectrum and these receptors don't see it.
So what it allows is, it allows us to see the horses in a dim red light condition, but it doesn't disrupt their body clock.
After a number of weeks under this blue enriched light by day, red at night, these horses had beautiful rhythms in their peripheral tissues.
And if you think about what the circadian system controls, it controls almost every aspect of physiology.
Every cell in your body has a clock and it controls what genes are turned on and off in tune with the environment and in harmony with other organs.
So if you can improve that, you're improving their immune system, their ability to heal, their recovery, their ability to regenerate at night.
If you exercise horses in the morning, in the evening is when they will start to build more muscle, provided they have a lighting that entrains their body to the right signal and have a strong circadian rhythm.
So for some breeding stock, in particular for foaling mares, when you want to watch them, you don't want to interrupt them, you want to see what's going on, the stable light that dims down to red at night has been really effective both for that and for a lot of, I mean it's a place where I hope it will have applications in rehabilitation centres and isolation units where you can still interact with the animals to give whatever medication you need, but you're not putting on a white light at night.
When they do this in humans, in hospitals, and there's a brilliant researcher at Cincinnati Children's Hospital who I recently visited, John Hoganesh's lab, and they do have done some amazingly convincing work where they've showed that recovery times can be almost halved if you put the patients under circadian lighting.
So their body can heal themselves by just being allowed to have a good, strong circadian rhythm.
So it's really big in the field of chronotherapy and medicine now is where our nursing homes, our ICUs, are a lot of different places where lighting can have such an important effect on the body.
So yes, ideal lighting in stables, blue enriched, white light by day.
Ideally, keep the horses in darkness at night.
That was the lovely thing about the light mask.
The horses are outside.
You don't have to worry about the nighttime interaction.
But make sure that you don't do nighttime checks with bright white flashlights.
You don't turn on white lights.
Find a way to just limit.
It's light pollution at night.
They like to bring them up and then they like to go to bed.
But those lights do need to go off.
They do have to have a dark period.
And I think people forget that sometimes.
Yeah, yeah.
Hey, well, this has been fabulous.
Thank you for sharing all that with us.
I know there's a lot that we still have to get to, but we might have to split this into two shows and have you back and talk about some of the other applications as well.
But I think you hit on all the points we wanted to hit too on the rooting.
Because I think one thing to take away from this is the profound effects that light have not only on the reproductive system, which we've sort of dwelled on, but you've sort of alluded to the fact that there's multiple other systems in the body that are actually affected by these clock chains.
And we can sort of start to think of some things from a medical sort of standpoint, like sort of other things that are affected by seasonality.
I mean, a classic one is going to be pituitary palsy, intermediate dysfunction, Cushing's.
You're sort of starting to think, "Hey, okay, that actually has a seasonal effect on that condition".
So you start to think about whether this light can actually have a beneficial effect there.
So yeah, I'm with Bart.
So you've earned yourself a second.
And that just published it.
And in fact, that it's still quite unclear what the mechanism is, but it seems to significantly improve with hypertrichosis and the hair coat improvements, but also of the 52 owners of PPID horses with an average age of 23, they were quite old and really well looked after.
But the reports were that their clinical signs of disease were significantly reduced in allowing them to have blue enriched light for extended periods every day.
So there's lots of really interesting avenues.
Head shaking syndrome is another seasonal one that seems to affect geldings more than mares.
And we have some nice preliminary data showing that in some horses it can work really well to help with that condition as well.
But it's an exciting area of research and yeah, thank you so much for the opportunity.
And again, I think absolutely you've earned yourself another session because what you've just started talking about would be very impactful around here, because as the equine population gets older, the problems you've just talked about are becoming more and more prevalent and there's only so much medication can do.
So if we can manipulate light to actually restore a little bit of homeostatic normality to some of these horses, potentially we can actually improve their lot.
You know, how walking into the barn just casually turning on the light can have a significant effect.
And you know, the light pollution, what effect that can have.
So it's interesting.
It's things that we really don't think about that you've brought to light.
You know, when you get up in the middle of the night to use the restroom- - I was thinking about that.
Do not look at your phone, for God's sake.
Use night shift on your iPhones.
And if you want to wake up in the morning, first thing you do is look at, if you want to wake up, look at your phone.
But I actually, I got, I said I better practice what I preach.
And the last biological rhythms conference I was at, there's a few trade, there's a trade area.
I actually bought blue light glasses.
So whenever I'm travelling for the 30 minutes, as soon as I wake up first thing in the morning, 30 minutes of blue light right on my eyes, and it resets your body clock and helps you overcome jet lag, so.
Yeah, fabulous.
That's great advice.
So Bar, no Instagram scrolling at three in the morning.
Okay.
Okay.
Yeah.
And so that was Stoolside for this week.
We've been talking to Barbara Murphy about the profound effects of light on the physiology of the horse.
Concentrating on reproduction, but we've covered a number of other topics as well.
See you next time.