Interesting article about temperature regulation in horses. Worth a read

Perhaps a better question on this heat transfer issue would be: what proportion of heat loss comes about from convective heat loss (ie to the air surrounding) and what proportion from radiant heat loss? I would make an educated (though not expert!) guess that the former is larger.
 
apercrumbie said:
Perhaps a better question on this heat transfer issue would be: what proportion of heat loss comes about from convective heat loss (ie to the air surrounding) and what proportion from radiant heat loss? I would make an educated (though not expert!) guess that the former is larger.
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Good question! It would depend on a lot of factors - for radiant loss, distance from walls, temperature difference, surface area. For convective loss - temp difference, surface area, air movement. Its partly why we have moved to using the WBGT index to quantify thermal environmental stress as opposed to temp or temp and RH alone as these can be misleading. The WBGT index accounts for T, RH, wind and radiant load.
 
I've been positively cruel according to some, Denzel (a chunky Irish sort who holds weight like nobody's business) only saw a lightweight when it rained horrendously. He stayed naked during the snow and was absolutely fine. However this year we've moved onto clay and for him to stay in work and for me to stay sane he may need to be clipped and rugged - my worst nightmare as he has very little respect for electric fencing as is.

Can't contribute on the science front - kettle makes water warm for coffee and fridge makes wine cold is about as far as my understanding of heat transfer is prepared to go!
 
Dr David Marlin said:
Apparently, I have "spoilt" the thread by discussing science, at least according to YCBM.

Is this the view of most people?
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I started the thread so I get to decide if it's spoiled 😜 and the answer is definitely not. I like to understand things well enough to explain them to others and the scientific explanations are interesting.

I'm a minimal rugger, but then again I have a Highland Pony and a hardy furry Polish bred coloured who both live on fresh air. I can confidently say that if I owned the big cob in the next stable along he would not have been tucked up in his stable wearing a thick stable rug with a neck last night, he would be out naked with mine!
 
Mine are out naked too 24/7, and looking very happy and full of life. I am looking forward to the winter coats coming through and seeing them wrap themselves up in their natural anoraks.
 
Any chance of an old-fashioned link? My version of the new forum refuses to show anything embedded, I just get white space. Would love to share it to my yard's FB page.

I wish mine could stay out 24/7 but that's not available anywhere where I live. He's tucked up in a stable at night and I will be holding off rugging till his ears tell me he's cold. Unless it's horizontal rain all day he is going out nekkid as soon as the midgies are dead!
 
I’ll be honest, physics make sure my head hurt, so I’m not going to pretend I know anything about temperatures and walls and radiating heat... but I do know that my fit and healthy young mares are currently unrugged and will remain unrugged until they are fully clipped in a few weeks, when they will wear 50g filled lightweights. Once we hit the depths of winter, they go to 100g fills.

Mine haven’t seen a rug since early April... they’ll probably run a mile when I bring them out!
 
My ponies are roughing it this year - no stables, no rugs, just plenty of grass and natural shelter. If hell freezes over, I may consider sticking a rug on them. The mare hasn't seen more than a rain sheet in the worst of the wind and rain so far - it'll have to drop spectacularly for me to consider anything else as nobody has told her she isn't a nuclear reactor...
 
ester said:
oi there's some bright and knowledgeable people here too :p.
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Indeed there are, and funnily enough many of them don't feel the need to browbeat folk in a pompous and arrogant way. If all knowledgeable folk posted on here in the arrogant manner of 'Don't you know who I am' Dr David Marlin, this place would not be the mostly supportive environment that it is now.

It's quite possible to get your point across without resorting to attempts at humiliation. I actually enjoy reading the good dr's offerings on FB. It's as if he has a personality transplant when he comes on here.
 
There is a Facebook page I follow that makes me cringe with just how much they rug their horses. Tbh I’m surprised that they can move with the amount they have on, usually a minimum of 3 rugs! So it’s not just the tog of each rug either that would affect over rugging, the amount of rugs on will increase weight.

I have a bucas rug, which is 300g. Horse has worn it when was -9 to around 10-12 degrees yet each time when checked was warm, not cold or not hot. The temperature changes were dramatic from night to day and unfortunately I work during the day so rugs aren’t changed. This rug has been amazing though and he has never sweated up - why is that?
The rug has a half fleece lining so bottom half of rug is not filled, would that make the difference?
 
Ill throw myself to the dogs then and admit that my highland has been fully clipped 3 times since August and is still out 24/7 naked. He has lots of natural shelter in his field and we live in Bucks, not the Highlands but not once have I found him even remotely cold, tucked up or miserable. He did wear a light sheet on the 1 night about a week ago when we were predicted a much colder night but with temperatures back in high single figures at night this week he is back to "au natural". He is in the minority already on our yard, most are rugged already overnight, some in the daytime too!
 
Dr David Marlin said:
Apparently, I have "spoilt" the thread by discussing science, at least according to YCBM.

Is this the view of most people?
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I did not say you had spoilt the thread. I said you had spoilt your own argument doing the rounds on Facebook. Which is a shame because over rugging is a definite issue and it needs influential people to speak up about it.
 
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Dr David Marlin said:
Why not come on my Facebook page @DrDavidMArlin and debate your views? You may find its a little uncomfortable though as there are some very bright and knowledgeable people on there :)
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This forum is littered with people with PhD's David, please don't be so insulting to them.

Find me a physicist who understands live animals to reinforce your argument and I'll agree I am wrong.

Meanwhile, let's try this thought experiment.

Put a horse in a room where the air is at 15 degrees and keep the air at that temperature in a radius of, say, two feet around the horse while you cool the walls to zero. How much heat will the horse radiate? Exactly as much heat as is necessary to stabilize the horse's core temperature to the 38 degrees it needs to be.

Now heat the walls to 50 degrees while keeping that two foot radius of air around the horse at fifteen degrees. How much heat will the horse radiate? Exactly the same amount as when the walls were at zero, because the ambient temperature round the horse has not changed.

Walls do not have an attractive force for heat. They cannot "draw heat from horses" as you suggest. The only heat available to reach the walls from the horse does not change depending on the temperature of the walls. It changes depending on the temperature of the air around the horse.

Now consider the horse standing in a nice draught free stable, with its body heating up the air around it. The horse in the wooden stable is warming the air, and some of that warmth is escaping into the cold night air through the walls and roof of the stable. The identical horse next door is in a stone stable. That stone warmed up in the winter sunshine during the day, and is now releasing some heat into the stable. In addition, less of the heat being created by the horse is going to escape into the cold night air because a big thick bit of stone, concrete block, or brick is a better insulator than a thin piece of wood.

And for all those reasons, stone stables are warmer in winter to stable a horse in than wooden ones.


As per my signature, I am happy to admit when I am wrong. But you are not right about horses living in strone stables needing more rugging than horses in wooden ones.
 
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only_me said:
There is a Facebook page I follow that makes me cringe with just how much they rug their horses. Tbh I’m surprised that they can move with the amount they have on, usually a minimum of 3 rugs! So it’s not just the tog of each rug either that would affect over rugging, the amount of rugs on will increase weight.
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There's one I follow which is similar (or possibly the same) - come winter, every single inch is covered (well, except the feet and tail I suppose).
 
Sheep said:
There's one I follow which is similar (or possibly the same) - come winter, every single inch is covered (well, except the feet and tail I suppose).
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I imagine it’s the same, legs are always bandaged which can’t be good for them. Must take ages unrugging so can go ride! Will be interesting to see if they rug the new native the same way!
 
I certainly appreciated DabDabs additional input.

Regardless of how others view it I do think most people try to treat their horse as the individual it is. F has always been a hot pony and blanket or full clipped all winter and as such minimally rugged. Last winter he did the first half unclipped (and rugged) and is definitely not keeping himself as warm as he always used to. Much prefer to notice that change and act on it.
 
This is what a local rug washing place is posting on FB:

"Hi guys make sure you get your horse rugs ready , as the wet cold nights are here. We all like to be warm and cosy in our homes, just like our horses. They like to be warm and cosy to so keep them protected. Make sure your horse rugs are re/proofed and clean."

It is really mild here at the moment, it's been between 13 and 18 degrees in the daytime, and hasn't dropped below 4 at night time.
 
ycbm said:
This forum is littered with people with PhD's David, please don't be so insulting to them. DM - I wasnt - I was suggesting that you might not be able to dominate an open discussion as you try to do on here by shouting most people down.

Find me a physicist who understands live animals to reinforce your argument and I'll agree I am wrong. DM - You have several on here who have already commented but you have chosen to ignore them. I've also published a "few" papers on the physics of thermoregulation in live animals myself :)

Meanwhile, let's try this thought experiment.

Put a horse in a room where the air is at 15 degrees and keep the air at that temperature in a radius of, say, two feet around the horse while you cool the walls to zero. How much heat will the horse radiate? Exactly as much heat as is necessary to stabilize the horse's core temperature to the 38 degrees it needs to be. DM - The horse doesn't have a choice of how much heat it radiates. The amount of heat radiated by the horse to the wall is dependent on the temperature difference, the surface areas and the nature of the wall material.

Now heat the walls to 50 degrees while keeping that two foot radius of air around the horse at fifteen degrees. How much heat will the horse radiate? Exactly the same amount as when the walls were at zero, because the ambient temperature round the horse has not changed. DM - In this example the horse won't radiate any heat - it will be absorbing it from the wall - that's how radiant heaters work!

Walls do not have an attractive force for heat. They cannot "draw heat from horses" as you suggest. The only heat available to reach the walls from the horse does not change depending on the temperature of the walls. It changes depending on the temperature of the air around the horse. DM - You are confusing different methods of heat transfer. Heat lost by contact with the air is by convection. Heat lost from the horse to the walls (if they are cooler) is by radiation. "Draw heat" is a figure of speech. You cant take it out of the context and claim its wrong. Well you clearly can and have.

Now consider the horse standing in a nice draught free stable, with its body heating up the air around it. The horse in the wooden stable is warming the air, and some of that warmth is escaping into the cold night air through the walls and roof of the stable. The identical horse next door is in a stone stable. That stone warmed up in the winter sunshine during the day, and is now releasing some heat into the stable. In addition, less of the heat being created by the horse is going to escape into the cold night air because a big thick bit of stone, concrete block, or brick is a better insulator than a thin piece of wood. DM - But again, you are mixing different situations to try and support your argument. Its not just about insulation. If we are talking open stables, then the air temperature is going to be largely dependent on the heat escaping through the stable door. The radiant heat loss from the horse will be greater in a stone stable than in a wooden one.

And for all those reasons, stone stables are warmer in winter to stable a horse in than wooden ones. DM - I think you'll find that thick stone is used in very hot countries to insulate against the heat outside!

As per my signature, I am happy to admit when I am wrong. But you are not right about horses living in strone stables needing more rugging than horses in wooden ones.
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DM - depends on the stable.

"
In Italy, building professionals often tell you that thick stone walls will keep you warm in winter. Our first geometra said so. And recently my friend’s architect told him it wasn’t worth adding insulation to his walls since they were porous tufa stone, which the architect claimed was a good insulator. But it’s not true.

A good insulator has a high thermal resistance – it prevents heat from flowing from the warm side to the cool side. Polystyrene, rockwool, and sheep’s wool are all examples of good insulators. In many cases you can compensate for lower thermal resistance by increasing the thickness of material: if your insulation isn’t good, just use more of it. But with stone, the thermal resistance is so low that in order to offer a reasonable level of insulation, the walls need to be unrealistically thick.

A typical 500mm thick stone wall, for example, has the equivalent insulating value of only 15mm of rockwool. In comparison, to pass building regs a new house in the UK needs the equivalent of 150-200mm of rockwool. The typical stone wall lets out about fourteen times as much heat as a wall in a new house. To meet UK building regs you’d have to make it seven meters thick.

A 500mm wall of porous tufa stone is a bit better with a thermal resistance equivalent of 40mm of rockwool. Medium weight masonry is about the same. But you’d still need a wall two and a half meters thick to achieve a good level of insulation." https://carbonlimited.co.uk/2007/03/05/the-myth-of-stone-walls-as-insulation/
 
An observation from a non-scientist here, who lives in a stone house and whose ponies have a stone stable: the temperatures inside depend greatly on the weather outside.
Wet and windy = cold indoors. Dry for a few days = warm indoors. Doesn't matter if it's winter or summer - though more noticeable in winter.


My clever ponies also 'soak up the sun' in the field on a still cold sunny winter's day but appreciate a light rug outside in storms. I think we also have to be mindful of what our horses are actually doing - the ridden pony has different musculature to the one who is not ridden by dint of his training and workload. That muscle mass needs to be carefully warmed-up and cooled down so we do use rugs at times. It's the same old same old - understand how horses work and use equipment accordingly...........
 
Dr David Marlin said:
Thank you :) The Dunning-Kruger effect is clearly alive and kicking on H&H Forum ;)
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Wow that's a little harsh!

No-one is arguing with the laws of physics. Just that when you are talking about a horse at 38 degrees, the radiant heat loss is negligible. So worrying that your horse is going to have the heat sucked out of it by cold stone walls is just not a realistic concern. Not unless it's lying on them!

Also the warmer temperatures in a stone stable are nothing to do with insulation but are to do with thermal mass. A stone stable has a far larger thermal mass than a wooden one so will cool down more slowly overnight. Equally it will warm up more slowly in the morning. This is the principle by which storage heaters work: heat up a pile of bricks overnight while electricity is cheaper and then those bricks will lose that heat slowly through the day. You don't make storage heaters out of wood.

Ycbm you don't need a thought experiement - you can run the equations to work out the radiant heat loss from a 38 degree horse to a cold stone wall. Any takers?
 
catkin said:
I think we also have to be mindful of what our horses are actually doing - the ridden pony has different musculature to the one who is not ridden by dint of his training and workload. That muscle mass needs to be carefully warmed-up and cooled down so we do use rugs at times. It's the same old same old - understand how horses work and use equipment accordingly...........
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But that requires common sense.
 
Totally agree re. harsh AE. I'm not sure why it seems impossible to have an intelligent discussion with also intelligent people on a forum instead of facebook :confused:.

ps what if they are scratching their bum on it, that is the only wall contact ours have ;), lets bring a bit of friction into the mix too eh ;)
 
Oh wow, I've just looked up the Dunning-Kruger effect. How effing patronising and superior.

In the field of psychology, the Dunning–Kruger effect is a cognitive bias in which people of low ability have illusory superiority and mistakenly assess their cognitive ability as greater than it is. The cognitive bias of illusory superiority comes from the inability of low-ability people to recognize their lack of ability. Without the self-awareness of metacognition, low-ability people cannot objectively evaluate their actual competence or incompetence.[1]
 
Ambers Echo said:
Wow that's a little harsh!

No-one is arguing with the laws of physics. Just that when you are talking about a horse at 38 degrees, the radiant heat loss is negligible. So worrying that your horse is going to have the heat sucked out of it by cold stone walls is just not a realistic concern. Not unless it's lying on them!

Also the warmer temperatures in a stone stable are nothing to do with insulation but are to do with thermal mass. A stone stable has a far larger thermal mass than a wooden one so will cool down more slowly overnight. Equally it will warm up more slowly in the morning. This is the principle by which storage heaters work: heat up a pile of bricks overnight while electricity is cheaper and then those bricks will lose that heat slowly through the day. You don't make storage heaters out of wood.

Ycbm you don't need a thought experiement - you can run the equations to work out the radiant heat loss from a 38 degree horse to a cold stone wall. Any takers?
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Dunning Kruger effect comment was not directed at the majority of people. Just one person.
For a horse at 38°C and a stone wall of say 5°C the heat loss by radiation is not negligible. If it's lying on them then its conduction not radiation.
 
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