Last Updated: | By Sarah Braithwaite, Author & Horse Health Expert
Do you have a horse which is a good doer? Do you wonder whether to feed ad-lib hay or whether you should be restricting hay and feeding at a weight level suitable for your horse? Here Forageplus discusses the issue of whether you should give your horse access to free choice hay.
There has been discussion that the best way to feed horses is to give them either unlimited turnout on pasture or to give them the option of unlimited turnout and access to free choice hay. It is claimed that horses will regulate their own requirements, eating only as much as is necessary to maintain a normal weight.
Proponents of the ‘always ad-lib’ approach discuss the fact that without unlimited access to forage, horses will become stressed, that being deprived of food is unnatural and creates stress which causes cortisol release. Cortisol is a hormone which will worsen or perpetuate insulin resistance and it is claimed that this stress and the raise in this hormone will lead to acute and chronic laminitis.
Whilst it might be true that hormonal imbalance can be the cause of insulin resistance and laminitis, the amount of hay which might need to be fed to a horse and how much turn out eating grass they need, to maintain a healthy weight, is not as simple as giving them carte blanche to have an all they can eat buffet.
Firstly understand that hay and grass or just hay should be the greatest proportion of the horse’s diet. This forage supplies the greatest amount of nutrients; calories, protein, minerals and vitamins. It is an oversimplification to say that all horses regardless of work level and breed should have as much hay or grass to eat as they wish.
Some horses, like Highlands and Connemaras are genetically programmed to survive on what seems like fresh air. This is an evolutionary advantage where scarce food in winter meant that those horses which could pile the most weight on through the summer months would be more likely to survive through to the next spring. If these horses are given a high energy hay or allowed to eat as much spring time grass as they wish then many owners find that they rapidly increase their weight.Ad-lib hay for horses, is it always best for those who are good doers?Click To Tweet
Secondly understand that not all grass and hay are created equal. Spring grass will have a much higher calorific value per mouthful than the same height winter grass. Rye grass, created for the greatest milk and meat yield in farm animals will have more calories per mouthful than a multi-species meadow grass.
Hay cut in June is likely to be of a high feed value than that cut in July or August. Hay cut first thing in the morning is likely to contain more energy value than that cut in the afternoon. Even whether it is cloudy or sunny can have an impact on how many calories the leaf will contain.
The feed value of hay and grass is determined not just by the fermentable, digestible energy value of the forage but also by the amount of sugar and starch it contains. Where a horse is a good doer and genetically predisposed to insulin resistance (most native horses, Arabs, Morgans etc) the amount of sugar and starch the hay or grass contains will determine whether it is suitable for an IR horse to eat. Just eating as much as they want or need of this type of grass or hay could be unsafe in any amount. Whether fed in limited amounts or free choice, levels of sugar and starch will determine the insulin response. If the sugar and starch is too high then this will spike insulin. A horse with IR which has insulin levels constantly spiked is a horse which will gain weight because this spiking will trigger increasing obesity and insulin resistance.
While obesity per se does not cause insulin resistance, it does worsen it. This is why an overweight IR horse which loses weight slowly will improve with weight loss. However the ‘diet’ should be one which is not severe in calorie restriction as this can worsen laminitis. Recommendations by anyone to feed less than 1.5% of body weight should be politely ignored because weight loss which occurs too quickly can create metabolic stress which actually triggers or worsens IR. However feeding ad-lib hay will not work either because horses which are insulin resistant are also resistant to another hormone called leptin.
Leptin is what we at Forageplus like to call ‘the stop eating stupid hormone’ because leptin is a hormone that shuts off appetite when sufficient energy/calories have been consumed. A horse which is prone to insulin resistance loses this regulation so faced with unlimited hay the IR horse will keep munching without the shut off system to stop them becoming obese.
Then there is protein. Protein is fundamental to life; without protein there is no life, no cellular activity, no hormonal activity, no repair, no growth, no enzymatic processes to keep the body functioning. The body and brain work together to tell the horse to eat more if not enough protein has been obtained. Lack of protein means a larger appetite. Enough protein means the horse feels full and satisfied.
So we would like to suggest, VERY strongly that a blanket approach which advises ad-lib hay to all horses in all situations is VERY dangerous advice which over simplifies what is not a simple situation. It is advice which could cause you and your horse to slide down the slippery slope to obesity and an increased chance of a life threatening bout of laminitis which may cause a hole in your heart and most certainly a hole in your bank balance.
Where ad-lib hay feeding does work well is for horses which have a normal functioning metabolic system. Most horses like this will adjust after a few days to the novelty and regulate their intake to what they need. The caveat to this is that protein should be sufficient to allow this. Where protein is too low then it may well be that horses will over eat.
So what should you do if your horse is a good doer and needs to maintain or reduce weight? Firstly if you know the energy value of your hay then you can work out exactly how much to feed each day to provide the right amount of calories to maintain the correct weight. Then if you know the protein value too, you can also work out if that amount of hay is providing enough protein so that you can add an additional protein source so the horse does not over eat in an attempt to fore fill demand for this nutrient. Lastly if your horse is IR or laminits prone then knowing the sugar and starch level in the hay will determine if it is suitable and safe for your horse. Nutritional analysis will supply you with all these figures.Learn about the best method to reduce the weight of your laminitis prone horseClick To Tweet
Where you don’t know the energy value of the hay because you can’t carry out analysis then to maintain weight you can use 2% of body weight. This would mean that a horse weighing 500 kg would eat 10 kg of hay per day. Where you want slow weight loss use 1.5% of body weight or 2% of the weight you want the horse to end up weighing or which ever is the greater. This would mean that a horse weighing 500 kg would need 7.5 kg per hay per day. Where a horse is 500kg but you want it to loose weight to reach 450 kg then 2% of this weight would be 9kg. Often it is better to use 2% of the bodyweight you want the horse to reach rather than 1.5% of bodyweight so that a horse has the maximum amount of food whilst still losing weight slowly. We suggest weigh taping a horse each week to check weight loss and weighing hay using a scales used for weighing luggage.
Where hay is restricted, the amount being fed running out too quickly can become a problem so using small holed hay nets or slow feeder systems/nets is a solution. Sometimes double or even triple netting the hay is needed and this doesn’t need to be costly if you use cheap haylage nets. Alternatively, the horse can be fed multiple small meals throughout the day.
If your horse is laminitic or has been prone to laminitis it is extremely important to understand that weight control through calorie restriction will be inevitable if you are to stop the laminitis events in their track. A horse which is at the correct weight, eating the correct amount of minerals, vitamins and protein will be able to exercise and will be become healthier. Management of these horses is the key and a way of life where eating is controlled to provide optimum calories, optimum protein and optimum minerals and vitamins will put your horse in a win, win situation.
Part of this control will be making sure that your IR or laminitic horse is fed a hay with no more than 10% ESC (simple sugars) and starch, combined, fed at 1.5% of current weight or 2% of ideal weight, whichever is larger to give the most fibre feed in the diet.
Grazing on pasture should be strictly controlled. For some horses no pasture ever will be the rule. For others turn out when sugars are low, early in the morning, for limited periods of time or only at night will work. In the UK many horses are best kept off grazing in what here at Forageplus we call the rocket fuel months of April, May and June. This is when the grass is at its fastest growth and highest calorie content so it makes sense to limit exposure to this forage.
If your horse is not IR, in regular exercise and the grazing is healthy then most will be fine on grazing either 24 hours per day or for 12 hours. Many people prefer to turn out at night once the hotter days come, this is useful because not only does it help exposure to flies but it also results in horses grazing on pasture when the sugars are at their lowest.
So should you feed your horse ad-lib hay or grass? The answer is it depends and that analysis of your forage will allow you to accurately determine how best to manage feeding. Calorie restriction may be essential for native, good doer types but this will be a positive approach where protein, mineral and vitamin levels are addressed. As long as you keep to a trickle feeding approach where no less than 1.5% of body weight is fed in hay and affect slow weight loss or maintenance of the correct weight then you won’t need to worry about digestive health and with time and exercise a mineral balanced feeding approach will return your horse to metabolic health.