Manitoba Horse Hay: Nutrition and Feeding FAQs

1. What factors affect the nutrient requirements of horses?
2. How do you assess body condition in horses?
3. What is the most common sign of energy deficiency or energy excess in the horse?
4. What class of horse has the highest energy and protein requirements?
5. Do performance horses need lots of protein?
6. Do pregnant mares need a more nutritious diet?
7. Do lactating (milking mares) need a more nutritious diet?
8. What is the recommended minimum data needed from a feed analysis?
9. Do grains or hays provide enough fat to meet a horse’s fat needs?
10. I have heard that there is something in oats hay that is toxic to horses?
11. Sometimes it seems like my horse has a bottomless pit when it comes to food. How much can a horse really eat?
12. Why does my horse chew wood when he is fed a balanced, pelleted diet?
13. What do the nutritionists mean when they talk about 1:1 or 2:1 minerals?
14. What kind of mineral should I feed my horse if I am feeding it alfalfa hay? What if it is fed timothy hay?
15. Does my horse need grain?
16. What is the calcium to phosphorus (Ca:P) ratio and why is an acceptable ratio so important to horses?
17. Do horses have preferences for different hays?
18. Why is it important to feed hay to horses?
19. What characteristics do hays possess relative to other feeds?
20. Does alfalfa cause bloat in horses?
21. Does alfalfa hay harm the kidney or cause any other problems?
22. What information do you need to provide your nutritionist or veterinarian to assess your horse’s feeding program?
23. How do I assess the quality of hay?
24. How do I collect a forage sample for quality testing?
25. What is the nutritional value of beet pulp?
26. How important is the color of hay?
27. What if the hay I purchased is slightly dusty; can I feed this hay to my horse?
28. How should I store hay to prevent dust and molds?
29. How should salt be fed?
30. How much alfalfa should be in the horse’s diet?
31. What is the best kind of oil to use as an energy source?
32. Why is there so much talk about dusty hays with horses, we have cattle and never worry about it?
33. Do I need to supplement my horse with pellets or other feed products?
34. I've heard that rice bran is very good for horses; what kind of horses should I feed it to?
35. Can I feed barley or corn in place of oats?
36. What is the nutritional value of bran?

1. What factors affect the nutrient requirements of horses? Answer: Body weight and body condition (thin, fat) Age (growing vs non-growing ) Climate Type of activity (work - light, moderate, hard, strenuous) Health Temperament (breed e.g. light vs heavy) Pregnancy/lactation

2. How do you assess body condition in horses? Answer: In North America, the Henneke 9-point condition scoring system is used. In Europe and Australia, typically a 5-point system developed by Huntington is used. Usually half-points are also used in the Australian system so basically the scoring systems are both 9-point systems.

Henneke System 9-point Scoring System

3. What is the most common sign of energy deficiency or energy excess in the horse? Answer: Energy intake is calorie intake. Horses that are energy (calorie) deficient lose weight. Thin horses are often underfed horses but poor teeth and old age can contribute to thinness as well. Horses that consume too much energy are overly fat.

4. What class of horse has the highest energy and protein requirements? Answer: Newborn foals have the highest nutrient requirements.

5. Do performance horses need lots of protein? Answer: Athletic activity by the horse requires energy (calories) not protein. That is why athletic horses are fed higher amounts of grain (carbohydrates). Endurance horses can also be given supplemental energy by adding fat to the diet. Some commercial diets contain up to 15% added fat.

6. Do pregnant mares need a more nutritious diet? Answer: Yes, but not all the way through pregnancy. A mare has an 11-month gestation period. The equine fetus (the foal in the uterus) is very small until late pregnancy (9^th month). During the last 3 months of pregnancy, the mare will need to increase her energy, protein, calcium and phosphorus requirements by 10% to 20%. A mare in good body condition in early pregnancy needs no more feed than you would give a non-pregnant horse. Most pregnant mares in early pregnancy will thrive on average quality hay fed free-choice. Most do not need supplemental grain. Provide water, salt and an appropriate mineral mix.

7. Do lactating (milking mares) need a more nutritious diet? Answer: Yes. A lactating mare needs nearly double the energy, protein and mineral requirements needed by a mare in early pregnancy. A 500 kg (1100 lb) mare will produce about 15 kg or about 15 L (3 gallons) of milk per day. Making milk is a nutrient costly process. Milking mares need lush nutrient-rich pasture or good quality hay with supplemental grain to sustain milk production.

8. What is the recommended minimum data needed from a feed analysis? Answer: Moisture, crude protein, calcium, phosphorus, and estimate of energy content are the minimum analyses needed. Analysis of copper and zinc is also important in Western Canada where values are often deficient or marginal.

9. Do grains or hays provide enough fat to meet a horse’s fat needs? Answer: Hays and grains have very little fat but it is sufficient to meet a horse’s fat needs. The average fat content is about 3 to 5%. Grains have more fat than hays. Adding extra fat (1 – 2 ounces of vegetable oil per day) to a horse’s diet may add "bloom" but so will routine grooming.

10. I have heard that there is something in oats hay that is toxic to horses? Answer: The most common cereal hay used for horses is oats hay (also known as greenfeed). Nitrate can be very high in some oats hays. High nitrate can be toxic to horses. Cattle are more susceptible to nitrate poisoning than horses however; precautions should be taken whenever a hay has more than 0.5% nitrate. To be safe, pregnant mares and young horses should not be fed nitrate- containing cereal hays. Oat hay can be tested for nitrate levels at a forage and soil testing laboratory.

11. Sometimes it seems like my horse has a bottomless pit when it comes to food. How much can a horse really eat? Answer: A guideline number is that a horse will eat 1.5 to 3.5% of its body weight. What does that mean? For every 100 lbs of the horse’s weight, it will eat 1.5 to 3.5 lbs of the food. A 1000-lb horse will eat 15 to 35 lbs of feed per day. The voluntary intake (i.e. the amount of food a horse chooses to eat) depends on the palatability, the density and the processing of the food. Tasty, palatable feeds will be eaten in much higher amounts than less palatable or spoiled feeds. For example, horses will eat about 2.5 lbs of alfalfa for every 100 lbs of body weight but will only eat 1.8 lbs of mature slough hay for every 100 lbs of body weight. Horses eat more pellets than long hay.

12. Why does my horse chew wood when he is fed a balanced, pelleted diet? Answer: It used to be claimed that wood-chewing occurred because of a nutrient deficiency. However, this is seldom the case. Wood-chewing is often seen in young horses and in horses fed all-pelleted diets. This does not mean pellets are harmful. It only means long hay has to be fed with the pellets to provide fibre and to prevent boredom. In young horses, wood-chewing can be associated with tooth eruption. Horses fed an all-pellet diet, even if the diet meets all of their nutrient needs, will chew on planks, the manger etc because they are bored. Horses can eat the same weight of pellets 10 times faster than they can eat long hay. Horses fed hay spend 7 to 10 hrs per day eating. Horses fed the same weight of pellets eat them in less than an hour. So, on an all-pellet diet, horses have to do something to occupy the empty hours. If wood is all they have to chew on, that’s what they do.

13. What do the nutritionists mean when they talk about 1:1 or 2:1 minerals? Answer: Usually minerals are described as 1:1, 2:1, or 3:1. The numbers are the ratio of calcium to phosphorus in the product. The absolute amount of calcium and phosphorus can differ among products. For example a 2:1 mineral could be 14% calcium and 7% phosphorus or 20% calcium and 10% phosphorus. However, if you need to add a lot of calcium you should choose a mineral product with a higher calcium number e.g. the 20% product. Your horse specialist or nutritionist can tell you which product to use.

14. What kind of mineral should I feed my horse if I am feeding it alfalfa hay? What if it is fed timothy hay? Answer: The kind of mineral your horse needs depends on its diet. Alfalfa hay is high in calcium. Horses fed alfalfa or any legume hay typically need a mineral that does not add much calcium. Use a 1:1 mineral (1 part calcium to 1 part phosphorus) with trace minerals and vitamins. Calcium-free minerals are available but are not usually recommended for horses. Grass hays are lower in calcium than legumes. Horses fed a grass hay diet usually need a mineral that is 2:1 in calcium and phosphorus. Grain has very little calcium. Therefore, horses fed a high grain diet with a grass hay may need to be fed a 3:1 mineral.

15. Does my horse need grain? Answer: Horses are herbivores, that is, they are forage eaters. So feed more, rather than less, hay. Grain is not a compulsory feed for a horse. Grain is only needed for horses that have a high energy requirement e.g. racehorses etc.

16. What is the calcium:phosphorus ratio and why is an acceptable ratio so important to horses? Answer: The calcium:phosphorus ratio is the amount of calcium relative to phosphorus in the diet. For example, a grass hay might contain 0.4% calcium and 0.15% phosphorus. The calcium:phosphorus ratio is 2.6:1. The reason the ratio is important is that calcium and phosphorus are laid down in bone in approximately a 2:1 ratio. That is why many nutritionists recommend a 2:1 calcium to phosphorus ratio in a horse’s diet. However, we know that mature horses can tolerate a wide range of calcium:phosphorus (1:1 to 8:1) with no clinical problems. Young horses should have a narrower range e.g. (1.5:1 to 3:1) because their bones are actively growing. Not only is the ratio important, it is also important that the diet has enough calcium and enough phosphorus. For example, a foal’s diet should have 0.7% calcium in the diet and 0.4% phosphorus. If using the grass hay from above, its ratio is okay but there is not enough of either mineral to meet the growing needs of the foal.

17. Do horses have preferences for different hays? Answer: Yes. Horses do have some preferences for hays. Studies have shown that horses prefer brome, timothy and alfalfa to perennial ryegrass or fescue. Also, some horses even prefer leaves to stems of alfalfa hay or vice versa. Horses will choose a hay that they like the most but it doesn’t mean that other hays that they consume at a slower rate aren’t just as suitable. You need to find the balance between hay they reject and hay that they consume it too rapidly.

18. Why is it important to feed hay to horses? Answer: Hays provide important nutrients but also bulk to maintain the muscle tone and activity of the intestinal tract. Horses that do not get enough bulk can develop clinical problems including colic, founder, wood chewing and other vices.

19. What characteristics do hays possess relative to other feeds? Answer: Hays are bulky, high in fiber, modest in energy content, higher in calcium than phosphorus, high in potassium, high in vitamins A, E and K. If hay is sun-cured it is higher in vitamin D than grains. Protein content depends on the type of hay and when it is harvested. Alfalfa hay is typically high in protein and calcium. Timothy and brome hays are usually lower in protein and lower in calcium content.

20. Does alfalfa cause bloat in horses? Answer: Horses rarely, if ever, bloat on either alfalfa pastures or hays. However, precautions should be used when grazing horses prone to founder (laminitis) on new alfalfa pastures. These types of horses may get a recurrence of laminitis on lush alfalfa. When changing a horses diet whether on to pasture or a different hay it should always be done over a number of days.

21. Does alfalfa hay harm the kidney or cause any other problems? Answer: Alfalfa hay has a high protein and calcium content but feeding it does not harm horses with normal kidneys. Because of its high protein content, when alfalfa is fed to mature horses, the stall may smell strongly of ammonia. The ammonia is the extra protein that the horse did not need and which it had to get rid of in the urine. The other characteristic of the urine of horse being fed alfalfa is a reddy-whitish color. This is the extra calcium that is being voided. Other biases against alfalfa are that it is dusty, mouldy and causes colic. These conditions can occur with any feed that is poorly cured or carbohydrate rich. However, alfalfa is a nutrient rich feed and is the hay of choice for young growing horses and lactating mares.

22. What information do you need to provide your nutritionist or veterinarian to assess your horse’s feeding program? Answer: You need to provide the horse’s body weight (use a girth tape), age, breed, management (housed outdoors or indoors), feeding system (individual vs group), types of feeds given, approximate amounts, function of the horse (couch potato or athlete), water source and feed analysis if available.

23. How do I assess the quality of hay? Answer: To be suitable hay for horses it must be mold and dust free, green, leafy and fresh smelling. Break open a bale and look it over for greenness and evidence of molds, weeds and foreign objects. Next smell the bale, it should smell fresh not musty, sour or moldy and finally give it a good shake to see if fine dust comes out of the bale. After hay has met these criteria then it must be tested at a lab to determine the actual nutrient content. Ask for a wet chemistry test, this will give you the most accurate analysis for mineral content. Many of the larger hay producers will provide this analysis when you purchase their hay. Just ask.

24. How do I collect a forage sample for quality testing? Answer: Bale core samplers can be borrowed from local Ag Rep offices. These probes are pushed into the bale to extract a core sample. You need to take random samples from at least 15 to 20 bales. The more samples you take the more accurate representation you will get from your analysis. Remember to sample different lots or types of hays separately e.g. alfalfa from grass hay.

25. What is the nutritional value of beet pulp? Answer: Beet pulp has a lower energy and similar protein content (9%) to oats except that it has a much higher fiber content and costs more. Beet pulp is low in phosphorus, selenium, vitamin A, vitamin D and several B-vitamins so high amounts should never be fed to horses without appropriate supplementation. There is considerable dispute whether beet pulp should be fed wet or dry. Molasses is often added to beet pulp to increase its palatability. Once a taste for beet pulp is acquired, horses do appear to like it so it is a good carrier to increase intakes of less palatable feeds or mineral-vitamin supplements.

26. How important is the color of hay? Answer: Hay should be green colored but it should not be your only guide for determining hay quality. Different forages such as smooth brome, alfalfa or timothy, for example, will all cure a different color of green. As well, some hays will appear a good green color but will exhibit mold dust when shaken and a musty or sour smell. Any hay with these properties is unacceptable as horse hay. Use color as only one of the criteria to determine if hay is suitable as horse feed.

27. What if the hay I purchased is slightly dusty; can I feed this hay to my horse? Answer: Yes. The best way to use this type of hay is to soak it in water for 10 to 30 minutes before feeding. If feeding outdoors give the hay a good shaking.

28. How should I store hay to prevent dust and molds? Answer: It is important to understand that molds develop for a number of reasons. Hays that are put up too moist or not properly cured before baling will experience some mold growth. Hay can also mold due to moisture wicking from the ground up into the bale or from moisture seeping into the bale. Storage systems should be placed on high ground with good drainage. If possible wooden palettes place on the ground will stop a lot of the losses from moisture wicking into the bale. As a cover tarps or a shed can be used. If using a tarp place a line of bales to create a peak to help shed rain and snow as well as allowing air circulation.

29. How should salt be fed? Answer: Either salt blocks or loose salt can be fed to horses. Typically, horses should be provided with a mineral mix with 25% salt and a salt block/loose salt as well. Loose salt may be fed in the winter if outdoor horses seem to stop using the salt block.

30. How much alfalfa should be in the horse’s diet? Answer: The amount of alfalfa in the diet isn’t as important of a question as is the quality of the hay. Without a feed analysis you can only guess. Early cut grass hay may have more energy and protein than a late cut of very stemmy alfalfa. Alfalfa when cut at an earlier stage of growth generally has more protein, energy and nutrients so it is a good choice for horses with high nutritional needs i.e. lactating mares and growing foals. If your horse does not have high nutritional need i.e. idle mature horse, then the diet may not need any alfalfa. Try to pick forage that meets your horse’s nutritional requirements, not necessarily exceeds their needs, regardless of the forage variety.

31. What is the best kind of oil to use as an energy source? Answer: Any kind of vegetable oil will do. Buy the cheapest you can find in your area. Across the prairies canola oil is very popular but in the corn growing belts in Canada and US corn oil may be the best choice. Soybean oil and rice bran oil has also been used with success but are more costly.

32. Why is there so much talk about dusty hays with horses, we have cattle and never worry about it? Answer: First of all dust in hay almost always comes from the spores of molds. These dusts inflame the respiratory tract and impair breathing. With repeated exposure some horses will develop permanent lung damage which will impair their performance at work and in extreme cases even at rest. Dust and mould in the horse causes the disease known commonly as heaves (or medically as chronic obstructive pulmonary disease or COPD). Cattle do get a form of "heaves" but not as a result of mould or dust allergens as seen in the horse. In the horse, heaves is considered to be a management disease caused by the use of poor quality hay often fed in poorly ventilated barns.

33. Do I need to supplement my horse with pellets or other feed products? Answer: It depends. If you own only a few horses it may not be practical to purchase a number of different kinds of hay. Feed products may be the easiest way to meet the different nutritional requirements of your horses. Example: You have purchased hay that is perfect for your mature horse but not adequate in protein and energy for your yearling. A feed product may be the most practical way to boost the ration for your yearling.

34. I’ve heard that rice bran is very good for horses; what kind of horses should I feed it to? Answer: Rice bran that is fed to horses is the rice hull leftover after processing rice. It contains about 13 – 14% protein and 18 – 20% fat. The fat component is the reason rice bran has become a popular feed. The fat contributes energy to the horse’s diet. Rice bran has also some components that have taken on "mythical" properties. Two of these are tocotrienol and gamma oryzanol. Tocotrienol is a form of vitamin E that may be a useful antioxidant. Gamma oryzanol is a substance whose actions are not clearly identified. It is a substance that is purported to "help build muscle" but is also felt to cause ulcers in young horses. Rice bran diets were initially designed to "treat" horses with polysaccharide storage myopathy (seen in some lines of QH, Belgians, Thoroughbreds, Percherons etc) who cannot metabolize carbohydrates. These horses must be fed a high fat diet. Latterly, rice bran has developed a following by many owners of athletic horses. However, the benefits of high fat diets depend entirely on the type of activity. High fat diets are useful for long-duration, endurance activity but makes no metabolic sense for horses in short duration, high intensity activity.

35. Can I feed barley or corn in place of oats? Answer: Barley and corn can be fed to horses. In many countries, barley and corn are grains of choice because oats is not readily available or is too expensive. Barley and corn are more dense (weigh more per quart) than oats and as result contain more calories per quart. Barley and corn must be fed by weight not volume because barley weighs about 1.5 times and corn 1.8 times as much as oats for the same volume. Barley is between corn and oats in energy, fiber and protein content. Corn is lower in protein (9 - 10%) than both barley and oats and should not be used for growing horses. Barley and corn are much easier to overfeed so making a mistake in feeding can more easily result in founder. Poor-quality corn may also contain mold or fungal toxins that can be dangerous to the horse. Barley is hard – rolling makes it more palatable to horses. Corn can be fed whole, cracked or on the ear.

36. What is the nutritional value of bran? Answer: Bran is high in fiber but other nutritional properties are exceptionally low. As a fiber source it is expensive. Hay would be a better source of fiber as it makes up the better part of a horse’s ration and contains many important nutrients.