Feeding and Care of the Horse

Lon D. Lewis

• Publisher: Wiley-Blackwell
• Year: 2013
• ISBN:
  9781118695043
• Edition: 2
• Topic: Medicine
• Subtopic: Equine Veterinary Science

This is the concise, easy-to-use version of Dr. Lewis's Equine Clinical Nutrition, Feeding and Care. It includes a full-color section identifying toxic plants and provides practical information on the diversified effects of different nutrients, feeds and supplements on a horse's athletic performance, reproduction, growth, hooves, appetite, behavior and disease. The book can help prevent common, but expensive problems in horses of all ages.

Section Two

FEEDING AND CARE OF HORSES

Chapter 8

GENERAL HORSE FEEDING PRACTICES

Water Feeding

Forage Feeding

Forage Necessity

Methods of Feeding Harvested Forages

Grain Feeding

Grain Necessity

Methods of Feeding Grain

Feeding Frequency

Monitoring Horses’ Nutritional and Health Status

Group Socialization, Communication, and Feeding

Changing Diets

WATER FEEDING

Before and during prolonged exercise, the horse should be allowed and encouraged to consume as much water as it will drink. However, following exercise, the horse should be cooled down before being allowed to drink as much as it wants. Consumption of a sufficient amount of water by the hot horse after physical exertion may cause colic and acute laminitis or founder. However, at all other times adequate quantities of good-quality palatable water should be readily available. Whether the horse drinks before or after feeding does not affect feed digestibility, but it does affect feed intake. Thirsty horses will reduce their feed intake, or not eat at all, if water isn’t available before or during feeding.

FORAGE FEEDING

Forage Necessity

Water and forage are the two feeds required for life by all horses in all situations. Other feeds such as grain various supplements, and salt are not needed by many classes of horses and in many situations, or are optional—i.e., they may be beneficial but they are not required. Horses should be allowed all of both the water and forage that they will consume without waste. An exception is the overweight horse, in which forage intake should be restricted and no grain fed.

Forage is required in the horse’s diet as a source of fiber. Usable or digestible fiber is necessary as a source of energy by microorganisms in the horse’s cecum and large intestine, and, although not required, does provide a source of dietary energy for the horse. However, indigestible fiber, which is low in all nonforage feeds (except for some by-product feeds) is required for the maintenance of normal gastrointestinal pH, motility, and function. Indigestible fiber also helps prevent too rapid an intake of readily digested carbohydrates, which are high in cereal grains. Too rapid an intake of an excess amount of readily digested carbohydrates will cause diarrhea, colic, and acute laminitis or founder. Thus, an adequate amount of fiber, which can be provided only by feeding sufficient forage or some by-products such as hulls, are required by the horse for normal intestinal function and by microbial organisms, both of which are necessary for the horse’s health and well-being.

Horses have been maintained in good health by feeding as little as 0.5 lbs of forage/100 lbs body weight daily (0.5 kgs/100 kg), with the remainder of their dietary energy needs provided by grain. This low amount of forage results in a diet consisting of 15 to 35% forage and 65 to 85% grain, and puts the horse at risk of the problems caused by inadequate fiber intake. If at any time, for any reason (such as not feeling well, weather or environmental change, etc.), the horse eats less feed, the reduction will generally be in the amount of forage and not the amount of grain eaten, resulting in an even lower fiber intake, which may be sufficient to cause diarrhea, colic, or acute laminitis. In addition, the high grain intake increases the risk of exertion myopathy (see Chapter 11) and, over time, obesity due to excess energy intake. For these reasons it is recommended that forage make up at least one-half of the total weight of feed dry matter consumed, or at least 1 lb of forage dry matter/100 lbs body weight daily (1 kg/ 100 kg) be consumed. If less forage than this is consumed, either as determined by actual measurement or by calculating the amount of forage that the horse needs to consume to provide its dietary energy needs above that provided by the amount of grain fed (for a description of how to determine this, see the section on “Determining the Total Amount of Feed Needed by the Horse,” in Chapter 6), the amount of grain fed should be reduced.

Feeding inadequate forage to the horse not on pasture greatly increases the risk of not only diarrhea, colic, and founder, but also eating wood, feces, and, particularly in young horses, tail chewing and, less commonly, mane chewing. Increased wood chewing with decreased forage intake is known to occur for two reasons: (1) decreased eating time, resulting in increased boredom, and (2) increased gut acid. Wood chewing is detrimental for at least three reasons: (1) damage to facilities, (2) occasionally wood splinters in the oral cavity, and (3) intestinal obstruction, which if untreated may be fatal. Tail and mane chewing are not only cosmetic problems but may also cause intestinal obstruction. Although there are other causes of wood chewing, eating feces, and tail and/or mane chewing than boredom and inadequate forage in the diet (such as mineral and protein deficiencies, play, and mimicking other horses), these are the most common causes, and alleviating them is the most commonly successful means of stopping or preventing these behavioral problems.

Methods of Feeding Harvested Forages

Forage should be fed in a manner that minimizes: (1) forage losses, particularly of leaves, which are the component highest in nutritional value; (2) forage fecal contamination, which not only increases forage losses but increases intestinal parasitism; and (3) dust inhalation, during their consumption, which increases respiratory problems. To accomplish these objectives, harvested forages should be fed in a container or rack that catches leaves and loose forage, and that keeps as much forage as possible off the ground. There are numerous types of hay racks, feed troughs, or feed bunks that may be used, as shown in Figure 8–1.

Feed losses are considerably higher when the feed is consumed from the ground instead of from a feeder. Even when ground conditions are ideal (firm and dry), feeding hay on the ground can decrease growth rate and feed efficiency nearly 20% below that with the same amount of the same hay in a feeder. Feed losses are greater when hay is fed on the ground because of: (1) a greater loss of the hay, particularly leaves, and (2) greater fecal and urine contamination of the hay, resulting in feed the horses won’t eat. If they do eat fecally contaminated hay, it increases the risk of intestinal parasite egg intake and, therefore, intestinal parasitism and all the detrimental effects this causes (as described in Chapter 9). Stalled horses defecate an average of once every 1.5 hrs and, even if adequate space is available, walk away from their feeding area before defecating less than one-half of the time. Thus, horses defecate and urinate frequently while eating, and the majority of the time do so in their feeding area, contaminating feed that is on the ground. However, even when hay is placed in a feed bunk, most horses will pull much of it out of the bunk and eat it from the ground. This may occur because of their desire to see better what is going on around them while eating. This is an understandable desire: they can better avoid being hurt by other horses wanting their feed; it is also a residual antipredator behavior. When the hay is eaten from a feed bunk, the horse will lift its head frequently (in one study 25 times/hr) so they can be more aware of what is happening around them.

Fig. 8-1. Three types of feeders for horses for use in stables, paddocks, or pasture. Hay rack-type feeders (A and B) allow the horse to see while eating; catch leaves and loose hay, thereby minimizing their loss; minimize dust inhalation; and can be used for feeding grain as well as hay. Tire hay feeders (C) may be made by removing most of the sides of all except the bottom side of the bottom tire, on which a solid but not water-tight platform may be attached, and fastening the tires together. Hay losses may be greater for this type of feeder, and for feed troughs or bunks, than for hay rack-type feeders because many horses pull much of the hay out of them so they can see while eating it. Tire feeders and feed troughs would also be expected to result in greater dust inhalation.

Hay consumption from a feed bunk or from a feeder placed above the horse’s shoulder increases material getting into their eyes and dust inhalation while eating, which in turn increases the risk and occurrence of respiratory problems such as coughing, emphysema, heaves, exercise-induced pulmonary hemorrhage, and probably susceptibility to infectious respiratory diseases. For these and the reasons described above, it is recommended that all harvested forage be fed from hay racks designed to catch falling leaves and loose hay (Fig. 8–1 A and B), and that they not be higher than the horse’s shoulder level.

GRAIN FEEDING

Grain Necessity

No grain or concentrates are needed by many horses all or the majority of the time. Grain or grain mixes are fed:

1. When necessary to provide the nutrients needed but not provided in adequate amounts by the forage consumed (most often this is during growth, lactation, and intense training or use).

2. When good-quality forages are poorly available or more expensive than grain (see Example 6, Chapter 7).

3. When desired for other reasons, such as a treat, training or behavior modification aid, to help get horses in or to catch them, etc.

Although horses may be gradually adapted to a diet consisting entirely of cereal grain, the greater the proportion of grain in the diet, the greater the risk of diarrhea, colic, acute laminitis or founder, exertion myopathy, hyperactivity, and obesity. For these reasons it is recommended that a grain or concentrate mix not make up over one-half of the total amount of feed of similar moisture content consumed, except for horses less than 1 year of age or those being used intensely for sprint-type activity in which up to 70% grain mix may be fed (Appendix Table 1). However, even for these horses, a maximum of 50% grain mix in the diet is safer. This would be a maximum of 0.7 lbs/100 lbs body wt (0.7 kg/100 kg) daily.

Methods of Feeding Grain

Grain and forages are generally fed at the same time. Because cereal grains are more palatable, most horses will eat all of the grain before eating any of the forage. Some believe that feeding grain after most of the forage has been consumed is beneficial because it will result in a slower rate of grain consumption. This doesn’t appear to occur, however. The rate of grain consumption, as well as chewing behavior, also appears to be unaffected by the fiber content of the grain.

In addition, forage consumed with grain decreases the amount of the grain’s starch digested in the small intestine and, therefore, increases the amount that reaches the cecum (Fig. 1–1). Excess starch in the cecum causes cecal acidosis, which if sufficiently severe results in diarrhea, colic or founder. The risk of this is decreased by not feeding forage for one hour or more before and for 3 or more hours after feeding grain. However, this risk can be better minimized in most feeding programs by feeding less grain. Not feeding forage and grain at the same time, increases feeding time and labor, and may not be practical in some situations. In addition, grain consumption before forage, as occurs when both are fed at the same time, results in a more intense mixing of ingesta and less variation in the concentration of substances in the horse’s large intestine.

Grains, like harvested forages, should be fed in a feeder to decrease feed losses and dirt consumption, which, if sufficient over time, may result in sand-induced colic, and/ or, intestinal impaction. Wooden, plastic, or rubber feeding pans may be used for nonstabled horses (Fig. 8–2) or feed bags may be used (Fig. 8–3A, B). To prevent injury, metal feed pans are not recommended. Lipped feeding pans, and troughs with rings mounted on top, will help prevent horses from rooting grain out on the ground if this is a problem with a particular horse. This is not a problem with most horses unless they are being overfed.

Many people feed by volume, i.e., by so many coffee cans, scoops, quarts or liters of grain, and by flakes of hay. There is no disadvantage in feeding by volume provided it is known what weight of feed that volume provides. The weight of feed per unit of volume, or density, varies widely, as shown in Appendix Table 8. For example, a 1 qt, 1 lb. or 1 liter (1-L) coffee can holds 0.5 lbs (0.25 kg) of bran, 0.85 to 1 lb (0.4 kg) of oats, and 1.9 lbs (0.9 kg) of wheat, which provide 0.75, 1.1, and 2.9 Mcal respectively, or nearly a fourfold difference in the amount of dietary energy provided by the same volume of feed. The small standard-size square bale may weigh anywhere from 35 to 120 lbs (16 to 55 kg), although it usually weighs 60 to 80 lbs (27 to 36 kg). A flake of it may weigh anywhere from a few to 15 lbs (1.5 to 7 kg). Thus, to determine the correct amount to feed, you should weigh the amount that the container you are using holds of the grain mix being fed, and the average size flake of the hay being fed (Fig. 8–4A, B).

Fig. 8–2. Nonstabled horses may be fed grain in wooden, plastic, or rubber feeding pans. Metal pans are not recommended as they may cause injuries.

Fig. 8–3(A, B). Feed bags work well for feeding horses in a group. Each horse is assured of receiving the correct amount of the specific grain mix fed without any being wasted. Care should be taken to ensure that the feeding bags are removed as soon as the horse finishes eating the grain.

FEEDING FREQUENCY

Horses have relatively small stomachs (Fig. 1–1) whose capacity constitutes only about 7 to 8% of that of their gastrointestinal tract, as compared to 60 to 70% for cattle.

Fig. 8–4(A,B). The correct weight of feed should be fed. To do this, weigh the amount that the container being used to feed with holds of the grain mix being fed. Any type of container may be used, such as a coffee can (A) or an ice cream bucket. A grain scoop can also be made by cutting the bottom out of a plastic jug (B).

This limits the amount that can be eaten in a single meal. A small stomach is an advantage for enhancing wild horses’ ability to flee from danger, and has no disadvantage for them since they are on pasture and able to eat small amounts continually. Horses on pasture spend 50 to 70% of their time, 24 hrs/day, grazing, during which small amounts of grass are ingested continually during the grazing periods. Regardless of the type of feed (hay, grain, or a complete pelleted feed), if it is available, most horses will eat hourly during the day and every 2 to 3 hours during the night. However, even when the feed is always available, the amount of time spent eating decreases from 50 to 70% when on pasture, to 30 to 70% when fed only hay, to 35 to 40% when fed a complete pelleted feed, and to 13 to 19% when fed a grain mix only. The decreased amount of time spent eating means more feed is consumed at one time. The amount consumed at one time is even greater when feed is not always available, as is the case and necessity for most horses not on pasture.

The greater the amount consumed at one time, the greater the stomachs distention, increase in gastrointestinal motility, and alteration it causes in the horse. However, horses can safely be fed even a high-grain diet as infrequently as twice daily when the total amount of feed is no more than the amount needed for maintenance, which would be up to 0.8 to 0.9 lb of grain/100 lbs body weight (0.8 to 0.9 kg/100 Kg) daily. However, for safety a maximum of one-half this amount of grain at a single feeding is recommended.

To prevent digestive dysfunctions (excessive gas production, colic, laminitis, and impaired fiber fermentation) grain intake in the horse fed 2 to 3 meals daily should be limited to about 0.5 lb of grain/100 lbs body weight (0.5 kg/100 kg) per feeding. When grain ingestion exceed these amounts, there is a dramatic increase in the amount of starch that escapes digestion and absorption from the small intestine, which greatly increases the risk of these problems.

Infrequent meal-induced changes in intestinal motility and blood flow increase the risk and occurrence of colic, a disease primarily of stabled or paddocked horses. This major disease of horses is uncommon in those on pasture. Since these changes, which increase the risk of colic, do not occur in response to small amounts consumed frequently, their occurrence and, therefore, the risk and occurrence of colic in horses not on pasture, can be decreased by: (1) having any forage, but preferably long-stem hay, available for the horse to eat to satiation and for as much of the time as possible; (2) feeding as frequently, at as regular, and at as even intervals as practical; and (3) feeding as little grain as necessary. Long-stem hay or pasture forage should be the basis for all feeding programs, and grain should be fed only if necessary and in as small amounts as possible. This doesn’t mean that grain shouldn’t be fed if desired or needed, but that forage should constitute the majority of the feed consumed. Two exceptions would be for the horse with poor teeth that may do better on a complete pelleted feed and/or more grain, and when good-quality forage is poorly available or considerably more expensive than grain (see Example 6 in Chapter 7).

In summary, it is recommended that all feeds be fed to all horses: (1) in equally divided amounts, (2) as near the same time each day and at as even intervals as practical, and (3) at least twice daily, but as many more times daily as practical. If the amount of grain fed is small (less than 0.25 lb/100 lbs bw daily) there may be little advantage in feeding it more than once daily. Feed working horses, lactating mares, and growing horses receiving large amounts of feed (an amount equal to more than 2.5% of their body weight daily) at least 3 times daily. It may be of benefit to feed grain to horses in intense training or use 4 to 5 hours prior to exercise, and not to feed them for at least one hour after strenuous exertion (see Chapter 11).

MONITORING HORSES’ NUTRITIONAL AND HEALTH STATUS

Regardless of the types of horses or what o...