ASC-120 C O O P E R A T I V E E X T E N S I O N S E R V I C E U N I V E R S I T Y O F K E N T U C K Y • C O L L E G E O F A G R I C U L T U R E Forages for Horses Equine Section, Department of Animal Sciences

orses are herbivores, meaning that Table 1. Effect of maturity on energy and protein value of selected Hgrasses and other types of forages hays. are natural dietary components. Digestible Crude Digestible Absence of forage in the horse’s diet Stage of Energy TDN Protein Protein can lead to digestive disorders. Basically maturity (Mcal/kg) % % % the horse has an absolute requirement Alfalfa Early bloom 2.42 55 17.2 13.4 for roughage so that its digestive tract Mid-bloom 2.29 52 16.0 11.6 will function normally. This requirement Full bloom 2.16 49 15.0 10.1 can be supplied either as pasture or Bluegrass hay. Pre-grazed 2.15 50 15.0 12.6 Forages contribute energy, protein, Post-head grazed 2.0 45 10.0 minerals and vitamins at various levels Orchardgrass 2.2 50 16.0 13.5 depending on the forage specie and quality. Stage of maturity greatly influences forage quality and availability of nutrients. Horses have limited ability Protein is another nutrient that can In addition to stage of maturity, to utilize poor quality forage, so good be supplied at adequate levels by forage leafiness, presence of foreign material, pasture management is vital if the horse if the forage is managed properly. color and the type of forage are all is going to use the forage to its utmost. Mature forages will contain lower levels indicators of quality. Mature horses doing little or no of protein and be less digestible than • Leafiness is a good indicator of qual- work can be maintained without the same forage in the early growth ity, especially in legume hays, be- supplementation on high quality stages. Research shows that horses can cause the leaf contains twice the pasture. The main reason concentrate digest about 50 to 70% of forage protein. amount of nutrients as the stem. mixes are fed to hard working and A forage’s stage of maturity, more • Freedom from weeds, mold and de- productive horses is because the horse’s than any other factor, affects how useful bris is critical to a high quality forage. digestive tract has a relatively small it is as a source of nutrients for the Horses are very susceptible to colic capacity, making it impossible for them horse. The more mature the plant and digestive disorders particularly to consume enough roughage to meet becomes, the less available the nutrients. when consuming forages containing their nutrient needs. Table 1 shows the dramatic effect that foreign material. maturity has on digestible energy and Forage Quality protein. Pasture Types and Nutrients Forages are good sources of Management Forages and grains contain much vitamins particularly vitamins A, C Type the same nutrients, but their proportions and B-complex and can supply large and availability are different. Forages amounts of minerals like calcium. The forage’s ability to meet the supply energy. One form is fiber. The horse’s nutrient needs is not only horse does not break down fibrous determined by those needs but also by Determining Quality how digestible and available the forage energy as readily as energy sources like Forage quality can be determined to starch. As a forage’s fiber content source is. In Kentucky, bluegrass and a limited extent by visual inspection, or fescue pastures dominate simply increases, the availability of energy more accurately by chemical analysis. decreases. Horses cannot utilize poor because they are best suited for the A forage’s nutrient content is determined state’s environment. quality forage as efficiently as cattle by management techniques and forage can. Bluegrass pastures provide an species. Grazing density can influence excellent source of high quality forages pasture forage quality by its influence for most classes of horses, particularly on stage of maturity and leafiness.

A G R I C U L T U R E • H O M E E C O N1 O M I C S • 4-H • D E V E L O P M E N T in the spring. Mature idle horses, barren A good fertilization program, pasture and type of operation. mares and mares in the first two-thirds pasture rotation, and light grazing of Regardless of how the forage is supplied, of gestation can meet their nutrient new pastures and of pastures early in it should be done in the most economical needs adequately on well managed the spring are other management way. So when purchasing hay, compare bluegrass pasture. practices which allow for higher quality it on a nutrient cost basis as well as a Fescue is probably the most pastures. Nitrogen fertilization (25-50 cost per weight. For example compare predominant grass used in Kentucky, lb N/acre) in early March can move the the protein cost of the following hays: because it does very well on Kentucky grazing season forward, particularly for soil. Fescue has a long, growing season grass pastures. Hay A: and will provide forage during most of Stocking rates can help maintain Cost $100/ton the year. However, endophyte infected good pastures. Obviously the stocking Contains 18% crude protein (CP) fescue should not be fed to mares in rate varies with type and class of horse, 2000 lb x .18 CP = 360 lb CP late gestation or lactation and does not specie of grasses used in pasture, season $100/360 lb CP = $0.27/lb CP adequately meet the needs of the young and soil fertility. Generally you should growing horse. allow 2 to 3 acres/horse year round to Regardless of what species of plant optimize pasture utilization while Hay B: Cost $80/ton dominates in grass pastures, the maintaining healthy pastures. Some Contains 10% CP nutritional value can be enhanced by horse operations use cattle to aid in introducing some type of legume. pasture maintenance. 2000 lb x .10 CP = 200 lb CP Mixed pastures (grass-legume $80/200 lb CP = $0.40/lb CP pastures) usually are higher in protein. Using Forages in the Diet In this example, hay A supplies Also, because the growing seasons of Horses are expected to consume protein at less expense than does hay most grasses and legumes vary, a from 2.5 to 3.0% of their body weight B. Hay B contains more fibrous material, mixture allows an extended grazing in dry matter. For example, a 1200 lb making the protein less available and season. A common practice is over mare is expected to consume 30-36 lb compounding the problem of low seeding with some type of clover, like of dry matter/day. The greater the protein. sweet, white or ladino clover. Legumes nutrient density of the feed stuff Estimating costs of supplying also reduce fertilizer costs because of consumed, the smaller the amount nutrients from hay and grain rations is their nitrogen fixing capacity. which must be consumed to meet her a little more difficult. Consider how to nutrient needs. This point further estimate cost and meet the needs of a emphasizes how important forage Management group of mares in late gestation. If the maturity is for meeting a horse’s nutrient Management practices are essential energy content of hay A were higher requirements. to maintaining a high quality pasture. than hay B, then less grain is needed Several factors affect either voluntary Plant height is critical from a with this hay. The mares require a total intake or horses’ ability to consume nutritional standpoint. As plant height ration of 12% crude protein. Therefore enough forage to meet their nutrient increases, digestibility decreases thus a 70:30 ratio of hay A:grain and a 60:40 needs. As stage of pregnancy increases, making the pasture less valuable. Also, ratio of hay B:grain can be estimated to voluntary intake of forages decreases as grass height increases the clovers meet the group’s needs. In this example and nutrient needs increase. Because and other low growing grasses are two grain rations are available, a 12% the horse at high work intensities has crowded out and weeds are more likely and a 168% crude protein. The 12% CP high nutrient needs, the mare in late to gain hold. Pastures should be mowed mix will be combined with hay A and gestation, the lactating mare and the or grazed adequately to keep grasses 3 the 16% CP mix with hay B. young, rapidly growing horse probably to 4 inches high to optimize digestibility Cost calculations: and allow for legume growth. Avoid cannot consume enough forage to meet over grazing as it can damage pasture their nutrient needs. However the Ration 1 plants and increase parasite and sand mature idle horse, horses at light work 70:30 hay to grain mix colic problems. and the pregnant mare early in gestation Contains 18% CP hay which costs Manure control can be most may meet their nutrient needs with $100/ton 12% grain mix which costs $135/ton effective via a chain harrow. Chain good quality forage alone. harrowing prevents manure build up in The cost of forage is a large part of Total ration cost = certain areas of the pasture and allows feed cost on any horse farm. Decisions (.70 x $100) + (.30 x $135) for more uniform grazing. It also exposes on how to supply that forage will Total ration cost = $110.50/ton parasites and parasite eggs to sunlight depend on many factors, such as land Total ration CP = and dryness, helping control them. availability, land that can be used as (.70 x .18) + (.30 x .12) Total ration CP = 16.2%

2 Ration 2 Toxicity Problems with Mold problems can occur in hay 60:40 hay to grain mix Forages and grains harvested in humid Contains 10% CP hay which costs environments. Be especially careful in $80/ton Horses are extremely susceptible to 16% grain mix which costs $160/ton molds, fungus and other sources of Kentucky to harvest hay correctly and toxic substances in forages. Fresh, clean without mold. Total ration cost = sources of forages are always Blister beetles contain a toxin, (.60 x $80) + (.40 x $160) "cantharidin," which causes irritation to Total ration cost = $112/ton recommended when feeding horses. Some forages have toxic effects due the digestive tract’s lining and ingestion Total ration CP = to endogenous substances. is fatal. In the past, blister beetles in (.60 x .10) + (.40 x .16) alfalfa have not been a concern to most Total ration CP = 12.4% • Sudangrasses may contain a glyco- side which can cause muscle weak- Kentucky horse producers. Recently, however, some blister beetles have Both rations meet or exceed the ness, urinary tract failure, neural de- generation and death. been found in hay imported to mares’ requirements. However by using Kentucky, Because no level of ingestion ration 1 the horseman saves $175.20/ • Fescue is another forage that could have toxic properties if contaminated is safe, proper forage management year between the two rations (based on techniques must be implemented to a 20 head mare herd consuming 32 lb by the endophyte fungus. Mares graz- ing infected fescue suffer from ensure that the hay is free of beetles. of ration/head/day). Many poisonous plants produce Hay can be fed to horses on pasture agalactia (extremely decreased milk production), prolonged gestation and toxins fatal to horses. Some common to supplement their diet. Hay plants include ornamental shrubs (yews) supplementation is usually done during tough placentas. Decrease the diet’s fescue component by feeding supple- and nightshade, but any plant known the winter months or during drought to cause problems in other species will situations. Feed hay according to the mental grain or legume hay. The safest prevention is to remove mares probably affect horses. Usually, these horse’s body condition. Horses plants are not palatable and horses will maintained solely on pasture should from the fescue pasture or hay before the last 3 months of gestation. not eat them unless restricted from have access to a trace mineral salt block quality sources of hay or pasture. to allow for adequate intake of minerals and salt.

3 Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability, or national origin. Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, C. Oran Little, Director of Cooperative Extension Service, University of Kentucky College of Agriculture, Lexington,4 and Kentucky State University, Frankfort. Issued 5-89, 10000 copies