Feeding Stallions

Reprinted courtesy of:
The University of Tennessee Agricultural Extension Service,

April, May, June 2004

Dr. Frederick Harper, Extension Horse Specialist
Department of Animal Science

The stallion is the most valuable animal in a breeding program. He sires several foals annually compared to one per broodmare. The stallion(s) may be the major income
source in some horse operations. Even with his importance, there is less research and
educational emphasis on feeding and management of stallions than on mares. Most stallion research is in the area of reproduction.

The breeding stallion's year can be divided into four feeding and management periods: post-breeding, nonbreeding, pre-breeding and breeding season (Table I). It will be helpful to begin this discussion with the postbreeding period.

Post-Breeding
The breeding season ends about July 1 for most breeders. Some fall breeding occurs in Tennessee Walking Horses as fall foals are registered as foals of the following year.
The stallion manager must make changes at the end of the breeding season to transition the stallion's attitude from a breeding to a non-breeding status and adjust his feeding program. Horses become conditioned to routine so the stallion's schedule must be changed.

Each stallion should have two halters and lead shanks. Use one pair for
breeding only and the other for all non-breeding activities and during the non-breeding periods. The stallion should get more exercise now and be outside in pasture paddocks,
allowing him to graze more. Daily procedures, such as grooming, should be changed to recondition the stallion to a non-breeding attitude. The stallion should become more
relaxed in a few weeks. If a breeding attitude continues, place the stallion on a forced exercise program. Forced exercise resulted in decreased sperm, testicle size and lowering of some hormones in one study.

Evaluate the body condition score (BCS) at the end of the breeding season. Stallions will have 1) a lower BCS, 2) a higher BCS or 3) show little change in BCS from the start of the breeding season. Some stallions are so active and fretful in the breeding season they become thin with BCS of 5 (moderate) or lower. A stallion in a 3 BCS range is not an emergency, unless he is sick. A stallion losing 200 pounds in the breeding season needs to gain 1 pound per day until the next breeding season starts.

You have several months (Table I) to adjust the thin stallion's BCS before the next breeding season. Teeth, deworming and sickness must be considered in all thin horses. Stallions, especially older ones, may have developed teeth problems from eating hay. A veterinarian can rasp off these sharp points. Stallions should be on a routine deworming program from September 1 to March 1. There is no value in deworming stallions, or any mature horse, in the summer. If no teeth, eworming or health issue exists, your focus will be on properly feeding the thin stallion to gain weight and body condition. Mares lose BCS, thus body fat, while lactating but restore it after foals are weaned. A similar process likely occurs in some stallions; though, breeding is not as nutritionally demanding as lactation. Stallions should be on pasture as much as possible.

Cool-season forages in the Southeast are not as productive in July and August. If pasture is limited or not available, feed stallions a good-quality grass hay. There is no need to feed alfalfa at this time. Do not feed a large amount of grain. The amount fed depends on 1) the stallion's BCS, 2) the quality of the pasture and/or hay, and 3) how rapidly you want the stallion to gain body condition. Normally, the stallion probably needs less than 0.5 pounds of grain per 100 pounds of body weight – 6 pounds of grain or less for a 1,200-pound stallion. If feeding 6 or more pounds per day, feed the horse twice daily. Feed the least amount of grain needed to balance the forage (pasture and/or hay). Thin stallions need a high-energy feed with corn (maximum of 23%) and added fat (6-10%). Corn and fat are good energy sources and cooler feeds than oats in the summer. A 10% protein grain mix is adequate. Provide clean, fresh water and a source of trace mineralized salt. Added supplements are not normally needed if stallions have good-quality pasture or hay and a balanced grain mix. Most commercial grain mixes have added minerals and vitamins.

A target for thin stallions would be a BCS of 5-5.5 by September. Horses can put on one BCS in 30-60 days. Stallions in a desired BCS at the end of the breeding season should be kept near that level until the pre-breeding period, which may not be easy. Continually monitor BCS status in the post- and non-breeding periods. Feed less grain than in the breeding period. If BCS increases, reduce or eliminate grain in the post- and non-breeding periods. Good-quality pasture and/or hay alone may be adequate
to maintain BCS in these stallions. If a stallion's BCS declines from 6.5 to 6 in July or August on lower-quality pasture, do not worry. You have several months to get him
to a BCS of 6.5 by mid-February. It is better to begin the pre-breeding period 0.5 BCS under the desired BCS level. Stallions that exit the breeding season too fat need
to lose body fat. Over-fat stallions have increased risk of colic, laminitis and other health issues. Obese stallions (BCS 8 or 9) may have lower libido. The desired BCS for stallions ranges from 5.5-7.5. Most stallions do well with a BCS of 6-7. Older stallions with arthritis may be healthier and function better at a BCS of 5.5, making it easier for them to mount a mare or dummy.

It is not advisable for horses to be above a BCS of 7.5. Stallions are likely to be overweight as some owners think that “fat” stallions attract more mares. Stallions with a
BCS of 7.5 or above at the end of the breeding season need to be on a diet in the post-breeding period. They can be on pasture without grain. If pasture is limited, feed an average quality grass hay at a level of about 1.00-1.75 percent of normal body weight, not their current overweight. If grain must be fed, feed a small amount of oats.

Non-Breeding Period
In the post-breeding period, the stallion's routine and feeding program were adjusted to change his attitude and BCS after the breeding season. The non-breeding period extends from the end of the post-breeding period until 45-60 days before the breeding
season (Table I). Nutrition in the non-breeding period is at a maintenance level with the stallion fed as a mature, nonperforming horse (Table II). Maintenance is the lowest nutritional demand for mature horses (Table II). Cool-season fall pasture may properly maintain the stallion. If adequate pasture is not available, feed a good-quality grass hay at 1- 2 percent of body weight. Grain is not needed if a stallion has adequate BCS. If you must feed grain, feed only 1-2 pounds of oats. Older stallions may be fed a "senior” feed. Fresh, clean water and trace mineralized salt are always necessary. Older and nervous stallions may require more grain to maintain BCS. Feeding 0.25 - 0.33 pounds of grain per 100-pounds of body weight (3-4 pounds) should be adequate. Stallions should be exercised daily. Deworming should begin September 1 and continue until March.

Pre-Breeding Period
The key of the pre-breeding period is to get the stallion physically fit and nutritionally ready with a suitable BCS for the breeding season. Mares gaining weight come in estrus a month earlier than those losing weight. Improving body condition should be positive for stallions also. Pre-breeding may be the most important period for the stallion. He should begin the pre-breeding period about a 0.5 BCS below what you want at the start of the breeding season. Most breeding seasons start about mid-February,
so you have time to increase BCS.

1Post-Breeding and Non-Breeding Periods
2Pre-Breeding and Breeding Periods
3National Research Council, 1989.
4Kentucky Equine Research, 1997.

The stallion is fed like a light performance horse with 25 percent more energy (Table II). The stallion is being prepared for 4-4.5 months of breeding. This is no time to
ignore management. Pasture is not normally available, so feed a very good-quality grass hay, alfalfa or mixed hay. Grass hay is usually fed at 2 percent of body weight and legume hay at 1.75 percent. Never feed the stallion less than one percent of hay. Feed the same grain mix used during the breeding season – a high-energy feed with added
fat and 12-14 percent protein. Feeding more protein is not beneficial and results in strong ammonia odor in the stallion barn. If the grass hay is of lower quality, use a 14 percent protein grain mix. Commercial grain mixes usually have added minerals and vitamins. Feeding a mineral and vitamin supplement in a balanced feeding program has not proven beneficial to broodmares.

In mid to late December place the stallion in a new exercise regime to prepare him for the strenuous and long breeding season. Exercise is critical to get the stallion physically fit for this level of activity. It normally takes six to eight weeks to get a horse fit for light performance such as pleasure riding or rail classes. The stallion's cardio-vascular system must be fit. Older stallions that died at their first or second breeding of the season had a ruptured aorta. Having them physically fit before the breeding season is absolutely necessary. Exercise is a critical management component of the pre-breeding and the breeding season. Stallions that lost BCS in the previous breeding season can be pre-conditioned to a higher BCS (7.5) by the start of the next breeding season.

Breeding Season
The stallion's success in settling mares the previous year, age and value will determine the number of mares booked to him. Do not over book older or younger stallions. There are no magic nutritional bullets to improve a poor breeding stallion's fertility. Supplementing vitamin E to a stallion fed a balanced grain-hay ration had no effect on mean reaction time or number of mounts per ejaculate. Motility, pH, concentration and total sperm per ejaculate were unaffected. Mature stallions supplemented with vitamin A did not have improved seminal characteristics nor scrotal width when also fed a grass hay containing four times the recommended levels of beta-carotene (vitamin A precursor) These data show that vitamin E or A supplementation of stallions is not needed when feeding a balanced
ration.

The nutritional demands of breeding equal light performance, a 25 percent increase in energy above maintenance. It is better to feed an energy dense ration than to feed more grain. Such a feed reduces the risk of colic and founder, meets the stallion's nutritional needs, and keeps him fit in the breeding season. A 25 percent increase in energy may not be adequate for some stallions. Feeding hay free-choice in the breeding season is a
common practice. This is important when pasture is not available or limited. Hay has a satisfying effect and may keep stallions more tranquil in the breeding season. Feeding
alfalfa hay free-choice may not be advisable for older stallions or those that get too fat. Kidney problems have been reported in older horses fed alfalfa hay. Feed breeding stallions about 0.5 pounds of grain (12-14% protein) per 100-pounds of body weight. The ratio
of forage to grain is 70:30. Some stallions may need more energy, so feed grain at 0.75 percent of body weight. Grass hay is usually fed at 2 percent of body weight while legume hay is fed at 1.75 percent. A 1,000-pound stallion would be fed 5 pounds of grain and a 1,200-pound one 6 pounds of grain. Anytime 6 or more pounds of grain are fed, feed twice daily.

During the breeding season, BCS each stallions every two weeks and make needed adjustments in the feeding program. Stallions with BCS above 7.5 should have their grain level reduced. Stallions that lose BCS early in the breeding season need a more energy-dense grain mix, which is preferred over more grain. Fat-added grain mixes would help stallions that do not eat well or lose BCS in the breeding season. “Senior feeds” may aid some older stallions.

Stallions in the breeding season are exercised in turn out paddocks three or more times weekly or some are also ridden. Forced exercise programs get stallions fit but result
in a decrease in normal sperm. For this reason, it may not be a good idea to show stallions in the breeding season. Routine turn-out in paddocks or riding 3-4 days per week is not forced exercise. The breeding stallion's BCS, health and attitude must be closely monitored. Stallions should not experience major changes in BCS in the breeding season. Start feeding a high-quality, energy-dense grain mix in the pre-breeding period and continue feeding it in the breeding season. Adjust the amount up or down as stallions lose or gain in BCS but do not change feeds during the breeding season. Twice monthly BCSs with appropriate adjustments in grain intake should have stallions ending the breeding season at a desired BCS. This results in fewer management adjustments in the post-breeding period.

References
Gibbs, P. G. Stallion Nutrition. ASWeb-015. Texas A&M University. College Station, Texas.
MicroSteed. 1997. Kentucky Equine Research, Inc. Versailles, Ky.
National Research Council. 1989. Nutrient Requirement of the Horse. Washington, D. C.
Ralston, S. L., S. A. Jackson, V. A. Rich and E. D. Squires. 1985.
Effect of Vitamin A Supplementation on the Seminal Characteristics and Sexual Behavior of Stallions. Proc. 9th Equine Nutrition and Physiology Society. East Lansing, Mich.
Rich, G. A., D. E. McGlothlin, L. D. Lewis, E. L. Squires and B.
W. Pickett. 1983. Effect of Vitamin E Supplementation on Stallion Seminal Characteristics and Sexual Behavior. Proc. 8th
Equine Nutrition and Physiology Society. Lexington, Ky.
Taylor, M. J., J. W. Evans, D. D. Householder, G. D. Potter and D.
D. Varner. 1997. Reproductive Parameters of Breeding Stallions in Response to a moderate Physical Conditioning Program. Proc.
15th Equine Nutrition and Physiology Society. Fort Worth, Texas.

Tennessee Horse Express
From:
Leader/Agent
Associate Professor, Extension Animal Science
The Agricultural Extension Service offers its programs to all eligible persons regardless of race, color, national origin, sex, age, disability, religion or veteran status and is an Equal Opportunity Employer.

COOPERATIVE EXTENSION WORK IN AGRICULTURE AND HOME ECONOMICS
The University of Tennessee Institute of Agriculture, U.S. Department of Agriculture,
and county governments cooperating in furtherance of Acts of May 8 and June 30, 1914.
Agricultural Extension Service
Charles L. Norman, Dean
04-0321 E12-4415-00-004-04