Feeding For Breeding -

By Sarah Gee
©Voice, February 2006

The nutritional needs of both broodmares and stallions are unique. Each experience variances in their requirements throughout the year and each require feeding regimens that differ from idle and performance horses. Broodmares and stallions have specific jobs that they must accomplish and those jobs have specific requirements.

Broodmares
Body condition may be the single largest factor affecting the reproductive performance of mares. Mares kept in moderate to fleshy condition cycle earlier in the year, require fewer cycles per conception, have a higher pregnancy rate and are more likely to maintain pregnancies than are thin mares.

Throughout the year a broodmare goes through three different phases, each with a different nutritional demand. Those three phases are early to mid gestation, late gestation, and lactation. To keep a mare in this cycle, she must receive proper health care and nutrition. She must be maintained in optimum condition, which means that her feed ration must be adjusted for each phase.

Early to Mid Gestation
Non-lactating, pregnant mares in the first eight months of gestation have nutrient requirements very similar to those of any mature, idle horse. The developing foal gains only 0.2 pounds per day during this period and does not place a major nutritional demand on the mare.

During this time a mare’s nutritional needs may be met by free choice grazing of quality pasture along with supplemental minerals in the form of loose minerals or a mineral block plus loose salt or a salt block. A trace mineralized salt block will not provide sufficient minerals or salt to meet the mare’s requirements. Grazing mares will consume up to 3% of their body weight, which will meet their needs for protein and energy during this stage.

High quality hays can also be excellent for maintaining dry, pregnant mares in the early stages of pregnancy. As an average, mares will require approximately 2% of their body weight in high quality hay if no supplemental grain is provided. They will also need supplemental minerals and salt.

When pasture or hay quality declines, or is not available in adequate amounts, mares will need additional concentrate to maintain condition. A quality mix fed at .5% to .75% of body weight will help keep mares in good shape.

Late Gestation
During the last three to four months of pregnancy, a mare’s nutrient requirements increase because the unborn foal is growing more rapidly, averaging 1 pound per day. During this time the mare will need more protein, energy, vitamins, and minerals. Even if the mare is on quality pasture and appears to be in good condition, she’ll need quality concentrate supplementation. While forage may be able to provide sufficient calories to maintain the body condition of the mare, other nutrients, particularly protein and minerals, will be insufficient. Research has shown that the weight of the foal at birth can be adversely affected when mares do not receive enough protein during late gestation.

The unborn foal will retain the most minerals during the tenth month of pregnancy. Additionally, mares’ milk is practically devoid of trace minerals that are essential for proper bone development. Therefore, providing the mare with adequate minerals is vital to fetal development and is necessary to provide sufficient mineral stores for the foal to draw upon after birth. A supplemental feeding program that provides a good protein, vitamin, and mineral balance is necessary to properly support the growth and development of the foal.

Lactation
Nutrient requirements increase significantly following foaling. Protein and energy requirements as well as requirements for calcium, phosphorus, and Vitamin A almost double from early gestation to lactation. These needs must be met in order for the mare to recover from foaling stress, produce milk, and to rebreed, all without losing body condition.

Mares produce an average of 24 pounds or three gallons of milk daily during a five-month lactation. This represents 450 gallons or 1.75 tons of milk over 150 days. Milk production appears to peak at 30 days and slowly decline from there. The milk’s nutrient content follows a more drastic downward curve. By the fourth month of lactation, a mare’s milk provides less than 30% of the total energy needed by her foal. Giving mares a concentrate that includes added fats or oils and high quality protein can help slow the downward curve of production and improve her milk’s nutrient content.

During lactation, a mare will usually consume between 2% and 3% of her body weight in total feed daily. Because of the significant difference in nutrient requirements from gestation to lactation, it is recommended that a gradual increase in feed intake begin prior to foaling. Also, providing the total daily ration in two equal feedings allows mares to more safely consume the amounts needed during lactation.

Stallions
While limited research has been conducted on nutrition of breeding stallions, it is somewhat obvious that a stallion’s book, age, behavior, body condition, general health picture, routine handling, and level of free or forced exercise all impact how a sire should be fed. That said, during breeding season breeding stallions, on average, have daily nutrient requirements that are 25% above a mature idle horse.

Breeding stallions must be presentable to the public and should be able to complete the breeding season without appreciable weight loss. They should be maintained in a moderate to fleshy condition. The goal is to have a stallion in this condition as the season starts and then be able to meet his daily nutrient requirements with a reasonable amount of daily feed.

During the off-season, good quality hay or pasture is sufficient to maintain many non-working stallions. Stallions not being kept in show shape will usually do fine on all roughage diets, provided they are already in an acceptable body condition. Decent grass hay provided at 1.75%-2.0% of bodyweight or free choice grazing can be used. If fed high quality alfalfa, intake should be reduced to approximately 1.5%-1.75% of bodyweight per day. As with all horses, it is important to provide stallions with salt and other minerals.

Stallions that need to be kept in better shape during the off season, say for competition, and those that need to improve their body condition will need some concentrate feed. Stallions being ridden and trained and those requiring an improved body condition will often need a daily feed amount very similar to a breeding stallion.

To meet the increased nutrient requirements associated with breeding season, stallions should be provided a properly balanced concentrate. On average, stallions will require a total daily ration (concentrate + roughage) ranging from 1.5%-2.5% of bodyweight. It is important to select a concentrate that will also meet protein, mineral, and vitamin requirements. This will eliminate the need to provide extra supplements.

The average breeding stallion needs 40 grams of crude protein per megacalorie of digestible energy. Where horses receive roughage that contains 10% or more crude protein, a 10% crude protein concentrate will usually be sufficient. If the roughage contains less crude protein, the concentrate should contain more.

A stallion’s total diet should provide at least as much calcium as phosphorus. Stallions require 1.2 grams of calcium and .87 grams of phosphorus per megacalorie of digestible energy. To be sufficient, concentrates should contain at least .45% calcium and .35% phosphorus. Deficiencies in these two minerals can compromise the skeletal integrity of stallions at any age.

Contrary to popular opinion, breeding horses do not require supplemental Vitamin A or Vitamin E. Properly formulated feeds from reputable companies are convenient to use and contain required levels of these vitamins. Additionally, most have been fortified with trace-mineralized salt at levels to meet the requirements of the average stallion.

During breeding season, most stallions thrive on a daily ration that has a 50:50 up to a 70:30 ration of roughage to concentrate. This will be influenced by individual stallion differences, hay quality, and the energy density of the concentrate being fed. Almost any concentrate feed will satisfy a stallion’s energy needs, but some would have to be fed in such large amounts that digestive tract well being and health could be compromised. On the other hand, some concentrates are so energy dense that very small amounts of feed will meet energy needs not provided by the hay or pasture. Expected energy density of most formulated feeds can be estimated by looking at the crude fiber and fat percentages on the feed tag.

If careful feeding management is practiced routinely, stallions with no special digestive problems will often be best served by a concentrate containing 8% or less crude fiber. Such feeds are more energy-rich than higher fiber feeds and will typically help maintain acceptable body condition with a smaller amount of total daily feed.

Fat-supplemented concentrates can be very practical and beneficial for old stallions that may tend to be thin and for horses that are extremely active. The fat-supplemented feeds provide more energy than a traditional concentrate of similar crude fiber level in the same amount of total feed.

References:

Davison, Dr. Karen E., Nutritional Management
of Pregnant and Lactating Mares,
Purina Mills, LLC.

Gibbs, Dr. Pete G., Stallion Nutrition, Animal
Science Department, Texas A&M University.

Warren, Dr. Lori K., Feeding the Broodmare, a
publication of the Department of Agriculture,
Food and Rural Development, Alberta, Canada.

Warren, Dr. Lori K., Feeding the Stallion, a
publication of the Department of Agriculture,
Food and Rural Development, Alberta, Canada.