The broodmare has substantial increases in requirements for digestible energy, protein, lysine and minerals as she goes from the last month of gestation to the first month of lactation. For an 1100 lb mare, the following changes occur:

• Her DE requirement goes from 21.4 Mcal per day to 31.7 Mcal per day
• Her protein requirement goes from 630 grams to 1535 grams per day
• Her lysine requirement goes from 27.1 grams to 84.8 grams per day
• Her calcium requirement goes from 20 grams per day to 59.1 grams per day
• Similar increases occur in other amino acids and minerals, as well. They are documented in the Nutrient Requirements of Horses, Sixth Edition, pages 298-299.

If her feed intake is not increased to provide these nutrients, she will maintain milk product by using her body stores for energy, amino acids and minerals, causing loss of weight and loss of body condition as well as mineral losses.

Ferris with mom Rosie - foals exhibit the most entertaining behaviors....

To meet her increased DE requirement, an additional 7.5 pounds of grain containing 1364 Calories/lb will need to be added to her diet gradually post foaling. Fortunately, she also can consume more dry matter during lactation, so she is actually able to eat more forage and more feed. If she is fed a product suitable for lactating mares, the additional feed will provide the additional energy as well as the other important nutrients. She will also require unlimited access to water and salt free choice along with good quality forage.

If she continues to lose weight, she is much less likely to cycle normally during lactation and less likely to become pregnant and carry the next foal. This may be why some mares are “every other year” mares in producing foals. They are frequently mares that produce large foals and milk very heavy during lactation. As a result, they do not maintain body condition and do not re-breed and carry a foal the next year. When they are not in foal and not lactating, they gain weight and come back into the next breeding season in good flesh and breed successfully. This is even more likely if they are not in a suitable body condition (BCS 6+) prior to foaling.

The nutrient requirements of the mare will start to decrease at the 3rd month of lactation and will gradually decrease until the foal is weaned. Monitoring body condition of the mare and the foal is one of the best ways to determine if the feeding program for both is producing the desired results!

Since we cannot increase the feed intake drastically when the mare foals, she needs to be carrying some extra fat stores so she does not drop body condition drastically before we can bring her up to intake levels that fill lactation energy requirements.  Mares should be at about a body condition score 6 when they foal so that they have sufficient energy reserves for early lactation as well as to maintain condition for re-breeding. If she is in a significant negative energy balance (losing body condition) she is much less likely to rebreed easily and carry the next pregnancy.

To bring a mare along properly in her nutritional journey, here are some general guidelines to keep in mind:

• Good quality pasture or forage may provide sufficient energy thru late gestation, but may not provide adequate amino acids and minerals. 
• A ration balancer product or a feed designed for pregnant mares may be used from month 5 to about month 10 or 11 of gestation to provide the missing nutrients. 
• A feed designed for broodmares and foals should be introduced prior to foaling, so that the mare is properly adjusted to the feed well before she foals.  She is under quite a bit of stress immediately before foaling, so this is not the time to be introducing a new feed. This feed can then be increased after foaling to provide both the increased energy and the increased nutrients that are required for lactation, as well as providing nutrition for the foal when it starts to nibble on feed. 
• Fresh clean water and free choice salt should also be available at all times.
• The mare should also be vaccinated properly before foaling so that her colostrum, the rich first milk, contains antibodies to protect the foal.  Proper nutrition will also help immune response to vaccinations.

During lactation, a mare’s energy needs are easily doubled over her maintenance needs, and while a mare is producing milk for her offspring, her water consumption can exceed 50-100% that of a maintenance horse. Around 13-24 weeks after the mare has given birth, her milk production will begins to decrease, and the diet can start to be cut back slightly as nutritional needs are getting back to those of a normal maintenance horse.

Feeding the broodmare properly can help reduce the risk of developmental problems for the foal and help insure that the mare can be rebred in a timely manner to produce another foal the following year.

Lactation demands a lot from a broodmare!

Are you anxiously awaiting that first foal of the spring? Do you have the foaling stall ready, the vet on speed dial, and the video camera on the battery charger? While you’ve been busy prepping, here are some of the amazing changes that have taken place (or are about to take place) in your mare:

• 6 Month Mark: During 2^nd half of pregnancy, 60 – 65% of fetal growth occurs!
• Energy requirements of the mare go up almost 30% over a normal maintenance horse – from 16.7 Mcal DE per day to 21.4 Mcal DE per day.
• Her protein requirements will increase 32%, and vitamin and mineral requirements also increase significantly during this time.
• The mare needs to be receiving adequate calcium, phosphorus, magnesium, copper, zinc, manganese and selenium to provide minerals for the development of the foal and to build the foals own trace mineral reserves.  Trace minerals are also critical for immune support. 
• Adequate protein/amino acid intake is essential – lysine, methionine and threonine, the first 3 limiting essential amino acids, need to sufficient in the diet for placental and fetal development.
• Last Trimester: The average foal fetus will grow by 1 pound per day!
• Lactation: After the foal has been born the real work for the mare is just beginning.
• The normal mare will produce around 24 lbs (3 gallons) of milk per day. During an average 150 day lactation, this equals 450 gallons or 1.75 tons of milk!
• During lactation, a mare’s energy needs are easily doubled over her maintenance needs – from 16.7 Mcal DE per day to 31.7 Mcal DE per day!
• While a mare is producing milk for her offspring, her water consumption can exceed 50-100% that of a maintenance horse.
• Around 13-24 weeks after the mare has given birth, her milk production will decrease from 3% of her body weight to around 2%.

With all that effort going into producing a darling new foal for your farm, be sure to give your mare an extra pat on the neck, and of course, make sure you are feeding her properly!

If these minimum requirements are not met, the horse may experience deficiency symptoms.  The severity of the deficiency symptoms may depend on the degree of the deficiency and the time period over which the deficiency exists. 

• A sub-clinicaldeficiency may be the result of a small deficiency over a period of time. 
• Subclinical deficiencies may also result in decreased immune response, decreased reproductive efficiency and decreased performance.
• A clinical deficiency is present when there are readily observed or measured symptoms.

Perhaps the easiest example is a deficiency of energy (Calories) in the diet.  The more severe the deficiency, the faster the horse will lose weight.  If a horse is losing a quarter of a pound per day, the loss will take some time to be visible. Over the course of 6 months, the horse would lose 45 pounds or about a full body condition score.  Over the course of a year, the horse is almost 100 lbs underweight or goes from a body condition score 5 to a 3.

If the horse is getting sufficient Calories, but is deficient in protein or essential amino acids, the body condition might appear OK, but the hair coat might get dull, the hoof quality might deteriorate and the muscle tone might be lost.  This is common for horses that are on pasture that has adequate energy content, but is short on amino acids or other nutrients.  If the diet is deficient in key fat soluble vitamins such as A, D and E, it might take longer for the deficiency symptoms to show up as the animal will use up stored vitamins first.  If there are mineral deficiencies or imbalances the symptoms might show up in either bone problems or reproductive problems.

Mineral imbalances can create deficiency symptoms as well.  A diet that contains a large excess of zinc might produce symptoms consistent with copper deficiency.  An excess of phosphorus, creating an inverted calcium to phosphorus ratio (less than 1:1), can produce nutritional secondary hyperparathyroidism or “Big Head” disease as well as other bone issues.

The diet below illustrates a diet that might produce some sub-clinical issues over time.  This is a fairly typical grass hay and oat diet and uses basic NRC requirements for an 1100 lb horse at light work.

Percent of nutrient needs that are met with a traditional horse diet of oats and hay.

Offering salt free choice would take care of the sodium (Na) deficiency, but there would still be some trace mineral and vitamin shortages in the diet.  The extra magnesium in the diet would not be expected to be a problem.

Using a ration balancer horse feed product would be one solution. Using a properly fortified commercial feed that contains meets all of the requirements when fed as directed would also be a good way to prevent the development of clinical or subclinical deficiency symptoms.

A hanging scale, such as this (dirty) one is helpful to hang a bucket from and weigh feed. Note that the scale has been tared for a bucket.

Horse owners frequently compare feeds based primarily on the information on the feed tag or supporting data from web sites.  While this is a quick comparison to make, it may not always be the best comparison.  Why, you ask? Well, what is most important to the horse is the total amount they actually consume.  To get this number, the percentage in the feed must be multiplied by the amount fed, making sure to account for different unit of measurements, such as supplements that are fed in ounces instead of pounds.

One example where this is important is with the protein percentage.  As ration balancer horse feed products are becoming more and more popular, some folks see that they typically have 30% protein or more, and worry that the level is way too high for a horse.  But with a ration balancer, a 1000 lb horse only gets 1-2 pounds of the product a day, compared to 4-6 lbs of a more traditional 12% feed.  So, if we do the math, here’s what we see:

• 30% protein X 2 lbs of feed = 0.6 lbs of protein a day from a ration balancer
• 12% protein X 5 lbs of feed = 0.6 lbs of protein in a day from a traditional feed

Another example where this calculation is useful is in the variety of fat supplements available on the market today. 

• A powdered fat supplement has 99% fat, being fed at a rate of 2 oz a day, adds 0.124 lbs of fat to the daily diet.
• A stabilized rice bran supplement that has 22% fat, fed at a rate of 2 lbs per day, adds 0.44 lbs of fat to the daily diet.

And of course, on top of this, we must ALWAYS remember to factor in the hay – not just the grain.  A horse will consume much more hay per day than grain, so the difference in a few percentage points is magnified when looking at the hay portion of the diet.  It may take a little math, but looking beyond the percentage of a particular nutrient is something your horse would thank you for if he could speak!

Because fiber is such a huge part of your horse’s healthy diet (he should be eating no less than 1% of his bodyweight daily in hay or pasture) it is essential that it is present in nearly everything he consumes. With manufactured feed we are able to control the amount of fiber in the ration by using some specific ingredients.  Using alfalfa/legume products can  help to add protein, energy and calcium to the feed, while grass products can help add protein and fiber. Some of the most common sources of fiber in horse feeds are:

• Alfalfa Meal
• Dehydrated Alfalfa
• Suncured alfalfa
• Coastal Bermuda Grass
• Ground Grass
• Ground Soybean Hay

It is important to always remember to read your feeding recommendations – just because a feed utilizes one or more of these forage products and has a high fiber content that does not mean that it can be fed as a sole ration.

When grains are used in horse feeds they are most commonly processed to help enhance digestion. Processing methods can include cracking, screen cracking, flaking, kibble, toasting or heat processing . The grains that  can be fed to horses include triticale, wheat, rye, rice and grain sorghum although these are much less common than “The Big Three” grains that are most typically used in horse diets:

• Corn is added to feed as an energy source and provides a whopping 1.54 Mcal of digestible energy (DE) per pound. However, corn is also one of the grains that is highest in content of starch. Whole corn is not typically used in textured horse feeds unless it is processed (flaked , cracked, etc.), and fine ground corn should not be used in textured feed because it increases the risk of colic. While it has received a bit of a bad rap in recent years due to its higher starch content, it can be, and is, still a valuable piece of the formulation of a total feed, as long as the proper attention is given to the overall starch level of the finished feed.
• 

  Oats is one of the more common grains used under the heading of Grain Products

  Oats are probably the most traditional grain fed to horses. Oats provide a source of fiber but energy content is considered low for a cereal grain, and they have a moderate amount of starch when compared to other straight grain rations. Whole oats consist of clean, cultivated oat grains. Crimped oats have the hull of the oat broken while rolled oats have been steamed and rolled flat.

• Barley is also an energy source, and has a fiber and starch content somewhere in between oats and corn. Whole barley consists of whole kernels of barley with the outer covering intact. Barley has a tougher hull than oats, so it is most commonly processed (crimped, rolled or steam flaked) when put into horse feeds. Whole barley is used in some instances, but is not ideal.

• Beet Pulp: this is a by-product of the sugar beet industry. It is the dried residue that has been extracted in the process of manufacturing sugar from sugar beets. Beet pulp has long been fed as a way to put weight on horses.
• It is high in digestible fiber and digestible energy and is low in starch, which makes it fairly safe to feed.
• Beet pulp pellets are usually soaked when fed; this can also help increase water intake.
• However, beet pulp by itself is not a balanced product. It can fit very well into a feeding program, either as a supplement or as an ingredient in a commercial feed, but if fed by itself the horse will be missing essential minerals, amino acids and protein.
• Soy Hulls: these are the outer covering of the soybean. These hulls are removed before soybeans are crushed for oil, and are an excellent ingredient that is mainly used in pelleted feeds.
• They provide a good source of energy and are an easily digested fiber source.
• Oat Hulls: these are the outer covering of the oat kernel.
• They are high in fiber, low in energy, and low in protein.
• Because of their high fiber content they make a good source of roughage.

These are a few of the most common sources of roughage. Depending on where you live, there may be other more prevelant sources of roughage available. No matter what the specific ingredient is, the main function of roughage in the diet is to provide bulky fiber that helps pull the contents of the digestive tract along and assist in keeping the gut functioning.

Wheat Midds are obtained from the milling of wheat, wheat bran, wheat shorts, wheat germ, wheat flour, etc.  Midds are a good source of energy, protein and fiber for horses. Additionally, wheat midds help create a nice pellet that holds together well; midds can enhance the pellet quality and make a clean pellet with minimal dust and fines.  

Rice bran is a by-product of the rice milling process. Rice bran is found between the outer hull and inner grain of rice and is used as a plant-based fat source (typical rice bran products contain 20% fat or more). Rice bran can be fed in a powder form, extruded into a nugget, or added to commercial rations and pelleted to increase overall fat content of the feed. Rice bran works well as an ingredient but must be balanced to make up for a high phosphorous and low calcium content. It also must be stabilized or it will turn rancid very quickly due to the high oil content.

Wheat Bran is a by-product of the flour industry. It is rich in dietary fiber and essential fatty acids; bran mash has been historically fed to horses both as a treat and for a laxative effect that was thought to prevent colic.  We now know that too much wheat bran can cause problems such as enteroliths, and that laxative effect is actually a result of too much wheat bran irritating the gut lining of the horse. Similar to rice bran, wheat bran intakes must be managed to account for a very high phosphorous content.

These are just a few examples of some common grain by-products that are used in horse feed and can help create a healthy and nutritious diet. While not a “grain” by-product, even the ever-popular beet pulp is a by-product – it’s what’s left after sugar beets are processed! Before you dismiss a feed because it lists by-product as an ingredient, remember that these items, when balanced properly as a part of the overall formulation of the diet, can be an excellent source of many different nutrients.

Soybean Meal – This is the most common form of plant protein. Soybeans are readily available throughout the country and have the highest concentration of protein of any of our plant sources, with a typical level of 44-48%. Additionally, soybean meal contains a close match nutritionally to what horses require for amino acids. Especially important in this profile is the amino acid lysine, which is essential in young growing horses.

Canola Meal – Canola meal is the closest to meeting the nutritional profile of soybean meal and has a protein content of 35-44%. Canola meal is a by-product of oil removal from

canola and has slightly less lysine content than soybean meal, but still enough to meet the requirements of horses.

Linseed Meal – this is also a by-product and is derived from the processing of flaxseed. Linseed used to be commonly fed to show horses to add shine and bloom but its popularity has waned as ingredients like rice bran and vegetable oil have taken its place. Linseed meal has a typical protein level of 33 – 35% but it has significantly less lysine than either soybean or canola meal.

As you can see, we have several options to help us meet the requirements that our horses have for protein. By adding one or more of those options to our formulas we are able to provide a diet that is balanced, healthy, and nutritious!