University of Minnesota Extension
Menu Menu

Extension > Horse Extension - Ask an Expert > March 2015

Monday, March 30, 2015

Grazing Alfalfa

Question: I just bought a farm and the pasture has had grass and alfalfa in it for the past 10 years. Should I be concerned about grazing the alfalfa? I’ve heard horses should not graze alfalfa. 

Response: Horses can graze alfalfa. However, the major issue with pasturing horses in a mixed alfalfa grass pasture is the possibility of excessive weight gain. Even an all grass pasture can have excessive energy for adult horses at maintenance and light work, adding in alfalfa provides even more energy. 

As with any pasture, introduce horses slowly and delay grazing until forages reach 6 to 8” in height to optimize both the health of the horses and pasture. When pastures reach 6 to 8”, begin grazing for 15 minutes, increasing the grazing time each day by 15 minutes until 4 to 5 hours of consecutive grazing is reached. After that, unrestricted or continuous grazing can resume.
Alfalfa is not as tolerant to frequent grazing and mowing compared to cool-season grasses (i..e orchardgrass, bromegrass, bluegrass). It is likely that over time and with good pasture management, the alfalfa will continue to thin and the grasses will continue to thicken.
There are a few things you can do to if your horse(s) start gaining weight. Keep an eye on body condition score. Adult horse body condition score should not exceed 6 (out of the 9 point Henneke scale). If horses start putting on excessive body weight, use a grazing muzzle or restrict grazing to 6 to 8 hours a day (without feeding additional hay).

Finally, if any of your horses are hard keepers or have elevated nutritional needs, the mixed grass-alfalfa pasture will be ideal.

By:  Krishona Martinson, PhD, University of Minnesota 


Certified hay

Question: What is certified hay and how do you raise it?

Response: The invasion of noxious weeds causes substantial economic loss and ecological damage. Common sources for the introduction and spread of weed seed include the transportation and utilization of contaminated forages.

In Minnesota, the state agency in charge of certified hay is the MN Crop Improvement Association (MCIA). The Noxious Weed Seed Free Forage certification program is designed to assure that forage (hay, cubes and pellets) meets minimum standards designed to limit the spread of noxious weeds. Most public lands in the western U.S. require that hay transported into these areas be certified noxious weed free.

To grow Noxious Weed Seed Free Forage, famers must first submit an application for membership to MCIA and apply for field inspection stating the location of the field and expected harvest date. MCIA then inspects the field and intended storage site to determine conformance to standards for freedom from noxious and undesirable weeds. The farmer then harvests the eligible crop and submits a tag request for the bales harvested. Certification labels are then issued by MCIA for eligible bales. The labels must be attached to each bale prior to delivery.

 The MCIA website has additional information at, or they can be contacted by phone at 1-800-510-MCIA.

By:  Krishona Martinson, PhD, University of Minnesota



Fodder for Horses

Question: This year, hay has been difficult to find and is more expense than in past years. We are considering putting in a fodder system to feed our 30 draft horses. We were wondering if you had any information on this system. 

 Response: Hydroponically grown forage (or fodder) has become a new hot topic among livestock producers. There are several companies that are aggressively marketing these systems. With hydroponics, plants can be grown in a small amount of water on a mat with added nutrients, but without soil.

With hydroponics, forage is grown in a greenhouse and growth is usually fast. Harvesting can occur in as little as 7 to 10 days. Hydroponic growing systems have been specifically developed to sprout small grains and legumes, with most systems using barley. When the forage is grown, producers simply roll it up like a roll of sod (sprouted grass and roots) and feed it to livestock.

Many experts do not believe that hydroponically grown fodder is economical, especially if labor is figured into the total cost. Livestock owners should consider the following, the cost of the system to grow about 1,000 pounds of feed per day is over $45,000. This amount is what is needed to supply 36 pounds of dry matter to a herd of about 30 draft horses (assuming an 1,800 pound draft horse fed 2% of their bodyweight). The system is also labor and time intensive. Producers must consider the seed, disposable equipment, facility, fertilizer, heat, light, depreciation, and labor cost when decided whether to grow fodder.    

From the composition of the end product, it appears that little additional tonnage is added from growth of the small grain. The final dry weight is about the same as the grain seed weight. In some cases, dry matter is actually lost due to the respiration occurring during the early germination process. Many experts are concerned that the production of fodder adds nothing more than water, and that the nutrient and mineral content of the fodder (on a dry matter basis) is about the same as the barley seed used. The final fodder product is essentially a concentrate, not a forage due to the low amount of fiber. Therefore, additional forage would have to be fed to meet the fiber needs of horses and other livestock. Finally, fodder is about 90% water, so a significant amount will need to be fed to meet the horses dry matter requirement. 

Since a greenhouse, or similar structure, will be needed to produce fodder, there will likely be a learning curve in producing it. Producers are not likely to start with optimal production yields which can top 1,000 pound daily. Several conditions including outside air temperature (i.e. too hot or too cold) may reduce inside growth. When calculating the potential productivity of a fodder system, the local weather conditions must be taken into consideration. 

Even with high current hay prices, the most economical forage for livestock owners in the Midwest is legume and grass pasture and hay. This is true even in a drought year, and certainly in years when hay prices are more moderate. To help ride out high hay prices, have a good working relationship with a hay supplier to ensure a consistent and reliable source of hay; consider adding hay storage to reduce the effects of price and seasonal fluctuations; buy hay early, do not wait until later summer or fall; and finally, try and budget for the price increase. 

 By: Dan Undersander, PhD, University of Wisconsin and Krishona Martinson, PhD, University of Minnesota



PSSM and Moldy Hay

Question: I board my 4 year old quarter horse who has polysaccharide storage myopathy (PSSM). He is on pasture board with one other horse and they have access to a round bale. Last week the bale was new; this week it is the same bale and has been snowed and rained on and is now full of dust and mold. I know mold is bad, but is it worse for my horse since he also has PSSM? In 2013, he had four major PSSM episodes. 

 Response: Moldy hay is bad (and possibly deadly) for any horse and should not be fed. Horses ingesting moldy hay are at higher risk of respiratory disease and colic. If only 2 horses are eating off the round-bale, it would be best if it was covered by a feeder or placed inside a shed or lean-to to help reduce the negative effects of weather. Ideally, the round-bale would be consumed quickly enough so it would not mold during adverse weather. 

 Encourage the barn manager or owner to remove the moldy hay and take steps to avoid mold formation in the future.  Because the horse has PSSM, work with a nutritionist to ensure his diet (hay, grain, and treats) is at or less than 10% non-structural carbohydrates (NSC). Research from the University of Minnesota has shown that horses with PSSM respond better to diets lower in NSC. This, along with regular exercise (as long as its approved by your veterinarian), should help reduce the number and severity of his PSSM attacks.

By:  Krishona Martinson, PhD, University of Minnesota


City Water for Horses

Question: Is it okay for horses to drink city water that has had fluorides added to it? We’ll be attending a show soon and the show grounds are supplied by a city water source. Someone told us that city water could kill or poison our horses and we want to make sure it is okay, even for a short period of time.

 Response: It is common for horses to be exposed to city water while at suburban show and event venues. We know that horses are less susceptible to fluoride toxicity than cattle or sheep. Maximum dietary allowance of fluoride for horses is believed to be 40 ppm (mg/kg) in dry matter intake and 4 to 8 mg/liter in drinking water. The suggested maximum dietary allowance is substantially higher than normal fluoridation levels for municipal water supplies, which is 0.5 to 1.0 mg/liter of water. Cities monitor fluoride levels very closely in municipal water supplies. Most horses will drink approximately 40 liters of water (10 gallons) daily, or about 20 to 40 mg of fluoride. Keep in mind, horses can have up to 40 mg/kg of fluoride which translates into 18,000 mg of fluoride daily for a 450 kg (1,000 pound) horse. 

There have been reported cases of fluoride toxicity; however, these cases have been from industrial pollution/contamination or from the use of rock phosphate sources that have not been de-fluorinated.

 By: Roy Johnson, MS, Cargill Animal Nutrition



  • © Regents of the University of Minnesota. All rights reserved.
  • The University of Minnesota is an equal opportunity educator and employer. Privacy