Ask the Expert: Maple Leaf Toxicity

Question: Our horse pasture has several maples trees. I was told they are toxic to horses, but our horses seem fine. Are they toxic? If they are, do we have to remove them from our pasture?   

Answer: Wilted (not fresh) maple leaves are toxic to horses. However, horses must eat 1.5 to 3 pounds of wilted maple leaves per 1,000 pounds of bodyweight to become sick.  Wilted maple leaves can remain toxic for four weeks, but they aren’t generally believed to retain toxicity the following spring. Thus, illness normally occurs in the fall when normal leaf fall occurs. 

Illness from maple leaves has only been reported in horses. Common signs after the first day of eating leaves include depressed behavior, tiredness, not eating, and dark red/brown urine. Signs may progress to going down with labored breathing and increased heart rate before death. Don’t cut down maple trees in horse pastures. Instead, keep branches out of reach of horses (for example, trimmed above their reach) and fence horses out of areas with a lot of wilted maple leaves. However, horses will rarely choose to ingest wilted maple leave unless very hungry. For more information on wilted maple leave toxicity, click here

Written by Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Frost Concerns for Grazing Horses

Photo Credit: Krishona Martinson, PhD, University of Minnesota

Fall can be a beautiful time of year for horseback riding. However, frost can negatively impact horse health during fall grazing. 

There are no reports of toxicity of horses grazing frost damaged pastures (includes grass and legume species). However, frost damaged pastures can have higher concentrations of nonstructural carbohydrates, leading to an increase in potential for founder and colic, especially in horses diagnosed with or prone to obesity, laminitis and Equine Metabolic Syndrome. To help prevent these health issues, wait up to a week before turning horses back onto a pasture after a killing frost. Subsequent frosts are not a concern as the pasture plants were killed during the first frost.

Why do nonstructural carbohydrates increase during the fall? During the day, plants carry out the process of photosynthesis. In this process, they make carbohydrates as an energy source for the plant. A second process, respiration, is carried out when the plants use up the carbohydrates they produce during the night for energy. Plant respiration slows down when temperatures are near freezing. As a result, the plants hold their carbohydrates overnight. Freezing can stop respiration and lock the carbohydrates in the plant for over a week. Thus, plants tend to contain more carbohydrates in colder temperatures or after a frost. Often, horses will prefer forages after a frost due to the higher carbohydrates levels.

For more information on fall health concerns for grazing horses, click here

Written by Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.
  

Ask the Expert: Feeding Preservative Treated Hay

Photo Credit: Krishona Martinson, PhD, University of Minnesota

Question: Our regular hay supplier applied a preservative (propionic acid) to the bales this year. What is that and is it safe for horses?   

Answer: Preservatives are commonly used during times of frequent rainfall or poor drying conditions (e.g. high humidity or heavy dew). Propionic and acetic acids are commonly used hay preservative that are applied to hay as it is baled to allow baling of wetter than normal hay without spoiling during storage. Moisture at the time of baling is directly related to mold formation. Hay baled at ≤15% moisture is unlike to mold; however this is impacted by bale-type and mass. For example, small square bales can be baled up to 18% moisture with limited risk of mold formation; however, large round bales must be baled at ≤15% moisture to reduce the risk of mold formation. Preservatives are most effective at inhibiting mold growth, and most economical, when the hay is baled between 18 to 25% moisture. 

Preservatives are safe for use in horse hay. Researchers found that when given a choice, horses preferred hay that was not treated with a preservative; however, horses readily consumed the treated hay when a choice was not given. Yearlings receiving hay treated with a preservative consumed and gained just as much as yearlings consuming untreated hay, and clinical measures of well-being were not affected by consumption of preservative-treated hay. Interestingly, a horse’s hindgut bacteria actually make propionic acid as a result of microbial fermentation.

Therefore, feeding horses hay treated with a preservative is a safe and common practice, especially in years when poor weather conditions exist for making hay, and helps to inhibit mold growth during storage.

Written by Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Ask the Expert: Grazing a Newly Seeded Pasture

Question: This spring, we planted 2.5 acres of pasture for our horses. The grasses are now 6 inches tall and the stand density appears good. Should we mow the pasture? If so, how often? When should we start grazing?  

Answer: You will want to mow the pasture 3 times before allowing the horses to graze. Since the grass is 6″ tall, mow it down to 3″ and allow it to re-grow to 6″, then mow again. Follow this cycle until you have mowed the pasture 3 times. This is critical since new grass seedlings need time to firmly root into the ground. Mowing helps to stimulate root growth and anchors the plant without the physical pressures of grazing. If the pasture is grazed too soon, horse can pull new grass seedlings out of the ground. Mowing will also help control some weeds that are common in new pasture seedings.

Once you have mowed 3 times and the grass has regrown to 6″, you can start grazing the horses. If the horses are acclimated to pasture, they can be allowed to graze until the pasture is, on average, grazed down to 3″. At this time, you would rotate the horses off the pasture, mow the pasture to 3″, allow the pasture to regrow to 6″, then graze again. You would keep repeating this process until the pasture stops regrowing in the fall; it is critical to allow the pasture to rest and regrow. Unfortunately, horses do not graze uniformly, so mowing is necessary to ensure the pasture regrows evenly, plus mowing will help control some weeds.

If your horses are not acclimated to pasture, then start grazing in 15 minutes increments, adding 15 minutes each day until you reach 5 hours of consecutive grazing. For example, 15 minutes on day 1, 30 minutes on day 2, 45 minutes on day 3, etc. This allows the horses to slowly acclimate to pasture and reduces the risk of laminitis and colic that is often seen with abrupt diet changes.

Along with mowing, make sure to drag manure piles 2 to 3 times a year during hot and dry times, fertilize as needed, and control weeds. For more information on pasture management, click here.  

Written by Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Initiating Spring Grazing

Spring has sprung, and that means that it’s time to prepare your horses and pasture for spring grazing. Here are some quick tips to keep in mind:

Is your pasture ready?

  • Check and repair all fencing and gates.
  • Check that water sources are clean and working.
  • Begin grazing when a majority of the pasture is 6 to 8” tall.

Are your horses ready?

  • Schedule annual dental care
  • Test manure to determine fecal egg count and deworm accordingly to reduce parasite load on the pasture.

Start grazing!

  • Start with 15 minutes per day.
  • Add 15 minutes each day until 5 hours of grazing is reached, then unrestricted grazing can begin.
  • Stop grazing when a majority of the pasture is grazed down to 3″ to 4” tall and rotate to a new pasture or dry lot.

Written by Aubrey Jaqueth, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Horse Drooling? Ask the Expert: Slobbers

Horse DroolingQuestion:  My horse is drooling excessively and I’ve heard this is from eating clover. Will this hurt my horse?

Answer:  Recently, there have been several reports of “slobbers” in horses. Slobbers, characterized by excessive salivation or drooling, is caused by a compound (slaframine) produced by the fungus Slafractonia leguminicola, which can be found on red clover.

The fungus can be identified by looking at the underside of red clover leaves, where it appears as small black dots (as though someone dotted the leaf with a felt tip marker). The fungus grows best in hot, humid conditions and can cause slobbers when eaten fresh in pasture or when consumed in dried hay.

Although unsightly, slobbers is not a concern for horses as long as they stay hydrated.

Written by Devon Catalano, M.S. and Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Fall Pasture Precautions

Fall Pasture PrecautionsHorse owners should take precautions when grazing pastures after the first killing frost. Frost damaged pastures can have higher concentrations of nonstructural carbohydrates, leading to an increase in the potential for founder and colic, especially for horses diagnosed with Equine Metabolic Syndrome, laminitis, obesity or Cushings.

To reduce the chances of adverse health effects, we recommended horse owners wait one week before turning horses back onto a pasture after the first killing frost.

Horses should be removed from a pasture when a majority of the forage is grazed down to 4″. The entire pasture should then be mowed to 4″ (since horses do not graze uniformly), drug to disperse manure piles and the horses should be rotated to a different pasture or housed in a drylot. This time of year (fall), horses will likely need to be kept in a drylot due to limited forage re-growth.

Ideally, owners will slowly transition horses back to hay diet (from a pasture diet) in preparation for winter feeding. We do not recommend over-wintering horses on pasture due to plant damage from digging, pawing, and hoof traffic.

Finally, ingestion of dried or wilted (but not fresh) maple leaves is associated with the toxicosis. Toxicosis normally occurs in the autumn when normal leaf fall occurs. Red blood cell damage has been reproduced in horses ingesting 1.5 to 3 pounds of dried leaves per 1,000 pounds of bodyweight.

Horses are the only species for which maple leaf toxicity has been reported. Horses are often depressed, lethargic, and anorexic with dark red/brown urine after the first day of ingestion. They may progress to going down with labored breathing and increased heart rate before death.

Horses should be fenced out of areas where wilted maple leaves are plentiful. Although dried leaves may remain toxic for 4 weeks, they are not generally believed to retain toxicity the following spring.

Written by Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.

Pasture Management – How to Prepare for Fall

Managing pasture can be a very important tool in controlling feeding cost for all livestock, including horses being kept on small acreages.  If pasture is going to provide a substantial amount of the required nutrition for a horse, it takes about 2-3 acres, per 1,100 pound adult horse.

Even with adequate acreage, weather conditions can limit pasture regrowth and decrease the amount of forage available.  Avoiding over-grazing is important for both the pasture and for the animals.   Keep the following in mind:

  1. Remove animals from the pasture when plants are grazed down to 3-4 inches in height. Grazing  too long and allowing animals to eat the grass off too close to the ground, will kill the grass and turn the pasture into a dirt lot where the only green plants are weeds, potentially requiring expensive renovation.   Also, if animals eat the grass too close to the ground on sandy ground, the risk of sand colic may increase.  Animals may also consume potentially toxic weeds if no other forage is available.
  2. If you have limited acreage, consider purchasing some temporary fencing so that you can rotate the pasture. The outer fencing should be a safe, permanent fencing.  You can cross fence the pastures with temporary fencing such as capped steel posts and appropriate electric wire.  By allowing the animals to graze one section, then moving them to another, total pasture yield can be increased substantially, helping to control total feed costs and improve pasture health.  Clip and drag the pastures after you pull the animals off to control weeds, parasites and flies.
  3. As pasture declines, you will need to adjust the amount of forage that is offered to maintain dry matter intake and nutrient intake. If the forage available is lower protein and lower energy than the pasture has been, you may have to adjust the concentrate portion of the diet. If you are using a ration balancer, you may need to move to the higher feeding rates.  If the higher feeding rates do not maintain Body Condition Score and Topline Score, you may need to switch to a different feed to allow higher feeding rates.  It is essential to monitor both Body Condition Score and Topline Score.
  4. Declining pasture quality can be a particularly serious issue for young growing horses, pregnant mares and senior horses.
  5. Make certain that fresh clean water is available at all times and that salt is available at all times. If you are not feeding a balanced feed or ration balancer, offer appropriate mineral free choice as well.
  6. If space is very limited, keep a dry lot area where animals can be fed and watered to prevent areas of pasture from being overgrazed.

Managing the pastures and selecting the right feeds as pastures change can help manage total yearly costs as well as improve animal health and condition.

Keep the Weed Seeds out of the National Parks, National Forests and National Grasslands

As horseback riders seek to take advantage of riding in the great outdoors, they need to be aware that National Parks, National Forests and National Grasslands will generally have a policy in place that any forage or feed that is brought into the area needs to be weed seed free.  Because there can be a hefty penalty, with fines up to $10,000 or 6 months of jail time,  it is highly advisable that riders check in advance the requirements of specific locations prior to bringing feed or hay into the location.

The North American Weed Management Association (NAWMA) has established the accepted standards for forage or unprocessed hay as well as for cubes and pellets made of forages.  The forage and unprocessed hay products will normally be identified by a bale tag or a twine of particular color.  The price for these products will normally be higher than for uncertified products.  Cubes and pellets will generally be identified by a certification tag indicating compliance with the North American Weed Free Forage Certification Program.

Riders can make a choice between long stem forage and pelleted or cubed products based on their feeding requirements and how the animals will be managed.

Commercially processed feed pellets and grain products that are processed by fine grinding along with heat treating and pelleting normally do not need to be certified as the processing is considered adequate to prevent the presence of viable weed seeds.

It is fairly common for riders to use both a certified forage/forage product and a commercially produced feed to meet the needs of animals while riding or packing into these great outdoor opportunities.  As always, free choice salt and fresh clean water needs to be a part of the feeding program.

The basic principle of not introducing any non-native or noxious weeds needs to be carefully implemented to preserve the wonderful riding opportunities that are available.

There are multiple options to consider as a trip is planned.  Various web sites can provide information about sources of forages in a given location.  The website www.trailmeister.com is a very useful resource as well as the state Crop Improvement Associations and the specific National Park, National Forest or National Grassland web sites.

Ask the Expert: Large Round-Bales

Question: We are having a hard time finding small-square bales and as a results, are going to start feeding round-bales. How many small square-bales are in a round-bale?

Answer: It depends on the weight of both the large and small-square bales. For example, if the round-bale weighs 1,000 pounds, then 20, 50-pound small-square bales would be equivalent to 1 round-bale. If the large round-bale weighs 1,200 pounds and the small-square bales weigh 40 pounds, then 30 small-square bales would be equivalent to 1 round-bale. It important to know the weight of hay bales both for feeding and economic purposes.
Also keep in mind storage and feeding losses associated with round-bales are usually higher compared to small-square bales. Especially if the round-bales are stored outside and fed without a hay feeder.

This article is reprinted with permission from Krishona Martinson, PhD, University of Minnesota. This and other horse nutrition articles can be found at http://www.extension.umn.edu/agriculture/horse/nutrition/.