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Extension > Horse Extension - Ask an Expert > June 2012

Thursday, June 7, 2012

What treats are ok for horses?

Q: I recently received a gift of two horses, a Percheron and a Quarter Horse. These two horses grew up eating anything, including banana and potato peels, even if they've started to decay. The original owner continues to bring these "treats" over for the horses. The horses are in good health, but are overweight. Is this good for them?

A: I'd suggest your neighbor bring more typical horse treats to the horses, such as apples, carrots, or manufactured horse treats. Anything novel or not normally found in the horses diet can cause problems. If the food is slightly decayed, the possibility of the horses ingesting mold or a mycotoxin is real and could be deadly, even in small amounts.

Equally important, the risk of laminitis and other metabolic issues is greater in over-weight horses (especially the breeds you have), so for the health of the horses, the treats should be eliminated. Once your horses weight is reduced, the treats, if given in small quantities, could be reintroduced.

If the well-intended original owner understands the risk, hopefully they'll be willing to bring different treats or stop all together.

By Krishona Martinson, PhD, University of Minnesota

Can I give rain barrel water to my horses?

Q: Rain barrels are commonly used to collect rainfall for use in watering ornamentals. What are your thoughts and concerns about using gutters and downspouts to catch rainwater in stock tanks with the goal of watering horses?

A: It is not recommend to use rain barrel water for human or pet consumption, or even for watering root crops and vegetables that will be consumed. There are potential issues with runoff from rooftops in terms of safe drinking water.

Atmospheric deposition of fine metals and particulates can be carried into roof runoff and possibly concentrated in the rain barrel water, as can petro-chemicals from shingles. New roofs can be especially prone to releasing particulates and chemicals into runoff, particularly when there hasn't been much rainfall for a while and the sun has been heating the rooftop.

In a setting where there may be birds roosting or resting on the rooftop, you can also get significant amounts of bird droppings in the runoff, and that can contain salmonella and other bacteria that can be potentially pathogenic (disease-causing).

By Barb Liukkonen, Water Resources Center, University of Minnesota

What can I do about off-label herbicide application?

Q: I made an application of Weed-B-Gone herbicide to my horse pasture. After application, I noticed it was labeled only for use on lawns (turf) and not horse pastures. When can I graze again?

A: It is extremely important to read the herbicide label prior to application; the label is the law. Herbicides are labeled for application to a specific site(s). Unfortunately, since Weed-B-Gone is not labeled for use in a pasture, there are two issues to consider, legality and safety.

You have made an "off-label" application, this is illegal. If the off-label application is reported to the Minnesota Department of Agriculture (MDA) (the agency charged with enforcing pesticide laws), an investigation would be opened, and there is the possibility of fines and penalties for the applicator. One benefit of involving the MDA is they take soil and plant samples to help determine when it is safe to graze. Because Weed-B-Gone is not labeled for pastures, the label does not include information on grazing restrictions.

The second issue is horse safety. If you choose not to report the off-label application, it is up to you to determine when it is safe to graze. To help determine this, look at the active and inert ingredients in the herbicide and see if they are found in any herbicides labeled for pasture use. Herbicides labeled for pasture use have information on grazing restrictions; this can be used to determine when to graze again, however, this will not ensure your pasture is safe to graze. You can also submit soil and plant samples to a laboratory for pesticide residue analysis. The herbicide manufacture might also have information related to off-label applications; a phone number is usually listed on the label.

Before a herbicide is purchased, the label should be thoroughly red and the applicator should ensure the desired application site is listed. Most herbicide labels are available online.

By Krishona Martinson, PhD, University of Minnesota

Is it safe to vaccinate my mare for strangles?

Q: My 22 year old mare had strangles two and a half years ago. I am wondering if it is safe to vaccinate her for strangles now.

A: Since your mare had strangles relatively recently, I would recommend having her antibody levels tested to see if they are still high. If they are 1,600 or higher, vaccination is unnecessary and use of vaccine could trigger an episode of purpura hemorrhagica.

Without testing, there is no way for sure to say if vaccination will be safe. Your veterinarian will be able to evaluate the antibody levels with a single blood test.

By Christie Ward, DVM, PhD, University of Minnesota

What is the ideal water temperature in winter?

Q: What is the ideal water temperature during the winter months?

A: Most adult horses weighing 1,000 pounds require a minimum of 10 to 12 gallons of water each day for their basic physiological needs. During winter months, water should be kept between 45 to 65°F to maximize consumption.

Waterers should be cleaned regularly, and clean, fresh water should always be available. If using a tank heater to warm water, inspect it carefully for worn wires or other damage, and check the water for electrical sensations or shocks. Snow or ice is not an adequate water source for horses.

By Marcia Hathaway, PhD, University of Minnesota

Should I blanket my horse?

Q: With winter coming, should I blanket my horse?

A: Blanketing a horse is necessary to reduce the effects of cold or inclement weather when:
  1. there is no shelter available during turnout periods and the temperatures or wind chill is below 5°F;
  2. there is a chance the horse will become wet (i.e. rain, ice, or freezing rain);
  3. the horse has had its winter coat clipped;
  4. the horse is very young or very old;
  5. the horse has not been acclimated to the cold (i.e. relocated from a southern climate); and
  6. the horse has a body condition score of 3 or less.
Keep in mind a horse will continue to develop a natural winter coat until late December; and blanketing before late December will decrease a horse's natural winter coat. Horses, given the opportunity to acclimate to cold temperature, often prefer and are better off outdoors.

By Marcia Hathaway, PhD, and Krishona Martinson, PhD, University of Minnesota

Are acorns toxic?

Q: The oak trees in my pasture have dropped thousands of acorns. I've read that acorns are toxic, what should I do?

A: Oak leaf buds and immature (green) acorn hulls are associated with horse toxicity. Mature (brown) acorns are not known to be toxic. If the acorns in your pasture are mature (brown), then there is no risk of toxicity. If the acorns are immature (green), then you must keep the horses off the pasture until the green acorns have been removed.

By Krishona Martinson, PhD, University of Minnesota

Are hybrid maples toxic?

Q: There are several hybrid maple trees being sold at Nurseries. The hybrids are half Silver Maple and half Red Maple. Have any studies been done on the toxicity of these hybrids to horses?

A: All trees in the maple family (Acer species) are considered toxic, including hybrids. However, the toxicity is only associated with wilted maple leaves (i.e. in the fall or after a storm). Assuming your horse has sufficient forage (hay or pasture), ingestion of enough wilted leaves to cause toxicity is unlikely, however, cases have occurred in the fall or during a drought when pasture forage is limited.

By Krishona Martinson, PhD, University of Minnesota

How do I determine selenium supplementation?

Q: I am looking for a good map detailing selenium soil levels in MN. I have clients ask about selenium supplementation and I worry about over supplementation.

A: We do not have a current map of MN soil selenium (Se) content. However, in general, the eastern half of the state has a bit more (about 80% of the feedstuffs contain somewhat greater than 0.1 ppm) Se than the western half (only 50% of the feedstuffs contain somewhat greater than 0.1 ppm).

Because the amounts of Se present in MN grown feedstuffs do not reliably meet nutritional requirements, adding Se from a mineral source, such as a ration balancer, is recommended. Most ration balancers for horses contain sufficient Se to meet the horses requirements without contribution from the hay, if fed at recommended levels. The maximum tolerance level for Se is three times the amount of Se recommended, or in the case of an 1,100 pound horse, 3 mg of Se per day. However, Se toxicity can be a real issue if that 'safe range' is exceeded.

This can easily occur if multiple Se containing supplements are used. Since the Se isn't why people usually purchase the supplement, they fail to account for total Se in the equine diet. Consequently, we tend to see more toxicity due to over supplementation than horse lacking Se. Signs of Se toxicity include dullness, roughness of coat, loss of hair, hoof soreness, stiffness and lameness

Specifically, some 'immune or energy booster' type supplements contain very high levels of Se. When multiple supplements are combined with a ration balancer, the result can be Se toxicity. This is especially the case with some owners who have the philosophy that if a little supplement is good, more is even better.

The take home message is to carefully read all supplement ingredient lists, especially if feeding multiple supplements, and calculate total daily Se intake, which should include forage, grain, supplement, and ration balancer Se concentrations. Work with an equine nutritionist if you are uncomfortable with these calculations.

By Marcia Hathaway, PhD, University of Minnesota

Why won't my horses lie down in the stalls?

Q: I use rubber mats over a concrete floor in my box stalls. I use only enough sawdust to absorb the urine and moisture in the stall and clean it out completely each day. I have never seen a horse lay down in the stall. Is there any reason to add more bedding in the stalls?

A: Horses need to lie down in order to get an adequate amount of deep sleep and will eventually, over weeks or months, become sleep deprived if they cannot or will not lie down for some reason. Opinions vary, but research on the subject suggests that relatively hard ground doesn't usually deter horses from lying down and getting enough sleep. Wet ground and deep mud will be a significant deterrent, however, as will a slippery surface.

If it were only one of your horses that never seemed to lie down, I would worry about musculoskeletal or lameness pain playing a role. Older or arthritic horses, for example, tend not to lie down as much as they should and go on to suffer sleep deprivation. In those cases, treatment of the pain is very helpful. If none of your horses lie down while in the barn, it makes me wonder whether they prefer to lay down outdoors for some reason. If you are worried, it is certainly worth running an experiment by bedding them more deeply for a time and looking for any change in their sleeping behavior.

By Christie Ward, DVM, University of Minnesota

Can horses get diseases from deer?

Q: Do you know if horses can get any diseases from deer? With the amount of snow we had this winter, the deer are eating hay out of the round bale feeder.

A: Unlike cattle and bison, which can contract tuberculosis (TB) from deer, horses seem to be less susceptible. I have never personally seen a case of TB in a horse in approximately 20 years as a practicing veterinarian. The risk exists, but is very low. There have been extremely rare reports of meningeal worm (Parelaphostrongylus tenuis); a parasite in deer feces that can migrate into the central nervous system of animals grazing contaminated pastures. Meningeal worm is a significant problem for sheep, goats, and camelids, but horses are minimally susceptible.

Some horse owners do prefer to fence the deer out of hay piles, which is basically impossible to do at a round bale feeder, unless horse access is also restricted. If the deer herd is large, fencing can reduce the economic impact of hay loss associate with deer feeding, which is likely of greater concern.

By Christie Ward, DVM, PhD, University of Minnesota

What is the vitamin content of grass hay?

Q: What is the vitamin content of grass hay? Specifically A, D, and E?

A: We are not aware of any published values for vitamins in grass hays or other forges, mostly because vitamins are generally only seen in low amounts or not at all in dried forages (hays). Plants do not actually contain vitamin A, but they do contain beta-carotene which is converted into vitamin A within the horse's gastrointestinal tract. However, beta-carotene isn't stable once the forage has been harvested, so levels decrease quickly (within weeks) until the amount left is insufficient to meet a horse's nutritional needs. Consequently, vitamin A should be supplemented when horses are fed harvested forages. Vitamin A is known for its role in night vision.

Vitamin D plays an important role in calcium absorption and similarly to vitamin A, the active form of vitamin D is not found in plants; however sun-dried forages tend to be good sources of the vitamin D precursor, which is later converted in the skin (after ultraviolet irradiation) and in the liver and kidney to the bioactive form. Hays tend to be good sources of the vitamin D precursor although there can be variations in the content of forages and the precursor will deteriorate over time in storage. Horses with normal sun exposure do not usually need additional Vitamin D supplementation.

Vitamin E is a best known for its antioxidant properties and is readily found in fresh forage, but levels quickly decline upon hay processing and storage. While extra vitamin E would have been stored in the liver of the horse that was consuming fresh forage during the summer, the levels are depleted in the fall when the horse is fed hay that has insufficient levels. Consequently, vitamin E should be supplemented if horses are fed a diet consisting mostly of dried hay. Generally, naturally derived sources of vitamin E have higher biological activity than do chemically synthesized sources.

By Krishona Martinson, PhD, and Marcia Hathaway, PhD, University of Minnesota

What is the harvest restriction on Roundup?

Q: Last fall, we did a 'burn down' on some hay ground using Roundup. We have a buyer for the hay, except the buyer heard that you should not feed hay that's been sprayed with Roundup, unless harvest was 6 weeks post application. Is this true and why?

A: There is usually a 4 day to 8 week harvest restriction on glyphosate (Roundup). Glyphosate is the active ingredient in Roundup and there are many formulations and companies that produce a glyphosate product. The range of 4 days to 8 weeks depends on the herbicide formulation; you must read the label to find this information.

Glyphosate is a slow acting herbicide that is translocated throughout the plant. The harvest restriction allows time for the herbicide to dissipate from the forage. If hay is harvested before the recommended harvest restriction, the harvest is 'off label', illegal, and not recommended. If the harvest restrictions were followed, then the hay is safe for horse or livestock consumption.

In Minnesota, we have seen both environmental (contaminated manure) and animal health issues with other herbicides when the grazing and harvest restrictions were not followed. It is important to read and following the entire herbicide label prior to making an application.

By Krishona Martinson, PhD, and Julie Wilson, DVM, University of Minnesota

Should hay be stemmy or soft?

Q: I was reading an online forum and they were discussing hay. A couple people posted how a horse needs stemmy, coarse hay to keep from colicing. They said soft, grassy hay will make them colic. I always thought soft, grassy hay was good for horses. What should I do?

A: There are numerous things that cause colic, but good quality hay is usually not one of them. Both stemmy and soft hays can be considered good quality; given both are free of dust, weeds, and mold, and should not affect the incidence of colic. Stemmy hay is usually more mature with less energy and nutrients and can be a good choice for adult, idle horses, or horses that need to lose weight. Softer hay is usually more immature and leafy with higher energy and nutrients levels. This hay is usually ideal for horses with a greater demand for energy like working, reproducing, and young, growing horses. In fact, a diet high in forage usually reduces the incidence of colic compared to diets high in grains.

Low quality hay that is dusty or moldy can increase the chance of colic. Overly coarse hay has been linked to impaction colics, and soft hay might cause colic if horses overindulge or a shift to a softer, more digestible hay is made abruptly. When making any feeding changes, the changes must be made slowly, this includes changing forage types.

If you are concerned about the incidence of colic, speak to your veterinarian and ensure your horse is in good health. Causes of colic can be unexplainable, but a diet high in consistent, quality forage should pose a limited risk of colic.

By Krishona Martinson, PhD, and Julie Wilson, DVM, University of Minnesota

How can I get a second opinion without hurting my vet's feelings?

Q: I want to get a second opinion but I don't want to make my veterinarian mad. Is this a good idea? How do I do it without hurting her feelings? My veterinarian is good at what she does but my horse has lots of issues.

A: Sometimes we all have gut feelings that indicate we are missing something. We probably need to listen to this voice; it is often recognizing subtle clues that we can't consciously identify. A second opinion is almost always a good idea in veterinary medicine as in human medicine. A fresh look or a new perspective often gives an answer or leads in a new direction that can solve the problem.

Most referral centers will ask if you want them to talk to your regular veterinarian or not, it is up to you. You can elect a middle ground where your veterinarian gets the information even if they did not know you were going to a specialist.

Ideally, however, your veterinarian is included and on board with the plan as that will enable the best care for your horse. You might try, "I have a feeling we are missing something and would like to expand our team. Do you have a recommendation for a specialist in this area?" If you meet reluctance, tell her how it impacts you, "I don't think I will sleep well until I pursue this and would like to do this with you as I trust you to help me sort out any conflicting advice and make sure I have all the medical history correct".

With your veterinarian involved, the horse benefits from the knowledge of his regular veterinarian along with the additional knowledge of the specialist, both before and after the appointment.

By Erin Malone, DVM, University of Minnesota

What are these bugs in the manure?

Q: There are small flying bugs that are turning horse manure into large areas of flattened mush. There are hundreds working on each pile. Do you know what they are?

A: Your "bugs" are actually small dung beetles or Aphodius haemorrhoidalis. We researched them in cow dung 15 years ago and found they were most abundant in spring, and tapered off in the fall. The ones you are seeing descended from a bountiful summer population and they are working on your horse's manure to build up nutrients for overwintering.

The beetles are actually beneficial; they spread out the manure, which speeds incorporation into the soil, and break up piles. It is possible that internal parasites eggs in the manure could become more spread out. However, any increase in parasite transmission would be minimal if you routinely deworm your horse(s).

By Roger Moon, PhD, University of Minnesota

Is alsike clover causing liver problems and sunburn in my horses?

Q: I have two clients whose horses are having liver problems. Some of the light colored horses also have signs of sunburn. Their pastures are filled with alsike clover. Is the alsike clover causing this?

A: Clovers (i.e. red, alsike, and white clover) are usually considered a beneficial pasture forage. However, alsike (and other clovers) is considered toxic when infected with the mold Cymodothea trifolii that causes Black Blotch disease in clovers and legumes (i.e. alfalfa). When mold infected clovers are ingested by horses, photosensitivity (sunburn) and liver damage can occur.

To determine if your clover has Black Blotch disease, go to the lowest, wettest area of the pasture, and look at the underside of the leaves on the lower 6 inches of the clover. Look for black or brown "blotches"; like a felt tipped marker was blotted on to the leaves. Look for this on all clover species in the pasture.

If you find the "blotches", rotate the horses off the pasture to a shaded area to reduce the exposure to sun and potential sunburn, mow the pasture or cut it for hay; the mold can not live on dried hay. After the pasture has had a chance to regrow and dry out, you can begin grazing again.

There is research being done on rabbits in Canada demonstrating that alsike clover not infected with mold did not cause toxicity, whereas alsike clover infected with the mold did. However, this research has not been done with horses. In our experience, mold infected clover has been present in pastures of horses with photosensitivity, and we have not seen photosensitive horses in pastures of clover or alfalfa uninfected with the mold.

Because clovers tend to grow in thick bunches that promote moisture retention (most molds thrive in humid conditions), if the problems persist, you may want to consider reducing or eliminating the clover from your pasture. Broadleaf herbicides (i.e. 2-4,D) will moderately control clovers and could be used to thin stands. All herbicides do have grazing restrictions so it's important to read the herbicide label and follow all directions. Fertilizing a grass/clover pasture with nitrogen will also help the grasses better compete with the clovers. Grasses need "applied" nitrogen while legumes (i.e. clovers and alfalfa) can fix it from the environment. Not fertilizing a grass-legume mixed pasture will heavily favor the legume species and over time, the legumes will become the dominant species in the pasture. Mowing and other practices to increase air flow to the pasture should also be done to reduce the amount of moisture retained in the thick stands of clover.

By M. Murphy, DVM, PhD; and K. Martinson, PhD; University of Minnesota

How do I transition my horse from baled hay to pasture?

Q: I have a question about our 24 year old Welsh Cob mare. We have kept her at a stable for the past 18 years. Now that we have our own farm, we are considering bringing her back to our farm to live with our other 3 equines. What concerns me is that our mare has lived the last 18 years in a paddock with very little grass and has been fed mostly baled hay. Our farm has lush pasture. I realize all horses need to be slowly acclimated to pasture in the spring or when they are introduced to a new pasture. She also had an episode of "gas" colic for the first and only time last summer. Other than the colic episode, she has never been sick or needed special treatment. What do you think?

A. You are correct, introducing her (and the other equines) slowly to the pasture is recommended (15 minutes the first day, increasing by 15 minutes each day until you reach 4-5 hours). Colic can occur for many reasons. Gas colic is often associated with feed changes or stress, so any steps you can take to minimize those two issues will be helpful if you decide to bring your mare to your farm. You might also want to consider deworming her before she goes out on the pasture to keep parasite burdens low.

Companionship will be the other key issue for her. If she is used to being with a group of herd mates, going into a group with strangers will be hard on her and consequently, her digestive tract. If she does not bond quickly with her new herd mates, keep you eyes open for a drop in appetite, depression, or manure changes that might signal an impending colic.

If she tends to be an easy keeper, you might also want to consider a grazing muzzle (or restricting grazing) to keep her from overeating in her new pasture.

Given her age, dental attention is wise, so speak to your veterinarian if she is due for her annual examination. Your veterinarian may have some other suggestions.

Finally, before turning horses out into a new pasture (regardless of the time of year), it is a good idea to check for poisonous plants and fence safety.

By Krishona Martinson, PhD, and Julia Wilson, DVM, University of Minnesota

Do mayflies carry Potomac horse fever (PHF)?

Q: There have been reported cases of Potomac Horse Fever (PHF) in my area (Isanti, MN). A local horse owner told me that mayflies are the vectors and that dead mayflies can still carry the disease. Is this true? Any information about PHF would be helpful.

A: Potomac horse fever (PHF), caused by Neorickettsia risticii, has been frequently diagnosed in case clusters in horses near waterways during the summer. The disease has been association with several vectors (hosts) including flukes living in water snails and aquatic insects including caddisflies, mayflies, damselflies, dragonflies, and stoneflies. The disease also appears to be carried in bats, birds and amphibians.

Clinical signs observed in horses with PHF include fever, anorexia (not eating), colic, depression, ileus (non-motile gastrointestinal tract), diarrhea, and laminitis (founder). Clinical signs and severity vary, but common to all cases is the manifestation of colitis (inflammation of the bowel). Clinical signs of the disease have been experimentally produced in horses 10-14 days after ingesting caddisflies.

In 2005, an outbreak of PHF was confirmed in Winona, MN and was linked to numerous dead mayflies that were positive for PHF. Horses are thought to accidentally ingest infected flukes from snails or infected insects while drinking and grazing, or from foraging or living in areas with high amounts of dead insect hosts. PHF cannot be spread horse to horse.

There is a killed vaccine for PHF, which may reduce the severity of illness but will not fully prevent infection. A veterinarian can perform tests on feces or blood to confirm PHF and most cases will respond to specific antibiotics and fluid therapy, however, some horses have died or have been euthanizes due to severe laminitis. The best treatment is prevention: reduce the contact your horse has with insect vectors by turning off lights in the evening that attract insects, turning off lights over outside water tanks, and removing dead insects from the barn. In MN, PHF is most often seen in isolated cases, but case clusters of PHF can occur given the wide distribution of rivers, lakes and ponds. Horse owners should ask their veterinarian about the frequency of PHF in their area to determine if the PHF vaccine is warranted. If so, the vaccine should be given in the late spring, and in high risk areas, boostered in late summer.

By Julia Wilson, DVM, University of Minnesota

Do fly predators work?

Q: I'd like to purchase fly predators, but do they work? I have 5 horses on a dry lot over the winter and on pasture in the spring, summer, and early fall. I do spread my barn manure on 1 of the 3 pastures. I then drag it and let it sit for a month, and then rotate to another pasture. Can I get my fly population down with predators?

A: First, do you know what kind(s) of flies are bothering your horses? How do the horses respond when attacked by the flies? This fact sheet illustrates the main kinds of flies we have in Minnesota.

Fly Predators kill house flies and stable flies, but not other kinds of flies. House flies and stable flies develop as maggots in moist, decomposing organic matter, such as accumulated horse manure, soiled (wet) bedding, and spoiled feed (hay or grain).

I recommend people do the following to prevent flies from building up to annoying levels:
  1. Dispose of accumulated waste in spring, so flies have little to develop in when weather warms in June.
  2. From June thru September, spread manure daily, keep bedding dry, and keep feed from getting wet and decomposing.
If you do all these things, then you will keep house and stable flies from developing on your farm. Adding Fly Predators may not help much.

You might also ask if the flies bothering your horses could be coming from neighbors? Flies will travel a half-mile easily, and flies could be coming from other stables or livestock facilities. If your neighbors are a source, then all you can do on your place is spray residual insecticides to kill the adult flies. Source reduction would require your neighbors to improve their debris management, and maybe Fly Predators would be of help there.

By Roger Moon, PhD, University of Minnesota Livestock Entomologist


What herbicide should I use to control hoary alyssum?

Q: We have been attempting to control weeds with frequent mowing, but now have seen some hoary alyssum and have decided to use an herbicide. We plan to use Forefront. However, upon reading the label and communications with the manufacturer, it appears that manure from horses grazing on Forefront treated pastures can only be spread in the treated pasture because it will kill broad-leaf plants. We have small paddocks and collect and compost our manure for use on our garden. It is my understanding that Forefront is very persistent and will not necessarily break down during the composting process. We also are located near a lake and designated wetland, so I am concerned about aquatic toxicity as well as impacts to amphibians. Upon review, it appeared that Stinger may be my best bet. Can you advise further?

A: Good for you for reading the label! You are correct that Forefront can persist in compost. However, if you follow the grazing restriction (time period after you apply the herbicide and before the horses can begin to graze again) on the label, you should not have these issues, but it's not guaranteed (chemical breakdown is dependent on weather and other conditions).

Stinger, Milestone, and Curtail (all commonly used herbicides for this situation) have the same potential issues (same family of herbicides). Even though these herbicides have no grazing restrictions (you should still check your specific label), we recommend at least a 7 day grazing restriction.

Hoary alyssum can be very difficult to control. The previously mentioned herbicides will work, but because of your specific issues, I'd recommend 2,4-D or Banvel. They may not give you as good of control, but you will not have the manure carry-over and compost issues to deal with. Since you can mow, I'd mow the pasture, wait about 10 -14 days (hope for some rain) and then spray the pasture. This will help achieve better control since the weeds will be younger/immature. Younger weeds are always easier to control versus mature weeds.

By Krishona Martinson, PhD, University of Minnesota


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