As winter gives way to spring and summer, trees become greener and flowers bloom colorful and bright. Some people find themselves sneezing or coughing, develop congested nasal passages, and fight through watery eyes as a result of the abundant pollen or other environmental allergens. And like their human counterparts, horses can suffer from allergies too.

“Allergies are extremely common in horses,” said Katherine Williamson, DVM, a veterinarian with Purina Animal Nutrition. “It’s largely linked to management and their environment.”

Types of Allergies

Allergies have several potential causes and are categorized into one or more of four general classifications:

  • Insect hypersensitivity;
  • Contact allergies;
  • Inherited atopy (respiratory, dermatologic); and
  • Food allergies (although definitive documentation of food allergies in horses is uncommon).

Allergy Testing

Just about every horse gets itchy when flies and mosquitoes attack, despite our best efforts to reduce bites. Having a horse with pruritis (skin itching) and skin lesions might indicate allergies, but keep it mind it could also have a parasitic or fungal cause. For this reason, “it’s important to know exactly what you are dealing with,” Williamson said,

The primary treatment for allergies is avoidance of the offending allergen, but it can be difficult to detect specific allergens. Williamson gave some tips for narrowing the search for the problem’s cause (or causes):

  • Look for patterns of lesions on the body (what contacts the affected area?);
  • Consider if anything has changed (environment, bedding, topicals, feed, etc.); and
  • Use the process of elimination to try and determine possible causes.

While your veterinarian might treat your horse’s clinical signs, the cause might remain elusive and clinical signs might recur. Therefore, reliable diagnostic tools are needed to identify allergens.

Diagnosing Allergies

The intradermal skin test (IST) is the “gold standard” for allergen identification. Concentrated allergens are injected subcutaneously (under the skin), and the reactions are measured to determine what the horse is sensitive too. The primary drawback of IST is that results can be hard to interpret, and an experienced veterinarian is required. In addition, a patch of hair needs to be shaved, which is objectionable to some owners.

In the quest to find a better, easier, cheaper, and faster allergy test, commercial laboratories have offered serum allergy testing (SAT), which has become widely use in veterinary practice. For SAT, the veterinarian draws a blood sample, sends it to the lab, and awaits testing results. However, SAT also has major limitations, most notably that no commercial labs use horse-specific antibodies for testing, and results tend to be inconsistent. This method is also not useful for diagnosing food allergies. Consequently, test results can be difficult to interpret.

To diagnose food allergies, allergy specialists recommend an elimination diet. This involves removing all medications, supplements and concentrates, and putting the horse on a hay-only diet. These items can be reintroduced one at a time. If the horse shows no reaction, the item is likely not a culprit. A veterinarian and nutritionist should help oversee this process.

Take-Home Message

More research is essential for the development of a reliable allergy test in horses, Williamson said. The ISD remains the gold standard for allergy diagnosis (except food allergies). An elimination diet is currently the only reliable way to diagnose food allergies.

If you suspect your horse is suffering from allergies, take notes about everything he or she comes in contact with, from fly spray to bedding and everything in between, and make note of any reaction your horse has. Relay this information to your veterinarian so you can develop a proper plan of action.

Nettie Liburt, MS, PhD, PAS

The late spring rains have afforded our pastures exceptional growth into June in Virginia, when it is common to see pasture growth begin to slow about this time of year when temperatures escalate and rainfall diminishes. However, with summer quickly approaching, it is important to remember that it is very likely that soon pasture growth will decline and the “summer slump” will be here.

One of the best and easiest ways to reduce the negative effects of the summer slump is to maintain a high residue height in permanent, cool season perennial pastures during June, July, August, and into the fall. A high residue, or stubble height will allow forages to maintain their carbohydrate stores and regrow easier than with a short stubble height. Research has shown that what is above the soil is also reflected below the ground – in other words, the higher the stubble height, the deeper the roots, allowing the forages to scavenge for nutrients and water, possibly reducing the water-stress that could occur during the summer months when rainfall is often scarce. For most cool season perennial grasses, a residue height of 4” is ideal during the summer.

Most often in the mid-Atlantic region, pastures are comprised of cool season perennial forages – including, but not limited to, orchardgrass, bromegrass, fescues, timothy, ryegrass, birdsfoot trefoil, red and white clover. Commonly, these forages thrive in the cooler temperatures and shorter days, causing grazing livestock producers to be faced with slow-growing, unproductive pastures during the hot summer months.

Planting warm season annuals for grazing can be a way to mitigate the summer slump and keep animals off permanent, established cool season perennial pastures during a time they are susceptible to drought and heat stress. Sorghum x sudangrass, sudangrass, pearl millet, and a variety of warm season legumes have been shown to grow well in the mid-Atlantic region and provide high amount of yield to sustain grazing livestock. They are best fed through strip-grazing with a back fence, so livestock cannot return to where they just grazed and forage regrowth can be allowed. For the last grazing event of the season, a back fence is not needed as forage will not regrow after that. Warm season grasses need to be monitored closely during dry weather for nitrate levels, as nitrate poisoning could occur in grazing livestock. If toxic levels of nitrate is suspected, plant tissue samples can be sent away for evaluation.

Some research has shown that overseeding warm season annuals into cool season perennial pastures can be successful with careful management. While this is a relatively new area of study and practice in the mid-Atlantic and northeast region, overseeding cool season annuals into warm season perennial pastures has been done for decades in the southern United States. “Setting back” pastures through the use of a very low rate of herbicide or overgrazing pastures down to 1” and drilling warm season annual seed into existing pastures has been the most successful way of establishment; however, this management practice is still being widely investigated and has been shown to have variable results.

A warm season perennial pasture has been shown to be successful for grazing livestock during the summer months. Switchgrass, gammagrass, and some bluestems have been proven to grow well in our region and in the vegetative stage can provide a palatable forage for grazing livestock.

Commonly, warm season forages have a lower nutritive value than cool season. Depending on the species and class of livestock that is being grazed, nutritional supplementation may be necessary to provide the livestock with an adequate quality diet to meet their dietary needs.

Article adapted from Jessica Williamson, Penn State University Extension Forage Specialist

Here’s a question that looks simple but may be very hard to answer: Will your bulk tank be big enough in 5, 10 or 20 years? It’s also a question that applies to everything on the dairy. If you haven’t thought about this before, you might want to get started. Long-running industry trends point to numbers that could sneak up on you in a hurry.

In 2016, the average U.S. dairy had 223 cows, production was 22,774 pounds per cow, and total production per farm was 5,081,104 pounds per year. Just a decade ago those figures were 147 cows, 19,951 pounds per cow, and 2,932,797 total pounds per farm. Two decades ago they were 88 cows, 16,479 pounds, and 1,450,152 pounds.

Do you see what’s happening – and how quickly? Dairy herds are growing all the time, cows are becoming more productive all the time, and the result is total pounds of milk per farm is snowballing fast.

The table below shows how big that snowball could get.

Average growth in U.S. milk production per cow has been remarkably steady for the last decade: 282 pounds per year, which is the figure used in the projection table below.

Herd size growth is more complicated. The average gain has been 7.6 cows per year for the last decade, but it’s a figure that gets bigger each year as herd size goes up. On a percentage basis, growth has averaged 4.35 percent per year, which is what is used in the table.

Unless those two well-established trends change significantly, this shows roughly what the average U.S. dairy will look like in the years ahead.

From making just over 5 million pounds of milk per year (13,900 pounds per day) in 2016, in 10 years the average U.S. dairy figures to make about 8.7 million pounds (almost 24,000 pounds per day). In 20 years, it will be about 14.8 million pounds (40,700 pounds per day). Average production per cow will be over 28,000 pounds and average herd size will be over 500 cows.

Will you be ready for a farm that big?

Of course, not everyone who decides to stay in business that long will get to 500 cows. Some simply won’t want to. Others won’t be willing to take on the debt that is needed. Some won’t have enough land for forage production or nutrient disposal. Some won’t be able to find enough employees . . . or want to manage them.

Those who do grow will have to expand or improve every equipment, facility, and management aspect of the farm, because a dairy milking 500 cows is a much different beast than one milking 200.

So while the size of the bulk tank will be an issue, it may actually be the least of their worries.

Dennis Halladay – Hoard’s Dairyman


Hillary grew up in Botetourt County, VA. Since an early age of 6, Hillary has been active in the sheep and equine industries, showing both market lambs and Saddlebred horses. She participated on various equine, dairy, livestock judging, public speaking and Hippology teams through her high school 4-H and FFA chapters.

After graduating from Lord Botetourt High School in 2005, Hillary studied Biology at Emory and Henry College. Ultimately, her passion for horses helped shape her professional career. After college, Hillary began working for Botetourt Veterinary Hospital in Troutville, VA where she cared for small and large animals assisting with surgeries and patient recovery. She also worked for Flowing Spring Dairy and Eric Simmons Dairy as a Calf Caretaker.

In May of 2017, she joined the Augusta Cooperative team as their lead Equine Specialist. Currently, Hillary is responsible for all equine on-farm consultations, pasture management and nutritional programs.

In her spare time you can find Hillary active in the horse industry, showing Saddlebred horses, and improving her horsemanship skills through multiple disciplines such as dressage, hunter-jumper and ranch work. Hillary and her husband Willie, currently reside outside of Bridgewater, VA raising Dorset and Hampshire ewes, and showing market lambs with their two sons Liam (7) and Grady (4).

To visit with Hillary about any equine related needs, contact her at (540) 314-0928 or

Nominations are now being accepted for the 20th annual Innovative Dairy Farmer of the Year, an annual award co-sponsored by IDFA and Dairy Herd Management magazine. The winner will be honored at Dairy Forum 2018, January 21-24 at the J.W. Marriott Desert Springs in Desert Spring, Calif. Nominations must be submitted by August 25, 2017, and there is no fee to enter.

The call asks for nominations of active U.S. dairy farms that are improving on-farm efficiency through progressive management practices, production technologies and/or marketing approaches. Nominees will be judged on current methods as well as their positioning to meet future economic and business challenges.

The award recipient will receive an all-expenses-paid trip to Dairy Forum to attend a special presentation ceremony held during the program. (Winner will be responsible for all tax liabilities.) The person nominating the winner will receive complimentary registration to Dairy Forum.

In addition, the winning operation will be highlighted in the January 2018 issue of Dairy Herd Management.  Dairy Forum is widely recognized as the most important processor and producer conference of the year for the U.S. dairy industry. The 2017 event drew an impressive crowd of more than 1,100 industry participants.

Complete award criteria and a nomination form are available here.

Source: International Dairy Foods Association