Health

Watch for downed cherry trees!

– Dean Kreager, Licking County Agriculture and Natural Resources Educator

Downed cherry trees pose a health risk for livestock.

Many people are aware of the danger when grazing animals consume wilted leaves from black cherry trees.  These leaves contain prussic acid which can result in cyanide poisoning.  If this sounds familiar, it is also the compound that causes toxicity issues with some warm season annuals after a frost.

Signs of toxicity can set in within 15 minutes of ingesting wilted leaves.  You may notice excess salivation, labored breathing, and convulsions.  Symptoms set in quickly so often you may find dead animals without seeing signs.  The lethal dose for cattle has been reported as 1.2 to 4.8 pounds of wilted black cherry leaves for a 1,200-pound cow and .18 to .72 pounds for a Continue reading Watch for downed cherry trees! →

The New World Screwworm: Texas is at Risk but what about Kentucky (and the Midwest)?

– Dr. Michelle Arnold, Rminant Extension Veterinarian, University of Kentucky

Figure 1: NWS larvae are pale with encircling black spines and sharp mouth hooks. Accessed from “Update on New World Screwworm 2025”; Gleeson Murphy; Parasitology, Chemistry, Analytical Services (PCAS), USDA, APHIS, Veterinary Services.

The New World screwworm (NWS, Cochliomyia hominivorax) is a blow fly that is native to the Western Hemisphere. Unlike most species of blow flies, adult female screwworms do not lay eggs on dead and decaying flesh. Instead, they lay eggs on living mammals at the borders of fresh wounds or at the edge of body orifices. The larvae (maggots) feed on the host’s living flesh, causing extensive damage by tearing at the host’s tissue with sharp mouth hooks (see Figure 1). The term “myiasis” is used to refer to the infestation of wounds by fly larvae/maggots. The wound will become larger and deeper as more eggs hatch and larvae feed on the living tissue, which may result in secondary infection and death if left untreated. New World screwworm is a pest that poses a dangerous and Continue reading The New World Screwworm: Texas is at Risk but what about Kentucky (and the Midwest)? →

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Managing Heat Stress in Cattle: Tips for Summer Success

– Dr. Katie VanValin, Assistant Extension Professor, University of Kentucky

Not the first choice to minimize heat stress.

Temperatures and humidity are on the rise, and this combination makes cattle more susceptible to complications from heat stress. Cattle have a thermoneutral zone which is a range of temperatures and humidity where they do not need to expend extra energy to maintain their body temperature. When environmental conditions are outside of this zone than cattle are susceptible to cold or heat stress. Heat stressed cattle will exhibit increased respiration and panting to try and stay cool. Heat stress results in decreased feed intake, milk production, and average daily gains. Some cattle are more susceptible to heat stress than others, and it is important to understand that heat stress compounds other conditions such as fescue toxicosis, or respiratory disease intensifying complications from these conditions. While we have little control over weather patterns, there are several steps that can be taken to minimize the negative impacts of heat stress on the herd.

Provide adequate shade
Shade is critically important for combatting heat stress in beef cattle. In grazing animals, care should Continue reading Managing Heat Stress in Cattle: Tips for Summer Success →

Help! I have hemp dogbane

– Christine Gelley, Agriculture and Natural Resources Educator, Noble County OSU Extension

Dogbane is poisonous to livestock.

Over the past couple of weeks, we’ve had several inquiries about hemp dogbane concerns and requests for help with keeping it under control in agricultural systems.

Both hemp dogbane and milkweed are easy to find this time of year and are often growing in the same habitat, which can be anywhere from roadsides, creek edges, open fields, forest edges, and flower beds. These two plants are related but have some distinct differences that can help landowners identify them and implement control measures when needed.

Similarities between the two plants include that they have creeping roots; leaves that appear on opposite sides of the stem; and they produce a milky sap. Differences include that young milkweed leaves have fine hairs and hemp dogbane are nearly hairless; milkweed stems are generally thick and green, but hemp dogbane stems are usually red to purple and thinner in comparison; hemp dogbane frequently branches in the top canopy, while milkweed will typically Continue reading Help! I have hemp dogbane →

Putting Poison Hemlock into Perspective (Again)

– Mark Loux and Stephanie Karhoff, CCA, OSU Extension

Figure 1: Once in bloom chemical control is difficult. Photo credit: Joe Boggs.

Poison hemlock is in full bloom across the state and continues to make the news, unfortunately. Poison hemlock is in the Apiaceae or parsley plant family, which also includes wild carrot (Queen Anne’s lace), wild parsnip, cow parsnip, and giant hogweed.

All these species share characteristics with poison hemlock to varying degrees and inhabit both disturbed and undisturbed sites such as roadsides, ditches, pastures, forest edges, and fence lines. Key identifying characteristics of poison hemlock include finely divided leaves (though lesser so than wild carrot, for which it is often confused), hollow stem, and . . .

Continue reading Putting Poison Hemlock into Perspective (Again)

Fly Control in Livestock for Summer

– Ted Wiseman, OSU Extension, Perry County (originally published in Farm and Dairy)

Horn flies feed on blood from the backs of cattle 20–40 times per day.

As summer temperatures rise, so does the pressure from biting and nuisance flies on livestock operations. According to university research, fly infestations cost U.S. producers an estimated $700 million to $1 billion annually in lost performance. With today’s strong livestock markets, minimizing these losses through effective fly control is more important than ever.

Understanding the Impact of Flies on Livestock
Flies reduce productivity by interfering with feeding, causing stress, and transmitting disease. The primary culprits include Continue reading Fly Control in Livestock for Summer →

When You’re Hot, You’re Hot!

– Dr. Les Anderson, Beef Extension Professor, University of Kentucky

Consumption of red clover can aid cattle during heat stress.

Last summer was a challenge for livestock. Kentucky recorded over 35 days with temperatures that exceeded 90⁰F and our temperature-humidity index was in the dangerous category for livestock for most of June and July. The impact of heat stress on livestock has been extensively studied over the last several decades. Heat stress reduces growth rate, can shorten gestation, increase lameness, disease, and death rates. Perhaps the most dramatic impact of heat stress is the marked reduction in reproductive efficiency.

Now is the perfect time to start planning to overcome heat stress. When I first got to UK, our Angus cows were involved in a variety of trials examining the impact of consuming endophyte-infected fescue on reproductive rate. For several years, these cows were synchronized for AI around June 10 and then exposed to a bull for 70 days. Cows consuming only endophyte-infected fescue had 55-62% pregnancy rates at the end of the breeding season. Similarly, Dr. Burris at Princeton demonstrated that the conception rate of cows decreased from 70% in early spring (April 1 – June 1) to 35% in the summer (June 20 – August 1) resulting in a pregnancy rate decrease from 90% to 58%. Heat stress reduces pregnancy rate by Continue reading When You’re Hot, You’re Hot! →

The Impact of Heat Stress and Fescue Toxicosis on Beef Cattle Reproduction

– Tyler Purvis, Les Anderson, Darrh Bullock, Kevin Laurent, Jeff Lehmkuhler, and Katie VanValin, University of Kentucky Animal and Food Sciences

Heifer experiencing heat stress resulting from fescue toxicosis.

Heat stress is a common problem facing beef-cattle producers throughout the United States, and in 2003 was estimated to cost the U.S. beef industry $369 million dollars annually. Heat stress occurs when an animal is creating and absorbing more heat than they can dissipate, which increases core temperature and physiological stress. Common symptoms of heat stress include increased respiration rates, panting, or standing in water such as ponds or puddles. Heat stress results in negative impacts on growth, health, and reproduction. Cattle can have reduced conception rates, growth rates, and milk production during the summer. During severe heat stress, conception rates can fall to 10%-20% or lower compared to 40%-60% conception rates observed in cooler months.

The severity of heat stress is impacted by both temperature and humidity. The temperature humidity index (THI), which combines temperature and humidity into one value, is used to evaluate the risk of heat stress. THI levels are classified as: normal (<75), alert (75-78), danger (79-83), and emergency (>84), according to the University of Nebraska Lincoln Beef Cattle Temperature Humidity Chart (Figure 1). This means that . . .

Continue reading The Impact of Heat Stress and Fescue Toxicosis on Beef Cattle Reproduction

An Update on Ticks and Tick-borne Disease in Ohio, plus the Buckeye Tick Test Lab

– Tim McDermott DVM, OSU Extension Educator, Franklin County (originally published in Farm and Dairy)

The Buckeye Tick Testing Lab at OSU is up and running.

It seems in Ohio it is never too early to start scouting animals for ticks. While we commonly think of summer as tick season, we actually see tick activity and positive detections of tick-borne disease all 12 months of the year in Ohio. One of the ticks of the biggest concern impacting livestock, especially cattle, in Ohio is the invasive Longhorned Tick(LHT). This tick was first discovered in Ohio on a dog in Gallia County in 2020 and has rapidly increased its range in Ohio since then. As of the beginning of 2024 we had positively identified LHT in 11 counties in Ohio including Franklin, Delaware, Ross, Gallia, Vinton, Jackson, Athens, Morgan, Monroe, Belmont, and Guernsey county. Since that point we have added Pike, Lawrence, Noble, Coshocton, Wayne, Muskingum, Washington, and Licking bringing our total up to 19 affected counties. We anticipate adding to that list in 2025.

The Longhorned tick can be a tremendous problem for cattle being able to cause mortality through blood feeding as well as through the Continue reading An Update on Ticks and Tick-borne Disease in Ohio, plus the Buckeye Tick Test Lab →

Concerning parasites, are you controlling what you think you are controlling?

– Dr. Jeff Lehmkuhler, PhD, PAS, University of Kentucky

Available since the ’80’s, is it still effective?

Spring is my favorite time of the year as the flowers bloom, turkeys begin gobbling and the grass takes off. The grass has jumped quickly with the rain and warmer temperatures the last few days. I think we all can agree there is some joy in knowing when the last bale of hay is fed for the winter. However, with spring comes many management challenges beef operations must tackle. These include grass tetany, frothy bloat, dystocia, and tetanus to name a few. During this time frame is always when both internal and external parasites become more prevalent. Many beef operations will apply some level of management to control parasites that can rob nutrients from the cattle. This begs the question “Are you controlling what you think you are controlling?”

During the spring and fall of 2023, University of Kentucky Cooperative Extension Agriculture & Natural Resource county ANR Agents, Kentucky Beef Network facilitators as well as Dr. Arnold and I set out to assess the prevalence of internal parasites in Kentucky beef herds. Additionally, many of the anthelmintics or deworming products have been on the market for decades (1960’s for levamisole and 1980’s for ivermectin), so we wanted to Continue reading Concerning parasites, are you controlling what you think you are controlling? →

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