Published June, 2011

Central Kentucky is finally getting a break after two months of heavy rain, according to University of Kentucky (UK) staff meteorologist Michael Mathews, and horse owners should now assess the lingering effects of all that wet weather.

April in the Commonwealth was the wettest ever, nearly doubling the previous record set in 1972. At 12.04 inches, rainfall totals were 7.7 inches above normal. The sustained heavy rains during the last three weeks of April flowed into May, which also had above-normal rainfall of 6.8 to 7 inches. Meteorologists predict June, July, and August rainfall to be normal, with temperatures below normal, except for predicted temperatures slightly above normal in June.

"The rain has been good for pastures and they are growing vigorously," said Ray Smith, PhD, professor and forage extension specialist at UK. "The downside is that it has been too wet to spray weeds. Pastures with a high-stocking density may be torn up and may have some decline. But moderately grazed, well-drained pastures have loved the rain and cooler weather."

Smith said most people missed the ideal window (March) for planting cool season grasses (Kentucky Bluegrass, orchardgrass) because of weather events, and they will now have to wait until fall.

"Many were not able to seed or overseed last fall because of the drought, so now there may be bare spots where weeds can grow," Smith said. "In preparation for seeding in September, spray weeds two months in advance but be sure to check herbicide labels for specific guidelines for application."

He said weeds to look for include plantain, dock, poison hemlock, crabgrass, and foxtail.

Another missed opportunity due to the rainfall was harvesting high-quality hay in mid-May, Smith said. While farmers still have a good window to cut and dry hay, the quality and digestibility will be lower because the hay is overly mature. Subsequent cuttings' quality will depend on weather patterns,but Smith said if there is adequate rain, farmers should have a good second cutting.

"Because of the late cutting, look closely at the nutritional quality," Smith said. "Any hay cut during May could have mold and dust issues. And hay that was rained on after cutting will have nutrient loss."

Smith believes that hay fields prepared and sprayed out to plant corn and beans might lead to hay shortages.

Managing environmental systems after heavy rain is also important, according to Steve Higgins, PhD, director of environmental compliance at UK's Agricultural Experiment Station.

"Part of good horse management is ensuring that environmental systems are being addressed properly," Higgins said. "Some of the basic issues for horse people are to practice rotational grazing, create traffic pads around gates and entrances, feed off the ground, drain water away from buildings, and encourage riparian (river bank) areas."

The recent wet weather can also cause management issues. According to Fernanda Camargo, DVM, PhD, equine extension professor at UK, and Laurie Lawrence, PhD, professor in the department of animal and food sciences at UK, "horsing around" on muddy ground can cause a horse to fall, bow a tendon, or pop a splint. To prevent injury, Camargo and Lawrence advise caution on slippery slopes and with young horses.

UK Cooperative Extension Service's "Horses and Rain" offers more management tips, including:

• To prevent skin problems that crop up in rainy weather, groom thoroughly and often, which gives the coat and skin time to air out and dry.
• Have shelter available, or consider bringing your horse in for part of the day.
• Review your vaccination schedule with your veterinarian, since standing water can lead to a high incidence of mosquito-borne illnesses such as Eastern and Western equine encephalomyelitis and West Nile virus.
• Rodents seek dry shelter during floods, often moving into barns and houses. Rodents can carry leptospirosis and should be exterminated. Never dispose of rodent carcasses by throwing them into pastures or anywhere near horses. Doing so can attract varmint such as opossums, which can transmit equine protozoal myeloencephalitis (EPM).
• Floodwaters also carry garbage such as baling twine, broken bottles, plastic bags, and soda bottles. Remove these potentially dangerous items from pastures promptly.

The Horse Owner's Post-Rain Checklist

• Watch bare spots to prevent a profusion of weeds in fields that were not reseeded in March because of the weather. Seed or overseed during fall.
• Check the quality of first-cutting hay closely, which could have low digestibility, mold, and dust.
• Review your stocking rate to eliminate stress on pasture grasses.
• Limit erosion by placing gates, waterers, feeders, and shelter on high ground.
• Use a sacrifice drylot.
• Groom often to prevent fungal infections.
• Make sure vaccinations are up-to-date.
• Exterminate rats and mice, which might move into barns and houses during rainy periods.
• Clear debris that floodwaters carry into pastures.
• Remove any rotten hay or vegetation, which could cause botulism (rare disease caused by a neurotoxin produced by the bacterium)
• Review your environmental systems, and develop your water quality plan as required by law. (Visit www.ca.uky.edu/awqa for a tool to help with self-certification.)

Karin Pekarchik is an editorial officer in Agricultural Communications Services.