By Kristen M. Janicki
How to make hay changes safely and effectively
“Thou shalt make all feed changes gradually,” could be listed as one of the 10 commandments of horse ownership. The National Research Council’s Nutrient Requirements of Horses: Sixth Revised Edition (2007) states that owners should make any changes in the amount or form of a horse’s feed—grains, concentrates, hay, and pasture—gradually due to the animal’s sensitive digestive system. This reduces risk of colic due to digestive upset. But sometimes things don’t work out as planned and you need to make a quick switch. Let’s look at scenarios that might call for a sudden change in hay type and how to make the shift safely and effectively.
Dwindling Supply & Changing Demand
Weather plays a critical role in hay production. Each grass and legume species requires a specific temperature and precipitation range for optimum growth. For example, orchardgrass grows best at soil temperatures of 50-65 degrees Fahrenheit with about 18 inches of annual rainfall. In years when growing conditions for plants are challenging, horse owners could find the hay supply drastically reduced. The most common weather-related reason for hay shortages across the world? Drought.
Drought occurs when a high-pressure system locks in over a geographical area, causing below-normal amounts of precipitation. The worst drought in U.S. history, known as the Dust Bowl, caused major agricultural damage in the 1930s. More recently, in New South Wales, Australia, a severe drought with some of the lowest rainfalls on record caused hay prices to more than double, leaving farmers unable to feed their livestock.
Too much rainfall also affects hay production. “Wet weather at harvest can reduce quality by enabling mold growth and dust to form in the hay,” says Christine O’Reilly, MS, forage and grazing specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).
Basic supply and demand also impact hay availability. “If small square bales are the desired product, one may have difficulty locating them in areas where farmers have switched to (producing) round bales, as they are less labor-intensive to produce,” says Alison Moore, DVM, DVSc, Dipl. ACVIM, ACVSMR, lead veterinarian of Animal Health and Welfare with OMAFRA.
If hay ships from Ontario, for instance, to other parts of Canada or areas of the United States that might be experiencing a drought, Ontario’s hay supply will dwindle. Basic economics tells us that when there’s a low supply of a commodity, there’s increased demand leading to inflated prices. If hay quality becomes a problem, more people switch to alternative forages, reducing baled-hay demand.
Even with a plentiful hay supply, some health conditions might necessitate a change in hay type. For instance, switching to alfalfa could help a horse with gastric ulcers. In fact, researchers have shown that feeding horses alfalfa hay could provide acid-buffering support by increasing stomach pH. Injuries, especially those to the teeth or jaw, can negatively affect a horse or pony’s ability to chew long-stemmed hay properly, necessitating a processed, chopped hay; hay cubes; or pellets. Then there are the unavoidable natural changes that warrant a forage change. As horses and ponies age, they lose the ability to chew and digest long-stemmed forage as easily as their younger counterparts. That’s because after about age 20 their teeth stop erupting and can wear down to the gumline. Cheek teeth surfaces flatten and smooth out, diminishing their ability to chew forage properly. Some older horses might even lose teeth or suffer from dental disease, affecting their ability to chew, as well.
Although more typical when making rapid changes in grain or concentrates, colic risk increases with changes in hay type, too. Among all the feed changes studied in horses, those to hay type remain the most significant. Based on data from practicing veterinarians in Texas, Noah Cohen, VMD, MPH, PhD, Dipl. ACVIM-LA, director of the Equine Infectious Disease Laboratory at the Texas A&M University College of Veterinary Medicine & Biomedical Sciences, in College Station, says horses experiencing a change in hay type were almost 10 times more likely to colic in a study of 1,030 colic cases than equal numbers of controls. The most common colic causes associated with changes in hay type include impaction or changes in microflora altering pH or volatile fatty acid production, he says.
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