Each year, as spring approaches and hay stocks begin to dwindle, hay prices increase and some year-old stored hay comes on the market.
Producers should test before buying, says Barry Yaremcio, beef and forage specialist with Alberta Agriculture and Rural Development. “While the feed may have initially been put up very well, sitting in the yard or field for an extra year has likely changed the feeding outlook of the forage.”
He says hay is perishable and deteriorates when exposed to weather. Ninety days after cutting, the vitamin precursors lose strength and animals will require supplementation. The fat-soluble vitamins A, D and E are the first nutrients to oxidize.
“Injecting or feeding vitamins 90 days after animals are taken off fresh forage is necessary until they are put back on pasture the following spring,” Yaremcio says.
Bales that are stored under a shed, covered or wrapped in plastic do not deteriorate over the winter as much as hay stored outdoors. A feed test in the spring, compared to the results from the previous fall, would likely show the protein, fibre (energy) and mineral content of the hay stored under cover to be very similar. This is not the case for hay that is stored outdoors, uncovered and on the ground.
“In a six-foot-diameter round bale, 27 per cent of the bale weight is found in the outer five inches of the bale,” says Yaremcio. “For every inch of rain, 180 pounds of water will land on the bale. Some will run off, but some will enter the bale. When the exterior of the bale is rain soaked and is exposed to weather, it rots.”
More weather damage occurs to legume hay compared to grass hay. Applying twine at four-inch spacing reduces moisture entry into the bale compared to bales with twine at eight-inch spacing. Net-wrapped bales shed rain better and have less damage than bales tied with twine. Bales wrapped with solid plastic have the least amount of damage. A denser or tighter bale sheds more water than a looser bale. As well as reduced bale weights, moulds and bacteria can use up the best nutrients in a bale. The soluble proteins and highly digestible sugars are consumed leaving off-coloured mouldy feed, which reduces the feeding quality. Also, weather damage can increase the indigestible fibre levels in hay by five per cent or more and reduce energy levels by similar amounts.
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“Because of possible quality reduction, the best advice is to feed test – even if you see last year’s feed test results, retest the hay before purchasing and/or feeding,” says Yaremcio. “For that year-old hay, when exposed to the elements, damage occurs. Digestibility of the outer five inches of the bale is reduced by 20 per cent. Overall forage digestibility in a round bale is reduced by 10 per cent. If the hay is kept over for a second year, additional weight loss occurs and digestibility is reduced even further. In some situations, this older hay could be no better than feeding cereal straw.”
If you expect this older feed will be the majority of this year’s feeding program, protein and energy supplementation will likely be required to meet animal requirements. As a guideline, hay made in 2012 should not be more than 25 to 30 per cent of the forage in the ration for cows in early to mid-pregnancy, and 15 to 20 per cent in late pregnancy. Depending on quality, year-old hay may not be suitable to include in lactating cow or newly weaned calf rations.