OLDS, Alta. — Quality losses are inevitable in hay left to sit outside in fields over winter.
But producers can take steps to better protect them, said Barry Yaremcio, beef and forage specialist at Alberta Agriculture.
“You need to do something to protect those bales from weather to optimize the use of that forage, especially if you have got carryover,” said Yaremcio.
Rain and winter weathering reduces protein content and digestibility, he said at a recent feed workshop held in Olds.
“Feed intake is reduced when hay is stored outside. On average, for a beef cow you will lose half a pound per day on intake for hay that is not stored and protected,” he said.
Precipitation damage cannot be controlled but if rain comes when the hay is at 20 to25 percent moisture, a lot of nutrients can be lost. Half the crop could be lost if 70 millimetres of rain hits the hay within a day or two of baling.
Hay left outside will lose dry matter content because of damage to the outside of the bale.
Ten centimetres of spoilage on the outside of a bale could result in 300 pounds of wasted feed.
If using outdoor storage, producers should not stack bales, he said. As well, they should leave 15 to 20 cm of space between bales in single rows, facing prevailing winds so air can better circulate.
“Stacking in a pyramid is probably the worst way you can store your hay because the moisture comes off the top bale and goes down, and anywhere the bales touch is where you get the damage,” he said.
Yaremcio also recommends against stacking bales in a mushroom style because the bottom bale absorbs all the moisture.
Net wraps improve the bales’ long-term storability and help to better shed water.
Plastic covers can be as effective as a shed if the plastic stays in place and there is no damage or holes caused by animals.
Some people close both ends of the plastic. That causes overheating, and as temperatures rise in the plastic, moisture migrates out of the bales.
Spoilage can occur in various forms and in some cases could make livestock sick. Producers are encouraged to have the feed tested.
Ergot and mycotoxins have been a problem the last few years, caused by cool, cloudy weather during flowering of open pollinating cereals and grasses.
Long-term effects on livestock health include feed refusal, digestive upsets, pneumonia like symptoms, hoof problems or even death.
“If you want to prevent any problems with ergot or toxicity, you need to cut before those plants are pollinated,” he said.
There are 40 types of alkaloids in ergot bodies and four different strains are found in Western Canada. Recent tests find toxicity levels are 2.5 to three times higher than what is being reported in the U.S.
Animal tolerance to alkaloids can vary and it could take as long as six weeks for symptoms to appear. If producers notice symptoms in their livestock, they need to remove the feed and offer something else.
The high estrogen content in alkaloids can cause temporary infertility in cows because it acts like a form of birth control.
Hoofs can come off and never properly repair themselves.
Outdated feed standards once recommended no more than one kernel of ergot-infected kernels in 1,000 should be used as feed. Today’s standards recommend one kernel in a five-gallon pail as the limit.
In 2014, 964 samples were submitted for testing. In 500 of those samples, more than half had 200 parts per million of ergot contamination. In 2015 the analysis showed about 40 percent of the samples were contaminated.
Moulds and mycotoxins from fusarium graminearum produce a pinkish white fungal growth. These can cause cattle to refuse feed and also cause vomiting and diarrhea.
Symptoms are more severe in monogastric animals.
Pigs can only handle one p.p.m. but yearling heifers can digest up to 37 p.p.m.
These toxins can affect reproduction.
Two of the mycotoxins formed within fusarium can destroy the epithelial tissue in cattle rumen so the animal is incapable of efficiently absorbing nutrients.
Suppression of bone marrow development can also occur and skin disorders like photosensitivity may appear. It resembles a sunburn around the eyes and udders.
Aspergillum is a white mould on heated or tough grain or on hay that was baled tough. It is more of a nuisance and is a naturally occurring bacterium in the soil.
Penicillium forms a green- or blue-green mould that is found on grain and can cause abortions, retained placentas and reduced fertility.