Bale grazing is a common winter feeding practice but how much forage are those cows leaving behind? Alberta Agriculture and Food recently shared results from one trial that examined that question.
The Lakeland Agricultural Research Association (LARA) measured waste from bale grazing over four winters, from 2008 through 2011. The study was done using the same cow herd in Bonnyville, Alta. Each fall they laid out tarps in the field, weighed round bales, and centred the bales on the tarps. The bales were fescue-alfalfa. Some were placed on their sides and others on their ends.
Cattle grazed the bales over the winter, usually in January and February, said Alyssa Krone, forage and livestock specialist with LARA. Krone said the cows were turned out to the bale at about 9 a.m. and moved off the bales around 4 p.m. each day.
“On really cold days, the cattle were left in the bales overnight until the weather changed,” she said. “This limited access system could have impacted the amount of waste produced.”
Each spring, they collected and weighed residue from the tarp. Krone said they did remove large piles of manure before weighing the residue. They also collected samples so they could estimate how much of the residue was forage and how much was manure. About 20 per cent of those samples were manure, Krone said, so about 20 per cent of what looked like feed waste in the field was actually manure.
“The general trend was to see less waste in bales on their sides than on end during the project, but we only found a significant difference in 2011,” said Krone.
That year, side-placed bales saw a seven-per cent waste versus 16 per cent in the end-placed bales. The four-year waste average for end-placed bales was steady at just under 16 per cent. Winters with more snow saw more waste.
Krone said the wasted feed quality was also lower than the initial feed quality.
“This could indicate that it was lower-quality feed being wasted, although weathering could have also contributed to quality loss.”
For more information on the trial, contact Alyssa Krone at 780-826-7260.