The best way to avoid high shrink loss in bunker silos or drive-over piles is to first think safety, says Keith Bolsen, professor emeritus and forage management specialist with Kansas State University.
"If we make our silage infrastructure on a feedlot or dairy safer, it's also more efficient," says this silage-management guru. Overfilled pits, bunkers and piles are not only unsafe, they may not be packed as tightly as they could be. The feeding face is probably too large, feedout is difficult to manage, and the silage is more likely to be aerobically unstable in spring and summer.
"If we increase the density from 12 or 13 lbs of dry matter per cubic foot to 16 or 17, then we drop the apex (of most bunkers or piles) by 3 to 5'. Therefore, denser silage is also going to add to safety because we lowered the height. And it makes feedout more efficient – we just reduced the square feet of surface at feedout," Bolsen says.
Too many larger dairies put their entire corn silage harvest into one huge bunker or pile, he adds, and it might contain three or four different hybrids. That usually means the apex is probably higher than can be fed out safely or efficiently. But it also means that the quality of the silage will probably be much more variable than silage packed to a safe depth according to hybrid.
Or, instead of one large bunker or pile of corn silage, consider three smaller piles made from the first third, second third and last third of harvest, Bolsen suggests. Dangerous overhangs and silage avalanches will be things of the past, and nutritionists will have a better idea of what the nutritional profile will be for the silage in each bunker or pile.
Bolsen, who now does silage consulting for dairies and feedlots, recalls one dairy with a large shrink loss problem. "We got the dairy to go from a 40,000-ton pile to four 10,000-ton piles. Its estimated shrink went from about 23% to 14% in spite of the fact that the surface area more than doubled. We got the dairy’s silage team to increase density, pay attention to proper sealing – and their piles were safer."