In part one of this two part series, we covered the cost of forage shrink on farms and the areas of concern. In part two we’ll cover solutions that you can implement on your farm to control these losses.
Four key areas were examined at the recent “Shrink your Feed Shrink” programs put on by the Michigan State University Extension Dairy Team. The areas of impact include: Harvest, Packing, Covering, and Feed-out.
Harvest losses can be reduced by following some basic principles. First, we need to maintain equipment so that it is functioning properly. For instance a rusty, worn chute on a silage harvester will affect how well it will blow the silage into wagons. If some of the silage drops outside of the wagons due to equipment maintenance, or high winds, we have just experienced forage shrink. The other loss at harvest is related to the quality of the silage we harvest. It is recommended that silage be harvested at 65-70 percent moisture for bunkers and bags, and 60-65 percent moisture for uprights. Harvesting at the correct moisture will help improve packing, fermentation and digestibility. All of these will help reduce forage shrink.
Packing losses occur when we spend too little time packing, especially while filling, and also when we have too little weight on the tractor we are using to pack the silage. We should be aiming for densities of 15 to 17 lb./DM/ft3 average (bottom, middle, tops and sides). We can achieve these goals by increasing weight or slowing down. One easy way to calculate the tons/hr. that you can effectively pack is: tons/hour = tractor weight/800.
Shrink can also occur due to how we cover the pile, or not covering the pile at all. Covers should be applied to bunkers and piles immediately after filling. Tires to hold down the pile should be touching and doubled at the edges and seams. Seams should be overlapped. One producer that spoke at the “Shrink your Feed Shrink” program indicated that he overlapped the plastic and then rolled it together to ensure that water could not enter the pile. Producers receive an 8:1 return on their investment when they cover their bunker silos. Another product available to producers is Oxygen Barrier plastic. This plastic covering is installed under your traditional plastic and significantly reduces spoilage by keeping oxygen out of the silage. One sheet of Oxygen Barrier plastic is equivalent to 60 sheets of regular silage plastic cover, in its oxygen exclusion. Most oxygen barrier plastics are thin and require a sheet of 5-6 ml. plastic on top.