“Silos go to Preschool,” “Grown Men Get Paid to Work with Playdough,” “Where Playdough and Silo Meet” or “Dairy Farms are Future Site of World Record Playdough Production” might have set the stage for what was to come.
But no, “Covering Bunker Silos” was the truly uninspired title for the coolest presentation at the 14th Tri-State Dairy Nutrition Conference last week.
Persistent challenge. Minimizing loss of feed and feed quality in silos is a persistent challenge for cattle producers.
Whether ensiling in uprights, bunkers or piles, open surfaces invite spoilage.
Typical feed dry matter and quality losses in uncovered silages can reach 50 percent in the top 3 feet of silage.
Even in silages carefully covered with plastic weighted down by tires, losses can reach 25 percent.
Plastic drawbacks. While plastic coverings are currently the best technology to minimize forage losses, there are drawbacks.
Plastic, tires, labor to cover and uncover silage are costly. Plastic disposal and tire management are problematic.
Ideal covers. Ideally, a covering would be easy to apply, allow little or no waste, be edible (no uncovering or separating spoiled forages) and have feed value.
Many potential covers have been studied, but since no one is using lime, earth, candy, molasses, apple pulp, composted manure solids (most definitely does not satisfy the “edible” requirement) or peanut butter, the success rate is obviously low.
Creativity. Fortunately, Larry Berger, animal scientist at the University of Illinois has a creative wife and children.
She had made some homemade playdough that he came across one day. Knowing it had been made several months earlier, he noticed that it was still pliable.
Hmm … Several years, graduate students and research projects later, what was originally a kid’s playdough is close to becoming an edible, effective silo covering.
Objectives. Since most farms do not have an adequate supply of graduate students (read as “cheap labor”) to trowel on a silo covering, recent studies have developed the ingredients and process to achieve Berger’s stated objectives:
1) Provide effective protection.
2) Be edible.
3) Provide essential nutrients.
4) Be palatable.
5) Be easy to apply.
6) Be cost effective.
Process. The current process involves a mix including ground wheat, salt and water which is sprayed 0.5 to 0.75 inches thick on the pile.
This mix has the advantage of bonding with the silage, eliminating the air interface still present on a pile covered with plastic.
The salt in the mix also helps preserve the top layer of silage.
The mix is then sealed with wax or giant sheets of food-grade wax paper. This helps stabilize the covering and waterproofs the pile.
With the objective of developing this process into a job that can be done either by a custom operator or the farm, initial mixing of the liquid dough would be done in the farm’s feed mixer and loaded into a pump that would spray it over the pile.
Promising. This process is looking very promising.
Studies have graduated from little 12-by-6-by-6 to 24-by-7-by-4 silos.
Dry matter (spoiled silage removed by hand) recovered and fed from silos treated with the edible covering and either paraffin or wax paper was 23 percent and 15 percent greater, respectively, than dry matter recovered from a control pile covered with plastic and 2 inches of soil.
Salt and the other nutrients in the covering can be worked into the dairy’s ration without negatively impacting feed intake.
The objective is that their cost be recovered as feed value.
Potential solution. While all the wrinkles have yet to be ironed out, this is a potential win-win for dairymen, cows and environmental concerns.
That is, if you’re not selling silo plastic or split tires on the side.
(The author is the northeast Ohio district dairy specialist with OSU Extension. Send comments or questions in care of Farm and Dairy, P.O. Box 38, Salem, OH 44460.)