Adapted by Jennifer Heguy, UCCE Dairy Advisor, Deanne Meyer, Livestock Waste Management Specialist; Noelia Silva-del-Rio, Dairy Production Medicine Specialist
Current California Silage Storage Practices. In 2013, a survey on Corn Silage Management Practices was mailed to dairies in the San Joaquin Valley. A total of 160 producers replied to the survey. Select responses are summarized below.
Type of Silage Structures. Silage is primarily stored in wedge (34%) and drive-over piles (32%) with far fewer structures consisting of bunkers (7%) or bags (6%). Twenty-one percent of dairies used a combination of structures to store silage, most often a bag with a previously mentioned structure type. In terms of future storage trends, roughly a third of surveyed producers expressed interest in moving towards drive-over piles, and the overwhelming consensus was that bunker silos are a thing of the past (84% would not use bunkers in the future).
Width and Depth of the Face Removed. Daily, the entire width of the face was removed in 54% of dairies, but only half of these dairies removed at least 12 inches of depth. Of those dairies removing half of the face daily (15%), less than half removed the recommended 12 inches of depth. These numbers indicate that current practice is not to size silage structures according to feed-out needs. Sizing of structures appears to be a function of physical space available to store silage. In the same survey, 56% of dairies expressed interest in increasing their silage storage area.
Thinking about Changing Silage Structure Type? A few key questions should be evaluated, as each of these may impact silage quality and spoilage.
- How many animals are you currently feeding, and will this number be increasing or decreasing?
- Do you currently move across the entire silage face daily, with a depth of at least 12 inches?
- What does surface spoilage look like (top and sides)?
- What is your current maximum height, and can your front-end loader/defacer reach the top?
Changing structure type or physical layout will likely impact exposed surface area and modify the opportunity for spoilage. In a 2011 study, exposed silage face surface area was evaluated. In general, drive-over piles were larger than wedge piles which were larger than bunkers. Bagged silage was not evaluated, but would lend to the smallest surface area of the storage options. Carefully evaluate existing face stability and feed-out depths before modifying storage structure design. If you currently do not move across the face daily, or you notice that lack of depth removal is causing a decrease in feed quality, moving from a smaller working face to something larger likely will not improve your feeding situation.
Strengths and Weaknesses of Types of Silage Structures. Each of the different structure types has strengths and weaknesses, and not all are discussed here. Drive-over piles have potential for decreased height and increased packing density on the sides, but as mentioned above, have large exposed faces that may be difficult to move across in a timely manner and require large amounts of plastic. Wedge piles are intermediate in exposed face, require less plastic than drive-overs, but safety concerns both while building and feeding from the pile should be considered. Bunkers make for the least flexible storage option with a fixed width and height, a likely reason bunker popularity has declined. Bags are easy to feed from and boast the smallest exposed surface area, but large amounts of plastic and a potentially large land footprint, combined with the need to carefully monitor the plastic for damage (low packing density allows air to readily infiltrate the silage mass when rips/holes occur) should be considered.
Take-Home Thoughts
What works for your neighbor, might not be the best fit for your feeding needs. There is no one structure that works best for every operation. Any discussion to change silage structures (and thus, feed-out activity) should be discussed with your nutritionist and other members of your silage team.
Authors want to extend a special thanks to all participant dairies that took the time to complete the survey.
Reference: Heguy, J.M., D. Meyer, and N. Silva-del-Rio. 2015. A survey of silage management practices on California dairies. Journal of Dairy Science. doi: http://dx.doi.org/10.3168/jds.2015-10058.
Link to PDF Version: Silage Structure Options- Not One Size Fits All