Richard Stowell, Ph..D.
Department of Food, Agricultural, and Biological Engineering
A progressive dairy producer must consider ways of handling and managing manure that will prove reliable, efficient and economical into the coming years. Unfortunately, there is no single system of choice that will satisfy the needs of the variety of operations in place today or being planned. Experience and research have improved our ability to evaluate systems and make recommendations, however, and I will summarize a few of those key points.
The choice of bedding material is critical to the implementation of a good manure handling system. Changing a system of facilities to handle manure that is laden with a bedding material that was not accounted for in the systems design is very frustrating and potentially costly, if not unworkable.
The design of stall bed used in freestalls largely determines the bedding material that is selected. Two stall-bed designs have risen to the top as the choices of managers seeking cow comfort: the deep bed of sand and the baffled mattress with a covering of loose bedding, usually wood shavings or some other organic material. On the basis of cow comfort and performance alone, sand-based stalls have advantages over their mattress-based counterparts when given similar management attention. Producers need to evaluate (obtain an evaluation of) the expected costs/benefits of each of these designs to cow performance on their own operation.
Also, consider the available and preferred means of applying manure onto cropland. If all or most of the manure must be pumped a long distance, irrigated or injected, sand must be separated from the manure stream or mattresses should be used instead of sand-based stalls. On the other hand, if all or most of the manure is to be handled using a front-end loader and spread using a box or V-spreader, there is little or no advantage of handling loose manure from mattress-based stalls. In most cases, the available options for handling manure lie somewhere between these extremes, meaning either stall-bed design and bedding material could be used and comparisons should be made on an individual, system basis that includes producer preferences.
Given the bedding material, a handling system can be put together that suitably matches manure characteristics with prioritized facility and management needs. Sand-laden manure should be handled in one of the following ways:
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Undiluted, within a covered, concrete storage,
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In two or three steps (skim-and-haul) as liquid and solid, or as liquid, semi-solid and solid materials, using a storage with a concrete bottom and ramp, or
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As a well-diluted liquid with the sand removed and handled separately.
Manure from freestall barns having mattress-based stalls can be handled in several ways. Opportunities exist to utilize gravity-flow transfer systems, centrifugal pumps, and slatted floors. The primary considerations revolve much less around the manure itself and more around labor requirements, local topography, and specific manure management constraints.