Operational research study of forage conservation systems for cool, humid upland climates. Part 2: Comparison of hay and silage systems

Abstract

The improved operational research model described in Part 1 of this paper is exploited to compare the economics of hay and silage systems for climatically different areas of Scotland. Both field-dried and barn-dried hay are explored, and the silage systems studied include unwilted-clamp silage, wilted-clamp silage and baled silage. Also, high cost, high capacity systems are compared with low cost, low capacity systems for each method. Each system is costed and compared in terms of net value of forage produced. Results of simulation and feed evaluation runs for a range of grassland areas suggest that the economics of silage as a conservation method are nearly always more favourable than hay under Scottish climatic conditions. The economics of wilted silage are much better than unwilted silage. Silage systems should be based on a precision chop forage harvester for small farms, and on big bales rather than a flail forage harvester for small farms. Only on small farms in drier East of Scotland areas are the economics of haymaking comparable to silage, and here there is little to choose between field drying and barn drying. The importance of selecting a system with sufficient capacity for the quantity of crop to be conserved is also demonstrated. Parts of the model which could be further developed are discussed. Opportunities for further exploitation of the model in its present form have also been identified.