A mixed perennial ryegrass and white clover sward must be grazed to a short height to encourage clover growth. If high milk output is expected a supplement must be offered. A straw and concentrate mix (strawmix) utilizes surplus straw and enables nutrient intake to be controlled. Forage supplements also reduce the risk of bloat. In this experiment strawmix supplements of varying energy and protein content were compared.

Twenty Friesian dairy cows were allocated to a Latin Square design with five treatments: no supplement N, or pasture supplements of high or low energy (E and e) and high or low protein (P or p) in a factorial design (Table 1). Energy and protein contents were manipulated by changing the concentration of molasses and soyabean meal respectively.