Abstract:
COMPARISON OF THREE CONTRASTING GRASS/CLOVER PASTURES FOR MILK PRODUCTION AND PROFITABILITY. G.N. O'BRIEN* The nutritional superiority for milk production of white clover over perennial ryegrass has been verified over the past . six years in thirteen experiments at the Ellinbank Dairy Research Institute. A milk yield response of approximately 20% occurs when cows are fed ad libitum while a response of approximately 10% occurs when cows are fed equal rations of grass or clover at 65% of ad libitum intake. Following three years monitoring of herbage production from pastures ranging in clover proportion from 15 to 100% white clover, it appeared possible to increase per cow and per hectare milk production by 10% as a result of increasing the proportion of clover in the pasture from 20% to 50% using Fusilade (R) herbicide (fluazifop-butyl). Another alternative for improving milk production using clovers is to introduce red clover (c.v. Redquin) into a pasture based milking system to more closely match feed supply with cow requirements. In this experiment, milk production and profitability from a farmlet with a traditional pasture system is compared with two high legume pasture systems. One system (high white) consists of white clover-ryegrass pastures with clover proportions between 50 and 60%. The other system (high red) comprises pure red clover pastures on half the farmlet and traditional pastures on the remainder. Each farmlet is 7 ha in area and stocked at two cows per hectare. TABLE 1 Production (per cow) from August calved cows on three farmlet systems from 29.9.87 to 11.5.88. Milkfat production was increased by 10% (Table 1) as a consequence of increasing the white clover content from 29% to 54%. Over the full lactation this is valued at $180 per hectare. At a cost of $50 per hectare for the Fusilade the increase is potentially profitable. As the red clover pasture was in its establishment year, milk production was below potential. * Dairy Research Institute, Ellinbank, Victoria, 3820. 19A