Milksolids production from different combinations of perennial ryegrass and white clover cultivars: II Milksolids production and farm profitability

Abstract

1999/2000 and 2000/2001 were the first two complete seasons of a replicated farm systems trial designed to measure the effects on whole farm profitability (Economic Farm Surplus (EFS) of mixtures of ryegrasses and white clovers released on to the market recently, or at least 15 years ago, and rotationally grazed by dairy cows. All the pastures were sown in late autumn 1998. There were four treatments with all combinations of 1980s (80R), and late 1990s (98R) ryegrasses, and 1960s (60C)and late 1990s (98C) white clovers, each replicated 3.0 times in a randomised block design giving twelve 4-ha, self-contained farmlets stocked with three Friesian cows/ha. Milksolids production was unaffected by either ryegrass or clover cultivar age, but there was a significant ryegrass x clover cultivar interaction reflected as higher milksolids production on the 80R/98C treatment than the 98R/98C treatment in 1999/2000. This was a result of a higher clover content in the 80R/98C pastures compared with other treatments. Although the difference in clover content was still present in 2000/2001, the wetter summerÂ-autumn meant the ryegrass maintained a higher nutritive value than in the previous season under dry conditions, so clover content did not affect milksolids production in 2000/2001. There were no main treatment effects on EFS in either season, but there was a significant ryegrass x clover interaction in 1999/2000 shown as a higher EFS on the 80R/98C treatment than on the 98R/98C treatment. Keywords: cultivars, dairying, Economic Farm Surplus, milksolids, perennial ryegrass, white clover