Studies on the causes of the differences in pasture quality between perennial ryegrass, short-rotation ryegrass, and white clover

Abstract

Abstract In two experiments the intakes and utilisation of pure swards of perennial ryegrass (P), short-rotation ryegrass (S), and white clover (C) were measured with grazing sheep, under conditions where there were differences in live-weight gain between treatments. There were differences in feed intake, but, because of high variability between animals, few were statistically significant. The intake of S was generally higher than that of P. In one experiment the intake of C appeared to be higher than that of the ryegrasses, but this was not repeated in the second experiment. There were consistent differences in the gross efficiencies of utilisation of digested energy for live-weight gain in both experiments, in the order C>S>P. Possible reasons for these differences in intake and utilisation are discussed.