The Consumption of Perennial Ryegrass and Red Clover by Grazing Lambs

Abstract

Groups of six-month old lambs, which were either experienced or inexperienced grazers, stripgrazed swards of S24 perennial ryegrass or Hungaropoly tetraploid red clover, at daily herbage allowances of 20 or 40 g OM/kg LW, in late August and September. The swards were similar in N content, but the weight of standing crop, and its digestibility, were higher on grass than on clover. Estimates of herbage intake were made in two successive periods of 19 days. Intake (g OMAg LW) was lower at low than at high allowance (by 22% and 28% in periods I and II). and experienced grazers ate more than inexperienced animals (by 27% and 22%). Intakes on clover were 28% higher than on grass in Period I, but in Period II the difference was not significant.

Effects of season, stocking rate, and grazing duration on diet selected by hoggets grazing mixed grass-clover pastures

“…Diet selection was for green leaf, a result consistent with other reports (Arnold 1964;Hamilton et al 1973;Hodgson 1975;Langlands 1975). When the percentage of dead material on offer in the pasture increased, the dietary intake of green leaf decreased, and the intake of dead matter increased.…”

“…11, Foxton, New Zealand Received 30 June 1980; revision 18 March 1981 The total amount of herbage on offer is rarely the amount apparently available to the grazing animal, since the diet is selected almost exclusively from the green components (Arnold 1964;Hamilton et aI. 1973;Hodgson 1975;Mulholland et aI. 1977).…”

A quantitative model of energy intake and partition in grazing sheep in various physiological states

“…It was therefore anticipated that food intake would be significantly overestimated if this type of experiment was simulated. This was indeed the case when the observations on forage intake by lambs grazing Lolium perenne, reported by Hodgson (1975), were simulated. The levels of intake predicted were about twice those observed in two consecutive periods during which both the availability and digestibility of the pasture changed, although the direction of the changes was correctly predicted.…”

“…Hodgson, 1975;Gibb and Treacher, 1976). The high stocking rates used in these trials and the daily changes in forage availability that occur in stripgrazing are likely to be major factors in influencing competition between animals for the available pasture and limited space generally allotted.…”

“…Simulations of the experiments of Hodgson (1975) and Arnold (1975) were used to study the sensitivity of the model to data input not readily available, i.e. GRSAGE.…”