The Digestibility and Voluntary Intake of S22 and H.1 Ryegrass, S170 Tall Fescue, S48 Timothy, S215 Meadow Fescue and Germinal Cocksfoot

Abstract

Pure swards of S22 Italian ryegrass, H.I hybrid ryegrass, SI70 tall fescue, S48 timothy, S2f5 meadow fescue and Germinal cocksfoot were each harvested at several stages of maturity during first growth in the spring, and in the subsequent regrowths. Each batch of herbage was fed to sheep in a digestion trial under conditions of voluntary intake. Results from the first growth herbages showed the expected fall in digestibility with increasing maturity. However, the digestibility of S22, H.I, S170 and S48 began to fall well before ear emergence, whereas the digestibility of Germinal fell only slowly up to the time of ear emergence, as had been found previously with S24 and S23 ryegrass and S37 cocksfoot. The rate of fall of digestibility in H.I and S48 (0-4 units/day) also appeared to be lower than with the perennial ryegrasses and cocksfoot (0-5 units/day). The monthly regrowths within each herbage were of similar digestibility, but the mean digestibility of regrowths differed between herbages, being highest for S215 and lowest for Germinal and S170. The grasses with highest digestibility in the early Spring, in particular S22 ryegrass, were not, however, always the most digestible in the subsequent regrowths. The numbers of sheep fed on each herbage were insufficient to show whether there were significant differences in voluntary intake between different herbage species of the same digestibility. It is suggested that an intake/digestibility relationship, based on data from more animals, should be developed for each herbage species. Only if different relationships are found can it be concluded that factors other than level of digestibility have an effect on intake.

Agronomic characteristics and nutritive value of 11 grasses grown with irrigation on a saline soil in southwestern Saskatchewan

“…than stems (Minson et al 1964;Laredo and Minson 1973;Hides et al 1983). However, lack of persistence under the conditions of this experiment would severely restrict the usefulness of meadow bromegrass for hay or grazing.…”

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

“…All other attempts to measure the intakes of these pasture species have been conducted indoors (e.g. Minson, Harris, Raymond, and Milford 1964;Joyce and Newth 1967;Rattray and Joyce 1969).…”

Growth factors and management technique used in relation to the developmental rhythm and yield formation pattern of a clover-grass stand

“…At the same stage of development the digestibility is usually better in an early type grass than in a late type (Pritchard et al 1963, Christie andMowat 1968). On the other hand, the digestibility of a late type plant species such as red clover remains good longer (Minson et al 1960, Raymond 1969). According to Hakkola (1978) English rye grass had the highest and orchard grass the lowest digestibility at all stages of development.…”