Growth, nutritive value and selection by sheep of sainfoin, red clover, lucerne and hybrid ryegrass

Abstract

SUMMARYA site containing plots of sainfoin, red clover, lucerne and hybrid ryegrass, each sown as a pure stand, was grazed by sheep three times in the first and second harvest years and once in the third. Crop growth was studied during the 8 weeks preceding each grazing.Sainfoin had a high proportion of green leaf and a high weight per unit area of leaf, and the stem as well as the leaf was readily eaten. The yield and persistence of sainfoin were poor, the number of plants and the number of shoots per plant were low, the development of leaf area was slow, and nitrogen content and digestibility were rather low.Red clover had a high proportion of green leaf, large leaves, high nitrogen content and fairly high digestibility, and the stem as well as the leaf was readily eaten. Yield was low except at the first two grazings of the first harvest year, and persistence was poor, there being a large number of plant deaths near the time of the second grazing.Lucerne was higher yielding and more persistent than the other legumes, with a satisfactory number of plants, a relatively large number of shoots per plant, a high rate of emergence of leaves and a relatively large amount of branching. The lucerne had a rather high proportion of stem, and the stem was of rather low digestibility and not very attractive to the sheep.The hybrid ryegrass yielded more herbage than the legumes, had a satisfactory and increasing number of tillers, increased in yield relatively early in spring and recovered well after defoliation. The proportion of green leaf was low by the end of each of the first two growth periods of each year, the leaves emerged at a rather slow rate in the later stages of a growth period, the crop had a relatively high proportion of cell wall and the stem in particular was relatively unattractive to the sheep.