Herbage, grain and animal production from winter-grazed cereal crops

Abstract

In four experiments from 1975 to 1979, wheat or oat crops were grazed to a standard height of about 6 cm (and to 2 cm as well in 1975 and 1976) at various times during winter by sheep, and by cattle also in 1979. Nitrogen was applied to a portion of each plot at the end of grazing. The crops were then allowed to recover for grain production. Herbage and grain yields, grain yield components, grazing days and liveweight gain were recorded. In two years, grazing significantly depressed grain yield relative to that of the ungrazed control, by 25-79% depending on treatment. In all years more herbage and animal production were obtained from a July or August grazing than from a June grazing. The greatest number of sheep grazing days recorded was 3414/ha for hoggets grazing oats for August 1977. lsis wheat was generally inferior to oats for grazing and grain production. Nitrogen increased grain and hay yields in three years; this increase was not profitable for grain, but was profitable for hay in at least one year. The most profitable use of winter cereal crops depends strongly on the relative prices of meat, grain, and hay. Our data suggest relationships between animal, hay, and grain production, which may be useful for farmers wishing to decide probable best options for using grazing-grain crops.