Evaluation of medics under continuous grazing with sheep in central-western New South Wales

Abstract

Between May 1974 and March 1978, dry Merino ewes continuously grazed l-ha plots, sown to Medicago truncatula cvv. Akbar, Borung, Cyfield, Cyprus, Hannaford and Jemalong, and M. tornata cv. Tornafield, at a stocking rate of 4 Ewes/ha. Hannaford and Cyfield grew most vigorously; Borung least. Pod accumulation declined during the experiment, but plant counts showed a satisfactory density of all medics at the end of the experiment. Sheep on cultivars Hannaford, Cyprus, Cyfield and Tornafield required no hand-feeding during the experiment; those grazing the other cultivars required hand-feeding in autumn-winter 1975. There were no significant differences between treatments in fleece-free liveweights or annual clean fleece yields. In 1977 the medic content of the diet was less than 50% in all treatments. Pod ingestion over summer increased steadily to nearly 70% of the diet as the more palatable pasture components became scarce. However, the proportion dropped rapidly when summer rain provided sheep with a green 'pick'. The spiny pods of Akbar were retained in the fleece; the spineless pods of other cultivars were never retained. Total vegetable matter contamination was less for Cyfield than for Akbar, suggesting that development of medics with less spiny pods is a justifiable objective.