STUDIES ON THE FEEDING VALUE OF Kochia scoparia (L.) Schrad. HAY FOR BEEF CATTLE
Intake, digestibility, nitrogen retention and the effects of 2.6% soluble oxalates in the dry matter (DM) of kochia (Kochia scoparia (L.) Schrad.) were examined when beef steers were fed rations varying from 100 to 0% kochia hay and 100 - 0% bromegrass (Bromus inermis Lyess.)/alfalfa (Medicago sativa L.) hay. Plasma Ca, P, Mg, Zn, Fe and Cu concentrations were normal and not affected by supplementation with CaCO3. The organic matter digestibility (OMD) of kochia (55.4%) was less (P < 0.05) than that of the bromegrass/alfalfa hay (61.3%). However, in a second trial, OMD was not influenced if kochia was included at up to 60% of the ration. In a third trial, DM intake remained constant until 60% kochia was present in the ration but was reduced (P < 0.01), even with careful adaptation, when kochia exceeded 60% of the diet. Nitrogen retention declined (P < 0.05) as the proportion of kochia in the ration increased and was negligible at 100% kochia. Key words: Kochia, digestibility, intake, nitrogen retention, plasma minerals, cattle (beef)