AGRONOMIC AND CHEMICAL CHARACTERISTICS OF Kochia scoparia (L.) Schrad. AND ITS VALUE AS A SILAGE CROP FOR GROWING BEEF CATTLE

Abstract

Kochia (Kochia scoparia (L.) Schrad.) was grown on land irrigated with packinghouse wastewater and ensiled in a plastic silo bag. Kochia dry matter (DM) yield and acid-detergent fiber (ADF), Na, Mg, Mn, and Cu contents (DM basis) were correlated with some soil measurements. Alfalfa silage was replaced with kochia silage in a basal diet at levels of one-half (35% of diet DM) or all (70% of diet DM) of the roughage. The diets were fed to 120 calves (initial weight 294 kg) for 70 d in a completely randomized experiment with three treatments (kochia, kochia and alfalfa, and alfalfa) and four pen replicates. Inclusion of either 35 or 70% kochia silage in the diet DM depressed (P < 0.01) DM intake (DMI) by 23.3 and 50.1%, respectively, compared with calves fed the basal diet. Average daily gain (ADG) and final bodyweight of the calves fed kochia silage were both less (P < 0.01) than those fed the basal diet. DM conversion to liveweight gain ratios (DM: G) were 13.91, 8.42, and 7.15 when the diets contained (DM basis) 70, 35, or 0% kochia silage, respectively. Over the 42-d period following the trial, the calves that had received kochia silage tended (P = 0.078) to gain faster than those that had been fed the basal diet. The reduction in DMI observed when kochia silage was fed appeared to be the result of advanced maturity and weather damage of the kochia and not due to apparent toxic effects. Key words: Kochia, silage, beef cattle, soil salinity