Herbage mass, nutritive value and palatability of five grass weeds for cattle in the northern Tohoku region in Japan

The objective of this grazing study was to determine the herbage mass, nutritive value and palatability of five grass weed species ( Eleusine indica (L.) Gaertn, Paspalum thunbergii Kunth, Digitaria ciliaris (Retz.) Koeler, Setaria glauca (L.) Beauv. and Echinochloa crus-galli (L.) Beauv. var. crus-galli ) as feeds compared with six forage cultivars ( Lolium perenne L., two Lolium multiflorum cultivars and three Echinochloa crus-galli (L.) Beauv. cultivars). The herbage mass of weed species, with the exception of S. glauca , was most prevalent in August. The total amounts of herbage mass of weed species (except E. indica ) were close to those of the Lolium cultivars, but lower than those of the E. crus-galli cultivars. During the summer, weed species (except E. crus-galli var. crus-galli ) contained favorable levels of total digestible nutrients (TDN), crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF) and mineral contents, and exhibited adequate calcium (Ca):phosphorus (P) ratios of 1:2. All weed species had the recommended ratios of potassium (K):(Ca + magnesium] Mg) < 2.2:1. By autumn, the summertime levels of nutritive values (TDN, CP, ADF and NDF) in the weed species had severely deteriorated, in contrast with those of the forage cultivars. However, they maintained satisfactory mineral content levels and Ca:P and K:(Ca + Mg) ratios (with the exception of E. indica with poor Ca:P ratios and E. crus-galli var. crus-galli with poor P content and Ca:P ratios). All weed species were acceptable to cattle, although there were some differences in palatability among the species.