Yield, nutritive value and silage fermentation of kura clover-reed canarygrass and lucerne herbages in northern USA

摘要

Excellent winter hardiness, persistence and nutritive value of both kura clover (Trifolium ambiguum M. Bieb.) and reed canarygrass (Phalaris arundinacea L.) suggest that intercropping these species could substitute for lucerne (Medicago sativa L.). The dry matter (DM) yield and nutritive value of herbage, and silage characteristics of kura clover-reed canarygrass (KC-RCG) herbage, were compared to those of lucerne over two growth cycles near Arlington, WI, USA. First and second growths of lucerne and KC-RCG herbage were sampled four times at 1-week intervals and ensiled for 100 d. Yield of DM of the KC-RCG was 0p"23-0p"57 greater than that of lucerne on sampling dates in the first growth cycle, with no differences in DM yield in the second growth cycle. The pH of lucerne silage was lower than that of KC-RCG silage in the first growth, and the opposite occurred in second growth, which was attributed to maturity differences and the proportion of kura clover in the mixture. Lactate concentration was lower in KC-RCG than lucerne silages in both growth cycles. The lucerne and KC-RCG silages had similar in vitro DM digestibility except for the final sampling date in the first growth cycle when neutral-detergent fibre concentration of KC-RCG herbage exceeded 550 g kgp# DM. Crude protein concentration was greater in lucerne silage than in KC-RCG silage in both growth cycles. Overall, differences in nutritive value and silage fermentation between the two herbages were minimal across growth cycles. These results suggest that a KC-RCG sward is a viable alternative to lucerne in northern environments of the USA where lucerne production may be limited by winter injury or edaphic factors.