Effects of inoculants and wilting on silage fermentation and nutritive characteristics of red clover–grass mixtures

Abstract

AbstractVarious management practices (e.g. wilting, application of silage additives or adding a grass component) can be used to improve silage fermentation of pure red clover (Trifolium pratense L.). Therefore, the aim of this laboratory ensiling study was to investigate the effects of varying proportions of red clover and perennial ryegrass (100/0, 66/33, 33/66, 0/100) on silage quality during two consecutive years. In addition, two wilting levels [target dry matter (DM): 300 vs. 400 g kg−1] in combination with lactic acid bacteria (LAB) additives were tested. Herbage was ensiled, either untreated or inoculated with homofermentative LAB (low wilted) or homo‐ and heterofermentative LAB (high wilted). In most cases, lactic and acetic acid decreased as the proportions of ryegrass were increased. Data concerning ammonia‐N concentrations showed considerable differences between cuts and years. Silages treated with homofermentative LAB generally had high lactic acid and low final pH, whereas acetic acid and 1,2‐propanediol tended to be higher when homo‐ and heterofermentative LAB were applied. Inoculants had a positive effect on DM losses and ammonia‐N in only a few silages. Wilting decreased DM losses and fermentation acids at most cuts, irrespective of the grass/clover ratio in the herbage mixture. There was a strong year effect on the organic matter digestibility (DOM) of the silages. In conclusion, the optimal strategy for successful silage fermentation of red clover is the ensiling in mixtures with ryegrass. Furthermore, herbage should be wilted to a DM content of about 300–350 g kg−1. The application of LAB inoculants did not alter the DOM but did improve silage fermentation.