The effect of an acid salt‐type additive on the fermentation of grass silages made in bunker silos on commercial dairy farms in Wales

Abstract

AbstractThe fermentation characteristics and chemical composition of 57 first‐cut and 30 second‐cut samples of grass silages, made in bunker silos on commercial dairy farms in Wales in 1990, and treated with a nominal 61 t−1 of an acid salt‐type additive at ensilage, is described. Typical chemical composition of grass cut for ensilage was 156 g kg−1 dry matter (DM) and 28 g kg−1 water soluble carbohydrate (WSC), with 181 g (kg DM) −1 crude protein (CP) and 232 g (kg DM) −1 modified acid detergent fibre (MADF). The effect of additive use was to produce silages with DM 230 g kg−1 pH 3·93, ammonia N 70 g kg−1 total N, with residual WSC 35 g (kg DM) −1, lactic acid 83 g (kg DM) −1, total acids 118 g (kg DM) −1 and butyric acid 0·7 g (kg DM) −1. No significant differences were found between first‐ and second‐cut silages. Silage fermentation was restricted (i.e. lactic acid less than 60 g kg DM−1) in only 20% of the samples.It is suggested that on commercial farms the application rate achieved may be insufficient to produce a restricted fermentation.