Effects of plant species, stage of maturity and additive on the feeding value of whole-crop cereal silage

This experiment aimed to study the effects of plant species, stage of maturity, additive and their interactions on yield, chemical composition and fermentation characteristics of whole-crop cereal silage. Barley, triticale, oats and spring wheat were harvested at the early milk stage or at the early dough stage of maturity in 2002 and 2003 with three field replicates of the plant species within each year. Proens (TM) (Perstorp Inc, Perstorp, Sweden), which contained 2/3 formic acid and 1/3 propionic acid, was applied at 4 L tonne(-1) herbage and Lactisil 2000 NB (Medipharm Inc, Kagerod, Sweden), which contained Lactobacillus plantarum, Enterococcus faecium, Pediococcus acidilactici, Lactococcus lactis, cellulase and sodium benzoate, was applied at 200 000 colony-forming units g(-1) herbage, and both applications were compared to untreated silage. Unwilted herbage, chopped at 12 mm. length, was ensiled in 4-L laboratory silos for 90 days. Barley had more starch whereas triticale had more sugar and crude protein but less neutral detergent fibre than other species (P < 0.001). Barley and triticale had less acid detergent fibre and lignin but greater in vitro organic matter (OM) digestibility than oats and spring wheat (P < 0.0001). Averaged over maturity stages, wheat had a greater yield of digestible OM than barley and oats (P < 0.0001). Yield of digestible OM and concentration of starch increased whereas sugar concentration decreased with later maturity stage (P < 0.0001). Late harvest increased the risks for high levels of butyric acid in silage when no additives were used (P = 0.002). Additives resulted in increased lactic:acetic acid ratios but decreased protein degradation and DM losses (P < 0.0001). Acid treatment was more effective than inoculation to degrade starch and to decrease protein degradation and DM losses during ensiling (P < 0.0001). Harvest at the early milk stage of maturity resulted in more lactic acid and a lower pH than harvest at the early dough stage of maturity (P < 0.0001). When considering both maximal yield of digestible organic matter and good silage quality, triticale, wheat or barley silage harvested at the early dough stage of maturity and ensiled with acid or inoculant is suggested. (c) 2007 Society of Chemical Industry.