Use of forage inoculants with or without enzymes to improve preservation and quality of whole crop barley forage ensiled as large bales

Abstract

The effects of forage additives, applied to bales wrapped at either 2 or 10 h post-baling, on preservation and quality of whole barley crop ensiled as large bales were investigated. Forage was cut at the early milk stage and allowed to wilt over a 24-h period to 47% DM. Bales were allocated on the basis of baling sequence to one of three additives treatments: without inoculant (Control); treated with a microbial inoculant, Lactobacillus plantarum and Pediococcus cerevisiae (LpPc); or treated with Lactobacillus plantarum and Pediococcus cerevisiae, plus cellulase and pectinase (LpPcE). An equal number of bales (n = 18) representing each treatment group were wrapped at either 2 or 10 h post-baling. All bales were core sampled at baling and on days 1, 2, 3, 6, 9, 13, 17, 29, 64, 92, 252 and 308 post-baling. Bales were weighed prior to being wrapped and when removed from storage to measure DM and nutrient losses during storage. During wrapping, a thermocouple wire was inserted in each bale to monitor bale temperature. Time of wrapping did not affect nutrient composition or ensiling characteristics of silage. Application of forage additives had no effect on nutrient profile or recovery, however, silage treated with LpPc inoculant had lower (P < 0.05) ammonia N compared with untreated or treated with LpPcE silage. Storage temperature of bales representing all treatments did not exceed 28 °C but were approximately 2 to 3 °C higher in the Control than treated silage for the first 3 d post-ensiling. Silage treated with forage additives had a lower (P < 0.05) pH and an increase (P < 0.05) in concentrations of lactic and total acids. Ethanol and 2,3 butanediol levels were higher (P < 0.05) in untreated silage compared with inoculated silage. Silage treated with forage additives were more stable and took 5, 9 and 12 d to heat after exposure to air for Control, LpPc and LpPcE silage, respectively. Results from this study indicated that treatment with microbial inoculants was beneficial in preserving whole crop barley ensiled as large bales. Addition of enzymes to microbial inoculant did not have further beneficial effect on quality of large bale silage. Key words: Silage, large bale, whole crop barley, forage additives, ensiling characteristics