Effects of laboratory ensiling method, microbial inoculation, and storage length on the fermentation profile and nutrient composition of whole-plant corn silage and high-moisture corn

Abstract

The objectives of this experiment were to compare the effects of laboratory ensiling methods (plastic buckets or vacuum-sealed plastic bags) and microbial inoculation (Lentilactobacillus buchneri AHLB02 and Pediococcus pentosaceus AHPP02; LBPP or the same amount of distilled water; CON) on the fermentation profile and nutrient composition of WPCS and HMC. Moreover, this study aimed to evaluate the effects of microbial inoculation on aerobic stability of WPCS and HMC ensiled in buckets. Whole-plant corn was packed into 20 L plastic buckets to a density of 195 kg of DM/m3 or 900 g of sample material placed in nylon-polyethylene standard barrier vacuum pouches and inoculated with 300,000 CFU of LBPP/g of fresh forage or CON. High-moisture corn was packed into 3.785 L plastic buckets to a density of 792.5 kg of DM/m3 or 1300 g of sample material placed in nylon-polyethylene standard barrier vacuum pouches and inoculated with 450,000 CFU of LBPP/g of fresh material or CON. Silos were randomly assigned to 30 or 90 d of storage. Data were analyzed as a completely randomized block design with field location as a blocking factor in a 2 × 2 × 2 factorial arrangement of treatments using PROC GLIMMIX of SAS with fixed effects of ensiling method, microbial inoculation, storage length, and all their interactions with significance at P ≤ 0.05. Whole-plant corn silage had greatest (P = 0.001) pH for LBPP silage ensiled in bucket, intermediate for LBPP silage fermented in bag, and lowest for CON silage ensiled in bucket. The 1,2-PD concentration was greatest (P = 0.001) for LBPP silage fermented in bag, intermediate for LBPP silage fermented in bucket, and lowest for CON silage. High-moisture corn had greater (P = 0.04) lactic acid concentration for silage ensiled in bucket for 30 d than 90 d. Acetic acid concentration was greater (P = 0.01) for inoculated HMC ensiled in bucket compared with other treatments at 90 d. Moreover, lactic acid concentration was lower (P = 0.001) for LBPP than CON in both silages. Total acids concentration was greater (P = 0.001) for 90 d than 30 d in both silages. High-moisture corn had greater (P = 0.01) acetic acid concentration for LBPP than CON at 30 d. The 1,2-PD concentration was greatest (P = 0.001) for LBPP at 90 d, intermediate for LBPP at 30 d, and lowest for CON. Both ensiling methods are comparable and suitable for laboratory silage research. Microbial inoculation improved fermentation of both WPCS and HMC but this response was more pronounced at 90 d.