Effect of Whey Permeate and Lactobacillus buchneri on Biomass Conservation, Chemical Characteristics and Aerobic Stability of Elephant Grass Silage

Abstract

This study was carried out to evaluate the effect of whey permeate, bacterial inoculant and periods of fermentation and aerobic exposure on some characteristics of Pennisetum purpureum silage. The experimental design was completely randomized with three factors: whey permeate (0, 25, 50 and 100 g kg−1 of fresh matter—FM), bacterial inoculation with Lactobacillus buchneri (inoculated or non-inoculated), and periods of fermentation (from 1 to 35 days) or aerobic exposure (from 0 to 15 days). Cumulative losses increased sharply up to 14 days, but relative losses persisted up to 21 days in silage with 100 g kg FM−1 of permeate. The addition of permeate reduced neutral detergent fiber by between 16.2% (non-inoculated) and 17% (inoculated), and increased non-fibrous carbohydrates by between 66% (non-inoculated) and 79.3% (inoculated) during fermentation. Carbohydrate fractions followed opposing trends with air exposure, particularly up to 9 days of aerobiosis. Around 9 days of aerobiosis, the pH had the greatest increase (3.7 to 6.8), with NH3-N increasing after that time. L. buchneri increased aerobic stabilization, but higher levels of permeate increased temperature changes. Permeate must be used at 25 g kg−1 of fresh matter to increase the energy status of Elephant grass silage while providing substrate for fermentation and reducing fermentative losses. The best performance of this level of permeate should also be associated to L. buchneri for effective preservation of nutrients and to keep the aerobic stability of high-moisture Elephant grass silage, being indicated to improve silage conservation.