Different organic acid preparations on fermentation and microbiological profile, chemical composition, and aerobic stability of whole-plant corn silage

Abstract

The objective of this study was to evaluate different preparations of organic acid (OA) products on whole-plant corn silage DM recovery, fermentation and microbiological profile, chemical composition, and aerobic stability. The following treatments were individually applied (4 g/kg as-fed) to silage contents (2 kg as-fed) of each mini-silo (n = 50, ten per treatment): control (CON; no OA addition); and different OA-based products at 4 g/kg as-fed: formic acid (FLE), sodium formate (SOL), propionic acid 1 (SPE), and propionic acid 2 (PER). Mini silos were opened after 120 d. Organic acid treatments increased DM recovery. When comparing formic acid (FLE and SOL) with propionic acid (PER and SPE) treatments, the latter exhibited greater DM recovery. Silages treated with OA exhibited lower temperature after oxygen exposure in comparison with CON. Organic acid treatments decreased buffering capacity, and lactic acid and acetic acid contents, while increasing the contents of propionic acid and ethanol. Propionic acid treatments increased silage contents of NH3-N, acetic acid, and propionic acid in relation to formic acid treatments. Organic acid treatments had marginal effects on microbiological profile of silages where silos treated with SOL had greater counts of lactic acid bacteria compared to those treated with FLE. Treating silages with OA reduced contents of aNDF and lignin, and increased contents of crude protein. Silages treated with formic acid-based products had lower contents of DM and non-fiber carbohydrates in comparison with those treated with propionic acid-based products. Regardless of product preparation, organic acids incorporation to whole-plant corn silage improved DM recovery and aerobic stability and decreased lactic acid content and proteolysis.