Fermentation characteristics and aerobic stability of grain sorghum (Sorghum bicolor) ensiled in Puerto Rico with various doses of commercial inoculum

Abstract

An experiment was conducted to evaluate the effectiveness of a commercial lactic acid-producing bacteria! inoculant (LAPBI) applied at 0, 1, and 2 times the recommended rate to improve the fermentation characteristics and aerobic stability of grain sorghum (Sorghum bicolor var Jupiter) ensiled in a tropical environment.The sorghum was harvested at 90 d of growth and chopped into 2.5-cm pieces. At ensiling, three treatments were imposed: no additive (control), and LAPBI applied at the recommended (5.477 cfu/g of fresh forage) or higher rate (5.788 cfu/g of fresh forage). Three silos per treatment were opened after 0, 2, 4, 7, 14, 28, and 56 d of fermentation, and silage was analyzed for pH, chemical composition and fermentation end-products. Addition of the LAPBI did not markedly influence the chemical composition of the silages at either rate. It did increase the acidity and acetic acid content during early stages of fermentation, and the lactic acid content at 56 d post-ensiling, but did not reduce the deterioration of silage after exposure to air. It is concluded that use of the LAPBI, applied at the recommended rate, partially improved the fermentation characteristics of the grain sorghum silage, but did not enhance its aerobic stability. Doubling the application did not produce beneficial effects.