EFFECTS OF INOCULANTS CONTAINING PROPIONIC-ACID BACTERIA ON FERMENTATION AND AEROBIC STABILITY OF CORN-SILAGE

The effects of microbial inoculants containing propionic acid bacteria on fermentation and aerobic stability of corn silage were examined. W hole-plant corn was ensiled for 3, 21, and 90 d in 5- to 7-kg capacity polyethylene bags, and six treatments were compared: no additive, Ped iococcus cerevisiae at 3 x 10(5) cfu/g of fresh forage plus Lactobacil lus plantarum at 1.5 x 10(4) cfu/g of fresh forage, Propionibacterium acidipropionici at 1 x 10(5) cfu/g of fresh forage, Pd. cereuisiae at 1 x 10(5) cfu/g of fresh forage plus Prop. acidipropionici at 1 x 10(5 ) cfu/g of fresh forage, Pd. cerevisiae at 1 x 10(5) cfu/g of fresh fo rage plus Prop. acidipropionici at 3 x 10(5) cfu/g of fresh forage, an d Prop. acidipropionici at 1 x 10(6) cfu/g of fresh forage. After each fermentation and storage period, silage was removed from each silo ba g and analyzed for dry matter content, pH, water-soluble carbohydrates , lactic acid, volatile fatty acids, ethanol, total N, and ammonia N. The addition of propionibacteria either alone or with Pd. cereuisiae h ad little effect on pH or concentrations of water-soluble carbohydrate s, lactic acid, and volatile fatty acids of the silages. Ethanol was n ot affected by treatment except at 90 d postfilling, when silage from forage treated with Pd. cerevisiae plus L. plantarum at the time of en siling had the highest concentration of ethanol. Aerobic stability of the silages was recorded upon opening the silo bags at 21 and 90 d pos tfilling. A 2 degrees C increase in temperature generally required a l onger time (about 2 h) for the silage from forage treated with Prop. a cidipropionici at 1 x 10(5) cfu/g of fresh forage and in silage from f orage treated with Pd. cerevisiae at 1 x 10(5) cfu/g of fresh forage p lus Prop. acidipropionici at 3 x 10(5) cfu/g of fresh forage.