EFFECT OF SORGHUM GRAIN AND PROPIONIC-ACID BACTERIA ON FERMENTATION PATTERN, DRY-MATTER LOSS, AND AEROBIC STABILITY OF ORANGE PULP SILAGE

Orange pulp at 22% dry matter (DM) was ensiled in 2.7-L poly(vinyl chloride) airtight containers for 21 days to determine the effect of ground sorghum and propionic acid-producing bacteria (PAPB) on the stability of orange pulp silage. The treatments were as follows: orange pulp alone (control); orange pulp with ground sorghum grain; orange pulp with PAPB; and orange pulp plus sorghum grain and PAPB. The initial DM values of the control and sorghum grain-treated orange pulp silage were 22 and 33.5%, respectively. Total DM losses for the treatments with and without sorghum grain were 13 and 32%, respectively. After the silos were opened, the temperature in all silages increased from 22 to 31-degrees-C over 3 days. From day 3 to day 8, the temperature of the sorghum grain-treated silage increased to about 36-degrees-C, whereas the temperature of the treatments without sorghum grain increased to about 32-degrees-C. Ethanol was the major fermentation product. Treatments with sorghum grain had less glucose, less ethanol, and less propionate but more lactate and crude protein than treatments without sorghum grain. Treatments with PAPB had more glucose and propionate. The addition of sorghum grain or PAPB did not improve aerobic stability as measured by changes in temperature. However, sorghum grain plus PAPB altered the fermentation pattern and may be useful additives to improve citrus pulp silage.