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 chl oride) airtight containers for 21 days to determine the effect of grou nd sorghum and propionic acid-producing bacteria (PAPB) on the stabili ty of orange pulp silage. The treatments were as follows: orange pulp alone (control); orange pulp with ground sorghum grain; orange pulp wi th PAPB; and orange pulp plus sorghum grain and PAPB. The initial DM v alues of the control and sorghum grain-treated orange pulp silage were 22 and 33.5%, respectively. Total DM losses for the treatments with a nd without sorghum grain were 13 and 32%, respectively. After the silo s 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 sor ghum grain-treated silage increased to about 36-degrees-C, whereas the temperature of the treatments without sorghum grain increased to abou t 32-degrees-C. Ethanol was the major fermentation product. Treatments with sorghum grain had less glucose, less ethanol, and less propionat e but more lactate and crude protein than treatments without sorghum g rain. Treatments with PAPB had more glucose and propionate. The additi on of sorghum grain or PAPB did not improve aerobic stability as measu red by changes in temperature. However, sorghum grain plus PAPB altere d the fermentation pattern and may be useful additives to improve citr us pulp silage.