POTENTIAL FOR PELLETIZED SOYBEANS AS FORAGE FOR DAIRY COWS IN SAN CARLOS, COSTA RICA

Abstract

Dairy producers in Costa Rica primarily utilize grazing systems for their production systems; however, they must supplement with high amounts of imported grain because pasture quality is low and can negatively impact milk yields or weight gain. In this research study, we used the industrial process to make forage pellets out of whole plant soybean (Glycine max. L. Mer var CIGRAS 06) at the R6 stage in order to provide a high quality feed that is potentially more affordable than imported feeds. During this process, the soybean was dehydrated to 24.01% moisture content (MC) to create pellets. The pellets were evaluated for their nutritional value. These samples were taken in all phases of the process including a sample of the whole plant soybean. The soybeans were planted at a density of 773,514 seeds per acre. The yield obtained was of 6.04 DM tons/acre. This low yield occurred because of the low photoperiod and high rainfall during the time frame of September, October and November. The dehydrator was built from recycled materials. The capacity of the dehydrator was of 3.49 lbs per hour of dry forage and with an evaporation of 9.88 lbs H₂O/hr. The energy required for the process was 0.278 lbs (LPG)/lb of dry forage. Pellet process was performed with a pelletizer property of Tico Fruit. The total production obtained was 0.414 tons of soybean pellets, with a 75.99% DM and a relative feed value (RVF) of level 3. The average for crude protein (CP) was 16.66%, acid detergent fiber (ADF) was 40.20%, neutral detergent fiber (NDF) was 55.11%, and fat was 3.35%. The pellets had a final size particle of 0.256 in of diameter and 1 in average of length. Production costs for the soybean pellet were 0.38 dollars per pound. The high costs were due to the dehydration of the forage because of the high content of water when the soybean was harvested in field at 81.48 % MC (Figure 2). Overall, this primary investigation leads us to a better understanding of what steps are necessary to creating a pelletized feed that could be adapted for feeding in Costa Rica.