BREWERS GRAINS AS A SOURCE OF SELENIUM IN BEEF CATTLE RATIONS

Soils, and therefore crops, deficient in selenium in the Northeastern United States are well-known. Brewers grains containing barley grown on high-selenium western soils should serve as an efficient supplementary source of the element in cattle rations. In this study, beef cattle were fed a diet containing brewers grains for six months and their concentration of selenium in blood was compared to a control group of cattle fed a comparable diet but without brewers grains. The concentration of selenium in the blood of the cattle receiving brewers grains increased significantly (p < 0.01) from an initial level of 12.15 ± 2.74 (average ± standard deviation) micrograms/100 mL to 22.88 ± 3.54 at the end of the feeding period. The control group showed a nonsignificant increase from 15.35 ± 2.29 to 16.19 ± 2.08. There was no significant (p > 0.05) increase in average rate of weight gain between the two treatment groups.     

EXTRACTION of MILK FAT IN HIGH PRESSURE SOLVENTS

Extraction of milk fat in several high pressure solvents was compared. Solubility of milk fat in supercritical (SC) ethylene and liquid propane was compared to previous results in SC CO₂. At the same operating conditions (temperature and pressure), solubility of milk fat was higher in SC ethylene than in CO₂, although levels generally remained below 5% (w/w). This resulted in significantly higher solubility in SC ethylene when compared at equivalent solvent density. Very little fractionation of milk fat occurred in liquid propane over the range of pressures (3.45 to 5.52 MPa) and temperatures (30 to 90C) studied. Below 77.5C and 2.76 MPa, liquid propane and milk fat were miscible, while a slight fractionation was observed above these conditions. A high pressure sight-gage apparatus was used to visually confirm these conditions for separation.