Oil coating of dietary protein for the ruminant.

Diets containing expeller-extracted linseed meal treated with corn oil, lard or coconut oil were fed to lambs to determine the effectiveness of coating the protein in reducing its ruminal degradation. Three common indicators of nitrogen metabolism in the ruminant were used in evaluation: ruminal ammonia, blood plasma ammonia and plasma urea. Eight crossbred lambs, averaging 27 kg in weight, were allotted to the four diets which were fed at a rate of 350 g at 12-hour intervals. Ruminal ammonia, plasma ammonia and plasma urea were monitored at 0, 2, 4, 6 and 8 hr after feeding. Lambs consuming coconut oil-treated linseed meal produced less rumen ammonia (average of .5 mg/100 ml across all collection times) than those fed normal linseed meal (10.3 mg/100 ml). Lambs fed corn oil-treated and lard-treated linseed meal had ruminal ammonia levels intermediate to those fed normal and coconut oil-treated linseed meal. Levels of plasma ammonia and plasma urea nitrogen of normal linseed meal were significantly higher than the same measures with the oil-treated linseed meals. Differences in plasma ammonia and urea nitrogen were not significant among the three oil-treated diets.