Comparison of Portal and Jugular Blood Plasma Amino Acids in Lambs at Various Intervals Postprandial2

Abstract

Comparisons were made of the relationship between the level of plasma amino acids in portal and jugular blood of lambs fed a semipurified ration at various intervals after feeding. Although the total amino acid concentration fluctuated at the various postprandial sampling times, the changes in concentration of the plasma amino acids in jugular blood generally paralleled changes in portal blood, with the possible exceptions of methionine and lysine. A marked increase in the concentration of histidine and ammonia was noted in portal blood plasma; however, the increased concentration was not reflected in the jugular blood plasma. Urea levels were considerably higher in jugular plasma than portal plasma. In general, the highest concentration of most amino acids was found at 24 hr. postprandial.