Effects of Age, Body Weight, Stage of Gestation, and Sex on Plasma Glutamic-Oxaloacetic and Glutamic-Pyruvic Transaminase Activities in Immature Holstein Cattle

Abstract Glutamic-oxaloacetic and glutamic-pyruvic transaminases were measured in the peripheral plasma of 367 Holsteins in three herds, including open and bred heifers and young bulls. All animals were sampled within a three-week period when the daily mean temperature varied only 13 degrees Fahrenheit, making possible a within-season analysis. Since there was a highly significant difference (P Age affected both enzymes in young bulls (P Growth rate, age of puberty, and physiological as well as chronological age, and other components of management and environment cause differences in plasma of both transaminases.