Blood parameters in draught oxen during work: Relationship to physical fitness

Abstract 1. 1. Four Zebu and four Simmental oxen were submitted to moderate and exhaustive work. Venous blood samples were taken before, immediately after and 30 min after work and assayed for several blood parameters. 2. 2. Draught work led to a decrease in carbon dioxide ( pν CO 2 ) and increases in pH, oxygen ( pv O 2 ), triglycerides, free fatty acids (FFA) and laetate. 3. 3. Zebu oxen had higher pν CO 2 and FFA and lower pH, pν O 2 and lactate in response to exercise. 4. 4. Ratios of individual draught power output and values of pv O 2 and lactate after work enable the identification of fit and/or weak individuals.