The activity of aldolase, aspartate aminotransferase and the level of glucose in the blood plasma of chickens of various breeds and crossbreds.

Studies on the activity of aldolase, aspartate aminotransferase and on the level of glucose in the blood serum of chickens from various breeds and crossbreds have shown that: 1. Breed and sex had a significant influence on the level of glucose and the activity of aldolase and aspartate aminotransferase. 2. The highest level of glucose was observed in both sexes of White Rock chickens; the lowest in Greenleg hens and Leghorn cocks. 3. The highest activity of aldolase was observed in White Rock cocks and Plymouth Rock hens; the lowest in Greenleg hens and Leghorn cocks. 4. The highest activity of aspartate aminotransferase was observed in White Rock chickens; the lowest in Leghorns. 5. As regards the traits investigated, crossbreds, in comparison to the parental breeds, were characterised in a majority of cases by values intermediate or only slightly different. Cases of homosis and heterosis in the level of the physiological indicators examined were also observed.