An investigation of lipogenic and glycolytic enzyme activity in the liver of sexually immature and mature domestic fowl.

In the non-laying pullet and the cockerel it was observed that there was no significant variation in the activities of ATP citrate lyase and ;malic' enzyme whereas in the laying hen there was a significantly greater activity of both these enzymes. Parallel increases in liver lipid content in the laying hen were also observed. Three glycolytic enzymes, phosphofructokinase, fructose diphosphate aldolase and pyruvate kinase, did not exhibit any significant variation in enzyme activity with the onset of egg laying. These results are discussed in relation to the hormonal status of the birds and also the demands of egg production for lipid.