Effect of exogenous prolactin on immunity in chickens.

The effect of exogenous prolactin on the number of peripheral white blood cells (WBC), anti-sheep red blood cell (anti-sheep RBC) and anti-rabbit red blood cell (anti-rabbit RBC) agglutinins was investigated in White Leghorn cockerels immunised twice with sheep RBC. It was found that prolactin, when administered for five days after second immunisation, raised production of anti-sheep RBC antibodies and lymphocyte number in comparison with the control group given injections of the solvent. Repeated injections of the solvent resulted in statistically significant differences in the number of granulocytes and lymphocytes.