[Comparative studies of blood sera and lactosera by agar gel precipitation (AGP) in enzootic leukemia in cows].

Studied were a total of 70 samples of blood and corresponding lactosera taken from lactating cows that were positive for leukosis on three farms with records for the disease. The lactosera were obtained from the milk samples through treatment in two ways--with calcium chloride and with chymosin. The experiments were carried out with untreated blood sera and with the lactosera obtained in both ways. Parallel to these, blood sera and lactosera were both studied in a concentrated state after being deeply frozen and centrifugated. The agar gel precipitation test (AGPT) was employed. It was concluded that the procedure described was a readily applicable method for laboratory use in the way of establishing enzootic leukosis, making unnecessary the blood sampling on a mass scale as undesirable from an economic and epizootic viewpoint.