Relationship of serum alpha-amylase to aflatoxin resistance in Japanese quail.

Serum alpha-amylase (S alpha A) activities were examined in a non-selected population (NS) of Japanese quail and in two lines genetically selected for resistance to aflatoxin. Normal S alpha A activities of both selected lines were significantly lower than that of the NS line (P less than or equal to 0.05). An oral dose of 2.5 mg aflatoxin/kg body weight significantly lowered S alpha A activity in NS quails after 24 hours; 18.0 mg/kg body weight was required to decrease the activity in selected lines to a similar degree. The two selected lines did not differ significantly in response. Disc tube gel electrophoresis of the serum revealed eight bands of S alpha A activity and six S alpha A zymogram phenotypes in the total population using an iodine-staining technique. Neither migration distance nor band width varied with genetic line, but the frequency of quails with at least one of three specific anodic bands was significantly higher in the selected lines (75% and 100%) than in the NS line (27%). The frequencies of the zymogram phenotypes with these bands were similarly increased in the resistant populations. Although there are differences in total S alpha A activity between the selected aflatoxin-resistant lines and the NS line, the presence of specific electrophoretic anodic band types and the S alpha A zymogram may be more useful indicators of aflatoxin resistance.