Comparison of avidin and biotin levels in eggs from turkey hens with high and low hatchability records.

Levels of biotin and avidin were assayed in eggs from Small White turkey hens having 12-15 week average hatchability of fertile egg records (HF) of 13 and 99%. The median level and concentration of avidin was higher in eggs of the 13% HF (2.72 mg and 42.5 micrograms/ml, respectively) as compared with the 99% HF (1.39 mg and 23.8 micrograms/ml, respectively). Calculations for total biotin to avidin binding in the eggs revealed that all eggs in the 13% HF and residual free avidin levels after total biotin was complexed to avidin. This complex formation is expected to have limited the availability of biotin for embryonic development.