Forty-four pairs of game-farm mallards (Anas platyrhynchos) were fed ABATE® 4E (temephos) to yield 0, 1, or 10 ppm ABATE® beginning before the initiation of lay, and terminating when ducklings were 21 days of age. The mean interval between eggs laid was greater for hens fed 10 ppm ABATE® than for controls. Clutch size, fertility, hatchability, nest attentiveness of incubating hens, and avoidance behavior of ducklings were not significantly affected by ABATE® ingestion. The percentage survival of ducklings to 21 days of age was significantly lower in both treated groups than in controls, but brain acetylcholinesterase (AChE) activity was not inhibited in young which died before termination of the study. In 21-day-old ducklings, aspartate aminotransferase (AST) activity increased and plasma nonspecific cholinesterase (ChE) activity was inhibited by about 20% in both treatment groups, but there were no significant differences in brain AChE or plasma alanine aminotransferase (ALT) activities, or plasma uric acid concentration. Clinical chemistry values of adults were not affected. No ABATE®, ABATE® sulfoxide, or ABATE® sulfone residues were found in eggs or tissue samples.
