UNASSIGNED: Changes in the quality of eggs of birds exposed to @entity3215 ( @entity3215 ) have been described, but have never been directly attributed to @entity3215 . Polychlorinated @entity30708 residues in eggs have been associated with reduced reproductive success and @entity85 in wild birds. Egg size and composition, specifically the amount of albumen, yolk, and water in an egg, also influence the growth and viability of embryos and hatchlings, and consequently the reproductive success of birds. To deter mine whether @entity5241 exposure of adult birds affected the size and composition of their eggs, 25 pairs of captive @entity41376 ( @entity41376 ) were fed a mixture of @entity5241 -spiked (1248:1254:1260) food to give an approximate exposure of 7 mg/kg body weight/d, beginning 1 mo prior to pairing, and continuing throughout the courtship, egg-laying, and incubation periods. This dietary level in the adult female kestrels resulted in mean total @entity5241 residues in the eggs of 34.1   g/g wet weight (geometric mean), which is environmentally relevant. @entity5241 residues in eggs increased with the time of female exposure to the contaminated diet and laying date. Variation in egg size within @entity5241 clutches was significantly greater than within control clutches, although absolute egg mass and volume did not differ markedly by treatment. Only infertile eggs and only one egg per clutch were used for egg composition analysis. Yolks in the @entity5241 -contaminated eggs were heavier, with less wet and dry albumen relative to control eggs. Water content and eggshell thickness were not significantly affected by @entity5241 exposure. These results suggest that eggs from the @entity5241 treatment have relatively more lipid and less protein available for embryonic development. Changes in egg composition were not associated with egg size, lay date, ambient temperature, humidity, or precipitation, which are factors known to affect these variables in bird eggs. The @entity5241 -induced changes in egg composition described here provide insight into possible mechanisms contributing to reduced reproductive performance in wild birds exposed to @entity3215 .

CHANGES IN EGG COMPOSITION OF XXXX EXPOSED TO DIETARY @entity3215 .

@entity5241 :: ('CHEBI:47136', 'Chemical') :: ['PCB'] @entity41376 :: ('56350', 'Species') :: ['Falco sparverius', 'American kestrels'] @entity3215 :: ('MESH:D011078', 'Chemical') :: ['polychlorinated biphenyls', 'PCBs'] @entity85 :: ('MESH:D009140', 'Disease') :: ['embryonic deformities'] @entity30708 :: ('MESH:C010574', 'Chemical') :: ['biphenyl']
@entity41376 :: (56350,Species) :: ['AMERICAN KESTRELS']
