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Muscle structure and blood enzyme activity were studied to 16 wk of age in lines of turkeys selected for rapid growth. The body and carcass weights were measured, frozen sections of breast and leg muscles examined, and plasma creatine kinase (CK) levels determined. Muscle weights were usually proportional to BW except for the relatively larger superficial pectoralis (SP) muscles in the most rapidly growing line. Damaged muscle fibers were found in all muscles examined, especially in the SP of the breast, the gastrocnemius (GA), and other muscles of the leg; these damages became more common from 10 to 16 wk of age. There were more degenerating muscle fibers and higher levels of plasma CK in the rapidly growing lines than in a slower growing unselected line. The findings support the idea that a focal myopathy, unrelated to deep pectoral myopathy or to inherited muscular dystrophy of the chicken, is associated with rapid growth of turkeys.

Abstract-Hydrocarbon-inducible cytochrome P4501A (CYP1A) expression was measured, as ethoxyresorufin-O-deethylase (EROD) activity, in livers of wintering harlequin ducks (Histrionicus histrionicus) captured in areas of Prince William Sound, Alaska, USA, oiled by the 1989 Exxon Valdez spill and in birds from nearby unoiled areas, during 2005 to 2009 (up to 20 years following the spill). The present work repeated studies conducted in 1998 that demonstrated that in harlequin ducks using areas that received Exxon Valdez oil, EROD activity was elevated nearly a decade after the spill. The present findings strongly supported the conclusion that average levels of hepatic EROD activity were higher in ducks from oiled areas than those from unoiled areas during 2005 to 2009. This result was consistent across four sampling periods; furthermore, results generated from two independent laboratories using paired liver samples from one of the sampling periods were similar. The EROD activity did not vary in relation to age, sex, or body mass of individuals, nor did it vary strongly by season in birds collected early and late in the winter of 2006 to 2007, indicating that these factors did not confound inferences about observed differences between oiled and unoiled areas. We interpret these results to indicate that harlequin ducks continued to be exposed to residual Exxon Valdez oil up to 20 years after the original spill. This adds to a growing body of literature suggesting that oil spills have the potential to affect wildlife for much longer time frames than previously assumed. Environ. Toxicol.

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