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pubmed:abstractText |
Laying hens and roosters were given rations containing 0, 5 or 50 ppm of polychlorinated biphenyls (PCB) as Aroclor 1254 for up to 39 weeks. Due to drastic decline in production and hatchability of fertile eggs, the 50 ppm treatment was replaced with control ration at 14 weeks and the residual effects were investigated. Following the withdrawal of PCB from the ration, the affected parameters slowly returned to the control range. The 5ppm level of PCB reduced egg production but not hatchability of fertile eggs. Fertility for the 5ppm PCB group in the first 14 weeks was similar to the other groups but showed a significantly greater decline in the last 14 weeks. Concentration of PCB in eggs of both treatment groups increased until maximum concentrations were reached. These maxima persisted until the end of the experiment or until the withdrawal of PCB from the ration. Following withdrawal of higher level of PCB, the PCB declined in concentration but persisted in eggs over a five month period.
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