The biphenyls tested with caged White Leghorn pullets were polychlorinated biphenyl (PCBs) Aroclors 1232, 1242, 1248, 1254 and 1016 and polybrominated biphenyl (PBB) PBP-6 at the 5, 10 and 20 p.p.m. levels. These pollutants exerted no adverse effects on egg production, egg weight, egg shell thicknes...