A comparative study of some performance characteristics in Cobb and Ross broiler strains fed three rations in which PKOR replaced wheat bran at 0% (control), 10% and 20%. Each of the three treatments, had three replicates of 25 birds (total of 450 birds; 225 each of Cobb and Ross), in a completely randomized design experiment. The trial involved 3 week old broiler chicks over 5 week period. The effects of genotype, ration and their interactions on some growth parameters, carcass traits, haematological and serological parameters were assessed in a 3x2 factorial arrangement. The effects of genotype on most of the haematological and serological parameters evaluated was not significant (p>0.05). On the other hand, there were significant (p<0.05) ration effects on major growth parameters; Control birds (0% PKOR) had significantly higher (p<0.05) final live weights compared with lower but similar weights (p>0.05) for birds on 10% and 20% PKOR rations. This trend and significance level were reflected in other growth parameters such as weight gain and growth rate. FCR was however, significantly lower (p<0.05) in the control and 20% birds, than birds on the 10% treatment ration. The effects of genotype × ration interactions on all performance parameters assessed were not significant (p>0.05). Feed cost/kg weight gain declined progressively from the control (GH¢15.60) to birds fed rations containing 20% of PKOR (GH¢12.76), although differences were not significant (p>0.05). Furthermore, birds on 0% PKOR recorded significantly (p<0.05) higher warm carcass weight and warm dressing percentage than birds fed 10% and 20% PKOR; chilled carcass traits assessed were however similar (p>0.05) for all dietary treatments. All haematological parameters evaluated did not show significant differences (p>0.05) across treatments, except for the WBC counts; birds on 0% and 10% PKOR recorded significantly higher (p<0.05) WBC counts than birds on 20% PKOR rations. Serum biochemical parameters measured did not vary significantly (p>0.05) among the three dietary treatments. The absence of genotype × ration interactions in this study implies that farmers can raise any of the two broiler genotypes on any of the three rations offered without any detrimental effects on performance or production, provided nutritional composition of diets was adequate for requirements of birds in that category. With the reduction or savings in feed cost/kg weight gain (of GH¢1.68 and GH¢2.84 for 10% and 20% PKOR replacing wheat bran), farmers would increase their profit margins, if they used PKOR in rations for Cobb and Ross genotype of broilers.