Effect of hemoglobin polymorphism on performance traits in indigenous chicken genotypes in Nigeria

The effect of hemoglobin polymorphism on performance traits in Nigerian indigenous chicken types was investigated in this research. The chickens were obtained through the pure mating of the sire and dam of each population of frizzle feathered, normal feathered, and naked neck chickens to produce F₁ offsprings. One hundred fifty-five chicks (37 frizzle, 79 normal, and 39 naked neck) were measured for body weight (g), breast girth (cm), and tibia length (cm). At 20 weeks, 5 mL of blood was collected from the wing vein of each chicken into heparinized tubes and labeled according to its tag number for electrophoresis. The electrophoresis procedures outlined by RIKEN BRC (2006) was used. 0.6 μl of undiluted blood constituent was taken. The prepared buffer (Tris 10.91 g, EDTA 0.60 g, boric acid 3.10 g) at pH 8.5 was used for the gel preparation. The cellulose acetate membrane was used as a supporting medium. The electrophoresis was carried out at a voltage of 150 V for about 50 min at a temperature of 4 °C. The migration of the genotype was from cathode (-) to anode (+). Each bird was scored as either fast (AA), midway (AB), or slow (BB) according to the mobility on the cellulose acetate paper for hemoglobin. Data were analyzed using statistical analysis system (SAS 2002), and significant means were separated using Tukey's Honestly Significant Difference. Hardy Weinberg's equation was used to calculate genotypic and allelic frequencies and tested using chi-square (χ²). Hemoglobin had three polymorphic forms viz AA, AB, and BB. The genotypic frequencies of hemoglobin (Hb^AA, Hb^AB, and Hb^BB) were 49, 56, and 50, respectively, while the allelic frequencies were 0.50 for both Hb^A and Hb^B. The effect of the polymorphic forms on body weight (g), breast girth (cm), and tibia length (cm) showed that the AA had significantly higher (P < 0.05) body weight (g) than AB and BB (1296.43 g, 1029.59 g, and 884.46 g, respectively). The AA was also higher (P < 0.05) than the AB and BB for breast girth (cm) and tibia length (cm). Heterozygotes adapted and survived better than the homozygotes. The effect of the polymorphic forms of hemoglobin on body weight (g), breast girth (cm), and tibia length (cm) showed that it could be used for body weight selection.