Sexual Dimorphism in Predicting Body Weight of Two Broiler Strains

A study was carried out to determine if the relationship between liveweight and linear body measurements, as well as predictability of both liveweight and linear body measurements were influenced by sex in two strains of broiler chickens (Arbor Acre and Anak). One hundred and twenty day old broiler chicks comprising sixty two males and fifty eight females were used in the study. The birds were wing tagged at day old. Liveweight and linear parameters such as wing length (WL), thigh length (TL), drumstick length (DL), shank length (SL), body length (BL), body girth (BG) and keel length (KL) were measured on individual birds fortnightly (at day old, 2, 4, 6 and 8 weeks). The result of the study showed that sexual dimorphism existed in the relationships between liveweights and linear measurements at 2, 4, 6 and 8 weeks of age in the Arbor Acre broilers, while in Anak broilers the effect of sex was significant at 2 weeks and 8 weeks of age only. Sex influenced the linear body measurement (wing length, thigh length, drumstick length, shank length, body length, body girth and keel length) that could predict liveweights at all ages in the Arbor Acre and Anak broilers

Diallel Analysis for Bodyweight Involving Three Genotypes of Nigerian Indigenous Chickens

To evaluate heterosis, reciprocal effect, general and specific combining abilities for bodyweight, a diallel crossing experiment was conducted using three genotypes of Nigerian indigenous chickens: normal (N), frizzle (F) and naked-neck (Na). A total of 601 chicks was hatched from all possible matings between the three genotypes. The chicks used in this study were hatched from a foundation stock of 90 chickens comprising 25 hens and 5 cocks for each of the three genotypes. A mating ratio of 1 male : 5 females was employed. Furthermore, data on bodyweight were scrutinized with complete diallel analysis after they had been corrected for significant effects of hatch of birds using least squares constants. The results revealed that bodyweight (BWT) was significantly influenced by genetic groups with the frizzle-naked (FNa) having the best performance at all ages (4 - 20 weeks) except at hatch, with a mean final BWT of 1173 g at 20 weeks old. The next best performing was its reciprocal, the naked-frizzle (NaF), with a mean final BWT of 1162 g. Furthermore, the FNa gave the best estimates for heterosis and specific combining ability, while the F and NNa gave the best estimates for general combining ability and reciprocal effect, respectively. Therefore, the F genotype as sire and the Na as dam provided the most suitable combination for improved BWT. Furthermore, the use of the Na genotype as dam was more suitable owing to the significant reciprocal effect.Keywords: Combining Abilities, Frizzle-Feathered, Heterosis, Naked-Neck, Normal-Feathere