Major genes and phenotyping of indigenous chickens of the western highlands of Cameroon.

The Western highlands of Cameroon (WHC) are known for their diverse indigenous chicken phenotypes (ICW), making it difficult to report their performance and adaptability attributes accurately. A study was conducted on 828 adult ICWs sampled from the Noun and Menoua administrative divisions, representing 61% of the surface area of the WHC. The study developed a standardised method for identifying and recording the chickens' traits, including body weight, feather and appendage colour, and associated genes. Based on this data, the chickens were grouped into various "morphotypes" based on their gene combinations. One hundred twenty-five morphotypes were identified and recorded with informative Identifying ID codes. The study found that the significant genes affecting morphotype assignment included two multiallelic genes for plumage colour (10 alleles), plumage colour modifiers (7 genes), plumage colour dilution and enhancers (6 genes), plumage type and distribution (10 genes), comb type (4 genes), comb colour (1 gene), skin, tissue, and shank colour (4 genes). Additionally, ICW body weight varied from light to heavy and was affected by sex and localities (P ≤ 0.05). ICW are primarily medium size including 15% of cocks and 19% of hens in Menoua versus 20% cocks and 47% of hens in the Noun. Heavier chickens are more frequent in Menoua (23% and 7.4% for cocks and hens) than in Noun (2.7% and 11%), whereas Medium and light weight are more frequent in Noun. The study also revealed that the MC1R locus was the most frequent plumage colour determinant (92%), with the autosomal red plumage (E*WH) being the most commonly observed (17.8%) in the Noun division. The black plumage (E) was the most represented (13.10%) in the Menoua division. Overall, this study provided a standardised identification system for indigenous chickens in the WHC and an original methodology for their knowledge and record system.