Phenotypic characterization of local chicken Ecotypes in the central zone of tigray in Northern Ethiopia

Abstract

The study was conducted in three districts of central zone of Tigray, with the aim to assess the socioeconomic characteristics and production environments of local chicken ecotypes, along with farmers’ breeding objectives, breeding practice, and traits of preference for local chickens and to assess the phenotypic characteristics of the local chicken. A total of 242 chicken owners were selected for the study. Nine qualitative and nineteen quantitative traits from 457chickens were considered. The research finding revealed that village chicken production seems to be an important activity with an average flock size 9.41 and 8.98 birds per household in midland and highland agro ecology. The most important chicken production system of the study area is traditional with small feed supplementation. A separate house to keep chicken was practiced in 36.8% and 28.9% of the respondents in highland and midland area, respectively. About 87.6% of the respondents select eggs for incubation and straw was commonly used as bedding material. About 96.7% of the respondent use broody hens for incubation and rearing chicks. About 81% of households participate in chicken and egg marketing as a source of income. Culling is practiced by 78.9% of households based on production level of chicken, age, plumage color, ill and bad temperament of hens and cocks. The main breeding objectives of the respondents were meant for household consumption, income generation and for replacement of the flock. The effective population size (Ne) and the rate of inbreeding (ΔF) calculated for the indigenous chicken flock of the study area were 3.99 and 0.13, respectively.The selection criteria used for selection of breeding hen were egg size, plumage color, broodiness, disease resistance and hatchability with an average index value of 0.067, 0.064, 0.062, 0.054, 0.042. The highest selection criteria used for selection of breeding cock were egg number of the dam, comb type, plumage color, and disease resistance, egg size growth rate with an index value of 0.053, 0.052, 0.045, 0.044, 0.041 and 0.041, respectively. Farmers preferred traits like comb type, plumage color, egg size, broodiness, disease resistance, meat quality, fertility growth, egg number and body size with indices of 0.169,0.156,0.137,0.117,0.114,0.113,0.108,0.096 and 0077, respectively. Reproductive performance study revealed that the overall mean age at first mating of male chickens and the age at first egg of female chickens were 5.29 and 5.96 months. Local chicken were mostly normally feathered (hens 97.8%, cocks 96%), red (33%), grayish (17.5%), brownish (17.3%) colors. Morph metric measurements indicated that significance differences (P<0.05) were observed between agro ecology with respect to breast width, spur length, chest circumferences and shank length. In all parameters, male shows higher significance (P<0.001) value than female except breast width and beak width. Multivariate analysis result showed that five PC were extracted that accounted for 58.45% of the total variation. The differentiation of highland and midland populations was apparent based on the weights of neck length, beak length, body length, wattle width, body weight, wattle length and height at back traits. The Mahalanobis’ distances between populations shows the smallest and largest distances between highland and midland chicken ecotypes. In conclusion, there is diversity of indigenous chicken population and farmers’ preference for specific traits that may invite to design community based genetic improvement.