Phenotypic characterization of local chicken ecotypes in western zone of Tigray northern Ethiopia

Abstract

The study aimed to characterize local chicken ecotypes in terms of phenotype in Western Zone of Tigray. Multi-stage sampling procedures were employed to select sample kebeles and respondents. Administration of pretested questionnaire and measurement of morphometric traits from 770 local chickens were employed. Qualitatitive traits of 1642 local chickens were observed and recorded. Forty eight matured local chickens of both sexes were used for carcass trait evaluation. Functional traits were studied through monitoring of randomly selected chicken owners and structured questionnaire. Qualitative chicken traits and qualitative data of the survey were analyzed using descriptive statistics of SPSS 16. KruskalWall’s test option of Non-parametric tests of SPSS 16 was employed to test proportion difference of each variable among the agro-ecologies. Quantitative, carcass and performances traits among the three agro-ecologies were analyzed by general linear model of SAS 2008 and Tukey mean comparison was employed for significantly different traits among agro-ecological zones. Multivariate analysis of principal component analysis, canonical discriminant analysis, step wise discriminant and cluster analysis using 21-quantitative traits were performed by SAS 2008 for males and females chicken ecotypes separately. The overall mean live weight of matured male and female chicken was 1.569±0.004kg and 1.261±0.004 kg, respectively. The overall mean dressing percentage of local male and female chickens was 66.82±0.3 and 63.43±0.03 respectively. The average age of sexual maturity of local male and female chickens was 5.71±0.03 and 7.19 ±0.04 months, respectively. The overall hatchability of eggs was 74.37±0.57 %. Red (51.2%), Gebsima (18.2%) and Anbesima (8.9%) were the most frequent dominant plumage colors in the study area. Disease (1st) and predators (2nd) were the major village chicken production constraints. On the other hand, market and feed access were the two pronounced opportunities of village chicken production. Earlobe length, wingspan, skull length and shank length were most important traits for discriminating among female chicken ecotypes while wingspan, neck length, earlobe length, spur length, body length and shank length were most important discriminatory traits among male chicken ecotypes.97.3% of female and 100% male chicken ecotypes were correctly classified with error rate of 2.7% and 0%,respectively.Based on GLM analysis, morphological variations, multivariate analysis and focused discussion groups, the local chicken ecotypes of western Tigray classified as lowland, midland and highland chicken ecotypes. Plumage color (1st), egg laid/clutch (2nd) and comb type (3rd) were the most preferred attributes used for selection breeding chicken. Egg laid/clutch (1st), body weight/growth (2nd