Abstract

A study was carried out to evaluate genetic potential of two chicken ecotypes of Tanzania viz. Kuchi and Medium managed both under intensive and extensive management systems. Traits studied under intensive conditions included body weights at 8 (Bwt8), 12 (Bwt12), 16 (Bwt16), and 20 (Bwt20) weeks of age, age at sexual maturity (AFE), egg number in the first 90 days after sexual maturity (EN-90), egg weight (EW), eggshell thickness (STH), egg shape index (ESI), while under extensive management it involved only body weights at various ages. There were significant differences between ecotypes with respect to body weights (P < 0.001), EW (P< 0.05) in favour of Kuchi; and EN-90 (P < 0.05), AFE (P < 0.05) in favour of Medium ecotype. However, differences between ecotypes with respect to STH and ESI were not significant (P > 0.05). Bwt8, Bwt12, Bwt16 and Bwt20 under intensive management averaged over both sexes for Kuchi and Mediumecotypes were 490 and 404 g; 954 and 776 g; 1394 and 1183 g and 1647 and 1447 g, respectively. Corresponding body weights under extensive management were 348 and 273 g; 685 and 581 g; 974 and 845 g; 1188 and 1046 g, respectively. Average AFE, EN-90, EW, and ESI under intensive managements forKuchi and Medium ecotypes were 173 and 168 days; 45 and 49 eggs; 45 and 42 g; 75 and 74%, respectively, while average STH in both ecotypes was around 37 µ. From these results, it was concluded that Kuchi was superior to Mediumecotype in terms of body weights and converse was true for most of egg production and related traits, and further that their performance can further be improved by improving both management system and improving their genetic potential through within ecotype selection. Since Kuchi ecotype was superior toMedium ecotype in terms body weights and opposite was true for Mediumecotype in terms of most egg production and related traits. Therefore, Kuchiecotype could be good starting genetic material for further improvement in body weight, and Medium ecotype in egg production traits.

Key words: Body-weights, egg-traits, chicken-ecotype.