Abstract:
The study was conducted to evaluate the Genotype by Environment interaction for growth and
egg production performances of Kuroiler, Koekoek, Sasso, and Sasso-RIR exotic chicken
breeds and assess chicken husbandry practices under smallholder production system in
Gondar Zuria and Kalu districts of Eastern and Northern Amhara. The survey data were
collected through questionnaires using180 households and analyzed by SAS software of chi- square test while 184 households and four chicken breeds were also included for on-farm
performance evaluation on growth and egg production traits. Data were analyzed by using the
Generalized Linear Model (GLM) procedure of SAS 9.1 by fitting the two districts and four
breeds as main ef ects and the interactions among them. The results showed that the majority
of households (60%) were headed by males. The majority of the respondents (84.5%) had
experience of culling chickens from their flock due to poor productivity (41%), old age (8.9%), sickness behavior (17.7%) and low body weight (16.7%). There was highly significant ef ect of
breeds and districts on body weight of chickens at all growth periods. Sasso chicken breed
was dominant and had the highest body weight compared with the other chicken genotypes
from 90 to 180 days of age in both sexes. Breed by district interaction significantly af ects the body weight of chickens in both sexes at
all growth periods. Breed by district interaction was significantly (p<0.001) dif erent for egg
production performances of chickens at 38
th
, 42
th and 46
th weeks of age. The mean egg
production performance of Sasso (6.25) and Kuroiler (5.75) chicken breeds were produced
higher in Kalu district at 38
th weeks of age. The interaction ef ects of breed by district was
highly significant (p<0.001) dif erence for average egg weight of chicken breeds at 34, 38 and
42 weeks of age in Gondar Zuria district. Sasso breed was recorded the highest (57.68 gram)
egg weight compared to among chicken genotypes at 30
th weeks of age in Gondar Zuria
district. The ef ect of breed by district interaction was highly significant (p<0.001) for mean
age at first egg of four chicken genotypes. The age at first lay of Sasso chicken breed was
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earlier with the shortest age to lay eggs (23.8 weeks) when compared to the other three groups
of genotypes in Kalu district. From this study it is possible to conclude that Sasso breed could
be much suitable than contemporary breeds for meat production while Sasso-RIR breed was
recommended for egg production performance for both districts. Besides, there was breed by
district interactions in body weight, daily body weight gain, egg production, egg weight and
age at first egg lay. Hence, to improve egg production and chicken productivity of the
communities appropriate breed that have positive genotype by environment should be
considered.
