Abstract:
A poultry bird defeathering machine was designed and fabricated in the Department of Agricultural
and Environmental Engineering, Federal University of Technology Akure for small scale poultry
processors. The machine consisted of a feather plate on which plucking rubbers are arranged, a
defeathering chamber on which plucking fingers are set in an array and was powered with a 2kW
electric motor. The machine was tested at three operating speeds of 200, 280 and 360 rpm, which
were obtained using belt and pulley drived over transmission systems. Isa brown chicken which
were old layer birds (spent hens) were tested in the machine at five scalding temperatures which are
normal room temperature, 30, 50, 70 and 100°C. In order to evaluate the effect of machine speed
and scalding temperature on the feather retention on birds, the plucking efficiency, and the
defeathering time of each bird. Data obtained were recorded and presented in tables and graphs.
Results showed that the feather retention rate and defeathering time decreased with increased
operating speed, while plucking efficiency increased with speed. However, an ANOVA test show
the result of 0.72, 0.72 and 0.32 respectively indicated that the effects were insignificant.
Furthermore, the scalding temperature had significant effect on the evaluation parameters as the
feather retention was seen to decrease with increase in temperature, same with the defeathering time,
but the plucking efficiency increased with scalding temperature up till 700C and reduce afterwards.
The highest plucking efficiency of 98.5% was obtained at 360 rpm speed and 100°C scalding
temperature. Based on physical evaluation and the results obtained speeds of 280 rpm or higher were
recommended to operate the machine and the scalding temperature of 70°C is recommended
