Abstract
A study was conducted to evaluate the possibility for the production of white and colored
feathered meat chicken using locally available genetic resources in Bangladesh. To achieve
the objectives four studies were conducted. In the 1st study, the performance of locally
available chicken genotypes such as Synthetic White Broiler (SWB), Synthetic Color Broiler
(SCB), White Plymouth Rock (WPR), Rhode Island Red (RIR), Aseel (As) and As x RIR
crossbred (As-RIR) were evaluated for their performance. In the 2nd study, three
generation of selection were performed on SWB, SCB, As-RIR and WPR. The male lines
were selected on 5 week body weight, while the female lines on index value computed on
early body weight, 32 week egg weight and egg number up to 35 weeks of age. In study
3to the estimate heterosis, 2 and 3-way crossing was performed and a total of 420 and 173
DOCs were hatched for white and colored feather broilers. Heritability of early growth
and reproductive traits was estimated. Standard feeding and management procedures
were followed for meat chickens. The parameters recorded were body weight, feed
consumption, age at sexual maturity, body weight at sexual maturity, egg weight at sexual
maturity, weekly egg weight, egg production, meat yield, and livability. In the 1st study,
significantly (p<0.05) higher body weight (g) at 5 weeks was observed in SWB
(817.08±3.57) followed by SCB (501.44±7.70), RIR (275.04+16.41), As-RIR (261.15±6.65), As
(249.94±17.58) and WPR (230.88±3.47 g). The weight gain up to 5 weeks of age were
771.66±3.55, 459.46±7.66, 240.93±16.33, 229.34±6.60, 218.25±17.49 and 196.45±3.46 g in SWB,
SCB, RIR, As-RIR, As and WPR, respectively. The feed conversion ratio was better in SWB
(2.06) and lower in As (3.44). Significantly (p<0.05) higher egg production was found in
As-RIR and SCB followed by WPR and lower in SWB and As. The dressing meat yield was
significantly (p<0.05) higher in As-RIR (75.26±0.17) followed by As (75.03±0.50), RIR
(72.12±0.52) and SCB (71.71±0.17) and lower in SWB (70.82±0.17) and WPR (70.89±0.17).
The overall livability (92.02 to 96.58%) up to 35 weeks of age was almost similar in all the
genotypes. Selection significantly (p<0.05) improved body weight and weight gain
irrespective of the genotypes of chicken. After three generations of selection the body
weight at 5 weeks of age of different genotypes of chicken were 988.46±0.94, 550.09±0.30,
350.53±0.11and 329.96±0.14 g in SWB, SCB, WPR and As-RIR, respectively. The weight
gain per generation was 43.05, 30.51, 17.97 and 12.42 g in SWB, WPR, As-RIR and SCB,
respectively and the difference was significant (p<0.05). Shank length, keel length and
breast width of genotypes improved through selection. Similarly, the selection also
improved the reproductive parameters like egg production, egg weight with different rates
in genotypes. The heritability of early body weight of the genotypes, SWB, SCB, WPR and
As-RIR was moderate and ranges from 0.28±0.08 to 0.42±0.12, whereas for the reproductive
traits of egg weight (EW32) and egg number (EN35) ranges from 0.33±0.05 to 0.41±0.06 and
0.40±0.05 to 0.41±0.06, respectively. The realized genetic gain in body weight was the
highest in SWB (72.33 g) followed by WRP (42.72 g), As-RIR (27.31 g) and SCB (16.89 g)
during 5 weeks of age. The genetic gain of EN35 was 6.51 eggs in SWB and 4.22 eggs in
WPR. The mid-parent heterosis of white and color chicken in 2-way crosses of WPR x SWB
were 40%, whereas in As-RIR x SCB, it was 38%. The heterosis of body weight and weight
gain in a 3-way cross was 70% and 74% in the SWB2×F1 crossbred, respectively. The body
weight in 3-way crossbred was significantly (p<0.05) higher in SWB2×F1 (1483.47±2.19 g)
than F₁x SWB2 (1370.71±8.80 g)at 5 weeks of age. So, it may be concluded that the 2-way
color crossbred (As-RIRXSCB) and 3-way white crossbred (SWB2×F1) may be used for
commercial meat production in Banglad