Determination of growth performance of crossbred Korean native chickens for twelve weeks after hatching

The study was conducted to evaluate the growth performance, viability, and uniformity of female crossbred Korean native chickens (KNC) for the first twelve weeks after hatching. Six crossbreed lines of chickens (1B, 2B, 3B, 4B, 5B, and 6B) bred from 1 paternal line and 6 maternal lines of KNC were compared in this study. Sixty newly hatched 1-day old chicks from each crossbreed, for a total of 360 chickens, were allocated into 6 replicates (10 birds per replicate) in a complete randomized design. Experimental diets used in this study consisted of 3 phases: 1) week 0 to 5, crude protein 20.3% and metabolizable energy 3,059 kcal/kg; 2) week 5 to 8, crude protein 18.6% and metabolizable energy 3,123 kcal/kg; and 3) week 8 to 12, crude protein 16.7% and metabolizable energy 3,187 kcal/kg. Body weight and feed intake were measured bi-weekly during the experiment. The 4B crossbreed had a higher body weight, average daily gain, and average daily feed intake on week 12 (p < 0.05) than the other groups. The 4B crossbreed had a lower (p < 0.05) uniformity during weeks 10 to 12 than crossbreeds 1B and 5B. However, a lower viability was observed (p > 0.05) in 4B in weeks 2 to 12 than those in the other groups. Results of the current study indicate that the 4B crossbreed had a higher growth performance in week 12 but had a lower viability for weeks 2 to 12 than the other crossbreeds.