Effect of protein and energy levels on performance and carcass rate in cross bred chicks.

Extension Planning Division, R.D.A., KoreaABSTRACT The experiment were protein and metabolizable energy level in performance and carcass rate in cross bred chicks. One day old, 720 male and female cross bred chick were used for the experiments, and 20 chicks were placed at each pen. The energy level of feed was maintained about 2,950, 3,000, 3,050 kcal/kg, and protein content was adjusted about 19, 20, 21% from 0 to 5 weeks and energy level was maintained about 3,100, 3,150, 3,200 kcal/kg, and protein content was adjusted about 17, 18, 19% from the 6 to 10 weeks old of the experiment. At the whole time, ME 3,100 (2,950), 3,150 (3,000) and 3,200 (3,050) kcal/kg treatment groups was not significant difference in weight gain, feed intake, but 3,150 (3,000), 3,200 (3,050) kcal/kg treated groups revealed to show improved feed conversion rate than the group treated with ME 3,100 (2,950) kcal (P<0.05). And CP 17 (19), 18 (20), 19 (21)% treatment groups did not significant difference weight gain and feed intake but CP 19 (21)% treated group wan significant difference feed conversion rate than the CP 17 (19)% treated group (P<0.05). ME level of 3,100 (2,950), 3,150 (3,000), 3,200 (3,050) kcal/kg treatment groups in carcass rate and abdominal fat rate was not signficant difference and protein of 17 (19), 18 (20), 19 (21)% treatment groups after end of experiment. Between ME and CP of dietary was significant appeared to interact at 6～10 weeks (P<0.05).(Key words : cross bred chicks, ME, CP, performance, carcass rate)