Growth rate and feed intake of selected and nonselected broilers.

The relative growth rates and feed intake patterns of selected and nonselected broiler populations were investigated in three trials. The relative growth rate of the selected populations was approximately twice the relative growth rate of the nonselected population during week 1, whereas by week 4 the rates of the selected and nonselected populations were similar. The percentage deviation between populations in feed intake was higher than the percentage deviation in body weights for week 1 in all trials. Feed intake strongly influenced the growth rate of selected and nonselected populations, especially from 3 to 8 weeks of age. The selected populations had superior feed efficiency from 0 to 4 weeks compared to the nonselected population, however, differences between populations from 4 to 8 weeks were not significant.