The effects of genetic selection on production parameters of single comb white leghorn hens

Four commercial table egg genetic stocks consisting of the Ottawa Control S trains 5, 7, and 10 (CS5, CS7, and CS10) and the 1993 H&N "Nick Chick" (CCS ) were housed in the same environment and compared for production character istics. These birds were housed in an environmentally controlled laying fac ility with trideck cages. Feed consumption, egg production, and mortality w ere monitored daily and compiled every 28 d. The study was conducted for tw o egg production cycles, including the molt period. Body weight was progres sively lower for the more modern strains with CS5 being the heaviest and CC S maintaining the smallest body weight throughout the production periods. T he CCS had the highest (P < 0.0001) hen-day production rate, which resulted in the greatest daily egg mass among the strains. The CCS consumed the gre atest amount of feed and exhibited the highest gross egg income among the s trains. We concluded that genetic selection has improved production paramet ers in commercial layers as determined by measurements in this study.