BREEDING AND GENETICS Influence of Selection for Increased Body Weight, Egg Production, and Shank Width on the Length of the Incubation Period of Turkeys1

ABSTRACT An experiment was designed to study the influence of selection for increased 16-wk BW (F line), egg production (E line), and shank width (FL line) in turkeys on length of the incubation period and to estimate the influence of adult BW (BW50) and egg weight on the incubation period. The base populations for the F, FL, and E lines were randombred control (RBC)2, F, and RBC1, respectively. An additional RBC (RBC3) was also in-cluded in the study. The experimental turkey lines differed in length of the incubation period in all trials, indicating genetic differ-ences exist. The E line, in general, had a longer incubation period than the RBC1 line, due to an increase in the time required for external pipping. The FL line had a longer period of incubation than the F line. Differences in the length of the incubation period between the F and RBC2 lines were inconsistent. The F line had a shorter incuba-tion period than the RBC2 line in Trial 1, whereas there was no difference between lines in Trial 2. In Trial 3, the (Key words: turkey, incubation period, egg weight, body weight, genetic differences