The influence of genetic changes in total egg production clutch length, broodiness, and body weight on ovarian follicular development in turkeys.

Abstract

Several genetic strains were surveyed for ovarian follicular development after a long production period (120 or 180 days). Hens still in production were killed, weighed, and number and total weight of ovarian follicles in rapid development were measured. The number of atretic follicles and number of follicles developing in pairs (identical and near identical weight) were recorded. Genetic increases in total egg production resulted in no significant change in the number or total weight of the follicles in rapid development after an 180-day production period. There was also no reduction in the number of follicles developing in pairs or the number of atretic follicles. However, genetic increases in average clutch length increased the number of follicles in rapid development with no consistent change in the number of follicles developing in pairs or number of atretic follicles. Genetic decreases in total days lost from broodiness reduced the number of follicles developing in pairs but had no significant influence on total number in rapid development. Both increases in average clutch length and decreases in total days lost from broodiness increased to total number of eggs produced during the first 180 days of egg production. Increasing body weight by selection resulted in a decrease in total egg production and an increase in the number of follicles in rapid development, total weight of these follicles, and the number of follicles developing in pairs.