Reproductive organ morphology and carcass traits in unselected naturally mating female Bronze turkeys at onset of lay

A study was conducted examining the rates of development of components of the reproductive tract during sexual maturation in a flock of naturally mating Bronze turkeys. Birds were processed at 7-d intervals beginning at photostimulation (29.5 wk of age), for the following 5 wk, and following their first oviposition. The relatively low BW of this strain (6.6 kg) was associated with a very low lipid content (16.4%), abdominal fat pad weight (107 g), and breast muscle weight (1.15 kg). At sexual maturity the ovary contained 12.2 large yellow follicles with 59% of these follicles being in a multiple hierarchy arrangement. There was an average of 1.4 unreconciled POF (the remnant of the site of ovulation). The presence of unreconciled POF suggests that this may be a natural phenomenon in turkeys and not limited to modern fast growing strains. Birds that laid their first egg quickly were more likely to have ovulated several times prior to their first oviposition than birds commencing lay later (r = 0.64; P < 0.02). Regression analysis of reproductive tract development revealed that the oviduct reached its mature weight 3 d earlier than did the ovary (28.3 vs. 31.2 d) (r2 = 0.81; P < 0.0001). This strain resembled modern female line strains in regard to reproductive traits. Key words: Bronze Turkey, body weight, ovary morphology, reproductive disorders