Development of the reproductive system in turkeys with a high or low susceptibility to prolapse of the oviduct.

Lines of turkeys selected for rapid growth and high meat yield have an increased incidence of prolapse of the oviduct compared with unselected or traditional strains of turkeys. The development of the reproductive system and changes in plasma estrogen concentrations were compared in sire line and traditional turkeys with the aim of identifying any morphological or hormonal differences that could be associated with the high incidence of prolapse in the male line. Four turkeys from each strain were killed weekly from 0 to 7 wk postphotostimulation, and samples from prolapsed birds were obtained from field cases. There were no differences in the rate of development of the ovary, oviduct, uterus, vagina, sphincter ani muscle, or muscular cord of the ventral ligament between the two strains that could predispose the sire line to prolapse. Histological investigation of the uterus, vagina, muscular cord of the ventral ligament, and sphincter ani muscle 5 wk postphotostimulation in traditional, sire line, and prolapsed sire line turkeys did not reveal any differences that could be associated with prolapse. No prelay peak in plasma estradiol concentration was observed in either strain, and there was no evidence to suggest that plasma estradiol was higher in the sire line compared with the traditional turkeys. It was concluded that prolapse of the oviduct in sire line turkeys was not associated with any anatomical abnormalities or high plasma estradiol during reproductive development.