Synopsis
Large‐type White turkey hens from a flock with a record of low “fertility” (live embryos at 7 to 10 days’ incubation) were distributed randomly into four groups of 50 hens each and were given treatments involving antibiotic and inseminations on a weekly or fortnightly schedule. During the first 5 weeks of the experiment, semen was introduced, via a plastic tube, at least 5 cm. into the oviduct of all birds in each group. Irrespective of the type of treatment, there was a significant rise in “fertility” in all groups. This was sustained for a 4‐week period, with the highest “fertility” occurring in the group inseminated weekly. When shallow insemination was used with two groups, “fertility” over a second 4‐week period was lowest in these two groups. Since percentage infertile eggs could account for the major share of the decline in percentage live embryos, it is postulated that the low live embryo percentage existing previously in the flock resulted from insufficient numbers of spermatozoa being inseminated rather than from a reaction to an unidentified pathogenic agent, as frequently suspected.