Effect of Sperm Numbers per Insemination Following Early or Late Initial Inseminations in Turkeys

Abstract

Large White turkey hens were used in this study to investigate sperm storage in the hen throughout a 20-week breeding cycle. Hens were initially inseminated early or late and subsequently at 7-day intervals with either 20, 50, or 100 million sperm each time. Early inseminations (EI) were performed on Days 14 and 17 postlighting, and the late inseminations (LI) were performed on Days 21 and 24 postlighting. Fertility (percent) was calculated weekly for 20 weeks following the second initial insemination in each group. Fertility was greatest in EI hens for the 20-week period; the largest difference occurred between EI and LI treatments of the 50 million sperm/insemination group. A significant interaction was observed between time of initial insemination and sperm numbers per insemination. Overall fertility was improved with each increase in sperm numbers/insemination.

Efficacy of Fertilization in Artificially Inseminated Turkey Hens

“…When storage sites were filled in the 50m or 100m treatments, acceptable fertility was noted early in the laying cycle; however, as hens aged, fertility fell to unacceptable levels, and hens relied more on spermatozoa from initial AI for fertility. The fact that AI of 50 million cells/ wk failed to maintain adequate fertility contradicts the hypothesis of Mclntyre et al (1986), that storage capacity of the oviduct may be 50 million cells/wk following initial AI that fills the oviduct. Because 50m treatment hens relied more than 200m treatment hens on spermatozoa from initial AI for fertility, Christensen's (1981) hypothesis that subsequent AI act to keep spermatozoa in storage sites is supported.…”

“…An AI tech- Mclntyre et al (1982) proposed that AI could be more efficient if spermatozoa storage sites of the turkey hen were filled initially. In a subsequent study, Mclntyre et al (1986) proposed that filled storage tubules may release newer stored cells more readily. When storage sites were filled in the 50m or 100m treatments, acceptable fertility was noted early in the laying cycle; however, as hens aged, fertility fell to unacceptable levels, and hens relied more on spermatozoa from initial AI for fertility.…”

“…The second treatment group of 48 hens received 50 million spermatozoa/hen per wk (50m). The 50m treatment examined the hypothesis pro- posed by Mclntyre et al (1986) that 50 million spermatozoa/wk would maintain fertility following proper initial AI. The remaining group of 48 hens received 200 million spermatozoa/ hen per week (200m) as in Trial 1.…”

“…In the second, spermatozoa storage capacity of the oviduct remains constant throughout lay and maximum fertility results after weekly artificial insemination (AI) of 200 million cells (Sexton, 1977). In the third, spermatozoa storage capacity of the turkey oviduct was approximately 50 million spermatozoa/wk (Mclntyre et al, 1986), when inseminations of 50 million followed larger inseminations performed prior to the onset of egg production.…”

Turkey hen fertility and egg production after artificial insemination and multiple oviduct eversion during the pre-laying period

“…Artificial insemination (AI) of turkey hens before the onset of egg production generally results in higher hen fertility than in hens inseminated initially after the onset of egg production (Mclntyre et al, 1982(Mclntyre et al, , 1986. Although the physiological basis of these observations has not been established, Mclntyre et al (1982) suggested that there is "... an increased receptiveness of the hen's oviduct to spermatozoa during the time that natural mating frequency is highest".…”