Pregnancy rates in mares inseminated with 0.5 or 1 million sperm using hysteroscopic or transrectally guided deep-horn insemination techniques

Abstract

Placement of sperm deep in the equine uterine horn allows fewer sperm to be inseminated while maintaining acceptable fertility, and has been promoted for use in circumstances when fertility would be expected to be low if standard insemination were used (e.g., semen from a subfertile stallion, or frozen-thawed semen). Two main techniques, transrectally guided (TRG) and hysteroscopic (HYS) insemination, have been developed for this purpose; however, there is some controversy regarding their comparative efficacy. This study was conducted to compare pregnancy rates when mares were inseminated by TRG or HYS, using sperm numbers approaching and under the minimum threshold, resulting in reduced fertility. When 1 × 10(6) sperm were inseminated, pregnancy rates were not different (P > 0.10) between techniques HYS (10/13, 77%) and TRG (11/15, 73%). Similarly, when 0.5 × 10(6) sperm were inseminated, pregnancy rates were not different (P > 0.10) between techniques HYS (3/15, 20%) and TRG (4/13, 31%). Combined pregnancy rates for the two treatments were 13/28 (46%) for HYS and 15/28 (54%) for TRG (P > 0.10). Pregnancy rates using a subthreshold number of sperm were not significantly affected by a deep-horn insemination technique.

Effect of different types of artificial insemination and semen dose on reproductive efficiency in mares

“…Our data allow us to conclude that the semen deposition site (CAI or DAI) and the concentration do not affect the fertility rates, but CAI is easier and faster to perform. However, when the availability of semen is restricted, DAI should be used because it is efficient even at low doses of PMS and allows for insemination of more mares to the same stallion (Hayden et al, 2012).…”

“…With these approach a semen dose of 100 ×10 6 PMS per insemination is used (Xavier et al 2009), the minimum quantity being 50 ×10 6 (Householder et al, 1981). Another approach is AI by hysteroscopy, where deposition of semen is performed at the junction of the uterustubal papilla (Blinsko et al 2003, Sieme et al 2004, Hayden et al 2012.…”

Geburt eines Fohlens nach Besamung mit tiefgefrorenen Nebenhodenspermien und zeitgleicher intrauteriner Verabreichung von homologem Seminalplasma

“…Es wäre daher auch in diesem Fall möglich gewesen, die Spermien durch eine höhere Verdünnung auf mehr Pailletten aufzuteilen und dadurch mehr Portionen für die tief intrauterine Besamung zu produzieren. Mithilfe der hysteroskopischen Besamung konnten die gleichen Trächtigkeitsraten erzielt werden wie bei Verwendung eines flexiblen Besamungskatheters, der transrektal geleitet bis zur Uterushornspitze vorgeführt wird [13]. Aufgrund des geringen technischen Aufwands und der rasch durchführbaren Besamung wurde im vorliegenden Fall eine flexible Besamungspipette verwendet.…”

Effect of Different Dilution Methods and Ratios of Ram Semen on Sperm Parameters after Cryopreservation

“…This reduction diminishes the protective ability of spermatozoa, resulting in a dilution effect and a shortened effective preservation time of semen [ 11 ]. Excessive dilution rate can lead to a decrease in spermatozoa density and the number of effective spermatozoa while increasing the insemination volume, and due to the unique structure of the sheep’s reproductive tract, the increase in semen volume can exacerbate the reflux of spermatozoa from the cervix, ultimately reducing the pregnancy rate [ 12 , 13 ]. Therefore, it is crucial to find the appropriate dilution method and ratio for semen preservation and AI.…”