Distribution and Retention of Spermatozoa with Acrosomal and Nuclear Abnormalities in the Cow Genital Tract2

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Abstract
Two experiments were conducted to evaluate the fate of sperm following uterine insemination. In Exp. I, five pairs of Holstein cows were inseminated with egg yolk-Tris extended semen (∼1.O × 109 sperm; .5 ml) from five ejaculates from a single bull that had high levels (∼70%) of morphologically abnormal sperm. Cows were slaughtered 12 h after insemination. The genital tracts were removed and promptly clamped into defined regions. Sperm were recovered by flushing with 2.9% sodium citrate buffer. Proportions of abnormal sperm in the various regions were compared with those in the inseminate. Sperm numbers were also determined from each region. Regions of the tract varied in number of sperm (P<.001), proportions of knobbed acrosomes (P<.001), tapered heads (P<.001), protoplasmic droplets (P<.001), tail abnormalities (P<.029) and total abnormalities (P<.002). A total of 63.5 ± 6.4 × 106 sperm was recovered. These sperm were distributed throughout the tract as follows: vagina, 91.8%; cervix, 5.4%; uterine horns, 2.7%, and uterotubal junctions-isthmi, .04%. No sperm were recovered from ampullae. Because retrograde movement of sperm from the uterus occurred in Exp. I, we conducted Exp. II to determine the extent of sperm loss from the genital tract following insemination. Three pairs of Holstein cows were inseminated with .42 × 109 sperm (.5 ml; egg yolk-Tris extender) from the same bull used in Exp. I (three ejaculates). All discharged mucus and urine was collected for 12 h after insemination for recovery of sperm. Aspirates (∼1 ml) of mucus from the vagina were evaluated during the 12-h post-insemination period for numbers of sperm and leucocytes. Sperm were also recovered from the tract following slaughter (∼12 h) to determine retention. Overall, 73 ± 3.7% of inseminated sperm were recovered. Components were: inseminate lost from the genital tract in discharged mucus, 60 ± 4.6%; lost in urine, .06 ± .02%; aspirated from the vagina, 4.4 ± 1%; adhered to equipment, 1.3 ± .3%, and retained in the genital tract, 6.5 ± 1.6%. Predicted numbers of sperm contained in discharged mucus 2 h post-insemination were greater (P<.009) than at subsequent hours. Sperm numbers in the uterotubal junction-isthmus (16 cows) were highly related to numbers in the uterus (r=.71; P<.003) and vagina (r=.64; P<.009) at 12 h post-insemination, but not to numbers in the cervix (r=.06; P=.83) or in the inseminate (r=.09; P=.76). It is concluded that proportions of sperm with knobbed acrosomes were reduced in the cow genital tract compared with proportions in the inseminate, and that large retrograde losses of sperm from the genital tract occurred following uterine deposition of semen. Copyright © 1985. American Society of Animal Science . Copyright 1985 by American Society of Animal Science.

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