Effect of freezing semen and dosage of sperm on number of accessory sperm, fertility, and embryo quality in artificially inseminated cattle1

Abstract

This experiment was conducted to determine whether use of fresh or frozen semen at either 20 x 10(6) (low) or 100 x 10(6) (high) sperm per dose affects the number of accessory sperm and fertilization status/embryo quality as determined from ova/embryos recovered nonsurgically 6 d after insemination. Ejaculates of four bulls were split and prepared for use as fresh or frozen semen at either the high or low dose. From 129 inseminations to normally cycling cows, 98 ova/embryos were recovered. To reduce male effects, ova/embryos used were randomly balanced across treatments, by ejaculate within bull for evaluation of frozen vs fresh semen (n = 80) and by bull for evaluation of high vs low dosage treatments (n = 76). Distribution of accessory sperm was highly skewed downward; thus, median values were more meaningful than means. Freezing semen had no significant effect on fertility status/embryo quality or number of accessory sperm at either dosage. Increasing dosage improved the number of accessory sperm per ovum or embryo (median value) and fertility status/embryo quality (P < .05). Mean +/- SD and median values for accessory sperm were 37.8 +/- 38.3 and 27.5; 28.9 +/- 62.8 and 3.0 for the high and low dose, respectively. Percentage of unfertilized ova, degenerate embryos, and embryos classified poor to fair and good to excellent were 3, 5, 24, 68, and 21, 16, 18, 45, for the high and low dose, respectively. We conclude that number of accessory sperm and fertility status/embryo quality respond favorably to increased dosage of semen and that freezing semen in this study was not detrimental to these parameters.

In vitro and in vivo quality of bovine embryos in vitro produced with sex-sorted sperm

“…In cattle, approximately 5000 unsorted sperm [23] and as few as 600 [24] or 1500 to 2250 sexed sperm [4] are sufficient to fertilize a bovine oocyte in vitro, whereas 20 million unsorted sperm [25] and 1 to 4 million of sorted and frozen sperm [13,26] are normally used per AI. In vitro production (IVP) of embryos with sex-sorted sperm could justify the use of this sperm despite its higher price.…”

Reaction of fresh and frozen bull spermatozoa incubated with fresh and frozen bovine oviduct epithelial cells

“…This is consistent with the hypothesis that the AR sperm found up to 5 h of incubation represent sperm killed by freezing, and supports the commercial practice of using more total frozen-thawed sperm than fresh sperm for insemination. However, with 10 x 10 6 or 100 x 10 6 sperm inseminated Nadir et al [30] found no difference between fresh and frozen semen in accessory sperm attached per egg.…”

Sperm quality assessments for endangered razorback suckers Xyrauchen texanus

“…Accuracy in estimating sperm number is important in ART (Evenson et al 1993, Hansen et al 2002, in the standardization of cryopreservation methods , for studies of environmental chemical impacts to reproductive health (Haubruge et al 2000, Eustache et al 2001, as well as in predicting fertility (Nadir et al 1993) and post-thaw survival (Centola et al 1992). No single counting method is uniformly preferred in andrology or research laboratories.…”