Bovine epididymal spermatozoa treatment for in vitro fertilization: Heparin accelerates fertilization and enables a reduction in coincubation time

Abstract

This study aimed to establish a protocol for in vitro embryo production using epididymal sperm (EP). Samples were obtained from ejaculated sperm (EJ) and the epididymis of 7 Gir bulls. First, the effect of heparin (+) on the viability, longevity (Experiment 1) and fertilization rates (Experiment 2) of the EP was evaluated. In experiment 2, a pool of EP and EJ sperm (n = 7) was coincubated with cumulus-oocyte complexes (COCs) for 0, 3, 6, 12 and 18 h, and the fertilization rate (FR) was evaluated. A third experiment was performed to test sperm treatments for IVP using the Percoll (P) or PureSperm (PS) gradients or a spTALP wash for sperm selection. Cleavage, blastocyst rate (BR) and embryo sex were evaluated. In experiment 4, embryos were produced using 6, 12, and 18 h of sperm-oocyte coincubation. The cleavage, BR, and total number and percentage of apoptotic cells were determined. Heparin affected EP viability, longevity and FR. After 6 h, 82% of the oocytes were fertilized in the EP+ group, a higher value (P<0.05) than that in the EJ (19%) and EP- (42%) groups. At 12 and 18 h, FR remained higher in the EP+ group, and a gradual increase in polyspermy was observed. The use of a P or PS gradient yielded a similar BR on D7 (54% and 52%), which was higher than the rate obtained using the washing method (37%). The embryos produced by EP and selected in a P or PS gradient resulted in a sex deviation in favor of male embryos (P>0.05). No differences (P>0.05) were observed among the groups that were coincubated for 6, 12 and 18 h with respect to embryo production, kinetics of development, total cell number and percentage of apoptotic cells. In conclusion, IVF time can be reduced to 6 h without affecting embryo production and quality. In addition, EP sperm selection can be performed by either a PS or P gradient.

The Quality and Fertilizing Potential of Red Deer (Cervus elaphus L.) Epididymal Spermatozoa Stored in a Liquid State

“…Previous studies have shown that despite certain differences in the characteristics of epididymal spermatozoa and freshly ejaculated sperm, the former can be effectively used for in vitro fertilization (IVF) and artificial insemination (AI) of farm animals, including pigs [ 4 ], bulls [ 5 ] and stallions [ 6 ].…”

Different Methods for Seminal Plasma Removal and Sperm Selection on the Quality and Fertility of Collared Peccary Sperm

“…62.3%), cleavage (43.5% vs. 26.6%), and blastocyst (18.1% vs. 10.5%) compared to WC [ 54 ]. In cattle, a better blastocyst rate was also observed (56% vs. 38%) after sperm separation with PG compared to after washing [ 55 ]. Obtaining blastocyst-stage embryos after heterologous IVF of collared peccary sperm and pig oocytes was not feasible, likely due to the species differences and the variations in culture conditions.…”

Assessment of the Quality of Frozen-Thawed Semen or Epididymal Sperm in Three Native Vietnamese Pig Breeds

“…After removing the testicle, the sperm is kept in the tail of the testicle, and the sperm is exposed to a fluid at the time of ejaculation [26]. These fluids contain several substances that are an important influence on sperm viability and motility in the female reproductive tract, such as ions, lipids, energy substrates, organic compounds and proteins [32].…”