In Exp. 1 pig oocytes matured in vitro were used to evaluate the fertilizability in vitro of frozen epididymal (4 boars) and ejaculated (3 boars) spermatozoa that were preincubated in modified TCM-199 for 4 h at 37 degrees C. The percentages of penetrated oocytes with the frozen epididymal spermatozoa were 0-40%. In contrast, none of the oocytes were penetrated with the frozen ejaculated spermatozoa. In Exp. 2, oocytes matured in vivo were inseminated in vitro with the frozen epididymal spermatozoa that were known to penetrate oocytes matured in vitro. The penetration rate was 79% and the percentage of polyspermic oocytes was 57%. Culture for 30 h of oocytes matured in vivo and fertilized in vitro resulted in 51% (34/67) developing to the 2-cell stage. These embryos were transferred to 2 recipient gilts. One gilt became pregnant and a litter of 3 (1 live and 2 dead) was born. These results indicate that frozen epididymal spermatozoa can be used for in-vitro fertilization in the pig.

No abstract

No abstract

No abstract

The incidence of chromosomal anomalies in early bovine embryos derived from follicular oocytes fertilized in vitro using sperm separated by Percoll density gradient centrifugation was investigated. Overall, chromosomal anomalies were observed in 13.7% (138/1005) of embryos. There were 14 haploids (1.4%), 2 hypodiploids (0.2%), 6 hyperdiploids (0.6%), 101 triploids (10.0%), 12 tetraploids (1.2%), 2 diploid/triploid mosaics (0.2%), and 1 diploid/tetraploid mosaic (0.1%). The frequency of triploidy was caused mainly by polyspermy. There was a significant difference in the frequency of embryos with abnormal chromosomes between the two bulls used (P less than 0.005), but Percoll centrifugation did not affect the observed incidence of anomalies. The frequency of chromosomal anomalies in embryos at each stage increased with delay or arrest of development. These results suggest that the incidence of chromosomal anomalies depended on the conditions of in vitro fertilization and the arrest of development.