Addition of penicillamine, hypotaurine and epinephrine (PHE) or bovine oviductal epithelial cells (BOEC) alone or in combination to bovine in vitro fertilization medium increases the subsequent embryo cleavage rate

Abstract

The cleavage rate of in vitro-matured bovine oocytes was compared after fertilization in 1) TALP medium alone (control); 2) in TALP + BOEC; 3) in TALP + PHE; or 4) in TALP + BOEC and PHE. The overall cleavage rate at 45 h post insemination was greater for embryos in Treatments 2 (52%), 3 (55%) and 4 (66%) than for Treatment 1 (32%). The oocyte cleavage rates for Treatments 2 and 3 were similar, but were lower than that of Treatment 4. Addition of PHE or BOEC, alone or in combination, to the fertilization medium resulted in more embryos at the 3- or 4-cell stage than the 2-cell stage by 45 h post insemination. After 5 d of co-culture with BOEC in M-199 medium, 21, 28, 25 and 35% of the cleaved embryos in Treatments 1, 2, 3 and 4, respectively, developed to the morula or blastocyst stage. The rate of development to morulae and blastocysts was similar among Treatments 1, 2 and 3, and between Treatments 2 and 4. Across treatments, a correlation of 0.98 was noted between the portion of embryos that had reached the 3- or 4-cell stage by 45 h post insemination and the percentage of embryos in each treatment that continued to develop to the morula or blastocyst stage in vitro.