Some factors affecting the efficacy of oviduct tissue-conditioned medium for the culture of early bovine embryos

Abstract

Oviduct tissue-conditioned medium was evaluated for the culture of IVM-IFV bovine zygotes to the compact morula (cM) and blastocyst (BL) stages. Development was unaffected (P > 0.50) by freezing and thawing of conditioned medium: no. cM + BL/no. cleaved ova obtained after culture in nonfrozen, frozen-thawed, and control treatments were 31/148 (21%), 26/124 (21%) and 5/86 (6%), respectively. The greatest proportion of normal development was obtained after a conditioning period of 48 h (P < 0.05); no. of cM + BL/no. cleaved ova in media conditioned for 5, 24, 48 and 96 h were 23/114 (20%), 38/112 (34%), 43/115 (37%) and 36/125 (29%), respectively. Development declined with increasing dilutions of conditioned media (P < 0.005): no. cM + BL/no. cleaved ova for 100, 75, 50, 25 and 0% conditioned medium were 32/94 (34%), 29/94 (31%), 17/82 (21%), 10/94 (11%) and 11/73 (15%), respectively. The oestrous cycle stage from which oviductal tissue was obtained did not affect development (P > 0.75); no. cM + BL/no. cleaved ova was 21/63 (33%) at oestus and 21/79 (27%) in the luteal phase.