OVIDUCTAL FLUID AND GROWTH-FACTORS FAILED TO ENHANCE DEVELOPMENT OF PORCINE EMBRYOS

Porcine embryos (1-, 2- and 4-cell) were cultured in a basal medium co nsisting of Krebs-Ringer bicarbonate buffer supplemented with oviducta l fluid and several growth factors and observed for further developmen t. Oviducts were flushed at either 48 h (Experiment 1) or 96 h (Experi ment 2) after the onset of estrus. Observations were made every 48 b ( Experiment 1) or 12 h (Experiment 2) until failure of the embryos to d evelop for 2 consecutive observations. Embryos were scored 0 = no deve lopment, 1 = cleavage, 2 = morula, 3 = blastocyst, or 4 = hatched blas tocyst. In the first experiment, development of 1-, 2- and 4-cell embr yos (n = 282) in the basal medium supplemented with oviductal fluid (4 :1) or 3 sets of growth factors, was less or equal to one cleavage sta ge. Those embryos cultured in the basal medium supplemented with bovin e serum albumin (fatty acid free) (BSA) advanced to the blastocyst sta ge. In the second experiment, 96 h aged embryos (n = 142) were culture d in the basal medium supplemented with IGF-1 and - 2 and EGF, or with BSA alone or with BSA and the three growth factors. In the treatments without BSA, the embryonic development was less than one cleavage, wh ereas in those treatments with BSA, embryos advanced beyond hatching a nd began to expand. We conclude that for culture of porcine embryos, s upplementation with several growth factors or with oviductal fluid, in the concentration used in this study, was of little benefit at this s tage of development. However, the type of BSA significantly affected d evelopment. More than 90% of the embryos reached the morula and blasto cyst stages in medium than included BSA (fatty acid free).