TRANSCERVICAL EMBRYO COLLECTION AND REPRODUCTIVE-PERFORMANCE OF SOWS WITH RESECTIONED UTERI

Three experiments were performed. In Exp. 1 the reproductive performance of sows with resectioned uteri and the embryonic recovery after repeated transcervical collection and after slaughter was determined. In Exp. 2 the embryonic development in sows with resectioned uteri was compared with the embryonic development in intact sows. In Exp. 3 the embryonic recovery (after transcervical collection) and development were studied in three consecutive oestrous cycles with superovulation induction in Cycle 2. After uterine resectioning in 16 sows, three sows were culled, two due to endometritis and one due to repeated cervical passage problems. The 13 other modified sows remained cyclic and eggs/embryos could be recovered repeatedty by transcervical flushing on Day 5 or 6 after insemination. In Exp, 1 the length of the oestrous cycle of six modified sows increased from 20.2 +/- 1.2 to 21.2 +/- 1.3 (n = 18; p < .05) after transcervical embryo collection. Transcervical recovery was 6.2 +/- 4.2 eggs/embryos per collection (n = 11). After slaughter the average number of recovered eggs/embryos was 12.0 +/- 6.0 (n = 6). No major adhesions or other disturbances of the genital tract were detected after slaughter and the number of CL was normal (19.7 +/-2.5). In Exp. 2 the transcervical recovery was 6.3 +/- 3.4 (n = 7) eggs/embryos. An average of 85.0 +/- 19.1% (n = 4) and 80.5 +/- 39.6% (n = 6) morula and blastocysts were collected from modified saws and intact control sows, respectively (p > .05). The embryonic cell cycles were on average 4.0 +/- 0.9 (n = 4) and 4.2 +/- 1.5 (n = 6) per sow for modified sows and intact control sows, respectively (p > .05). In Exp. 3 the transcervical recovery was 8.1 +/- 5.5, 18.4 +/- 25.0 and 8.0 +/- 6.3 eggs/embryos in Cycle 1, 2 (superovulated) and 3, respectively (p > .05). The percentage retarded embryos (2-8 cells) was 6.7 +/-14.9, 24.7 +/-20.2 and 1.9 +/- 3.2 (p < .05) and the percentage morulae and blastocysts was 89.0 +/- 13.7, 59.7 +/- 26.3 and 89.8 +/- 13.1 (p > .05) in Cycle 1, 2 and 3, respectively. The average embryonic cell cycles were 4.4 +/- 0.7, 3.3 +/- 0.6 and 3.5 +/- 0.4 in Cycle 1, 2 and 3, respectively (p < .01). It is concluded that repeated transcervical embryo collection is possible in sows with resectioned uteri, without causing major reproductive disorders. Superovulation can increase the recovery, but the results are very variable.