REPRODUCTIVE-PERFORMANCE OF DONORS AFTER FLUSHING AND OF RECIPIENTS WITH CONCEPTION FAILURES IN ET PROGRAM FOR PIGS

Fresh embryo transfer in pigs has not been a commonly used reproductio n biotechnology for the time being. The objective of the paper is to e valuate reproductive performance of embryo donors after surgical recov ery and of recipients that failed to conceive after laparoscopic embry o transfer. The problem of further reproductive performance is basical ly an important breeding factor for more frequent use of ET in pigs. T he effect of surgical recovery and unsuccessful laparoscopic transfer on further reproductive performance was studied on the basis of evalua tion of reproductive characteristics in the Ist and 2nd group of donor s that were described in the paper by Riha et al. (1997a) (one-to four -year sows of the Large White breed - LW, n = 16) and of recipients (n ulliparous gilts of the Czech expressly meat breed - CEM, rt = 16). Th e herd mates of both categories were used as control groups. The donor s involved sows of the same breed (LW) that farrowed in the same perio d (+/- 20 days) as the donors before they were used for stimulation an d embryo recovery (n = 14) while the recipients involved nulliparous g ilts of the same breed (GEM) included in breeding (in A.I.) in the per iod +/- 20 days from the date of insemination of recipients that faile d to conceive (n = 12). The interval from ET and/or from parturition t o A.I. in control animals was almost identical but the interval to con ception was insignificantly longer (77.90 +/- 37.21 days, 49.50 +/- 15 .31 days; P > 0.05). Conception rates after the Ist and 2nd inseminati on were significantly different (40% vs. 72%, P < 0.01; 40% vs. 21%, P < 0.05). No statistically significant differences were determined in pregnancy length nor in birth rates (P > 0.05 Tab. I). Tab. II shows a n overview of recipient use and piglet production after laparoscopic f resh embryo transfer. Further reproductive performance was evaluated i n nine gilts that failed to conceive and in 12 control ones. Four reci pients were excluded, and five conceived in 51.20 +/- 10.48 days after unsuccessful transfer, these data are statistically significantly hig her than in control gilts (51.20 +/- 10.48; 12.67 +/- 4.27 days; P < 0 .01, Tab. III). Conception and birth rates were almost identical in th e recipients that failed to conceive and in control gilts.