Efeito da flunixina meglumina, somatotropina recombinante bovina e sincronização de receptoras sobre a taxa de prenhez de embriões bovinos produzidos in vitro

Abstract

The variability of successful transfers of embryos produced in vitro is still one of the obstacle to its expansion, where some of the problems are related to early embryonic mortality. The aim of this work was to evaluate the application of flunixin meglumine and recombinant bovine somatotropin and observe the effect of variables such as embryonic development, embryo synchrony with the recipient, corpus luteum size at the time of transfer and pregnancy rate. In the first experiment 55 recipient heifers were randomly in the three different groups: G1 control group (n=15 animals); G2 group receiving 500mg of recombinant bovine somatotropin (bST)/animal/subcutaneous (n=20 animals) and G3 group receiving 500mg flunixin meglumine/animal/intramuscular (n=20 animals). Pregnancy rates for G1 53,33% (8/15), G2 60% (12/20), G3 55% (11/20) with no statistically significant difference between groups (P> 0,05). In experiment II 134 heifers were used as recipients of embryos produced in vitro. The pregnancy rate was evaluated according to the degree of development of the structure transferred embryo synchrony with the receiver, and corpus luteum size. Embryos (blastocyst, expanded blastocyst, ecloded blastocyst) showed better pregnancy rates than less development younger embryos (morula, early blastocyst), 57,14% and 25% respectively (P<0,05). Synchrony with the recipient embryo -1 (68,42%), 0 (88,88%), +1 (41,5%) for P<0,05 and size of the corpus luteum large 46,83% CL1, CL2 average 55,88%, 42,85% CL3 small (P> 0,05). In conclusion, under experiment conditions described, the application of flunixin meglumine, recombinant bovine somatotropin and was not efficient to increase the pregnancy rate, but it is note that the pregnancy rate varied in the degree of development of the embryo and the embryo synchrony with the recipient.