[Suitability of sonographic evaluation of ovarian dynamics and uterine involution for prediction of postpartum fertility in the cow].

To investigate the suitability of sonography for prediction of puerperal fertility, we used 34 cows with normal puerperium. For this purpose, the animals were examined gynecologically and by transrectal sonography at 10-day intervals between day 15 and day 45 p.p. as well as at oestrus, when they were inseminated. We judged uterine involution by diameter and sonographic structure of the uterine cross-section and ovarian activity by the presence of follicles and corpora lutea. Cows, which became pregnant after first insemination p.p., were assigned to group G1 (n = 16) and animals, which failed to conceive, to group G2 (n = 18). The cows of G1 obtained significantly better results concerning both uterine involution and ovarian activity than cows of G2. Thus, diameter of the uterine horn decreased faster and sonographic structure of the uterine cross section returned markedly earlier to the nonpregnant appearance in G1 than in G2. Group G1 also showed a significantly higher percentage of dominant follicles at all examinations. The results of the study show a distinct relationship between uterine involution and ovarian activity and puerperal fertility. But it has also to be resumed that the prediction of fertility for individuals will always be restricted by other reasons causing failure of conception.