Submission Number: PAR-4-99-134

Abstract Number: 556

MEASUREMENT OF DIFFERENT PARTS IN CHALL FETUSES TO DETERMINE PREGNANCY AGE.

P Tajik* ¹, A Veshkini ² and S Soroori ²

Division of Theriogenology, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran ¹
Surgery and Radiology, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran ²

Abstract:
Determination of the fetus age is of great importance in breeding programs. Among the sheep breeders in Iran, Chall has been famous for gaining weight as well as breeding 2-3 lambs a year. Our study was conducted to measure some parts of the Chall fetus such as biparietal distance (BPD), radius, and tibia length to give a standard for future determination of the fetal age and/or teratology in this breed. Estrus in sixteen Iranian Chall ewes was synchronized by 2 injections of PGF₂ (12.5 mg Lutalize, Upjohn Co.) 8 days apart. Forty-eight h after the 2nd injection, ewes were randomly divided into 2 groups and each was introduced to a fertile ram for 24 h (day ram was introduced was counted as day 0). Early pregnancy diagnosis was performed via transrectal (with or without abdominal pressure) and transabdominal ultrasonography in the standing position (because it seems to be more quickly accomplished than the other positions such as dorsal recumbency). When the transrectal method could no longer be used, it was substituted by transabdominal. Ultrasonography was performed until day 130. At day 20 post breeding, 56% showed pregnancy. By day 25, pregnancies were diagnosed in all ewes. Diagnostic value of transrectal ultrasonography was high in early pregnancy. However, in 56%, 78% and 100% of the cases, abdominal pressure was obligatory to assess the pregnancy from day 23, 25, and 30, respectively. Day 82 was the last time that transrectal ultrasonography could be used in 22% of the cases, and all required abdominal pressure. In 22% of the cases, transabdominal ultrasonography could diagnose the pregnancy in day 20. In days 23, 25, and 30, this value was 44%, 78% and 100%, respectively. Amniotic vesicle was 8.1 mm in diameter in day 20; and it was 12, 19.4, 24.5 and 29 mm in days 23, 25, 30 and 33 of pregnancy. The first assessment of BPD was day 37, and it was 10.6 mm. BPD was 12.5, 13.6, 16.6, and 19 for days 40, 47, 54, and 61 of pregnancy. Radius was 7.8, 11.5, 16, 26.6, 37.3, 55 and 72.9 mm in days 54, 61, 68 82, 102, 117 and 130. Tibia length was 8.3, 12.4, 17.1, 23.3, 19.1, 44.9, 71.3 and 90 mm in the same days.

Keywords: N/A

This abstract is being presented at: 8:00 AM in session:
Pregnancy and Parturition II