Ultrasonic control of early pregnancies, embryonic and fetal mortalities and fetal sex in zebu cattle

Abstract

This study analysed the efficiency of early pregnancy diagnosis and embryo and fetal mortality and sexing evaluation by ultrasound in two groups of zebu cows submitted to artificial insemination (G1) or embryo transfer (G2 = G2A and G2B). The animals that not returned to estrus at 21th day after artificial insemination (G1) and 14th day after embryo transfer (G2B) were examinated at 25th day of gestation for early pregnancy diagnosis, at 45th day for embryo mortality between 25th and 45th and at 60th days for fetal mortality between 45th and 60th days and sexing evaluation. The animals from group G2A were examinated by retal palpation at 45th day for gestation diagnosis and at 60th day for fetal mortality between 45th and 60th days and sexing evaluation. The pregnancy rates were 94.6%, 88.1% and 83.4%, respectively, to 25, 45 and 60 days of pregnancy. The embryo and fetal mortality and abortion rates were, respectively, 4.6%, 4.7% and 1.2%. The accurate early pregnancy diagnosis and fetal sexing were, respectively, 88.5% and 90.7%. The ultrasound was efficient to evaluate early pregnancy (25th day), embryo mortality (25th to 45th days), fetal mortality (45th to 60th days) and sexing (60th day). The detection of early pregnancy can be applied to establish the stages of highest embryo and fetal mortality rates in zebu cattle. This study revealed that embryo and fetal mortality rates in Bos indicus were not caused by ultrasound examination.