Rectal damage in ewes following pregnancy diagnosis by rectal-abdominal palpation

Lack of effect of transrectal ultrasonography with restraint on lambing rate and prolificacy in ewes

The objective was to determine if transrectal ultrasonography for determination of pregnancy in restrained ewes increases embryonic/fetal death or loss of pregnancy. Ten flocks (N=873 ewes) bred in either the estrous or anestrous season were randomized, into control (C) or examined (E) groups within flock. Examined ewes were placed in a tilting squeeze chute and scanned by one of three operators for pregnancy by transrectal ultrasonography once between Days 25 and 100 post-breeding. Control ewes were not subjected to handling in the squeeze chute or pregnancy diagnosis. Two operators counted embryos in E ewes in six flocks. There were no differences between E and C ewes in percent ewes lambing or lambing rate on a per flock basis. Prolificacy per flock was greater in E ewes (P=0.05; 1.53 versus 1.60, C and E, respectively) than in C ewes. Eighty-five percent of exposed ewes lambed in the estrous season, while only 62% of ewes lambed in the anestrous season (P=0.05). Overall prolificacy did not differ with season (1.60 versus 1.53), and there was no season by treatment interaction for any variable tested. Losses averaged 0.02 per E ewe exposed in the estrous season and 0.20 in the anestrous season (P<0.05). Examined ewes in this study had similar pregnancy and lambing rates to C ewes in the same flocks and prolificacy was slightly greater. Based on these data, the combination of transrectal ultrasonography with restraint is safe for pregnancy diagnosis in ewes.

Comparison of accuracy of transabdominal ultrasonography, progesterone and pregnancy-associated glycoproteins tests for discrimination between single and multiple pregnancy in sheep

The aim of the present study was to evaluate and, compare the accuracy of transabdominal ultrasonographic (US) and the progesterone (P4-RIA) and ovine pregnancy-associated glycoprotein (ovPAG-RIA) tests for the discrimination between single and multiple pregnancy in sheep. One hundred pregnant AwassixMerino ewes were scanned by transabdominal ultrasonography (3.5 MHz linear-array transducer) at Days 43-56 and 81 of these ewes were scanned at Days 76-87 of gestation. The ewes were scanned in dorsal recumbency at the bare area of the inguinal regions (without pre-scanning shaving of the ventral abdominal wall). After each scan, blood samples were withdrawn from the jugular vein to estimate the levels of P4 and ovPAG by radioimmunoassay. At lambing, 61 ewes gave birth to single lambs and 39 ewes gave birth to multiples. The sensitivity of the transabdominal US, the P4-RIA and the ovPAG-RIA tests for determining ewes carrying multiples was 54, 64.1 and 64.1% at Days 43-56. At Days 76-87 of gestation these accuracies were 60.0, 66.7 and 76.6% for the US, P4-RIA and PAG-RIA tests, respectively. The specificity of the transabdominal US, the P4-RIA and the ovPAG-RIA tests for determining ewes carrying singles, was 78.6, 60.7 and 62.3% at Days 43-56 and 78.4, 64.7 and 70.6% at Days 76-87 of gestation, respectively. It is concluded that the accuracy of transabdominal ultrasonographic (without pre-scanning shaving of the ventral abdominal wall), the P4- and the ovPAG-RIA tests for determination of the fetal numbers in AwassixMerino crossbred ewes is too low to be used in the field.

Gynecological examination and pregnancy diagnosis in small ruminants using bimanual palpation technique: a review

A palpation technique using both hands was developed by the author and used for examination of internal reproductive organs, pregnancy diagnosis, and assessment of approximate stages of gestation in small ruminants. The study was conducted in 4 stages on 87 female goats and 30 slaughterhouse source ewes First, 20 doelings and 15 does with no recent history of insemination were examined by two hand method for palpability and structural integrity of internal reproductive organs. Next 52 goats (28 doelings and 24 does) were examined at 28 to 30 d post insemination for pregnancy. Among those diagnosed pregnant, 20 goats were examined at 15 d intervals to assess the palpable changes of pregnancy. Preslaughter palpation followed by post-slaughter verification of the findings were performed in 30 ewes. The two hand method was effective for palpating the reproductive tract in the nonpregnant goats irrespective of parity status. Gross palpation of the ovaries was possible in 83% of the goats. Of the 52 goats examined for pregnancy at 28 to 30 d, 29 (56%) had clear distension of uterus while 23 (44%) did not. The results were confirmed by kidding date or returning to service. Changes of the reproductive tract were monitored in 20 goats at biweekly intervals and the findings categorized by the stage of gestation. Post slaughter verification of preslaughter findings based on two handed palpation indicates that this technique can be used for early pregnancy diagnosis and assessment of the stage of gestation in goats and ewes.

Ultrasonography of the uterus of the goat

The use of a transabdominal or a transrectal scanning technique to visualize the uterus in goats is discussed. The results of sonographic imaging of normal (non-pregnant, pregnant, postpartum) and abnormal (endometritis, hydrometra, fetal death) uterine structures are reviewed. In the goat, special attention must be paid to distinguishing between the sonographic image of hydrometra and early pregnancy. A case of hydrometra that developed in the presence of three dead fetuses is reported. It is concluded that, under field conditions, transabdominal scanning of goats, performed between days 40 and 70 after mating, yields information about pregnancy, fetal viability, and single or multiple pregnancy, while at the same time making possible a reliable differential diagnosis of pregnancy and hydrometra.

Ultrasonic biparietal diameter of second trimester Pygmy goat fetuses

Four does pregnant with seven Pygmy goat fetuses were scanned transabdominally from Day 36 to Day 102 of gestation using a real-time ultrasound 5 MHz linear-array scanhead. Fetal biparietal diameter (BPD) was measured on symmetrical frozen images using internal electronic calipers. The relationship between gestational age (GA) in days and BPD in millimeters in Pygmy goat fetuses is expressed as: [GA = 23.2 + 2.08 BPD]. This equation can assign GA to Pygmy goat fetuses of unknown conception dates and allow confinement of does near kidding for induced or observed parturition. Mean kid birthweight was 2.0 + 0.45 kg SEM. These observations are consistent with relationships which have been determined for Toggenburg, Nubian and Angora goat fetuses.

Use of ultrasonography in reproductive management of sheep and goat herds

Real-time ultrasound evaluation of small ruminants offers an unparalleled range of information regarding pregnancy status, number of fetuses, and gestational age. The advantages of real-time ultrasonography are its sensitivity and accuracy of various diagnoses, its speed, and its safety. Overall flock reproductive management is facilitated through the timely acquisition of information with ewes culled, rebred, or preferentially fed, according to pregnancy status. Breeding dates of pasture-bred does can be assigned with sufficient accuracy to allow parturition induction at term without risk of severe immaturity in kids. Diagnoses other than pregnancy, such as pyometra, nydrometra, fetal resorption, and fetal mummification also can be made using real-time ultrasonography.

Improved diagnostic accuracy by repetitive ultrasonic pregnancy testing in sheep

Operator effects and instrument accuracy in using the Scanopreg ultrasonic pregnancy detector in sheep bred at synchronized estrus were studied in three experiments. In the first study, four operators tested the same 101 ewes at 60 and 80 days after breeding. The only significant difference among the four operators was that one operator consistently underestimated pregnancy. Operators did not differ in their diagnoses between days 60 and 80. In the second study, there were no differences between two operators who tested 239 ewes 90 days after breeding. In the third study, one operator tested 318 ewes 60, 70 and 90 days after breeding. The accuracy of diagnosis of pregnancy was at least 90% on each day tested; the corresponding diagnoses of nonpregnancy were 52, 76 and 79% correct. Some ewes that were initially diagnosed as nonpregnant were correctly recognized as pregnant when tested later than day 60. Most of the missed pregnancies were in ewes carrying a single lamb. A second Scanopreg test on day 90 of ewes not diagnosed pregnant on day 60 or 70 identified additional ewes as pregnant. Paired tests (days 70 and 90) recognized 99% of the ewes that eventually lambed.