Pregnancy diagnosis in sheep and goats: a review

https://doi.org/10.1016/0921-4488(95)00644-ZGet rights and content

Abstract

During the last two decades, attempts have been made to diagnose pregnancy in sheep and goats by ultrasonic means. Between 60 and 80 days of gestation, an A-scan instrument is approximately 95% accurate and Doppler system is up to 100% accurate in diagnosing pregnancy greater than 60 days post-breeding. With real time B-scan ultrasound, pregnancy can be detected as early as 25 days of gestation. Fetal viability, fetal numbers and also the diagnosis of some reproductive tract disorders are possible. Determination of estrone sulfate assay provides a highly sensitive and specific pregnancy test for ewes and does 70 and 50 days post-breeding, respectively. Determination of progesterone on Day 20 of the gestation provides 90% accuracy in ewes and does but is not specific for pregnancy. Pregnancy diagnosis and fetal counts are possible using radiography 90 and 70 days of postbreeding in ewes and does, respectively, but is not feasible in the field. Rectal abdominal palpation is relatively inexpensive and easy to perform in the field in sheep with an accuracy of 90% at 60 days of gestation. It is unsuitable for goats cause of the risk of trauma, abortion or death. By Day 40 of gestation, an accuracy of 97% has been obtained using vaginal biopsies, but it requires laboratory facilities. Direct palpation of the pregnant uterus via laparotomy after Day 28 and Day 42 of gestation in ewes and does provides 92–100% accuracy, but has also limited field application. Abdominal palpation and ballotment are only effective during late pregnancy and do not give always reliable information. Pregnancy-specific antigen chorionic somatomotrophin in serum of ewes results in 97% accuracy 55 days post-breeding. Older techniques such as palpation of the cervix, mammary secretion and increase in body weight (BW) have been replaced.

References (59)

  • M. Shelton

    Reproduction and breeding of goats

    J.Dairy Sci.

    (1978)
  • C. Tamanini et al.

    Esterone and esterone conjugate plasma level through out pregnancy in the goat; their determination as a pregnancy diagnosis test

    Anim. Reprod. Sci.

    (1986)
  • C.P.W. Tsang

    Plasma levels of esterone sulfate, free estrogens and progesterone in the pregnant ewe throughout gestation

    Theriogenology

    (1978)
  • A.I. Worsfold et al.

    Measurement of esterone sulphate in sheep plasma as a possible indicator of pregnancy and the number of viable fetuses present

    Br. Vet. J.

    (1986)
  • C.A.V. Barker et al.

    Radiographic detection of fetal numbers in goats

    Can. Vet. J.

    (1967)
  • K.N. Bretzlaff et al.

    Use of an enzyme immunoassay to determine concentrations of progesterone in caprine plasma and milk

    J. Am. Vet. Med. Assoc.

    (1989)
  • K.N. Bretzlaff et al.

    Ultra-sonographic determination of pregnancy in small ruminants

    Vet. Med.

    (1993)
  • B.C. Buckrell

    Applications of ultrasonography in reproduction in sheep and goats

    Theriogenology

    (1988)
  • D.A. Callagan et al.

    Ultrasonic Doppler observation of the fetal heart

    Obstet. Gynecol.

    (1964)
  • C.G. Davey

    An evaluation of pregnancy testing in sheep using a real-time ultrasound scanner

    Aust. Vet. J.

    (1986)
  • M. Dobeli et al.

    Pregnancy diagnosis in sheep by repeated progesterone assay in blood plasma

    Zuchthy

    (1985)
  • A. Domanski et al.

    Increase in body weight as a method for diagnosing pregnancy in ewes

    Rocz. Nauk. Roln. Ser.

    (1966)
  • E.J.H. Ford et al.

    The detection of fetal numbers in sheep by means of X-rays

    Vet. Rec.

    (1963)
  • A.F. Fraser et al.

    The detection of foetal life in ewes and sows

    Vet. Rec.

    (1967)
  • R.J. Holdsworth et al.

    Measurement of progesterone in goat milk: an early pregnancy test

    Vet. Rec.

    (1979)
  • C.V. Hulet

    A rapid abdominal technique for diagnosing pregnancy in the ewe

    J. Anim. Sci.

    (1972)
  • C.V. Hulet et al.

    A rapid technique for observing the reproductive tract of living ewes

    J. Anim. Sci.

    (1968)
  • G.C. Jain et al.

    Milk progesterone content and pregnancy diagnosis in goats

    Zbl. Vet. Med. A.

    (1980)
  • M.G. Keane

    Pregnancy diagnosis in the sheep by a ultrasonic method

    Irish Vet. J.

    (1969)
  • Cited by (59)

    • Accuracy of assessment of luteal morphology and luteal blood flow for prediction of early pregnancy in goats

      2018, Theriogenology
      Citation Excerpt :

      Such findings enable an intensification of breeding programs, as non-pregnant does can be resubmitted to a second AI protocol after a shorter period when compared to a classical US pregnancy diagnosis (on Day 30 post-breeding). Moreover, the proposed methodology may be a very useful alternative for reproductive management during non-breeding season, as pregnancy diagnosis based on signs of estrus return cannot be reliably performed [27]. The earliest pregnancy diagnosis can also be adopted in resynchronization programs, in order to avoid a new ovulation and/or the necessity of additional hormones in the protocol, such as PGF2α, which could result in a loss of an undetected pregnancy.

    • Evaluation of the Nova Vet Meter for sheep-side monitoring of β-hydroxybutyric acid (BHBA) and description of ewe BHBA during late gestation in three flocks from the Northeastern U.S.

      2018, Research in Veterinary Science
      Citation Excerpt :

      Tools are available to producers to improve the gestational management of flocks. By integrating ultrasound during early gestation, producers can estimate offspring gestational age and forward calculate parturition dates (Ishwar, 1995; Jones et al., 2016; Jones and Reed, 2017). Producers may also determine the number of fetuses each ewe is carrying (Jones et al., 2016; Jones and Reed, 2017).

    • Early pregnancy diagnosis in ewes by subjective assessment of luteal vascularisation using colour Doppler ultrasonography

      2018, Theriogenology
      Citation Excerpt :

      In both studies, pregnancy was determined with high accuracy in ewes as early as 17 days after oestrus, which may allow development of strategies for more intense reproductive management, such as early re-synchronisation of oestrus in non-pregnant ewes, saving almost 2 weeks compared with early pregnancy diagnosis done by transrectal classical ultrasound [23]. In addition, colour Doppler US may be very useful for reproductive management for out-of-season breeding, as pregnancy diagnosis based on the return of oestrus signs cannot be reliably performed [24]. Therefore, colour Doppler US in sheep is useful not only for health diagnoses [25], but also has a direct positive impact on productive and reproductive management decisions.

    • Ultrasonographic examination of the uterus of ewes during the post-partum period

      2017, Small Ruminant Research
      Citation Excerpt :

      Regeneration of the superficial layer of the endometrium is considered to be complete by the 28th day post-partum. Various techniques have been proposed for the study of uterine involution in ewes, e.g., hormone measurement (Ishwar, 1995; Degefa, 2003), radiographic imaging (Tian and Noakes, 1991; Goddard, 1995), laparoscopic investigation (Ishwar, 1995) or post-mortem examination (Rubianes and Ungerfeld, 1993; Ababneh and Degefa, 2005; Degefa et al., 2006). Some of the disadvantages of the above techniques include invasiveness, reduced accuracy, difficulty to apply in clinical conditions and need to sacrifice the experimental animals.

    View all citing articles on Scopus
    View full text