There are three techniques for pregnancy diagnosis:
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Rectal palpation
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Ultrasonography
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Ballotment and mammogenesis i.e. development of mammary glands.
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Hormone (progesterone, estron sulphate)
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PAS
(pregnancy associated substances): early pregnancy factor (EPF),
pregnancy associated
glycoprot (PAG)
Clinical or Direct
Method
Rectal Palpation
Pregnancy Signs in Rectal Palpation:
-
Asymmetry
of uterine horn
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Position
of uterus
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Presence
of fetal membrane - allento-chorion (upto 30-90 days these are
detected), amniotic vesicle (as early as 35-40 days these are
detected), placentomes (formed by fusion of crunkles and
cotyledons. After 90 day detectable).
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Presence
of conceptus/fetus.
-
Presence
of CL on ovary
Estimation of stages of Pregnancy:
30 days:
35-40 days:
45 day:
60 day:
90 day:
-
Uterine horn 3 inches in diameter
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Placentome (1-1.5 cm) pea size
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Presence of CL
-
Chorioallontoic membrane
-
Fetus 6.5 inch (rat size)
120 day:
-
Uterus descending in pelvic brim
-
Placentome (1.5-2.5 cm)
-
Presence of CL
-
Chorioallontoic membrane
-
Fetus 10-12 inch (small cat size)
-
Presence of Fremitus (uterine artery)
150 day:
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Abdominal descending of uterus
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Palpation is difficult because fetus is in abdominal cavity
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Placentomes (2.5-4 cm)
-
Presence of CL
-
Fremitis (pulse feel in uterine artery)
-
Fetus is large cat sized
180 day:
210 day:
Ultrasonography
In this process real time B mode is used which detects the pregnancy
at day 26. It is also used to detect fetus heart beat, size, twin
pregnancy, fetal sex, and any abnormality etc.
Ballotment
In later stages of pregnancy fetus may be palpable through right
flank. Put pressure on the right side and feel fluid which is
positive sign of pregnancy.
Mammogenesis
Size of mammary glands increases. It is more pronounced in heifer
after 4-5 months.
Immunological Tests or
Indirect Method
Hormone Analysis
Progesterone:
Milk is preferred as sample. Serum is also used. Add sodium
dichromate in milk before sending it to lab. 21-24 days of pregnancy
is measured. 80 % accurate result for pregnancy. It is detected by
ELISA and RIA. If progesterone level is low, animal is in estrus. If
progesterone level is high, animal is in diestrus or pregnant.
Estronsulphate:
It is secreted from fetoplacental duct. RIA and ELISA are used to
detect estrosulphate. ELISA is more reliable. After 60 days it comes
to blood but its quantity is low. It can be detected after 80 days
in some cows but exact after 100 days. Level is at peak on 150 day.
Disadvantage is that it cannot be used for early detection.
PAS
(Pregnancy Associated Substances)
Early Pregnancy Factor:
It can be detected as early as 24-48 hours after fertilization. In
case of death of embryo it disappears from blood after 24-48 hours.
It is immunosuppressive agent so that fetus may not be
expelled. Rosette Inhibition Test is used to detect EPF. This is
laborious test so less used.
Pregnancy Associated Glycoprotein:
There are 21 glycoproteins and subdivided into 200. Important are
PAG A (from fetus, not secreted in blood, so cannot be detected),
PAG B (produced in placenta), PAG 60 (detected 28-30 days of
pregnancy). These are detected by RIA, ELISA. These help in
proliferation of the embryonic cells.
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