How to check pregnancy in Cows

Techniques for Pregnancy diagnosis in Cows

There are three techniques for pregnancy diagnosis:

 

Preganncy in cows

 

• Clinical or direct method

о  Rectal palpation

о  Ultrasonography

о  Ballotment and mammogenesis i.e. development of mammary glands.

•  Immunological tests or indirect method

о   Hormone (progesterone, estron sulphate)

о  PAS (pregnancy associated substances): early pregnancy factor (EPF), pregnancy associated
    glycoprot (PAG)

• Non return to estrus

Clinical or Direct Method

Rectal Palpation

Pregnancy Signs in Rectal Palpation:

•  Asymmetry of uterine horn
•  Position of uterus
•  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).
•  Presence of conceptus/fetus.
•  Presence of CL on ovary

Estimation of stages of Pregnancy:

30 days:

• Slight asymmetry of horn
• Presence of CL
• Chrio-allontoic membrane
• Amniotic vesicle pea size
• Uterus in pelvic cavity

35-40 days:

• Uterus in pelvic cavity
• Thinning of uterine wall
• Presence of CL
• Chrioallontoic membrane
• Amniotic vesicle size is yolk of hen (0.7 cm).

45 day:

• Uterus in pelvic cavity
• Thinning of uterine wall
• Presence of CL
• Chorioallantoic membrane
• Amniotic vesicle size small egg of hen

60 day:

• Uterus in pelvic cavity
• Presence of CL
• Chorioallontoic membrane
• Amniotic vesicle 9-10 cm
• Fetus size 2.5 inch
• Fetal membrane slip test is positives

90 day:

• Uterine horn 3 inches in diameter
• Placentome (1-1.5 cm) pea size
• 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:

• Abdominal descending of uterus
• Palpation is difficult because fetus is in abdominal cavity
• Placentomes (2.5-4 cm)
• Presence of CL
• Fremitis (pulse feel in uterine artery)
• Fetus is large cat sized

180 day:

• Abdominal descending of uterus
• Placentome (4-5 cm) equal to large coin
• Presence of CL
• Fremitus
• Fetus is small dog sized

210 day:

• Fetus easily felt due to increased size
• Placentome 
• Fremitus

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.