METHODS OF PREGNANCY DIAGNOSIS IN SOWS

Pashu Sandesh, 09 July 2022

Madhu Shivhare, Madhuri Dhurvey, Kavita Rawat, Jyotsana Shakkarpude, Deepika Ceaser and Akansha Singh

Assistant Professor 

Department of Veterinary Gynaecology and Obstetrics 

College of Veterinary Science and AH, Mhow (M.P.)  

Different methods have been used to detect pregnancy in the sow. They are as follows:

• Management Methods
• Clinical Method – Trans-rectal Palpation
• Ultrasonographic Methods
• Laboratory Methods
• Vaginal biopsy
• Plasma progesterone assay
• Plasma estrogen assay

• MANAGEMENT METHOD

• Failure to return to estrus at 18-22 days after service or artificial insemination is considered pregnant.
• This may also be due to a reluctance to show signs, anestrus or ovarian cysts.
• Early identification of pregnant sow or gilt is essential so that breeders can certify before the sale, that she can be served again, treated or culled.

• LABORATORY METHODS - Laboratory methods include

• Vaginal Biopsy
• Plasma Progesterone Assay
• Plasma Estrogen Assay

• VAGINAL BIOPSY - Histological assessment of the number of layers of the stratified squamous epithelium of the vaginal mucosa obtained by biopsy can be used as a method of diagnosing pregnancy.

• Between 30-90 days of pregnancy, the accuracy is over 90%.
• Sections taken erroneously from the cervix or posterior vagina are unsatisfactory for diagnosis.
• Although the technique is a satisfactory one, the big disadvantage is the cost of the procedure and the time taken to perform the test.

• PLASMA PROGESTERONE ASSAY

• In non-pregnant cyclical animals, from about day 16, there is a decline in progesterone concentrations in the peripheral blood.
• Estimation of progesterone concentrations from this time after-service would be useful.
• Accuracy at 16-24 days after service: 96%
• Plasma values ≥ 7.5ng/ml are indicative of pregnancy.
• More reliable to identify non-pregnant sows because of the irregularity of the inter-estrus interval.
• The major problem is difficulty in obtaining blood samples.

• PLASMA ESTROGEN ASSAY

• In pregnant animals, estrogens are detectable from day 20 of gestation.
• A small volume of blood sufficient for the assay can be collected from the ear vein.
• The optimum time to perform the assay is about 24—28 days.