Pregnancy Diagnosis

Question 1

What are the four ways to diagnose pregnancy?

Answer 1

Non-return to oestrus - Hormone measurement - Detection of gravid uterus - Change of gross and microscopic structure of genital system

Question 2

What are the three ways to detect a gravid uterus?

Answer 2

Manual palpation - Ultrasonography - Radiography

Question 3

From day 13 what does an embryo produce? What is the point of this?

Answer 3

Interferon Tau (bIFN-t) - prevent luteolysis of the CL

Question 4

From what time can Ultrasonography be used for PD?

Answer 4

after 30 days

Question 5

When doing PD of a cow by rectal examination, what are the major landmarks for PD and when?

Answer 5

Palpation of chorioallantois (33 days) - Disparity in horn size (35 days) - Palpation of foetus (45-60 days) - Presence of placentomes (80 days) - Oestrone Sulphate in milk (120 days) - Palpation of foetus (120 days)

Question 6

If doing a PD by progesterone analysis, after which day should the assay be done? Why?

Answer 6

21 days (day 24) - Normally when luteolysis happens if not pregnant so progesterone would drop if -ve PD

Question 7

When doing a progesterone analysis, where should the sample be taken? Which is better and why?

Answer 7

Milk or plasma - Milk as progesterone is in higher concentrations

Question 8

What is progesterone analysis a test for? How accurate is it?

Answer 8

Test for NON- pregnancy - 99%

Question 9

Why should progesterone analysis not be used for positive PD?

Answer 9

There are other things that can cause higher progesterone levels than normal which would lead to false positives

Question 10

Give examples of how disparity of horn sizes can give false PD positives

Answer 10

Incomplete involution - Fluid in horns -> pus (pyometria), mucous (mucometria), watery secretion (hydrometria)

Question 11

Explain how Oestrone sulphate give a +ve PD?

Answer 11

Oestrone produced by feto-placental unit - Conjugated by foetal liver - Found in blood

Question 12

What are the methods of PD in ewes?

Answer 12

Non-return to oestrus (16-19 days) - Plasma progesterone assay (15-18 days) - Transabdominal ultrasound (30-50 days) - Vaginal biopsy

Question 13

What are the methods of PD in goats?

Answer 13

Failure to return to oestrus (21 days) - Milk/plasma progesterone assay (21 days) - Oestrone sulphate in milk/plasma (50 days) - Transabdominal ultrasound (30 days) - Abdominal palpation (60-70 days)

Question 14

What are the main methods of PD in sows?

Answer 14

Non-return to oestrus (18-22 days) - Plasma progesterone assay (16-24 days) - Transrectal ultrasound (12 days)