PD in Farm Animals

Question 1

what is PD useful for?

Answer 1

• time for drying off of cattle, parturition date

- accurate feeding of sheep based on no. of foetuses

Question 2

What are the 4 broad methods of PD?

Answer 2

• non-return to oestrus in polyoestrus species
• measurement of hormones [innaccurate]
• detection of gravid uterus (manual palpation/ultraosund/radiography)
• ID changes in gross and microoscopic structure of genital system

Question 3

What prevents luteolysis in the pregnant cow? From what day is this produced?

Answer 3

IFNtau from d13

Question 4

What stage of pregnancy are the majority of pregnancy losses?

Answer 4

Before 21d

Question 5

Give the 4 specific methods of pregnancy detection in the cow

Answer 5

• Non return to oestrus after service 18-24d
• B mode real time ultrasound from d30 (when embreyp detaches from uterus wall, v. innaccurate unless experienced)
• P4 in plasma and milk d21-24
• Membrane slip of chorioallantois on palpation from d33 OR disparity in horn size from d35 OR palpation of foetus from d45–60 OR presence of placentomes d80

Question 6

What is the amnion wrt the foetus?

Answer 6

Small ball surounding foetus

Question 7

What is the blood supply to the uterus? How may this assist PD?

Answer 7

middle uterine a. can be palpated in broad ligament with fremitus

Question 8

What i produced after d 105 that can be used to detect pregnancy?

Answer 8

• foeto-placental unit produces oestrone sulphate - detectable in milk and plasma

Question 9

At what stage post insemination can P4 be used to PD?

Answer 9

d18-d24 - if not pregnant, P4 will be low
if pregnant, P4 will be high
- BUT If high, may be due to other reason! so more a test for NON-pregnancy

Question 10

What is the best substance to test for P4 in?

Answer 10

milk - higher concentrations than plasma

Question 11

Potential causes of high P4 in non-pregnant cow ?

Answer 11

• Luteinised cysts
• persistent CL
• Error in ID?/labelling
• shorter than normal oestrus cycle
• incorrect AI timing
• embreyo mortality
• inadequate sample mixing

Question 12

How does the non-pregnant uterus appear on US?

Answer 12

highly folded with no lumen

Question 13

What may fluid in the uterus indicate?

Answer 13

• oestrus
• pregnancy
• endometiritis

Question 14

By hat day of pregnancy does msot of the pregnant horn has chorioallantois?

Answer 14

d35

Question 15

What does membrane slip help to differentiate/

Answer 15

PYo and pregnancy

Question 16

Why may disparity in horn size give false positives?

Answer 16

• incomplete involution
• fluid in horns
• pyometra
• mucometria
• hydrometria

Question 17

How may oestrone sulphate be detected?

Answer 17

• blood sample from d120 (potentially from d105)

Question 18

How may pregnancy be detected in the ewe?

Answer 18

• Non-return to oestrus 16-19d after service
• plasma P4 15-18d after service
• Transabdo B- Mode US from d30 (no. foetuses from d45-50)
• doppler US d50
• vaginal biopsy
• caudal uterine a. palaption d60
• radiography

Question 19

PD specifics for goats

Answer 19

• failure to return to oestrus d21 after service
• milk/plasma P4 d21 (false positice in pseudoprganancy)
• oestrone sulphateplasma/milk d50
• transab B modeUS from 30d
• abdo palpation from d60

Question 20

PD specifics for sow

Answer 20

• non-return to oestrus d18-22 after service
• plasma P4 16-24d after service
• transrectal B mode US d12
• oestrone sulphate plasma 24-28d after service
• vaginal biopsy 18-22d post service
• rectal palpation 30d
• transabdo B mode US from 24d
• transabdo A mode (audio) from d30
• transrectal doppler US from d25