Flashcards in PD in Farm Animals Deck (20):
what is PD useful for?
- time for drying off of cattle, parturition date
- accurate feeding of sheep based on no. of foetuses
What are the 4 broad methods of PD?
- 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
What prevents luteolysis in the pregnant cow? From what day is this produced?
IFNtau from d13
What stage of pregnancy are the majority of pregnancy losses?
Give the 4 specific methods of pregnancy detection in the cow
- 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
What is the amnion wrt the foetus?
Small ball surounding foetus
What is the blood supply to the uterus? How may this assist PD?
middle uterine a. can be palpated in broad ligament with fremitus
What i produced after d 105 that can be used to detect pregnancy?
- foeto-placental unit produces oestrone sulphate - detectable in milk and plasma
At what stage post insemination can P4 be used to PD?
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
What is the best substance to test for P4 in?
milk - higher concentrations than plasma
Potential causes of high P4 in non-pregnant cow ?
- Luteinised cysts
- persistent CL
- Error in ID?/labelling
- shorter than normal oestrus cycle
- incorrect AI timing
- embreyo mortality
- inadequate sample mixing
How does the non-pregnant uterus appear on US?
highly folded with no lumen
What may fluid in the uterus indicate?
By hat day of pregnancy does msot of the pregnant horn has chorioallantois?
What does membrane slip help to differentiate/
PYo and pregnancy
Why may disparity in horn size give false positives?
- incomplete involution
- fluid in horns
How may oestrone sulphate be detected?
- blood sample from d120 (potentially from d105)
How may pregnancy be detected in the ewe?
- 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
PD specifics for goats
- 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