Midterm 3 - Lecture 25 Flashcards

1
Q

Why is it important to determine pregnancy status as early and accurately as possible?

A
  • to minimize economic losses and rebreed or cull non-pregnant animals ASAP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the different pregnancy detection methods?

A
  1. Absence of estrus
    - inexpensive, early indicator of pregnancy
  2. Clinical detection
    - rectal exam
    - ultrasonography
  3. Laboratory detection
    - detection of pregnancy associated substances
    - vaginal biopsy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is ‘absence of estrus’ not always a dependable pregnancy diagnosis method?

A
  1. silent heats
  2. retained corpus lutea
  3. early abortion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Rectal examination

A
  • mainly used for large domestic species (cows and mares)
  • somewhat invasive
  • requires training/expertise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Ultrasonography

A
  • non-invasive
  • requires special equipment
  • requires training/expertise required
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

2 methods of ultrasonography pregnancy diagnostics

A
  1. Doppler method
    - sounds
  2. Real time ultrasound
    - images
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Doppler Method (ultrasonography)

A
  • Doppler are particularly suitable for use in pigs, dogs, sheep and goats
  • allows for detection of a number of different indicators of pregnancy (sounds):
    1. increased blood flow in 1 or more uterine arteries
    2. fetal heartbeats
    3. umbilical artery pulsations
    4. fetal movement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does an ultrasound work?

A
  • propagation and interaction of sound waves through body tissue
  • image based on the intensity of the reflected echos
  • no echo: liquid = dark
  • low-intensity echo: low-density tissues (muscle) = grey
  • high-intensity echo: high-density tissues (bones) = bright
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Real time ultrasound - pigs

A
  • allows for non-invasive detection of pregnancy
  • generally done in animals you can’t do a rectal exam in (ex. pigs)
  • requires training, expertise, and equipment ($)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Real time ultrasound - cow or mare

A
  • conformation of estrous cycle/pregnancy
  • ovarian structures
  • embryonic membranes
  • fetus(es)
  • sex
  • go into rectum and probe is placed inside, right over top of the repro tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Using ultrasound pregnancy diagnostics, what is the earliest you can detect pregnancy after mating/insemination of: cattle, horse, pig, sheep, goat

A

Cattle: day 25
Horse: day 18
Pig: day 21
Sheep: day 30
Goat: day 30

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Can substances related to pregnancy be detected in serum or milk? How?

A

Yes! By using assays or tests
- reliable
- relatively inexpensive
- non-invasive
- requires purchase of on-farm assays or access to diagnostic services

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What assays are capable of accurately measuring several different hormones associated with pregnancy?

A
  1. Sensitive radio immunoassays (RIA)
  2. Enzyme-linked immunosorbant assay (ELISA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What hormone is most commonly associated with pregnancy?

A

P4
- commercial on-farm milk tests for cattle are common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Other than P4, what are some hormone indicators of pregnancy?

A
  1. Estrone sulphate
    - compound produced by the fetus and measurable in maternal plasma, milk, urine or fecal matter
  2. Gonadotropins
    - eCG: appears in the blood of pregnant mares as early as day 40 and is also measurable in urine
    - hCG: appears in the blood and urine of pregnant women
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Prior to the commercial availability of assays, what was used to detect pregnancy on-farm? How?

A
  • Vaginal biopsies; vaginal epithelium changes w/ pregnancy (cell layers reduced)
  • vaginal tissue is biopsied, fixed, stained & examined microscopically
  • requires access to a diagnostic lab