Reproductive Technologies Flashcards
Why do pregnancy diagnosis?
If pregnancy is present Identify non-pregnant Foetus viable Litter size (feeding, pups, mares) Due-date Foetal sexing
Methods of pregnancy diagnosis
Rectal Exam
Ultrasonography
Hormone Assays
Rectal Exam
Ads- not much equipment
Disadvs- animal needs to be large enough
Detect- Horn enlargement, fluid, membrane slip, fetus, cotyledons, fremitus
Challenge- to be absolutely sure not pregnant/pregnant
Timing- cattle about 35 days, horse-20-30 days
Ultrasonography
Cattle and horses- transrectally
Deer- probe in splint device
Alpacas/dog/cat- transabdominally (lower risk of injury)
Fluid on ultrasound- black
When can you use ultrasonography in cattle?
28-30 days
Measurements of age
Biparietal parameter Can see entire embryo Ruminants- can detect when cotyledons develop Mare- how thick placenta Crown-romp length
What hormones can you detect in hormone assays?
Progesterone
Pregnancy-associated proteins
PMSG/ ECG (Equines)
Oestrone sulphate
Pregnancy Diagnosis in small animals
Palpation (transabdominal, feel spheres ~1cm, need good BCS
Ultrasonography
(Radiography)
Advantages of artificial insemination
Wider genetic pool Known traits (selection control) Sex semen Less injury/risks Biosecurity Controllable Trade between countries
Disadvantages of artificial insemination
Oestrus detection/control (labour intensive)
Handling
Cost??
Human factor (process of freezing semen could damage, correct heat detection and correct insemination technique)
AI allows to reproduce from superior males at a ………..
Much higher rate
Storage of semen
Liquid nitrogen (flask)
1/2, 1/4ml straws
More common fresh in horse and Boars (harder to freeze)
Timing in cattle
AM/PM rule
Oestrus on average 9-14 hours
Ovulation 12-18 hours after end of oestrus
Allow time for sperm maturation/movement
Where to inseminate in:
Cattle
Sow
Horse
Cattle- into horn
Sow- part way into cervix (spiral shaped)
Horse- cervix
AI in bitch
Transvaginal or cervical
Surgical insemination not allowed in UK (animal welfare legislation)
Sex semen
X semen contain more DNA
Attract more dye
2 methods:
Flow cytometry (pass through electro-static field)
Sperm deactivation by laser (less harmful to sperm)
Inseminate deep into horn on side where ovulation occurred and corpus leuteum formed as contain even less semen
MOET
Multiple Ovulation & Embryo Transfer
Stimulate females to super ovulate- produce multiple follicles and
What kind of species is MOET good for?
Species with long gestation length and 1 or 2 offspring e.g. cattle, mare, camelids
