Induction of parturition and abortion in cattle, sheep, goats and pigs

Question 1

indications for induction of parturition in cattle

Answer 1

Preserve the life of the sam
reduced dystocia by reducing foetal birth weight in heifers carrying oversized calves
Mismated animals
schedules caeseran section - by giving oxytocin - high value calf or an embryo transfer patient
prevent excessive udder oedema - induced parturition for a welfare point of view

Question 2

What are the disadvantages of calving induction

Answer 2

Public attitude to the industry- public look unfavourably on the practice
Can reduce birth weight and weaning weight in beef herds
Calf mortality < 2weels from due date - welfare issues and loss of calves
Immunosuppression, peracute mastitis, photosensitisation ==> can be see in some cows treated with long acting
Metritis, hypocalcaemia, dystocia can occur
Corticosteroids are immunosuppressive

Question 3

Cows selected for induction should be

Answer 3

aged 3-8
BCS 4.5 -5.5/8
in good health
avoid cows with residual mammary gland infection or if treated for severe mastitis during the year

Question 4

adverse conditions associated with calving induction

Answer 4

Mastitis
metabolic disease can be more severe
retained foetal membranes; increased incidence
peracute infections
photosensitisation
increased calf mortality, impaired absorption of colostrum, decreased immunity, decreased growth rates

Question 5

what are the two main methods of inducing parturition in cattle

Answer 5

Corticosteroids

Prostaglandins

Question 6

when would you use short acting corticosteroids

Answer 6

Dexamethasone
80-90% efficacy when given within 2 weeks of normal term
Parturition occurs 24-72 hours
If have not calved within 72 hours treat again

Question 7

when would you use long acting corticosteroids

Answer 7

Dexamethasome timethyl acetate
Used to in cows > 7 months gestation and the udder is distended
Post injection monitor cows from 20min for anaphylactic reaction; if occur administer antihistamine or adrenalin
Calving occurs 4-26days post treatment

Main aim = to reduce culling rate

Question 8

When would you induce

Answer 8

Best if given in last 2 weeks of gestation
Time to calving: 24-72hours (mean of 45hours)
High rate of RFM (retained foetal membrane)

Question 9

How does pgf2alpha induce abortion

Answer 9

PGf2alpha causes abortion when administered from day 7 to 150 by causing luteolysis
> day 150 to 240 ability to cause abortion is variable depending upon the degree to which pregnancy can be supported by placental production of progesterones
> 240 days Pgf2alpah induce parturition within 2-3days

Question 10

Explained the combined used of corticosteroids and prostaglandins

Answer 10

Corticosteroids help decreased placental production of progesterone
Pg- removes production of progesterone from the CL
Combining treatments has improved the response rate and reduced the variability in response

Question 11

what is the disadvantage of using corticosteroids and Pg

Answer 11

if parturition occurs to soon after treatment dystocia can occur due to inadequate time for the normal softening of the birth canal to occur

Question 12

Abortion of abortion/ parturition in sheep

Answer 12

> 120 days dexamethasone 15 to 20mg IM - parturition within 48h - the placental takes over the production of progesterone from the CL - therefore prostaglandins may not terminate the pregnancy

oestrodial benzoate - reliable in late gestation > 140days

Question 13

Goat induction or parturition

Answer 13

for viable kids best to induce >144 days of gestation
PGf2alpah from day 4 to term will terminate pragnancy (CL required throughout the pregancy of the doe)
Dexamethasome - >144 days
Oestardiaol benzoate >120days

Question 14

Pigs induction or parturition

Answer 14

Induce > day 110 to ensure good viability of piglets
PGF2alpah > 110 days, farrowing 20 to 36 hours later

To induce abortion; pgf2alpah after day 12