induction

natural induction

maturation of fetal hypothalamus/pit = release of fetal ACTH and cortisol

what does fetal cortisol cause

1. trophoblast to release PGF2a = maternal luteolysis and activation of myometrium

• maternal luteolysis = prog drop and cervical dilation

2. increased synth of etsrogens by trophoblast = activstion of myometrium

artificial induction indications

• calving in time when skilled assistance is available

• reducing birth weight by shortening gestation ( fetus gains about 0.5 kg/day during the last weeks of normal gestation) to prevent dystocia

• in diseased or injured cow or when termination will improve condition of cow

• when live calf can be obtained before slaughter

• To prevent udder edema and distension that predisposes difficulty in milking which may lead to mastitis

• Advancing the time of calving to coincide with the availability of suitable pasture for enhancing milk production. 

disadv od artificial inductions

• decr birth weight if calves

• increase incidence of retined fetal membrane

• milk yield is initially affected and delay in reaching peak lactation

• decre colostrum quality and quantity

• not always effective

induction in cows

should not be more than two weeks from natural birth

1. corticosteroids

2. prostaglandins and analogs

3. dexamethasone (20mg) and cloprostenol (.5mg)

induction in cows- corticosteroids

removes placental progesterone and converts it to estrogen

• number of synthetic corticosteroids avalible- short, medium and long term (all are immunosupressive so if infection present give broadspectrum antibiotics (check lungs and udder before giving)

ex. short-acting dexmethasome

• 20-30mg im injection induces parturition within 24-72 hrs

*only effective when fetus alive

induction in cows- prostaglandins and analogs

*removes ovarian sourse of progesterone

• effective after day 250 of pregnancy

ex. cloprostenol

• .5mg induces parturtion in 24-72hrs

induction in cows- dexamethasone and cloprostenol

dexa- 20mg

clopro- .5mg

induce parturition in 24-42hrs

what is not used for induction of sows

coticosteroids

chatgbt:

To induce farrowing, you must destroy the CL so progesterone drops.

• The CL in sows is not very responsive to corticosteroids.

induction of sows

1. prostaglandin analog

2. oxytocin

induction of sows- prostaglandin analog

after day 111

ex- clopro- .125mg induces parturition within 24-30 hrs of admin

induction of sows- oxytocin

20-30 IV induces parturition in 30 mins#

30 IV oxytocin 20-24 hrs after PGF2a- parturition in 27hrs

induction of sheep

corticosteroid

pg2fa

induction of sheep- corticosteroid

dexathasome- 16mg induces in 72 hrs

induction of sheep- pg2fa

clorpo .125mg induces in 48hrs

induction of goats- corticosteroids

dexamethasone 20mg induces 24-48hrs

induction of goats- pg2fa

clopro .125mg in 36hrs