Bovine repro11

• Preserve the life of the dam
• Reduce dystocia by reducing foetal birth weight
• Facilitate close observation for detection and correction of dystocia
• Scheduled caesarian section
• Prevent excessive udder oedema
• Synchronise lacatation, increase lactational yield, improve fertility, decreasing culling in seasonal calving herds & improve lifetime production in potentially late calving cows
• In seasonal herds, once cows calve late, without induction they are committed to a lifetime of late calving

• Calving induction within 2 weeks of due date – calf viability appears normal, lactational yield generally normal.
• Can reduce birth weights and weaning weights in beef herds
• Calf mortality <2 weeks from due date – welfare issues and loss of calves
• Public attitude to the industry – Public look unfavourably on the practice
• Increased incidence of RFM
• Subsequent reproductive performance generally normal but can be
reduced in some animals with RFM

• Immunosuppression, peracute mastitis, photosensitisation & hypersensitivity reaction (vulval swelling, increased respiratory rate, distress, swishing of tail, collapse) can be observed in some cows treated with long acting corticosteroids

• Corticosteroids are immunosuppressive so do not administer in the presence of an infection or administer systemic antibiotics. Tend to avoid induction of older cows (>10 years of age) and first calf heifers (reduced lactational yield) if possible. Avoid cows with residual mammary gland infection or if treated for severe mastitis during the year to avoid flare up of mastitis

• Are there any other alternatives eg cull, split calving, sell late cows to other farmers, carry over late cows to the following year?
• Pregnancy check all cows presented for induction
• Screen out cows that are too old, too young (1st calf heifers), residual mammary gland infections, sick cows, cows with a history of severe milk fever, pregnancy <7 months gestation, low BCS eg (<4, 1- 8 scale)
• Ensure cows have had an adequate dry period (>6 weeks), appropriate transitional management & preventative measures to prevent hypocalcaemia (eg fed anionic salts) are in place
• Ensure calves will be treated humanely, eg non- viable calves identified immediately at birth and euthanised. Extra care for induced calves that are deemed viable
• Ensure that sufficient labour is present to manage, observe and treat induced cows

• Corticosteroids – Short acting – Medium acting – Long acting
• PGF2α or synthetic analogues

• Dexamethasone or flumethasone given as a single IM injection
• Parturition is induced with 80%-90% efficacy when the injection is given
WITHIN 2 WEEKS of normal term.
• The interval from injection to parturition is 24-72 hours, with an average of
48 hours.
• If have not calved within 72 h retreat.
• Practical tip: usually used when cows are close to their due date and have
milk present within their mammary gland

• Primarily used to induce calving in cows which are due to calve late in the
season
• Calf viability not of primary economic importance
• Aiming to reduce culling rate and increase lifetime production performance
• These are often cows that have not conceived to AI but have conceived to a
herd bull which was released with the herd after AI has been completed
• Cows are generally pregnancy tested before treatment to ensure that they
are >7 months pregnant at the time of treatment
• Cows should be ideally screened out for age, mammary gland infections or
other concurrent infections.

• Products used: Dexamethasone trimethyl acetate or triamcinolone acetonide
(4-8 mg) IM
• Calving occurs 4 to 26 days post treatment
• The further a cow is from its due date the longer cows take to calve
• Total milk production per lactation can be reduced by 4%-7%
• Incidence of RFM 9 to 22%
• Variability in time-to-calving after treatment can be reduced by administering a
short-acting corticosteriod or PGF2α about 8 to 12 days after long-acting
corticosteroid treatment
• Most cows will calve 2 to 3 days after the 2nd injection; however, calf mortality
and the incidence of retained placentas will increase with this method, due to
the likelihood that calves were more premature at the time of treatment, hence
the reason for the delay in response to the first treatmen

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

To induce abortion:
• PGF2α 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 d
degree to which pregnancy can be supported by placental production of
progestogens
• >240 days PGF2α induce parturition within 2 to 3 days

• Corticosteroids help decrease 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.

• Disadvantages: if parturition occurs too soon after treatment dystocia can
occur due to inadequate time for the normal softening of the birth canal to
occur
• Better responses are achieved by treating with a long acting corticosteroid,
followed by dexamathosone or PGF2α 8 to 12 days later. Most cows calve
between 24 to 48 h after treatment

• Early pregnancyt ermination/mismating
• 7to<150daysPGF2α
• 210 to 275 days: Long acting corticosteroid

• After administering along acting corticosteriod if cows do not
calve within 8 to 12 days administer a short acting
corticosteroid or PGF2α, most will calve within 72 h
• >282daysPGF2α,or short or medium acting corticosteroid

• >120 days Dexamethasone 15 to 20 mg IM – parturition within 48 h
• Oestradiol benzoate 2 to 20 mg IM
• PGF2α day 5 to 30 to induce abortion, ineffective > Day 30 due to placental
production of progestogens

• For viable kids best to induce >144 days of gestation
• PGF2α from Day 4 to term will terminate pregnancy
(CL required throughout pregnancy in the doe)
• PGF >144 days, parturition within 30 to 35 h
• Dexamethasone IM > Day 144 – all kids reported to be delivered alive
• Oestradiol benzoate >120 days abortion/parturition within 4 days

• Normal gestation length 115 ± 2 days
• Induce > Day 110 to ensure good viability of piglets
• PGF2α given >110 days, farrowing 20 to 36 h later
• Dose: PGF2α (10 mg IM) or cloprostenol (175 μg IM)


To improve synchrony of farrowing:
• PGF2α at 12 pm day before due date, oxytocin 8 am on following day.
Most sows will farrow over next 6 h (during working hours)

To induce abortion: PGF2α after Day 12

c. Dexamethasone

b.Prostaglandin F2 alpha

To induce abortion: PGF2α after Day 12

PGF2α at 12 pm day before due date, oxytocin (5 to 10 IU IM) 8 am on following day. Most sows will farrow over next 6 h (during working hours)

140 days

Dexamethasone 15 to 20 mg IM – parturition within 48 h

Long-acting corticosteroids:
Dexamethasone trimethyl acetate or triamcinolone

Calving occurs 4 to 26 days post treatment
The further a cow is from its due date the longer cows take to
calve

PGF2α day 5 to 30 to induce abortion

abortion within 30-35h (?)

PGF2α from Day 4 to term will terminate pregnancy

abortion within 30-35h

Screen out cows that are:
too old
too young (1st calf heifers)
esidual mammary gland infections
sick cows
cows with a history of severe milk fever
pregnancy <7 months gestation
low BCS eg (<4, 1- 8 scale)