By Dr Francois van Niekerk, Humansdorp Veterinary Clinic

The experience of many pig producers is that farrowing attendants on night duty are notoriously unreliable. Reducing farrowing spread and night-time farrowings can help to reduce losses. Prostaglandins have been successfully used for this purpose.Trial One

In June/July 2000 an on-farm trial to assess the efficacy of Estrumate (Cloprostenol 250 mcg/ml, Schering Plough AH) in the reduction of piglet stillbirths was conducted on a 700 sow unit in the Eastern Cape.

The majority of the sows were inseminated on Tuesdays. The average gestation length on the unit was 114 days. Sows were injected with 0.7ml Cloprostenol (Estrumate) at 08h00 on day 113 (Wednesday) and with oxytocin at noon on day 114 (Thursday) if farrowing had not occurred by that time.

Results of the trial are reflected in Table 1.

Stillbirths in the year to May 2000 (ie in the 12 months preceding the trial) were 0.9/litter.

Stillbirths during period 07/06 to 05/07 (ie during the trial) were 44 stillbirths in 81 litters = 0.54/litter, thus an improvement of 0.36 piglets per litter.

With a pre-weaning mortality of 11%, an extra 0.36 X 89% = 0.32 piglets would survive to weaning.

Conclusions after Trial One

• Induction of farrowing with Cloprostenol did not measurably reduce the number of night-time farrowings, but did ensure that all sows farrowed before Friday evening (and thus eliminated weekend farrowings).

• Night-time attendance could be reduced to one night only (the night after injection).

• Management and farrowing attendants could focus on farrowing over a short period.

• The trial proved that induction of farrowing can be very cost-effective if managed correctly.

• Even better results were possible by injecting two days before average farrowing date rather than only one day before expected farrowing date as done in Trial One.

Trial Two

Subsequently day of injection of Cloprostenol was changed to Tuesday (day 112). Results of five weeks farrowings using the latter regime on the same farm (Trial Two) are reflected in Table 2.

Stillbirths during this period were 39/82 = 0.48/litter which was an improvement of 0.42 piglets per litter over the year to May 2002, thus better results than the first trial.

Financial implications

Assume the the current values are approximately: Cost of Cloprostenol (240/20ml = R12/ml = R8.40/dose of 0.7ml. Value of weaner pig: R220 at four weeks.

Assume also that reduction in stillborn rate = 0.3 piglets per litter (Trials One and Two both gave better results than this) and that 700 sows on this farm yield 2.2 litters per annum = 1 540 litters per annum.

Thus, an extra 0.30 piglets, surviving to weaning represents extra income of R66 (0.3 X R220) per litter X 1 540 litters = R101 640 per annum.

Cost of Cloprostenol @ R8.40/dose X 1 540 litters = R 12 936. Thus margin over cost of Cloprostenol = R88 704.

Conclusions

• Induction of farrowing using Cloprostenol has significant potential for increasing profits.
• Induction of farrowing should be considered and evaluated in units in which management is good and which have accurate records.
• Break-even point to cover cost of Cloprostenol is a reduction in still-birth rate of only 0.03 piglets/litter.

Warning

Good management, accurate service records and accurate average gestation lengths are essential to avoid birth of non-viable piglets which can result if injections of prostaglandin are incorrectly timed.

Acknowledgements

Tony Mote and Dave Inkin are thanked for their assistance.