This is a specialised technique for producing high health status breeding stock from a disease herd. It is used mainly by breeding (seed stock) companies rather than commercial producers although systems such as three-site and multi-site production which have evolved from it, are highly applicable to commercial production.

Basically, Medicated Early Weaning (MEW) breaks the cycle of infection by farrowing groups of sows in isolation and weaning their piglets to clean premises at about 5-7 days of age. Medication of the sow and piglets, and sometimes vaccination of the sow, are added safeguards depending upon what particular infections are to be eliminated.

This method produces excellent results in removing most bacterial infections. However, it is possible to produce a pig that is so devoid of pig organisms, that it cannot be acclimatised into conventional herds. Also if a new herd is established by this method it can be very susceptible to even low pathogenic organisms. The technique is used mainly to establish new high health herds.

Procedures

• Sows are moved into isolated farrowing houses at least 5 days before farrowing, 800m from the nearest pig.
• An all in - all out system is used. Each batch of sows is washed prior to entry.
• Farrowing is induced with prostaglandin injections at day 113.
• Sows are medicated from entry into the farrowing house until the piglets are weaned.
• The piglets are weaned at 5 days and reared in groups in isolated housing.
• The piglets are medicated from birth to 10 days of age.

A possible medication regime

Sows

• Injected with potentiated sulphonamide containing 40mg trimethoprim, 200mg sulphonamide/ml (TMS), on entry into the farrowing accommodation at the recommended treatment level.
• From entry to weaning the feed is medicated with TMS at therapeutic doses, and water soluble tiamulin is given twice daily.

Piglets

• Injected daily with TMS until weaning.
• Post weaned pigs - Injected with TMS and dosed orally daily with tiamulin for 5 days.

Bacterial diseases that can be eradicated by MEW:

• Actinobacillus pleuropneumonia
• Atrophic rhinitis
• Enzootic pneumonia
• Glässers disease (Haemophilus parasuis)
• Mange (Treatment of the sow with ivermectins is required).
• Streptococcal meningitis
• Swine dysentery