Back G. M. Williams
Southbridge, Canterbury, New Zealand
Abstract
The study was done in a pig breeding/grower unit in 40 heactares where observations were made in three phases, namely, pre-EM use, transition to EM use and current use of EM. The outdoor breeding unit had 90 sows and 8 boars exposed to natural mating with piglets weaned where 4 weeks old. The indoor grower unit had 600 pig places in 30 pens with the pigs being moved progressively through increasing pen sizes and slaughtered at 20 weeks.
During the pre-EM phase wormers and antibiotics were used which were progressively phased out during the transition phase and completely stopped during the current phase. There was a noticeable improvement in the health of weaners aged 4 - 7 weeks. The age of slaughter of pigs were reduced due to improved growth, odour control in grower sheds improved and when irrigating effluent on to the pasture. Moreover there was a dramatic reduction of costs of infeed wormers, infeed antibiotics and De-oderase.