For example, Main etal.(2004) found
that mortality rate decreased from 5.3% for pigs weaned at
12 days to 0.5% for pigs weaned at 21 days. It should be
noted that, the mortality rate of the pigs weaned at 3
weeks of age in the present study (14%)is much higher
than that normally found for pigs weaned at the same age
at our centre or in previous studies (e.g. 0.5%, Main etal.,
2004; 1.0%, Smith etal.,2008).