Farrowing and lactation are two of the most critical phases of pork production. A relatively high proportion of pig losses occurs during these periods. Rapid bacterial colonisation of piglets’ sterile gut and underdeveloped immune system represents a very dangerous combination of events. The most significant factors affecting the microflora of the piglet’s gut is its mother and the environment into which it is born. Therefore, management interventions and nutritional regimes that influence the microbiology of the sow’s faeces in a beneficial way are likely also to influence the neonate. Work at the University of Plymouth and at Foulum in Denmark has shown that feed may be fermented successfully with lactic acid bacteria (LAB) and that this process reduces the number of salmonellae and coliforms in the feed and consequently in the lower gastrointestinal tract (Brooks et al. 2001). Recent studies strongly support the hypothesis that orally administered LAB stimulate the immune system, both at the local and systemic level. This combination of effective immunity and reduced level of environmental contamination with faecal pathogens can lead to improved management of sows for increased litter size and weight at weaning time.