It is essential that the newborn piglet obtains a good intake of colostrum. The internal absorption of colostral antibodies by the piglet’s gut is of tremendous importance, as newborns do not synthesise any appreciable level of antibody before the age of 3-4 weeks. Recent UK data showed that an average of 10 % of potential growing pigs die before weaning (Meat and Livestock Commission, 2001). In addition to representing a serious economic impact, these high pre-weaning mortality rates are also unacceptable from an animal welfare viewpoint. A review of the literature shows that there are considerable number of studies, which report the use of various Lactobacillus strains as probiotic agents. In addition to their nutritional and antimicrobial effects, many of them have immunomodulatory activity. This study investigated the effects of liquid feed, fermented with porcine Lactobacillus salivarius, on the quality of colostrum produced in terms of its mitogenic activity as well as immunoglobulin, protein and lysozyme contents.