DEVELOPMENT OF INTESTINAL LACTOBACILLI IN NORMAL PIGLETS

The development of intestinal Lactobacillus spp. in 18 normal piglets from six litters was investigated from 1 to 45 d after birth. Faecal L actobacillus strains isolated from piglets and their dams mere identif ied at species and biovar levels on the basis of carbohydrate fermenta tion. A definite pattern was observed in the changes of four species a nd 20 biovars of lactobacilli appearing in faeces, with growth of the piglets. Lactobacillus reuteri colonized the animals on the first day of birth. The Lact. acidophilus group appeared 1 week after birth and maintained high levels in the intestine. Biovars B, C and E of Lact. r euteri were recovered as major biovars on the first to fourteenth days after birth. In the third and fourth weeks after birth, however, biov ars F and G of Lact. reuteri were mainly recovered from piglet faeces. By the seventh week, biovars B, C and E predominated again in the int estine. No change in the composition of species and biovars of the gen us Lactobacillus in the dams was detected.