Development of selected bacterial groups of the rectal microbiota of healthy calves during the first week postpartum.

Aims: The intestinal microbiota of newborn calves is largely unexplored even if it is of great significance for their future health. Therefore, the aim of the study was to gain a better insight into the development dynamics of certain bacterial groups during the first week of life.

Methods And Results: Faecal samples of healthy Simmental calves (dual-purpose breed; n = 80), bottle fed and raised in a dairy farm were taken immediately after birth and at 6/12/24/48/72/168 h (h) after birth. Samples were analysed using cultural, biochemical and molecular-biological methods. The aerobe, anaerobe, Enterobacteriaceae and Enterococcus counts of healthy calves increased significantly between 6 and 24 h postpartum (P <0·05). Apart from the anaerobes, bacterial counts decreased after reaching a plateau at 24-48 h. Enterococcus faecalis was detected in significantly higher counts compared to E. faecium (P <0·05). Lactobacilli developed more slowly and increased until day 7 after birth to a mean value of 6·8 × 10  CFU per g. MALDI-TOF analysis of 2338 lactobacilli isolates resulted in 36 different species.

Conclusions: Lactobacillus reuteri became the most common Lactobacillus sp. during the first week of life.

Significance And Impact Of The Study: This fact seems to be very important for the calf's intestinal health because L. reuteri is known to show in vitro bactericidal effects against bacterial pathogens and anti-infective activities against rotaviruses and Cryptosporidium parvum.