The Level of Selected Bacterial Phyla on the Skin Surface of Small Ruminants According to the Breed and Species

SIMPLE SUMMARY: The skin is one of the largest surface organs for animals. The microbiome of the skin plays an important role in protecting the host. The study showed that the environment in which the animals lived and their size could affect the bacterial composition of their skin. Additionally, individual differences between the bacterial composition of the skin were observed, which may indicate the existence of a factor called “individual influence”. ABSTRACT: For decades, skin has been assigned the main role of an insulator of the inside of the body from the external environment, but it also plays a role in maintaining homeostasis. In this study, the level of selected bacterial phyla (Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria) was assessed in three sheep breeds (Świniarka sheep, Uhruska sheep and BCP line (synthetic sheep breed; n = 6) and in two breeds of goats (Boer, Saenian; n = 6) living in the same environment and fed on the same feed, where the aim was to identify differences in terms of race, species and individual differences. Significant differences were found in Firmicute, Actinobacteria and Proteobacteria phyla (p ≤ 0.05). Statistically significant and positive correlations were demonstrated between Actinobacteria and Proteobacteria, Proteobacteria and Bacteroidetes or Firmicutes and Bacteroidetes. The obtained results suggest that the species and racial differences in the level of the studied bacterial phyla may also result from the physicochemical differences of the skin surface, as they could exacerbate the variations in humidity, temperature, composition of antimicrobial peptides (AMP) and lipid content. In addition, individual differences were observed, which indicate a similar effect of an individual on the microbiological composition of its organism.