A new study, published in Nature, has concluded that increasing the physical complexity of the rearing environment can provide sub-optimal conditions for establishing a healthy microbial community in growing pigs when compared to rearing in a simpler, slatted system.
The main objective of the study was to characterise the impact of simple-slatted (S) and complex straw-based (C) rearing environments on the respiratory (bronchus), gut (ileum and colon) mucosa-associated bacteriome, and gut (faecal) luminal-associated bacteriome structure and diversity in growing pigs. It was hoped that this investigation would further current understanding of the interplay between rearing environments and the long-term health and productivity of pigs.
In the investigation, 175 weaned pigs from 25 litters were randomly assigned one of two rearing environments: simple slatted-floor (S) or complex straw-based rearing ecosystem (C). At the time of slaughter, 164 days post-weaning, samples were taken from the rearing pen floor, and faecal swabs and mucosal scraping samples from bronchus, ileum, and colon were collected.
Analysis of the samples taken from pigs reared in the S (simple-slatted) ecosystem showed a higher α-diversity of respiratory and gut microbiota compared to samples from those in the C system. Moreover, the C system reared pigs had a significantly lower Firmicutes/Bacteroidetes ratio in the bronchus, ileum, and colon, than the S system pigs. The unfavourable pathogenic taxa Psychrobacter, Corynebacterium, Actinobacteria, and Neisseria were the signature taxa of C environment-associated microbial community.
The microbiota of pigs reared in the simple, slatted systems contains a significantly higher density of the most essential and beneficial bacterial taxa compared to that of the pigs reared in the complex system.
