Determinants of the gut microbiota development in piglets and its relationship to performance

Abstract

The role of the microbiota in host health and metabolic phenotype is of increasing interest, with perturbations to the microbiota in early life influencing long term health conditions. The aim of this thesis was to establish factors affecting the neonatal piglet microbiota development and to identify microbiota markers associated with superior piglet growth. Longitudinal analysis revealed that, whilst piglet age was the main determinant of microbiota development over the first 8 weeks of life, differences in faecal microbiota richness and genera abundance were associated with piglet birthweight. The abundance of several identified genera was higher in piglets with superior growth rates during early life. The sow is an important source of microbiota seeding to neonatal piglets. Sow faecal microbiota changed significantly during the periparturient period and differed between parities, with primiparous sows exhibiting a lower microbiota diversity than multiparous sows. Early life piglet microbiota community composition was more like the maternal areolar skin microbiota immediately after birth but became increasingly similar to the maternal faecal microbiota with time. In a reciprocal cross-fostering model between primiparous and multiparous sows, a litter specific neonatal piglet microbiota existed for the first three days of life, with siblings separated by cross-fostering retaining a more similar microbiota composition than non-siblings in the same litter. Non-fostered primiparous progeny had lower neonatal microbiota diversity and pre-weaning growth, whilst cross-fostered piglets developed a more diverse neonatal microbiota. Administration during the neonatal period of an autogenous Enterococcus faecium strain, previously associated with superior piglet growth was unsuccessful in improving pre- or postweaning performance, but reduced diarrhoea occurrence. In conclusion, early life microbiota markers associated with birthweight and growth have been identified. Sow microbiota sources, sow parity and standard management practices, such as cross-fostering influence piglet microbiota development. Exploiting this knowledge could help to design management strategies aimed at improving piglet performance through microbiota manipulation.