Late weaning is associated with increased microbial diversity and Faecalibacterium prausnitzii abundance in the fecal microbiota of piglets

Abstract

Background: In pig production systems, weaning is a crucial period characterized by nutritional, environmental, and social stresses. Piglets transition from a milk-based diet to a solid, more complex plant-based diet, and their gut physiology must adapt accordingly. It is well established that piglets weaned later display improved health, better wean-to-finish growth performance, and lower mortality rates. The aim of this study was to evaluate the impact of weaning age on fecal microbiota diversity and composition in piglets. Forty-eight Large White piglets were divided into 4 groups of 12 animals that were weaned at different ages: 14 days (early weaning), 21 days (a common weaning age in intensive pig farming), 28 days (idem), and 42 days (late weaning). Microbiota composition was assessed in each group by sequencing the 16S rRNA gene using fecal samples taken on the day of weaning, 7 days later, and at 60 days of age.

Results: In each group, there were significant differences in fecal microbiota composition before and after weaning (p < 0.05), confirming that weaning can drastically change the gut microbiota. Microbiota diversity was positively correlated with weaning age: microbial alpha diversity and richness were higher in piglets weaned at 42 days of age both on the day of weaning and 7 days later. The abundance of Faecalibacterium prausnitzii operational taxonomic units (OTUs) was also higher in piglets weaned at 42 days of age.

Conclusions: Overall, these results show that late weaning increased gut microbiota diversity and the abundance of F. prausnitzii, a microorganism with positive effects in humans. Piglets might thus derive a competitive advantage from later weaning because they have more time to accumulate a higher diversity of potentially beneficial microbes prior to the stressful and risky weaning period.

Keywords: Age; Diversity; F. Prausnitzii; Gut microbiota; Piglet; Weaning.

Fig. 1

Growth curves for piglets weaned at 14 days of age (W14), 21 days of age (W21), 28 days of age (W28), and 42 days of age (W42). The solid and dashed lines show each group’s mean and standard deviation, respectively. The initial sample sizes for each group were as follows: W14: 10 animals, W21: 12 animals, W28: 12 animals, and W42: 10 animals. The samples sizes for each group after weaning were as follows: W14: 4 animals, W21: 6 animals, W28: 6 animals, and W42: 5 animals. Any statistical differences between groups are indicated by different letters in each time point, and further details can be found in Additional file 5: Table S1

Fig. 2

Relative abundance of the different microbial phyla (a) and genera (b) at each sampling point for every individual pig in each weaning group. Only genera present in at least 20% of the piglets are shown

Fig. 3

Boxplots of alpha diversity (a), beta diversity (b), and richness (c) for each sampling point for piglets weaned at 14 days of age (W14), 21 days of age (W21), 28 days of age (W28), and 42 days of age (W42). Any statistical differences are indicated in the figure (*p < 0.05, **p < 0.01, and ***p < 0.001)

Fig. 4

NMDS plots showing microbiota composition at each sampling point within each weaning group (a: piglets weaned at 14 days of age; b: piglets weaned at 21 days of age; c: piglets weaned at 28 days of age; and d: piglets weaned at 42 days of age)

Fig. 5

Abundance of F. prausnitzii at each sampling point for piglets weaned at 14 days of age (W14), 21 days of age (W21), 28 days of age (W28), and 42 days of age (W42). The normalized abundances of the three OTUs annotated as F. prausnitzii (OTU IDs 851,865, 350,121, and 25,215) were summed for each individual sample