Fig. 4

a Shannon diversity increases with age and approaches adult sow microbiota diversity. b Mean Bray–Curtis dissimilarity between piglets and unrelated sows on the same farm. Significance calculated by Wilcoxon Rank Sum Test is indicated, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001. c) Total litter effect measured in mean Bray–Curtis dissimilarity between siblings at each timepoint. While each point in a) and b) represents a single piglet, each point in c) represents a litter, and its y-axis value is the mean of all possible pairwise comparisons between the siblings. Red horizontal lines indicate the mean dissimilarity between all piglets at the timepoint. The mean dissimilarity between all piglets was comparable to that between the unrelated sows (mean = 0.48, not shown)