Variation in the early-life interdigital skin microbiota of lambs in a commercial sheep flock.

INTRODUCTION

The factors shaping early-life microbial colonisation of the ovine interdigital skin, and their potential relevance to foot health and footrot susceptibility, remain poorly understood. Here, we investigated variation in the interdigital skin microbiota among lambs in different age-location groups.

METHODS

Interdigital skin swabs were collected from all four feet of 25 lambs aged 0-15 days on a commercial farm. Bacterial community composition was characterised using 16S rRNA gene amplicon sequencing, and quantitative PCR was used to estimate total bacterial load and detect Dichelobacter nodosus.

RESULTS

Community composition differed markedly among lamb age-location groups. Microbial communities were more tightly clustered in newborn lambs than in older lambs and total bacterial load was higher in lambs ≥ 1 day old. A consistent early-life core microbiome, dominated by Staphylococcaceae and Corynebacteriaceae, was detected across all groups, although dominant amplicon sequence variants (ASVs) differed among age-location groups. D. nodosus was not detected in any lambs; however, ASVs assigned to the genus Porphyromonas were detected in the interdigital skin microbiota at birth.

DISCUSSION: These findings demonstrate substantial variation in the early-life interdigital skin microbiota among lamb age-location groups, providing a baseline for future studies investigating microbial community development and ovine footrot.