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Background The dam is considered an important source of microbes for the calf; consequently, the development of calf microbiota may vary with farming system due to differences between the contact the calf has with the dam. The objective of this study was to characterise the early changes in the composition of oral and faecal microbiota in beef and dairy calves (N = 10) using high-throughput sequencing of the 16S rRNA gene. The microbiota of calves was compared to selected anatomical niches on their dams which were likely to contribute to the vertical transfer of microbes. Results A total of 14,125 amplicon sequence variants (ASVs) were identified and taxonomically assigned. The oral microbiota of calves and their dams were composed of more similar microbes after the first 4 weeks of life than immediately after calving. The faecal microbiota of four-week old calves was composed of microbes which were more similar to those found in the oral microbiota of calves and adult cows than the faecal microbiota of adult cows. Specific ASVs were identified in the oral microbiota of four-week old calves that were also present in cow niches at calving, whereas very few ASVs were present in the calf faecal microbiota at four-weeks of age were present in any adult cow niche at calving. These results were observed in both beef and dairy calves. Conclusions We did not observe any marked differences in the maturation of the oral and faecal microbiota between beef or dairy calves, despite dairy calves having very limited contact with their dam. This suggests the development of gastrointestinal microbiota in calves may not be affected by continued vertical transmission of microbes from the dam. Although the calf faecal microbiota changed over the first four-weeks of life, it was composed of microbes which were phylogenetically closer to those in the oral microbiota of calves and adult cows than the faeces of adult cows. There was little evidence of persistent microbial seeding of the calf faeces from anatomical niches on the cow at calving in either beef or dairy animals.

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Background This study aimed to determine the association between the lameness advantage genetic index and four outcomes: sole haemorrhage (SH), sole ulcers (SU), white line lesions (WL), and lameness during mobility scoring. Methods We enrolled 2352 Holstein cows from four predominantly housed dairy herds in the UK. Cows were mobility scored and foot lesions recorded at four time points from before calving to late lactation. Cows were genotyped and genetic indexes were assigned to each cow following national genetic evaluations. Lameness records and genetic indexes were matched for 2107 cows. Four separate multivariable logistic regression models, which included farm and parity as covariables, were used to quantify the association between the lameness advantage index and whether animals were affected by SH, SU, WL, or lameness. Results The odds ratios (95% confidence intervals) for one‐point increases in the lameness advantage index were 0.79 (0.72–0.86), 0.68 (0.59–0.78), 0.94 (0.84–1.04), and 0.82 (0.74–0.91) for SH, SU, WL, and lameness, respectively. The same trends were present when the sire's lameness advantage index was evaluated in place of the animal's own, although the strength of this association was generally weaker. Conclusion The lameness advantage index is associated with SH, SU, and lameness, therefore selection on the lameness advantage index could be considered in herds aiming to reduce lameness. Where genomic testing of heifers is not conducted, sire lameness advantage index may still be effective to reduce SH and SU incidence.

Background The objective of this study was to investigate the association between (sub)clinical mastitis (CM) in the first 30 days in milk (DIM) and the presence of sole ulcers (SU) later in lactation. Methods Holstein cows and heifers were examined for presence of sole haemorrhage and SU before calving, in the first 14 days postcalving and in early lactation (after 30 DIM). CM episodes and somatic cell counts (SCC) measurements were obtained from farm records. Multivariable logistic regression was used for data analysis. Results Odds of SU in early lactation were 2.44 times greater (95% confidence interval [CI] 0.97–5.54) in cows that had CM in the first 30 DIM compared to cows that did not have CM in the first 30 DIM. When cows that had SU precalving or at the calving check were excluded from the dataset, an association of CM in the first 30 DIM with later presence of SU was no longer statistically significant but the same numeric trend still existed (odds ratio [OR] 2.25, 95% CI 0.81–5.34). The odds of SU in early lactation were 1.70 times greater in cows that had high SCC compared to cows that did not have high SCC in the first 100 DIM (95% CI 1.13–2.55). Conclusion An association was found between CM in the first 30 DIM and presence of SU in early lactation (after 30 DIM). Elucidating the mechanism behind this relationship could improve our understanding of the aetiopathogenesis of both diseases and lead to new preventive strategies.