Retrospective analysis of illness and liver abscesses in low-risk, crossbred beef cattle.

BACKGROUND

Liver abscesses are a major economic concern in beef production, yet the relationship between therapeutic health events and liver abscess development remains poorly understood. This study evaluates how health diagnoses, therapeutic treatments, and the timing of these events across the production cycle relate to liver abscess prevalence in a large population of low-risk, crossbred beef cattle.

METHODS

Binary liver abscess phenotypes and lifetime treatment records were analyzed for 9,527 animals using generalized linear mixed models. Health events were summarized by diagnosis, treatment type, and antibiotic class during preweaning, feedlot, and lifetime phases.

RESULTS

Although overall therapeutic antibiotic treatment was not associated with liver abscess development (p > 0.10), specific antibiotic classes showed sex-dependent relationships. Steers treated with tulathromycin preweaning or at any time had a reduced risk of liver abscesses compared to untreated steers (p = 0.02). In contrast, no effect was detected in heifers. A sex-by-oxytetracycline interaction was also identified (p = 0.01) but with no significant pairwise contrasts (p > 0.10). Heifers diagnosed with infections, primarily infectious bovine keratoconjunctivitis, were less likely to have liver abscesses than heifers without infections (p = 0.03).

CONCLUSION

These findings indicate that early-life health events, particularly preweaning antibiotic treatments, may have lasting effects on liver abscess susceptibility based on this observational study. Experimental research is needed to validate these results. The research highlights the need for mechanistic studies to clarify biological pathways and support the development of non-antimicrobial prevention strategies.