LIVER-ABSCESSES IN FEEDLOT CATTLE .2. INCIDENCE, ECONOMIC IMPORTANCE,AND PREVENTION

In beef cattle, liver abscesses result from aggressive grain-feeding p rograms. The abscesses detected only at slaughter, and cattle seldom e xhibit clinical signs. Liver abscesses are an economic liability to th e produces, the packer, and the consumer of beef. In addition to liver condemnation, the economic impact involves reduced feed intake, reduc ed weight gain, decreased feed efficiency, and decreased carcass yield . Fusobacterium necrophorum is the primary causative agent; Actinomyce s pyogenes is the second most frequently isolated pathogen. Ruminal io ns resulting from acidosis are believed to be the predisposing factors for liver abscess. The control of liver abscesses in feedlot cattle u sually depends on the use of antimicrobial compounds. Five antibiotics (bacitracin, chlortetracycline, oxytetracycline, tylosin, and virgini amycin) are approved for use in preventing liver abscesses in feedlot cattle. Tylosin is the most commonly used and the most effective feed additive.