Effects of dietary composition and feeding management regimen on liver abscess prevalence, growth performance, and carcass outcomes of feedlot steers

Objective: We investigated the independent and interactive effects of dietary starch concentration and feeding management regimen on growth performance, carcass characteristics, and prevalence of liver abscesses in finishing beef cattle. Materials and Methods: Beef steers (n = 720) were assigned to 48 pens in a randomized complete block design, with treatments arranged in a 2 x 2 factorial (12 pens per treatment). Factors were finishing diets with either low (49.1%; CON) or high (64.4%; HOT) starch concentrations and feeding management regimens designed for consistent feed delivery (REG) or randomized variations (ERR) in both feed quantity (85% followed by 115% of the previous 4-d average randomly once per week) and delivery time (randomly delayed for 1, 2, 3, or 4 h twice per week). Results and Discussion: No interactions between diet and feeding management regimen were detected for growth performance, carcass outcomes, or liver abscess prevalence. Steers fed HOT had greater liver abscess frequency (55.1% vs. 33.4%) and a greater proportion of liver scars (46.7% vs. 34.0%) compared with CON. Steers consuming HOT also had less final BW, ADG, DMI, hot carcass weight, marbling score, and calculated YG versus CON. Feeding management regimen did not affect liver abscess frequency, growth performance, or carcass merit. Implications and Applications: Feeding a highstarch diet increased liver abscess prevalence and decreased growth and affected carcass outcomes. In contrast, erratic feeding management did not affect liver or production outcomes.