LAUSR

The backgrounding period is a post-weaning management strategy to add weight and build the health status in beef calves. This phase is used to prepare beef calves to enter the next phase of the production supply chain. Weaning and backgrounding management methods can be strategies to reduce calf morbidity and mortality in the feedlot. The objective of this study was to assess beef calf growth performance based on weaning management strategy and subsequent backgrounding using commonly used forage-based diets by Alabama beef producers. A two-year study was conducted using 427 steers (n = 216, year 1, average BW 306kg; n = 213, year 2, average BW 294kg). Steer calves from three Auburn University research farms were randomly assigned based on weaning weights to one of three different weaning method groups: fenceline weaning, nose-flap weaning, or abrupt weaning. After the weaning period calves were brought to a centralized farm and began a 60-d backgrounding period where they were randomized according to previous weaning management, farm of origin and body weight to one of three nutritional management strategies in a 3×3 factorial design: cool-season baleage (oats, ryegrass and crimson clover) and 1% BW dried distillers’ grains (DDGS), bermudagrass hay and 1% BW DDGS, or grazing mixed warm-season annuals and 1% BW DDGS. Body weights were collected on d 0, 30 and 60 of the backgrounding phase. In both years, fenceline weaned calves had the greatest average daily gain (year 1, 0.76 kg/d; year 2, 1.03 kg/d; P = 0.0225) in the first 30 days of the backgrounding period regardless of backgrounding diet type. Calves fed the bermudagrass hay-based diet also had a greater average daily (year 1, 0.78 kg/d; year 2, 1.24 kg/d; P < 0.0001) than both the grazing and baleage diet groups in the first 30 days of backgrounding. From d 30 to 60 of backgrounding in each year, calves on the hay-based diet had the least average daily gain (year 1, 0.19 kg/d; year 2, 0.42 kg/d; P < 0.0001). Steers on both the warm-season annual grazing and cool-season baleage diets supported greater average daily gains (P =0.0041) during the last 30 days of the backgrounding period (0.74 kg/d and 0.75 kg/d, respectively). Steers in year 2 had a greater total gain (year 1, 45.55kg; year 2, 51.56 kg; P = 0.0042) than steers in year 1. However, results in both years indicate that weaning and backgrounding management strategies may influence calf performance during the transition period into the post-weaning phase.