Effects of Calcium Oxide Treatment of Dry and Modified Wet Distillers Grains with Solubles on Economics, Feed Intake Pattern, and Growth and Carcass Performance of Feedlot Steers

Abstract Text: Objectives of this study were to determine the interaction of feeding dry (DDGS) or modified wet (MDGS) distillers grains with solubles with or without CaO treatment to steers on growth performance, feed intake patterns, economics of gain, and USDA carcass grades. Steers (n=139; initial BW=336±75 kg) were blocked by BW and allotted to 20 pens. Pens were randomly assigned to 1 of 4 dietary treatments arranged in a 2×2 factorial: (1) 50% DDGS untreated, (2) 48.8% DDGS treated with 1.2% CaO, (3) 50% MDGS untreated, or (4) 48.8% MDGS treated with 1.2% CaO. The remainder of the diets were husklage, dry rolled corn, and vitamin and mineral supplement. There was no interaction (P ≥ 0.14) of distillers grains (DGS) type and CaO treatment on DMI, ADG, final BW, or USDA carcass grades. However, steers fed CaO treated DGS ate 6.6% less (P < 0.01) DM. Because CaO treatment decreased DMI without affecting (P = 0.66) ADG, steers fed CaO treated DGS had a 5% increase (P < 0.01) in G:F. Cattle fed DDGS tended (P = 0.06) to increase DMI; however, this tendency did not equate to a difference (P = 0.56) in G:F. There was an interaction (P < 0.01) of CaO treatment and DGS type on pattern of intake. Treatment with CaO reduced the percentage of meals consumed from 0 to 3h post feeding in cattle fed DDGS; however, there was no effect on cattle fed MDGS. Steers fed MDGS spent less (P = 0.05) time at the bunk and ate smaller (P < 0.01) meals, but consumed more (P = 0.01) meals per day when compared to steers fed DDGS. Steers fed CaO treated DGS ate a similar number of meals (P = 0.36), but ate smaller meals (P < 0.01) than steers fed 0% CaO. While CaO treatment increased the ration cost $3.50 per metric ton of DM, improved G:F in steers fed CaO treated DGS resulted in a 6% decrease (P < 0.01) in cost of gain. Furthermore, feeding MDGS reduced (P < 0.01) cost of gain by $0.09 per kg and total feed cost by $25.78. Therefore, this trial supports previous research that suggests feeding MDGS can be advantageous when compared to feeding DDGS and provides new information that treating DGS with CaO can further reduce cost of gain and improve feed efficiency.

Keywords: beef cattle, calcium oxide, distillers grains