Effects of feeding wheat middlings on production, digestibility, ruminal fermentation and carcass characteristics in beef cattle

Studies were conducted to compare the feed value of wheat middlings (WM) to cereal grains in rations with varying concentrate to roughage levels. In two separate studies, weaned heifers and steers were fed corn silage/alfalfa hay-based growing diets where the concentrate source was either a control diet consisting of rolled barley (heifers) or rolled corn (steers) versus WM, over an 84-d period. In a 107-d study, finishing steers were fed treatments that consisted of rolled corn (C) plus either 35% wheat middlings (WM35) or 50% wheat middlings (WM50). A single cross-over designed digestibility study was also conducted utilizing four cannulated yearling heifers fed either a corn or WM50 diet from the finishing steer study. Results from the heifer and growing and finishing steer studies showed that average daily gain (ADG), dry matter intake (DMI) and feed efficience (FE) were not affected (P > 0.05) by feeding treatment. Carcass characteristics, including hot carcass weight, ribeye area, backfat, yield, quality grade and curability were also unaffected (P > 0.05) by feed treatment. Results from the digestibility studies indicated total volatile fatty acids (VFA) were increased (P = 0.023) in the WM diet, with acetate lower (P = 0.0003) than the C group, and pH levels of 5.81 and 5.55 for the C and WM treatments respectively (P = 0.011). Dry matter and ADF digestibilities were not affected (P > 0.05) by feed treatment. It is concluded from these studies that WM can be fed to growing beef heifers and steers as an alternative to more traditional concentrate sources such as corn or barley. Wheat middlings could replace up to 50% of the concentrate in a finishing ration. However, certain ruminal fermentation characteristics such as pH, acetate: propionate ratio and total volatile fatty acids may be altered, which could affect performance over an extended feeding period.