Effect of different inclusion rates of Fermenten on performance, carcass characteristics, and total tract digestibility of growing Angus crossbred steers

Abstract Text: The objective of this study was to assess the effects of including increasing inclusion rates of the feed additive Fermenten (FER; Church & Dwight Co., Inc., Princeton, NJ, USA) on performance, carcass characteristics, and total tract digestibility of growing steers. Eighty-one Angus crossbred steers (189 ± 22 kg) were used in a generalized randomized block design. Initial BW was used as the blocking factor. Steers were randomly assigned to one of 3 treatments: 0, 2, and 4% FER in the diet DM of a backgrounding diet comprised of peanut hulls, corn gluten feed, soybean hulls and soybean meal. Diets were formulated to contain equal amounts of RDP and energy (6.5% RDP, 70.6% TDN, DM basis). From d 0 to 56, steers were housed in 9 pens (9 steers/pen), with ad libitum access to diets. Individual intake was recorded using a GrowSafe feed intake monitoring system. From d 57 to d 112, steers were moved to a paddock with ad libitum access to a basal diet common to all animals, without FER, to assess potential residual effects of FER feeding. Every 14 d, unshrunk BW was recorded, and blood samples were collected to measure glucose, blood urea nitrogen (BUN) and NEFA in serum. Every 28 d carcass ultrasound was performed to assess fat thickness (FT) and longissimus dorsi area (LDA). Apparent total tract digestibility of nutrients was measured in a subsample of 27 steers (9/treatment) using indigestible NDF as a marker. Data were analyzed as a generalized randomized block design, using steer as the experimental unit. The model included the random effect of steer, and fixed effect of treatment, block and pen. Steers fed 4% FER had decreased (P < 0.05) DMI, BW (d 56), ADG (d 0 to 56), and G:F compared with 0 and 2% FER. No differences were observed (P ≥ 0.05) in blood parameters, LDA, FT, DMI as a percentage of BW, final BW at d 112, and ADG  from d 56 to 112. The inclusion of 4% FER increased the digestibility of DM, OM, NDF, and ADF compared with 2, and 0% FER (P ≤ 0.05). Inclusion of Fermenten above 2% of the diet DM may reduce DMI, thus decreasing the performance and feed efficiency of growing Angus crossbred steers.

Keywords: Fermenten, beef cattle, performance