Project Number: 3625-31000-003-11
Project Type: Reimbursable

Start Date: Jun 15, 2008
End Date: Jun 15, 2009

Objective:
Objectives of the proposed research are: (1) evaluate the ability of commercially available enzyme preparations to improve the apparent dry matter (DM), lipid (EE), phosphorus (P), nitrogen (N), energy (E), and fiber (NDF and ADF) digestibility of diets containing 30% corn dried distillers grains with solubles (DDGS); and (2) evaluate potential interactive effects between enzymes and mechanical processing (extrusion) on nutrient digestibility. Each of the above objectives will be conducted in nursery (10 kg) and finishing (90 kg) pigs due to potential age differences on enzyme efficacy. Following the completion of the first two objectives, a follow-up study is proposed (Year 2) to evaluate the effect of enzyme addition to a diet containing DDGS on overall wean-to-finish pig performance and carcass characteristics.

Approach:
Year 1 - Objective 1: Nine commercially available enzyme preparations will be added to nursery and finishing diets containing 30% DDGS to evaluate their impact on apparent DM, EE, P, N, E, NDF, and ADF digestibility. This will be accomplished by feeding a minimum of 8 individually penned pigs per treatment diets containing the recommended level of enzyme preparation. Diets will contain 0.5% titanium dioxide as an inert marker to determine digestibility coefficients. Pigs will be fed diets for 4 wk with fecal samples obtained at the end of wk-2 and wk-4 to determine if there is a time effect, within each phase of growth, on nutrient digestibility. Pigs and feeders will be weighed to determine impact of dietary treatment on growth, feed intake, and feed efficiency. Data will be analyzed using the Proc Mixed procedures of SAS with the main effects of dietary treatment on the dependent variables of apparent DM, EE, N, E, NDF, ADF, and growth performance using the individual pig as the experimental unit in a completely randomized design. Year 1-Objective 2: From the enzyme products evaluated in Objective 1, the two enzyme products showing the most improvement on energy (or fiber) digestibility will be selected and evaluated for potential interactive effects with feed processing (extrusion) using a 2 x 3 factorial arrangement of treatments. If no improvement is noted by any enzyme product, two enzymes with different reported enzymatic activities will be selected for further testing in this objective. Pigs will be managed as described in Objective 1. Data will be statistically analyzed using the Proc Mixed procedures of SAS with the main effects of dietary treatment on the dependent variables of apparent DM, EE, P, N, E, NDF, and ADF, using the individual pig as the experimental unit with a factorial arrangement of treatments within a completely randomized design. Year 2 - Objective 1: Following the results obtained in Year 1-Objective 2, one or two enzymes will be utilized for the growth performance study. Experimental diets will consist of enzyme use (¿ or +) in combination with diets containing DDGS (10, 20, 30, and 40% in Phase 1 thorough 4, respectively). Four hundred and eighty 18-d old crossbred pigs will be randomly allotted to 60 pens in a wean-to-finish facility at the University of MN Swine Research Center at Waseca, MN. There will be 8 pigs per pen and 10 pens per dietary treatment. Pigs will be offered their experimental diets from d 18 until market weight of 120 kg live weight. Feed intake and pig weight will be determined at the end of every phase. Pigs will be shipped to a commercial slaughter plant (Hormel Foods, Austin, MN) for measurement of carcass characteristics.