Project Number: 6209-31630-002-27
Project Type: Specific Cooperative Agreement

Start Date: Sep 15, 2008
End Date: Sep 30, 2010

Objective:
Determine the effects of proportions of steam-flaked corn and whole shelled corn in the basal grain on in vitro dry matter disappearance, in vitro gas production, and in vitro hydrogen sulfide production in substrates containing 0, 15, and 30% sorghum-based and corn-based wet distiller's grains.

Approach:
In vitro dry matter (DM) disappearance (IVDMD) will be measured using standard procedures (Galyean, 1997). Duplicate samples (0.5 g; described below) will be incubated in a 3:1 ratio of McDougall's buffer to ruminal fluid. A computerized gas-production system with automated pressure transducers (Ankom Technology, Macedon, NY) will be used to measure 24 hour gas production rates from 0.7 g (DM basis) of the same substrates used for IVDMD analyses along with McDougall¿s buffer and ruminal fluid (3:1 ratio). To measure hydrogen sulfide production, duplicate, 125-mL serum vials containing 0.7 g of substrate will be inoculated with buffer and ruminal fluid. Total gas produced will be measured via a water manometer system, and samples of gas will be collected from the sealed vials and analyzed for hydrogen sulfide concentration (Kung et al., 2000). Treatments will consist of the following dietary combinations added directly to each vial at the start of the incubation process: Sorghum Wet Distiller's Grain (SWDG) Experiment 1 1. 100% SFC as the basal grain in the substrate. 2. 75% SFC:25% WSC as the basal grain in the substrate. 3. 50% SFC:50% WSC as the basal grain in the substrate. 4. 100% SFC as the basal grain in the substrate with 15% SWDG. 5. 75% SFC:25% WSC as the basal grain with 15% SWDG. 6. 50% SFC:50% WSC as the basal grain with 15% SDWG. Sorghum Wet Distiller's Grain Experiment 2 1. 100% SFC as the basal grain in the substrate. 2. 75% SFC:25% WSC as the basal grain in the substrate. 3. 50% SFC:50% WSC as the basal grain in the substrate. 4. 100% SFC as the basal grain in the substrate with 30% SWDG. 5. 75% SFC:25% WSC as the basal grain with 30% SWDG. 6. 50% SFC:50% WSC as the basal grain with 30% SDWG. Corn Wet Distiller's Grain (CWDG) Experiment 3 1. 100% SFC as the basal grain in the substrate. 2. 75% SFC:25% WSC as the basal grain in the substrate. 3. 50% SFC:50% WSC as the basal grain in the substrate. 4. 100% SFC as the basal grain in the substrate with 15% CWDG. 5. 75% SFC:25% WSC as the basal grain with 15% CWDG. 6. 50% SFC:50% WSC as the basal grain with 15% CDWG. Corn Wet Distiller's Grain Experiment 4 1. 100% SFC) as the basal grain in the substrate. 2. 75% SFC:25% WSC as the basal grain in the substrate. 3. 50% SFC:50% WSC as the basal grain in the substrate. 4. 100% SFC as the basal grain in the substrate with 30% CWDG. 5. 75% SFC:25% WSC as the basal grain with 30% CWDG 6. 50% SFC:50% WSC as the basal grain with 30% CDWG Each experiment will be analyzed as a randomized complete block design using the Mixed procedure of SAS (SAS Inst., Inc., Cary, NC). The separate ¿runs¿ will be considered as random blocks in the analysis. Means will be separated by pre-planned orthogonal contrasts.