|Parker, David - WEST TEXAS A&M UNIVERSITY|
Submitted to: American Society of Animal Science Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: February 22, 2006
Publication Date: July 10, 2006
Citation: Archibeque, S.L., Miller, D.N., Parker, D.B., Freetly, H.C., Ferrell, C.L. 2006. Effects of feeding steam-rolled corn in lieu of dry-rolled corn on the odor of finishing beef steer manure [abstract]. Journal of Animal Science 84(Suppl. 1):154-155. Technical Abstract: Fecal starch is the major source of odorous compounds produced in the manure of steers fed typical finishing diets. We hypothesized that feeding steam-rolled corn (SR) in lieu of dry-rolled corn (DR) in finishing diets would increase starch digestibility and thus reduce odor production from manure. Eight steers (318 +/- 15 kg) were used in a nutrient balance trial with a crossover design and fed either a DR- or SR-based finishing diet. Feces collected during the first day of each balance trial were analyzed for volatile organic compound emission and olfactometry by a trained sensory panel. There was no difference (P = 0.96) in starch intake between steers fed DR (4293 g/d) or SR (4283 g/d) diets, but fecal starch of steers fed SR (253 g/d) was lower (P < 0.01) than that of steers fed DR (490 g/d). Although N intake was greater (P < 0.01) in steers fed DR (137 g/d) than those fed SR (110 g/d), there was no difference (P = 0.99) in retained N. Although starch concentrations of feces collected during the balance trial were different (P < 0.01), there was no difference (P = 0.79) in fecal starch concentration used for odor detection. There was no difference in odor intensity (P = 0.28), hedonic tone (P = 0.29), or total ionizable current (a measure of total organic volatilization, P = 0.24) of fresh feces from steers fed DR or SR. However, fecal odor of steers fed SR tended (P = 0.09) to have a higher panel detection threshold and a greater (P = 0.03) volatilization of branched chain VFA than that of steers fed DR. Total ionizable current was correlated to both odor intensity (r = 0.56, P = 0.02) and hedonic tone (r = -0.52, P = 0.04). Differences between the fecal starch concentrations during the balance trial and the odor assessment may have contributed to the lack of difference in odor detection.