title: Comparative feeding value of distillers dried grains plus solubles as a partial replacement for steam-flaked corn in diets for calf-fed Holstein steers: characteristics of digestion, growth performance, and dietary energetics.
abstract: Two experiments were conducted to examine the effect of level of dried distillers grains plus solubles (DDGS) supplementation (0, 10, 20, and 30%; DM basis), replacing steam-flaked (SF) corn in finishing diets, on characteristics of digestion (Exp. 1) and growth performance (Exp. 2) in calf-fed Holstein steers. In Exp.1, 4 cannulated Holstein steers (349 ± 12 kg) were used to evaluate treatment effects on characteristics of digestion. Ruminal NDF digestion tended to increase (quadratic effect, P = 0.09) and ruminal OM digestion decreased (linear effect, P = 0.01) with DDGS substitution. There were no treatment effects on duodenal flow of microbial N (MN). Substitution with DDGS increased (linear effect, P < 0.01) N flow to the small intestine. The undegradable intake protein (UIP) value of DDGS was 35%. Postruminal digestion of OM (linear effect, P = 0.04) and fatty acids (linear effect, P = 0.03) and total tract digestion of OM and GE decreased (linear effect, P < 0.03) with increasing level of DDGS substitution. Substitution with DDGS did not affect (P = 0.80) ruminal pH but increased (linear effect, P = 0.01) acetate:propionate molar ratio. In Exp.2, 144 Holsteins steer (112 ± 6 kg) were used in a 305-d trial to evaluate treatment effects on growth performance and carcass characteristics. During the initial 126 d, DDGS substitution increased ADG (linear effect, P = 0.03), G:F (quadratic effect, P = 0.03), and dietary NE (quadratic effect, P = 0.02), maximal for both at 20% DDGS inclusion rate. Based on estimated indispensable AA supply to the small intestine as a percentage of requirements during the initial 126-d period, histidine was first limiting followed by methionine. During the final 179-d period and overall (305-d feeding period), treatment effects on ADG and G:F were small (P ≥ 0.22). Compared with the other treatments, HCW was greater (3.4; P = 0.03) at the 20% level of DDGS substitution. The NE value for DDGS in SF corn-based diets for the calf-fed Holstein are consistent with current tabular standards. Extra-caloric value of DDGS as a metabolizable AA source is apparent during the initial growing phase. The UIP value of DDGS used in this study (35%) was considerably less than current tabular estimates (52%; NRC, 2000).
authors: Department of Animal Science, University of California, Davis 95616, USA.
authors: R
authors: R
authors: Carrasco
authors: A A
authors: AA
authors: Arrizon
authors: A
authors: A
authors: Plascencia
authors: N G
authors: NG
authors: Torrentera
authors: R A
authors: RA
authors: Zinn
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology; D000818:Animals; D002417:Cattle / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D004032:Diet / Q000379:methods / Q000662:veterinary*; D004063:Digestion / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005227:Fatty Acids / Q000032:analysis; D005766:Gastrointestinal Contents / Q000737:chemistry / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D008297:Male; D012417:Rumen / Q000502:physiology; D003313:Zea mays
chemical_list: D000596:Amino Acids; D005227:Fatty Acids