Reducing Particle Size Enhances Chemical Treatment in Finishing Diets

Three hundred-sixty calf-fed steers were fed either treated or untreated corn stover that was previously ground through a 1-in or 3–in screen. Treated stover diets improved ADG and F:G compared to untreated. Reducing particle size improved ADG and F:G but did not influence DMI. Compared to a control diet with 5% roughage and 15 percentage units more corn, diets with 20% treated corn stover had similar F:G, ADG, DMI, and carcass quality. Up to 15% additional corn can be replaced with treated corn stover when diets contain wet distillers grains, and may be further enhanced by reducing particle size before chemical treatment

Reducing Particle Size Enhances Chemical Treatment in Finishing Diets

Three hundred-sixty calf-fed steers were fed either treated or untreated corn stover that was previously ground through a 1-in or 3–in screen. Treated stover diets improved ADG and F:G compared to untreated. Reducing particle size improved ADG and F:G but did not influence DMI. Compared to a control diet with 5% roughage and 15 percentage units more corn, diets with 20% treated corn stover had similar F:G, ADG, DMI, and carcass quality. Up to 15% additional corn can be replaced with treated corn stover when diets contain wet distillers grains, and may be further enhanced by reducing particle size before chemical treatment

Factors affecting efficiency of net ruminal microbial protein synthesis in cattle

Two experiments were conducted to examine factors that affect nutrient digestion and microbial protein synthesis in cattle. In the first study, four cannulated (rumen, proximal duodenum, terminal ileum) steers were used in a 4 $\times$ 4 Latin square design experiment. Steers were fed corn/corn silage (low forage) or alfalfa hay/corn silage (high forage) diets twice or 12 times daily. Site of OM digestion shifted from the rumen to the small intestine and total tract OM digestion was increased when steers were fed the low forage diet. Nonbacterial N flows at the duodenum increased when steers were fed the low forage diet and when fed 12 times daily. Results of this study suggest that energy level of the diet can impact on site of nutrient digestion and supply of nutrients at different sites within the digestive tract. However, feeding frequency had minimal impact on digestive kinetics.In a concurrent project, effects of main treatment factors and bacterial harvesting techniques on bacterial composition were investigated. Whole ruminal contents were collected from steers and fluid- and particle-associated bacteria were obtained. Energy level, feeding frequency and pre-harvesting freezing had only minor effects on composition of harvested bacteria but differences were observed in fluid vs particle-associated or mixed populations of ruminal bacteria.In the second study, four multiple-cannulated steers were used in a 4 $\times$ 4 Latin square design to examine effects of forage:concentrate ratio and ruminally degradable protein supply on microbial N Kinetics and net protein synthesis. Steers were fed ammoniated corn cob (high forage) or corn cob/ground corn/cornstarch (low forage) diets supplemented with soybean meal (SBM) or a combination of corn gluten meal and blood meal (CB). Efficiency of bacterial CF synthesis (E\sb{\rm MCP}) decreased when the low forage diet was fed but duodenal bacterial N flows were unaffected by energy level. Feeding SBM vs CB increased E\sb{\rm MCP} and flow of bacterial N to the small intestine. It was concluded that inclusion of a ruminally degradable protein in the diet may synchronize release of nutrients from proteolysis with release of energy from fermentation.U of I OnlyETDs are only available to UIUC Users without author permissio

Evaluation of Rumen Metabolism and Digestibility when Treated Crop Residues are Fed in Cattle Finishing Diets

A metabolism trial was conducted to evaluate rumen pH, digestibility, and ruminal VFA concentrations of steers fed 25% CaO treated or untreated cobs, wheat straw, and corn stover. Treated diets had greater digestibility of DM, OM, and NDF compared to untreated diets. Substituting 15 percentage units of corn and 10% roughage with 25 percentage units of 5% CaO treated cobs, wheat straw, or corn stover resulted in similar DM digestibility, rumen pH and VFA concentrations

Digestibility of Crop Residues After Chemical Treatment and Anaerobic Storage

Two experiments were conducted to evaluate factors affecting crop residue digestibility. Corn stover, corn cobs, and wheat straw were alkaline treated at low (35%) or high (50%) moisture and then anaerobically stored at 30 °C or 40 °C. Chemical treatment increased in vitro DM digestibility of all residues by 14 to 21 percentage units (35% to 62% improvement). Samples stored at 50% DM and 40oC were most digestible. Cobs were inherently more digestible than straw or corn stalks. Percentage of total improvement in DM digestibility by optimizing DM, ambient temperature, and chemical treatment was: stalks, 43%; wheat straw, 38%;, and cobs, 34%. Digestibility of low quality crop residues can be improved markedly by chemical treatment

Varying Proportions and Amounts of Distillers Grains and Alkaline-Treated Forage as Substitutes for Corn Grain in Finishing Cattle Diets

A 124-day individually fed finishing study was conducted to evaluate corn grain replacement by distillers grain and 5% CaO treated crop residue. Dietary treatments were two ratios (2:1 or 3:1) of modified distillers grains and treated crop residues (DGCR), two types of treated crop residue (corn stover or wheat straw) at 3:1 ratio, and then with three dry rolled corn (DRC) levels (10%, 25%, 40%; DM basis). Steers fed diets containing as little as 25% corn and 3:1 ratios of distillers grains and CaO treated crop residues can achieve similar F:G compared with cattle fed diets containing 5% roughage and 56% corn

Chemical Treatment of Low-quality Forages to Replace Corn in Cattle Finishing Diets

A finishing experiment evaluated substitution of corn with crop residues in diets containing wet distillers grains. Corn stover, corn cobs, and wheat straw were alkaline treated at 50% moisture or fed without chemical treatment at 20% inclusion. Chemical treatment improved performance compared to untreated. Compared to control (10% roughage), treated diets had similar performance and carcass merit. Economic analysis revealed $6.46,$21.42, and $36.30 average profit per head advantage for diets containing treated residues relative to control when corn was priced at$3.00, $4.50, and$6.00 per bushel. Feeding chemically treated crop residues and wet distillers grains is a cost-effective strategy for replacing corn in feedlot diets without compromising performance or carcass quality

Effect of Feeding Greater Amounts of Calcium Oxide Treated Corn Stover and Micro-Aid® on Performance and Nutrient Mass Balance

Feedlot performance and mass balance were evaluated on steers fed either 5% untreated corn stover (CON), 20% untreated corn stover (NONTRT), or 20% calcium oxide (CaO) treated corn stover (TRT) when fed with or without saponins (Micro-Aid) in a 3x2 factorial. In both WINTER and SUMMER experiments, ADG, F:G and HCW were improved (P \u3c 0.01) in CON and TRT fed steers compared to NONTRT fed steers. Micro-Aid fed steers had slightly greater ADG and DMI in the SUMMER. Manure% nitrogen (N) was greatest when NONTRT and TRT were fed compared to steers on CON diet. However, neither diet nor Micro-Aid influenced manure N amounts or N losses across both seasons