Total and Water Soluble Phosphorus Content of Feedlot Cattle Feces and Manure

The percentage of feedlot feces and manure P that is water soluble was 41% (not accounting for additional soluble P from urine) and 24% respectively. The interaction of feces and urine with minerals and metals reduced the water solubility of P in feedlot manure relative to feces. Increasing dietary P level increased manure P concentration and water solubility of manure. Manure P from cattle fed feedlot diets containing 0.30% to 0.50% P was 28% water soluble P. The water solubility of P in feedlot feces and manure is an indicator of the potential for P runoff from feedlots and fields receiving manure

Effects of Backgrounding and Growing Programs on Beef Carcass Quality and Yield

Clearly, the future of the beef cattle industry in the United States depends on the quality of the product. The majority of calves are born in the spring; therefore, to have a consistent supply of feeders entering feedlots and to take advantage of forages, a variety of stocker programs exist. Cattle enter the feedlot at varying weights and ages and from different nutritional backgrounds, and this variation could produce differences in carcass quality. The economically important measures of carcass quality are yield grade and quality grade. They are directly related: as cattle fatten in the feedlot, both quality grade and yield grade increase. Because cattle are commercially fed to fat-constant end points, it is logical to make comparisons at equal fat end points. Then, marbling (percentage Choice) becomes the primary quality criterion. We analyzed data from 534 cattle serially slaughtered and found that the percentage grading Choice increased 12 ± 1 percentage units for each 1-mm increase in rib fat. Marbling score increased 30 units (200 = slight 00) for each 1-mm increase in fat. To determine the effect of rate of winter gain on carcass quality, 372 calves over 5 yr were wintered at .23 or .61 kg/d gain. When adjusted to equal rib fat after summer grazing and finishing, there was no difference in quality grade. To test the effect of summer gain on carcass quality, 418 calves over 7 yr were followed through the feedlot after gaining .57 or .84 kg/d on grass. When compared at equal rib fat, there was no difference in quality grade. Shear force values and consumer taste panels were used to evaluate steaks from 90 cattle from calf-fed and yearling production systems. Calf-feds were 14 mo of age at slaughter and yearlings were 19 or 21 mo. Each group was serially slaughtered. There was no effect of an additional .39 cm of rib fat on shear force, juiciness, tenderness, flavor, or overall palatability. Calf-feds were significantly more tender than yearlings, but the risk of an undesirable steak from yearlings was \u3c .2% based on shear force and \u3c 2.8% based on the consumer taste panel. If cattle are fed to a common rib fat end point, and within the range of rates of winter and summer gains reported herein, we conclude that the backgrounding program has little or no effect on marbling or carcass quality grade

Cattle CODE: An Economic Model for Determining Byproduct Returns for Feedlot Cattle

Cattle CODE — Coproduct Optimizer Decision Evaluator — is a model developed to predict performance and economic returns when byproducts are fed to finishing cattle. Four scenarios were evaluated to illustrate how the model works and to show sensitivity to corn price and distance from the ethanol plant, which resulted in positive returns for feeding WDGS, Sweet Bran, or DDGS up to 50% of diet DM and under 100 miles distance from the ethanol plant to the feedlot

Cattle CODE: An Economic Model for Determining Byproduct Returns for Feedlot Cattle

Cattle CODE — Coproduct Optimizer Decision Evaluator — is a model developed to predict performance and economic returns when byproducts are fed to finishing cattle. Four scenarios were evaluated to illustrate how the model works and to show sensitivity to corn price and distance from the ethanol plant, which resulted in positive returns for feeding WDGS, Sweet Bran, or DDGS up to 50% of diet DM and under 100 miles distance from the ethanol plant to the feedlot

Feedlot Surface Conditions and Ammonia Emissions

Moisture and urine were applied to a feedlot surface in a 2x2 factorial design. Forced-air wind tunnels were used to determine differences in the net flux of ammonia (NH3) being volatilized. Surface DM, pH and surface temperature were all analyzed within each treatment to determine effect on NH3 net flux. No effects of urine were detected. There were differences detected due to moisture and moisture*time with the dry plots releasing significantly more NH3

Using a Modified \u3ci\u3eIn-Vitro\u3c/i\u3e Procedure to Measure Corn Bran Buoyancy

An in vitro procedure was modified to estimate rumen buoyancy of corn bran and fiber types. Inoculum was obtained from two beef heifers and mixed with McDougall’s buffer then distributed to the in vitro tubes for 30 hours incubation at 100 °F. Fibrous material formed a matte layer which was measured to describe buoyancy. Tubes contained 6g of a feedlot-type diet with 7.5% fiber type (alfalfa hay, grass hay, corn silage, or corn stalks), with no replacement or 25% replacement of the remaining corn with corn bran. Buoyancy declined over time. Alfalfa hay had the most positive effect on buoyancy of corn bran. This new method offers promise for describing rumen buoyancy

Comparative Effects of the Sorghum \u3ci\u3ebmr\u3c/i\u3e-6 and \u3ci\u3ebmr\u3c/i\u3e-12 Genes: II. Grain Yield, Stover Yield, and Stover Quality in Grain Sorghum

Nearly 3 million hectares of grain sorghum [Sorghum bicolor (L). Moench] are harvested in the USA each year. It may be possible to add value to crop and animal systems by enhancing the digestibility of the stover residue by the use of brown midrib (bmr) genes if grain can be maintained. The objectives of this study were to evaluate the effect of bmr-6 and bmr-12 genes on grain yield of sorghum and to evaluate the effect of the bmr genes on stover yield and quality in these genetic backgrounds: ‘Wheatland’, ‘Redlan’, RTx430, Tx623, Tx630, Tx631, and the hybrid AWheatland X RTx430. Plant height, maturity, grain yield and test weight, stover neutral detergent fiber NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and in vitro NDF digestibility (IVNDFD) were measured in split-plot experiments replicated four times in each of four environments with lines being whole-plots and genotypes being subplots. Brown midrib genes reduced grain yield and residue yield in the lines; however, yield reduction was not observed in the bmr-12 AWheatland X RTx430 hybrid. The bmr-12 near-isolines generally had lowest stover lignin content and highest fiber digestibility, bmr-6 was intermediate, and wild-type counterparts had highest lignin content and lowest fiber digestibility. When all data are considered, the bmr-12 gene appears superior to the bmr-6 gene in terms of potentially adding value to the stover of grain sorghum for use in crop/animal systems. The variable expression of bmr-12 and bmr-6 in different lines indicates that selection of compatible genetic backgrounds will be critical in determining the realized impact on value

Feedlot Surface Conditions and Ammonia Emissions

Moisture and urine were applied to a feedlot surface in a 2x2 factorial design. Forced-air wind tunnels were used to determine differences in the net flux of ammonia (NH3) being volatilized. Surface DM, pH and surface temperature were all analyzed within each treatment to determine effect on NH3 net flux. No effects of urine were detected. There were differences detected due to moisture and moisture*time with the dry plots releasing significantly more NH3

Registration of \u27Manska\u27 Pubescent Intermediate Wheatgrass

\u27MANSKA\u27 pubescent intermediate wheatgrass [Thinopyrum intermedium subsp. barbulatum (Schur) Barkw. & Dewey] (Reg. no. CV-21, PI 562527) was tested as Mandan 12781 and released 16 April 1992 by the USDA-ARS in cooperation with the USDA-SCS; the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska; and the North Agricultural Experiment Station