Strip loins and eye of rounds from steers genotyped as having zero, one, or two copies of the inactive myostatin (IM) mutation were obtained. Steaks for nutrient analysis were cut and frozen and steaks for tenderness were aged for 14 days and cooked fresh, never frozen. Meat from cattle with one copy and two copies were more tender than zero copy cattle for eye of round steaks. Homozygous IM cattle had less overall fat content and calories than homozygous normal cattle.

In 2006, the USDA Natural Resources Conservation Service (NRCS) Conservation Innovation Grant program funded a project to develop the infrastructure for the systematic development and implementation of the USDA-NRCS Feed Management (FM) Conservation Practice Standard 592 (CPS 592). The overall goal of CPS 592 is to encourage adoption of FM practices that can have a positive impact on soil, water, and air quality. Implementation documents, templates, decision aid tools, and supporting fact sheets were developed for the species of beef, dairy, poultry, and swine. Specific objectives of the project were to 1) assist USDA-NRCS staff and agricultural professionals to increase their understanding of FM and its impacts on environmental sustainability of livestock and poultry operations, 2) improve the proficiency of agricultural professionals in the development and implementation of a FM plan as part of a Comprehensive Nutrient Management Plan, 3) provide the American Registry of Professional Animal Scientists with certification exams, and 4) provide methodology on how to assess the financial implications of different ration strategies on whole-farm nutrient balance and economics of use of manure nutrients at agronomic rates. Implementation of CPS 592 is described for the states of California, Maryland, Pennsylvania, and Wisconsin.

Nitrogen losses from open beef feedlots are a concern. Methods that decrease volatilization losses will lead to greater manure N, which is likely to be beneficial in open lot beef operations. Twelve or more pens were dedicated to N research whereby N intake, retention, and excretion were quantified and a mass balance conducted using manure, runoff, soil balance, and loss quantities. The objective was to decrease N volatilization losses or increase manure N or both. Dietary CP affects N excretion and N volatilization losses. Four experiments across 2 yr compared industry average CP (13%) to diets that were phase-fed to not exceed protein requirements (12.1 to 10.9%). Phase-fed cattle excreted 12 to 21% less N (P < 0.01), and N volatilization losses were reduced 15 to 33% (P < 0.01). In 2 other experiments, phase-fed diets were formulated to recycle undegradable intake protein. Steer G:F was similar (P = 0.18) or improved (P = 0.09), whereas N excretion and N volatilization losses tended to be reduced (P < 0.11) and N in manure was not affected (P > 0.35) compared with cattle fed 13% CP. Feeding less protein did not affect manure N, indicating manure N from open lots is related to other factors. A series of experiments evaluated increasing OM on the pen surface to increase N in manure. Feeding less digestible diets using fiber increased manure N (P < 0.01) and decreased (P < 0.10) N volatilization losses in 2 experiments conducted from November to May, but did not affect (P > 0.30) manure N or volatilization losses during 2 summer experiments. Adding bedding (i.e., OM) increased manure N in the winter as well. Another method evaluated was increasing pen cleaning frequency, which decreased N volatilization losses by 19 to 44% and increased manure N by 26 to 41% across 3 experiments. Other methods, such as acidifying manure by manipulating dietary cation anion difference, clinoptilite zeolite clay addition, and feeding different amounts of by-products had variable impacts on N volatilization losses. No treatments markedly affected runoff N, which is <5% of excreted N. Dietary protein affects N volatilization losses but not manure N. Other factors, such as OM on the pen surface, affect manure N. Cleaning manure frequently, which decreases exposure of manure N to air, decreases volatilization losses. Treatments should be evaluated across seasons due to seasonal effects.

‘Warrior’ (Reg. No. CV‐252, PI 655523), ‘Scout’ (Reg. No. CV‐253, PI 655524), and ‘Chief’ (Reg. No. CV‐254, PI 655525) indiangrass [Sorghastrum nutans (L.)] Nash were developed for improved yield and forage digestibility by USDA‐ARS and the University of Nebraska for use in the central Great Plains and the Midwest USA. Warrior was tested as Oto C3 and was developed by means of both half‐sib family selection and restricted, recurrent phenotypic selection (RRPS). Scout and Chief which were tested as NE54 C2 and Holt × Oto Early C2, respectively, were developed by RRPS. Warrior is adapted to USDA Plant Hardiness Zone (HZ) 5 and the upper part of HZ 6 in the Great Plains and Midwest. It produces forage with high in vitro dry matter digestibility (IVDMD) that results in improved animal gains when utilized by beef cattle in well managed grazing systems in regions where it is adapted. Scout is adapted to HZ 5 in the Great Plains and Midwest, USA. It produces significantly greater forage yields than other adapted indiangrass cultivars when grown for hay in the western part of its adaptation region. Chief is adapted to HZ 4 and the upper half of HZ 5. It produces significantly greater forage yields than the other available HZ 4 cultivars. Warrior, Scout, and Chief represent the second generation of indiangrass cultivars developed for use in production agriculture. In the regions where they are adapted, these cultivars can be used in pure stands or in multispecies mixtures with other grasses.

Two experiments were conducted to determine the effect of corn processing method and corn wet distillers grains plus solubles (WDGS) level on steer performance and metabolism. In Exp. 1, 480 crossbred steer calves (314 +/- 18 kg of BW) were used in a finishing experiment with a randomized complete block design and a 3 x 4 treatment structure. Diets were based on dry-rolled (DRC), high-moisture (HMC), or steam-flaked corn (SFC) with increasing levels of WDGS (0, 15, 27.5, or 40%; DM basis). A corn processing x WDGS level interaction (P < 0.01) was observed for ADG and G:F. Average daily gain and G:F increased linearly (P < 0.01) in steers fed DRC; ADG increased quadratically (P = 0.04) and G:F increased linearly (P = 0.02) in steers fed HMC; and ADG decreased quadratically (P = 0.02) with no change in G:F (P = 0.52) in steers fed SFC as WDGS increased. In Exp. 2, 7 ruminally fistulated steers (440 +/- 41 kg of BW) were used in a 6-period crossover design with 3 x 2 factorial treatment structure. Diets were the same as those fed in Exp. 1, except they contained only 2 levels of WDGS (0 or 40% of diet DM). Total tract starch digestibility was greater (P < 0.01) for steers fed SFC than for steers fed DRC or HMC. Minimum ruminal pH was less (P < 0.01) for steers fed SFC than for steers fed HMC or DRC. Variance of ruminal pH was different among all 3 processing methods with DRC < HMC < SFC (P < 0.10). In situ 22-h DM digestibility of DRC and HMC and starch digestibility of DRC were greater (P < 0.10) in steers fed DRC compared with steers fed HMC or SFC. Steers fed 0% WDGS had less (P < or = 0.02) intake of DM, OM, NDF, and ether extract compared with steers fed 40% WDGS. Total tract digestibility of DM and OM was greater (P < or = 0.08) and digestibility of ether extract tended (P = 0.11) to be less for steers fed 0% WDGS compared with steers fed 40% WDGS. Maximum ruminal pH and pH variance were greater (P < or = 0.08) in steers fed 0% WDGS. A corn processing x WDGS level interaction (P = 0.09) was observed for ruminal acetate to propionate ratio (A:P). Within diets containing 0% WDGS, A:P in steers fed SFC was less (P < or = 0.08). In diets containing 40% WDGS, A:P was similar between processing methods and not different from the SFC with 0% WDGS. The corn processing x WDGS level interaction observed in the finishing experiment may be due to the decreased ruminal A:P in DRC and HMC diets with 40% WDGS.

to have higher ruminal passage rates of starch. Total molar proportion of volatile fatty acid tended to be greater for diets including grain comprised of oury endosperm. While ruminal pH was unaffected by treatments, diets consisting of inty endosperm resulted in greater ruminal ammonia levels (P < 0.05). Dry-rolled corn treatments tended to result in higher molar concentrations of lactate. Relative to nitrogen digestibility, diets containing high moisture corn resulted in greater amounts of microbial nitrogen ow to the duodenum, greater apparent post-ruminal nitrogen digestibility, and greater microbial efciency (P < 0.05). Preservation method of corn grain appears to have a more profound impact on site and extent of nutrient digestibility than corn grain endosperm type.

One hundred and twenty steers (512  37 lb) were stratified by weight and assigned randomly to incremental levels of DDGS treatments. Steers were limit fed a 47.5% alfalfa, 47.5% WCGF 5% supplement diet for five days at the beginning and end of the trial and weighed for three consecutive days to minimize variation due to gut fill. Treatments included 1.5, 2.5, 3.5, 4.5, 5.5, and 6.5 lb DDGS/ head daily adjusted to a percentage of body weight (.29, .49, .69, .88, 1.08, and 1.27 % respectively.) The DDGS contained 12.4% fat and 30.1% CP. Calves were weighed on consecutive days biweekly to adjust the amount of DDGS offered. Minerals and vitamins were added to the DDGS supplements to meet NRC requirements. All steers were individually fed supplement using Calan electronic gates. Thirty calves were selected as a control group and fed a diet of 70.9% brome hay, and 29.1% sorghum silage with DDGS treatments assigned randomly within the group. Diet intake was directly measured for individual steers in the control group. Ninety calves grazed 90 acres of corn residue for 95 days. Grazing calves were gathered every morning at 6:30 and allowed three hours to consume supplement, then returned to the field for grazing. Corn residue samples were collected biweekly using two ruminally canulated heifers and IVDMD was determined.

Corn milling byproducts are expected to increase dramatically in supply. Two primary types of milling processes currently exist, resulting in quite different feed products. The dry milling process produces distillers grains plus solubles, and the wet milling process produces corn gluten feed. These feeds can be marketed as wet feed, or they can be dried and marketed as either dry corn gluten feed or dry distillers grains with or without solubles. For the purposes of this article, only wet corn gluten feed (WCGF) and wet distillers grains plus solubles (WDGS) will be discussed. The majority of plant expansions are dry milling plants; however, an increase in supply of both WDGS and WCGF is expected. Therefore, these feeds may be very attractive for beef producers to use as an energy source. This article will focus on the production, composition of these feeds, energy value and implications, and economics of using WDGS. Some other management issues will be discussed as well including grain processing when these byproducts are used in feedlot diets, roughage level when these byproducts are used, and feeding combinations of WDGS and WCGF. Forage fed situations will not be covered primarily because wet byproducts are not common ingredients in many forage feeding situations. However, wet byproducts work well in forage based diets performing similar to or better than dry byproducts.