Evaluation of the Water Footprint of Beef Cattle Production in Nebraska

Data were compiled on feed usage to model the amount of water needed to produce beef in typical Nebraska production systems. Production systems where cows were wintered on corn residue utilized 18% less water than systems utilizing native range as a wintering source, because of water allocations. Therefore, the water footprint (gallons of water required to produce one pound of boneless meat) was decreased by 18%. In addition, increasing the dietary inclusion of distillers grains from 0% to 40% decreased the water footprint in the finishing phase by 29%, again based on water allocation. Utilizing corn residue and distillers grains in Nebraska beef cattle systems decreases the overall water footprint of production. Additionally, the water footprint of the systems analyzed was 80% green water as rain, minimizing the environmental impact of beef production on freshwater use and ecological water balance

Evaluation of the effects of wood-sourced biochar as a feedlot pen surface amendment on manure nutrient capture

Feedstuffs utilized in U.S. feedlot finishing rations incorporate high concentrations of N and P, with less than 15% of fed N and P retained by the animal. The remaining N and P are excreted in the manure, where the opportunity for manure N loss via ammonia (NH3) volatilization from the feedlot pen surface is a risk to the environment and lowers the value of manure as a fertilizer. Two nutrient mass balance experiments were conducted during the winter and summer seasons to evaluate the effects of spreading unprocessed Eastern red cedar biochar onto the feedlot pen surface on manure nutrient capture and cattle performance. A 186-d feedlot fnishing experiment was conducted from December to June (WINTER) and a subsequent 153-d fnishing experiment was conducted from June to November (SUMMER). The WINTER experiment evaluated three treatments (5 pens per treatment; 10 steers per pen), including biochar spread on pen surface during the feeding period (1.40 kg biochar/ m2 ; 17.6 m2 /steer soil surface of the pen), hydrated lime spread on pen surface at end of feeding period (1.75 kg/m2 ) and control (no treatment applied). The SUMMER experiment evaluated biochar treatment (1.40 kg biochar/m2 ; 5 pens per treatment; 8 steers per pen; and 22 m2 /steer soil surface of the pen) against control. There were no differences in N and P intake, retention, or excretion (P ≥ 0.38) between WINTER treatments. Steer performance (P ≥ 0.10) and carcass characteristics (P ≥ 0.50) were not impacted by pen treatment in WINTER. Nitrogen and P intake and excretion (P ≥ 0.35) were not different between treatments in SUMMER and retention of N and P was signifcantly greater for the biochar treatment (P ≤0.04) due to greater ADG (P = 0.05). There was no difference in DMI (P = 0.48) in SUMMER, steers on biochar pen treatment had heavier HCW (P = 0.05) and greater ADG, resulting in a tendency for greater feed effciency (P = 0.08). In both experiments, biochar addition to the pen surface tended (P = 0.07) to increase manure N as a percent of manure DM, but this increase in N concentration did not impact kg of N removed from the feedlot pens (P ≥ 0.15) or N losses (P ≥ 0.68). The addition of red cedar biochar to the feedlot pen surface did not increase manure nutrient capture of N or P and did not reduce N losses associated with soil-based feedlot pens

Effects of Supplemental SoyPass in Forage-Based Diets Containing Distillers Grains on Performance of Growing Steers

SoyPass was supplemented in two grass hay diets containing 20% or 35% wet distillers grains with solubles (WDGS) to analyze the effects on growing cattle performance. The SoyPass supplement replaced 0, 30, or 60% of dietary WDGS for a total of 6 treatments with a factorial design. Substituting SoyPass into the diet did not affect average daily gain (ADG) of calves; however, calves consuming the 35% WDGS diet gained 31% more than the 20% WDGS treatment calves. Dry matter intake (DMI) and feed to gain (F:G) increased linearly in the 35% WDGS diet with the inclusion of SoyPass. In the 20% WDGS diet, DMI and F:G were maximized when SoyPass replaced 30% of the WDGS and lowest when SoyPass replaced 60% of WDGS. Therefore, SoyPass can replace up to 60% of the WDGS in forage based diets containing 20% WDGS with no adverse effects on performance by appearing to supply needed lysine

Uncertainties in life cycle greenhouse gas emissions from U.S. beef cattle

Beef cattle feedlots are estimated to contribute 26% of U.S. agricultural greenhouse gas (GHG) emissions, and future climate change policy could target reducing these emissions. Life cycle assessment (LCA) of GHG emissions from U.S. grain-fed beef cattle was conducted based on industry statistics and previous studies to identify the main sources of uncertainty in these estimations. Uncertainty associated with GHG emissions from indirect land use change, pasture soil emissions (e.g. soil carbon sequestration), enteric fermentation from cattle on pasture, and methane emissions from feedlot manure, respectively, contributed the most variability to life cycle GHG emissions from beef production. Feeding of coproducts from ethanol production was estimated to reduce life cycle emissions by 1.7%, but could increase emissions by 0.6–2.0% with higher feeding rates. Monte Carlo simulation found a range of life cycle emissions from 2.52 to 9.58 kg CO2 per kg live weight (5th and 95th percentiles), with a calculated average of 8.14, which is between recent estimates. Current methods used by the U.S. Environmental Protection Agency (EPA) associated with beef production in feedlots were found to account for only 3–20% of life cycle GHG emissions. Includes Supplementary Information/Appendix A

Effect of Micro-Aid\u3csup\u3e®\u3c/sup\u3e Supplementation on Nitrogen Losses from Manure

A 2x2 factorial designed experiment was used to study the effects of Micro-Aid and time on OM and N losses from manure, in a simulated feedlot pen setting. Manure was collected from cattle on a common diet, except for the addition of 1 g Micro-Aid /steer daily. Losses of OM were greater at 60 d than 30 d, and greater for control than Micro-Aid. Nitrogen losses at d 30 were similar between treatments but control pans had greater N losses at d 60. Feeding Micro-Aid to cattle may inhibit N volatilization from manure, enhancing the fertilizer value of manure

Effect of Micro-Aid\u3csup\u3e®\u3c/sup\u3e Supplementation on Nitrogen Losses from Manure

A 2x2 factorial designed experiment was used to study the effects of Micro-Aid and time on OM and N losses from manure, in a simulated feedlot pen setting. Manure was collected from cattle on a common diet, except for the addition of 1 g Micro-Aid /steer daily. Losses of OM were greater at 60 d than 30 d, and greater for control than Micro-Aid. Nitrogen losses at d 30 were similar between treatments but control pans had greater N losses at d 60. Feeding Micro-Aid to cattle may inhibit N volatilization from manure, enhancing the fertilizer value of manure

Predicting Feedlot Growth Performance over the Feeding Period Utilizing Steer Age and Body Weight

A pooled- analysis of UNL feedlot pens examined the effects of steer age and body weight on feedlot growth performance. For data analysis, pens were divided into 3 subclasses based on steer age (calf- fed, short yearling, or long yearling) and, grouped based upon initial body weight (500 to 1200 lb, in 100 lb increments) within each age class. As initial body weight increased, DMI (lb/d) for the whole feeding period increased quadratically in calf-fed steers and increased linearly in short and long yearlings. A quadratic increase in ADG was observed in calf- feds as initial body weight increased. No differences in ADG were observed for short and long yearlings due to initial body weight. As heavier cattle were placed within age group, feed conversion increased linearly. Predicting DMI is more consistent when expressed as % of body weight. Predicting intake and growth performance over the entire feeding period, in order to facilitate management decisions, is dependent upon steer age and initial weight when starting the finishing diet

Pooled Analysis of Individually Fed Finishing Trials

A pooled analysis of 21 finishing trials (2002–2016; 1530 animals) with cattle individually fed in Calan gate barns was conducted. Mixed model regression analysis following random coefficient methodology was used to evaluate relationships between performance variables and carcass characteristics. Gain had a greater effect on efficiency (R2 = 0.72) compared to intake (R2 = 0.02). The relationship between gain and efficiency was cubic, while intake had a quadratic relationship. The cubic response of gain relative to efficiency was continually increasing with relatively slight curves in the line heavily influenced by points that lay on the ends of the data. Efficiency also had cubic relationships with fat thickness and marbling of carcasses; however, the regressions had low R2 values of 0.01. There was a significant relationship between efficiency and fat thickness and marbling, but the variation around the trend line was high. Efficiency alone is a poor predictor of fat thickness and marbling

Evaluation of Condensed Algal Residue Solubles as an Ingredient in Cattle Finishing Diets

A study was conducted to evaluate feeding 0, 2.5, or 5.0% of a novel liquid feed, Condensed Algal Residue Solubles (CARS), in one of two base diets with CARS replacing corn. ! e two base diets were fed to mimic Northern Great Plains (high moisture and dry rolled corn blend fed with wet distillers grains plus solubles) and Southern Great Plains (steam- flaked corn and dry distillers grains plus solubles) feedlot diets. ! ere were no interactions between base diet and CARS inclusion. Feed intake and longissimus muscle area decreased as CARS inclusion increased in the diet. A quadratic effect was shown for average daily gain, feed efficiency, final adjusted body weight, hot carcass weight, 12th rib fat, and yield grade, increasing as CARS was included up to 2.5% of diet dry matter, then decreased at 5% inclusion. Marbling score improved with increased inclusion of CARS, with the highest score at 5% CARS inclusion. Including CARS at 2.5% of diet dry matter improved feed efficiency in both Northern and Southern Great Plains diets

Economic Analysis of Increased Corn Silage Inclusion in Beef Finishing Cattle

An economic analysis was conducted to assess the feasibility of feeding greater inclusions of corn silage in finishing diets. Cattle were fed two inclusions of corn silage (15 and 45% of diet dry matter) with or without tylosin. Cattle fed 15% corn silage with tylosin had the best feed conversion, 15 % corn silage without tylosin was intermediate, and both 45% corn silage with and without tylosin had the poorest feed conversion. Feeding corn silage at greater inclusions decreased ADG but increased final body weight when fed to an equal fatness (28 days longer). However, feeding corn silage at 45% was more economical compared to feeding 15% corn silage, especially at higher corn prices, provided shrink is well managed (less than 15%). Feeding elevated concentrations of corn silage may have an economic advantage while also offering the addition of liver abscess control in finishing diets without tylosin