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

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

Supplementing Rumen Undegradable Protein to Grazing Cattle

A pooled-analysis of previous Nebraska Beef Report Articles examined the impact of rumen undegradable protein (RUP) supplementation for cattle grazing different types of forage. Each lb of RUP supplement increased ADG by 0.63 lb/d when cattle were grazing smooth brome and 0.43 lb/d when grazing warm season grasses. Cattle did not respond to RUP when grazing summer annuals which were high (18.2%) in CP

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

Evaluation of Models Used to Predict Dry Matter Intake in Forage- Based Diets

Accurately predicting intake is critical to model performance of cattle in order to formulate diets to meet nutritional requirements. Modeling systems must be accurate in order to provide correct information to producers. Multiple studies with growing cattle consuming forage- based diets were summarized. Actual gain and weights of the cattle were used to determine predicted dry matter intake using the Beef Cattle Nutrient Requirements Model (2016). ! e predicted dry matter intakes were compared to observed dry matter intakes to determine accuracy of the prediction model. ! e model over predicted intakes at low TDN and under predicted intakes at higher TDN values, with the interaction at approximately 64% TDN. ! e Beef Cattle Nutrient Requirements Model (2016) does not accurately predict dry matter intake of growing calves consuming forage- based diets

The Effect of Inoculants on Nutrient Losses of Corn Silage and High-moisture Corn Stored in Mini Silos

Two experiments were conducted to determine the effects of inoculants (BONSILAGE CORN 200G and BONSILAGE HMC 200G) containing Lactobacillus buchneri, Lactobacillus plantarum and Pediococcus acidilactici on nutrient losses and aerobic stability of corn silage and high moisture corn. Corn silage and high moisture corn were inoculated and stored in mini silos with nutrient loss and spoilage characterizations at 30, 90, and 120 days with multiple inoculation levels. Longer ensiling times led to greater total acid production. The higher levels of inoculation led to lower total acid production and higher pH. Inoculating corn silage and high moisture corn also affected the fermentation process by decreasing lactic acid production and increasing acetic acid production. The increase in acetic acid production may be partially responsible for the increased aerobic stability observed for the inoculated feeds. Previous research would support our finding of greater stability and lower DM losses with L. buchneri inoculants

Economics of Field Pea Supplementation for Cattle Grazing Crested Wheatgrass

Heifers grazing crested wheat grass were supplemented either field peas or dried distillers grains plus solubles (DDGS) at 0.4% or 0.8% of body weight. Heifers supplemented with field peas had 10% lower daily gain compared to their DDGS supplemented counterparts. The decision to supplement field peas for producers depends on the price at which field peas can be acquired, as well as the distance that DDGS has to be hauled in order to be utilized. Field peas are a viable option in western Nebraska as a supplement for grazing cattle when DDGS is unavailable or field peas are in excess and can be obtained below the human consumption and pet food market price

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

Impact of Corn Silage Inclusion on Nutrient Digestion and Rumen Fermentation in Finishing Cattle

A digestion study was conducted comparing different inclusions of corn silage used as a roughage source on digestibility, feeding behavior and rumen environment. Treatments consisted of 3 inclusions of corn silage at 0, 7.5 and 15% of the diet DM, and a control treatment with 7.5% alfalfa. As expected, increasing available energy and decreasing roughage (either silage or alfalfa) showed an increase in diet digestibility and ruminal propionate concentrations. However, average ruminal pH was least, with more time spent in subacute acidosis (pH \u3c 5.3) when cattle were fed no roughage. These data suggest that feeding cattle increasing silage inclusions as a roughage source prevented ruminal conditions from entering and remaining in subacute acidosis. Feeding corn silage at 15% gave similar digestibility responses compared to 7.5% alfalfa. Including silage as a roughage source at 15% could help prevent acidosis and digestive upset in feedlot cattle

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