Changing distillers grains: implications for cattle performance and management

In the past decade, the ethanol industry has begun changing their production processes to capture more value from the corn kernel, altering the nutrient profile of distillers grains (DG). One of the first methods of value extraction includes partial removal of corn oil, resulting in a decreased oil or fat content of DG. Although the majority of ethanol plants are currently extracting oil from DG, limited research has been conducted regarding the use of new generation DG in finishing cattle diets. Previous research with decreased fat DG has shown varying results in cattle performance when compared to traditional DG. The inconsistency in performance results could be attributed to variation in oil extraction methods and thus, variation in the nutrient profile of new generation DG. Likewise, research evaluating the interaction of corn processing methods and decreased fat DG is limited. Therefore, this research was designed to determine: 1) if feeding moderate levels of wet DG (WDG) plus solubles (WDGS) would decrease the acidosis risk associated with further grain processing and allow fine grinding of corn to improve starch utilization and cattle performance and 2) the impact of feeding WDG produced from a novel cellulosic ethanol process for conversion of corn kernel fiber into cellulosic ethanol (C-WDG) on nutrient digestibility and feedlot performance of ruminants compared to traditional WDG (T-WDG). In experiment 1, it was hypothesized that because WDGS are low in starch concentration, increasing corn surface area would allow for improved starch digestibility while inclusion of WDGS would moderate the risk of acidosis. In diets containing 35% WDGS, apparent total starch digestibility was improved for steers fed finely ground corn (500 microns) compared to steers fed a traditional, dry-rolled corn (2350 microns). However, improved starch digestibility did not translate into improved performance with steers finished on finely ground corn having lighter final BW and decreased DMI and ADG. More recently, the ethanol industry is going beyond oil extraction moving towards fiber extraction. Therefore, a digestibility study utilizing lambs and a steer feedlot study to determine performance were designed to answer the second objective of this thesis. In the first experiment, DM digestibility was lesser in C-WDG compared to T-WDG at both the 30% and 45% inclusions of WDG. While NDF digestibility did not differ across treatments, ADF digestibility was not different between 30% T-WDG, 30% C-WDG, or 45% C-WDG. However, ADF digestibility was greater in lambs fed 45% T-WDG compared to other treatments, suggesting that the secondary fermentation process may be hindering the bioavailability of some portion of the remaining fiber in the C-WDG. In the performance study, steers fed T-WDG had similar final BW and ADG compared to C-WDG. However, steers fed C-WDG had an increased DMI and thus, less efficient G:F which could be explained by the differences in DM digestibility noted in the lamb study. Based on cattle performance, the estimated energy value of C-WDG was decreased by 25% compared to T-WDG. However, based on an economical simulation, the break-even price of C-WDG is similar to T-WDG when calculated based on cattle performance in this study. While digestibility was not evaluated, the addition of corn condensed distillers grains (CCDS) to C-WDG in the feedlot trial resulted in similar feed efficiency while DMI and ADG were decreased compared to C-WDG−fed steers. In summary, new generation DG still added value to finishing diets compared to corn-based diets. These data suggest that feeding 35% WDGS when feeding finely ground corn results in increased starch utilization; however, additional research is needed to determine the optimal particle size and WDGS inclusion to maximize feedlot cattle performance. Furthermore, although WDG produced from secondary fermentation process for converting corn kernel fiber into cellulosic ethanol did result in decreased DM digestibility in lambs, final BW and ADG of steers were still similar to steers fed T-WDG. Overall, addition of new generation WDG in finishing diets maintained an advantage over a corn-based control diet based on cattle growth performance

Performance Comparison of Fall-Calving Cow-Calf Pairs Grazing Cover Crops vs. Traditional Drylot System

Utilization of cover crops as a forage source for the cowherd provides another feed resource at a time when pasture productivity is minimal. However, limited data are available on cover crop utilization by cattle, including cow and calf performance when grazing cover crops. Thus, the objective of this study was to evaluate cow and calf performance while grazing cover crops compared to a traditional, drylot management system of the Beef Teaching fall-calving herd

Utilization of a Modified Delphi Method to Perform a Needs Assessment and Curriculum Revision of a Senior-Level Beef Systems Management Course

Recent, new instructorship of the senior-level beef systems management course (An S 426) presented the opportunity to conduct a thorough evaluation and potential revision of the course curriculum. The objective of this study was to conduct a structured, critical evaluation of the course using a modified Delphi method, and utilize the results to update course objectives and student outcomes. Based on stakeholder feedback, the course is implementing heightened emphases on business and financial planning in addition to the basic managerial principals in the beef production process

Growth and Carcass Characteristics of Feed Efficiency Sorted Cattle Fed Corn or Roughage-Based Diets and Finished with Corn or Byproduct-Based Diets

The current study is part of a five year multidisciplinary grant that aims to identify dietary, genotypic and metabolic factors affecting feed efficiency while also analyzing the effects of feed efficiency differences on feedlot performance and carcass characteristics. The current report serves as a progress update summarizing the first 439 of 1500 total steers that will be fed throughout the duration of the study. Based on the first three groups of steers that have been evaluated, growing phase feed efficiency rank has shown minimal effects on finishing phase growth and carcass traits. Thus far, byproduct-finished cattle have increased hot carcass weight, backfat and yield grade, suggesting distillers grains have a greater energy value than dry rolled corn

Influence of Distillers Grains from a Cellulosic Ethanol Process Utilizing Corn Kernel Fiber on Nutrient Digestibility of Lambs and Steer Feedlot Performance

Two experiments were designed to evaluate the impact of traditional wet distillers grains (T-WDG) compared to wet distillers grains derived from a novel process for conversion of corn kernel fiber into cellulosic ethanol (C-WDG) on nutrient digestibility and animal performance. Experiment 1 utilized 10 wethers in a replicated 5 × 5 Latin square design to evaluate the digestibility of dry matter, fiber, fat, and crude protein in diets containing T-WDG or C-WDG. In experiment 2, 168 crossbred steers were used in a randomized complete block design to determine the impact of T-WDG or C-WDG in finishing diets on performance and carcass characteristics. Although digestibility of T-WDG and C-WDG slightly varied at moderate inclusions in the diet, performance and carcass characteristics of steers fed 30% T-WDG were similar to steers fed 30% C-WDG. Therefore, incorporation of a co-product from a novel, secondary fermentation process for conversion of corn kernel fiber into cellulosic ethanol maintained significant growth performance of cattle when replacing corn in finishing diets

Evaluating the Effects of Diet Energy Density on Hereford Steer Performance with Differing Genetic Potential for Dry Matter Intake

Advancements in beef cattle genetics have allowed for development of dry matter intake (DMI) expected progeny differences (EPD). This study was designed to evalute the effects of altered dietary energy density on feedlot performance of steers sired by Hereford bulls in the top and bottom 40% for their breed in DMI EPDs at the time of EPD introduction to the industry in the Spring of 2016. Sire dry matter intake EPD yielded no differences in live animal performance. While steers fed a lower energy diet (0.63 Mcal/lb NEg) had increased DMI and improved average daily gains, steers fed a higher energy diet (0.68 Mcal/lb NEg) had a 6% advantage in feed conversion. As breed associations and producers start to adopt this novel EPD and accurately use the data generated to improve the EPD accuracy, additional research is needed to more fully evaluate the interaction of diet and genetic potential for DMI

Considerations for Baleage with First Crop Alfalfa

Earlier this spring, we discussed using the PEAQ method (Predictive Equations for Alfalfa Quality) to help determine when to harvest first crop alfalfa. Looking at the PEAQ measurements made around the state, we are getting close to taking the first crop alfalfa. However, the wet conditions could present some challenges with putting up the first cutting of alfalfa in a timely fashion and maintaining feed quality

Influence of Corn Particle Size on Steer Performance and Carcass Characteristics When Fed Diets with Moderate Inclusions of Wet Distillers Grains plus Solubles

A large pen study was conducted with a commercial feedlot to investigate the influence of corn particle size on performance of steers fed diets containing 35% (DM basis) wet distillers grains plus solubles (WDGS). Feedlot cattle in the Midwest are often fed distillers grains from ethanol production that are low in starch. Therefore, this study was designed to evaluate a practical question asked by producers if feeding moderate levels of WDGS would reduce the acidosis risk and allow fine grinding of corn to improve cattle performance. While fine grinding of corn did not improve performance compared to cattle fed a more traditional particle size of corn, starch digestibility of cattle fed finely ground corn was more favorable

Enhancing the Value of Cover Crops through Utilization by Beef Stocker Cattle: Progress Report (Year 2)

The increase in cover crops across Iowa presents a substantial amount of potential forage available to the beef industry that would otherwise go unutilized. While the benefits of improved soil health and nutrient retention through cover crops are well known, limited data are available on utilization by beef cattle. Thus, a study was designed to measure cattle performance while spring grazing cereal rye and to evaluate the impact grazing had on the soil profile. Preliminary data suggests that with proper supplementation, cattle grazing cereal rye may achieve average daily gains of 1.5 to 3.0 lb/d. Initial analysis of soil bulk density indicates minimal negative changes in compaction due to grazing. Because many variables impact the successful integration of cover crops and livestock into row crops, this is a four-year study summarizing data from year two