Transitioning Cattle from RAMP\u3csup\u3e®\u3c/sup\u3e to a Finishing Diet on Feed Intake and Ruminal pH

A metabolism trial was conducted where steers were adapted to high grain diets using a traditional approach or one of two RAMP® adaptation programs. RAMP programs adapted cattle to a finishing diet either gradually over 28 days in four steps or switched to a finishing ration without steps. Feed intake and ruminal pH were monitored continuously throughout the trial. Cattle on the 4-STEP treatment spent more time eating compared to other treatments but total feed consumption was similar among treatments. Ruminal pH was greater for cattle on RAMP adaptation programs when compared to traditional grain adaptation. Cattle fed RAMP for 10 days can be transitioned directly to a finishing diet containing 47.5% Sweet Bran®

Reducing Particle Size Enhances Chemical Treatment in Finishing Diets

Three hundred-sixty calf-fed steers were fed either treated or untreated corn stover that was previously ground through a 1-in or 3–in screen. Treated stover diets improved ADG and F:G compared to untreated. Reducing particle size improved ADG and F:G but did not influence DMI. Compared to a control diet with 5% roughage and 15 percentage units more corn, diets with 20% treated corn stover had similar F:G, ADG, DMI, and carcass quality. Up to 15% additional corn can be replaced with treated corn stover when diets contain wet distillers grains, and may be further enhanced by reducing particle size before chemical treatment

Reducing Particle Size Enhances Chemical Treatment in Finishing Diets

Three hundred-sixty calf-fed steers were fed either treated or untreated corn stover that was previously ground through a 1-in or 3–in screen. Treated stover diets improved ADG and F:G compared to untreated. Reducing particle size improved ADG and F:G but did not influence DMI. Compared to a control diet with 5% roughage and 15 percentage units more corn, diets with 20% treated corn stover had similar F:G, ADG, DMI, and carcass quality. Up to 15% additional corn can be replaced with treated corn stover when diets contain wet distillers grains, and may be further enhanced by reducing particle size before chemical treatment

USE OF ALKALINE TREATED CROP RESIDUES AS PARTIAL GRAIN REPLACEMENTS FOR FINISHING CATTLE

Recently, corn has become expensive and this has led to high feed costs and decreased profitability. High priced corn has allowed for the consideration of other ingredients as replacements to reduce diet cost. In much of the Corn Belt, supplies of wet or modified distillers grains and crop residues are abundant. These ingredients were investigated as corn replacements. Studies were conducted to identify methods for treating crop residues to improve digestibility and value in finishing diets based on corn grain and corn wet distillers grain with solubles (WDGS). Digestibility and value of crop residues were improved by mild chemical treatment. Moisture and temperature affected treatment response and extending reaction times beyond 7 days did not improve digestibility. The magnitude of response to chemical treatment depends on the type of residue (i.e., straw vs. stover) and plant part within corn residue (i.e., husk vs. stalk). Treating crop residues at 50% DM with 5% calcium oxide fed in conjunction with wet or modified distillers grains can replace up to 15 percentage units of corn without hindering performance. It appears that moisture, storage time, and plant part affect response to chemical treatment. Feeding chemically treated crop residues and wet or modified distillers grains is an effective strategy for replacing a portion of corn grain in feedlot diets. Replacing 15% units of corn and all of the untreated roughage with treated crop residue resulted similar nutrient supply to the animal. Reducing grind size, feeding a maximum of 20% treated crop residue, and maintaining at least 25% corn in the diet are strategies for optimizing cattle performance for replacing corn with treated crop residues and distillers grains. Collectively, these studies demonstrate corn replacement options which should reduce diet costs, maintain performance and ultimately increase profitability. Advisers: Galen E. Erickson and Terry J. Klopfenstei

Digestibility of Calcium Oxide Treated Corn Residue with De-Oiled Distillers Grains

A digestion study was conducted to evaluate diets containing calcium oxide treated corn residue in combination with de-oiled distillers grains in forage based growing diets. Chemical treatment did not affect digestibility of DM, OM, or NDF. However, concentration of distillers grains did improve DM and OM digestibility. The use of chemically treated residue in combination with distillers grains in growing diets may not impact diet digestibility

Digestibility of De-Oiled Modified Distillers Grains Plus Solubles in Forage-Based Diets

Over half of Nebraska’s ethanol plants are removing oil from distillers grains via centrifugation of the thin stillage constituent. Removing oil by this method does not impact intake or total tract digestibility in beef cattle growing diets. However, increasing the concentration of de-oiled distillers grains in the diet significantly improved intake and digestibility. Thus, concentration of distillers grain in the diet has a greater impact on total tract digestibility than the fat content in forage-based diets

Effects of Dietary Change on Viral-Bacterial Interactions in the Rumen of Cattle

This ongoing study investigates the impact of diet and bacteriophage activity on the structuring of rumen microbial community composition and diversity. Fistulated cattle were acclimated to a given diet for 21 days before samples were collected and subsequently enriched for viral particles with tangential flow filtration. Taxonomic identification, abundance, and functional attributes were assigned to both bacterial and viral communities. Principle coordinate analysis of the bacterial communities revealed significant clustering based on diet. While diet drives the structuring of rumen bacterial communities, bacteriophages may maintain high, constant bacterial diversity

Factors Influencing Profitability of Calf-Fed Steers Harvested at Optimum Endpoint

Four years of data from calf-fed steers were utilized in determining factors that affect profitability of cattle marketed at an optimum endpoint. Profitability was evaluated on a live weight basis assuming $112/cwt selling price and$180/cwt dressed price. Profit was compared as corn price and Choice-Select spread increased. Overall, carcass weight was the dominant factor in determining profitability. However, at $7 corn, feed efficiency had the most influence on profit. As expected, yield grade decreased and marbling score increased in importance as Choice- Select spread increased. Under these scenarios, profitability was greatly affected by hot carcass weight, with efficiency being the most important at higher corn prices

Effect of 300 or 400 mg Daily of Ractopamine Hydrochloride on Growth Performance and Carcass Characteristics of Finishing Steers During the Last 14, 28, or 42 Days

The effects of ractopamine hydrochloride (Optaflexx®) dosage (0, 300, and 400 mg/head/day) and duration (14, 28, or 42 days) on growth performance were evaluated in feedlot finishing diets. Feeding 300 mg of Optaflexx for 28 or 42 days increased live final BW by 13 and 29 lb, while feeding Optaflexx at 400 mg resulted in 27 or 24 lb increases relative to 0 mg steers, respectively. Feeding 300 mg of Optaflexx for 28 or 42 days would suggest 11.1 or 16.6 lb improvements in HCW, while feeding 400 mg of Optaflexx would suggest 19.7 or 20.7 lb heavier carcasses compared to steers fed 0 mg Optaflexx, respectively

Evaluation of Rumen Metabolism and Digestibility when Treated Crop Residues are Fed in Cattle Finishing Diets

A metabolism trial was conducted to evaluate rumen pH, digestibility, and ruminal VFA concentrations of steers fed 25% CaO treated or untreated cobs, wheat straw, and corn stover. Treated diets had greater digestibility of DM, OM, and NDF compared to untreated diets. Substituting 15 percentage units of corn and 10% roughage with 25 percentage units of 5% CaO treated cobs, wheat straw, or corn stover resulted in similar DM digestibility, rumen pH and VFA concentrations