Producer Opinions on Antibiotic Use in the Beef Industry

Antibiotic use in the beef industry is of increasing interest to consumers and has become a point of discussion for producers, veterinarians, and professional scientists in recent years. With the vast amount of information available on the internet and social media, consumers are becoming more knowledgeable about beef production practices and the use of antibiotics in the food animal industries. Furthermore, scientists have devoted a large amount of time and money to research to investigate consumer opinions and perspectives about management practices used in food animal production. However, many of these investigations fail to include the opinions and perspectives of the producers who raise these animals. Therefore, the objective of this survey was to explore producer practices and opinions on antibiotic use and antibiotic resistance in the beef industry

Differences in Efficacy Between Gamithromycin, Tilmicosin, and Tulathromycin as Metaphylactic Treatments in High Risk Calves for Bovine Respiratory Disease

The cost of Bovine Respiratory Disease to the beef industry due to death, poorer conversions, and therapy is estimated to cost more than $3 billion per year. Identifying and mitigating Bovine Respiratory Disease in cattle can be difficult due to the increased susceptibility for Bovine Respiratory Disease in high risk cattle. One management option to minimize an outbreak of respiratory disease is the use of metaphylaxis, the mass treatment of a group of calves to reduce the incidence and adverse effects of respiratory disease on high risk animals. Criteria used to determine the necessity of metaphylactic treatment against Bovine Respiratory Disease in feedlots can be based on several factors depending on feedlot preference; however, the primary criteria often considered are: a known history of no previous vaccinations, overall appearance of cattle, source of cattle, Bovine Respiratory Disease in calves received from same source previously, long shipping distance, season of the year, and light arrival weight. The objective of this study was to compare the efficacy of treating newly received, highrisk feedlot calves with gamithromycin, tulathromycin, and tilmicosin as metaphylactic treatments on health and performance characteristics

A Survey of Dry Processed Corn Particle Size and Fecal Starch in Midwestern U.S. Feedlots

Optimizing grain processing practices in cattle feeding operations is critical to reaching maximum feed utilization efficiency. An increased degree of grain processing has consistently shown improved dry matter and starch digestibility; however, it exists with conflicting results on improving performance in finishing cattle. These inconsistencies are likely due to diet composition, such as roughage and co-product level, that could offset the effects of reduced particle size on rate of fermentation thus reducing the risk of digestive dysfunction. Finishing diets are commonly formulated with processed grain to increase utilization of starch and improve animal performance. Processing methods including steam-flaking, grinding, or dry-rolling improve total tract starch digestibility compared with that of whole grain. When dry-rolling corn for finishing cattle, recommendations often suggest that grain be coarsely processed, or cracked to prevent production of an excessive quantity of fine material that could potentially result in an increased rate of fermentation, reduced rumen pH, and digestive disturbances. However, previous research has reported that inclusion of dried distillers grains in finishing diets may influence optimal grain processing method. Grinding corn to a finer particle size when the grain is fed in combination with distillers grains may result in improved total tract starch utilization without causing reduced ruminal pH and digestive disturbances. The objective of this survey was to provide the feedlot industry with an indication of average particle size distribution from current manufacturing practices of dry processed corn, fecal starch content, and co-product and roughage inclusion levels in Midwestern feedlots

Liver Abscess Severity at Slaughter Does Not Affect Meat Tenderness and Sensory Attributes in Commercially Finished Beef Cattle Fed Without Tylosin Phosphate

Liver abscesses are a significant problem in the United States’ cattle feeding industry, costing the industry an estimated $15.9 million annually in liver condemnation, trim losses, and reduced carcass weights and quality grades. Recent reported incidence rates of liver abscesses at slaughter range from 10 to 20%. Liver abscess incidence may be influenced by a number of factors including: breed, gender, diet, days on feed, cattle type, season, and geographical location. Liver abscesses typically occur secondary to rumen insults caused by acidosis or rumenitis. It has been proposed that pathogens associated with liver abscess formation enter the blood stream through damaged rumen epithelium and are transported to the liver through the portal vein where they cause infection, manifested as liver abscesses. Severe liver abscesses have been linked to reduction in hot carcass weight, dressing percentage, yield grade, longissimus muscle area, and marbling scores of carcasses when compared to those with normal livers. However, the effect of liver abscesses on meat tenderness and sensory attributes has not been previously investigated

Flake Density, Roll Diameter, and Flake Moisture All Influence Starch Availability of Steam-Flaked Corn

Steam-flaked corn is commonly fed in feedlot finishing diets because steam-flaking improves starch availability and nutrient utilization, thus improving the overall feeding value of corn. In most operations which utilize steam-flaked corn, grain is processed to a pre-determined flake density by setting the rolls to a specific separation distance and using tension to hold rolls together. Flaked grain is most often produced to a bulk density between 24 and 32 lb/bu, with a common recommendation of 27 lb/bu for corn; however, flake density among steam-flakers within a single mill and among feedlots can vary greatly. Flaking to a similar density using 2 flakers does not ensure similar starch availability. The degree of starch gelatinization or starch availability of steam-flaked corn can be estimated using analytical procedures such as enzymatic hydrolysis, gas production, and steam-flaked corn gelatinization methods. Routinely evaluating starch availability is used as a quality control method to standardize the steam-flaking process to ensure within-day and day-to-day manufacturing consistency. The concentration of readily available starch in steam-flaked corn is indicative of the rate of starch fermentation in the rumen. When starch is too readily available and is fermented at an excessively rapid rate, acid can accumulate in the rumen, reducing ruminal pH, and ultimately resulting in increased prevalence of digestive disturbances. Factors that contribute to variation between feedlot operations with respect to steamflaked corn quality include type and dimensions of flaking equipment, grain type, grain variety and moisture content, roll wear, and steam-flaking procedures. Sampling and handling procedures contribute to precision of results; therefore, sampling procedures need special attention, and consistency must be evaluated when attempting to determine starch availability of steam-flaked corn. The objective of this study was to evaluate starch availability of steam-flaked corn comparing roll dimensions and steam-flaked corn flake densities among flaking systems and feedyards and to provide information on the equipment utilized, steam-flaked corn flaking procedures, and to define current manufacturing practices of steam-flaking in commercial feedlot operations

The effects of dry-rolled corn particle size on performance, carcass traits, and starch digestibility in feedlot finishing diets containing wet distiller's grains

Citation: Schwandt, E. F., Wagner, J. J., Engle, T. E., Bartle, S. J., Thomson, D. U., & Reinhardt, C. D. (2016). The effects of dry-rolled corn particle size on performance, carcass traits, and starch digestibility in feedlot finishing diets containing wet distiller's grains. Journal of Animal Science, 94(3), 1194-1202. doi:10.2527/jas2015-9408Crossbred yearling steers (n = 360; 395 +/- 33.1 kg initial BW) were used to evaluate the effects of dry-rolled corn (DRC) particle size in diets containing 20% wet distiller's grains plus solubles on feedlot performance, carcass characteristics, and starch digestibility. Steers were used in a randomized complete block design and allocated to 36 pens (9 pens/treatment, with 10 animals/pen). Treatments were coarse DRC (4,882 mu m), medium DRC (3,760 mu m), fine DRC (2,359 mu m), and steam-flaked corn (0.35 kg/L; SFC). Final BW and ADG were not affected by treatment (P > 0.05). Dry matter intake was greater and G:F was lower (P 0.10) were observed among treatments for any of the carcass traits measured. Results indicate improved ruminal starch digestibility, reduced fecal starch concentration, and reduced DMI with decreasing DRC particle size in feedlot diets containing 20% wet distiller's grains on a DM basis

Particle Size of Dry-rolled Corn Affects Starch Digestibility but Not Feedlot Performance

Dry-rolling corn is a common practice in feedlots located in the Midwestern and Northern Plains regions of the United States. Optimizing total digestive tract starch utilization in diets containing dry-rolled corn is essential for maximizing efficiency. However, recommendations often suggest that grain be coarsely cracked to avoid producing an excessive amount of fine material that could potentially increase the rate of fermentation, reduce rumen pH, and cause digestive disturbances. Wet distillers byproducts may be effectively used as a protein and energy source for feedlot finishing cattle and can replace a portion of the dry-rolled corn in the diet. The average geometric mean particle size of dry-rolled corn across all feedyards (n = 31) was 0.179 ± 0.035 in. with a range of 0.085 to 0.269 in. The objective of this study was to evaluate the effects of dry-rolled corn particle size on animal performance, carcass traits, and starch digestibility in feedlot finishing diets containing 20% wet distillers grains on a dry matter basis

Probing Correlated Ground States with Microscopic Optical Model for Nucleon Scattering off Doubly-Closed-Shell Nuclei

The RPA long range correlations are known to play a significant role in understanding the depletion of single particle-hole states observed in (e, e') and (e, e'p) measurements. Here the Random Phase Approximation (RPA) theory, implemented using the D1S force is considered for the specific purpose of building correlated ground states and related one-body density matrix elements. These may be implemented and tested in a fully microscopic optical model for NA scattering off doubly-closed-shell nuclei. A method is presented to correct for the correlations overcounting inherent to the RPA formalism. One-body density matrix elements in the uncorrelated (i.e. Hartree-Fock) and correlated (i.e. RPA) ground states are then challenged in proton scattering studies based on the Melbourne microscopic optical model to highlight the role played by the RPA correlations. Effects of such correlations which deplete the nuclear matter at small radial distance (r $<$ 2 fm) and enhance its surface region, are getting more and more sizeable as the incident energy increases. Illustrations are given for proton scattering observables measured up to 201 MeV for the $^{16}$O, $^{40}$Ca, $^{48}$Ca and $^{208}$Pb target nuclei. Handling the RPA correlations systematically improves the agreement between scattering predictions and data for energies higher than 150 MeV.Comment: 20 pages, 7 figure

Bulls Are More Efficient Than Steers with Similar Meat Quality

Bull breeding soundness evaluations are often performed as a critical component of beef cow herd management to ensure that herd bulls have adequate semen quality, are physically capable of enduring the breeding season, and to determine the serving capacity per bull. Currently, there are approximately 30.3 million beef cows and 2.1 million bulls in the U.S. Depending on the breeding soundness evaluation failure rate, there are likely several hundred thousand bulls which will enter the beef market annually and a portion will be young bulls with the potential to be fed and sold to produce saleable meat of choice or select quality grade. Castration of male cattle is a common procedure that is practiced world-wide, but is more common in the U.S. than in many countries. Behavioral benefits from castration include reduced aggressiveness and sexual activity by reducing testosterone levels. In addition, castrated animals maintain a lower muscle pH post-harvest producing fewer “dark cutters.” Bulls have greater feeding performance and efficiency than steers. However, a bull’s ability to gain efficiently and produce a leaner carcass, with more value to the packer and retailer, is overshadowed by the perception that meat from bulls is less tender than meat from steers. Castration methods and the age at castration influence the potential stress on the animal, resulting in concerns regarding animal welfare and animal performance; therefore, castration of post-pubertal bulls to improve meat quality should be re-evaluated. The objective of this study was to evaluate the effects of castration and the use of growth promotion technologies in post-pubertal bulls on feeding performance, carcass traits, and meat quality characteristics compared to intact post-pubertal bulls

Prevalence of Horns in a Pen Does Not Affect Incidence of Carcass Bruising in Feedlot Cattle

Disbudding and dehorning are two common practices done to remove horns from cattle to prevent injury to handlers and other cattle and to reduce bruising of carcasses. Bruised carcasses result in substantial reduction in profit due to trim loss, increased sanitation risk, and loss in time on the rail during processing. Previous research has indicated that cattle with horns increased hide damage of cohorts and caused injury to handlers. Cattle with horns cause circular shaped bruises that lead to trim loss due to bruising. Cattle with tipped horns do not have a lower bruising rate than cattle with intact horns. The objective of this study was to evaluate the effect of horn prevalence within groups of slaughter animals and the incidence of bruising on the carcasses of those same cattle