Implant programs affect performance and quality grade

Selection of dosage, timing, and number of anabolic implants continues to be a source of controversy for feed yard managers and their consultants. Although the dose-dependent effects on performance are fairly well accepted, impacts on carcass quality continue to be debated. This study was intended to summarize effects of different implant programs on performance and carcass quality on the basis of a cross section of available published research

High-dose anabolic implants are not all the same for growth and carcass traits of feedlot

The beneficial effects of anabolic implants with respect to feedlot performance and carcass weight are nearly unequivocal. Although individual prospective studies may have concluded that there are no significant differences between implant dosages, modern production economics demand that any differences, however small, must be gleaned if they are real. The objective of this study was to conduct a meta-analysis of existing data from peer-reviewed as well as industry sources to compare the effects of different doses of anabolic implants on feedlot performance and carcass traits of steers

Bilingual, digital, audio-visual training modules improve technical knowledge of feedlot and dairy workers

Two studies were conducted to determine the effectiveness of digital multimedia modules as training tools for animal care workers. Employees at a commercial feedlot (n = 17) and a commercial dairy (n = 10) were asked to independently complete a 10-question quiz prior to and following viewing of training modules. Module topics in the feedlot were proper handling of non-ambulatory animals and humane methods of euthanasia; modules were administered to the workers, as a group, in either English (n = 7) or Spanish (N = 10), depending on previously indicated worker preference. Modules addressing dairy cattle health practices and dairy cattle handling were presented to the dairy care workers who had a preference for learning in either English (n = 7) or Spanish (n = 3). For feedlot workers, post-test scores were improved by 28% after viewing the modules compared to pre-test scores (74% vs. 58%; P 0.30) between language, topic, and between-test variation, indicating that the modules were equally effective at information delivery to both audiences in both languages. For the dairy workers, test scores improved by 27% from pre-viewing to post-viewing (73% vs. 92%; P < 0.01); there was an interaction between the effect of module and language preference (P < 0.01) indicating that although scores increased for both of the topic areas for the English-speaking workers, only the score for the animal health topic increased for the Spanish-speaking workers. Regardless of nationality, level of formal education, topic, or preferred language, digital media are effective at improving knowledge transfer to animal care professionals

Bedding material in dirt-floor pens reduces heat

Weather-related stressors are a well-recognized opponent to animal welfare and can have important ramifications for animal performance. Sound animal husbandry practices historically have attempted to diminish the effects of deleterious environmental factors. Providing aid to animals when temperatures are above or below their thermal neutral zone (TNZ) can improve animal welfare and/or performance. Because most breeds of cattle are not well equipped to deal with heat, the temperatures at which heat stress can begin to affect cattle can be surprisingly low. The onset of mild heat stress can occur at a temperature humidity index (THI1) value of 75, which can correspond to an ambient temperature as low as 78°F. Aside from food, water, and shelter, arguably the most widely used intervention to counteract the elements is the provision of bedding material during times of cold weather or during events for which the stress of cold may prove too difficult for animals to compensate (i.e., calving, illness, etc.). By providing a layer of insulation as bedding for animals, heat exchange via conduction from their body to the earth is decreased, allowing them to maintain body temperature at a much lower cost to their metabolism. This basic principle of insulation also may be applied in times of heat stress. In an attempt to decrease the effects of heat stress in feedlot cattle, some producers apply wheat straw or grass hay as bedding material, hypothesizing that bedding acts as an insulator from the pen floor, which otherwise serves as a reservoir and conductor of heat. Bedding materials normally are lighter in color than the pen surface, and therefore have less solar heat gain. To the best of our knowledge, no studies have been conducted to examine the effects of these bedding materials on the temperature of the pen surface. Additionally, determining the effects of varying thicknesses of manure on pen surface temperatures may provide useful information for management decisions regarding pen cleaning and maintenance

Limit-feeding a high-concentrate diet may alter nutrient absorption

Feeding newly arrived cattle is commonly characterized by a few days of feeding longstemmed hay followed by a series of step-up diets, wherein concentrate levels are increased to promote ruminal adaptation to a highconcentrate finishing diet. This is done to give the rumen microbes time to adjust to larger amounts of readily fermentable starches in cereal grains. Rumen epithelial adaptation may be achievable by limit-feeding a finishing diet, with gradual increases in feed intake, until the cattle are on full feed. If this can be achieved without causing ruminal disorders and days off feed, then the cost of feeding cattle can be reduced. By limit-feeding, the higher roughage step-up diets are replaced with a single high-concentrate diet. The cost of grain is less than that of roughage, and there are decreased costs in terms of storage space, waste disposal (due to decreased manure production), and mixing and hauling of rations. The purpose of this experiment was to examine the effects of a traditional step-up program versus a limit-fed finishing diet in terms of dry matter intake, acetate to propionate ratio, and ruminal dilution rate. Diet effects on volatile fatty acid concentration and absorption were also examined by using valerate as a marker for volatile fatty acid absorption

Effect of shade on animal welfare, growth performance, and carcass characteristics in large pens of beef cattle fed a beta agonist in a commercial feedlot

Citation: Hagenmaier, J. A., Reinhardt, C. D., Bartle, S. J., & Thomson, D. U. (2016). Effect of shade on animal welfare, growth performance, and carcass characteristics in large pens of beef cattle fed a beta agonist in a commercial feedlot. Journal of Animal Science, 94(12), 5064-5076. doi:10.2527/jas2016-0935Feedlot cattle (n = 1,395; BW = 568 +/- 43 kg) were used to evaluate the effects of shade on animal welfare, growth performance, and carcass quality during the summer of 2013 in a Kansas commercial feedlot. Seven lots of predominately black steers and heifers (4 and 3, respectively) visually determined to be approaching the final mo on feed were identified, randomly gate-sorted, and allocated to pens located across the feed alley from each other to receive 1 of 2 treatments: 1) Shade (mean shade area = 1.5 m(2)/animal) or 2) No shade. Shade was provided using a 13-ounce polyethylene fabric and pens were oriented northwest to southeast. The mean starting date was June 13 and the mean days on feed for lots while on the study was 38 d. Cattle were fed a 77.67% DM steam-flaked corn-based diet and had ad libitum access to water throughout the duration of the trial. Zilpaterol hydrochloride (ZIL) was included in the finishing ration at an inclusion rate of 8.3 mg/kg of DM for the last 20 d on feed with a 3 d withdrawal period. Pen floor temperatures (PFT) were measured using an infrared thermometer and prevalence of cattle open-mouth breathing (OMB) was recorded on a pen basis. In addition to shade treatment, the effect of temperature humidity index (THI) on PFT and OMB was analyzed by classifying days as either "Alert" (THI 79). On the day of slaughter, pens within a replicate were kept separate through all stages of the marketing channel from loading at the feedlot until stunning at the plant. Pen served as the experimental unit for all measurements. There was a THI x shade treatment interaction for PFT and OMB (P 0.05). Heat stress, a significant animal welfare concern and cause of reduced performance in feedlot cattle during the final phase of the feeding period, was alleviated in shaded cattle and illustrates the importance of shade provision as 1 tool to protect the welfare and increase feed consumption in large pens of feedlot cattle during hot summer months

Pathologies of acute interstitial pneumonia in feedlot cattle

Citation: Valles, J. A., Apley, M. D., Reinhardt, C. D., Bartle, S. J., & Thomson, D. U. (2016). Pathologies of acute interstitial pneumonia in feedlot cattle. American Journal of Animal and Veterinary Sciences, 11(1), 1-7. doi:10.3844/ajavsp.2016.1.7Acute Interstitial Pneumonia (AIP) is a costly issue that affects feedlot cattle. Research has yet to elucidate the etiology of AIP; therefore a case-control study was conducted to evaluate possible management and physiological factors that contribute to AIP in feedlot cattle. The experiment was conducted during the summer of 2011 in a commercial feedyard in Kansas. Animals exhibiting clinical signs of AIP and a control animal from the same pen were selected for ante-mortem examination. Post-mortem AIP cases were also selected for additional examination. Ante-mortem measurements included rumen gas cap hydrogen sulfide and pH, rectal temperature and body weight. Post-mortem examination added histological examination of lung tissue. Rectal temperature was greater in the AIP cattle (40.6±0.16°C) than controls (39.7±0.16°C; p0.10). Post-mortem rumen pH values were 6.3±0.4 and 5.7±0.6 for AIP and control cattle, respectively. Histological evaluation of lung samples showed that bronchiolitis was present in about 90% of the cattle affected with AIP. About 75% of the cattle with AIP also had bronchopneumonia. No relationships between feed intake patterns, or serum amylase or lipase levels were noted between treatments (p>0.20). This study generally confirms that AIP tends to occur more in heifers relative to steers, occurs in cattle at heavier weights or later in the feeding period and tends to be associated pathologically with bronchio’ litis and bronchopneumonia. The lack of differences in rumen measures and the feed intake data between AIP and control cattle suggest that feed intake patterns and rumen fermentation may not impact AIP in feedlot cattle and that it may be more directly related to bronchiolitis/bronchopneumonia due to chronic irritation or infection. © 2016 Jose A. Valles, Michael D. Apley, Chris D. Reinhardt, Steven J. Bartle and Daniel U. Thomson

The effects of ractopamine-HCl (optaflexx) on performance, carcass characteristics, and meat quality of finishing feedlot heifers

Beta-adrenergic agonists are commonly used in livestock production to accelerate growth by enhancing lean tissue gain. These compounds repartition nutrients away from fat deposition and toward protein accretion. Generally, increased growth is associated with ractopamine feeding, which improves feed conversion and increases body weight gain. However, little data exists on the effects of ractopamine-HCl on live performance or carcass characteristics of beef heifers. Data released from Elanco Animal Health indicate that differences between gender may exist in response to ractopamine, and therefore appropriate strategies for the administration of this compound must be defined for heifers independent of those for steers. The objective of this study was to determine the effects of Optaflexx, when fed for different dosages over different durations, on finishing heifer performance

Comparative efficacy of two Ivermectin Pour-on anthelmintics in beef steers in a commercial feedyard

Generic products generally have a cost advantage for beef producers over brand-name products. Recently, many beef producers have debated whether to utilize generic anthelmintics in cow/calf herds and feeder cattle. If generics are to be justified, the products must be proven to have efficacy similar to the brand-name product. Previous studies have indicated that generic macrocyclic lactones are less effective in controlling gastrointestinal parasites of cattle than the original brand-name products. The objective of this study was to compare the efficacy of Vetrimec (Norbrook Laboratories Limited, Newry, Co. Down, Northern Ireland) pour-on and Ivomec (Merial Animal Health, Duluth, GA) pour-on by utilizing the fecal egg reduction test in newly arrived feedlot steers

Initial heifer body composition has little impact on response to Zilmax

Using a growth promotant at the correct time of finishing is critical for maximizing profit potential. Previous studies have shown that zilpaterol-HCl (Zilmax; Intervet/ Schering-Plough Animal Health, Millsboro, DE) improves carcass characteristics. The objective of this study was to determine effects of prior body composition on subsequent changes in carcass weight, fatness, and muscle in heifers fed Zilmax so producers can introduce Zilmax at the level of finish that will result in the most desirable response. We hypothesized that fatter heifers use fat as the fuel for muscle growth