Beef Feedlot Research Articles

Individual Beef Cattle Identification Using Muzzle Images and Deep Learning Techniques.

Simple SummaryThe ability to identify individual animals has gained great interest in beef feedlots to allow for animal tracking and all applications for precision management of individuals. This study assessed the feasibility and performance of a total of 59 deep learning models in identifying individual cattle with muzzle images. The best identification accuracy was 98.7%, and the fastest processing speed was 28.3 ms/image. A dataset containing 268 US feedlot cattle and 4923 muzzle images was published along with this article. This study demonstrates the great potential of using deep learning techniques to identify individual cattle using muzzle images and to support precision beef cattle management.Individual feedlot beef cattle identification represents a critical component in cattle traceability in the supply food chain. It also provides insights into tracking disease trajectories, ascertaining ownership, and managing cattle production and distribution. Animal biometric solutions, e.g., identifying cattle muzzle patterns (unique features comparable to human fingerprints), may offer noninvasive and unique methods for cattle identification and tracking, but need validation with advancement in machine learning modeling. The objectives of this research were to (1) collect and publish a high-quality dataset for beef cattle muzzle images, and (2) evaluate and benchmark the performance of recognizing individual beef cattle with a variety of deep learning models. A total of 4923 muzzle images for 268 US feedlot finishing cattle (>12 images per animal on average) were taken with a mirrorless digital camera and processed to form the dataset. A total of 59 deep learning image classification models were comparatively evaluated for identifying individual cattle. The best accuracy for identifying the 268 cattle was 98.7%, and the fastest processing speed was 28.3 ms/image. Weighted cross-entropy loss function and data augmentation can increase the identification accuracy of individual cattle with fewer muzzle images for model development. In conclusion, this study demonstrates the great potential of deep learning applications for individual cattle identification and is favorable for precision livestock management. Scholars are encouraged to utilize the published dataset to develop better models tailored for the beef cattle industry.

The GHG Protein Ratio: An Indicator Whose Time Has Come

The Carbon Footprint (CF) of agriculture must be substantially reduced to help avoid catastrophic climate change. This paper examines the ratio of Greenhouse Gas (GHG) emissions to protein as an indicator of the CF of the major Canadian livestock commodities using previously published results. The GHG emissions for these commodities were estimated with a spreadsheet model that accounted for all three GHGs, the complete life cycles of each livestock type and the livestock interactions with the agricultural land base. The indicator results reviewed here included the responses to livestock types and diets, livestock versus plant protein sources, spatial scales and geographic differences. The sensitivity of the results shown suggest that GHG-protein ratios could provide valuable guidance for producers and consumers to reduce their GHG emissions. For example, diverting feed grains from beef feedlots to hog production would substantially reduce the CF of red meat, although still not as low as the CF of poultry products. The complete proteins derived from pulses have much lower CF values than all livestock products.

Acute interstitial pneumonia and the biology of 3-methylindole in feedlot cattle.

Acute interstitial pneumonia (AIP) of cattle has been recognized for many decades. While the pathogenesis and risk factors for this condition in pastured cattle are relatively well characterized, there remains a poor understanding of the disease as it occurs in intensively fed cattle such as in beef feedlots. Specifically, in pastured cattle, AIP results from excessive ruminal production of the pneumotoxicant 3-methylindole (3-MI). In feedlot cattle, the evidence to substantiate the role of 3-MI is comparatively deficient and further investigations into the cause, pathogenesis, and control are sorely needed. This review highlights our current understanding of AIP with a focus on the disease as it occurs in feedlot cattle. Additionally, it illustrates the need for further work in understanding the specific animal factors (e.g. the ruminal microbiome, and the role of concurrent diseases), management factors (e.g. animal stocking and vaccination protocols), and dietary factors (e.g. dietary supplements) that may impact the development of AIP and which are relatively unique to the feedlot setting. All stakeholders in the beef industry stand to benefit from a greater understanding of what remains a pressing yet poorly understood issue in beef production.

Development of a welfare assessment protocol for practical application in Argentine feedlots

The intensification of livestock farming has led to the expansion of feedlots in many countries and Argentina is not an exception. As in any other husbandry context, there is a need to objectively adopt an evidence-based approach to monitoring animal welfare in feedlots. This research aimed to describe the stages that took part in the development process of Bienest.AR, a beef cattle evaluation protocol adapted to the different conditions of the national feedlots, respecting validity, reliability, and feasibility criteria. The process to achieve this goal included the following seven stages: 1- Identification of welfare indicators considering animal- (ABM), resource- (RBM) and management-based measurements (MBM), by organising them according to the FAWC Five Freedoms, the Five Domains Model, and the welfare principles and criteria applied by Welfare Quality® and AWIN methods; 2- Validation of Gold Standards; 3- Evaluator’s training and first reliability testing by Spearman's Rank correlation coefficient; 4- Selection of indicators through focus groups; 5- Field application on 25 farms; 6- Feasibility and second reliability testing by Kendall Correlation Coefficient; and 7- Weighing of indicators and defining the classification method. Of the 150 candidate measurements initially obtained from the literature review, 57 were pre-selected and 28 were finally selected based on their validity, reliability and practicality to integrate the final protocol (18 ABM, 8 RBM and 2 MBM). In addition, the final protocol included information about: preliminary interview; sampling order; estimated evaluation time; sample size; equipment required; and steps to follow from arrival at the farm until completion of the evaluation. The protocol was applied in 25 feedlots and 54,238 animals, and required a minimum time of 290 min to a maximum of 495 min to be completed. Statistically significant (p < 0.05) concordance among the observers was found for all the selected ABM analysed using Spearman's rank correlation coefficient. Given the simplicity for its evaluation, the reliability of RBM and MBM included in this protocol has not been evaluated. This research allowed the development of the first standard welfare assessment protocol for beef cattle feedlots in Argentina. Further applications of the described welfare assessment tool in many feedlots will reinforce the validation of the proposed measurements and allow the diagnosis of the global situation of animal welfare in feedlots in Argentina and other countries applying comparable fattening systems.

Effect of dietary addition of phenolic compounds from propolis on growth performance, carcass traits, and meat fatty acid profile of feedlot beef cattle

Twenty-four male Nellore steers (445 ± 31 kg initial body weight) were used to evaluate the effects of different doses of phenolic compounds from a propolis-based product (PBP) on growth performance, carcass traits, and meat fatty acid (FA) profile. The total mixed ration consisted of 470 g kg-1 corn silage and 530 g kg-1 concentrate (dry matter [DM] basis), which were randomly assigned to one of three treatments: control (CON, without phenolic compounds from the propolis extract), PBP1 (225 mg of phenolic compounds g-1 of propolis dry extract), and PBP2 (300 mg of phenolic compounds g-1 of propolis dry extract). The animals were fed in a feedlot for 84 days and presented an average final body weight (FBW) of 542 kg. Dietary addition of phenolic compounds had no overall effect on growth performance. Mean values for dry matter intake, average daily gain and feed conversion ratio were 9.99 kg d-1, 1.14 kg d-1 and 8.82 kg DM kg gain-1, respectively. Hot carcass weight and hot carcass yield had average values of 308 kg and 56.8%, respectively. In addition, carcass traits did not change after PBPs were added to the diet, except for the ribeye area, which was higher for PBP2 (21.5 cm2 100 kg-1) than for PBP1 (18.6 cm2 100 kg-1). Dietary addition of PBPs maintained redness better than the controls after 9 days in the refrigerator; no major changes were observed in the meat FA profile after the addition of PBPs to the diet. These results suggest that phenolic compounds present in propolis (300 mg g-1) have positive effects on meat color and improve the sensory quality of meat.

A new equation to predict dry matter intake by Nellore beef cattle in commercial feedlots in Brazil

This study aimed to create an equation to predict the dry matter intake (DMI) of Nellore cattle using intake data from Azevedo et al. (2016) and intake data from animals raised in commercial feedlots in Brazil. This equation will then be compared with other equations already published. A correlation analysis between performance variables and DMI was performed. The metabolic body weight (MBW), average daily gain (ADG) and average daily gain squared (ADG2) variables were included in the model to generate the prediction equation using SAS software. The new prediction equation was validated according to accuracy and precision in two feedlots. After validation, the new equation was compared to Equation 2.1 published by Azevedo et al. (2016) and other equations published by McMeniman et al. (2010), Anele et al. (2014) and Silva et al. (2021) in two other commercial feedlots using the software Model Evaluation System v. 3.2.3. The proposed equation for commercial feedlots was DMI = -2.1948 + 0.08338 * MBW + 3.9328 * ADG - 0.9030 * ADG2. Neither the equations proposed by Anele et al. (2014) and Silva et al. (2021) nor Equations 3 and 4 published by McMeniman et al. (2010) proved to be adequate in predicting intake in commercial feedlots. The Azevedo et al. (2016) Equation 2.1 and the new equation generated in the commercial herd in tropical conditions accurately predicted the actual intake of validation herds 1 and 2. Equation 5 proposed by McMeniman et al. (2010) was accurate and precise to predict the actual intake only in feedlot 2. However, the new equation presented better accuracy and precision indicators. This new equation is more adequate in predicting the intake of Nellore beef cattle in commercial feedlots. The new equation can make feedlot beef cattle feeding systems in Brazil more accurate in tropical conditions and, therefore, more suitable.

36 Kansas State University Feedlot Boot Camp and Teaching Program: Growing Student Interest and Engagement in the Feedlot Industry

Abstract The Kansas State University Collegiate Feedlot Boot Camp and Teaching Program was initiated in January 2019 with the goal to develop student knowledge, skills, and professional relationships in feedlot management to help meet critical need for trained professionals in the feedlot industry. Allied industry supporters including feedlot nutrition and veterinary consultants, pharmaceutical companies, and lenders, as well as feedlot owners/managers and the Kansas State University Department of Animal Sciences and Industry collaborated to develop, sponsor, and offer the program, which is offered at no cost to students who are selected. Specific objectives are to train students in aspects of feedlot management through a 4-d comprehensive “Boot Camp” at Western Kansas feedlots, enhance students’ likelihood of participating in feedlot internships, and cultivate students’ vision of potential career paths within the industry. Boot Camp topics include cattle health, feeding and nutrition, feedlot design and maintenance, and the business of cattle feeding. A networking dinner brings students and feedlot managers together to facilitate students gaining internship and full-time employment with feedlots. Following the January Boot Camp, students share individual presentations on relevant industry topics. Presentations are recorded and shared with feedlot managers to further engagement between students and feedlot managers. Later in the spring semester students also participate in a half-day cattle processing experience at a feedlot near Kansas State to provide additional insight and experience with feedlot health management. Limited to 20 participants per year, 59 undergraduate students have completed the program. When surveyed, over 98% (58/59) of student participants agreed with the statement “My interest in pursuing an internship and (or) career in the feedlot industry grew as a result of this Boot Camp.” Approximately 50% of students participated in feedlot internships or earned full-time jobs working in feedlots. Ranging from students with little to no experience with feedlots to being raised on beef cow-calf or feedlot operations, progress is being made in growing student interest and awareness of career opportunities in the feedlot industry.

225 Effect of Increasing Doses of Encapsulated Butyric Acid and Zinc on Beef Feedlot Steer Growth Performance, Dietary Net Energy Utilization, and Carcass Characteristics

Abstract The objective of this study was to determine the effects that increasing doses of encapsulated butyric acid and zinc (BPZ) have on beef feedlot steer growth performance, dietary net energy utilization, and carcass characteristics. Steers (n = 272; shrunk BW = 360 kg ± 74 kg) were assigned to dietary treatment [0 (CON), 1, 2, or 3 g BPZ/kg diet DM] in a randomized complete block design (RCBD) with pen (n = 32) as experimental unit. Cattle were fed until visually assessed to have 1.27 cm rib-fat and were shipped for harvest at a commercial beef abattoir. Carcass and liver health data was recorded. Feedlot performance data was calculated on a carcass-adjusted basis (HCW/0.625). Data were analyzed as a RCBD with fixed effects of BPZ inclusion level and block was considered a random effect; pre-planned contrasts for CON vs. BPZ, plus linear, and quadratic responses were tested. No differences (P ≥ 0.14) were observed for final BW, DMI, ADG, feed conversion efficiency, observed dietary NEm and NEg, observed-to-expected dietary NEm and NEg, HCW, REA, rib-fat thickness, marbling score, estimated EBF, or distribution of USDA YG 1, 3, 4, 5, and USDA quality grade among treatments. A tendency (P = 0.10) was observed for CON vs. BPZ for calculated YG. Tendencies were detected for USDA YG 2 carcass distribution (linear; P = 0.07) and for normal and abscessed liver prevalence (quadratic; P = 0.08). Dressed yield tended to be greater (P = 0.08) for BPZ vs. Con and increased with dose (linear; P = 0.05). Supplementation of BPZ in finishing cattle diets does not appreciably influence growth performance, but increases dressed yield. Data from this study suggests that the addition of BPZ to feedlot finishing diets for decreasing the prevalence of abscessed livers should be further investigated.

Crossbreeding beef sires to dairy cows: cow, feedlot, and carcass performance.

Genetic and reproductive advancements in the dairy industry, volatile milk markets, and beef packer restrictions on dairy carcasses have increased the popularity of crossbreeding beef sires to dairy cows in the United States. This observational study aimed to understand performance of dairy cows bred to beef sires and feedlot and carcass performance of crossbred beef × dairy cattle. For dairy cow performance, archived records from two dairies representing two successive lactations were evaluated in cows (Dairy A: n = 72/group; Dairy B: n = 456/group) representing 1) All Dairy, where previous sire type of conception was Holstein for both lactations, or 2) Beef on Dairy, where previous sire type of conception was Holstein for the preceding lactation and a beef breed for the subsequent lactation. For feedlot performance, closeout data from pens (n = 26/cattle type) of beef and beef × dairy steers and heifers were evaluated. For carcass performance, individual carcass data were compared between conventional beef (n = 966), beef × dairy (n = 518), and Holstein (n = 935) steers sampled across a variety of processing facilities, harvest lots, and geographical regions. Cow lactation performance was minimally impacted by sire type of previous conception. Cows conceived to beef sires exhibited a 2 to 3 d greater (P < 0.01) gestation length than cows conceived to Holstein sires. Beef × dairy cattle were not largely different in weight gain at the feedlot but exhibited 1-unit lesser (P < 0.01) dressing percentage than beef cattle. Beef × dairy carcasses possessed 18% lesser (P < 0.05) 12th rib fat thickness than beef cattle and 5% greater (P< 0.05) ribeye area than dairy cattle. Additionally, beef cattle produced nearly double (P < 0.05) the percentage of yield grade 4 carcasses produced by beef × dairy and Holstein cattle.

Feedlot pens with greenhouse roofs improve beef cattle performance in temperate weather.

Muddy pens can negatively affect welfare and performance of feedlot beef cattle. In some regions with temperate weather, plastic greenhouse covers, above the entire pens are used to fatten cattle in a clean and dry environment. The objective of this research was to investigate effects of greenhouse roofed pens on beef cattle feedlot performance in temperate weather. Data were collected from a feedlot located in Central Mexico between 2016 and 2019. The study included 1,062 closeouts of pens with 68,305 crossbred bulls fed in pens with or without a greenhouse roof. Feeding ranged from 82 to 210 d, depending on the initial weight of cattle, which ranged from 255 to 511 kg. For each pen, average daily dry matter intake (DMI; kg of DMI·animal−1·d−1), average daily gain (ADG, kg·animal−1·d−1), and feed efficiency (G:F, ADG/DMI) were measured. Factorial analyses were performed to test the interaction and main effects of initial weight grouping (light, medium, and heavy), roof, and season as fixed effects, and year as a random effect. None of the three-way interactions were significant (P > 0.51). There was no initial weight grouping × roof interactions for DMI and ADG (P > 0.31). There was (P = 0.03) an initial weight grouping × roof interaction for G:F, as pens of all initial weight groups had greater (P < 0.01) G:F in pens with greenhouse roof than its counterpart in pens without greenhouse roof, but the advantage was greater for pens with light cattle (0.178 vs. 0.166; P < 0.01). There was no initial weight grouping × season interactions for all variables (P > 0.39). There was no roof × season interaction for DMI (P = 0.47), but there were interactions for ADG and G:F (P < 0.01). The ADG was not different (P > 0.13) during summer and autumn based on the roofing system, but pens with greenhouse roofs had greater ADG during spring (1.70 vs. 1.61) and winter (1.68 vs. 1.64; P ≤ 0.01). The G:F was greater (P < 0.01) in all seasons for pens with a greenhouse roof, with the most prominent advantage during spring (0.173 vs. 0.160). There were main effects for cattle initial weight grouping and roof for all variables (P < 0.01). Season affected DMI and G:F (P < 0.01). Pens with greenhouse roofs had decreased DMI (9.70 vs. 9.86), greater ADG (1.67 vs. 1.63), and increased G:F (0.173 vs. 0.166) compared to pens without greenhouse roofs (P < 0.01). Pens with greenhouse roofs in feedlots located in temperate regions positively affect beef cattle performance.

Effects of increasing supplemental zinc in beef feedlot steers administered a steroidal implant and beta agonist.

Ninety-two Angus-crossbred steers (424 ± 28.3 kg initial body weight) were used in a 98-d study to assess the effects of increasing Zn supplementation on cattle performance, liver and plasma trace mineral concentrations, blood metabolites, and carcass characteristics. All steers were implanted with a Component TE-200 (200 mg trenbolone acetate + 20 mg estradiol; Elanco Animal Health, Greenfield, IN) on d 0 and fed 300 mg‧steer−1‧d−1 of ractopamine hydrochloride (Zoetis, Parsippany, NJ) from d 70 to 98. Cattle were fed via GrowSafe bunks (GrowSafe Systems Ltd., Airdrie, AB, Canada), and steer served as the experimental unit (n = 22 or 23 steers/treatment). Supplemental Zn was administered through the diet at 0, 100, 150, or 180 mg Zn/kg on a dry matter basis from ZnSO4 (Zn0, Zn100, Zn150, or Zn180, respectively). Cattle were weighed on d −1, 0, 9/10, 20, 41, 59, 69, 70, 78/79, 97, and 98. Blood was collected on d 0, 9/10, 69, 78/79, and 97, and liver biopsies on d 9/10 and 78/79 (n = 12 steers/treatment). Data were analyzed as a complete randomized design. Contrast statements were formed to test the linear, quadratic, and cubic effects of Zn supplementation and test Zn0 vs. Zn supplementation. Day 10 and 70 body weight (BW) and d 0 to 10 and 0 to 70 average daily gain were linearly increased with Zn supplementation (P ≤ 0.05), and greater for Zn supplemented steers (P ≤ 0.03). No effects of Zn supplementation were observed on final BW, dressing percentage, ribeye area, 12th rib fat, or marbling (P ≥ 0.11). Hot carcass weight tended to be 7 kg greater for Zn supplemented steers than Zn0 (P = 0.07), and yield grade linearly increased with increasing Zn supplementation (P = 0.02). Day 10 liver Mn concentrations tended to quadratically decrease (P = 0.08) with increasing Zn supplementation, though d 79 liver Mn concentrations and arginase activity were not influenced by Zn (P ≥ 0.28). Day 10 liver arginase activity tended to be (r = 0.27; P = 0.07) and d 10 serum urea nitrogen was correlated with d 10 liver Mn (r = 0.55; P < 0.0001). Zinc supplementation linearly increased d 10 liver Zn and d 10, 69, 79, and 97 plasma Zn concentrations (P ≤ 0.05). A cubic effect of Zn was observed on d 79 liver Zn (P = 0.01) with lesser liver Zn in Zn0 and Zn150 steers. These data suggest increasing dietary Zn improves growth directly following the administration of a steroidal implant and that steroidal implants and beta agonists differ in their effects on protein metabolism.

Long-duration transit and food and water deprivation alter behavioral activities and aggressive interactions at the feed bunk in beef feedlot steers.

The objective of these experiments was to assess the effects of food and water deprivation and transit duration on the behavior of beef feedlot steers. In Experiment 1, 36 Angus-cross steers (353 ± 10 kg) were stratified to 6 pens and assigned one of three treatments (n = 12 steers per treatment): control (CON; stayed in home pens with ad libitum access to feed and water), deprived (DEPR; stayed in home pens but deprived of feed and water for 18 h), or transported (TRANS; subjected to 18-h transit event and returned to home pens). In Experiment 2, 60 Angus-cross steers (398 ± 5 kg; 6 steers per pen) were transported either 8 (8H) or 18 (18H) h. Four 8H pens (n = 24 steers) and six 18H pens (n = 36 steers) were used for behavioral analysis. In both experiments, the time to eat, drink, and lay down was recorded for each steer upon return to home pens. Total pen displacements from the feed bunk were also assessed for the 2 h following feed access in both experiments. Data were analyzed using Proc Mixed of SAS 9.4, with treatment as a fixed effect. Steer was the experimental unit for behavioral activities, while pen was the experimental unit for bunk displacements. Displacements were analyzed as repeated measures with the repeated variable of time. In Experiment 1, the time to eat and drink was similar across treatments (P ≥ 0.17). However, TRANS laid down in 16.5 min while DEPR did not lay down until 70.5 min post-arrival to pen (P < 0.01). Deprived steers had greater bunk displacements in the first 70 min post-feed access than CON or TRANS, though displacements among treatments from 100 to 120 min post-feed access were similar (treatment × time: P = 0.02). In Experiment 2, both 8H and 18H steers laid down approximately 25 min post-home pen arrival (P = 0.14). There was no effect of transit duration or duration by time on bunk displacements (P ≥ 0.20), though displacements were greater from 0 to 20 min than from 20 to 30 min post-feed access (time: P = 0.04). Steers that were deprived of feed and water were highly motivated to access those resources, while transported steers prioritized laying down. Producers should consider these priorities when preparing to receive cattle from a long transit event.

Cotton cake as an economically viable alternative fibre source of forage in a high-concentrate diet for finishing beef cattle in feedlots.

Cotton cake can be a sustainable and economically viable alternative to maize silage as an effective fibre source in the finishing diet of feedlot beef cattle. Thus, the objective was to evaluate the economic viability and the productive performance of Nellore steers finished in feedlots using cotton cake as a source of fibre, replacing maize silage in the diet. Twenty-four non-castrated Nellore steers, with an average weight of 377.8kg and an age of approximately 24months, kept in individual pens, were used. The diet was 30% roughage, in the form of maize silage, and a diet without forage containing 30% cotton cake as an effective fibre source, based on dry matter. The design used was completely randomised with two treatments and 12 replications. Effects (p < 0.05) of the dietary fibre source were observed for final body weight (BW), total weight gain, hot carcass weight (HCW) and carcass yield (CY). Revenue and net margin were higher for the treatment with cotton cake. The corn silage diet promoted higher total costs per animal (U$ 408.41 vs. U$ 336.06) and daily costs (U$ 3.65 vs. U$ 3.00). Greater differences were observed between fibre sources for the concentrate cost, and the maize silage diet had a cost U$ 98.29 higher than the treatment with cotton cake (U$ 314.04 vs. U$ 215.75). The cotton cake treatment had a higher cost of U$106.98/animal for the net margin. Cotton cake is a viable alternative and can be used as a source of fibre in forage-free diets without affecting production performance, promoting benefits in economic performance for finishing beef steers in feedlots.

Stylosanthes silage as an alternative to reduce the protein concentrate in diets for finishing beef cattle

The objective of this study was to evaluate the effects of silage and concentrate on nutrients digestibility, ruminal fermentation, efficiency of nitrogen use and animal performance of feedlot beef cattle. Two experiments were conducted simultaneously evaluating the same diets. The forage: concentrate ratio was 50:50 and diets consisted of Stylosanthes (StS) or corn (CS) silages in combination with two concentrates: without (C1) or with soybean meal (C2). In experiment 1, four rumen and abomasum fistulated bulls with an average initial body weight (BW) of 200 ± 15.7 kg were distributed to a Latin square design with a 2 × 2 (S × C) factorial arrangement (experiment 1). Experiment 2 was conducted using 48 Nellore bulls with an average initial BW of 358 ± 30 kg, distributed to a complete randomized design with a 2 × 2 factorial arrangement and 12 replicates. In experiment 1, there was an S × C interaction tendency (P ≤ 0.09) for DM, OM, CP and NDF intakes. Greater intake of DM, OM, CP and NDF was observed for CS with C2. The intake of iNDF was greater (P = 0.01) for StS-based diets. There was a decrease tendency (P = 0.06) on the total CP digestibility in StS-based diets. Nitrogen balance was greater for CS-based diet (P = 0.04). There was an S × C interaction tendency (P = 0.10) for microbial synthesis efficiency (MSE). In experiment 2, C2-based diets showed greater (P < 0.01) intakes of DM, OM and CP. The average daily gain (ADG) and carcass average daily gain (CADG) were greater (P < 0.01) for diets containing the C2. Thus, it is concluded that StS can replace CS in diets of feedlot beef cattle. However, the concentrate source affects animal performance. Stylosanthes silage represents a sustainable alternative for animal production.

Effect of Using Aluminum Sulfate (Alum) as a Surface Amendment in Beef Cattle Feedlots on Ammonia and Sulfide Emissions

The objective of this study was to measure NH3 from feedlot surface material (FSM) containing aluminum sulfate (alum). A 33-day lab-scale study was conducted using pans containing FSM and either 0, 2.5, 5, or 10% alum. The pH of the FSM was significantly lower (p &lt; 0.01) when treated with 2.5, 5, and 10% alum as opposed to the 0% alum treatment. No NH3 volatilization occurred below a pH of 6.5. A second study determined that small, weekly doses of 5% alum did not lower NH3 emissions further than a single dose of 5% alum. Two studies on the feedlot surface demonstrated a significant decrease (p &lt; 0.01) in pH in the areas of the pens where alum was added compared to those that did not receive alum. Ammonia concentrations were lower (p &lt; 0.05) for the areas that received alum compared to those that did not receive alum for 7 days when 5% alum was applied and 14 days when 10% alum was applied. In all the studies, sulfide emissions increased when alum was added to the FSM. We concluded 10% alum may reduce NH3 emissions from beef feedlots temporarily, but higher sulfide emissions offset this benefit.

Pathways for avian influenza virus spread: GPS reveals wild waterfowl in commercial livestock facilities and connectivity with the natural wetland landscape.

Zoonotic diseases are of considerable concern to the human population and viruses such as avian influenza (AIV) threaten food security, wildlife conservation and human health. Wild waterfowl and the natural wetlands they use are known AIV reservoirs, with birds capable of virus transmission to domestic poultry populations. While infection risk models have linked migration routes and AIV outbreaks, there is a limited understanding of wild waterfowl presence on commercial livestock facilities, and movement patterns linked to natural wetlands. We documented 11 wild waterfowl (three Anatidae species) in or near eight commercial livestock facilities in Washington and California with GPS telemetry data. Wild ducks used dairy and beef cattle feed lots and facility retention ponds during both day and night suggesting use for roosting and foraging. Two individuals (single locations) were observed inside poultry facility boundaries while using nearby wetlands. Ducks demonstrated high site fidelity, returning to the same areas of habitats (at livestock facilities and nearby wetlands), across months or years, showed strong connectivity with surrounding wetlands, and arrived from wetlands up to 1251km away in the week prior. Telemetry data provides substantial advantages over observational data, allowing assessment of individual movement behaviour and wetland connectivity that has significant implications for outbreak management. Telemetry improves our understanding of risk factors for waterfowl-livestock virus transmission and helps identify factors associated with coincident space use at the wild waterfowl-domestic livestock interface. Our research suggests that even relatively small or isolated natural and artificial water or food sources in/near facilities increases the likelihood of attracting waterfowl, which has important consequences for managers attempting to minimize or prevent AIV outbreaks. Use and interpretation of telemetry data, especially in near-real-time, could provide key information for reducing virus transmission risk between waterfowl and livestock, improving protective barriers between wild and domestic species, and abating outbreaks.

Potential GHG emission benefits of Asparagopsis taxiformis feed supplement in Australian beef cattle feedlots

The red macroalgae Asparagopsis taxiformis has been identified as a promising feed supplement to inhibit enteric methane formation during ruminant livestock production and thereby contribute to GHG emissions reduction. Some studies also suggest improvements to animal weight gain through enhanced feed conversion efficiency. In this study, the potential GHG emissions reduction benefits were assessed from a life cycle perspective and in an actual industry context – the large Australian beef cattle sector, where feed supplementation occurred during feedlot finishing, when farmers have greatest control over animal diets. Seven adoption scenarios were compared to a baseline emissions inventory that was extrapolated to 2030. Feed supplementation with A. taxiformis had the potential to reduce the sector's carbon footprint by 1–4% in 2030, which due to the scale of the industry is a relevant emissions reduction (0.6–2.0 Mt CO2e), but modest in relation to the industry's goal of carbon neutrality by 2030. When emissions were assessed using alternative climate metrics that are more sensitive to changes in the rate of methane emission than the GWP100 climate metric (i.e. GWP*, radiative forcing climate footprint), larger potential benefits were found. Considering only the feedlot subsector, the radiative forcing climate footprint reached a plateau under most scenarios, indicating that climate neutrality is realistically achievable for the feedlot subsector within 5 years. That said, concurrent action on CO2 and N2O emissions will be needed, as even steep reductions in methane emissions at the expense of additional long-lived emissions will only achieve a short-term climate benefit and will make long-term climate stabilization more difficult.

Analysis of economic viability under risk conditions of a beef cattle feedlot system in São Paulo State, Brazil

Purpose: Assess the sensitivity and economic viability of the beef cattle feedlot system using as a reference a farm located in northern São Paulo State, Brazil.&#x0D; Methodology: A multidimensional approach was used to assess sensitivity. Financial results were analyzed in terms of cash flow using the net present value (NPV) as a viability indicator. Risks were incorporated using Monte Carlo simulations, considering feed, animal purchase, and animal selling prices as discrete random variables. The value measure was NPV, calculated using a minimum attractive rate of return of 7.55% per semester. Probabilities were estimated by relative frequency analysis.&#x0D; Results: The probability of a feedlot being economically attractive was 30.2%, indicating that the system was not viable in 69.8% of the cases. Sensitivity analysis showed that the feedlot was most vulnerable to fluctuations in selling price (a 1% increase in fed cattle price generated a 46% increase in NPV), followed by feeder cattle price (a 1% increase in feeder cattle price led to a 29% reduction in NPV) and feed price (a 1% increase in feed price produced a 12% reduction in NPV).&#x0D; Contributions of the Study: The findings of this study may support new evaluations in representative samples, complement previous studies on the topic, and assist decision makers.

Atmospheric Deposition of Particulate Matter from Beef Cattle Feedlots is a Likely Contributor of Pyrethroid Occurrence in Isolated Wetland Sediment: Source Apportionment and Ecological Risk Assessment

Atmospheric Deposition of Particulate Matter from Beef Cattle Feedlots is a Likely Contributor of Pyrethroid Occurrence in Isolated Wetland Sediment: Source Apportionment and Ecological Risk Assessment

Population-level analysis of antibiotic use and death rates in beef feedlots over ten years in three cattle-feeding regions of the United States.

To assess antibiotic use and other factors associated with death rates in beef feedlots in 3 regions of the US over a 10-year period. Data for 186,297 lots (groups) of finished cattle marketed between 2010 and 2019 were obtained from a database representing feedlots in the central, high, and north plains of the US. Descriptive statistics were generated. Generalized linear mixed models were used to estimate lot death rates for each region, sex (steer or heifer), and cattle origin (Mexico or the US) combination. Death rate was calculated as the (number of deaths/number of cattle placed in the lot) × 100. Lot antibiotic use (TotalActiveMG/KGOut) was calculated as the total milligrams of active antibiotics assigned to the lot per live weight (in kilograms) of cattle marketed from the lot. Rate ratios were calculated to evaluate the respective associations between lot death rate and characteristics of cattle and antibiotic use. Mean death rate increased during the 10-year period, peaking in 2018. Mean number of days on feed also increased over time. Mean TotalActiveMG/KGOut was greatest in 2014 and 2015, lowest in 2017, and moderated in 2018 and 2019. Death rate was positively associated with the number of days on feed and had a nonlinear association with TotalActiveMG/KGOut. Feeding medicated feed articles mitigated death rate. Results suggested a balance between disease prevention and control in feedlots for cattle with various risk profiles. Additional data sources are needed to assess TotalActiveMG/KGOut across the cattle lifetime.