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.
Global demand for livestock products is rising, resulting in a growing demand for feed and potentially burdening freshwater resources to produce this feed. To offset this increased pressure on water ...resources, the environmental performance of livestock sector should continue to improve. Over the last few decades, product output per animal and feedstuff yields in the US have improved, but before now it was unclear to what extent these improvements influenced the water productivity (WP) of the livestock products. In this research, we estimate changes in WP of animal products from 1960 to 2016. We consider feed conversion ratios (dry matter intake per head divided by product output per head), feed composition per animal category, and estimated the water footprint of livestock production following the Water Footprint Network's Water Footprint Assessment methodology. The current WP of all livestock products appears to be much better than in 1960. The observed improvements in WPs are due to a number of factors, including increases in livestock productivity, feed conversion ratios and feed crop yields, the latter one reducing the water footprint of feed inputs. Monogastric animals (poultry and swine) have a high feed-use efficiency compared to ruminants (cattle), but ruminants consume relatively large portion of feed that is non-edible for humans. Per unit of energy content, milk has the largest WP followed by chicken and pork. Per gram of protein, poultry products (chicken meat, egg and turkey meat) have the largest WP, followed by cattle milk and pork. Beef has the smallest WP. These data provide important information that may aid the development of strategies to improve WP of the livestock sector.
•Over the last few decades, product output per head of animal have increased.•Increase in the yield of feedstuffs has helped to lower the water footprint of feeds.•Water productivity of livestock products has improved between 1960 and 2016.•Water footprint of livestock production has decreased by 36% between 1960 and 2016.•Choosing feed ingredients and sourcing wisely will improve water productivity.
In light of recent host-microbial association studies, a consensus is evolving that species composition of the gastrointestinal microbiota is a polygenic trait governed by interactions between host ...genetic factors and the environment. Here, we investigated the effect of host genetic factors in shaping the bacterial species composition in the rumen by performing a genome-wide association study. Using a common set of 61,974 single-nucleotide polymorphisms found in cattle genomes (n = 586) and corresponding rumen bacterial community composition, we identified operational taxonomic units (OTUs), Families and Phyla with high heritability. The top associations (1-Mb windows) were located on 7 chromosomes. These regions were associated with the rumen microbiota in multiple ways; some (chromosome 19; position 3.0-4.0 Mb) are associated with closely related taxa (Prevotellaceae, Paraprevotellaceae, and RF16), some (chromosome 27; position 3.0-4.0 Mb) are associated with distantly related taxa (Prevotellaceae, Fibrobacteraceae, RF16, RFP12, S24-7, Lentisphaerae, and Tenericutes) and others (chromosome 23; position 0.0-1.0) associated with both related and unrelated taxa. The annotated genes associated with identified genomic regions suggest the associations observed are directed toward selective absorption of volatile fatty acids from the rumen to increase energy availability to the host. This study demonstrates that host genetics affects rumen bacterial community composition.
Abstract
A synthesis of data including over 9,300 head of cattle and over 980 pen means was conducted to evaluate the effect of corn processing method, distillers grains type, oil removal from ...distillers, and dietary distillers concentration on cattle performance and total feeding costs under different historical price scenarios. The corn processing method was either steam-flaked corn, high-moisture or dry-rolled corn or a blend of the latter two and their effects on performance with and without distillers grains. Wet, modified, and dry distillers were analyzed as either full fat or de-oiled products in diets at various dietary concentrations with either corn type to determine cattle performance. Performance estimates were used to determine the inclusion level that minimized total finishing costs ($/head) for each diet given various assumptions on corn price, corn-to-distillers price ratio, supplemental protein cost, and steam flake processing cost. Feeding distillers grains in steam-flaked or high-moisture and dry-rolled corn diets resulted in improved feed conversion and reduced cattle feeding costs, including lower supplemental protein costs and lower total feeding costs compared with a diet without distillers. However, feeding diets with steam-flaked corn improved feed conversion regardless of distillers type or level of inclusion. Feeding full fat distillers improved feed conversion relative to de-oiled distillers. Cattle fed de-oiled distillers were more efficient than those fed diets containing no distillers grains. At all corn price and corn-to-distillers price ratios examined, feeding some level of distillers of any type produced a lower total feeding costs relative to a diet without distillers. Different robustness tests were conducted to determine the impact of varying steam flake corn processing costs and the cost of supplemental protein on the optimal level of distillers inclusion level. The break-even cost a producer could pay for steam-flaking corn varied but was significantly higher when corn price was high. Feeding distillers grains in steam-flaked or high-moisture and dry-rolled corn diets resulted in improved feed efficiency, reduced cattle feeding costs, including replacement of other supplemental protein and associated costs compared to a diet without distillers grains.
A synthesis of randomized control trial data determined feeding distillers grains in finishing diets improved feed conversions, reduced total finishing costs, reduced reliance on supplemental protein sources, and increased economic returns compared to feeding diets without distillers.
Lay Summary
A pooled analysis of research was conducted to evaluate the effect of corn processing method, distillers grains type, oil removal from distillers, and distillers inclusion on cattle performance within studies conducted at the University of Nebraska-Lincoln between 1992-2020. Two corn processing methods were included in the dataset, steam-flaked corn (SFC) or any combination of high-moisture (HMC) and dry-rolled corn (DRC), fed with and without distillers gains, a by-product of the dry milling ethanol industry. Distillers products were either wet, modified, or dry distillers grains plus solubles and were analyzed as both full fat and de-oiled products. Cattle performance resulting from feeding the six by-product combinations with both corn types was analyzed and then used to find the inclusion level that minimized the total feeding cost ($/head) given different corn prices and corn-to-distillers price ratios. Cattle had improved feed conversion when fed SFC compared with HMC:DRC in all diets. Cattle fed full-fat distillers grains had slightly improved feed conversions compared with de-oiled distillers grains. Cattle fed distillers grains diets had improved feed conversion compared with cattle fed control diets without distillers. Overall, feeding distillers grains in combination with either corn type offers benefits including improved feed conversions, lower finishing costs, and reduced reliance on supplemental protein sources compared to a diet without distillers.
Abstract
An experiment was conducted over 2 yr to measure performance and greenhouse gas (GHG) emissions of weaned calves from two cow-calf production systems. Crossbred steers and heifers (n = 270, ...initial body weight (BW) = 207 kg, SD = 35) were used in a randomized complete block design, with treatments applied to the cow-calf system. Treatments were: 1) a traditional system consisting of April to June calving with smooth bromegrass pasture and grazed corn residue as forage resources (TRAD); 2) an alternative system consisting of July to September calving utilizing partial-drylot feeding, summer-planted oats, and corn residue grazing (ALT). Calves from both production systems were weaned at the same age and grown (diet NEg = 1.05 Mcal kg–1) for approximately 117 d. The calves then transitioned to a high-grain finishing diet (year 1: NEg = 1.32 Mcal kg–1; year 2: NEg = 1.39 Mcal kg–1) and fed to a targeted 1.52 cm backfat. Growth performance in the grower phase resulted in greater (P < 0.01) average daily gain (1.39 vs. 1.22 ± 0.02 kg), greater gain:feed (P < 0.01; 0.157 vs. 0.137 ± 0.003) for ALT calves compared to TRAD calves, However, a lower initial BW (P < 0.01; 185 vs. 229 ± 4.9 kg) resulted in a lower ending BW (P < 0.01; 347 vs. 371 ± 2.9 kg) for ALT calves compared to TRAD calves in spite of improved growth performance. In the finisher phase, ALT calves gained less (1.52 vs. 1.81 ± 0.218 kg; P = 0.02), were less efficient (0.139 vs. 173 ± 0.0151; P = 0.01) but exhibited similar hot carcass weights (HCW) (388 vs. 381 ± 3.8 kg; P = 0.14) compared to TRAD calves. Each pen of calves was put into a large pen-scale chamber that continuously measured carbon dioxide (CO2) and methane (CH4) for 5 d during the grower and finisher phases. The average CH4 and CO2 production per unit of feed intake was used to calculate total GHG emissions over the entire grower and finisher phase. Overall, there were no differences (P ≥ 0.17) between treatments for CH4 per day and per kilogram dry matter intake (DMI). However, ALT calves tended to produce less (P ≤ 0.10) CO2 per day and per kilogram DMI than TRAD calves. Overall, methane emissions were greater in ALT calves (110.7 vs. 92.2 ± 8.3 g CH4 kg–1 HCW; P = 0.04) than TRAD calves. The ALT calves required 27 additional days on feed to market, which resulted in more total CH4 per animal across the entire feeding period (P = 0.02) than TRAD calves. Production systems that reduce days to market to achieve similar HCW may reduce GHG emissions.
Beef calves raised in intensive cow-calf production systems encounter different physiological and environmental challenges than calves raised in traditional, extensive cow-calf production systems. This research examined the effects of a partial-intensive and extensive cow-calf production system on post-weaning calf growth and greenhouse gas emissions. Compared to calves from the extensive cow-calf system, calves raised in the partial-intensive cow-calf system required an additional 27 d on feed to reach the targeted backfat thickness before harvest, and produced more total methane and CO2.
Lay Summary
There are many reasons (i.e. drought, limited perennial forage, calving) for using intensive or partially intensive production practices (e.g. drylotting or confinement) in a cow-calf enterprise. These practices may impact subsequent calf growth and feedlot performance. In addition, limited data are available comparing the environmental impacts (i.e., greenhouse gas (GHG) emissions) from different cow-calf production systems. This experiment evaluated the effects of a partial-intensive cow-calf production system on post-weaning calf growth performance, carcass characteristics, and GHG emissions. Calves from the partial-intensive cow-calf system had improved growth compared to calves from the extensive cow-calf system during the grower phase. During finishing, calves from the partial-intensive cow-calf system had poorer growth performance resulting in calves from the partial-intensive cow-calf system requiring an additional 27 d on feed to reach finish as calves from the traditional cow-calf system. These differences are likely due to compensation from lower gain periods resulting in better gain in the subsequent growth period. Cow-calf production system did not alter methane and carbon dioxide emissions per kilogram of intake. However, because calves in the partial-intensive cow-calf system required additional days on feed, absolute methane and carbon dioxide emissions were greater per animal for the partial-intensive cow-calf system compared to the extensive cow-calf system suggesting that reducing days to market may reduce emissions from beef systems.
Abstract
A pooled analysis was performed to evaluate whether corn silage fed at 15% or 45% of diet DM impacted liver abscesses prevalence at slaughter in five previous experiments. Cattle fed 15% ...corn silage had 7.8% abscessed livers compared to 4.1% for cattle fed 45% corn silage when all diets contained tylosin. While improved due to increased corn silage inclusion, the objective of the current finishing study was to determine the impact of silage inclusion in finishing diets with and without tylosin on performance and incidence of abscessed livers in beef cattle. A total of 640 (BW = 334 ± 25 kg) steers were used in a generalized randomized block design with a 2 × 2 factorial treatment design. Treatments included two concentrations of corn silage (15% and 45% of diet DM), with or without tylosin for liver abscesses. This study used 32 pens of cattle with 20 steers per pen and 8 pens per treatment. There was a tendency for an interaction for feed efficiency (G:F; P = 0.10) where cattle fed 15% corn silage had a 2% increase in G:F when tylosin was added to the diet, but no improvements in G:F were observed when tylosin was added to diets containing 45% silage. There was an interaction between silage and tylosin inclusion for abscessed livers (P = 0.05). Cattle fed 15% corn silage without tylosin had the greatest incidence of abscessed livers (34.5%) compared to other treatments (P = 0.05), and the incidence of abscessed livers was decreased to 19% if tylosin was fed with 15% corn silage. Feeding 45% silage was effective at lowering the incidence of abscessed livers (P = 0.05) which was 12.4%, regardless of whether tylosin was fed. Feeding corn silage at 45% of diet DM (77.5% concentrate) was as effective as feeding tylosin to cattle on a 92.5% concentrate diet. Feeding corn silage at greater inclusions decreased daily gain (P ≤ 0.01) but increased final body weight when fed to an equal fatness (cattle fed 45% CS were fed 28 d longer). Feeding corn silage at 45% was more economical compared to feeding 15% corn silage, especially as corn prices increase, provided shrink is well managed. Feeding elevated concentrations of corn silage may be an economically viable method to reduce incidence of liver abscesses without antibiotic use for smaller operations that can manage more corn silage in finishing diets.
Elevating corn silage inclusion from 15% to 45% in the diet decreased abscessed livers which may be one alternative to the use of antibiotics. Performance measures worsen as inclusion increases but corn silage proves to be an economical roughage source.
Lay Summary
Antibiotics are a very effective method to control liver abscesses for finishing cattle, which are thought to be due to high starch concentration and acidosis. Dietary roughage (forage) is used to control acidosis. As grain prices increase, feeding greater amounts of corn silage may be advantageous and silage can be an economical forage compared to other traditional forages like alfalfa. This study evaluated the impact of corn silage inclusion on performance and abscessed livers with and without the addition of antibiotics. As expected, feeding more corn silage decreased both gain and feed efficiency but also increased profitability. Feeding tylosin with a traditional inclusion of silage (15%) decreased abscessed livers from 34.5% to 19%. However, if cattle are fed more silage (45%) the incidence of abscessed livers was 12.4%, regardless of feeding tylosin or not.
Abstract
Calf-fed Holstein steers (n = 115; 449 ± 20 kg) were utilized in a serial harvest experiment. A baseline group of five steers was harvested after 226 d on feed (DOF), which was designated ...day 0. The remaining cattle were assigned randomly to 11 harvest groups, with slaughter every 28 d. Cattle were either not (CON) or were fed zilpaterol hydrochloride for 20 d followed by a 3 d withdrawal (ZH). There were five steers per treatment in each slaughter group ranging from days 28 to 308. Whole carcasses were divided into lean, bone, internal cavity, hide, and fat trim components. Apparent mineral retention (Ca, P, Mg, K, and S) within the body was calculated as the difference between mineral concentration at slaughter and day 0. Mineral concentration at day 0 was determined from body composition of steers harvested at day 0 multiplied by individual live body weight (BW) at day 0. All data were analyzed as a 2 × 11 factorial arrangement with individual animal as the experimental unit. Orthogonal contrasts were used to analyze linear and quadratic contrasts over time (11 slaughter dates). There were no differences in concentration of Ca, P, and Mg in bone tissue as feeding duration increased (P ≥ 0.89); concentration of K, Mg, and S in lean tissue did fluctuate across DOF (P < 0.01). Averaged across treatment and DOF, 99% of Ca, 92% of P, 78% of Mg, and 23% of S present in the body were in bone tissue; 67% of K and 49% of S were in lean tissue. Expressed as gram per day, apparent retention of all minerals decreased linearly across DOF (P < 0.01). Expressed relative to empty body weight (EBW) gain, apparent Ca, P, and K retention decreased linearly as BW increased (P < 0.01) whereas Mg and S increased linearly (P < 0.01). Apparent retention of Ca was greater for CON cattle (greater bone fraction) and apparent retention of K was greater for ZH cattle (greater muscle fraction) when expressed relative to EBW gain (P ≤ 0.02), demonstrating the increase in lean gain by ZH cattle. There were no differences in apparent retention of Ca, P, Mg, K, or S due to treatment (P ≥ 0.14) or time (P ≥ 0.11) when expressed relative to protein gain. Apparent retention averaged 14.4 g Ca, 7.5 g P, 0.45 g Mg, 1.3 g K, and 1.0 g S/100 g protein gain. Expressing apparent mineral retention on a protein gain basis minimized effects of rate and type of gain, allowing for better comparison across treatments and time. Feeding zilpaterol hydrochloride did not affect apparent mineral retention when expressed relative to protein gain.
This research measured concentration of Ca, P, Mg, K, and S in the body of Holstein steers across a 308-d feeding duration, relative to a control group harvested on day 0. Previously established feedlot cattle requirements for these minerals are primarily based on serial harvest data from the 1940s.
Lay Summary
Mineral requirements for feedlot cattle are largely based on measured mineral concentration in the body at harvest. Fairly extensive research has been done quantifying Ca and P in the body of cattle, but data on Mg, K, and S are sparse. Serial harvest experiments are expensive and labor intensive and therefore not conducted frequently. A group of 115 Holstein steers was fed a finishing diet with serial harvest every 28 d. Two treatments were evaluated, control and cattle fed zilpaterol hydrochloride to increase lean tissue growth. Every 28 d, five steers from each treatment group were harvested with the whole carcass divided into lean, bone, internal cavity, hide, and fat trim components. Apparent mineral retention was calculated as the difference between mineral composition at day 0 (baseline harvest group) and each 28 d harvest group. Averaged across treatment and days on feed, 99% of Ca, 92% of P, 78% of Mg, and 23% of S present in the body were measured in bone tissue; 67% of K and 49% of S were in lean tissue. Apparent retention averaged 14.4 g Ca, 7.5 g P, 0.45 g Mg, 1.3 g K, and 1.0 g S/100 g protein gain.
Abstract
Two experiments were conducted to evaluate the effect of different corn milling methods for high-moisture and dry corn on finishing cattle performance, carcass traits, and nutrient ...digestion. In experiment 1, steers (N = 600 60 pens; initial body weight BW = 402 ± 17 kg) were fed for 134 d to evaluate the effect of milling method and corn type on performance and carcass characteristics. Treatments were evaluated as a 2 × 3 factorial design with factors being milling method (Automatic Ag roller mill ROLL or hammer mill HAMMER) and corn type (high-moisture HMC, dry DC, or 50:50 blend of HMC and DC BLEND). There were no milling method × corn type interactions for final BW, gain (ADG), or dry matter intake (DMI; P ≥ 0.32), but there tended to be an interaction for G:F (P = 0.09). Cattle fed ROLL HMC had 4.7% greater gain:feed (G:F; P ≤ 0.01) with 55% lower fecal starch (P < 0.01) compared to HAMMER HMC, whereas processing did not impact (P = 0.74) G:F in DC diets. There were no further effects (P ≥ 0.14) on performance or carcass traits regardless of milling method or corn type. In experiment 2, seven ruminally fistulated steers were utilized in a 4 × 7 incomplete Latin rectangle to evaluate the effects of DC or HMC processed with either ROLL or HAMMER (2 × 2 factorial treatment design) on nutrient digestion. Feeding HMC decreased the amount of excreted dry matter (DM) and organic matter (OM; P ≤ 0.01) regardless of mill type, but there was a tendency (P ≤ 0.13) for an interaction between corn type and mill type for DM and OM digestibility. There was no difference between milling treatments fed as HMC (P ≥ 0.69), but the HAMMER DC diet was more digestible than the ROLL DC (P = 0.05). As expected, HMC-based diets had greater (P < 0.01) starch digestibility compared to DC, but milling method had no impact on starch digestibility (P = 0.56). There were no differences (P = 0.56) in average ruminal pH, but HMC diets had greater variance (P = 0.04) and greater area less than pH 5.6 (P = 0.05) compared to DC based diets while milling method did not impact either (P > 0.33). Processing HMC with a roller mill improved G:F compared to processing with a hammer mill, but had little effect when corn was fed as dry corn or HMC:DC blend. Furthermore, feeding cattle HMC compared to DC increases nutrient digestibility, but milling method had little impact.
Using a roller mill improved feed efficiency of feedlot cattle when using high-moisture corn compared to a hammer mill, but milling type did not impact performance when processing dry corn. Digestion was improved for high-moisture compared to dry corn, but also increased risk of ruminal acidosis.
Lay Summary
Two experiments tested how processing of corn grain for finishing cattle influences growth performance and nutrient digestion. Producers can use corn in dry or high-moisture form but normally use either a hammer mill or roller mill. When using high-moisture corn, we observed a 5% improvement in gain:feed (G:F) for rolling as compared to hammer milling, which is likely due to more uniform particle size and improved digestion. Unlike the performance study, milling method did not impact digestion for high-moisture corn. Using a hammer-mill for dry corn improved digestion compared to rolling which was not supported by improved performance in the finishing study. Using high-moisture corn increases risk of ruminal acidosis compared to dry corn, but also improves feed efficiency if acidosis can be minimized.
Beef cattle feedlots are estimated to contribute 26% of U.S. agricultural greenhouse gas (GHG) emissions, and future climate change policy could target reducing these emissions. Life cycle assessment ...(LCA) of GHG emissions from U.S. grain-fed beef cattle was conducted based on industry statistics and previous studies to identify the main sources of uncertainty in these estimations. Uncertainty associated with GHG emissions from indirect land use change, pasture soil emissions (e.g. soil carbon sequestration), enteric fermentation from cattle on pasture, and methane emissions from feedlot manure, respectively, contributed the most variability to life cycle GHG emissions from beef production. Feeding of coproducts from ethanol production was estimated to reduce life cycle emissions by 1.7%, but could increase emissions by 0.6–2.0% with higher feeding rates. Monte Carlo simulation found a range of life cycle emissions from 2.52 to 9.58 kg CO2 per kg live weight (5th and 95th percentiles), with a calculated average of 8.14, which is between recent estimates. Current methods used by the U.S. Environmental Protection Agency (EPA) associated with beef production in feedlots were found to account for only 3–20% of life cycle GHG emissions.
•Life cycle emissions from beef cattle can vary dramatically with factors identified.•Feeding of ethanol coproducts reduces life cycle emissions by 1.7% on average.•Monte Carlo simulation found average life cycle emissions of 8.14 kg CO2 per kg.•Methods of the U.S. EPA account for only 3–20% of life cycle GHG emissions.
Abstract
A 2-yr study (year 1: March to September 2017; year 2: February to August 2018) was conducted using crossbred steers (year 1: n = 1677; initial body weight BW = 372 kg, SD = 47; year 2: n = ...1713; initial BW = 379 kg, SD = 10) in a commercial feedyard study in Eastern NE to determine the effects of shade on cattle performance, ear temperature, and cattle activity. Two treatments were evaluated using a randomized complete block design (n = 5 blocks based on arrival). Treatments were assigned randomly to pens and consisted of five pens without shade (NO SHADE) and five pens with shade (SHADE). Ear temperatures were collected throughout the trials using biometric sensing ear tags on a subset of cattle. Panting scores were collected using a 5 point scale determined visually based on the level of panting occurring on the same subset of steers a minimum of twice weekly from June 8 to August 21 in year 1 and May 29 to July 24 in year 2 by one trained individual each year. In year 1, no differences (P ≥ 0.24) were observed for growth performance or carcass characteristics. Dry matter intake (DMI) and average daily gain (ADG) were greater (P ≤ 0.04) for SHADE cattle in year 2. Over the entire feeding period in year 1, greater (P < 0.01) ear temperature was observed for NO SHADE cattle, but cattle movement was not different (P = 0.38) between treatments. When evaluating the entire feeding period in year 2, cattle movement and ear temperature were not different (P ≥ 0.80) between treatments. Cattle in the SHADE treatment had lower (P ≤ 0.04) panting scores in years 1 and 2. These data suggest that providing shade can lessen the negative influence of heat events on DMI and was an effective way to reduce heat stress in feedlot operations, but only impacted ADG if heat events were close to the cattle slaughter date.
When cattle were exposed to heat stress during finishing, dry matter intake, and average daily gain were reduced when stress occurred close to marketing date, but not when marketed after a recovery period, as determined over two consecutive years. Panting, ear temperature, and pen surface temperatures were improved by providing shade, which may improve cattle growth performance.
Lay Summary
This study was performed over two separate summers to evaluate natural exposure to heat and quantify the impact that providing shade has on stress measures, estimates of body temperature, and feedlot performance. In the first year, cattle were marketed after summer heat events and while ear temperature and panting scores were decreased for cattle in shaded pens, the effect was not significant enough to influence performance parameters. In the second year when cattle were marketed more immediately following heat impacts, cattle fed in shaded pens consumed more feed and gained more weight than cattle fed in pens without shade. In both years, cattle decreased dry matter intakes to offset normal heat events.
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