Grass-finished Beef Research Articles

Fatty acids and secondary metabolites can predict grass-finished beef and supplemental cattle feeds

Beef raised using rotational grazing practices on biodiverse pastures offers potential benefits to animal and environmental health and can improve the nutrient density of meat to favor human health. However, many cattle producers contend with the seasonal unavailability of fresh forage, necessitating the utilization of supplementary feeds or indoor feeding. The objective of this study was to profile secondary metabolites and fatty acids in grass-finished beef supplemented with different feeds (4.5 kg/head/day) and to explore the potential for grass-finished beef authentication. In this two-year study, steers (n = 115) were randomly allocated to one of four diets: 1) pastured/supplemented with hay (control group), 2) pastured/supplemented with baleage, 3) pastured/supplemented with soybean hulls, or 4) baleage/soybean hulls in confinement. Secondary metabolites and fatty acids were measured using UHPLC-MS/MS and GC-MS, respectively. Of the 94 measured metabolites, pyridoxine, alpha-tocopherol, hippuric acid, and gallic acid differed between diets (p < 0.05 for all). Based on random forest classification, beef from the pasture/hay, pasture/baleage, pasture/soybean hulls, and confinement baleage/soybean hulls groups could be identified with a predictive accuracy of 100%, 50%, 41%, and 97%, respectively. Although minimal significant differences were observed, our data indicate that certain supplemental feeds maintain favorable nutritional profiles of grass-finished beef. In addition, metabolomics can predict cattle on exclusively forage-based or feed-based diets with a high degree of certainty.

Climate impacts of alternative beef production systems depend on the functional unit used: Weight or monetary value

Beef production has been identified as a significant source of anthropogenic greenhouse gas (GHG) emissions in the agricultural sector. United States and Canada account for about a quarter of the world's beef supply. To compare the GHG emission contributions of alternative beef production systems, we conducted a meta-analysis of 32 studies that were conducted between 2001 and 2023. Results indicated that GHG emissions from beef production in North America varied almost fourfold from 10.2 to 37.6 with an average of 21.4 kg CO2e/kg carcass weight (CW). Studies that considered soil C sequestration (C-seq) reported the highest mitigation potential in GHG emissions (80%), followed by growth enhancement technology (16%), diet modification (6%), and grazing management improvement (7%). Our study highlights the implications of using carbon intensity per economic activity (i.e., GHG emissions per monetary unit), compared to the more common metric of intensity on per weight of product basis (GHG emissions per kg CW) for comparisons across differentiated beef cattle products. While a positive association was found between the proportion of lifespan on grassland and the conventional weight-based indicator, grass-finished beef was found to have lower carbon intensity per economic activity than feedlot-finished beef. Our study emphasizes the need to incorporate land use and management effects and soil C-seq as fundamental aspects of beef GHG emissions and mitigation assessments.

Measuring the Phytochemical Richness of Meat: Effects of Grass/Grain Finishing Systems and Grapeseed Extract Supplementation on the Fatty Acid and Phytochemical Content of Beef.

Grass-finished beef (GFB) can provide beneficial bioactive compounds to healthy diets, including omega-3 polyunsaturated fatty acids (n-3 PUFAs), conjugated linoleic acid (CLA), and secondary bioactive compounds, such as phytochemicals. The objective of this study was to compare fatty acids (FAs), micronutrients, and phytochemicals of beef fed a biodiverse pasture (GRASS), a total mixed ration (GRAIN), or a total mixed ration with 5% grapeseed extract (GRAPE). This was a two-year study involving fifty-four Red Angus steers (n = 54). GFB contained higher levels of n-3 PUFAs, vitamin E, iron, zinc, stachydrine, hippuric acid, citric acid, and succinic acid than beef from GRAIN and GRAPE (p < 0.001 for all). No differences were observed in quantified phytochemicals between beef from GRAIN and GRAPE (p > 0.05). Random forest analysis indicated that phytochemical and FA composition of meat can predict cattle diets with a degree of certainty, especially for GFB (5.6% class error). In conclusion, these results indicate that GFB contains higher levels of potentially beneficial bioactive compounds, such as n-3 PUFAs, micronutrients, and phytochemicals, compared to grain-finished beef. Additionally, the n-6:n-3 ratio was the most crucial factor capable of separating beef based on finishing diets.

Grass finishing of Criollo cattle can provide an environmentally preferred and cost effective meat supply chain from United States drylands

CONTEXTThe southwestern United States is experiencing an increasingly warmer and drier climate that is affecting cattle production systems of the region. Adaptation strategies are needed that will not compromise environmental quality or profitability. Options include the use of desert-adapted beef cattle biotypes, such as Rarámuri Criollo cattle, and crossbreds of Criollo with more traditional British breeds. Currently, most calves raised in the Southwest are grain finished, often with irrigated crops produced in the hydrologically-threatened Ogallala Aquifer region. A viable alternative may be grass finishing with the rainfed forage of the arid and semi-arid rangeland of the Southwest or in the temperate grasslands of the Northern Plains. OBJECTIVECompare the environmental impacts and production costs of grain-finishing in Texas and grass-finishing in the Northern plains and the Southwest with traditional Angus cattle vs. Criollo and Criollo x Angus cattle. METHODSNine supply chain strategies were simulated using the Integrated Farm System Model to compare farm-gate life cycle intensities of greenhouse gas emissions (carbon footprint), fossil energy footprint, nitrogen footprint, blue water footprint and production costs using representative (appropriate soils, climate, and management) ranch and feedlot operations. RESULTS AND CONCLUSIONSFor both finishing options (grass, grain), Criollo x Angus cattle had the best environmental (3%–27% lower), and production cost (4–23% lower) outcomes followed by pure Criollo and then Angus cattle. Crossbred production combined the lower feed supplementation requirements of Criollo cows with heavier final carcasses of offspring from Angus genetics. Crossbred cattle with grass finishing in the Southwest or Northern Plains outperformed on most environmental variables as well as production costs, mostly due to reduced external input requirements (primarily feed). A downside for grass-finished crossbreds was greater carbon footprint (27–42% higher) compared to grain finishing due to greater methane emissions from high forage diets and an extended time to finish. On grasslands where soil C sequestration can be supported, that land-based sequestration may offset the greater greenhouse gas emission from enteric methane of grass-finished beef. Grass finishing in the Northern Plains may provide a more reliable meat supply chain than grass finishing in the Southwest due to the lower risk and less severe consequences of drought. SIGNIFICANCEAlternative beef supply chain options using Rarámuri Criollo cattle were found to be sustainable production systems that can be adopted by ranchers in the southwestern United States to adapt to the changing climate.

Effects of Hay, Baleage, and Soybean Hulls Waste Used as Supplemental Feeds on the Nutritional Profile of Grass-Finished Beef.

Grass-finished beef (GFB) has demonstrated wide nutritional variations with some GFB having a considerably higher n-6:n-3 ratio compared to grain-finished beef. To better understand these variations, the current study investigated the effects of commonly used supplemental feeds on the nutritional profile of GFB. This two-year study involved 117 steers randomly allocated to one of four diets: (1) grass+hay (G-HAY), (2) grass+baleage (G-BLG), (3) grass+soybean hulls (G-SH), and (4) baleage+soybean hulls in feedlot (BLG-SH). Feed samples were analyzed for their nutritional value, and beef samples underwent analysis for fatty acids (FAs), vitamin E, minerals, lipid oxidation, and shear force. FAs were measured by GC-MS, vitamin E was analyzed chromatographically, minerals were analyzed by ICP-MS, and lipid oxidation was measured via a thiobarbituric acid reactive substances (TBARS) assay. G-SH beef had the highest n-6:n-3 ratio (p < 0.001), while BLG-SH beef contained less vitamin E (p < 0.001) and higher TBARS values (p < 0.001) compared to the other groups. G-HAY beef contained more long-chain n-3 polyunsaturated FAs compared to the other groups (p < 0.001). In conclusion, G-HAY beef had the most beneficial nutritional profile, while soybean hulls increased the n-6:n-3 ratio of beef.

Fatty Acid and Micronutrient Profile of Longissimus Lumborum from Red Angus and Red Angus x Akaushi Cattle Finished on Grass or Grain.

Cattle diet and breed modify the nutritional profile of beef. The objective of this study was to compare the fatty acid (FA) and micronutrient profiles of Red Angus (RA) and RA x Akaushi (AK) crossbreed steers fed either a grass or grain diet. This two-year study randomly assigned steers to the diets using a 2 × 2 factorial experiment. FAs and micronutrients were analyzed. Diet effect was the strongest with grass-finished beef being higher in n-3 polyunsaturated FAs (p &lt; 0.001), conjugated linoleic acid (p &lt; 0.05), vaccenic acid (p &lt; 0.05), iron (p &lt; 0.001), and vitamin E (p &lt; 0.001) compared to grain-finished beef. Breed effects were observed for lauric and myristic acids (p &lt; 0.05), selenium (p &lt; 0.05), and zinc (p &lt; 0.01) with AK containing more of these compounds than RA. Diet × breed effects were non-existent. These results indicate that diet has a stronger influence than breed on modifying the nutritional profile of beef. Because of a more favorable FA and antioxidant profile, consumption of grass-finished beef could benefit human health.

Attention to the Details: How Variations in U.S. Grass-Fed Cattle-Feed Supplementation and Finishing Date Influence Human Health

As the global population increases, so does meat consumption. This trend is accompanied by concerns regarding the meat industry, and consumers are demanding transparency on the environmental and health effects of the products they are purchasing. Many leading health organizations recommend reducing red meat consumption. Nevertheless, no differentiation is made among red meats and beef. The beef production system is generally ignored despite nutritional differences between grain- and grass-fed beef. Compared to grain-fed beef, grass-fed beef contains a healthier fatty acid profile, including more omega-3 polyunsaturated fatty acids and conjugated linoleic acid, and increased concentrations of phytochemicals desired by health-conscious customers. However, there is a lack of consistency among grass-fed beef in the United States regarding clear product labeling and cattle dietary components. Grass-fed beef labeling confusion has emerged, including misunderstandings between grass-fed and grass-finished beef. Along with this, previous studies observed significant nutritional variation among grass-finished beef from different producers across the country. Cattle diet has the strongest influence on the nutritional composition of beef. Therefore, understanding differences in feeding practices is key to understanding differing nutritional quality of grass-fed beef. Feeding cattle diverse pastures composed of multiple plant species including grasses and legumes managed in a rotational grazing fashion results in higher omega-3 polyunsaturated fatty acids and phytochemical levels in beef compared to feedlots and monocultures. Seasonal differences including changes in temperature, rainfall, grazing practices, and plant growth cycles affect the nutritional composition of feeds and ultimately meat. Additional feeds utilized in grass-fed beef production systems such as conserved forages may reduce or increase health-promoting nutrients in grass-fed beef, while supplements such as grape byproducts and flaxseed may improve its nutritional profile. Further research should measure the effects of individual feedstuff and the finishing period on the nutritional profile on grass-fed beef. A better understanding of these details will be a step toward the standardization of pasture-raised ruminant products, strengthening the relationship between grass-fed beef consumption and human health.

Palatability of high-quality New Zealand grass-finished and American grain-finished beef strip steaks

The objective of this study was to evaluate palatability of strip loin steaks from grass- and grain-fed beef across five United States Department of Agriculture (USDA) quality grades and three wet aging periods. Beef strip loins (N = 200; 20 per USDA quality grade/fed cattle type) representing five USDA quality grades [USDA Prime, Top Choice (Average and High Choice), Low Choice, Select and Standard] and two fed cattle types [New Zealand grass-finished and United States (U.S.) grain-finished] were used in the study. Each strip loin was equally portioned into thirds and randomly assigned to one of three wet aging periods (7 d, 21 d or 42 d). Consumer panelists (N = 600; 120/location: Texas, California, Florida, Kansas, and Pennsylvania) evaluated eight grilled beef steak samples for palatability traits, acceptability, and eating quality. All palatability traits were impacted by the interaction of diet × quality grade (P &amp;lt; 0.05). Although similar (P &amp;gt; 0.05) to grass-fed Prime steaks for juiciness, tenderness and overall liking, grain-fed Prime steaks rated greater (P &amp;lt; 0.05) than all other grass- and grain-finished treatments for all palatability attributes. Grass-finished Top Choice, Low Choice, and Standard steaks were rated greater (P &amp;lt; 0.05) than the respective grain-finished quality grades for juiciness and tenderness. Grain-finished Standard steaks rated lower (P &amp;lt; 0.05) than all other grass- and grain-finished treatments for juiciness, tenderness, and overall liking; but were similar (P &amp;gt; 0.05) to grass-finished Standard steaks for flavor liking. Our results indicate beef strip loin steaks of similar quality grades from grass-finished New Zealand cattle produce similar eating experiences when compared to those from U.S. grain-finished beef, even following extended post-mortem aging. This indicates improved palatability for consumers based on marbling without respect to grass- or grain-finishing diets.&amp;nbsp;

Seasonal differences exist in the polyunsaturated fatty acid, mineral and antioxidant content of U.S. grass-finished beef

There is increased consumer interest in grass-finished beef (GFB) with retail sales reaching $272 million in 2016. GFB contains higher omega-3 fatty acid levels compared to grain-finished beef, but variations in fatty acid (FA), mineral, and antioxidant content by producers and season is poorly documented. Hence, GFB samples from cattle finished in both fall and spring were obtained from four producers representing several US sub-regions. FAs were extracted using microwave-assisted extraction, derivatized to methyl-esters, and quantified using gas chromatography-mass spectrometry. Mineral content was quantified using coupled plasma mass-spectrometry and antioxidants were quantified via UV-absorption. Overall, total omega-3 FA content was greater in beef from cattle finished in the spring (13.4 mg/100g beef) than the fall (10.3; P<0.001). Additionally, α-tocopherol was present in greater amounts in spring-finished beef (259 vs. 223 ug/100g beef, P<0.001) as was the micromineral selenium (18.2 vs. 17.3ug/100g beef, P = 0.008). Despite using the same feed in fall and spring, cattle from producer 4 had higher total omega-3, omega-6, and total polyunsaturated fatty acids in spring compared to fall (P<0.010). These results suggest there are seasonal differences in omega-3 and omega-6 fatty acids, minerals and antioxidants in grass-finished beef independent of finishing diet.

PSV-30 A nutritional survey of commercially available grass-finished beef

Abstract Consumer interest in the source of their food, its environmental footprint, and the impact of diet on health has supported the growth of the grass-finished beef (GFB) industry. Studies have concluded that GFB has distinct nutritional differences from conventionally-finished beef. As the GFB industry continues to expand, it is vital to continue to explore the nutritional complexities and variation in the product. To achieve this, a survey of grass-finishing production systems throughout the United States was conducted, and beef finished on the participating farms was analyzed for its nutritional composition, including fatty acid (FA), mineral and fat-soluble vitamin contents. Samples were analyzed from 12 producers and annual production capacity of farms ranged from 25 to 5,000 cattle, with a mean age of cattle at harvest of 26.8 ± 2.30 mo. An array of finishing diets included grazing exclusively in perennial pasture, incorporating annual forage crops, and feeding a variety of harvested forages with supplementation of non-starch feed byproducts. Beef muscle tissue FA content was analyzed by gas chromatography-mass spectrometry (GC–MS). The mean ratio of omega-6 (n-6) to omega-3 (n-3) FA in samples varied significantly by producer, ranging from 1.80 to 28.3 (P &amp;lt; 0.0001), with an overall sample set median of 4.10. A selection of minerals including iron, magnesium, and potassium were analyzed by ICP emission spectroscopy and mineral content significantly differed by producer for all minerals (P &amp;lt; 0.001). Mean α-tocopherol and β-carotene content was 610.6 μg/100 g beef and 32.2 μg/100 g, respectively. The amount of these antioxidants also varied between producers (P &amp;lt; 0.0001), but tended to be greater in beef finished solely on fresh forages. This survey indicates that commercially available GFB can vary in nutritional composition due to the diverse practices used to grass-finish cattle.

PSII-39 Effects of electrostatic spray and natural antioxidants on sensory quality and color of grass- finished beef strip steaks

Abstract This study was aimed to determine the effects of electrostatic spray and natural antioxidants on sensory quality, color, and metmyoglobin reductase activity in grass-finished beef strip steaks. Eighteen certified grass-finished beef loins from nine animals were purchased from a certified grass-fed beef purveyor. Each loin was cut into eight 2.5-cm thick steaks without the gluteus medius muscle. A factorial arrangement of four treatments including a negative control (no spraying; NEG) and 1000-ppm of electrostatic spray of cherry extract rich in ascorbic acid (ES-ACE), electrostatic spray of rosemary and green tea extract rich in polyphenols (ES-RGT), and pressurized spray of ACE (PS-ACE) at 2 retail time points (0 and 5 d) was randomized within an animal. Instrumental color (CIE L*, a*, b*) and reflectance spectra (400 to 700 nm) were measured d-5 steaks. Five loins were randomly selected for metmyoglobin reductase activity and the other four loins were used for sensory evaluation. On d 0, ES_ACE steaks were slightly darker than ES_RGT and NEG steaks (P &amp;lt; 0.022); however, these differences disappeared on d 5 (P ≥ 0.138). On d 0, redness of ES_RGT and NEG steaks were greater than that of ES_ACE and PS_ACE steaks (P &amp;lt; 0.002); however, both ES_ACE and PS_ ACE steaks had more redness than ES_RGT and NEG steaks (P &amp;lt; 0.002). Similar phenomenon was found for color saturation. Both ES_ACE and PS_ACE steaks had less metmyoglobin and more oxymyoglobin than ES_RGT and NEG steaks on d 5 (P ≤ 0.021). All steaks had more sourness, bloody, and oxidized off-flavors on d 5 than d 0 (P ≤ 0.017). Electrostatic and pressurized spray provided similar protection for color stability and sensory quality; however, the natural antioxidant rich in ascorbic acid was more effective than polyphenol-rich natural extract.

143 Impacts of soil carbon sequestration on life cycle greenhouse gas emissions in midwestern USA beef finishing systems

Abstract Using life cycle analysis (LCA), several studies have concluded that grass-finished beef systems have greater GHG intensities than feedlot-finished (FL) beef systems. These studies evaluated only one grazing management system– continuous grazing – and assumed steady-state soil carbon (C), to model the grass-finishing environmental impact. However, by managing for more optimal forage growth and recovery, adaptive multi-paddock (AMP) grazing can improve animal and forage productivity, potentially sequestering more soil organic carbon (SOC) than continuous grazing. To examine impacts of AMP grazing and related SOC sequestration on net GHG emissions, a comparative LCA was performed of two different beef finishing systems in the Upper Midwest, USA: AMP grazing and FL. We used on-farm data collected from the Michigan State University Lake City AgBioResearch Center for AMP grazing. Impact scope included GHG emissions from enteric methane, feed production and mineral supplement manufacture, manure, and on-farm energy use and transportation, as well as the potential C sink arising from SOC sequestration. Across-farm SOC data showed a 4-year C sequestration rate of 3.59 Mg C ha−1 yr−1 in AMP grazed pastures. After including SOC in the GHG footprint estimates, finishing emissions from the AMP system were reduced from 9.62 to −6.65 kg CO2-e kg carcass weight (CW)−1, whereas FL emissions increased slightly from 6.09 to 6.12 kg CO2-e kg CW−1 due to soil erosion. This indicates that AMP grazing has the potential to offset GHG emissions through soil C sequestration, and therefore the finishing phase could be a net C sink. However, FL production required only half as much land as AMP grazing. This research suggests that AMP grazing can contribute to climate change mitigation through SOC sequestration and challenges existing conclusions that only feedlot-intensification reduces the overall beef GHG footprint through greater productivity.

Effects of Finishing Diet and Packaging on Longissimus Dorsi Color

ObjectivesMeat color is extremely influential in purchasing decisions as consumers associate a bright-red color with freshness. The type of finishing diet can influence beef color. Previous studies have shown that grass-finished cattle have darker muscle color than grain-finished cattle. With the use of modified atmospheric packaging (MAP), beef purveyors are able to vary the gas compositions within a package and enhance beef color. However, limited studies have determined the effects of modified atmospheric packaging on grass-finished beef color. The objective of this study was to determine how finishing diet and packaging type affects the color of the longissimus dorsi (LD) muscle.Materials and MethodsDuring the stocker period, all of the cattle were on a forage diet. Cattle were then randomly assigned to either a conventional grain-based diet or an alfalfa pasture diet for finishing. Both conventionally and pasture-finished cattle were fed for 91 d. Cattle were slaughtered on the same day at a commercial beef processing facility under normal conditions and chilled for approximately 30 h. After grading, one strip loin from each carcass was collected and transported to Oklahoma State University. At 11 d postmortem, one steak (n = 60) from each strip loin was vacuum packaged and randomly assigned to display. Those steaks were then randomly assigned to PVC, HiOx-MAP (80% oxygen and 20% carbon dioxide), or CO-MAP (0.4% carbon monoxide, 69.5% nitrogen, and 30% carbon dioxide) packaging and were displayed under retail conditions for 5 d. Muscle darkening (MD), muscle color (MC), and surface discoloration (SD) were all analyzed by a trained panel (n = 6). MD was evaluated only on d 0 and MC and SD were scored once every 24 h for 0, 1, 2, 3, and 4 d. Lipid oxidation was measured by thiobarbituric acid reactive substances (TBARS) assay on d 4. Data were analyzed using the Mixed Procedure of SAS.ResultsThere was a significant display day by finishing diet by packaging interaction (P &lt; 0.05) for muscle color and surface discoloration. There was also a significant finishing diet by packaging interaction (P &lt; 0.05) for muscle darkening. Steaks packaged in HiOx-MAP remained the most stable in color and the brightest cherry-red colored throughout display time (P &lt; 0.05) compared with other packaging types. PVC was the most discolored (P &lt; 0.05) on d 3 and 4 when compared to HiOx-MAP and CO-MAP with the grain-finished PVC packaged steaks showing the most discoloration on d 4. Pasture-finished steaks packaged in CO-MAP displayed the darkest colored muscle (P &lt; 0.05) on d 0. Steaks packaged in PVC had a higher amount of lipid oxidation (P &lt; 0.05) compared with other packaging types.ConclusionThese results indicate that HiOx-MAP more effectively maintains the desired beef color of bright cherry-red for pasture-finished beef. The results also indicate that the use of appropriate packaging type can minimize the losses due to discoloration of steaks from either grain or grass-finished beef.

Effects of Electrostatic Spray and Natural Antioxidants on Chemical Quality of Grass-Finished Beef Strips Steaks

ObjectivesThis study was aimed to determine how electrostatic spray of natural antioxidants impacts chemical quality of grass-finished beef strip steaks.Materials and MethodsTwenty certified grass-finished beef loins from ten animals were purchased from a certified grass-fed beef purveyor. Two loins of the same animals were cut into sixteen 2.5-cm thick steaks (eight steaks per loin) without the gluteus medius muscle. A factorial arrangement of 4 treatments, including a negative control (no spraying; NEG) and 1000-ppm of electrostatic spray of cherry extract rich in ascorbic acid (ES-ACE), electrostatic spray of rosemary and green tea extract rich in polyphenols (ES-RGT), and pressurized spray of ACE (PS-ACE), and 2 retail time points (0 and 5 d) was randomized within an animal, resulting in two steaks receiving a treatment × day combination within an animal. Five loins were randomly selected for chemical analyses (n = 10 per treatment × day combination). Meat antioxidants were extracted in methanol. The extracted antioxidants were reacted with ABTS+ radical cation (2,2′-azino-bis(3-ethylbenzthiazoline)-6-sulphonic acid diammonium salt) solution diluted to an absorbance of 0.85 to measure Trolox Equivalent Antioxidant Capacity (TEAC) at 734 nm. The extract was also reacted with Folin-Ciocalteu (FC) reagent to measure total phenolic compounds at 765 nm. Thiobarbituric acid reactive substances (TBARS) were extracted in 10% trichloroacetic acid and reacted with thiobarbituric acid and the resulted pigment was measured at 532 nm. Data were analyzed by the GLIMMIX procedure of SAS v9.4 and actual probability was reported.ResultsOn d 0, NEG steaks had less FC values than all treatment steaks (P &lt; 0.001), of which the ES_ACE steaks had 14 and 100% more than PS_ACE and ES_RGT steaks, respectively (P ≤ 0.005). Only ES_ACE steaks had greater FC value than NEG steaks on d 5 (P &lt; 0.001). As a result, TEAC value of ES_ACE steaks was 17 and 75% more than that of PS_ACE and ES_RGT steaks (P ≤ 0.005) and remained greater than that of NEG steaks on d 5 (P = 0.064). Greater antioxidant capacity in ES_ACE and PS_ACE steaks decreased lipid oxidation by 56% (0.9 µg MDA/kg less in ES_ACE and PS_ACE on d 5) as compared with NEG steaks in ES_ACE steaks in contrast to the other treatments (P &lt; 0.001).ConclusionElectrostatic spray of cherry extract rich in ascorbic acid was the most effective antioxidant application to prevent lipid oxidation in grass-finished beef strips steaks.

Comparison of Fatty Acid Content between New Zealand Grass-Fed and American Grain-Fed Beef Strip Loins Varying in Marbling Level

ObjectivesMarbling impacts eating quality and consumer preference of beef as it intensifies flavor, and improves tenderness and juiciness. Triglycerides are the predominate lipid in beef and are considered neutral fatty acids, whereas polar fatty acids are found in the phospholipid portion of beef. Diet of cattle during the finishing period can impact type and saturation of fatty acids in meat.The objective of this research was to evaluate differences in neutral and polar lipid fatty acid content from grass-fed and grain-fed beef of varying quality grades sourced from New Zealand and the United States, respectively.Materials and MethodsBeef strip loins (n = 200) representing two fed cattle types (n = 100/finishing type: grass-finished and grain-finished) and five different USDA quality grades (n = 20 per quality grade: USDA Standard, Select, Low Choice, “Top” Choice: High and Average Choice, and Prime) were acquired from beef processing facilities in New Zealand (grass-fed) and Nebraska (grain-fed). A face steak was cut from the anterior end of each strip loin for fatty acid analysis. Face steaks (n = 200) were frozen and stored at the Gordon W. Davis Meat Science Laboratory until further fabrication. Samples were thawed for 12 to 24 h, trimmed of subcutaneous fat and connective tissue and ground. The ground sample was frozen in liquid nitrogen and homogenized for fatty acid analysis. Lipids were extracted, fractionated into neutral lipid (NL) and polar lipid (PL), derivatized to fatty acid methyl esters and determined by gas chromatography.Statistical analyses were conducted using the procedures of SAS (Version 9.3; SAS Inst. Inc., Cary, NC). Treatment comparisons were tested for significance using PROC GLIMMIX with α = 0.05.ResultsInteractions of cattle diet × marbling level affected the overall concentrations (mg/g) of NL saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) (P &lt; 0.05). Saturated fatty acid and MUFA NL concentration decreased as marbling level decreased, as grain-fed Prime was higher (P &lt; 0.05) than all other treatments. Grain-finished and grass-finished Standard had the lowest (P &lt; 0.05) SFA and MUFA NL concentration compared to all other treatments. Concentration of PUFA NL was higher (P &lt; 0.05) for grain-finished Prime than grain-finished Top Choice and grass-finished Prime. No difference was found between grain-finished Low Choice and Select and grass-finished Top Choice NL concentration (P &gt; 0.05), however all were higher (P &lt; 0.05) than grass-finished and grain-finished Standard and grass-finished Select. A cattle diet × marbling level interaction affected the overall PL concentrations of SFA and MUFA (P &lt; 0.05), but not PUFA (P &gt; 0.05). Generally, polar fatty acid content increased as marbling increased for SFA and MUFA. Grain-finished PUFA PL concentration was higher (P &lt; 0.05) than grass-finished samples. Additionally, PUFA PL concentration increased as quality grade decreased (P &lt; 0.05).ConclusionIn conclusion, polar and neutral fatty acid content increased with increasing quality grades except for PL polyunsaturated fatty acids. Additionally, grain-finished beef steaks generally contained a higher SFA and MUFA NL concentration than grass-finished beef steaks for all quality grades except Low Choice and Top Choice.

A Nutritional Survey of Commercially Available Grass-Finished Beef

Consumer interest in the source of their food, its environmental footprint, and the impact of diet on health has supported the growth of the grass-finished beef (GFB) industry. Studies have concluded that GFB has distinct nutritional differences from conventionally-finished beef. As the GFB industry continues to expand, it is vital to continue to explore the nutritional complexities and variation in the product. To achieve this, a survey of grass-finishing production systems throughout the USA was conducted, and beef finished on the participating farms was analyzed for its nutritional composition, including fatty acid (FA), mineral and fat-soluble vitamin contents. Samples were analyzed from 12 producers and annual production capacity of farms ranged from 25 to 5,000 cattle, with a mean age of cattle at harvest of 26.8 ± 2.30 mo. An array of finishing diets included grazing exclusively in perennial pasture, incorporating annual forage crops, and feeding a variety of harvested forages with supplementation of non-starch feed byproducts. Beef muscle tissue FA content was analyzed by gas chromatography-mass spectrometry (GC–MS). The mean ratio of omega-6 (n-6) to omega-3 (n-3) FA in samples varied significantly by producer, ranging from 1.80 to 28.3 (P &lt; 0.0001), with an overall sample set median of 4.10. A selection of minerals including iron, magnesium, and potassium were analyzed by ICP emission spectroscopy and mineral content significantly differed by producer for all minerals (P &lt; 0.001). Mean α-tocopherol and β-carotene content was 610.6 µg/100 g beef and 32.2 µg/100 g, respectively. The amount of these antioxidants also varied between producers (P &lt; 0.0001), but tended to be greater in beef finished solely on fresh forages. This survey indicates that commercially available GFB can vary in nutritional composition due to the diverse practices used to grass-finish cattle.

Effects of Finishing Diet and Packaging on Longissimus Dorsi Color

ObjectivesMeat color is extremely influential in purchasing decisions as consumers associate a bright-red color with freshness. The type of finishing diet can influence beef color. Previous studies have shown that grass-finished cattle have darker muscle color than grain-finished cattle. With the use of modified atmospheric packaging (MAP), beef purveyors are able to vary the gas compositions within a package and enhance beef color. However, limited studies have determined the effects of modified atmospheric packaging on grass-finished beef color. The objective of this study was to determine how finishing diet and packaging type affects the color of the longissimus dorsi (LD) muscle.Materials and MethodsDuring the stocker period, all of the cattle were on a forage diet. Cattle were then randomly assigned to either a conventional grain-based diet or an alfalfa pasture diet for finishing. Both conventionally and pasture-finished cattle were fed for 91 d. Cattle were slaughtered on the same day at a commercial beef processing facility under normal conditions and chilled for approximately 30 h. After grading, one strip loin from each carcass was collected and transported to Oklahoma State University. At 11 d postmortem, one steak (n = 60) from each strip loin was vacuum packaged and randomly assigned to display. Those steaks were then randomly assigned to PVC, HiOx-MAP (80% oxygen and 20% carbon dioxide), or CO-MAP (0.4% carbon monoxide, 69.5% nitrogen, and 30% carbon dioxide) packaging and were displayed under retail conditions for 5 d. Muscle darkening (MD), muscle color (MC), and surface discoloration (SD) were all analyzed by a trained panel (n = 6). MD was evaluated only on d 0 and MC and SD were scored once every 24 h for 0, 1, 2, 3, and 4 d. Lipid oxidation was measured by thiobarbituric acid reactive substances (TBARS) assay on d 4. Data were analyzed using the Mixed Procedure of SAS.ResultsThere was a significant display day by finishing diet by packaging interaction (P < 0.05) for muscle color and surface discoloration. There was also a significant finishing diet by packaging interaction (P < 0.05) for muscle darkening. Steaks packaged in HiOx-MAP remained the most stable in color and the brightest cherry-red colored throughout display time (P < 0.05) compared with other packaging types. PVC was the most discolored (P < 0.05) on d 3 and 4 when compared to HiOx-MAP and CO-MAP with the grain-finished PVC packaged steaks showing the most discoloration on d 4. Pasture-finished steaks packaged in CO-MAP displayed the darkest colored muscle (P < 0.05) on d 0. Steaks packaged in PVC had a higher amount of lipid oxidation (P < 0.05) compared with other packaging types.ConclusionThese results indicate that HiOx-MAP more effectively maintains the desired beef color of bright cherry-red for pasture-finished beef. The results also indicate that the use of appropriate packaging type can minimize the losses due to discoloration of steaks from either grain or grass-finished beef.

Effects of Electrostatic Spray and Natural Antioxidants on Chemical Quality of Grass-Finished Beef Strips Steaks

ObjectivesThis study was aimed to determine how electrostatic spray of natural antioxidants impacts chemical quality of grass-finished beef strip steaks.Materials and MethodsTwenty certified grass-finished beef loins from ten animals were purchased from a certified grass-fed beef purveyor. Two loins of the same animals were cut into sixteen 2.5-cm thick steaks (eight steaks per loin) without the gluteus medius muscle. A factorial arrangement of 4 treatments, including a negative control (no spraying; NEG) and 1000-ppm of electrostatic spray of cherry extract rich in ascorbic acid (ES-ACE), electrostatic spray of rosemary and green tea extract rich in polyphenols (ES-RGT), and pressurized spray of ACE (PS-ACE), and 2 retail time points (0 and 5 d) was randomized within an animal, resulting in two steaks receiving a treatment × day combination within an animal. Five loins were randomly selected for chemical analyses (n = 10 per treatment × day combination). Meat antioxidants were extracted in methanol. The extracted antioxidants were reacted with ABTS+ radical cation (2,2′-azino-bis(3-ethylbenzthiazoline)-6-sulphonic acid diammonium salt) solution diluted to an absorbance of 0.85 to measure Trolox Equivalent Antioxidant Capacity (TEAC) at 734 nm. The extract was also reacted with Folin-Ciocalteu (FC) reagent to measure total phenolic compounds at 765 nm. Thiobarbituric acid reactive substances (TBARS) were extracted in 10% trichloroacetic acid and reacted with thiobarbituric acid and the resulted pigment was measured at 532 nm. Data were analyzed by the GLIMMIX procedure of SAS v9.4 and actual probability was reported.ResultsOn d 0, NEG steaks had less FC values than all treatment steaks (P < 0.001), of which the ES_ACE steaks had 14 and 100% more than PS_ACE and ES_RGT steaks, respectively (P ≤ 0.005). Only ES_ACE steaks had greater FC value than NEG steaks on d 5 (P < 0.001). As a result, TEAC value of ES_ACE steaks was 17 and 75% more than that of PS_ACE and ES_RGT steaks (P ≤ 0.005) and remained greater than that of NEG steaks on d 5 (P = 0.064). Greater antioxidant capacity in ES_ACE and PS_ACE steaks decreased lipid oxidation by 56% (0.9 µg MDA/kg less in ES_ACE and PS_ACE on d 5) as compared with NEG steaks in ES_ACE steaks in contrast to the other treatments (P < 0.001).ConclusionElectrostatic spray of cherry extract rich in ascorbic acid was the most effective antioxidant application to prevent lipid oxidation in grass-finished beef strips steaks.

Comparison of Fatty Acid Content between New Zealand Grass-Fed and American Grain-Fed Beef Strip Loins Varying in Marbling Level

ObjectivesMarbling impacts eating quality and consumer preference of beef as it intensifies flavor, and improves tenderness and juiciness. Triglycerides are the predominate lipid in beef and are considered neutral fatty acids, whereas polar fatty acids are found in the phospholipid portion of beef. Diet of cattle during the finishing period can impact type and saturation of fatty acids in meat.The objective of this research was to evaluate differences in neutral and polar lipid fatty acid content from grass-fed and grain-fed beef of varying quality grades sourced from New Zealand and the United States, respectively.Materials and MethodsBeef strip loins (n = 200) representing two fed cattle types (n = 100/finishing type: grass-finished and grain-finished) and five different USDA quality grades (n = 20 per quality grade: USDA Standard, Select, Low Choice, “Top” Choice: High and Average Choice, and Prime) were acquired from beef processing facilities in New Zealand (grass-fed) and Nebraska (grain-fed). A face steak was cut from the anterior end of each strip loin for fatty acid analysis. Face steaks (n = 200) were frozen and stored at the Gordon W. Davis Meat Science Laboratory until further fabrication. Samples were thawed for 12 to 24 h, trimmed of subcutaneous fat and connective tissue and ground. The ground sample was frozen in liquid nitrogen and homogenized for fatty acid analysis. Lipids were extracted, fractionated into neutral lipid (NL) and polar lipid (PL), derivatized to fatty acid methyl esters and determined by gas chromatography.Statistical analyses were conducted using the procedures of SAS (Version 9.3; SAS Inst. Inc., Cary, NC). Treatment comparisons were tested for significance using PROC GLIMMIX with α = 0.05.ResultsInteractions of cattle diet × marbling level affected the overall concentrations (mg/g) of NL saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) (P < 0.05). Saturated fatty acid and MUFA NL concentration decreased as marbling level decreased, as grain-fed Prime was higher (P < 0.05) than all other treatments. Grain-finished and grass-finished Standard had the lowest (P < 0.05) SFA and MUFA NL concentration compared to all other treatments. Concentration of PUFA NL was higher (P < 0.05) for grain-finished Prime than grain-finished Top Choice and grass-finished Prime. No difference was found between grain-finished Low Choice and Select and grass-finished Top Choice NL concentration (P > 0.05), however all were higher (P < 0.05) than grass-finished and grain-finished Standard and grass-finished Select. A cattle diet × marbling level interaction affected the overall PL concentrations of SFA and MUFA (P < 0.05), but not PUFA (P > 0.05). Generally, polar fatty acid content increased as marbling increased for SFA and MUFA. Grain-finished PUFA PL concentration was higher (P < 0.05) than grass-finished samples. Additionally, PUFA PL concentration increased as quality grade decreased (P < 0.05).ConclusionIn conclusion, polar and neutral fatty acid content increased with increasing quality grades except for PL polyunsaturated fatty acids. Additionally, grain-finished beef steaks generally contained a higher SFA and MUFA NL concentration than grass-finished beef steaks for all quality grades except Low Choice and Top Choice.

Retail stability of three beef muscles from grass-, legume-, and feedlot-finished cattle.

This study aimed to determine the influence of finishing diet on beef appearance and lipid oxidation of three beef muscles. A total of 18 Angus steers were selected from three diet treatments: grass-finished (USUGrass), legume-finished (USUBFT), and grain-finished (USUGrain). After processing, longissimus thoracis (LT), triceps brachii (TB), and gluteus medius (GM) steaks were evaluated over a 7-d display period. A muscle × diet interaction was observed for instrumental lightness (L*) and redness (a*) (P ≤ 0.001). Within each combination, USUGrass was considered darker with lower (P < 0.05) L* compared with USUGrain. For USUBFT, L* was similar to USUGrain for the TB and LT, while the L* of USUBFT and USUGrain GM differed (P < 0.05). In terms of redness, LT a* values were elevated (P < 0.05) in USUGrass compared with USUBFT and USUGrain. For GM steaks, a* of USUBFT and USUGrass were each greater (P < 0.05) than USUGrain. Surface a* of TB steaks were greatest (P < 0.05) for USUGrass followed by USUBFT, and with USUGrain, being lowest (P < 0.05). An overall increase in L* was observed throughout display dependent on diet (P = 0.013). During display, USUGrain steaks had the greatest (P < 0.05) L* followed by USUBFT and USUGrass. Additionally, a day × muscle interaction was observed for a* (P = 0.009). Initially, TB steaks had the greatest (P < 0.05) a* values. However, at day 3, a* values were similar (P > 0.05) among muscles. Visual color scores were in agreement with loss of redness (a*) during display, dependent on diet and muscle type (P < 0.001). Similarly, a day × diet × muscle interaction was observed for visual discoloration (P < 0.001). Day and diet interacted to influence thiobarbituric acid reactive substances (TBARS) (P < 0.001). Initial values did not differ (P > 0.05) between USUGrain and USUBFT; however, USUGrass had lower initial (P < 0.05) TBARS than both USUGrain and USUBFT. At days 3 and 7, TBARS were greatest (P < 0.05) in USUGrain steaks, followed by USUBFT, which was greater (P < 0.05) than USUGrass. A diet × muscle interaction was observed for 10 volatile compounds originating from lipid degradation (P ≤ 0.013). These compounds were less (P < 0.05) abundant in USUGrass compared to TB or GM of USUGrain. This study determined grass-finished beef to have a darker more red color and less lipid oxidation in multiple muscles. Possible mechanisms for this may include an increase in endogenous antioxidants in grass-finished beef.