This study investigates the impact of organic grass-fed (GRA) versus conventional (CON) cattle-feeding systems on human postprandial metabolism. A randomized, double-blind crossover study was used to compare GRA and CON beef consumption in healthy participants (n = 10). Blood samples from participants were collected at fasting and postprandially after consuming a 6-ounce steak from each condition. Triglycerides (TG), cholesterol (CHOL), high-density lipoprotein (HDL), glucose (GLU), and insulin (INS), eight inflammation markers, and 16 amino acids were measured. Analysis utilized net area under the curve (AUC), linear models, and repeated measures ANOVA. Postprandial lipid and glucose responses did not differ. INS AUC was significantly greater in CON than GRA (p = .006). Inflammation response did not differ. Leucine AUC was greater in CON than GRA (p < .05). These results suggest that when consuming CON and GRA beef, lipid and inflammatory responses are similar, but amino acid differences may influence insulin response.

Though the curing of meat has been practiced for centuries, as a means of preserving meat and fish for times of scarcity, it was only in the 20th century that the chemistry surrounding nitrite's multifunctional role in this process began to be elucidated. Nitrite is a very reactive anion, and strict regulations exist limiting the quantity added to meat products. Its counterpart, nitrate, is used as a source of nitrite after bacterial breakdown or pre-conversion, but its usage is permitted only to very specific meat products. This chapter discusses the basic ingredients employed to cure meat products, some regulations pertaining to them, how the cure is distributed/applied to the different categories of cured meat products, and the entry of 'so called' natural nitrite/nitrate-free meat products into the market.

Background/Objectives: Cattle-feeding systems may have health implications for consumers of beef products. Organic grass-fed (GRA) and conventional (CON) cattle-feeding systems may result in beef products with differing metabolite profiles and therefore could impact the postprandial metabolomic response of consumers. This study aims to measure whole beef metabolomics and postprandial metabolomic response of consumers between GRA and CON beef to elucidate potential health implications. Methods: This study followed a randomized double-blind crossover design with healthy male and female subjects (n = 10). Plasma samples were taken at fasting (0) and postprandially for four hours after consumption of a steak from each condition. Untargeted metabolomic analysis of whole beef and human plasma samples used LC/MS. Multivariate and pathway enrichment analysis in MetaboAnalyst was used to investigate metabolite and biochemical pathways that distinguished CON and GRA. Results: Cattle-feeding systems impacted both postprandial and whole beef steak metabolomic profiles. Metabolites that contributed to this variation included carnitine species (Proionylcarnitine), fatty acids, amino acids (L-valine), and Calamendiol. These metabolites have been associated with oxidative stress, inflammation, and cardiovascular health. Functional pathway enrichment analysis revealed numerous amino acid degradation pathways, especially branched-chain amino acids, and fatty acid degradation that changed throughout the postprandial time course. Conclusions: These findings suggest that CON and GRA cattle-feeding systems differentially impact whole beef metabolomics, as well as consumer postprandial metabolic responses and the associated health implications.

Flavor of lamb is a major driving factor in eating satisfaction. Dry aging has been used in beef to alter flavor and tenderness. The objective of the research was to determine what affect dry aging had on flavor attributes and the volatile compounds that influence the perception of flavor. Lambs (n = 10) were fed an alfalfa-based concentrate diet for 60 d prior to harvest. Loins were obtained from both sides of the carcass and randomly assigned to an aging treatment; no age (boned and frozen day 0) or 14 d of dry age in cold storage (4°C, 55%RH). Descriptive flavor profile panel evaluated samples and volatile compounds were analyzed from cooked samples. No differences were detected by descriptive flavor panel between fresh and dry aged loin chops for most flavor attributes. However, aged loins were rated saltier than loins not aged. Additionally, aged loin chops tended to have a greater intensity score for mutton and green attributes. Aldehydes were the greatest proportion of the volatile aroma compound chemical classification recovered and identified from the lamb samples. Dry-aged lamb loins yielded greater thiobis-methane (a sulfurous, fishy aroma) than loins without ageing. As expected, muscle fiber tenderness as evaluated by sensory panel was greater for aged loin chops than no age (12.7 and 10.0, respectively). Aged loin chops tended to be juicier as well. Aging in aerobic conditions for up to 14 d can improve tenderness in lamb without significantly impacting flavor, however, there is a tendency to increase the mutton and green flavors with dry aging.

Targets for finished livestock are often determined by expected fat, either subcutaneous or intramuscular. These targets are used frequently to improve eating quality. Lower intramuscular fat, lack of product uniformity, and insufficient tenderness can negatively impact beef acceptability. This study aimed to investigate the differences in gene expression that alter metabolism and intercellular signaling in the muscle and adipose tissue in beef carcasses at different fat endpoints. In this study, longissimus thoracis muscle samples and adipose tissue were collected at harvest, and RNA was extracted and then sequenced using RNAseq. Differential expression was determined using edgeR, and p-values were adjusted using the Benjamini-Hochberg method. A corrected p-value of 0.005 and log2 (fold change) of >1 were the threshold to identify differential expression. Comparison between intermuscular and subcutaneous fat showed no differences in the genes activated in the two adipose tissue depots, suggesting that subcutaneous fat was an adequate sample. Carcass data allowed the classification of carcasses by USDA quality grades (marbling targets). In comparing muscle from Standard and Choice carcasses, 15 genes were downregulated, and 20 were upregulated. There were 49 downregulated and 113 upregulated genes comparing adipose tissue from Standard and Choice carcasses. These genes are related to the metabolism of fat and energy. This indicates that muscle transcript expression varies less than adipose. In addition, subcutaneous fat can be used to evaluate transcript changes in fat. However, it is unclear whether these fat tissues can be used as surrogates for marbling.

Growth is frequently described as weight gain over time. Researchers have used this information in equations to predict carcass composition and estimate fat deposition. Diet, species, breed, and gender all influence fat deposition. Alterations in diets result in changes in fat deposition as well as the fatty acid profile of meat. Additionally, the amount and composition of the fat can affect lipid stability and flavor development upon cooking. Fat functions not only as a storage of energy and contributor of flavor compounds, but also participates in signaling that affects many aspects of the physiological functions of the animal. Transcription factors that are upregulated in response to excess energy to be stored are an important avenue of research to improve the understanding of fat deposition and thus, the efficiency of production. Additionally, further study of the inflammation associated with increased fat depots may lead to a better understanding of finishing animals, production efficiency, and overall health.

Backfat and carcass fatness is an important quality attribute in meat animals. A substantial economic gain in the livestock industry may result from the discovery of metabolites, which can improve methods for predicting desirable livestock traits before harvest. Complex phenotypes can be identified for genetic selection or precision management using metabolic and genetic biomarkers. An analysis of ovine samples collected before harvest from wethers with different degrees of back fat was conducted using serum samples obtained from 15 sheep (5 from each back fat class), 60 d, 30 d, and just before harvest. This study quantified 55 serum metabolites that play important roles in ovine metabolism by 1H nuclear magnetic resonance (NMR) spectroscopy. An RNAseq dataset was generated from each sheep's muscle and adipose tissue at harvest. A statistical analysis of the data was performed using MetaboAnalyst Version 5.0 software in R. The results of multiple analyses showed that three metabolites, betaine, choline, and dimethylamine, are associated with sheep's fat class at a significance of (P < 0.01). Integration with gene expression datasets is still underway due to the limitations of annotating sheep genes. In addition, these metabolites are novel and have never been shown to modulate fat class in sheep. To elucidate methods of predicting which livestock produce ideal carcasses, further research is needed to investigate how betaine and choline impact fatness in sheep.

Fat deposition is important to carcass value and some palatability characteristics. Carcasses with higher USDA quality grades produce more value for producers and processors in the US system and are more likely to have greater eating satisfaction. Using genomics to identify genes impacting marbling deposition provides insight into muscle biochemistry that may lead to ways to better predict fat deposition, especially marbling and thus quality grade. Hereford steers (16) were managed the same from birth through harvest after 270 days on feed. Samples were obtained for tenderness and transcriptome profiling. As expected, steaks from Choice carcasses had a lower shear force value than steaks from Select carcasses; however, steaks from Standard carcasses were not different from steaks from Choice carcasses. A significant number of differentially expressed (DE) genes was observed in the longissimus lumborum between Choice and Standard carcass RNA pools (1257 genes, p < 0.05), but not many DE genes were observed between Choice and Select RNA pools. Exploratory analysis of global muscle tissue transcriptome from Standard and Choice carcasses provided insight into muscle biochemistry, specifically the upregulation of extracellular matrix development and focal adhesion pathways and the downregulation of RNA processing and metabolism in Choice versus Standard. Additional research is needed to explore the function and timing of gene expression changes.

A 3 yr experiment was conducted to evaluate the influence of diet and feeding location on animal performance, carcass characteristics, whole blood counts, and internal parasite burden of lambs assigned to 1 of 4 treatments: 1) confinement fed 71% alfalfa, 18% barley pellet, 5% molasses, 0.013% Bovatec, 6.1% vitamin/mineral package diet (CALF), 2) confinement fed 60% barley, 26% alfalfa pellet, 4% molasses, 2.5% soybean-hi pro, 0.016% Bovatec, 7.4% vitamin/mineral package diet (CBAR), 3) field fed 71% alfalfa, 18% barley pellet, 5% molasses, 0.013% Bovatec, 6.1% vitamin/mineral package diet (FALF), and 4) field fed 60% barley, 26% alfalfa pellet, 4% molasses, 2.5% soybean-hi pro, 0.016% Bovatec, 7.4% vitamin/mineral package diet (FBAR). A year × location interaction was detected for ending body weight (BW), average daily gain (ADG), and dry matter intake (DMI); therefore results are presented by year. In all years, cost of gain and DMI were greater for CALF and FALF than for CBAR and FBAR feed treatments (p ≤ 0.03). In yr 2 and 3 field treatments had greater ending BW and ADG than confinement treatments. For all years, diet did not affect ending BW or ADG. In yr 1 dressing percent and rib eye area were greater for field finished lambs than confinement finished (p ≤ 0.02) and Warner-Bratzler shear force was greater for CALF and FALF (p = 0.03). In yr 2 lambs in FALF and FBAR treatments had greater leg scores and conformation than CALF and CBAR (p = 0.09). In yr 1, FALF had a greater small intestine total worm count than all other treatments. In yr 1, ending Trichostrongyle type egg counts were greater for FALF (p = 0.05). In yr 2, ending Nematodirus spp. egg counts were greater for FALF and lowest for CBAR (p < 0.01). Abomasum Teladorsagia circumcinta worm burden was greater in CALF than all other treatments (p = 0.07) in yr 2. While field finishing lambs with a grain- or forage-based diet we conclude that it is possible to produce a quality lamb product without adverse effects to animal performance, carcass quality or increasing parasite burdens.

USDA quality and yield grade are primary driving forces for carcass value in the United States. Carcass improvements can be achieved by making selection decisions based on the results of genetic evaluations in the form of expected progeny differences (EPD), real-time ultrasound imaging, and physical evaluation of candidate breeding animals. In an effort to advance their ability to accurately predict the breeding value of potential sires for carcass traits, the American Simmental Association launched the Carcass Merit Program as a means to collect progeny sire group carcass information. All records were extracted from the American Simmental Association database. Progeny data were organized by sire family and progeny performance phenotypes were constructed. Sire genotypes were filtered, and a multi-locus mixed linear model was used to perform an association analysis on the genotype data, while correcting for cryptic relatedness and pedigree structure. Three chromosomes were found to have genome-wide significance and this conservative approach identified putative QTL in those regions. Three hundred ninety-three novel regions were identified across all traits, as well as 290 novel positional candidate genes. Correlations between carcass characteristics and maternal traits were less unfavorable than those previously reported.

The Line 1 and Line 4 Hereford populations have been linebred for decades. Since these populations share origins but have been managed differently, they offer a unique opportunity to understand molecular mechanisms contributing to inbreeding depression. The study attempted to identify areas of the genome impacting inbreeding depression. Inbreeding was estimated using a complete pedigree (FPED), genomic inbreeding (FG), and genomic pedigree inbreeding (FGPED). Average rate of change in inbreeding per year was evaluated. Runs of homozygosity (ROH) analyses were performed in Golden Helix SVS software, and ROH were defined as a minimum length of 2,500 kb, 250 single nucleotide polymorphism (SNP) appearing in 20 samples. Expected phenotypes for five traits were calculated by adjusting each animal’s individual phenotype with published negative impacts of inbreeding depression. Regression association analyses were performed (Golden Helix) on phenotype and genotype data. Markers above 5 x 10–4 genome-wide significance were considered strongly significant. Line 1 FPED, FG, and FGPED average inbreeding was 42.1% (range 0–71%), 14.4% (range 0–46%), and 31.0% (range 0–63%), respectively. Line 4 FPED, FG, and FGPED average inbreeding was 12.6% (range 0–36%), 12.3% (range 0–49%), and 17.7% (range 0–29%), respectively. Average rate of change in inbreeding per year for Line 1 was -0.03% over 83 yr and 0.03% over 55 yr for Line 4. Fifty ROH regions, 93 strongly significant SNP, three strongly significant SNP within ROH, and some significant SNP within 11 previously identified genes were identified for Line 1. Forty-five ROH regions, 35 strongly significant SNP, three strongly significant SNP within ROH, and some significant SNP within 12 previously identified genes were identified for Line 4. Variation in identified regions of the genome of both lines indicate management is impacting results of inbreeding and the expressed inbreeding depression.

Abstract Temperament in cattle, is defined as behavioral changes in response to humans or changes in the environment, and has been associated with reduced feed efficiency, reduced growth rate, and poor feedlot health. The objective of the study was to determine if temperament affected the performance, growth and health of feedlot cattle. One-hundred and thirty-one Angus x Simmental steers from a single ranch were sampled at a commercial feedlot in Chappell, NE. Blood samples for metabolite analysis, exit velocity, and blood lactate concentration for temperament classification were collected in addition to feedlot performance data and carcass quality measurements. The GLM and LSM procedures of SAS (SAS 9.4, 2014) were used to evaluate differences between temperament classifications. Pearson correlations were calculated between temperament and performance variables. Steers were divided into three exit velocity classifications, with fast animals (n = 27) having exit velocity greater than one standard deviation from the mean and slow animals (n = 26) having exit velocities lower than one standard deviation from the mean. Feed intake and behavior was monitored for 42 days with GrowSafe feed bunks and average daily gain, dry matter intake and residual feed intake calculated. There were significant differences between the temperament classifications of fast, medium and slow for both exit velocity and blood lactate (P < 0.0001), indicating there was a difference in responses from the classifications. Exit velocity had no effect on any of the growth parameters measured. There was a significant positive correlation between exit velocity and blood lactate (P < 0.0001). RFI was significantly correlated with exit velocity (P = 0. 051) and blood lactate (P < 0.05). This suggests that animals with higher RFI or less efficient animals had more flighty temperaments as determined by blood lactate and exit velocity.

Interest in beef cattle temperament has increased due to growing consumer awareness of animal welfare and increased concern for handler safety. Temperament measures are based on behavioral responses to a perceived stressor. Subjective chute scoring has been used to give a numeric value to temperament; however, the subjectivity and variability among observers have been questioned. To deal with the perceived subjectivity and variability, other researchers have used exit velocity. Researchers have related faster exit velocities to increased cortisol and plasma lactate. The objectives of this study were to compare temperament between feedlot steers and heifers and to confirm chute side measures of temperament relationship to physiological responses to stress. Body temperature, blood and plasma lactate, serum glucose, salivary and serum cortisol concentrations were measured on Bos taurus commercial crossbred feedlot cattle (n = 197). Fast, medium, and slow classifications were developed from exit velocities. Plasma lactate was significantly different between all exit velocity classes. Exit velocity and physiological measures indicated that heifers were more excitable (faster exit velocities (P = 0.003), higher plasma lactate concentrations (P = 0.03), and cortisol concentrations (P = 0.001)). Simple correlations among these variables indicated body temperature (heifers r = 0.44, P < 0.0001; steers r = 0.45, P < .0001), plasma lactate (heifers r = 0.52, P < 0.0001; steers r = 0.63, P < 0.0001), blood lactate (heifers r = 0.53, P < 0.001; steers r = 0.59, P < 0.001), and glucose (heifers r = 0.54, P < 0.001; steers r = 0.32, P <0.003) were all related to exit velocity. Cortisol measures were not correlated to exit velocity in steers but were in heifers. Linear models constructed and evaluated using the Akaike information criterion indicated that blood lactate in combination with rectal temperature were strong candidates to predict exit velocity. Using the discriminate function analysis, the model correctly categorized fast and slow classifications 69.23% and 61.54%, respectively, indicating that in combination measures of body temperature and blood lactate can potentially increase accuracy of temperament identification or replace exit velocity as a measure of temperament. The plasma lactate and rectal temperature have the potential to become strong objective measures to augment or replace exit velocity.

Beef tenderness is a leading influence in consumer decisions to choose beef. Insufficient marbling and subsequent lower quality grades, lack of a uniform product, reduced or insufficient tenderness can negatively impact beef acceptability. The objective of this study was to investigate differences in gene expression, metabolism and intercellular signaling in the muscle and proximate intermuscular adipose tissue in carcasses of differing quality grades. Previous research evaluated Longissimus lumborum muscle sampled at slaughter and a significant number of differences were observed between Choice and Standard carcass samples (1,258 genes<0.01). In this study, RNA was harvested from Longissimus thoracis muscle and associated adipose tissue at slaughter and individual samples were sequenced using RNAseq. Differential expression was determined using edgeR and P-values were adjusted using the Benjamini-Hochberg method. A corrected P-value of 0.005 and one fold change defined significant differential expression. When comparing muscle from Standard and Choice carcasses, 15 genes were down regulated and 20 were up regulated. The insulin receptor substrate 1 (IRS 1) gene was the only known functionally important gene to be differentially expressed. There were 49 down-regulated genes and 113 up-regulated genes in the comparison between adipose tissue from Standard and Choice carcasses. The function of these genes was primarily metabolism of fat and energy. This potentially demonstrates that intermuscular adipose tissue can play a bigger role in meat quality and tenderness levels than currently known.

The majority of U.S. lambs are born during late winter or early spring, which can create downstream variability in carcass quality if commercial lamb harvest is to be relatively constant throughout the year. Flavor is an important quality determining characteristic of sheep meat and is influenced, in part, by animal age at harvest. However, management practices to mitigate the risk of objectionable flavors in meat from old crop lambs or yearlings are not well known. Yearling (16.8 ± 0.14 mo) Rambouillet wethers were assigned to 1 of 3 treatment groups, which consisted of feeding a 20% ground sorghum-sudangrass hay diet for 40 d (JUN0; n = 10), a 20% ground juniper diet for 40 d (JUN40; n = 10), or a 20% ground hay diet for 20 d followed by a 20% ground juniper diet for 20 d (JUN20; n = 10). Wethers were harvested on day 41 and a whole bone-in loin and a boneless inside leg roast were fabricated from one side each of carcass. After grilling (loin chop) or convection air roasting (leg roast), trained sensory panel evaluation and measurement of aroma volatiles by gas chromatography/mass spectrometry were performed. Treatment diet did not affect (P ≥ 0.17) wether feedlot performance, dressing percentage, or loin eye area. However, wethers fed JUN0 tended (P = 0.06) to have greater back fat depth than wethers fed JUN20 or JUN40. No trained sensory panel trait of loin chop samples was affected (P > 0.10) by treatment. Leg roasts from JUN0 and JUN20 wethers had greater (P = 0.01) lamb identification sensory score than JUN40. Benzaldehyde, 1-heptanol, and 1-octanol concentrations were greater (P < 0.05) and decanal and nonenal concentrations were less (P < 0.05) in loin chops from JUN0 compared with JUN40 wethers. Additionally, the terpenes cedr-8-ene, gamma muurolene, and widdrene tended to be greater (P < 0.07) in loin chops from JUN20 and JUN40 than JUN0 wethers. The 2-pentyl-furan concentrations were greatest (P = 0.03) in leg roasts from JUN40 wethers. Like the loin chops, cedr-8-ene, gamma-muurolene, toluene, and widdrene were greater (P < 0.05) in leg roasts from wethers fed either of the juniper diets compared with JUN0. Yearling wethers can be finished on a feedlot diet containing 20% juniper for up to 40 d prior to harvest with no impact on feedlot performance, carcass characteristics, nor negative impact on sensory attributes or volatile compounds of either grilled loin chops or roasted legs.

he objective was to evaluate effects of a Juniperus spp.-based finishing diet (JUN) on feedlot performance, carcass characteristics, fatty acid composition, and sensory panel traits of yearling Rambouillet wethers. Thirty wethers (16.8 ± 0.14 mo) were assigned to an 80% concentrate treatment: 20% ground oat hay fed 40 d (JUN0); 20% JUN fed 40 d (JUN40); or 20 d of the hay diet followed by 20 d of JUN (JUN20). Lambs were harvested on d 41. In the final 20 d, JUN40 wethers had greater DMI (P = 0.05) than JUN20; no other differences were detected (P ≥ 0.12). Treatment had no effect (P ≥ 0.23) on ADG, dressing percentage, loin eye area, or back fat. No trained sensory panel trait was affected (P > 0.10) by diet in the loin. Leg roasts from lambs finished on JUN0 or JUN20 scored higher (P = 0.01) for lamb identification sensory score than lambs finished on JUN40. Benzaldehyde, 1-heptanol, and 1-octanol were higher (P < 0.05) and decanal and nonenal volatiles were lower (P < 0.05) for loin chops from lambs finished on the JUN0 diet compared to the JUN40 diet. The terpenes cedr-8-ene, gamma muurolene and widdrene volatiles were higher (P < 0.07) in chops from lambs fed JUN40 and JUN20 compared to the hay diet. The 2-ethyl-furan and 2-pentyl-furan volatiles were highest (P < 0.05) in leg roasts from JUN40 wethers. While small differences were detected in volatile aroma compounds, neither animal growth nor sensory panel scores were affected by diet. Lambs can be finished on a feedlot diet containing 20% juniper for up to 40 days prior to slaughter with no impact on sensory of either grilled loin chops or roasted lamb legs.

© The Author(s) 2018. Published by Oxford University Press on behalf of the American Society of Animal Science. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com. Transl. Anim. Sci. 2018.2:S163–S166 doi: 10.1093/tas/txy036