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The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Despite a high volume of market (cull) dairy cows entering the food chain every year, beef from market dairy cows is largely considered insignificant when compared with beef from beef cattle in the market and is widely thought to be usable for ground beef only. Our study aimed to evaluate the effects of feeding dairy market cows on a lactating TMR diet before slaughter on carcass and beef quality traits. Forty-three Holstein market cows were randomly assigned into 2 treatments: fed or direct. Fed cows (n = 22) were dried off and then fed a lactating cow TMR ration for approximately 60 d, whereas direct cows (n = 21) were sent directly to slaughter. Hot carcass weight (HCW) was used to calculate the dressing percentage (DP), together with the animals' BW, recorded when animals left the farm to go to the abattoir. At 24 h postmortem, the rib fat thickness (RFT) and rib eye area (REA) were measured by a certified grader. Afterward, rib samples were collected between the twelfth and tenth ribs from one side of the carcass and divided into 5 rib eye steaks. The first steak was used for intramuscular fat (IMF) content analysis by near-infrared spectroscopy. The other 4 steaks were then aged for 7, 14, 21, or 28 d. Following aging, the steaks available were assessed for tenderness using the Warner-Bratzler shear force protocol. Data were analyzed by mixed linear regression to compare experimental groups for continuous outcomes. The HCW of the fed cows was higher than the direct cows, with mean HCW of 408.3 kg and 326.1 kg, respectively (SE ± 9.0). Average DP in fed cows was 49.1%, compared with 42.5% in direct cows (SE ± 0.69). The average percentage of IMF in fed cows was 8.1% and 5.0% in direct cows (SE ± 0.43). Fed cows had a mean REA of 68.1 cm2, and direct cows had a mean of 57.7 cm2 (SE ± 11.9). No differences were found for RFT. The steaks aged for 14 d resulted in meat with a mean shear force (SF) of 4.19 kg in fed cows, whereas direct cows had a mean SF of 6.28 kg (SE ± 0.29). Feeding market dairy cows for 60 d before slaughter enhanced carcass weight and yield, IMF content, and tenderness. These results indicate that approximately 60 d of feeding can improve the quality of market dairy cow meat and may help improve market cow value. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the antimicrobial efficacy of peroxyacetic acid (PAA) for beef in processing facilities. Inactivation of a wildtype Escherichia coli strain by up to 400 ppm PAA in solutions with different organic loads was determined. The microbial efficacy of PAA was assessed at two commercial beef plants for carcasses and cuts during routine production. The wild type E. coli strain was reduced by >7 log CFU upon exposing to PAA for 15 s at >100 and 200 ppm in low and high organic load solutions, respectively. PAA spray significantly reduced coliforms and E. coli by 1.7–2.0 log units on carcasses artificially inoculated with fecal slurry at one plant, and reduced aerobes and coliforms by 1.7 and 1.0 log units on naturally contaminated carcasses at the other plant. The reduction by PAA spray of aerobes (p < 0.05) on artificially inoculated carcasses was <0.5 log. Significant and consistent reduction of aerobes and coliforms on cuts by PAA was observed for fat surface at both beef plants, but not for lean cut surface. However, fewer cuts sprayed with PAA were positive for E. coli, regardless of cut type, compared with those that were not sprayed. Taken together, PAA can be effective for reducing microbial contamination of beef carcasses and cuts in commercial practice. [ABSTRACT FROM AUTHOR]

Objective: The purposes of this study were to investigate the relationship between carcass unit price per 1 kg (UP) and multiple muscles and intermuscular fat (IF)/subcutaneous fat of beef carcasses using image analysis of cross-section images for Wagyu beef cattle in Japan, and to estimate their genetic parameters. Methods: The carcasses used in this study were 1,807 Japanese Black (Wagyu) cattle (1,216 steers and 591 heifers). An analysis of variance was conducted with UP as the dependent variable and market date, age in months, sex, and image analysis traits (IAT) as fixed effects, and standard partial regression coefficients were calculated for each IAT on UP. Also, the heritability of each IAT that affected UP and genetic correlation among IAT vs carcass grading traits were estimated. Results: Not only IAT related to carcass grading traits, M. trapezius dorsi, M. latissimus dorsi, and IF traits were significant differences in UP (p<0.05). The heritability of IAT associated with UP was estimated at 0.38 to 0.85. The genetic correlations between the area and thickness of M. trapezius dorsi and M. latissimus dorsi vs rib eye area (REA) were estimated to be moderately positive (0.53 to 0.66), while the genetic correlations between the IF area percentage vs carcass weight, REA, and yield score were estimated to be negative (–0.40, –0.56, and –0.34). Conclusion: UP was influenced by various traits, including M. trapezius dorsi, M. latissimus dorsi, and IF traits, as well as image analysis associated with carcass grading traits. Since these IAT associated with UP had hereditary and desirable genetic correlations with carcass grading traits, these traits were also important for genetic improvement. [ABSTRACT FROM AUTHOR]

Dry-aged meat is gaining popularity among food business operators and private consumers. The process is carried out in aerobic conditions by hanging beef carcasses or placing subprimal or primal cuts in a dedicated cabinet for several weeks or even months while controlling the environment through the management of process parameters such as temperature, relative humidity, and airflow. In this review, we present a critical evaluation of the literature to evaluate tools to manage the process to guarantee food safety and identify critical control points, as well as good hygiene and manufacturing practices. In controlled aging conditions, only Listeria monocytogenes and Yersinia enterocolitica can multiply, while a reduction in the number of Salmonella spp. and Escherichia coli O157:H7 is generally reported. Enterobacteriaceae usually decrease on the surface of the meat during maturation; thus, for the purpose of the hygiene evaluation of the production process, a count no higher than that of unmatured meat is expected. Besides, various studies report that the total bacterial count and the spoilage microorganisms significantly increase on the surface of the meat, up to 5-6 Log10 CFU/g in the absence of visible spoilage. Bacteria of the Pseudomonas genus tend to progressively replace other microorganisms during maturation; thus, the total mesophilic or psychrophilic bacterial load is not a good indicator of process hygiene for matured meat. Critical parameters for the control of the process are temperature, relative humidity, and ventilation, which should be monitored during the process. For this reason, equipment designed and certified for dryaging must be used, and the manufacturer must validate the process. Food business operators must apply general good manufacturing practices (GMP) and good hygiene practices (GHP) for meat processing and some GMP and GHP specific for dry-aging. Several research needs were identified, among them the evolution of the populations of L. monocytogenes and Y. enterocolitica and the microbiology of the inner parts of the dry-aged meat. [ABSTRACT FROM AUTHOR]

An overview of how macroeconomic shocks affect beef quality‐grade premiums and discounts in the U.S. fed cattle market is discussed. We review the shock transmission linkages along the beef industry supply chain and determine the economic implications for the finished cattle market. The analysis provides insight into how the fed cattle market responds to macroeconomic shocks. The economic implications of financial risk associated with the behavior of beef carcass quality‐grade premiums and discounts associated with the Great Recession and the COVID pandemic are contrasted and assessed. Data analysis indicates that macroeconomic shocks affect the quality‐grade premium pricing mechanism for finished cattle. The origins of the shock (aggregate demand versus aggregate supply) and government fiscal policy intervention determines how premium levels and premium volatility responds to a macroeconomic shock. Thus, beef carcass quality‐grade premiums are not only subject to industry idiosyncratic risk, such as swings in the seasonal demand for beef, but are also subject to systematic risk associated with business cycle fluctuations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the effectiveness of two different grasses offered to weaned beef breed bulls until slaughter. Three cuts of tall fescue (TF) and meadow fescue (MF) were harvested with as similar chemical composition as possible, pre-wilted and ensiled separately in bales. Forty newly weaned intact bulls of Continental beef breeds were kept indoors and randomized to one of the two silages, complemented with 2.5–3.0 kg grain/day, and followed until slaughter. The two silages were offered simultaneously from the same cut during most of the finishing period. Bulls receiving TF had a higher silage dry matter intake than bulls offered MF (7.69 vs. 7.04 kg-d; P = 0.0026) but had lower carcass weight (370 vs. 380 kg; P = 0.0357). From this limited study it was concluded that replacing traditional MF silage with TF silage might compromise the carcass performance of finishing beef bulls. [ABSTRACT FROM AUTHOR]

Introduction: Mechanical grading can be used to objectively classify beef carcasses. Despite its many benefits, it is scarcely used within the beef industry, often due to infrastructure and equipment costs. As technology progresses, systems become more physically compact, and data storage and processing methods are becoming more advanced. Purpose-built imaging systems can calculate 3-dimensional measurements of beef carcasses, which can be used for objective grading. Methods: This study explored the use of machine learning techniques (random forests and artificial neural networks) and their ability to predict carcass conformation class, fat class and cold carcass weight, using both 3-dimensional measurements (widths, lengths, and volumes) of beef carcasses, extracted using imaging technology, and fixed effects (kill date, breed type and sex). Cold carcass weight was also included as a fixed effect for prediction of conformation and fat classes. Results: Including the dimensional measurements improved prediction accuracies across traits and techniques compared to that of results from models built excluding the 3D measurements. Model validation of random forests resulted in moderate-high accuracies for cold carcass weight (R2 = 0.72), conformation class (71% correctly classified), and fat class (55% correctly classified). Similar accuracies were seen for the validation of the artificial neural networks, which resulted in high accuracies for cold carcass weight (R2 = 0.68) and conformation class (71%), and moderate for fat class (57%). Discussion: This study demonstrates the potential for 3D imaging technology requiring limited infrastructure, along with machine learning techniques, to predict key carcass traits in the beef industry. [ABSTRACT FROM AUTHOR]

Background: Meat contamination occurs in various ways, the most important of which are live animals before slaughter and the slaughter process (de-hiding and evisceration). For this, many substances were used that have an antimicrobial effect and can disinfect the surfaces of the carcass and extend its shelf life. Aim: This research aimed to study the efficiency of using some organic acids (lactic acid and beefxide) to reduce the microbial load (indicator microorganisms) on the surfaces of beef carcasses and some edible organs in the Mosul slaughterhouse. Methods: Two hundred sixty-four swabs (192 carcasses + 72 edible organ samples) were collected over the course of three months from the Mosul slaughterhouse in Nineveh Governorate between September 2023, and December 2023 (132 treated with organic acids and 132 not treated). The petrifilm method was used to detect indicator microorganisms in the samples. Results: Our results showed that the contamination rate in beef carcasses with generic Escherichia coli, coliforms, total coliform counts, and Enterobacteriaceae before treatment was 0.81, 1.22, 1.48, and 1.38 mean log colony forming unit (CFU/cm²), respectively. While the contamination rate in samples treated with organic acids for generic E. coli, coliforms, total coliform counts, and Enterobacteriaceae was -0.1, 0.31, 0.45, and 0.41 mean log CFU/cm2, respectively. Moreover, the level of contamination with indicator microorganisms in edible organs treated with organic acids was lower compared to untreated samples. Even though there was contamination with indicator microorganisms in the liver, heart, and kidney, there was no "significant" difference between them. Whereas there was no significant difference (p > 0.05) between lactic acid and beefxide solution in terms of reducing the rate of contamination of the indicator microorganisms in carcasses and the edible organs samples. Regarding the type of swabs used in the study, the results showed the effectiveness of sponge swabs, as the rate of microbial recovery (indicator microorganisms) was higher (p < 0.01) compared to cotton swabs. Conclusion: The study demonstrated the efficiency of using organic acids (lactic acid and beefxide solution) in reducing the microbial load to a level that does not cause diseases. [ABSTRACT FROM AUTHOR]

The European Commission asks scientific and technical assistance from EFSA to determine the impact of the revision of the Australian monitoring programme on its ability to detect microbiological contamination. Considering that, in 2010, the European Commission determined the current Australian monitoring programme to be equivalent to the EU requirements for microbiological monitoring further to an EFSA scientific assessment, the current and proposed programmes were described and the total number of alerts was compared using a probabilistic modelling approach. In the current programme, only beef and sheep carcasses are monitored using three‐class moving window sampling plans, while in the proposed programme, carcass, bulk meat, primal and offal are monitored using four two‐class sampling plans and Salmonella testing is excluded. The models revealed that the current programme provides a higher number of alerts for APC, while the proposed monitoring programme provides a higher number of alerts for E. coli. For APC and E. coli combined, the mean, 5th and 95th centiles of the uncertainty distribution of the total number of alerts in the current and the proposed monitoring programme are 201 [179, 227] and 172 [149, 194] for beef, and 199 [175, 222] and 2897 [2795, 3008] for sheep, respectively. For Salmonella, there are no alerts for the proposed programme since sampling is excluded while for the current programme, the estimated mean, 5th and 95th centiles of the uncertainty distribution of the number of alerts for a 5‐year period were 143 [126, 144] for heifer/steer, 1.6 [0, 4] for cow/bull and 0 [0, 0] for lamb/sheep. Overall, for APC and E. coli, the estimated total number of alerts was similar (beef) or higher (sheep) for the proposed compared to the current programme. In contrast, Salmonella sampling is excluded from the proposed programme and thus cannot detect the number of current alerts. [ABSTRACT FROM AUTHOR]

This study involved 45 Holstein and 60 Holstein-Charolaise steers, tailored with specific diets according to breed and rearing systems. DNA genotyping was conducted for DGAT1, LEP, SCD1, SREBF1, and TG genes to investigate their impact on carcass conformation traits, beef quality traits, and sensory quality traits. The results showed associations between the genetic variants and the analyzed traits. Specifically, DGAT1 was found to affect drip loss, meat brightness, and color saturation. The TG gene was associated with marbling and meat color. LEP influenced trim fat and pH levels, while SCD1 was linked to metabolic energy live weight gains, and pH levels. SREBF1 was related to fatness. [ABSTRACT FROM AUTHOR]

Beef carcass evaluation is generally the basis for judging the commercial value of the livestock and is consequently one of the most common quality control tests carried out in the meat industry. In the current study, sixty swabs were taken from the outer surface of neck and groin (30 of each) of freshly dressed beef carcasses taken from three local slaughterhouses located in El-Bagour, El-May and El-Shohadaa provinces of Menoufia governorate, Egypt. Swabs were microbiologically examined; the results revealed that groin samples had significantly (P≤0.05) lower contamination levels than that of neck samples. In addition, samples that were collected from El-May’s abattoir revealed the highest bacterial counts, followed by El-Bagour and El-Shohadaa, respectively. Regarding to detection of some pathogenic bacteria in the examined swab samples, S. aureus was the most detected bacteria, followed by Salmonella spp. and E. coli with total incidence 23.3, 18.3 and 15.0, respectively. However, equal number of S. aureus isolates was obtained from neck and groin samples, groin samples showed higher incidence of Salmonella and E. coli than those of neck samples. In addition, staphylococcal enterotoxins were investigated in the contaminated samples. Results revealed that all of the examined samples had enterotoxin type A only. Moreover, E. coli isolates were serotyped into O103:H2, O146:H21 and O117:H4; out of which, three strains were molecularly examined for their Shiga toxin types 1 (stx-1) and 2 (stx-2) genes; where, stx-1 was detected in 66.7% of the examined strains, while stx-2 was not detected in any of the examined isolates. On the other hand, Salmonella strains were serotyped into S. Enteritidis, S. Montevideo, S. Tsevie, S. Typhimurium and S. Shangani were the detected serotypes. Salmonella Typhimurium was detected in higher incidence than the other detected strains. So, regular monitoring of beef carcasses microbiological evaluation, and application of strict hygienic measures are recommended. [ABSTRACT FROM AUTHOR]

Meat contamination occurs in a variety of ways, the most significant of which include live animals prior to slaughter (infected animals), workers and tools used in the slaughter process, and post-slaughter activities to prepare the carcasses (removing the skin and viscera). Raw meat remains the primary source of many diseases caused by microbes that are transmitted to humans, especially those that cause food poisoning, such as Escherichia coli and Salmonella spp., which are considered among the most important health problems facing the world. Therefore, we decided to study the efficiency of using some organic acids (lactic acid and beefxide) to reduce the number of pathogenic Escherichia coli, Salmonella spp., on the surfaces of beef carcasses in the slaughterhouse of Mosul city. Eighty samples (beef carcass sponge swabs) were collected over the course of three months between September 13, 2023, and December 11, 2023, using culture method and polymerase chain reaction. Our findings of pathogenic bacteria including Shiga toxin-producing E. coli, showed the presence of 4 isolates out of 40 carcass samples (4/40: 10%); all were isolated from the sample's prior treatment with organic acids, 3 of which possessed the stx1 gene and one isolate had the stx2 gene. The study also revealed that there were only two isolates of Salmonella spp. (2/40: 5%) in beef carcasses that possessed the invA gene and these are samples that have not been treated with organic acids. This study concludes the effectiveness of lactic acid and beefxide solutions in removing pathogenic bacteria such as Shiga toxin-producing E. coli and Salmonella spp. from beef carcasses. [ABSTRACT FROM AUTHOR]

Copyright of Anbar Journal of Agricultural Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was practical work in a commercial beef cattle enterprise to offer beef producers different options in a total mixed ration (TMR) design. This study was conducted to determine the effects of withdrawing maize silage from TMR during the finishing period on weight gain, carcass yield and beef quality of meat in beef cattle. Fifty-two Holstein Friesian x Belgian Blue crossbred bulls were used in this study for 126 days. These bulls were divided into four feeding methods described as (i) no maize silage in TMR (C1), (ii) maize silage was withdrawn from TMR two months before slaughter (S1), (iii) maize silage was withdrawn from TMR one month before slaughter (S2), and (iv) maize silage was included in TMR until slaughter (C2). Results showed that the fattening performance of experimental bulls was not affected by treatments, except some colour parameters of the muscle. Also, its chemical composition, pH, water holding capacity, drip loss, thawing loss, cooking loss, shear force, thiobarbituric acid reactive substances and radical scavenging activity were not affected by treatments. To conclude, the withdrawal of maize silage from TMR did not affect fattening performance and meat quality, suggesting that there is no need to withdraw maize silage from TMR during the finishing period of fattening in beef cattle. [ABSTRACT FROM AUTHOR]

The rumen microbiota is important for energy and nutrient acquisition in cattle, and therefore its composition may also affect carcass merit and meat quality attributes. In this study, we examined the associations between archaeal and bacterial taxa in the rumen microbiota of beef cattle and 12 different attributes, including hot carcass weight (HCW), dressing percentage, ribeye area (REA), intramuscular fat content, marbling score, fat thickness, yield grade, moisture content, purge loss, and shear force. There were significant correlations between the relative abundance of certain archaeal and bacterial genera and these attributes. Notably, Selenomonas spp. were positively correlated with live weight and HCW, while also being negatively correlated with purge loss. Members of the Christensenellaceae R-7, Moryella, and Prevotella genera exhibited positive and significant correlations with various attributes, such as dressing percentage and intramuscular fat content. Ruminococcaceae UCG-001 was negatively correlated with live weight, HCW, and dressing percentage, while Acidaminococcus and Succinivibrionaceae UCG-001 were negatively correlated with intramuscular fat content, moisture content, and marbling score. Overall, our findings suggest that specific changes in the rumen microbiota could be a valuable tool to improve beef carcass merit and meat quality attributes. Additional research is required to better understand the relationship between the rumen microbiota and these attributes, with the potential to develop microbiome-targeted strategies for enhancing beef production. Key points: • Certain rumen bacteria were associated with carcass merit and meat quality • Moryella was positively correlated with intramuscular fat in beef carcasses • Acidaminococcus spp. was negatively correlated with marbling and intramuscular fat [ABSTRACT FROM AUTHOR]

The relevance of the work was to determine whether the loin eye area of m. longissimus dorsi as a criterion for evaluating the yield of high-value cuts from beef carcasses, is associated with beef characteristics from bulls of the Ukrainian Black-and-White dairy breed. The purpose of the study was to establish correlations between the loin eye area and the slaughter characteristics by the chemical composition, sensory, physical and technological properties of beef. The correlation between the cross-sectional area of the oblong muscle and slaughter indicators, the quality of carcasses, the chemical composition, sensory, physical and technological properties of beef was studied in the bulls of Ukrainian Black-and-White dairy breed (UBWDB) aged from 18 to 24 months. A linear correlation was established between the loin eye area and the slaughter weight (r = 0.404; P > 0.95), the amount of muscle tissue (r = 0.355; P > 0.95), including the highest (r = 0.680; P > 0.999) and the first (r = 0.501; P > 0.99) grades, the content of fat tissue in the carcass (r = 0.477; P > 0.99). The loin eye area correlated inversely (r = -0.607; P > 0.95) with the amount lost in boiling beef, the amount of second-class muscle tissue (r = -0.377; P > 0.95), the development of subcutaneous fat (r = -0.395; P > 0.95), the total ash mass (r = -0.560; P > 0.95), the juiciness of boiled meat (r = -0.522; P > 0.95), taste and aroma of broth (r = -0.587; P > 0.95). There was a tendency for an inverse correlation between the loin eye area and the total fat content of beef (r = -0.119), protein (r = -0.401), dry matter (r = -0.403), acidity (r = -0.458), muscle tissue colour (r = -0.126), conformation (r = -0.127), penetration (r = -0.477), taste (r = -0.214) and aroma (r = -0.363) of boiled meat, tenderness (r = -0.256), residue after chewing (r = -0.442), the thickness of broth (r = -0.207), and to a linear correlation - with the amount of tendons and ligaments (r = 0.331), marbling (r = 0.162), the colour of fat tissue on the carcass (r = 0.276), transparency of the broth (r = 0.180). The practical significance of the data is to obtain knowledge that allows formulating marketing strategies for predicting food quality, quantity of premium and first-grade beef, its technological properties and intended use based on the correlation between the loin eye area of m. longissimus dorsi. [ABSTRACT FROM AUTHOR]

A determination of how the amount of allotted feedlot living space influences both production indicators as well as carcass and meat quality traits obtained from Holstein steers was performed by forming two treatment groups, T14: 65 steers/pen (14 m²/head of space allowances) and T16: 57 steers/pen (16 m²/head of space allowances), with five replications each treatment. The average arrival weight 238 ± 0.74 kg. During the fattening period the cattle was feed twice a day with commercial diets. The steers were slaughtered after a 261-d period. At the moment of the first reimplant a greater average body weight was found in T16 vs T14 (384.25 vs 378.38 kg; P<0.05) and the difference continued until day 261 (612.35 vs 595.54 kg; P<0.05); regarding ADG, hot carcass weight and cold carcass weight the result were: 1.50 vs 1.46 kg (P<0.05), of ADG kg/d; 367.34 vs 360.35 kg (P<0.05) and 366.68 vs 358.78 kg (P<0.05). No difference between treatments were found in dorsal fat, marbling, pH and meat color. The results suggest that an increase from 14 m²/animal to 16 m²/animal improves the production results as well as the hot and cold carcass weight, with no effect on the quality traits of the carcass and beef. [ABSTRACT FROM AUTHOR]

This article discusses the implementation of new grading systems for beef carcasses in Uruguay. The current subjective grading system is being replaced with video image analysis (VIA) to improve accuracy and sorting. The article also mentions research using ultrasound and VIA to predict meat yield. The implementation of more accurate grading systems is important for aligning supply and demand and improving efficiency in the meat industry. The article provides data on carcass characteristics and meat yield in Uruguayan beef, highlighting improvements in marbling scores over time. The study suggests the need for further research and automation of the national evaluation system to enhance carcass grading. Another study focuses on predicting meat yield and quality in Uruguayan beef using different grading systems. The study found that finishing grade and sex of the animal were the most effective factors in predicting meat yield. Video imaging technology and ultrasound techniques were also found to improve accuracy. The study emphasizes the importance of considering meat characteristics such as marbling and fat thickness in predicting meat yield and quality. These methods can help meet market demands and enhance the value of beef products. [Extracted from the article]

This article provides an overview of beef production and carcass evaluation in Brazil. It highlights Brazil's significant role in the global beef market and its record-breaking export revenues. However, Brazil lacks a national carcass grading system, with slaughterhouses using their own metrics to meet market demands. The current standard for carcass classification in Brazil is based on dentition, gender, carcass weight, and subcutaneous/external fat scores. The article also discusses beef cattle production systems, market statistics, and the need for a new Brazilian classification and grading system that incorporates eating quality parameters and technological advancements. [Extracted from the article]

Chilled beef is inevitably contaminated with microorganisms, starting from the very beginning of the slaughter line. A lot of studies have aimed to improve meat safety and extend the shelf life of chilled beef, of which some have focused on improving the decontamination effects using traditional decontamination interventions, and others have investigated newer technologies and methods, that offer greater energy efficiency, lower environmental impacts, and better assurances for the decontamination of beef carcasses and cuts. To inform industry, there is an urgent need to review these interventions, analyze the merits and demerits of each technology, and provide insight into 'best practice' to preserve microbial safety and beef quality. In this review, the strategies and procedures used to inhibit the growth of microorganisms on beef, from slaughter to storage, have been critiqued. Critical aspects, where there is a lack of data, have been highlighted to help guide future research. It is also acknowledge that different intervention programs for microbiological safety have different applications, dependent on the initial microbial load, the type of infrastructures, and different stages of beef processing. [ABSTRACT FROM AUTHOR]

Antecedentes: Entre os fatores não genéticos, a idade de abate é apontada como o fator mais significativo que influencia as propriedades de qualidade da carne e a quantidade de carne bovina. Objetivo: Comparar os efeitos da idade de abate e tipos de músculos nas características de carcaça e atributos de qualidade da carne de touros da raça Holstein Friesian. Métodos: Touros foram abatidos com 18 meses (grupo jovem=YG) e 24 meses (grupo velho=GO) de idade. No final do período de engorda, foram abatidos os 30 touros (YG=14 cabeças; OG=16 cabeças) que foram engordados numa quinta privada. Em seguida, foram avaliadas as características de carcaça e qualidade da carne dos músculos Longissimus dorsi (LD) e Gluteus medius (GM). Resultados: Foi determinado que os touros podem ser abatidos mais tarde porque suas características de carcaça não foram significativamente afetadas ao longo do tempo. Embora as medidas de gordura da carcaça, como escore de marmoreio, espessura de toucinho, o escore de gordura do European Beef Carcass Classification System (SEUROP) aumentou numericamente com o avanço da idade de abate, apenas o aumento da porcentagem de rim, pelve e coração (KPH) o teor de gordura foi estatisticamente significativo (p<0,05). Touros abatidos aos 24 meses de idade tiveram área LD 13,4% maior (p<0,01) do que os do grupo YG. Os touros Holstein Friesian no grupo OG tiveram peso de abate significativamente (p<0,01) maior, bem como pesos de carcaça quente e fria. No entanto, as porcentagens de rendimento de carcaça quente e fria não foram significativamente afetadas pela idade de abate. Os valores de L* (luminosidade), a* (vermelhidão), b* (amarelamento), croma (intensidade da cor) e matiz da carne de touros da raça Holstein Friesian no grupo OG não diferiram significativamente dos touros no YG grupo. No entanto, os valores de L*, a* e croma do músculo GM foram maiores do que os do músculo LD, enquanto o valor de pH24 do músculo GM foi significativamente (p<0,01) maior do que o do músculo LD. Conclusões: Parece mais vantajoso abater touros aos 24 meses de idade para obter carcaças não apenas mais pesadas, mas também com maior pontuação de marmoreio e mais musculosas e, portanto, mais adequadas às exigências atuais do consumidor. [ABSTRACT FROM AUTHOR]

IntroductionMechanical grading can be used to objectively classify beef carcasses. Despite its many benefits, it is scarcely used within the beef industry, often due to infrastructure and equipment costs. As technology progresses, systems become more physically compact, and data storage and processing methods are becoming more advanced. Purpose-built imaging systems can calculate 3-dimensional measurements of beef carcasses, which can be used for objective grading.MethodsThis study explored the use of machine learning techniques (random forests and artificial neural networks) and their ability to predict carcass conformation class, fat class and cold carcass weight, using both 3-dimensional measurements (widths, lengths, and volumes) of beef carcasses, extracted using imaging technology, and fixed effects (kill date, breed type and sex). Cold carcass weight was also included as a fixed effect for prediction of conformation and fat classes. ResultsIncluding the dimensional measurements improved prediction accuracies across traits and techniques compared to that of results from models built excluding the 3D measurements. Model validation of random forests resulted in moderate-high accuracies for cold carcass weight (R2 = 0.72), conformation class (71% correctly classified), and fat class (55% correctly classified). Similar accuracies were seen for the validation of the artificial neural networks, which resulted in high accuracies for cold carcass weight (R2 = 0.68) and conformation class (71%), and moderate for fat class (57%).DiscussionThis study demonstrates the potential for 3D imaging technology requiring limited infrastructure, along with machine learning techniques, to predict key carcass traits in the beef industry.

In order to estimate the Basic Quality Grade of beef carcasses according to bone maturity, marbling and Bos indicus racial predominance, data from 1,417 carcasses processed in four Federal Inspection Type establishments were analyzed. The following variables were recorded: cavitary fat, rib eye area, dorsal fat thickness, hump length and height, marbling, and bone maturity. Using the variables marbling and bone maturity, the Basic Grade of Quality was estimated in accordance with the norm NOM-004-SAGARPA-2018. The hump height was used as a criterion to determine racial predominance, and four groups were generated from this information. Based on the recorded values, descriptive statistics, analysis of variance, comparison of means, and Tukey's test were determined. The hump height in each group was 7.19, 10.54, 14.38, and 20.11 cm (P<0.01), respectively. 82 % of the carcasses were predominantly Bos indicus. The hot carcass weight was 310.05 kg for group 1 vs 326.99 kg for group 4 (P<0.01). The rib eye area was 85.59 cm² for group 1 vs 89.14 cm² for group 2 (P<0.05). Of the total number of carcasses evaluated, 60 were classified as Supreme quality (4.23 %), 655 as Select quality (46.22 %), 621 as Standard quality (43.82 %), and 81 as Commercial quality (5.72 %). The beef carcasses in this study have mainly a Bos indicus breed component, and their Basic Quality Grade corresponded primarily to a greater number of carcasses with grade A bone maturity, but with less marbling. [ABSTRACT FROM AUTHOR]

Escherichia coli O157:H7 is a cause of foodborne disease and global public health issues especially in developing countries like Ethiopia. A cross‐sectional study was done from January 2022 to July 2022 in Awi Zone to assess the occurrence and antibiograms of E. coli O157:H7. Abattoirs and butcher shops were selected purposively, whereas a systematic random and purposive sampling technique was employed to select study units in abattoirs and butcher shops, respectively. A total of 248 swab samples were collected, isolated, and confirmed using bacteriological culture, biochemical tests, and latex agglutination tests. Escherichia coli O1157:H7 antibiogram tests were performed using Kirby–Bauer disk diffusion method. Logistic regression was used to analyze and measure the degree of association between the presumed risk factors and E. coli O157:H7 occurrence. The overall occurrence of E. coli O157:H7 was estimated to be 8.87% and a relative higher (11.29%) occurrence of E. coli O157:H7 was recorded at butcher shops when compared to abattoirs (6.45%). All isolates were susceptible to gentamicin followed by chloramphenicol (81.81%). About 81.81% of the isolates were resistant to ampicillin and 77.23% of isolates developed resistance to two and more than two antibiotics (MDR). In conclusion, E. coli O157:H7 was detected in the study area. Thus, educating abattoir and butcher shop workers, and consumers, on hygienic handling practices and safe consumption of meat could eliminate foodborne infection associated with E. coli O157:H7 occurrence. [ABSTRACT FROM AUTHOR]

Background: Yersinia enterocolitica is a heterogeneous bacterial species that has been divided into six biotypes and more than 70 serotypes. Each year, the European Food Safety Authority classifies yersiniosis caused by Y. enterocolitica as one of the most important zoonotic diseases. The prevalence of Y. enterocolitica in cattle has not been thoroughly analyzed in Poland, and beef and bovine carcasses contaminated with antimicrobial resistant Y. enterocolitica pose a health risk for both, farm workers and consumers. Therefore, the aim of this study was to evaluate the prevalence of Y. enterocolitica in cattle and to determine the antimicrobial susceptibility of the isolated strains. Results: A total of 1020 samples were analyzed, including 660 rectal swabs collected from live cattle and 360 swabs from cold-stored beef carcasses. The results of this study indicate that Y. enterocolitica was isolated from three of the 15 examined cattle herds and the prevalence within these herds ranged from 0% to nearly 32%. Y. enterocolitica was isolated from 14.7% of the examined heifers, 7.4% of calves and 5.5% of adult cows. More than 65% of the strains were isolated from cold enrichment. The strains isolated from live cattle tested positive for the ystB gene, while ail and ystA genes were not found. Most of the isolated strains belonged to bioserotype 1A/NT. The majority of the isolated strains were resistant to ampicillin, cefalexin and amoxicillin with clavulanic acid, however these are expected phenotypes for Y. enterocolitica. Conclusions: The results of this study indicate that Y. enterocolitica is present in cattle herds in Poland. The strains isolated from live cattle were ystB-positive, most of them belonged to bioserotype 1A/NT. The prevalence of Y. enterocolitica strains was generally low in cold-stored beef carcasses. [ABSTRACT FROM AUTHOR]

Background: Beef slaughterhouses must use a carcass decontamination procedure to control pathogens and thus prevent foodborne diseases transmitted by meat. Objectives: This study aimed to characterize beef carcass decontamination procedures at slaughterhouses located in the province of Antioquia (Colombia). All the slaughterhouses were in service, registered, and approved by Invima (Instituto Nacional de Vigilancia de Medicamentos y Alimentos in Spanish) at the time of the study. Methods: This descriptive study collected information from 23 beef slaughterhouses between July 2019 and April 2021 through documentary reviews and visits to slaughterhouses, using forms and questionnaires. Results: The study allowed the characterization of the procedures used to decontaminate beef carcasses, showing that the chemical disinfection of the carcasses is used to control microorganisms in at least 73.9% of the slaughterhouses analyzed. According to secondary sources, it was found that most of the slaughterhouses are small (slaughter volume <50,000 heads per year); 10 of them use citric acid, lactic acid, peracetic acid, and a mixture of organic acids in concentrations between 900 and 1,200 ppm, 1.5 and 1.7%, 180 and 190 ppm, and 900 and 1,200 ppm, respectively, as carcass disinfectants and according to the technical data sheet of the product. During the visits and through the application of the questionnaire, it was found that the 12 slaughterhouses had implemented chemical disinfection which is not scientifically based, using manual devices as an intervention method to control pathogenic microorganisms. It was found that the type of company, slaughter volume, and the lack of financial resources are the determining factors in the selection of decontamination procedures. The validation of the beef carcass decontamination procedures in the different slaughterhouses in the study was demonstrated. Conclusions: Although it was established that at least one decontamination procedure, such as chemical disinfection, is used in the slaughterhouses of study, this option is not supported by scientific or technical evidence. The findings support the need for improvements in the slaughterhouses of the province of Antioquia, including the improvement of surveillance programs to reduce pathogens in the meat chain effectively. [ABSTRACT FROM AUTHOR]

This study examined the safety and productivity data analysis of a beef cattle farm with Japanese black cattle over a 4-year period following the implementation of a Hazard Analysis and Critical Control Point (HACCP) system in 2018. The critical control point was "the selection of shipping cows" and no deviations from critical limits were observed, indicating the beef were safe. In addition, cattle treated for bovine respiratory disease (BRD) less than 6 months after the introduction of cattle decreased, while the average Beef Marbling Standard and quality of meat (i.e., grades A5, B5, A4, and B4) in beef carcass trade standard scores increased. These results suggest that the HACCP system had a positive effect on the health and meat quality of the cattle. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of training-based intervention on process hygiene, food safety knowledge, and behavior of abattoir workers in Ethiopia. A total of 114 eligible participants and 138 swab samples from abattoir facilities were used to collect data. The pre- and post-intervention food safety knowledge and behaviors of participants were assessed using a structured questionnaire and direct observation, respectively. The swab samples were screened for hygiene indicator bacteria such as Escherichia coli, coliform, total coliform, Enterobacteriaceae, and aerobic plate count using petrifilm plates. The findings showed that participants' food safety knowledge about pathogens and its associated illness (p = 0.004) and hygiene practices (p = 0.009) were significantly improved after intervention. The participant's significant food safety behavioral change was observed in handwashing practices (p < 0.05). The participant's behavior towards cleaning of work and meat contact surfaces was significantly improved after intervention (p = 0.000). Interestingly, the contamination level of generic E. coli (p = 0.034) and Enterobacteriaceae (p = 0.046) was significantly decreased in abattoirs after intervention. A significant reduction of generic E. coli contamination on beef carcasses (p = 0.009) and equipment (p = 0.036) was observed. The coliform (p = 0.013) and total coliform (p = 0.015) contamination of beef carcasses was also significantly reduced after intervention. Moreover, the personnel's clothes and hands showed significantly lower Enterobacteriaceae contamination (p = 0.007) post intervention. The food safety training resulted in improvements of the hygiene process, some behaviors, and knowledge of participants. However, the implementation of integrated mitigation strategies is needed to ensure meat safety in abattoirs. [ABSTRACT FROM AUTHOR]

Simple Summary: Nomadic livestock husbandry is one of the key industries in Mongolia, with more than 70 million livestock, it can fully meet the domestic demand for livestock animal meat, and it has great potential for export to the international market. However, research on the hygienic quality of meat and the prevalence of foodborne pathogens is limited, and the efficacy of hygienic interventions applied in some establishments has not progressed. This is the first report on the evaluation of the baseline microbiological status of meat produced in Mongolian routine slaughterhouses with specific consideration of the efficacy of hygienic interventions. The meat industry has received great attention in Mongolia, having over 70 million livestock, and is important to the nation's economy. Systematic microbiological testing of carcasses has not been mandatorily regulated in all abattoir premises, and the efficacy of the introduction of the Good Hygiene Practice and Hazard Analysis Critical Control Points (HACCP) to some plants has not yet been tested microbiologically in Mongolia. Therefore, samples were collected from two establishments: plant A with an HACCP certificate from a third party and plant B without an HACCP certificate. The rates and levels of the total bacterial count (TBC) as overall hygiene indicators, the Enterobacteriaceae count (EBC) as fecal contamination indicators, and the Staphylococcus spp. count (SC) as personal hygiene indicators were determined on different parts of beef carcasses. The contamination rates in most parts were lower in plant A than in plant B (e.g., TBC in the rump and flank: 103–105 and 105–107, in plant A vs. 104–106 and 105–108 in plant B, respectively). Plant A also had a lower EBC and SC (p < 0.001). Furthermore, 2 out of 100 beef carcasses (2%) were positive for enterohemorrhagic Escherichia coli as a foodborne pathogen indicator in plant A. [ABSTRACT FROM AUTHOR]

Simple Summary: Meat quality and human-health-related indexes are important traits in beef cattle breeding. Intramuscular fat content (IMF) is a major meat quality trait that influences aroma, tenderness, and juiciness. Our objective was to integrate comparative transcriptomic and competing endogenous RNA (ceRNA) network analyses to identify candidate messenger RNAs (mRNAs) and regulatory RNAs involved in molecular regulation of longissimus dorsi muscle (LDM) tissue for IMF and fat metabolism of five beef cattle breeds (Angus, Chinese Simmental, Luxi, Nanyang, and Shandong Black). This study identified the primary metabolic-signaling pathways associated with IMF and fat metabolism, including calcium, cGMP-PKG, thyroid hormone, oxytocin signaling, and other metabolic pathways. In addition, genes MCU, CYB5R1, and BAG3 were common among the 10 comparative groups that were involved in most of the terms related to fat storage and metabolic process. Perhaps differences in expression levels of lipid-metabolism-related RNAs demonstrated molecular factors underlying beef cattle breed differences in IMF and fat metabolism. The results of this study could inform marker-assisted selection and identify regulatory molecular mechanisms associated with IMF in beef cattle. Intramuscular fat content (IMF), one of the most important carcass traits in beef cattle, is controlled by complex regulatory factors. At present, molecular mechanisms involved in regulating IMF and fat metabolism in beef cattle are not well understood. Our objective was to integrate comparative transcriptomic and competing endogenous RNA (ceRNA) network analyses to identify candidate messenger RNAs (mRNAs) and regulatory RNAs involved in molecular regulation of longissimus dorsi muscle (LDM) tissue for IMF and fat metabolism of 5 beef cattle breeds (Angus, Chinese Simmental, Luxi, Nanyang, and Shandong Black). In total, 34 circRNAs, 57 lncRNAs, 15 miRNAs, and 374 mRNAs were identified by integrating gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Furthermore, 7 key subnets with 16 circRNAs, 43 lncRNAs, 7 miRNAs, and 237 mRNAs were detected through clustering analyses, whereas GO enrichment analysis of identified RNAs revealed 48, 13, and 28 significantly enriched GO terms related to IMF in biological process, molecular function, and cellular component categories, respectively. The main metabolic-signaling pathways associated with IMF and fat metabolism that were enriched included metabolic, calcium, cGMP-PKG, thyroid hormone, and oxytocin signaling pathways. Moreover, MCU, CYB5R1, and BAG3 genes were common among the 10 comparative groups defined as important candidate marker genes for fat metabolism in beef cattle. Contributions of transcriptome profiles from various beef breeds and a competing endogenous RNA (ceRNA) regulatory network underlying phenotypic differences in IMF provided novel insights into molecular mechanisms associated with meat quality. [ABSTRACT FROM AUTHOR]

Although beef production is one of the most valuable drivers of the global livestock economy, it is considered the main contributor to GHG emissions derived from livestock. This study's objectives were to estimate the GHG emissions (expressed in carbon dioxide equivalents; CO2-eq) from the beef sector in Greece at the national and prefecture levels during the period 2011–2021 and to explore potential mitigation scenarios. The Tier 1 and 2 methodologies were implemented to estimate the GHG emissions. The total estimated emissions increased over the study period. Although both methodologies captured similar trends in the changes in GHG emissions, the Tier 2 estimations revealed lower emissions and fluctuations due to the different and more precise computational approaches. At the prefecture level, fluctuations in emissions were also noted. However, specific regions showed higher increases in emissions. The observed increase in emissions, in terms of either absolute values (Gg CO2-eq) or intensities (Kg CO2-eq/Kg produced beef carcass), is of utmost importance, and further mitigation strategies should be considered. The regression analysis showed a good predictive ability for emissions, using the number of livestock animals as the input. The equations derived from this analysis could be further used as first-approach tools for capturing future emissions at the national level before proceeding with more elaborate approaches. The different scenarios examined in response to the sector's challenges showed moderate changes in GHG emissions. Depending on national priorities, such scenarios could serve as pilot case studies, which may assist stakeholders in improving the sustainability of the sector in the future. [ABSTRACT FROM AUTHOR]

Simple Summary: The persistent demands for better understanding of the relationship between endocrine adaptation, BW, and productive performances from the perspective of both farmers and the market values of the beef carcass underline that further research on this main topic may be of great interest. In intensive beef production systems, the increase in the prices of feed ingredients has led to changes in the feed formulations, and agri-food wastes can be valorised by incorporating them in diet formulations. In this context, the use of olive cake, a by-product of the olive oil industry, in the formulation of animal feed has been linked with positive effects on the quality of final products, but no previous studies have been conducted to evaluate the thyroid and adrenocortical response to a diet supplemented with olive cake in young growing Limousine beef calves. The present study reveals that the inclusion of olive cake at levels of 10% or 15% in grower/finisher beef diet formulations does not have a detrimental effect on maintaining the physiological thyroid and adrenocortical hormones' concentrations. Agro-industrial by-products incorporated into livestock feed formulations can positively impact feed costs and promote a circular bio-economy. Italy produces significant amounts of olive cake (OC), a by-product of olive oil extraction, with the potential for incorporation into bovine diets. However, information on its effects on endocrine responses in growing beef calves is lacking. Forty-eight Limousines randomly allocated to dietary treatment (control or 10%-OC or 15%-OC inclusion) were segregated according to sex and body weight. Serum concentrations of TSH, thyroid hormones, and cortisol were measured on day 0, day 56, and at the end of the trial on day 147. Circulating TSH, total (T3, T4) and free (fT3, fT4) iodothyronines, and cortisol concentrations were all within the normal physiological ranges, with no significant effect imparted by diet. However, the diet × time interaction was significant for T3. The cortisol, T3, T4, and fT4 registered on day 147 were higher than those of day 56, and cortisol was higher in heifers than bulls. Final body weight was positively correlated with TSH and T3 and negatively with cortisol concentration. These findings suggest that the inclusion of OC at levels up to 15% in growing/finishing beef diets had no adverse effects on the calves' thyroid and cortical status. [ABSTRACT FROM AUTHOR]

Simple Summary: The eating experience of beef is strongly influenced by the amount of marbling or intramuscular fat. Beef steers are fed to a desired level of fatness in order to maximize the probability of a positive eating experience. This work aims to study the genes expressed in muscle and adipose tissue as beef steers deposit body fat to better understand the regulation of this important process and to more effectively predict positive eating experiences. This research identified genes that are altered as beef animals deposit fat in both the muscle and adipose tissues and the processes that are being altered, including the metabolism of fat and energy. The work also identified genes related to inflammation and injury in the adipose tissue that warrant additional research to further understand their role in beef animals. 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. [ABSTRACT FROM AUTHOR]

The cattle industry in Indonesia is very important because it can provide an adequate supply of meat for the community. However, the cattle industry in Indonesia still faces various challenges, such as increasing production costs and low productivity. One way to overcome these challenges is to feed cattle with technology. The purpose of this study was to identify the effect of the physical composition of beef carcasses on the selling price of beef fed with technological feed. This study used a qualitative method with a descriptive approach. Data were collected using observation and literature study techniques. The results showed that the physical composition of cattle carcasses affects the selling price of beef. Cattle with heavier carcasses and a higher percentage of meat tend to have a higher selling price. In addition, cattle with a lower percentage of fat also tend to have a higher selling price. These findings suggest that the use of feed technology can improve the physical composition of cattle carcasses and increase the selling value of beef. [ABSTRACT FROM AUTHOR]

Context: Electrical stimulation is often used by meat processors to promote fast muscle pH decline and optimise meat quality. Meat colour can be made more acceptable by this process, but how this relates to the microstructure and light-scattering properties of muscle is still unknown. Aims: To investigate the effect of electrical stimulation of beef carcasses on the meat colour at grading and the role of the muscle fibre microstructure and light scattering in determining colour differences. Methods: Electrical stimulation inputs (electrical stimulation inputs (ES), n = 8; no electrical stimulation inputs (NS), n = 8) were applied to beef carcasses from female cattle of approximately 18–24 months of age. ES comprised electrical immobilisation, bleed rail electric simulation and hide puller rigidity probe, which have all been shown to increase pH fall post-mortem in beef carcasses. pH fall was monitored, the longissimus thoracis was graded at 20–22 h postmortem and measurements were made of colour, muscle-fibre structure and light scattering. Key results: The decline of pH was increased in ES relative to NS, as indicated by lower pH at 2 h postmortem (5.83 vs 6.86 respectively, s.e. = 0.068; P < 0.05) as well as changes in both chromatic colour a* b* and achromatic (no colour) lightness in the muscle. Chromatic changes were evident as higher grader colour scores, increased redness (a*) and yellowness (b*) with higher levels of oxymyoglobin and lower levels of deoxymyoglobin. Achromatic changes were evident as increased lightness (L*) and surface reflectance (%R) at the meat surface, and increased global brightness within the muscle fibres. Conclusions: Increased lightness and brightness in electrically stimulated muscles were likely to be due to formation of contraction nodes and distortion of muscle fibres, which changed the microstructure of muscle in ways that increased its light-scattering properties. Implications: Consideration of the role of light scattering in determining beef colour at grading will advance understanding of how to improve this important quality trait. Beef meat colour can be affected by electrical stimulation (ES) of carcasses, but how this relates to the microstructure and light-scattering properties of muscle is still unknown. The effect of electrical stimulation inputs on beef longissimus thoracis muscles (n = 16) was investigated. ES promoted both chromatic colour a*b* and achromatic (no colour) lightness changes in the muscle. Increased lightness and brightness were likely to be due to formation of contraction nodes and distortion of muscle fibres, which changed the microstructure, increasing the muscle light-scattering properties. [ABSTRACT FROM AUTHOR]

Carcass and beef quality traits are economically important traits and are expressed by multiple genes. The effects of the MC4R c.856C>G and CACNA2D1 c.2027A>G polymorphisms on carcass and meat quality traits are limited. Therefore, this study aimed at evaluating the association of bovine MC4R and CACNA2D1 markers with carcass characteristics and meat quality. A total of 102 cattle including Turkish Grey Steppe, East Anatolian Red, Zavot, and their F1 crossbreds with the Holstein-Friesians were genotyped using the PCR-RFLP method. The phenotypic traits measured were slaughter weight, hot carcass weight, chilled carcass weight, dressing percentage, chilling loss, carcass fatness score, carcass pH24, and marbling score. Statistical analyses were performed using linear mixed models in the entire cattle population and also from a breed-specific aspect. Population genetics and diversity indices were also estimated. Results revealed that the genetic markers in this study are reasonably informative for the studied cattle population and exhibit an intermediate genetic diversity. Concerning the MC4R c.856C>G polymorphism, there was no significant association with any of the traits analyzed, indicating that this MC4R c.856C>G is not a desirable marker for carcass traits and marbling. Here, we report a novel association between the CACNA2D1 c.2027A>G polymorphism and marbling score. The GG genotype was characterized by higher marbling scores (P<0.05). Bovine CACNA2D1 is located on BTA 4, which consists of important QTLs for marbling, and hence, the evaluation of genetic markers within this genomic region may reveal novel genetic associations through meat quality. [ABSTRACT FROM AUTHOR]

To evaluate the effect of carcass hanging method and aging period on beef eating quality young cross-breed bulls were slaughtered in a slaughterhouse in south-eastern Poland. After the slaughter operations were completed, one carcass side was hung by the Achilles tendon and the other by the hip bone. Suspension methods depending on the carcass sides were used in rotation. Consumer samples were prepared from 14 muscles collected from each of the 50 sides. The use of different hanging methods showed their varied impact on tenderness, juiciness, flavour overall liking and eating quality of beef cuts. A positive effect of tenderstretch on eating quality was observed for six of the muscles (longissimus thoracis, spinalis dorsi, longissimus lumborum, vastus lateralis, gluteus profundus and semimembranosus), no effect was observed for seven, and a negative effect of suspending carcass by hip bone was noted for just one muscle. [ABSTRACT FROM AUTHOR]

E. coli O157:H7 is a known Shiga toxin-producing Escherichia coli (STEC), causing foodborne disease globally. Cattle are the main reservoir and consumption of beef and beef products contaminated with E. coli O157:H7 is an important source of STEC infections in humans. To emphasize the cattle-to-human transmission through the consumption of contaminated beef in Bishoftu, Ethiopia, whole-genome sequencing (WGS) was performed on E. coli O157 strains isolated from three sources (cattle, beef, and humans). Forty-four E. coli O157:H7 isolates originating from 23 cattle rectal contents, three cattle hides, five beef carcasses, seven beef cuts at retail shops, and six human stools in Bishoftu between June 2017 and May 2019 were included. This study identified six clusters of closely related E. coli O157:H7 isolates based on core genome multilocus sequence typing (cgMLST) by targeting 2513 loci. A genetic linkage was observed among the isolate genomes from the cattle rectal contents, cattle hides, beef carcasses at slaughterhouses, beef at retail shops, and human stool within a time frame of 20 months. All the strains carried practically the same repertoire of virulence genes except for the stx2 gene, which was present in all but eight of the closely related isolates. All the strains carried the mdfA gene, encoding for the MdfA multi-drug efflux pump. CgMLST analysis revealed genetically linked E. coli O157:H7 isolates circulating in the area, with a potential transmission from cattle to humans through the consumption of contaminated beef and beef products. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the prevalence of pathogenic bacteria on halal beef carcasses and environmental surfaces in two halal beef slaughterhouses in the United States. To evaluate halal beef slaughter operations, 144 beef carcass samples (pre- and post-evisceration), and 24 environmental site samples (slaughter hall floor, brisket saw, and offal's table) were collected in two halal beef slaughterhouses during June to September 2017. All carcass and environmental samples were analyzed for the presence of Salmonella spp., Escherichia coli O157:H7, and shiga toxin-producing E. coli (non-O157 STEC). Results revealed that Salmonella spp. was isolated and confirmed for the presence of invA gene in 5/36 samples (13.8%) and 5/36 samples (13.8%) at pre-evisceration in plants A and B, respectively. Salmonella spp. was isolated in 2/9 samples (5.6%) of plants A and was not detected in any sample at post-evisceration process. E. coli O157:H7 was not detected in any sample collected from plant A and B. E. coli non-O157 was isolated and confirmed for the presence of virulence genes in 4/36 samples (11.1%) and 2/36 samples (5.5%) at post-evisceration in plants A and B, respectively. Salmonella spp. was detected based on the presence of the Salmonella invA gene in the slaughter hall floor (4/4) and the offal's table (2/4) samples using multiplex polymerase chain reaction (mPCR). In plant B, Salmonella spp. was also confirmed in the slaughter hall floor (2/4) and brisket saw (2/4) samples. On the other hand, one isolate of E. coli O157:H7 and one non-O157 STEC were obtained from the slaughter hall floor of plant A. The E. coli O157:H7 isolate was positive for stx1, stx2, eaeA, and EHEC-hly genes. Two isolates of non-O157 STEC (2/4) were detected in the environmental site samples, one from the slaughter hall floor, and one from an offal's table sample of plant B. These data can be used to inform food safety interventions targeting halal meat operations in the southeastern United States. [ABSTRACT FROM AUTHOR]

Mitochondrial DNA copy number (mtDNA CN) is heritable and easily obtained from low-pass sequencing (LPS). This study investigated the genetic correlation of mtDNA CN with growth and carcass traits in a multi-breed and crossbred beef cattle population. Blood, leucocyte, and semen samples were obtained from 2,371 animals and subjected to LPS that resulted in nuclear DNA (nuDNA) and mtDNA sequence reads. Mitochondrial DNA CN was estimated as the ratio of mtDNA to nuDNA coverages. Variant calling was performed from mtDNA, and 11 single nucleotide polymorphisms (SNP) were identified in the population. Samples were classified in taurine haplogroups. Haplogroup and mtDNA type were further classified based on the 11 segregating SNP. Growth and carcass traits were available for between 7,249 and 60,989 individuals. Associations of mtDNA CN, mtDNA haplogroups, mtDNA types, and mtDNA SNP with growth and carcass traits were estimated with univariate animal models, and genetic correlations were estimated with a bivariate animal model based on pedigree. Mitochondrial DNA CN tended (P -value ≤0.08) to be associated with birth weight and weaning weight. There was no association (P -value >0.10) between mtDNA SNP, haplogroups, or types with growth and carcass traits. Genetic correlation estimates of mtDNA CN were −0.30 ± 0.16 with birth weight, −0.31 ± 0.16 with weaning weight, −0.15 ± 0.14 with post-weaning gain, −0.11 ± 0.19 with average daily dry-matter intake, −0.04 ± 0.22 with average daily gain, −0.29 ± 0.13 with mature cow weight, −0.11 ± 0.13 with slaughter weight, −0.14 ± 0.13 with carcass weight, −0.07 ± 0.14 with carcass backfat, 0.14 ± 0.14 with carcass marbling, and −0.06 ± 0.14 with ribeye area. In conclusion, mtDNA CN was negatively correlated with most traits investigated, and the genetic correlation was stronger with growth traits than with carcass traits. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to determine the influence that similar dietary roughage equivalency offered in a single or two-diet system during a 210-d growing-finishing period has on growth performance, the efficiency of dietary net energy (NE) utilization, and carcass traits in beef steers. Beef steers (n = 46; initial shrunk [4%]; body weight [ BW ] = 281 ± 40.4 kg) were fed once daily, and bunks were managed according to a slick bunk management system across all 10 pens. Treatments included the following: 1) A single diet program that was formulated to provide 16% (dry matter [ DM ] basis) dietary roughage equivalency; SD) or 2) multiple diet programs (formulated to provide a dietary roughage equivalency (DM basis) of 25% for 98 d, 16% for 14 d, and 7% for 98 d; MD). Day 1 to 112 was considered the growing period, and day 113 to 210 (the day of harvest) was considered the finishing period, all steers were implanted on day 1 with a 100 mg trenbolone acetate (TBA) and 14 mg estradiol benzoate (EB) implant and implanted with a 200 mg TBA and 28 mg EB implant on day 112. Average daily gain tended (P = 0.06) to be 9.5% greater for SD compared to MD during the growing portion, and average daily gain (ADG) was greater by 11.3% (P = 0.01) for MD compared to SD during the finishing phase of the experiment. Cumulative ADG did not differ (P ≥ 0.86) between treatments (1.61 vs. 1.62 ± 0.046 kg) for SD and MD, respectively. Cumulative dietary NEm and NEg calculated based on performance did not differ (P ≥ 0.96) between treatments. There were no differences (P ≥ 0.18) detected between treatments for hot carcass weight, dressing percent, longissimus muscle area, rib fat, United States Department of Agriculture (USDA) marbling score, kidney, pelvic, heart fat, yield grade, retail yield, empty body fat, or body weight at 28% estimated empty body fat. These data indicate that feedlot producers can feed a single growing-finishing diet to beef steers with minimal effects on overall growth performance or carcass traits. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate potency and timing of trenbolone acetate (TBA) administration on live performance and carcass characteristics of beef × dairy steers. A total of 6,895 beef × dairy steers [initial body weight (BW) = 157 ± 5.2 kg] were allotted into 30 pens, with pen as the experimental unit. Each pen was randomly assigned one of three implant treatments: 1) Revalor-IS (IS) at d 0, IS at d 80, and Revalor-XS (XS) at d 160 (IS/IS/XS); 2) Ralgro at d 0, IS at d 80, and XS at d 160 (Ral/IS/XS); or 3) Encore at d 0 and XS at d 160 (Enc/XS). Steers were blocked by arrival date, each pen was terminally sorted in three ways at 257 ± 22 days on feed and harvested at 329 ± 25 days on feed. For live and carcass outcomes, fixed effect of implant treatment and random effect of block was evaluated. Data are reported on a deads and removals out basis. Removals, morbidity, and mortality were similar (P  ≥ 0.45). Steers administered TBA prior to d 160 were 5.8 kg heavier (P  = 0.03) than Enc/XS steers at d 160. Final BW was not different (P  = 0.78). Early administration of a TBA-containing implant resulted in an increased prevalence of bullers [2.40%, 5.18%, 6.86% (for Enc/XS, Ral/IS/XS, and IS/IS/XS) respectively; P  < 0.01]. Dry matter intake (DMI) was 2.3% greater (P  < 0.01) in steers administered Enc/XS compared to IS/IS/XS; however, DMI as a percentage of BW, average daily gain, and feed efficiency were not different (P  ≥ 0.12). Dressing percentage, hot carcass weight, heavy carcass occurrence, Longissimus muscle area, and 12th rib fat thickness were similar among all steers (P  ≥ 0.28). Marbling score tended to be greatest for Enc/XS and Ral/IS/XS (P  = 0.09). Enc/XS graded a greater proportion of USDA Prime and fewer USDA Select carcasses than IS/IS/XS (P  < 0.05). Enc/XS and Ral/IS/XS tended (P  = 0.09) to have more USDA Yield Grade (YG) 1 carcasses. While delayed administration or decreased total potency of TBA-containing implants may decrease buller incidence and improve Quality Grade, few differences were observed in live or carcass outcomes. [ABSTRACT FROM AUTHOR]

One hundred and twenty-one Angus × SimAngus-crossbred steers (body weight (BW) = 159 ± 22 kg) were used to evaluate the effects of different grain inclusion (GI) rates in diets provided to early-weaned calves and steroidal implants (SI) utilization on growth performance and carcass characteristics, particularly intramuscular fat deposition, of beef steers. The experiment was conducted as a randomized complete block design with a 2 × 2 factorial arrangement of treatments, consisting of two GI rates (35% vs. 58%, dry matter (DM) basis), each one associated or not to steroidal implant utilization (no implants vs. 80 mg trenbolone acetate (TA) + 16 mg estradiol followed by 120 mg TA + 24 mg of estradiol). After being early-weaned (124 ± 14 d of age), steers were offered an average of 4.5 kg/d (DM basis) of a concentrate-based diet with a greater or lesser GI rate for 60 d. After being fed a concentrate-based diet with different GI rates for 60 d, steers were fed a common backgrounding diet for 56 d and subsequently fed a common high-grain diet until harvested at a constant final BW (620 kg). Steers were not implanted until the beginning of the backgrounding phase and then re-implanted when initiating the finishing phase. Data were analyzed using PROC MIXED in SAS. There were no GI × SI interactions (P  ≥ 0.62) for any of the growth performance parameters throughout the experimental period. Implanted steers tended to have a greater average daily gain (P  = 0.10) during the finishing phase than nonimplanted steers. For the 12th rib fat thickness and yield grade (YG), a GI × SI interaction (P  = 0.03) and a tendency for a GI × SI interaction (P  = 0.10) was detected, respectively. Nonimplanted steers fed diets with greater GI rates presented the greatest 12th rib fat thickness and tended to have the greatest YG among treatments. No other interactions (P  ≥ 0.33) were observed for the hot carcass weight, Longissimus muscle (LM) area, quality grade, marbling score, and kidney-pelvic-heart fat content. Steers fed diets with lesser GI rates tended to have a greater LM area than steers fed diets with greater GI rates (P  = 0.10). Results from this experiment indicate that varying GI rates in diets provided to early-weaned calves and subsequent implantation with steroidal hormones did not affect marbling deposition. [ABSTRACT FROM AUTHOR]

The mature peptide of growth differentiation factor 11 (GDF11) in Bos taurus breeds, shares 90% amino acid sequence similarity to myostatin (MSTN), where loss-of-function mutations result in muscular hyperplasia causing a phenotype known as double-muscling. Mutations in the MSTN coding sequence increase muscle mass and reduce fat and bone tissues, but also confer poor fertility, reduced stress tolerance, and increased calf mortality. GDF11 influences skeletal muscle development in mice, and muscular atrophy can be induced by exogenous GDF11 treatment. To date, there are no reports of GDF11's role in bovine carcass traits. To determine associations between GDF11 and carcass quality in beef cattle, bovine GDF11 was examined in crossbred Canadian beef cattle populations during finishing. Few coding variants were found in this functionally important gene, but an upstream variant c.1-1951C > T (rs136619751) with a minor allele frequency of 0.31 was identified and further genotyped in two separate populations of crossbred steers (n  = 415 and 450). CC animals had lower backfat thickness, marbling percentage, and yield score than CT or TT animals (P <  0.001 and < 0.05). These data suggest a role of GDF11 in carcass quality in beef cattle and may provide a selection tool to improve carcass traits in cattle. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the influence of two low-stress weaning methods with conventional weaning on post-weaning performance and carcass characteristics of beef steers. Single-sourced steer calves (n = 89) were stratified by body weight (BW) and dam age into three groups in a completely randomized design (n = 29 or 30 steers/treatment): ABRUPT (calves isolated from dams on the day of weaning), FENCE (calves separated from dams via a fence for 7 d prior to completely weaning), and NOSE (nose-flap inserted and calves remained with dams for 7 d prior to completely weaning). At day +7 post-weaning, calves were transported to a commercial feedlot where they received standard step-up and finishing rations typical for a Northern Plains feedlot. BWs were recorded in study day −7 (PreTreat), 0 (Weaning), 7 (PostWean), 26 (Receiving), 175 (Ultrasound), and 238 or 268 (Final), and average daily gains (ADG) were calculated for each time period. Blood samples were collected via coccygeal venipuncture at d −7 (PreTreat), 0 (Weaning), and +7 (PostWean) from a subsample of calves (n = 10 per treatment) and analyzed for haptoglobin (acute-phase stress protein) concentrations using a bovine haptoglobin ELISA kit. On day 175, ultrasound fat thickness and intramuscular fat were determined and utilized to project marketing dates when steers reached 1.27 cm of backfat (day 238 or 268). Carcass measurements were recorded at the time of harvest. The weaning method interacted (P < 0.01) with a time period for ADG and BW. Calf ADG was greater (P < 0.01) in the NOSE treatment during PreTreat to Weaning than ABRUPT or FENCE. In the Weaning to PostWean period, the FENCE calves had greater (P < 0.01) ADG than ABRUPT and NOSE. During the Postwean to Receiving period ADG was greater (P < 0.04) for ABRUPT compared to FENCE and NOSE. Calf ADG was similar (P > 0.05) among treatments for the remainder of the feeding period. Calf BW did not differ among treatments (P > 0.05) at all times of weighing. Haptoglobin was undetectable in all samples except two samples collected on day −7. The weaning method did not influence (P > 0.05) carcass measurements. Collectively these data suggest low-stress weaning methods do not significantly improve post-weaning growth performance or carcass characteristics compared to using conventional methods despite minor, short-term alterations in ADG during the weaning period. [ABSTRACT FROM AUTHOR]