Evaluation of antimicrobial and non-steroidal anti-inflammatory treatments for BRD on health and welfare in fattening bulls: a cross-sectional study

Our study aimed to evaluate the effect of different treatments for BRD on health and welfare in fattening bulls. A total of 264 bulls were enrolled. Welfare was assessed on day 2 (T0) and day 15 (T1) after arrival. A decrease in the welfare level was observed from T0 to T1. All bulls were inspected clinically at T0 and T1 revealing an increase of skin lesions and lameness in T1. In both periods, a high incidence of respiratory disease was observed. A prevalence of 79.55% and 95.45% of Mycoplasma bovis using RT-PCR and culture at T0 and T1 respectively was observed. Blood samples were collected for haematology at T0 and T1. At T0, 36 animals were individually treated for BRD with an antimicrobial (IT), 54 received a metaphylactic treatment with tulathromycin (M), 150 received a metaphylactic treatment with tulathromycin plus a second antimicrobial (M + IT) whereas 24 were considered healthy and therefore not treated (NT). Additionally, 128 were treated with a non-steroid anti-inflammatory (NSAID). Neutrophils of M + IT were significantly higher than groups NT and M and the lymphocytes of M + IT were significantly lower than that of IT. White blood cells, neutrophils and N/L ratio of animals treated with an NSAID was significantly higher than that not treated. Lung inspection of 172 bulls at the abattoir indicated that 92.43% presented at least one lung lesion. A statistically significant effect of the NSAID treatment on the lung lesions was observed. Our findings indicate that BRD was a major welfare and health concern and evidence the difficulties of antimicrobial treatment of M. bovis.

Omega-3 Long-Chain Polyunsaturated Fatty Acids in Nonseafood and Estimated Intake in the USA: Quantitative Analysis by Covalent Adduct Chemical Ionization Mass Spectrometry

Omega-3 long-chain polyunsaturated fatty acids (LCPUFA) play critical roles in human development and health. Their intake is often effectively estimated solely based on seafood consumption, though the high intake of terrestrial animal-based foods with minor amounts of LCPUFA may be significant. Covalent adduct chemical ionization (CACI) tandem mass spectrometry is one approach for de novo structural and quantitative analysis of minor unsaturated fatty acids (FA), for which standards are unavailable. Here, CACI-MS and MS/MS are used to identify and quantify minor omega-3 LCPUFA of terrestrial animal foods based on the application of measured response factors (RFs) to various FA. American mean intakes of pork, beef, chicken, and eggs contribute 20, 27, 45, and 71 mg/day of docosahexaenoic acid (DHA), respectively. The estimated intake of omega-3 DHA, eicosapentaenoic acid, and docosapentaenoic acid from nonseafood sources is significant, at 164, 103, and 330 mg/day, greater than most existing estimates of omega-3 LCPUFA intake.

Higher Muscle Protein Synthesis Rates Following Ingestion of an Omnivorous Meal Compared with an Isocaloric and Isonitrogenous Vegan Meal in Healthy, Older Adults

BACKGROUND

Plant-derived proteins are considered to have fewer anabolic properties when compared with animal-derived proteins. The anabolic properties of isolated proteins do not necessarily reflect the anabolic response to the ingestion of whole foods. The presence or absence of the various components that constitute the whole-food matrix can strongly impact protein digestion and amino acid absorption and, as such, modulate postprandial muscle protein synthesis rates. So far, no study has compared the anabolic response following ingestion of an omnivorous compared with a vegan meal.

OBJECTIVES

This study aimed to compare postprandial muscle protein synthesis rates following ingestion of a whole-food omnivorous meal providing 100 g lean ground beef with an isonitrogenous, isocaloric whole-food vegan meal in healthy, older adults.

METHODS

In a randomized, counter-balanced, cross-over design, 16 older (65-85 y) adults (8 males, 8 females) underwent 2 test days. On one day, participants consumed a whole-food omnivorous meal containing beef as the primary source of protein (0.45 g protein/kg body mass; MEAT). On the other day, participants consumed an isonitrogenous and isocaloric whole-food vegan meal (PLANT). Primed continuous L-[ring-13C6]-phenylalanine infusions were applied with blood and muscle biopsies being collected frequently for 6 h to assess postprandial plasma amino acid profiles and muscle protein synthesis rates. Data are presented as means ± standard deviations and were analyzed by 2 way-repeated measures analysis of variance and paired-samples t tests.

RESULTS

MEAT increased plasma essential amino acid concentrations more than PLANT over the 6-h postprandial period (incremental area under curve 87 ± 37 compared with 38 ± 54 mmol·6 h/L, respectively; P-interaction < 0.01). Ingestion of MEAT resulted in ∼47% higher postprandial muscle protein synthesis rates when compared with the ingestion of PLANT (0.052 ± 0.023 and 0.035 ± 0.021 %/h, respectively; paired-samples t test: P = 0.037).

CONCLUSIONS

Ingestion of a whole-food omnivorous meal containing beef results in greater postprandial muscle protein synthesis rates when compared with the ingestion of an isonitrogenous whole-food vegan meal in healthy, older adults. This study was registered at clinicaltrials.gov as NCT05151887.

Consumption of beef sandwiches in the United States and contributions to intake of energy and select nutrients

Introduction

Sandwiches are commonly consumed in the United States. This study summarizes contributions of beef sandwiches to energy and select nutrient intakes.

Methods

Beef sandwiches were categorized as beef burger sandwiches (hamburgers or cheeseburgers) and non-burger beef sandwiches. Per capita and per user consumption of beef sandwiches (total and by type) and contributions to total nutrient intakes from beef and non-beef sandwich components were estimated for the population ages ≥2 years (n = 15,984) participating in WWEIA/NHANES, 2013-2016.

Results

On any given day, 21.4% of the population consumed a beef sandwich. Among all Americans, beef sandwiches provided 6.3% of mean energy intake and accounted for approximately 10% of the population's mean intake of vitamin B12 and saturated fat, 9% of protein and sodium, 7% of iron, 6% of choline, and 5% of potassium. Among beef sandwich consumers, beef sandwiches accounted for 26.2% of mean energy intake on a day of consumption. The beef component of sandwiches accounted for the majority of vitamin B12, choline, and protein, non-beef components accounted for the majority of sodium, iron, and potassium, and beef and non-beef components made similar contributions to saturated fat. Hamburgers provided consumers the lowest energy, sodium, and saturated fat intake, while non-burger sandwiches provided the highest intake of these nutrients.

Discussion

Beef sandwiches are an important source of energy, protein, vitamin B12, iron, and choline, and like other sandwiches, are also a source of sodium and saturated fat. Americans could enhance nutrient contributions from sandwiches by selecting lean meat and limiting use of saturated fat- or sodium-rich non-beef components.

The Concentration of Benzo[a]pyrene in Food Cooked by Air Fryer and Oven: A Comparison Study

The air fryer utilizes heated air rather than hot oil to achieve frying, eliminating the need for cooking oil, rendering it a healthier cooking method than traditional frying and baking. However, there is limited evidence supporting that the air fryer could effectively reduce the level of food-derived carcinogen. In this study, we compared the concentration of Benzo[a]pyrene (BaP), a typical carcinogen, in beef patties cooked using an air fryer and an oven, under different cooking conditions, including temperatures (140 °C, 160 °C, 180 °C, and 200 °C), times (9, 14, and 19 min), and oil added or not. The adjusted linear regression analysis revealed that the BaP concentration in beef cooked in the air fryer was 22.667 (95% CI: 15.984, 29.349) ng/kg lower than that in beef cooked in the oven. Regarding the air fryer, the BaP concentration in beef cooked without oil brushing was below the detection limit, and it was significantly lower than in beef cooked with oil brushing (p < 0.001). Therefore, cooking beef in the air fryer can effectively reduce BaP concentration, particularly due to the advantage of oil-free cooking, suggesting that the air fryer represents a superior option for individuals preparing meat at high temperatures.

Red and Red Processed Meat Consumption Behaviors in Scottish Adults

In 2021, 32% of adult meat consumers in Scotland exceeded the 70 g/d recommended limit of red and red processed meat (RPM) intake. We analyzed RPM consumption behaviors among adults in the Scottish Health Survey (2021) to better understand this consumer group. Consumers were categorized into low, medium, and high consumers, and overall, mean intake was 66 g/d. Males and individuals living in the most deprived areas were most likely to be high consumers (45% compared with 30% for males compared with females, respectively, and 44% compared with 32% for those in the most compared with least deprived areas, respectively). Dinners accounted for the majority of intake among high (55%) and medium (52%) consumers, whereas low consumers distributed intake between lunch (40%) and dinner (48%). Across all groups, consumption was highest on Sundays, and majority of RPM was purchased at supermarkets. Beef dishes and sandwiches were primary contributors among high and medium consumers. These insights can inform the design of effective strategies and policies aligned with meat reduction targets. For instance, strategies focusing on modifying traditional meat-centric dishes and sandwiches could be impactful.

Modeling of Ethiopian Beef Meat Marbling Score Using Image Processing for Rapid Meat Grading

Meat characterized by a high marbling value is typically anticipated to display enhanced sensory attributes. This study aimed to predict the marbling scores of rib-eye, steaks sourced from the Longissimus dorsi muscle of different cattle types, namely Boran, Senga, and Sheko, by employing digital image processing and machine-learning algorithms. Marbling was analyzed using digital image processing coupled with an extreme gradient boosting (GBoost) machine learning algorithm. Meat texture was assessed using a universal texture analyzer. Sensory characteristics of beef were evaluated through quantitative descriptive analysis with a trained panel of twenty. Using selected image features from digital image processing, the marbling score was predicted with R2 (prediction) = 0.83. Boran cattle had the highest fat content in sirloin and chuck cuts (12.68% and 12.40%, respectively), followed by Senga (11.59% and 11.56%) and Sheko (11.40% and 11.17%). Tenderness scores for sirloin and chuck cuts differed among the three breeds: Boran (7.06 ± 2.75 and 3.81 ± 2.24, respectively), Senga (5.54 ± 1.90 and 5.25 ± 2.47), and Sheko (5.43 ± 2.76 and 6.33 ± 2.28 Nmm). Sheko and Senga had similar sensory attributes. Marbling scores were higher in Boran (4.28 ± 1.43 and 3.68 ± 1.21) and Senga (2.88 ± 0.69 and 2.83 ± 0.98) compared to Sheko (2.73 ± 1.28 and 2.90 ± 1.52). The study achieved a remarkable milestone in developing a digital tool for predicting marbling scores of Ethiopian beef breeds. Furthermore, the relationship between quality attributes and beef marbling score has been verified. After further validation, the output of this research can be utilized in the meat industry and quality control authorities.

Ammonia-Responsive Colorimetric Film of Phytochemical Formulation (Alizarin) Grafted onto ZIF-8 Carrier with Poly(vinyl alcohol) and Sodium Alginate for Beef Freshness Monitoring

In this study, we devised a photothermally stable phytochemical dye by leveraging alizarin in conjunction with the metal-organic framework ZIF-8 (AL@ZIF-8). The approach involved grafting alizarin into the microporous structure of ZIF-8 through physical adsorption and hydrogen-bonding interactions. AL@ZIF-8 significantly enhanced the photostability and thermostability of alizarin. The nanoparticles demonstrate substantial color changes in various pH environments, showcasing their potential for meat freshness monitoring. Furthermore, we introduced an intelligent film utilizing poly(vinyl alcohol)-sodium alginate-AL@ZIF-8 (PA-SA-ZA) for detecting beef freshness. The sensor exhibited a superior water contact angle (52.34°) compared to the alizarin indicator. The color stability of the film was significantly enhanced under visible and UV light (ΔE < 5). During beef storage, the film displayed significant color fluctuations correlating with TVB-N (R2=0.9067), providing precise early warning signals for assessing beef freshness.

The Effects of Assisted Freezing with Different Ultrasound Power Rates on the Quality and Flavor of Braised Beef

This study investigated the effects of ultrasound-assisted immersion freezing (UIF) at different power rates (0, 200, 400, and 600 W) on the changes in beef quality and flavor after braising. The results demonstrated that UIF treatment at 400 W significantly reduced the juice loss (cooking loss decreased from 49.04% to 39.74%) and fat oxidation (TBARS value decreased from 0.32 mg/kg to 0.20 mg/kg) of braised beef. In addition, the tenderness (hardness value decreased from 5601.50 g to 2849.46 g) and color stability of braised beef were improved after UIF treatment. The flavor characteristics of braised beef were characterized using an electronic nose and an electronic tongue. The PCA analysis data showed that the cumulative contribution rates of the first and second principal components were 85% and 93.2%, respectively, with the first principal component accounting for a higher proportion. The UIF-400 W group had the highest concentration for the first principal component, and the differentiation was not significant compared to the control group. The total amino acid values of different power UIF treatment groups were improved compared to the AF treatment group, indicating that UIF can effectively reduce the losses caused by freezing. The results demonstrate that ultrasound-assisted freezing treatment is beneficial in enhancing the tenderness and flavor attributes of beef after braising, providing new insights into the processing of meat products with desirable quality characteristics.

Study on the Correlations between Quality Indicators of Dry-Aged Beef and Microbial Succession during Fermentation

Dry-aged beef has been long favored by people due to its unique flavor and taste. However, the inner relationship between its overall quality formation and microbial changes during dry aging has not yet received much attention and research. To deeply reveal the forming mechanism of the unique flavor and taste of dry-aged beef, correlations between its three main quality indicators, i.e., texture, free amino acids (FAAs), volatile flavor compounds (VFCs), and microbial succession were analyzed in this study. The results showed that Staphylococcus spp. and Macrococcus spp. were key strains that influenced the total quality of dry-aged beef and strongly correlated with chewiness, hardness, and sweet FAAs (Ala), providing beef with unique palatability and taste. Additionally, among VFCs, Staphylococcus spp. and Macrococcus spp. showed a strong correlation with octanal and heptanal, and meanwhile, those highly correlated with nonanal, pentanol, and oct-1-en-3-ol were Debaryomyces spp., Psychrobacter spp., and Brochothrix spp., respectively, providing beef with a unique flavor. Staphylococcus spp. was proposed to be the dominant genus for dry-aged beef. This study provides valuable reference for the understanding of the role of microorganisms involved in dry aging.

Acerola Cherry and Rosemary Extracts Improve Color and Delay Lipid Oxidation in Previously Frozen Beef

Extending the shelf life of exported beef could increase international demand and producer profits. The objective was to evaluate the effects of topically applying combinations of acerola cherry powder and rosemary extract on the shelf life of frozen-thawed bone-in beef short rib and chuck roll steaks. Chuck rolls (IMPS 116A; N = 9) and bone-in short ribs (IMPS 123A; N = 18) were aged (7 d; 0 °C), frozen (30 d; -20 °C), and thawed (60-72 h; 0 °C). Steaks measuring 1.02 cm thick were treated and subjected to a 4 d retail display. Steaks were left untreated (control) or sprayed topically with acerola cherry powder (0.05%; A), rosemary extract (0.10%; R), or a combination (M1 = 0.05% A + 0.1% R; M2 = 0.1% A + 0.1% R; M3 = 0.05% A + 0.2% R; M4 = 0.1% A + 0.2% R). Chuck roll M2- and M4-treated steaks were redder than the control steaks on days 3 and 4 (p = 0.008), and antioxidant-treated steaks had less lipid oxidation on day 4 than the control steaks (p = 0.021). Bone marrow samples treated with R, M3, and M4 were redder than the control on days 1-3 (p = 0.014), and bone marrow treated with M3 was subjectively redder compared to the control on days 0 and 1 (p = 0.033). Topical antioxidants improve the redness and delay the oxidation of frozen-thawed beef.

The Role of Fresh Beef Intake and Mediterranean Diet Adherence during Pregnancy in Maternal and Infant Health Outcomes

Beef is an excellent source of nutrients important for maternal health and fetal development. It is also true that the Mediterranean diet is beneficial for the health of both the mother and offspring; however, the relative value of fresh beef intake within Mediterranean diet patterns during pregnancy is unknown. The objective of this project was two-fold: (1) assess the relationship between beef intake and nutrient intake in a pregnant population; (2) assess the relationship between maternal beef consumption among varying degrees of Mediterranean diet adherence with maternal risk of anemia and infant health outcomes. This is a secondary analysis of an existing cohort of pregnant women (n = 1076) who participated in one of two completed clinical trials examining the effect of a docosahexaenoic acid supplementation on birth and offspring outcomes. Women were enrolled between 12 and 20 weeks of gestation and were followed throughout their pregnancies to collect maternal and infant characteristics, food frequency questionnaires [providing beef intake and Mediterranean diet (MedD) adherence], and supplement intake. Women with the highest fresh beef intake had the highest intake of many micronutrients that are commonly deficient among pregnant women. Fresh beef intake alone was not related to any maternal or infant outcomes. There was a reduced risk of anemia among women with medium to high MedD quality and higher fresh beef intake. Women in the medium MedD group had 31% lower odds of anemia, and women in the high MedD group had 38% lower odds of anemia with every one-ounce increase in fresh beef intake, suggesting that diet quality indices may be misrepresenting the role of fresh beef within a healthy diet. These findings show that beef intake increases micronutrient intake and may be protective against maternal anemia when consumed within a healthy Mediterranean diet pattern.

Detection of selected antimicrobial residues in red meat and kidney of beef cattle slaughtered at Nekemte municipal abattoir, Ethiopia

BACKGROUND

Antibiotics are commonly used drugs in farm animals for therapeutic, prophylactic and diagnosis purposes. As a result of the use of antibiotics in livestock, residues of antibiotics may be present in animal-derived foods, especially in meat. This study aimed at determining the antibiotic residues in cattle slaughtered at Nekemte municipal abattoir and assessing the knowledge, attitude and practice (KAP) level of the community about antibiotic residue in food of cattle origin.

MATERIALS AND METHODS

A cross-sectional study was conducted on randomly selected kidney and muscle samples slaughtered at Nekemte municipal abattoir. The samples were collected aseptically and analysed using liquid chromatography mass spectrometer. In addition the KAP of cattle handlers, butcher men and meat users were collected using structured questionnaire. The data was analysed by SPSS and intercooled Stata version 7.0, 2001.

RESULTS

Results are presented as percentages and frequency distributions in tabular and graphical form. From 120 individuals interviewed, only 25.83% knew about withdrawal time and had limited knowledge on effect of antibiotic residue on human health, whereas about 47.5% did not heard about antibiotic residue in meat. Tetracycline was detected in all the sampled meat 60 (100%), whereas oxytetracycline residues were detected in half 15 (50%) of the samples. In the current study doxycycline, sulphadiazine, penicillin G and enrofloxacin were not detected in all samples. Oxytetracycline residue levels ranged from 0.00 to 463.35 µg/kg for the kidney and 0.00 to 354.55 µg/kg for muscle samples. About 10% of kidney and 3.33% muscle samples collected had oxytetracycline residues above maximum residue limits.

CONCLUSION

In general, the study revealed that oxytetracycline residues were prevalent among antimicrobial residues analysed from the study area. The study indicated the presence of high antimicrobial residue and hence exposes for antimicrobial resistance of pathogens warranting coordinated effort to mitigate its health effect on the animal and hence human being.

Depth of Interbreed Difference in Postmortem Bovine Muscle Determined by CE-FT/MS and LC-FT/MS Metabolomics

Japanese Brown (JBR) cattle have moderately marbled beef compared to the highly marbled beef of Japanese Black (JBL) cattle; however, their skeletal muscle properties remain poorly characterized. To unveil interbreed metabolic differences over the previous results, we explored the metabolome network changes before and after postmortem 7-day aging in the trapezius muscle of the two cattle breeds by employing a deep and high-coverage metabolomics approach. Using both capillary electrophoresis (CE) and ultra-high-performance liquid chromatography (UHPLC)-Fourier transform mass spectrometry (FT/MS), we detected 522 and 384 annotated peaks, respectively, across all muscle samples. The CE-based results showed that the cattle were clearly separated by breed and postmortem age in multivariate analyses. The metabolism related to glutathione, glycolysis, vitamin K, taurine, and arachidonic acid was enriched with differentially abundant metabolites in aged muscles, in addition to amino acid (AA) metabolisms. The LC-based results showed that the levels of bile-acid-related metabolites, such as tauroursodeoxycholic acid (TUDCA), were high in fresh JBR muscle and that acylcarnitines were enriched in aged JBR muscle, compared to JBL muscle. Postmortem aging resulted in an increase in fatty acids and a decrease in acylcarnitine in the muscles of both cattle breeds. In addition, metabolite set enrichment analysis revealed that JBR muscle was distinctive in metabolisms related to pyruvate, glycerolipid, cardiolipin, and mitochondrial energy production, whereas the metabolisms related to phosphatidylethanolamine, nucleotide triphosphate, and AAs were characteristic of JBL. This suggests that the interbreed differences in postmortem trapezius muscle are associated with carnitine/acylcarnitine transport, β-oxidation, tricarboxylic acid cycle, and mitochondrial membrane stability, in addition to energy substrate and AA metabolisms. These interbreed differences may characterize beef quality traits such as the flavor intensity and oxidative stability.

Evaluating disinfectant efficacy on mixed biofilms comprising Shiga toxigenic Escherichia coli, lactic acid bacteria, and spoilage microorganisms

This study aimed to investigate the impact of temperature and the presence of other microorganisms on the susceptibility of STEC to biocides. Mature biofilms were formed at both 10°C and 25°C. An inoculum of planktonic bacteria comprising 106 CFU/mL of spoilage bacteria and 103 CFU/mL of a single E. coli strain (O157, O111, O103, and O12) was used to form mixed biofilms. The following bacterial combinations were tested: T1: Carnobacterium piscicola + Lactobacillus bulgaricus + STEC, T2: Comamonas koreensis + Raoultella terrigena + STEC, and T3: Pseudomonas aeruginosa + C. koreensis + STEC. Tested biocides included quaternary ammonium compounds (Quats), sodium hypochlorite (Shypo), sodium hydroxide (SHyd), hydrogen peroxide (HyP), and BioDestroy®-organic peroxyacetic acid (PAA). Biocides were applied to 6-day-old biofilms. Minimum Bactericidal Concentrations (MBC) and Biofilm Eradication Concentrations (BEC) were determined. Planktonic cells and single-species biofilms exhibited greater susceptibility to sanitizers (p < 0.0001). Lactobacillus and Carnobacterium were more susceptible than the rest of the tested bacteria (p < 0.0001). Single species biofilms formed by E. coli O111, O121, O157, and O45 showed resistance (100%) to Shypo sanitizer (200 ppm) at 25°C. From the most effective to the least effective, sanitizer performance on single-species biofilms was PAA > Quats > HyP > SHyd > Shypo. In multi-species biofilms, spoilage bacteria within T1, T2, and T3 biofilms showed elevated resistance to SHyd (30%), followed by quats (23.25%), HyP (15.41%), SHypo (9.70%), and BioDestroy® (3.42%; p < 0.0001). Within T1, T2, and T3, the combined STEC strains exhibited superior survival to Quats (23.91%), followed by HyP (19.57%), SHypo (18.12%), SHyd (16.67%), and BioDestroy® (4.35%; p < 0.0001). O157:H7-R508 strains were less tolerant to Quats and Shypo when combined with T2 and T3 (p < 0.0001). O157:H7 and O103:H2 strains in mixed biofilms T1, T2, and T3 exhibited higher biocide resistance than the weak biofilm former, O145:H2 (p < 0.0001). The study shows that STEC within multi-species biofilms' are more tolerant to disinfectants.

Influence of breed and environment on leukocyte telomere length in cattle

High milk yield is associated with reduced longevity in high-producing dairy cattle breeds. Pre-term culling leads to high replacement heifer demand and economic losses for the dairy industry. Selection for this trait is limited because of low heritability and difficulties in phenotype measurement. Telomeres are elements found at the ends of chromosomes, consisting of repetitive DNA sequences, several thousand base pairs in length, coupled with nucleoprotein complexes. Eventually, in humans and most other animals, telomere length reduces with age. When telomeric DNA is truncated to a critical length, cell ageing, cell cycle arrest, and apoptosis are induced. As a result, telomere length can be considered as a predictor of health risks and an individual's lifespan. The leukocyte telomere length may be used as a proxy phenotype of productive lifespan to improve cattle selection. Our objectives were to assess the effects of breed and breed group (dairy vs. beef) on the leukocyte telomere length and to estimate the effect of cold climate on this trait in Kalmyk cattle populations from the South (Rostov Oblast) and Far North (Republic of Sakha) regions of Russia. The leukocyte telomere lengths were estimated computationally from whole-genome resequencing data. We leveraged data on leukocyte telomere length, sex, and age of 239 animals from 17 cattle breeds. The breed factor had a significant effect on leukocyte telomere length across our sample. There was no difference in leukocyte telomere length between dairy and beef groups. The population factor had a significant effect on leukocyte telomere length in Kalmyk animals. In conclusion, we found that breed, but not breed group (dairy vs. beef), was significantly associated with leukocyte telomere length in cattle. Residence in colder climates was associated with longer leukocyte telomere length in Kalmyk breed cattle.

Waste not, want not: Value chain stakeholder attitudes to surplus dairy calf management in Australia

The management of surplus dairy calves in Australia has traditionally been influenced by the economic viability of different practices. When beef prices are favourable, more surplus calves are raised for beef, and when beef prices are low, more calves are killed in the first few days of life. Early life killing of surplus calves may however threaten the dairy industry's social licence to operate. The aim of this study was to describe the views of value chain stakeholders regarding the management of surplus calves. Representatives from seven post-farm gate organisations participated in semi-structured interviews and were asked about their views on current practices, alternatives to early life killing and how best to implement change. Responses were analysed using inductive thematic analysis and were organised into three themes: (1) ethics of surplus calf management; (2) economics of surplus calf management; and (3) moving towards solutions including approaches to affecting change. We conclude that stakeholders widely recognised early life killing of surplus calves as a threat to the industry's social licence. Whilst technical solutions such as beef on dairy breeding programmes were cited as important, participants emphasised that implementing sustainable solutions will require collaboration, leadership, and commitment by all stakeholders along the value chain.

Molecular and Cellular Mechanisms of Intramuscular Fat Development and Growth in Cattle

Intramuscular fat, also referred to as marbling fat, is the white fat deposited within skeletal muscle tissue. The content of intramuscular fat in the skeletal muscle, particularly the longissimus dorsi muscle, of cattle is a critical determinant of beef quality and value. In this review, we summarize the process of intramuscular fat development and growth, the factors that affect this process, and the molecular and epigenetic mechanisms that mediate this process in cattle. Compared to other species, cattle have a remarkable ability to accumulate intramuscular fat, partly attributed to the abundance of sources of fatty acids for synthesizing triglycerides. Compared to other adipose depots such as subcutaneous fat, intramuscular fat develops later and grows more slowly. The commitment and differentiation of adipose precursor cells into adipocytes as well as the maturation of adipocytes are crucial steps in intramuscular fat development and growth in cattle. Each of these steps is controlled by various factors, underscoring the complexity of the regulatory network governing adipogenesis in the skeletal muscle. These factors include genetics, epigenetics, nutrition (including maternal nutrition), rumen microbiome, vitamins, hormones, weaning age, slaughter age, slaughter weight, and stress. Many of these factors seem to affect intramuscular fat deposition through the transcriptional or epigenetic regulation of genes directly involved in the development and growth of intramuscular fat. A better understanding of the molecular and cellular mechanisms by which intramuscular fat develops and grows in cattle will help us develop more effective strategies to optimize intramuscular fat deposition in cattle, thereby maximizing the quality and value of beef meat.

Sympatric occurrence of Taenia saginata and Sarcocystis spp. in cattle from Narok County, Kenya: meat inspection findings with molecular validation

The epidemiological picture of Taenia saginata infections in Kenya is fragmented with limited available data. Although Sarcocystis species are significant meat-borne parasites, few studies have explored their occurrence in Kenya. This study aimed to estimate the occurrence of bovine cysticercosis and screen for the presence of Sarcocystis spp. A meat inspection-based survey was conducted in ten abattoirs in Narok County, Kenya, and inspection for T. saginata cysticerci was limited to the Triceps brachii muscle. The apparent occurrence of the parasite was 5.4% (95% CI, 3.8, 7.6, n=573). Molecular confirmation of T. saginata was done via nested polymerase chain reaction targeting the mitochondrial 12S ribosomal RNA gene and restricted fragment length polymorphism. Sarcocystis species were identified using a multiplex polymerase chain reaction method targeting the 18S ribosomal RNA gene sequences and the mitochondrial cytochrome c oxidase subunit I gene. Of the 31 cystic lesions tested, 26/31 (83.9%) were confirmed to be T. saginata.Sarcocystis cruzi and S. hominis were detected in 8/31 (25.8%) and 1/31 (3.2%) of the cystic lesions, respectively. Co-infections of S. cruzi and T. saginata were found in 6/31 lesions (19.4%). The confirmation of bovine cysticercosis and S. hominis is suggestive of the presence of risky culinary and sanitation practices that facilitate transmission. This is the first report and molecular confirmation of Sarcocystis spp. in cattle in the country. The presence of both zoonotic S. hominis and pathogenic S. cruzi highlights an underexplored concern of veterinary and human health significance, warranting further epidemiological investigation.

Effects of Zilpaterol Hydrochloride Supplementation on Growth Performance, Carcass Characteristics and Meat Quality for Steers Differing in Breed Type

To determine the effects of zilpaterol hydrochloride (ZH) on growth performance, carcass characteristics and meat quality for steers differing in breed type, steers with British (B; n = 76) or British × Continental (BC; n = 57) backgrounds were allocated to a randomized incomplete block design with a 2 × 2 treatment structure. Pens within each block × breed type were randomly assigned to either ZH (8.3 mg/kg of DM; fed for 20 d before slaughter, followed by a 3-day withdrawal) or control (CON; 0 mg/kg ZH). Steers were subjected to ultrasound immediately before ZH inclusion and following withdrawal to determine the influence of ZH on changes in longissimus muscle area (LMA), fat thickness and percent intramuscular fat (IMF). Carcass data were collected, and the longissimus lumborum was collected for analysis of tenderness, moisture percentage, crude fat content, collagen content, postmortem proteolysis and sensory attributes. The ZH × breed type interaction did not influence (p > 0.05) the feedlot performance, carcass or meat quality attribute traits evaluated, with the exception of moisture percentage. Responses among breed types were as expected for B vs. BC cattle types. Supplementation with ZH improved (p < 0.05) LMA and yield grade but increased Warner-Bratzler shear force.

Effect of Lighter and Heavier Initial Weight on Growth Performance and Carcass Traits of Single-Source Beef Steers

The objective of the study was to determine the influence that initial BW has on growth performance responses, efficiency of dietary net energy (NE) utilization, and carcass traits in feedlot steers. Charolais×Red Angus steers (n = 70) selected from a larger single-source group were used in a 209-d growing-finishing feedlot experiment. Steers were assigned to two groups based on initial BW (light initial weight, LIW = 273 ± 16.0 kg; heavy initial weight, HIW = 356 ± 14.2 kg) and allotted into 10 pens (n = 7 steers per pen; 5 pens per experimental group) the within pen standard deviation for LIW was from 14.1 kg to 20.9 kg and for HIW was from 13.7 kg to 16.0 kg. Steers were fed a common diet once daily. Experimental data were analyzed as a randomized complete block design with pen as the experimental unit. LIW steers had a greater cumulative HH change (p = 0.04). A treatment × day interaction (p = 0.05) was observed for HH with HIW steers having a greater HH at all time points. Final BW and carcass-adjusted (HCW/0.625) BW were greater for HIW steers by 13.1% and 13.4% respectively (p ≤ 0.01). HIW steers had a greater DMI (p = 0.01) compared to LIW. Cumulative ADG was greater for HIW by 3% (p = 0.04). LIW steers had better feed conversion (p = 0.01). HIW steers had greater (p ≤ 0.05) HCW, marbling scores, and yield grade (YG), with decreased REA/HCW (p = 0.01) compared to LIW. The distribution of USDA Yield Grade was altered by initial BW (p = 0.04). No differences were detected (p ≥ 0.22) for the distribution of Quality grade nor liver abscess prevalence and severity. Regression coefficients did not differ between LIW and HIW for urea space calculations of empty body water, fat, or protein (p ≥ 0.70). A quadratic response was noted for empty body fat (EBF), empty body water (EBH20), and carcass protein (CP). In conclusion, HIW steers had greater growth, but poorer feed efficiency compared to LIW steers. Steers with a HIW produced fatter carcasses with a greater degree of marbling.

Effect of Post-Weaning Concentrate Feeding Prior to Forage Finishing on Intramuscular Fat Deposition

The objectives of this study were to examine the effects of feeding high-concentrate diets post-weaning (PW) prior to forage finishing on (1) changes in ultrasound intramuscular fat deposition and lipogenic/lipolytic gene expression during the post-weaning phase and (2) carcass characteristics and fatty acid composition after forage finishing to 487 kg. Steers were randomly assigned to one of four treatments (PW0, PW40, PW80, and PW120) at weaning to examine the time of high-concentrate feeding prior to forage finishing. The ultrasound intramuscular fat content was greater (p < 0.05) for PW120 compared to those for PW0, PW40, or PW80 at the end of the post-weaning phase. Feeding high concentrates (PW120) up-regulated (p < 0.01) the mRNA expression of fatty acid transporters and lipogenic genes and down-regulated lipolytic genes in the LM compared to PW0. Carcasses from PW120 were graded 83% Choice (p = 0.025), whereas carcasses from other post-weaning treatments (PW0, 40, or 80) were graded 25, 36, and 54% Choice, respectively, at the final harvest. The total fatty acid content of the muscle at slaughter was greater (p = 0.0004) for PW120 than PW0, PW40, and PW80. Feeding high-concentrate diets to steers post-weaning for 120 day enhanced early intramuscular fat deposition without causing major changes to the fatty acid composition of the longissimus muscle after forage finishing.

Effect of beef long-storage under different temperatures and vacuum-packaging conditions on meat quality, oxidation processes and microbial growth

BACKGROUND

The global beef market demands the meat industry to ensure product quality and safety in markets that are often very distant. The present study aimed to evaluate the effects of chilled (CH, 120 d) and chilled-then-frozen (CHF, 28 d + 92 d) storage conditions of beef vacuum packaged (VP) and vacuum packaged with antimicrobial (VPAM) on meat quality, oxidative status and microbial loads. Treatments resulted from the combination of storage condition and packaging type: VP + CH, VP + CHF, VPAM + CH and VPAM + CHF.

RESULTS

Warner-Bratzler shear force values decreased in all treatments after 28 d of chilling. Except for VP + CH, L* values (lightness) of meat color did not differ in each treatment as the storage time increased. Meat from VP + CH had greater a* values than CHF treatments on day 120 of storage. A consumer panel did not detect differences in tenderness, flavor and overall liking between VP and VPAM beef, but they preferred CHF steaks rather than CH beef. TBARS values did not differ between VP and VPAM and between CH and CHF at any time during the storage period. At the end of storage time, all treatments except VP + CHF presented a greater concentration of thiols than at 48 h post-mortem. On day 120 of storage, VP + CH had greater catalase enzyme activity than CHF treatments while VP + CH and VP + CHF showed a greater superoxide dismutase activity than VPAM + CHF. Storage condition (CH or CHF) had a greater impact on microbial counts than the type of packaging.

CONCLUSION

Freezing meat after an ageing period represents a suitable strategy to extend beef storage life without a detrimental impact on its quality. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Muscle Hypertrophy Is Linked to Changes in the Oxidative and Proteolytic Systems during Early Tenderization of the Spanish Breed "Asturiana de los Valles"

For fresh meat consumers, eating satisfaction is of utmost importance and tenderness is one of the most important characteristics in this regard. Our study examined beef of different animal biotypes of the autochthonous breed "Asturiana de los Valles" (AV) to determine if early postmortem oxidative and proteolytic processes may influence the final tenderness of the product. This meat-specialized breed shows different biotypes depending on the frequency of a myostatin mutation "mh" that induces double-muscling or muscular hypertrophy (mh/mh, mh/+, +/+). Samples from the longissimus dorsi muscles of yearling bulls were analyzed during the first 24 h postmortem. Changes in the redox balance of muscle cells were significant in the first hours after slaughter; total antioxidant activity was higher in the mh/mh biotype and it followed the shortening of the sarcomeres, a key parameter in understanding meat tenderness. The two proteolytic systems studied (proteasome and lysosome) followed distinct patterns. Proteasome activity was higher in the (mh/+) biotype, which correlated with higher protein damage. Lysosome proteolysis was increased in the more tender biotypes (mh genotypes). Autophagic activation showed significant differences between the biotypes, with (mh/mh) showing more intense basal autophagy at the beginning of the postmortem period that decreased gradually (p < 0.001), while in the normal biotype (+/+), it was slightly delayed and then increased progressively (p < 0.001). These results suggest that this type of catalytic process and antioxidant activity could contribute to the earlier disintegration of the myofibers, particularly in the mh/mh biotypes, and influence the conversion of muscle into meat.