Single Carcass Research Articles

Non destructive qualification of bovine meat tenderness

Tenderness is one of the most important criteria in bovine meat, as it determines whether the meat is used for grilling, long-time cooking or post-processing. It is therefore of great interest for the industry to measure it. Common systems require the extraction and destruction of samples, inducing time and material expenses. In this article, a new nondestructive characterization apparatus, based on monitored indentation, relaxation, and recovery, is proposed. Samples from two cuts known for their difference in tenderness were used from the same carcass. Their tenderness were assessed via compression tests and then compared to indicators from the force–displacement measurements. Results showed that the indentation and recovery speed, and the force relaxation enable the differentiation of the two cuts (p<0.05). These results were obtained on samples from a single carcass. Measurements on other carcasses should be performed to ensure that the results presented in this article can be generalized to bovine meat.

Forensic taphonomic experimental design matters: a study assessing clothing and carrion biomass load on scavenging in Cape Town, South Africa

The identification of unknown human remains is a significant and ongoing challenge in South Africa, worsened by the country’s high murder rate. The rate of decomposition in South Africa is significantly influenced by vertebrate scavenging, which, if not considered, can impede the accurate estimation of the post-mortem interval. Scavenging patterns vary greatly depending on the environment and ecological region, and there is limited data for the Western Cape province. To address this gap, two clothed and uncaged pig carcasses weighing 60 kg each were placed in the field in July 2021 and January 2022, respectively. Motion-activated infrared-capable trail cameras were used to observe decomposition, scavenger species, and their activities. Additionally, a comparative sample of 16 unclothed carcasses deployed between 2014 and 2016 in the same habitat were analyzed to assess the impact of clothing and biomass load. The study found three main results: (1) Regardless of habitat or biomass load, it took significantly less time to reach decomposition milestones (25%, 50%, and 75%) during the summer season; (2) the presence of mongoose scavengers had a greater impact on the time required to reach milestones during winter compared to summer; and (3) single carcass deployments reached the milestones faster than multi-carcass deployments in both seasons. This research highlights the potential inaccuracy of current methods for estimating the post-mortem interval when scavenging activity is not considered or documented in the underlying experimental data, particularly for environments or ecological biomes where scavengers actively impact decomposition rates.

Refining decomposition stage estimation: A study of seasonal insect composition and carcass weight change

AbstractIn this study, we explore the interplay of seasonal insect assemblages and carcass weight change to refine the estimation of minimum post‐mortem interval (PMImin), a key variable in forensic investigations. By integrating these parameters, we shed light on their combined influence on decomposition stages, thus paving the way for a more robust method of PMImin estimation. Our approach relies on rigorous field studies examining pig carcasses across spring, summer and autumn, with comprehensive measurements of carcass weight and detailed documentation of insect succession. We observed distinct insect assemblages and weight‐change trends characteristic of each season, underlining the influence of seasonal variability on decomposition dynamics. To further enhance the reliability of our model, we combined the novel parameter of carcass weight change with the conventional total body score (TBS) method, ensuring a more objective assessment of decomposition stages. Although our study indicates promising advancements, it also acknowledges the limitations of using a single pig carcass per season, suggesting future research should incorporate larger sample sizes.

Responses of necrophilous beetles to animal mass mortality in the Australian Alps

A diversity of insects can be found at the remains of dead animals (carrion) and they play a vital role in its decomposition and recycling. An emerging global problem with carrion is animal mass mortality events – the sudden, rapid die-off of many animals resulting in a large increase to the localised carrion resource pool. Yet, little is known about how insects respond to sudden and large inputs of carrion. We conducted an experiment in a mountainous alpine region of south-eastern Australia and compared beetle assemblages found at single carcass and mass mortality sites. We also examined the effects of vertebrate exclusion, and decomposition stage on beetles. We found 4,774 beetles representing 146 different species/morphospecies from 17 families. The most abundant species was Saprinus cyaneus cyaneus (Histeridae), and species of Staphylinidae and Silphidae also dominated the fauna, which is typical for necrophilous beetles in Australia. We also found a clear temporal change in beetle assemblages, with abundance and richness peaking during the active decay stage. We found that beetle abundance was greater at single carcasses than mass mortality sites, possibly as an artifact of sampling, and that species richness was similar among these two carcass treatment types. We found no significant effect of vertebrate exclusion on beetles, suggesting that large scavengers in the study system may not influence necrophilous insect communities around carrion.Implications for insect conservation: Our study highlights the diversity of beetles that can be found at carrion and their similar composition to the fauna found in other areas in the south-east of the Australian continent. Beetles may have reduced abundance at mass mortality sites which could affect their ability to contribute to carrion removal relative to smaller carrion quantities. Further research is required to quantify the role of other insects in carrion removal under a range of natural and mass mortality scenarios.

Characterization of Bacillus anthracis replication and persistence on environmental substrates associated with wildlife anthrax outbreaks.

Anthrax is a zoonosis caused by the environmentally maintained, spore-forming bacterium Bacillus anthracis, affecting humans, livestock, and wildlife nearly worldwide. Bacterial spores are ingested, inhaled, and may be mechanically transmitted by biting insects or injection as occurs during heroin-associated human cases. Herbivorous hoofstock are very susceptible to anthrax. When these hosts die of anthrax, a localized infectious zone (LIZ) forms in the area surrounding the carcass as it is scavenged and decomposes, where viable populations of vegetative B. anthracis and spores contaminate the environment. In many settings, necrophagous flies contaminate the outer carcass, surrounding soils, and vegetation with viable pathogen while scavenging. Field observations in Texas have confirmed this process and identified primary browse species (e.g., persimmon) are contaminated. However, there are limited data available on B. anthracis survival on environmental substrates immediately following host death at a LIZ. Toward this, we simulated fly contamination by inoculating live-attenuated, fully virulent laboratory-adapted, and fully virulent wild B. anthracis strains on untreated leaves and rocks for 2, 5, and 7 days. At each time point after inoculation, the number of vegetative cells and spores were determined. Sporulation rates were extracted from these different time points to enable comparison of sporulation speeds between B. anthracis strains with different natural histories. We found all B. anthracis strains used in this study could multiply for 2 or more days post inoculation and persist on leaves and rocks for at least seven days with variation by strain. We found differences in sporulation rates between laboratory-adapted strains and wild isolates, with the live-attenuated strain sporulating fastest, followed by the wild isolates, then laboratory-adapted virulent strains. Extrapolating our wild strain lab results to potential contamination, a single blow fly may contaminate leaves with up to 8.62 x 105 spores per day and a single carcass may host thousands of flies. Replication outside of the carcass and rapid sporulation confirms the LIZ extends beyond the carcass for several days after formation and supports the necrophagous fly transmission pathway for amplifying cases during an outbreak. We note caution must be taken when extrapolating replication and sporulation rates from live-attenuated and laboratory-adapted strains of B. anthracis.

Mass mortality events and declining obligate scavengers in the Anthropocene: Social feeders may be critical

A pervasive but understudied global change is occurring in the Anthropocene. Wildlife mass mortality events (MMEs) are increasing in frequency causing the abrupt entry of unusually large amounts of carrion into ecosystems, while most vertebrate obligate scavenger species are declining. We hypothesized that behavioral plasticity could still allow obligate-vertebrate scavengers to maintain carrion recycling with increasing carrion biomass as a result of relaxed competition, and that consumption is likely to be driven by those species less behaviorally constrained. We designed an experiment by establishing plots with increasing carrion biomass. The lowest carrion biomass represented a normal level of carrion with a single carcass, with each subsequent level of carrion biomass roughly doubling until reaching a carrion density similar to a recent MME. We monitored behavior of two obligate scavenger species: a social feeder (i.e., black vulture, Coragyps atratus) and a relatively solitary feeder (i.e., turkey vulture, Cathartes aura). In support of our hypothesis, group size and number of individuals feeding increased at the highest carrion biomass level for the more social feeder, while the less social increased solely the number of individuals feeding. Likewise, activity pattern overlap between the species increased with carrion biomass likely because both spent more of the day consuming larger carrion inputs. The effects of these behavioral changes resulted in an increase in estimated consumption with carrion biomass, which was primarily driven by the more social species. Our results indicate that vulture behavioral plasticity may be critical to maintain carrion recycling services in the Anthropocene.

Comparison of the current abattoir surveillance system for detection of paratuberculosis in Australian sheep with quantitative PCR tissue strategies using simulation modelling

Abattoir surveillance for Johne’s disease monitoring in Australia has provided valuable feedback to producers about their flock’s disease status since its commencement in 1999. The current surveillance system relies on the identification of gross lesions in sheep carcases at an abattoir, followed by sampling and histopathology testing. This manual inspection system has not been adapted to meet the changing disease situation, as infection prevalence levels have declined over time due to vaccination. This simulation study compares the current system with two alternative approaches utilising a validated quantitative (q)PCR method for the detection of Mycobacterium avium subsp. paratuberculosis in tissues, with random systematic sampling either alone or in conjunction with sampling of a single carcass presenting gross lesions. Consigned sheep were randomly simulated as either infected or uninfected according to defined prevalence levels of infection, with varying histopathological lesion severity and the presence or absence of gross lesions. These sheep were then allocated into multiple ‘lines’ (group of sheep slaughtered together) within each consignment, with each line subjected to testing with the three sampling strategies for the estimation of line and flock (consignment) sensitivity. The line sensitivity described the proportion of infected lines that tested positive, whereas the flock sensitivity was the proportion of consignments from the simulated infected flocks that had one or more lines test positive for paratuberculosis infection. The tissue qPCR strategy with gross lesion detection achieved marginally higher line sensitivity than the current abattoir surveillance strategy. The simulation of unvaccinated infected flocks with low to moderate prevalence levels demonstrated similar flock sensitivity for all three sampling models. However, the current strategy had very low line sensitivity for the simulated vaccinated infected flocks when the infection prevalence level was <2%. There were substantial differences in flock sensitivity between the two tissue qPCR approaches and the current abattoir surveillance strategy for vaccinated infected flocks, whereas, only marginal differences in flock sensitivity were evident between the two tissue qPCR models. Our results demonstrate that the current strategy is not effective at identifying infected animals at very low infection prevalence levels. The tissue qPCR approach investigated in this study is better as it removes the reliance on meat inspectors to identify gross lesions and can also assist in identifying flocks that have subclinical infected sheep not displaying gross lesions. Therefore, the sheep industry may benefit from incorporating tissue qPCR for Johne's disease surveillance, however the logistics and costs of conducting this type of testing would need to be considered prior to implementing any changes.

Maternity uncertainty in cobreeding beetles: females lay more and larger eggs and provide less care

Abstract Cobreeding, which occurs when multiple females breed together, is likely to be associated with uncertainty over maternity of offspring in a joint brood, preventing females from directing resources towards their own offspring. Cobreeding females may respond to such uncertainty by shifting their investment towards the stages of offspring development when they are certain of maternity and away from those stages where uncertainty is greater. Here we examined how uncertainty of maternity influences investment decisions of cobreeding females by comparing cobreeding females and females breeding alone in the burying beetle, Nicrophorus vespilloides. In this species, females sometimes breed together on a single carcass but females cannot recognize their own offspring. We found that cobreeding females shifted investment towards the egg stage of offspring development by laying more and larger eggs than females breeding alone. Furthermore, cobreeding females reduced their investment to post-hatching care of larvae by spending less time providing care than females breeding alone. We show that females respond to the presence of another female by shifting allocation towards egg laying and away from post-hatching care, thereby directing resources to their own offspring. Our results demonstrate that responses to parentage uncertainty are not restricted to males, but that, unlike males, females respond by shifting their investment to different components of reproduction within a single breeding attempt. Such flexibility may allow females to cope with maternity uncertainly as well as a variety of other social or physical challenges.

Post-mortem indices of black-and-white breed

The research findings showed that the carcass weight of cows after fattening made 325.20±18.23 kg, and in cows that were not on feed it was 251.34±10.23, which was 73.86 kg less compared to cows sold after fattening. The carcass yield made 46.70 and 44.26±0.61% or 2.44% higher, respectively. The carcass weight of first-calf heifers after fattening made 193.78±2.81 kg, and in first-calf heifers that were not on feed it was 171.0±2.98 kg, which was 22.78 kg less compared to first-calf heifers after fattening. The carcass yield made 40.80 and 38.50±0.46% or 2.30% higher, respectively. The carcass weight of young cattle after fattening made 183.2±4.49 kg, and in young cattle that was not feed it was 136.93±5.69 kg, which was 46.27 kg less compared to young cattle sold after fattening. The carcass yield made 45.70±0.63 and 38.70±0.70% or 7.00% higher, respectively. The carcass yield in all age-sex groups corresponds to the indices for black-and-white breed. Not a single carcass of slaughtered animals is qualified as “super”, “prima”, “extra” and “excellent” category because they do not meet the requirements of GOST according to the carcass weight. The carcass of slaughtered animals is mainly qualified as “good”, “satisfactory” and “low” category. The results of the slaughtering of the researched animals by age-sex groups are as follows. The first-calf heifers after fattening belong to “good” category; because their carcass weight is in the range of 187.3-204.1, class G, subclass 1. The first-calf heifers without fattening correspond mainly to “satisfactory” category, because their carcass weight is in the range of 163.5-183.6 kg, class D and subclass 2. The heifers between the age of 8 month and 3 years old after fattening are mainly qualified as “excellent” category, because their carcass weight is in the range of 166.8-193.9 kg, class G, subclass 1. The heifers between the age of 8 month and 3 years old without fattening are mainly qualified as “low” category, because their carcass weight is in the range of 1128.1-153.5 kg, class D and subclass 2.

Improving antimicrobial residue surveillance in finishing pigs by risk-based sampling designs

EU Member States are obliged by legislation to implement residue surveillance programs to detect illegal use or misuse of veterinary medicines in food producing animals and investigate the reasons for residue violations. According to EU legislation, these programs should be (partly) risk-based, meaning targeted towards groups of animals, where the probability of finding residues is the highest. There is however no default surveillance procedure describing the most efficient way to do so. In this study, a quantitative analysis was conducted to quantify the effectiveness of detecting antimicrobial residues in finishing pigs via risk-based sampling of carcasses. A stochastic scenario tree analysis was applied to estimate the sensitivity of random and risk-based sampling strategies to detect a contaminated carcass. In these models, the probability was calculated that a single carcass will yield a positive outcome when subjected to the testing protocol laid down in the design, given that contamination with antimicrobial residues is prevalent in the herd of origin at the level of the design prevalence. Two design prevalences were used: 0.01% (the assumed true prevalence of residue-positive carcasses) and 0.22% (the prevalence that can be detected using the sample size laid down in EU legislation). In the random design, it was assumed that the carcasses examined for presence of antimicrobial residues were selected randomly from all finishing pigs slaughtered in a year. In the risk-based design, two risk factors were taken into account. First, a high prevalence of chronic pleuritis and pneumonia in the herd of origin was assessed. Secondly, the route of administration of antimicrobials (oral/parenteral) via visual inspection of skin lesions indicative of injectables was used as an additional risk factor. Results showed that the probability of detecting a residue-positive carcass doubled when surveillance was targeted at pigs originating from herds with a high prevalence of chronic pleuritis and pneumonia (compared to random sampling), at similar costs of testing. Including administration route as an additional risk factor led to a negligible increase in sensitivity. Nevertheless, sensitivity values at unit level remained extremely low due to the very low prevalence of antimicrobial residues in pigs. In this study, risk-based alternatives to random sampling improved the cost-effectiveness of residue surveillance in slaughter pigs in the Netherlands, which could be used to enhance current programs and to increase awareness in food business operators.

Investigation on structural behavior of ring-stiffened composite offshore rubber hose under internal pressure

Ring-stiffened composite offshore rubber hose of single carcass is commonly used for offshore oil transfer. Common hose dimensions are length of 10.7 m and nominal diameter of 500 mm. The nominal burst pressure is 7.5 MPa, equal to five times rated working pressure of 1.5 MPa. The hose carcass is composite cylindrical tube made of rubber, reinforcing fiber cords and steel spiral stiffener that provides radial stiffness. In hose design, the burst pressure shall be determined to verify its pressure bearing capacity. In this paper, a nonlinear finite element hose model is created with commercial software ABAQUS and validated to predict its structural behavior under internal pressure. The large deformations, interactions between components and nonlinear material properties of hyperelastic rubber and fibers are considered. Stresses of stiffener, radial and axial deformation and load in reinforcement plies are obtained. A bulging phenomenon amid two stiffeners is found, which indicates the confine effect of stiffeners. Failure pressure is jointly determined by the strength limit of polymer cords and steel stiffener. The influence of different fibers and rubbers on hose pressure-deformation response are compared. The results demonstrate good accordance with requirement of specification. The finite element model can predict hose failure pressure and provide guidance for reliable hose design in practice.

FwJj70 – A potential Early Stone Age single carcass butchery locality preserved in a fragmentary surface assemblage

The Okote Member (1.39–1.53 million-years-ago) of the Koobi Fora Formation preserves a rich and well-resolved lithic archaeological record, but comparatively little is known about the paleoecology of stone tool use during hominins' carnivorous foraging behavior. Archaeological butchery traces are typically found in fragmentary assemblages with well-preserved cortical surfaces that include multiple butchered individuals and carcass parts, but conclusions about butchery behavior, including skeletal element profiles and element and individual estimates may be impacted by specimen identifiability and differential preservation during palimpsest assemblage formation. Here we present an analysis of a fragmentary surface assemblage of fossil bone, designated FwJj70, that includes butchered and tooth-marked specimens and fragments of additional mammal carcasses to explore the archaeological visibility of carcass consumption at the lower boundaries of data quality – in particular, imprecise specimen identifiability and poor assemblage preservation. FwJj70 includes a similar composition of mammalian families and size classes in comparison with the fauna recorded along 400 m of the same stratigraphic horizon but possesses less weathered specimens with fewer post-fossilization and dry fractures, suggesting that bone specimens were rapidly buried. Excavation in search of an in situ origin of the surface assemblage recovered three specimens, but did not reveal a clear archaeological horizon. FwJj70 includes 40 identifiable specimens from at least 21 elements and six mammalian individuals. Eight specimens from a minimum of four elements and a single individual preserve evidence of hominin butchery and may come from a single size-three mammal carcass. However, poor specimen identifiability and ex situ context lead to a coarse estimate of the true number of butchered animals in the assemblage, blurring the distinction between a single carcass butchery episode and consumption of multiple animals, and masking the activity of carnivores. Despite this equifinality, the anatomical location of butchery marks at FwJj70 provides evidence of discrete aspects of hominins' tool-assisted carnivorous foraging niche, including early access to limb flesh packages, bone marrow consumption, and competition with other carnivorous consumers.

Odeurs indésirables de la viande de porcs mâles non castrés : problèmes et solutions potentielles

La présence d’odeurs indésirables dans la viande de porcs mâles entiers est principalement liée à l’accumulation d’androsténone et de scatol. L’androsténone est synthétisée par les testicules et le scatol par les bactéries du colon à partir du tryptophane. Leur teneur dans le tissu adipeux résulte du bilan entre leur synthèse, leur élimination et leur réabsorption. Le principal levier d’action pour réduire la teneur en androsténone est la sélection génétique. Pour le scatol, les principaux leviers d’action concernent la conduite d’élevage : propreté des cases, gestion de l’environnement microclimatique et conduite alimentaire, notamment. La mixité des groupes et l’instabilité sociale ont peu d’impact sur les teneurs en composés odorants, mais sont importantes à contrôler pour réduire les risques de bagarres et de lésion. Même en réduisant fortement la teneur en composés odorants, il ne sera pas possible d’obtenir des niveaux indétectables sur toutes les carcasses. Une stratégie d’utilisation des carcasses odorantes de porcs mâles entiers doit être définie. Elle implique de comprendre les facteurs de rejet des viandes odorantes par les consommateurs. La perception d’odeurs sexuelles dépend de facteurs liés à l’animal, au type de produit, au mode de préparation/consommation et au consommateur lui-même. De plus, les deux molécules odorantes semblent interagir. La prise en compte des différents cas de figure peut être envisagée par une approche de modélisation, avec en préalable la mise en œuvre d'une détection des odeurs sur la chaine d’abattage. Or actuellement, seule la détection par le nez humain est opérationnelle au niveau des chaines d’abattage et des méthodes instrumentales restent à développer.

Probability of Escherichia coli contamination spread in ground beef production.

Human illness due to contamination of food by pathogenic strains of Escherichia coli is a serious public health concern and can cause significant economic losses in the food industry. Recent outbreaks of such illness sourced from ground beef production motivates the work in this paper. Most ground beef is produced in large facilities where many carcasses are butchered and various pieces of them are ground together in sequential batches. Assuming that the source of contamination is a single carcass and that downstream from the production facility ground beef from a particular batch has been identified as contaminated by E. coli, the probability that previous and subsequent batches are also contaminated is modelled. This model may help the beef industry to identify the likelihood of contamination in other batches and potentially save money by not needing to cook or recall unaffected batches of ground beef.

A clear and present danger: impacts of poisoning on a vulture population and the effect of poison response activities

AbstractVultures in Africa are being poisoned deliberately by poachers to prevent the birds alerting authorities to the poachers’ illegal activities, or for harvesting and sale of body parts for use in witchcraft. Hundreds of vultures can be killed at a single poisoned elephant Loxodonta africana carcass, and although field staff trained in poison response activities can limit the damage, mortalities remain numerous. We used the population viability analysis programme VORTEX to simulate seven 100-year-long scenarios investigating various rates of poisoning mortalities and the remedial effects of poison response activities on a population of Critically Endangered white-backed vultures Gyps africanus breeding in Kruger National Park, South Africa. In six scenarios the population declined (λ &lt; 1); in three scenarios the population remained extant over the 100-year simulations but declined by 60–90% from a starting size of 2,400 individuals. In two scenarios one poisoned elephant carcass left untreated and causing the greatest number of vulture deaths was modelled as a catastrophic event with a 50% probability of annual occurrence, which resulted in a 100% probability of population extinction, with a mean time to extinction of 55–62 years. Effective poison response activities were modelled as a 70% reduction of mortality at each poisoned elephant carcass and resulted in population persistence after 100 years but with a c. 90% reduction in size (final n = 205). We highlight that although poison response activities will not prevent poisoning from occurring, they form an essential part of wider conservation actions designed to prevent local extinctions of vultures or other vulnerable species.

Bacterial Genomics Reveal the Complex Epidemiology of an Emerging Pathogen in Arctic and Boreal Ungulates.

Northern ecosystems are currently experiencing unprecedented ecological change, largely driven by a rapidly changing climate. Pathogen range expansion, and emergence and altered patterns of infectious disease, are increasingly reported in wildlife at high latitudes. Understanding the causes and consequences of shifting pathogen diversity and host-pathogen interactions in these ecosystems is important for wildlife conservation, and for indigenous populations that depend on wildlife. Among the key questions are whether disease events are associated with endemic or recently introduced pathogens, and whether emerging strains are spreading throughout the region. In this study, we used a phylogenomic approach to address these questions of pathogen endemicity and spread for Erysipelothrix rhusiopathiae, an opportunistic multi-host bacterial pathogen associated with recent mortalities in arctic and boreal ungulate populations in North America. We isolated E. rhusiopathiae from carcasses associated with large-scale die-offs of muskoxen in the Canadian Arctic Archipelago, and from contemporaneous mortality events and/or population declines among muskoxen in northwestern Alaska and caribou and moose in western Canada. Bacterial genomic diversity differed markedly among these locations; minimal divergence was present among isolates from muskoxen in the Canadian Arctic, while in caribou and moose populations, strains from highly divergent clades were isolated from the same location, or even from within a single carcass. These results indicate that mortalities among northern ungulates are not associated with a single emerging strain of E. rhusiopathiae, and that alternate hypotheses need to be explored. Our study illustrates the value and limitations of bacterial genomic data for discriminating between ecological hypotheses of disease emergence, and highlights the importance of studying emerging pathogens within the broader context of environmental and host factors.

Carcass Age and Reproductive Costs forNicrophorus orbicollis(Coleoptera: Silphidae)

The life history costs of living in microbially dense environments can be high. To assess the importance of these costs for natural selection, it is necessary to know how costs vary with environmental conditions. Adult burying beetles prepare vertebrate carcasses of varying age and states of deterioration as a resource for their young. In the present study, Nicrophorus orbicollis Say females were presented with either fresh or aged (80 h) large carcasses (30-39 g) to examine effects on their lifetime reproductive success (four reproductive attempts) and survival. Reproductive success and survival were also measured for female offspring that developed on fresh and aged carcasses. Carcass age had no measurable effect on lifetime reproductive output or life span of either parents or their adult offspring. In a separate experiment using medium-sized carcasses (22-24 g), the reproductive performance of females in a single reproductive attempt was negatively affected by carcass age (13.9% less brood mass). The results suggest that the costs of using a single older carcass are relatively minor when measured over a lifetime. Alternative costs of using older carcasses and explanations for the complex antimicrobial traits of burying beetles are discussed.

CFD modeling of industrial cooling of large beef carcasses

A computational fluid dynamics (CFD) model was developed to predict the changes in temperature and pH distribution of a beef carcass during chilling. The model was solved using the 3D geometry of the carcass side obtained by digital scanning and including post-mortem reaction kinetics. Carcass temperatures at various depths and sections were measured during a chilling experiment of a single carcass in commercial chiller conditions for model validation. The temperature predictions agreed with the measured temperature profiles at different positions inside the carcass, with excellent prediction in deep positions of the hindquarter as compared to near surface positions. The simulations unveiled large difference in cooling rates and pH evolution between different parts of the carcass that could lead to differences in meat quality by heat shortening. The model can be used to study the effect of relevant cooling parameters on the rate and uniformity of cooling and meat quality.

Identification and characterization of SREBF2 expression and its association with chicken carcass traits.

The sterol regulatory element-binding transcription factor 2 gene (SREBF2) plays an important role in regulating lipid homeostasis. To reveal the genetic factors that underlie carcass fat deposition in chickens, we cloned the coding DNA sequence of chicken SREBF2, investigated SREBF2 mRNA expression levels in various tissues, detected single nucleotide polymorphisms (SNPs) in the exon regions of the gene, and conducted association analyses between single markers/haplotypes and carcass traits. The entire 2859-bp cDNA sequence of chicken SREBF2 that encoded 952 amino acids was obtained and characterized. SREBF2 mRNA was highly expressed in the uropygial gland, followed by the liver, breast muscle, and leg muscle. Ten SNPs were detected, and four (g.49363077T>A, g.49357503C>T, g.49355533G>A, and g.49354641G>A) were novel. When analyzing the associations between the single mutations and carcass traits, significant differences were found in three SNPs and g.49357915G>A was highly significantly associated with most carcass traits, except for abdominal fat weight and sebum thickness. In addition, haplotype combinations that were constructed using the SREBF2 SNPs were associated with breast muscle weight. Chickens with the combined genotype H21H21 had the highest live weight, carcass weight, eviscerated weight, and semi-eviscerated weight values. To the best of our knowledge, this is the first study conducted on chicken SREBF2 polymorphisms, which are predictive of the genetics that underlie the economic performance of chickens.

Associations between single nucleotide polymorphisms and carcass traits in Nellore cattle using high-density panels.

The objective of this study was to evaluate associations between single nucleotide polymorphism (SNP) markers and carcass traits measured postmortem in Nellore cattle. Records of loin eye area (LEA) and backfat thickness (BF) from 740 males and records of hot carcass weight (HCW) from 726 males were analyzed. All of the animals were genotyped using the BovineHD BeadChip. Association analyses were performed by the restricted maximum likelihood method that considered one SNP at a time. Significant SNPs were identified on chromosomes 2 and 6 for LEA and on chromosomes 7, 1, and 2 for BF. For HCW, associations with SNPs were found on chromosomes 13, 14, and 28, in addition to genome regions that were directly related to this trait, such as the EFCAB8 and VSTM2L genes, and to bone development (RHOU). Some SNPs were located in very close proximity to genes involved in basal metabolism (BLCAP, NNAT, CTNNBL1, TGM2, and LOC100296770) and the immune system (BPI).