Abstracts - Process et Technologies

Effect of the position of the gun on the brain damage caused by the captive bolt when stunning cattle
The impact of the position of the stun gun brain damage was studied in 19 cattle. The aim was to define a reliable method of damaging the Ascending Reticular Activating System (ARAS), which is strongly involved in consciousness. The positions tested were two positions located at the intersection of the diagonals between the animal's eye and the base of the opposite horn (Low position: Eye-hornB; High position: Eye-hornH) and two positions located in the middle of the line going from the top of the head to the line connecting the animal's two eyes (Low position: MedianB; High position: MedianH). When using the Eye-HornB position, the bolt usually passed below the brain. The Eye-HornB and Eye-HornH positions were influenced by the shape of the head. The MedianB and Eye-HornH positions resulted in damage to the ARAS in approximately half and three-quarters of the animals, respectively. The MedianH position produced satisfactory damage to the ARAS (within the target zone: 95% of the animals; at the limit of the target zone: 5% of the animals). The disadvantages of the latter position are a potentially too caudal position in some animals and the greater difficulty to use outer canthi of the eyes as a landmark. In conclusion, placing the gun 1 cm lower than the MedianH position, or about 2 to 3 cm higher than the Eye-hornH or MedianB positions, maximises the probability of damaging the ARAS, while limiting the risk of a too caudal position.

The concept of "rosé veal" is variously defined and underexplored in France. This type of production is well adapted for local breeds, as with Maraîchine. Slaughter performance data of rosé veal, extracted from a database comprising 119 calves observed between 2009 and 2023 at the INRAE experimental unit in Saint-Laurent-de-la-Prée, are presented. Biochemical and metabolic characteristics, as well as sensory and nutritional qualities of meat, were analyzed in a sample of 30 rosé veals (15 raised on maternal milk and grass (pasture and/or hay) (H diet) and 15 calves raised on maternal milk and supplemented with concentrates (C diet)) from 8 different farms. The calves have an average live weight of 219 kg, a carcass weight of 128 kg, and a meat weight of 90 kg. Carcass yields average 59%, and meat yields average 70%. Rosé veal meat is low in lipids (1.3g/100g of tissue) and exhibits a high proportion of polyunsaturated fatty acids (PUFA) close to 20%, with a PUFA n-6/n-3 ratio near 2. Calf supplementation has significant impacts on meat quality. The H diet influences carcass conformation, meat color, iron content (+24%), and tenderness. It increases the proportion of slow and oxydo-glycolytic fibers by 53%. Some levels of healthy fatty acids, vitamin B2 and health indicators also increased. They resulted in a twofold enrichment in endogenous or exogenous antioxidants and decreased levels of vitamins B3 and B6.

The growing demand for high-quality meat has led to the development of a grading system aimed at assessing and improving the quality of beef. In Europe, the mandatory grading system is the EUROP grid, which focuses on carcass conformation and fattening. In contrast, the grading system based on the Australian methodology (Meat Standards Australia - MSA) predicts sensory quality previously assessed by non-expert consumers. However, to develop a system based on this methodology, it is first necessary to have a good understanding of the terminology and the relevance of the evaluation criteria. In general, to facilitate communication among stakeholders, ontologies are used to describe knowledge domains. Some technical terminologies are ambiguous and vary between countries, especially for meat products, which requires careful information collection to create an accurate database. The objective of this work is to identify, describe, and compare definitions from existing ontologies and databases for technical terms used in the evaluation of beef carcasses according to the Australian methodology. Fifty-six terms have been identified and grouped into eight categories. Their definitions extracted from about twenty terminological tools have been compared. The benefits of these comparisons include a better understanding of the domain, the possibility of choosing more precise variables, and improvements in research and communication. However, there are still challenges in finding specific terms, and it is essential to standardize commercial language to facilitate collaboration among meat industry professionals. In summary, it is necessary to create a single source with robust definitions for MSA grading system terms, as well as a global ontology for beef meat quality to standardize the analyses. 

In a context where society is increasingly concerned about animal health and welfare issues, and where European regulations on the welfare of farm animals are being revised, the French Livestock Institute has been working on a number of projects in collaboration with various partners, including INRAE. This work, funded by INTERBEV Veaux and the French Ministry of Agriculture and Food Sovereignty, has focused in particular on identifying society's main expectations regarding the management of veal calves, and has highlighted the demand for animals to have outdoor access, a litter for bedding, natural light, roughage and group housing from an early age. Regarding animal housing, an overview of the main characteristics of calf housing facilities used in France was carried out. Trials have also been carried out to acquire references on the impact of different housing parameters on the health and well-being of calves (type of floor, group size, collective housing from the outset). Lastly, studies have been carried out on calf feed and health during rearing to assess the impact of different solid feed intakes on calf metabolism and behaviour, as well as the use of antibiotics in the sector between 2013 and 2020, followed by the introduction of tools for assessing biosecurity in rearing.

Airborne contamination of 8 beef abattoirs was characterized considering the air treatment systems in place. Based on the data acquired, thresholds in line with the bibliography were proposed for controlling total viable counts. For all abattoirs, airborne contamination by total viable counts and Enterobacteriaceae decreases from bleeding to carcass cooling. Total viable counts contamination levels in the “dirty” areas (bleeding, dehairing) differed little between slaughterhouses, exceeding 3.2 log CFU/m3. In “clean” areas (evisceration to cooling), contamination is more variable, illustrating the impact of the abattoir configuration on airborne contamination. Air treatment systems provide added value to control air flows in dehiding, trimming and weighing areas, compared with extractions alone. Nevertheless, these systems that control airflows are necessary but not sufficient. The physical separation of clean from dirty areas, the positions of extraction fans in the clean area to extract steam from carcasses and from equipment like steam vacuum, air leaks from the hair tripery to the clean area need to be considered. The use of F9 filters in air treatment systems to microbiologically treat outside air blown into the clean zone limits the variability of total flora contamination. But, like other configurations, it remains higher than that of the outside air (2.4 log CFU/m3). 

The « beef » sector is exploring how to guarantee delivering products to its clients with regular quality. However, the methods used to qualify beef tenderness are mainly invasive since they require sampling meat samples to be qualified. Therefore, tenderness is little or not at all evaluated by the sector. The objective of this study was to propose a non-invasive test, which ideally can be performed on a carcass and/or on-line, replacing the invasive tests used previously in laboratories (Warner-Bratzler shearing test, hardness test, penetration test, baking test). The new test is an indentation/relaxation/recovery test that leads to an estimation of tenderness indicators. The indentation method consists in the penetration of the meat with a hemispherical point, maintaining it in position then its rapid withdrawal, a phase associated with the return to equilibrium during which the movement at the meat surface is closely observed. A preliminary study on two pieces of meat with very different tenderness levels associates some of these indicators with data from compression tests (tensiometer), a device made available for this study by the Association for Development of the Meat Institute in Clermont-Ferrand (ADIV). In particular, after indentation, the gite round returns more quickly to its equilibrium state than the sirloin steak. The tendency that was observed on this “recovery” stage seems to be correlated with data obtained during penetrometry trials on similar samples. Statistical studies now need to be performed to validate the use of this tool for the industrial qualification of pieces of meat.