Abstracts - Process et Technologies

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.

The “GREEANIMO” project is a collaborative project between the University of Trakia in Bulgaria, INRAE in France and SRUC in Scotland. It concerns the breeding of herbivores according to the principles of agroecology and the quality of the meat. The project is structured according to four themes: “Improving meat quality”; “Increasing feed efficiency”; “Improving animal welfare”; “Design of sustainable ruminant breeding systems”. This session was open to all researchers from the GREEANIMO project but also to any researcher outside this project with scientific activity linked to one of these four themes.

The posters associated with this session displayed on the first two days of the joint EAAP/WAAP congress presented the latest scientific research on grading methods of beef, lamb and pork carcasses. Studies conducted on three continents show a craze in the meat industry for the use of innovative methods for predicting carcass quality. The results of these studies demonstrate a high potential for determining carcass characteristics to help the meat industry address issues such as predictions of carcass yield, composition and quality. The use of these prediction tools can guide the creation of quality assured supply chains and allow the industry to meet the needs of consumers at the center of attention.

This session presented at the recent combined EAAP/WAAP in Lyon described research on carcase grading to predict the true carcase value which is a product of eating quality of the cuts sold (determining price/kg) and lean meat yield determining the amount of meat sold. The results clearly show that it is possible to develop more sophisticated commercial grading systems underpinning true carcase value by using both traditional and new carcase grading technologies, importantly linked to the prediction of eating quality using untrained consumer based sensory testing. The new grading technologies based on X-ray and vision-based devices combined with rigorous statistical analysis, will lead to improved accuracies and precision. Even new traits like chemically measured intramuscular fat may replace human based visual grading of marbling. This will also facilitate carcase traits to be routinely used to underpin commercial genetic evaluation programmes.