Supplementation strategy and grazing management can strongly influence dairy cow feeding behaviour, herbage intake, milk production and methane emissions. Two studies were conducted to investigate (1) the level of supplementation with partial mixed rations (PMR) and (2) the timing of maize silage feeding (morning vs. evening) for cows that have access to pasture either only during the day or day and night. A dataset was built that includes all individual cow measurements from both studies. It consists of 18 Microsoft® Excel files that correspond to several scales of information. The main file, “GrASTech_04_CowMeasurements”, contains individual weekly measurements of milk production and composition, body weight, supplement and herbage dry matter intake measured using the n-alkane method and grazing behaviour measured using Lifecorder Plus, for a total of 168 cow × week datapoints. Five Excel files provide supplementary information at larger scales: periods, experimental treatments, feeds offered and their chemical composition, pasture characteristics and grazing management, and cow characteristics. The remaining 12 Excel files provide information at the daily scale on weather (1 file), methane concentrations and emissions (1 file), the grazing schedule (1 file) and grazing behaviour (9 files). The files related to grazing behaviour include the daily pattern of grazing time every 2 min as determined by Lifecorder Plus, as well as the daily pattern of grazing time, rumination, overactivity, other activity, rest and standing every 5 min as determined by Feed'Live. This dataset can be used to better understand and investigate relations among and the influence of animal characteristics, grazing management, the supplementation strategy and weather conditions on daily herbage intake, grazing behaviour, milk production and methane emissions at a weekly scale. The detailed information on feeding and grazing behaviour can also be used to study between-cow and between-day variability in daily cow activities.

The increasing human population and demand for animal food products raise the issue of impacts of animal systems on food security caused by their use of human-edible feed and/or tillable land. The utility of replacing animal systems with potential food-crop systems needs to be assessed but is associated with many uncertainties. Some metrics analyse the contribution of current animal systems to food security, especially the dimension of food availability. These methods address feed conversion efficiency (i.e. total (‘gross’) or human-edible (‘net’)) or the efficiency of agricultural land use (i.e. total, permanent grassland, and tillable land) but never both simultaneously. The purpose of this study was to develop a new metric—‘net productivity’—to represent the performances of current animal systems more accurately by considering both the use of human-edible feed and agricultural land. Through a protein assessment, we analysed the ability of the existing and the new metrics to assess the performances of 111 dairy farms in Wallonia (Belgium). We found that net productivity was positively correlated with both metrics of feed conversion efficiency and negatively correlated with the three metrics of land use. To analyse the influence of farm characteristics, we grouped the farms into four clusters using k -means clustering based on these metrics of contribution to food security and then performed redundancy analysis to select the most influential farm characteristics aiming to highlight contrasted farm strategies. The highest net productivity was reached by an ‘intensive and net efficient’ farm strategy, which had intensive grass-based management, high milk production per cow, appropriate use of concentrates, and well-managed dairy followers (i.e. replacement heifers and calves). The newly developed metric of net productivity can be useful to quantify the contribution of dairy systems to food security by considering both the use of human-edible protein and agricultural land simultaneously.

Among ruminants, dairy cows and young cattle are the main consumers of soybean meal, which is mostly imported. The use of rapeseed meal is the first solution to replace soybean meal in cattle breeding and improve national protein autonomy, but it does not improve autonomy at the farm level. Whole plant corn fodder is widely used to feed cattle with high production potential, but it is low in protein. The addition of a protein-rich forage instead of part of the whole-plant corn forage is a first step to gain protein autonomy. However, it is possible to design rations that improve the efficiency of the protein concentrate provided and to introduce protein crops into the rations of cows and calves. Aiming for rations providing about 90 g DPI/kg DM in the INRA 2018 feeding system seems to be a good compromise to get good value from the proteins provided by the ration. Replacing soybean meal with raw pea, faba bean and lupin seeds is possible. With rations that include a high proportion of corn silage (over 65 %) and high production levels, soybean meal can only be partially replaced. For dairy cows and calves, 1.5 to 2.6 kg of protein crops are needed to replace 1 kg of soybean meal. However, the total nitrogen content of these seeds is much lower than that of soybean meal and they are characterized by a high nitrogen degradability, which limits their DPI value (digestible proteins in the intestine). Seed treatment by toasting or extrusion processes is an alternative that is receiving renewed interest to remedy this high nitrogen degradability of protein crops. Recent trials have shown an improvement in the PDI value of the seeds with these processes. However, this did not improve the performance of the animals, which for the moment limits their interest in gaining protein autonomy.

Through the importance of the surface area used (more than half of the French agricultural area) and the importation of part of protein-rich feedstuffs, ruminant feed is at the heart of the technical, economic, environmental and societal challenges facing livestock farming. Climate change is already affecting forage calendars and available feed resources. Faced with these challenges, many levers exist either to adapt existing resources or to develop new ones. They are based on the adaptation of grasslands (introduction of species resilient to climate change) and their management, the use of cereal-legume intercrops, summer catch crops, C4 photosynthetic plants and the development of agroforestry. The diver-sification of cropping systems made necessary by the reduction of synthetic fertilizers and pesticides should provide new resources for livestock farming (forage and seed legumes, intercropping). New technological processes, such as the bio-refining of fodder, offer prospects, as does better use of the co-products of the agri-food industry. The use of insects as a source of protein is not yet authorized for ruminant farming in the EU. The use of algae raises the question of the volumes needed to feed ruminants, but they offer prospects as feed additives to reduce enteric methane emissions. Characterizing these new feed resources raises many research and development questions. This requires a sufficient amount of new data obtained from in vivo reference feed evaluation methods to be able to strengthen the databases used for feed value tables and prediction tools.

À travers l’importance des surfaces valorisées (plus de la moitié de la surface agricole française) et l’importation d’une partie des matières premières riches en protéines, l’alimentation des ruminants est au cœur des enjeux techniques, économiques, environnementaux et sociétaux des élevages. Le changement climatique affecte déjà les calendriers fourragers et les ressources alimentaires disponibles. Face à ces enjeux, de nombreux leviers existent soit pour adapter les ressources existantes soit pour développer de nouvelles ressources. Ils reposent notamment sur l’adaptation des prairies (introduction d’espèces résilientes au changement climatique) et de leur gestion, l’utilisation des mélanges céréales-protéagineux, des dérobées estivales, des plantes à photosynthèse en C4 et le développement de l’agroforesterie. La diversification des systèmes de cultures rendue nécessaire par la réduction des engrais et pesticides de synthèse devrait fournir de nouvelles ressources à l’élevage (légumineuses fourragères et à graines, intercultures). De nouveaux procédés technologiques, comme le bio-raffinage offrent des perspectives comme une meilleure valorisation des coproduits des industries agroalimentaires. L’utilisation des insectes comme source protéique n’est pas encore autorisée en élevage de ruminants dans l’UE. Celle des algues pose la question des volumes nécessaires pour alimenter des ruminants, mais elles offrent des perspectives en tant qu’additifs alimentaires pour réduire les émissions de méthane entérique. Caractériser ces nouvelles ressources alimentaires pose de nombreuses questions de recherche et de développement. Cela nécessite de collecter un nombre suffisant de nouvelles données par les méthodes de référence d’évaluation des aliments in vivo pour conforter les bases de données, construire les tables de valeur alimentaire et développer les outils de prévision.

Modern systems of animal production are facing increasing challenges on issues such as animal welfare, product quality, and environmental impact. Ruminants in particular are often regarded as being inefficient with respect to feed conversion for both protein and energy. Efficiency is defined as the ratio between resources and production; when applied to dairy production systems, it corresponds to the total amount of feed (kg of dry matter of roughages and concentrates) consumed per kg of milk and meat produced. This ratio underlines the biological ability of dairy cows, ewes, and goats to convert feed into products that are edible by humans while maintaining other physiological functions. Feeds consumed by animals can be “human-edible”, i.e. directly usable for human nutrition (cereals, legumes, maize silage), or not (grasslands, wild grass areas). Calculations of livestock efficiency are strongly influenced by whether or not they consider, and distinguish between, the consumption of human-edible or -inedible plant resources (roughages and concentrates) as well as the production of edible and/or inedible animal products (e.g., milk, meat, wool, leather). An improved understanding of the inedible fraction of both energy and protein in animal feed will be invaluable in analyses of feed-food competition, especially in ruminants. In this study, we investigated the feed conversion efficiency (FCE) of dairy ruminant systems in France (cow, goat, ewe) with respect to both energy and protein. We hypothesized that FCE would be influenced by the composition of the diet and its grass content, as well as, by animal type. Data from a French database (Diapason) provided information on land, labor, herds, and production from 2012 to 2016 for 274 dairy goat farms, 108 dairy ewe farms, and 498 dairy cow farms. These herds consumed feeds that were human-edible (cereals, legumes, maize silage) as well as -inedible (grasslands, wild grass areas). We estimated that French dairy systems are, on average, net consumers of energy and net producers of protein, with higher efficiencies for grass-based systems compared to maize-based systems. At the national scale, average net protein efficiencies were 1.16, 1.12, and 1.88 for ewes, goats, and cows, respectively. These results on the net FCE in dairy systems will promote a more objective quantification of their contribution to food security, which should be taken into account in assessments of feed-food competition and its impact on human nutrition. When combined with other factors such as greenhouse gas emissions and land and resource use, such considerations will help to inform discussions of the future of livestock production.

The laser methane detector (LMD), is a proprietary hand-held open path laser measuring device. Its measurements are based on infrared absorption spectroscopy using a semiconductor laser as a collimated excitation source. In the current study, LMD measurements were carried out in two experiments using 20 and 71 lactating dairy cows in Spain and Scotland, respectively. The study aimed at testing four assumptions that may impact on the reliability and repeatability of the LMD measurements of ruminants. The study has verified that there is no difference in enteric methane measurements taken from a distance of 3 m than from those taken at a distance of 2 m; there was no effect to the measurements when the measurement angle was adjusted from 90° to 45°; that the presence of an adjacent animal had no effect on the methane measurements; and that measurements lasting up to 240 s are more precise than those taken for a shorter duration. The results indicate that angle, proximity to other animals, and distance had no effects and that measurements need to last a minimum of 240 s to maintain precision.

L’élevage est souvent perçu comme inefficient pour produire des denrées alimentaires pour l’Homme car les animaux consomment davantage de végétaux qu’ils ne produisent de viande, de lait ou d’œufs. Le calcul de l’efficience nette de conversion des aliments en ne considérant dans le calcul que la part potentiellement consommable par l’Homme des aliments utilisés par les animaux permet de relativiser ce constat. En effet, une large part des aliments consommés par les animaux d’élevage (fourrages, coproduits…) n’est pas directement consommable par l’Homme. Appliqués à des systèmes d’élevage français, les calculs d’efficience nette montrent que toutes les productions animales (bovins laitiers et à viande, ovins à viande, porcins, poulets de chair, poules pondeuse) peuvent être producteurs nets de protéines à condition de maximiser la part des végétaux non valorisables en alimentation humaine dans les rations. Le calcul de l’efficience nette est très sensible à l’estimation de la part des aliments utilisés en alimentation animale qui peut être directement valorisée par l’Homme. Celle-ci varie fortement d’une matière première à l’autre selon les habitudes alimentaires et les technologies agroalimentaire qui peuvent évoluer dans le temps. Il est donc nécessaire d’analyser les résultats d’efficience nette à travers plusieurs scénarios de valorisation des matières premières végétales. De même le niveau de valorisation du cinquième quartier de la carcasse des animaux d’élevage pour l’alimentation humaine est très variable et influence sensiblement les résultats d’efficience nette. Enfin, la prise en compte du différentiel de qualité entre les protéines végétales permettrait d’affiner les calculs d’efficience protéique.

Depuis des décennies, les filières agroalimentaires génèrent des coproduits de première ou de deuxième transformation qui représentent en France un gisement important (12 millions de tonnes de matière sèche), dont plus de la moitié est issue des filières de la trituration (29 %), de la sucrerie (14 %) et de l'amidonnerie-féculerie (13 %). Les trois-quarts de ces ressources sont valorisés en alimentation animale, pour 80 % environ via les aliments composés et 20 % directement en élevage. De ce fait, les coproduits, que les réglementations européenne et française distinguent clairement de la catégorie « déchets », sont des matières premières de l'alimentation animale à part entière et doivent en respecter la réglementation. La disponibilité de ces coproduits peut fortement varier dans le temps avec une saisonnalité marquée pour certaines filières, ou dans l'espace selon la répartition des usines agroalimentaires sur le territoire et la superposition avec les zones d'élevage. Les procédés technologiques générateurs de ces coproduits peuvent différer d'une filière à l'autre. La nature et la composition chimique des coproduits dépendent du procédé mis œuvre qui peut évoluer dans le temps, mais également d'une usine à l'autre au sein d'une même agro-industrie. Leur bonne valorisation en alimentation animale est largement conditionnée par une connaissance précise de la qualité des différentes fractions organiques (parois végétales et protéines, notamment) ou minérales accumulées dans les coproduits, et de l'efficacité de leur utilisation qui peut varier fortement selon l'espèce animale destinataire (ruminants ou monogastriques) et selon les types de process appliqués. Un certain nombre de recommandations alimentaires et sanitaires doivent être appliquées pour garantir une utilisation optimale des coproduits par les animaux sans pénaliser leurs performances zootechniques. Ces coproduits présentent de ce fait une réelle valeur économique qu'il est possible de déterminer, même pour les ruminants, au moyen des outils de formulation à moindre coût par programmation linéaire couramment utilisés chez les monogastriques.

This study asks two main questions: a) how efficiently are plant proteins converted into daily proteins by livestock? and b) to what degree is there competition between systems for producing livestock feed and human food? We analysed the feeding systems used by French dairy farms (cow, goat, and sheep). We also examined the extent of competition between these feeding systems and food systems (i.e., competition = use of grain crops, pulse legumes, and silage maize; no competition = use of grasslands and rangelands). To this end, we evaluated gross and net feed-to-food protein conversion efficiencies (i.e., the ratio of human-edible proteins in dairy products to human-edible proteins in feed). We found that dairy systems make a net contribution to the dietary proteins consumed by the French population. The best results were obtained for grazing systems (overall mean net feed-to-food protein conversion efficiencies for the country: 1.16 for sheep, 1.12 for goats, and 1.88 for cows).

Livestock is often perceived as inefficient in producing food for humans because animals consume more plants than they produce meat, milk or eggs. The calculation of the net feed conversion efficiency by considering in the calculation only the potentially consumable part of the feed used by the animals makes it possible to relativize this observation. Indeed, a large part of the feed consumed by livestock (fodder, coproducts.) is not directly consumable by humans. Applied to French livestock systems, the net efficiency calculations show that all animal production (dairy and beef cattle, meat sheep, swine, broilers, layer hens) can be net producers of protein provided they maximize the use of non-edible feed for human in diets. The calculation of the net efficiency is very sensitive to the estimation of the part of the feed used in animals which can be directly valorized in human feeding. This part varies greatly from one feed to another depending on the food habits and agri-food technologies that can evolve over time. It is therefore necessary to analyze the results of net efficiency across several scenarios for valuing plant raw materials. Similarly, the level of valorisation of offals and byproducts of farm animals' carcasses for human consumption is highly variable and significantly influences the net efficiency results. Finally, taking into account the difference in quality between plant and animal proteins would make it possible to refine protein net efficiency calculations.

For decades, agro-food chains have been producing either first or second transformation byproducts, which represent in France a significant amount of resources (12 million tons of dry matter, Reseda 2007). These byproducts come mainly from the crushing sector (29 %), sugar refinery (14 %) and starch industry (13 %). Most of these resources (75 %) are used in animal feeding, including about 80 % via the compound feed industry and 20 % directly on the farms. Hence, agro-industrial by-products, which are clearly defined as non-waste products by French and European regulations, have become raw materials used in animal feed and must therefore comply with the regulations applicable to such products. The availability of these byproducts can vary considerably over time with a marked seasonality for certain sectors, as well as spatially according to the distribution of agro-food factories on the territory and the overlap with the animal production areas. The technological processes generating these byproducts can differ from one sector to another. Botanical and chemical composition of byproducts depend on the process implemented, which can evolve over time but also from one factory to another within the same agro-industry sector. Making the most of these byproducts in animal feeding is largely conditioned by the precise knowledge of the quality of the various organic (essentially cell walls and proteins) or mineral fractions accumulated in the byproducts, and of their utilization efficiency which can change strongly according to the animal species (ruminants vs monogastrics) and according to the types of processes applied. Some feeding recommendations and sanitary rules must be enforced to ensure an optimal utilization of byproducts by the animals without decreasing their performances. Therefore, these byproducts have a real economic value that can be determined, even for ruminants, using the low-cost linear programming formulation tools commonly used for monogastrics.

Direct measuring of enteric methane in breath of ruminants is becoming popular. Since the first peer-reviewed publication (Chagunda et al., 2009) showed the potential application of the proprietary Laser Methane Detector® (LMD) in ruminants, it has been shown to have strong relationship with traditional techniques such as respiration calorimetric chambers. For example, Chagunda et al, (2013) reported sensitivity and specificity for cows of 95.4% and 96.5%, and for sheep, sensitivity was 93.8% and specificity was 78.7%. However, there is no joined-up protocol covering all aspects, including, data collection, data extraction, data handling, and estimating methane volume from the measured concentration.