Effect of flax-seed enriched concentrate supplementation in grazing Pramenka breed lamb's diet on omental fat fatty acids

10 páginas, 2 tablas.This research is aimed at determining the impact of supplementing extensively reared lambs with a limited amount of flax seed enriched-concentrate on the fatty acid profile of the lamb meat (omental fat depot). A total of 96 60-day old Pramenka breed lambs (23.85±3.98 kg live body weight; 60±10 days of age; 42 males and 54 females) raised on pasture with their dams were randomly divided in three experimental groups: control (CON) or extensive rearing group, which did not receive any supplementary feed; concentrate (CC) group, receiving 300 g of a conventional commercial concentrate feed per animal daily, and concentrate-flax seed (CC-FS) group, receiving 300 g/day of the concentrate supplemented with 5% of flax seed. After 60 days of experimental period, 10 lambs were selected (5 males and 5 females) from each group and slaughtered. Omental fat samples were taken and analyzed to determine their fatty acid profile. Significant (P>0.05) differences in the fatty acid profile between CON and CC groups were small. However, enrichment of the concentrate with 5% flax seed increased the percentages of PUFA and n-3 PUFA when compared to both CON and CC groups and thus slightly improved the nutritional characteristics of the omental fat. The effect of sex on the fatty acid profile was only observed for C20:4 n-6 and C20:5 n-3 (P < 0.05).Peer reviewe

Tester une innovation technique favorable aux abeilles mellifères par des approches participative et expérimentale – Projet InterAPI 1

La combinaison de la mortalité et de colonies non productrices en sortie d’hiver est responsable d’un taux de mortalité représentant près d’un tiers du cheptel. Nous nous sommes intéressés aux conditions environnementales des colonies d’abeilles mellifères à cette période cruciale de pré-hivernage. Une solution technique spécifique a été testée pour étudier l’influence de l’environnement sur la période d’hivernage des colonies. C’est grâce à une double approche d’accompagnement des acteurs et expérimentale s’appuyant sur une implication forte des agriculteurs et apiculteurs de la Beauce, que les partenaires du projet InterAPI mettent en évidence l’intérêt d’un aménagement du territoire qui intègre des cultures intermédiaires mellifères (CIM) favorables aux colonies. Ils identifient les espèces candidates et leurs caractéristiques grâce à deux outils d’aide à la gestion de cette interculture.The rates of honeybee colony winter losses remain very high describing mortalities and non-producing colonies after wintering represents nearly a third of the producing colonies. We were interested in environmental conditions of honeybee colonies at this crucial time. A technical solution has been tested and specifically to study environment influence on the wintering period of the colonies. Through a dual approach of co-construction and experimental, based on a strong involvement of farmers and beekeepers in Beauce region, partners of InterAPI project highlight the interest of a landscape management which includes melliferous catch crops. They identify candidate species and their characteristics using two tools helping the management of catch crops

An interdisciplinary approach to increase wheat within-field diversity and promote agro-ecosystem services

International audienceOne major challenge for increasing agriculture sustainability is to better mobilize crop genetic diversity, as prone by agroecology. A simple way to increase within-field diversity is to use cultivar mixtures, and this has been successfully applied to a few crops in the past. Despite numerous scientific papers documeting the value of cultivar mixtures in wheat and other cereals, especially to control diseases, their cultivation has remained marginal throughout the world. To understand the origin of this gap between scientific knowledge and agricultural practices, the French project Wheatamix explored the synergies mobilized by cultivar mixtures, their impact on various ecosystem services, and their potential to reinforce the sustainability, resilience, and multi-functionality of agriculture. It focused on the agro-ecological and socio-economic impacts of variety associations at different scales, from the plant level up to the wheat supply chain. The project aims at developing new blending and breeding methods to design performing mixtures.To understand how plant-to-plant interactions shape wheat mixtures performances, Wheatamix has set five objectives: 1) describe the variability of morphological and ecological traits in a panel of 57 varieties; 2) explore variability by blending 16 contrasted varieties from the panel into 72 mixtures, composed of 2, 4, and 8 components; 3) study the ecosystem services provided; 4) assess the technical and economic performances in farmer conditions; 5) evaluate the impact of cultivar mixtures on the wheat supply chain. To achieve these goals, this project has developed an interdisciplinary approach, mobilizing agronomy, ecology, economics, ecophysiology, epidemiology, genetics, and management sciences. The project brought together scientists from 10 labs, as well as agricultural advisers and farmers from 6 French counties. The project first described the functional diversity of 57 varieties, highlighting the effects of modern breeding on trait variability, that lowered variability of traits subject to direct selection, and impacted both plant architecture, physiological traits as nutrient absorption, but also trade-off between traits. Wheatamix then surveyed how variation in mixture diversity impacted wild communities. A first result highlighted the low abundance of macro-organisms in this experiment: no relationship was found between the number of varieties in a mixture and the diversity/abundance of earthworms, weeds, mycorrhizae, springtails, beetles, nematodes. However, a significant effect of mixture diversity on the abundance of some spiders, and on nitrifying bacteria, was observed. Coming to ecosystem services, disease regulation (rust and septoria) has been confirmed as the most strongly and positively affected by varietal associations, raising also the strong effects of architectural variability of the canopy (septoria). Diversity also contributed to higher predation rates on aphids. Lastly, soil nitrification and denitrification activities were significantly affected by mixture diversity on 4 surveyed sites, contributing to a shift in plant nutrition and positive effect of greenhouse gas emission.Co-design of variety mixtures was carried out with farmers, technical advisers, and scientists. For three years, 30 farmers in the Paris basin proposed varietal blends and measured their performance on their farms. This exchange first highlighted that the first goals for farmers was to i) secure their production ii) simplify plot management. Then co-design workshops allowed to propose assembly rules and design mixtures, resulting in a wide diversity of sown mixtures. Field trials revealed that in more than 70% of the cases, the mixture had a higher yield than the mean of its components. This work highlighted farmers needs and resulted in a Multicriteria Evaluation Tool, helping farmers and advisers to design mixtures. The survey of the wheat supply chain finally highlighted the need for a concerted innovation among the various actors. Finally, Wheatamix also developed new statistical method to infer mixing ability, allowing both to blend the best mixers, and also to propose new breeding methods.Coupling various disciplines and approaches, such as ecophysiological modeling of plant competition (FSPM WALTer), field and controlled experiments, theoretical framework in ecology (sampling vs complementarity effects, functional traits and tradeoff), and mixture co-design and surveys with stakeholders, Wheatamix has allowed to understand the interest of cultivar mixtures for farmers. Wheat cultivar mixtures are experiencing an exponential growth: they only represented 2% of bread wheat sown in 2010, and are presently at 8%, raking at the first position on the cultivar list. Wheatamix emphasizes the need for an interdisciplinary approach when addressing agroecological subjects, and illustrates the strong mutual benefices between agronomic and ecological sciences