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A chemically defined medium without animal products for rabbit embryo vitrification
No full textInternational audienc
Caractérisation de la robustesse des vaches laitières
No full textCaractérisation de la robustesse des vaches laitières. Réseau Santé Animale Elevage Bio (SAEB
Fermented dairy product for a low-fat bakery product application: chemical and sensory analysis
No full textInternational audienceWhey was fermented using different lactic acid bacteria in order to obtain an ingredient as a substitute for butter in pastry products. Lactococcus lactis subsp. lactis biovar diacetylactis was selected based on its capacity to produce buttery flavours like diacetyl. Fermentation parameters such as temperature, aeration, citrate addition, and the duration of each fermentation step were selected in order to boost diacetyl production. Fermented whey was then added as an ingredient to white sandwich bread which did not initially contain any butter in the recipe. Sensory analysis brought to light that the buttery aroma was under the perception threshold in the bread containing the mixture even though the fermented whey contained diacetyl
L’Agriculture Biologique peut-elle se développer sans abandonner son principe d'écologie ? Le cas de la gestion des éléments minéraux fertilisants
No full textThe Ecology principle is at the core of organic farming. Regarding nutrient management, this principle implies that chemical fertiliser should be banned and be replaced by enhanced recycling (within and among farms) and biological nitrogen fixation by legumes. However, based on the survey of 63 organic farms in three French districts, we demonstrated that organic farming can be somehow, indirectly reliant on chemical fertiliser. Such reliance is due to two major factors. First, organic farms import a large share of their nutrients (23% of nitrogen and 73% of phosphorus entering organic farms, mostly as manure) from conventional farms. Second, organic farms can rely on nutrient accumulated in soils prior to the conversion: this legacy effect results in the 70% anthropogenic signature of the P in organic crop and animal products. These results suggest that organic farming development can conflict with the Ecology principle. However, this paper also demonstrates that some solutions exist to limit the indirect reliance on chemical fertilisers. In particular, the diversity of agricultural productions at the district scale is a strong leverage to increase nutrient recycling among organic farms.Le principe d'écologie, au fondement de l'Agriculture Biologique (AB), stipule que la gestion des éléments minéraux doit être fondée non pas sur le recours aux engrais de synthèse mais sur le recyclage des éléments au sein et entre fermes biologiques ainsi que sur les processus de fixation symbiotique par les légumineuses. Néanmoins, en se fondant sur le suivi de 63 fermes conduites en AB dans trois régions agricoles françaises, cet article montre que les exploitations biologiques ont recours indirectement à la fertilité héritée des engrais de synthèse. Ce recours se fait (i) soit par l'importation dans les fermes biologiques de produits élaborés par l'agriculture conventionnelle (sous forme d'engrais ou d'amendements organiques principalement), avec 23% de l'azote et 73% du phosphore entrants dans les fermes AB provenant de fermes conventionnelles, (ii) soit par l'utilisation des éléments minéraux accumulés dans les sols avant la conversion vers l'AB, avec environ 70% du phosphore des produits biologiques ayant de ce fait une origine anthropique. Ces éléments questionnent la tension existant entre développement de l'AB et respect du principe d'écologie. Des éléments de solution existent cependant, tel que le maintien de la diversité des productions agricoles à l'échelle du territoire, qui est susceptible de favoriser les processus de recyclage entre exploitations biologiques
Des produits biologiques ou locaux dans mon panier ? Forme d'arbitrage des consommateurs d'une grande zone urbaine
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Direct and correlated responses to selection in two lines of rabbits selected for feed efficiency under ad libitum and restricted feeding: II. Carcass and meat quality
No full textInternational audienceTo get insights into selection criteria for feed efficiency, 2 rabbit lines have been created: the ConsoResidual line was selected for residual feed intake (RFI) with ad libitum feeding and the ADGrestrict line was selected for ADG under restricted feeding. The aim of the present study was to evaluate the impact on carcass and meat quality of the genetic selections. This comparison was performed using 2 different feeding strategies corresponding to the selection design. Carcass and meat quality traits were recorded for the 3 lines (ConsoResidual, ADGrestrict, and an unselected control [generation 0 {G0}]) in the 2 feeding systems (ad libitum and restricted) for 163 animals. Concerning the line effect, the BW at 63 d old was higher for the ADGrestrict line compared with the G0 and ConsoResidual lines (P < 0.0001). There was no line effect on the gastrointestinal tract. The rabbits did not exhibit a different carcass yield but showed different carcass traits. Indeed, the ConsoResidual rabbits had a higher hind leg yield (P < 0.0001) but no difference in the meat-to-bone ratio of the hind leg. On the contrary, the ADGrestrict line had a higher proportion of forelegs plus thoracic cage (P = 0.03). We also found lower perirenal (P < 0.0001) and scapular fat yields (P < 0.0001) in ConsoResidual rabbits. The ADGrestrict line had an intermediate perirenal fat yield compared with the other 2 lines. The G0 line always exhibited higher fat yields. Concerning meat quality, the ConsoResidual rabbits showed a lower ultimate pH (P < 0.0001) and higher water loss (drip and cooking loss; P < 0.002) compared with the G0 and ADGrestrict rabbits. The feeding level had a strong effect on the gastrointestinal tract (P = 0.0004) and the carcass yield (P = 0.001). The latter was decreased in restricted rabbits. The effects of feeding strategy on meat quality were detrimental in the case of restricted feeding. Even if the ultimate pH was slightly higher in restricted rabbits (P = 0.0002), the carcass chilling loss (P = 0.0005) and the drip loss during 6 d (P < 0.0001) were higher. The selection on ADG with restricted access to feed seems to be less adversely correlated with carcass traits and meat quality traits but it leads to an increase in the live weight of the rabbits. Adversely, the selection on RFI, without affecting growth rate, would not modify age at slaughter because growth rate is not affected, but it might induce detrimental effects on meat quality
Shallow non-inversion tillage in organic farming maintains crop yields and increases soil C stocks: a meta-analysis
No full textInternational audienceAbstractReduced tillage is increasingly promoted to improve sustainability and productivity of agricultural systems. Nonetheless, adoption of reduced tillage by organic farmers has been slow due to concerns about nutrient supply, soil structure, and weeds that may limit yields. Here, we compiled the results from both published and unpublished research comparing deep or shallow inversion tillage, with various categories of reduced tillage under organic management. Shallow refers to less than 25 cm. We found that (1) division of reduced tillage practices into different classes with varying degrees of intensity allowed us to assess the trade-offs between reductions in tillage intensity, crop yields, weed incidence, and soil C stocks. (2) Reducing tillage intensity in organic systems reduced crop yields by an average of 7.6 % relative to deep inversion tillage with no significant reduction in yield relative to shallow inversion tillage. (3) Among the different classes of reduced tillage practice, shallow non-inversion tillage resulted in non-significant reductions in yield relative to deep inversion; whereas deep non-inversion tillage resulted in the largest yield reduction, of 11.6 %. (4) Using inversion tillage to only a shallow depth resulted in minimal reductions in yield, of 5.5 %, but significantly higher soil C stocks and better weed control. This finding suggests that this is a good option for organic farmers wanting to improve soil quality while minimizing impacts on yields. (5) Weeds were consistently higher, by about 50 %, when tillage intensity was reduced, although this did not always result in reduced yields
A panel of embryonic stem cell lines reveals the variety and dynamic of pluripotent states in rabbits
No full textInternational audienceConventional rabbit embryonic stem cell (ESC) lines are derived from the inner cell mass (ICM) of pre-implantation embryos using methods and culture conditions that are established for primate ESCs. In this study, we explored the capacity of the rabbit ICM to give rise to ESC lines using conditions similar to those utilized to generate naive ESCs in mice. On single-cell dissociation and culture in fibroblast growth factor 2 (FGF2)-free, serum-supplemented medium, rabbit ICMs gave rise to ESC lines lacking the DNA-damage checkpoint in the G1 phase like mouse ESCs, and with a pluripotency gene expression profile closer to the rabbit ICM/epiblast profiles. These cell lines can be converted to FGF2-dependent ESCs after culture in conventional conditions. They can also colonize the rabbit pre-implantation embryo. These results indicate that rabbit epiblast cells can be coaxed toward different types of pluripotent stem cells and reveal the dynamics of pluripotent states in rabbit ESCs
