SYMPOSIUM OLMIX

RÉSUMÉ

María García¹, María Angeles Rodríguez¹, Mustapha Berri², Christel Rousseaux³ and Pi Nyvall-Collen^1 
1Olmix Group, Bréhan, France; ²INRA, Nouzilly, France; ³Intestinal Biotech Development, Lille, France

The cell wall of marine algae is mainly composed of water soluble sulfated polysaccharides with several biological activities such as modulation of the immune response and reinforcement of gut barrier function. The present study aimed at assessing the ability of different seaweed extracts on improving gut health. The first part of the word tested a specific extract from green algal Ulva sp to upregulate the expression of immune mediators and the molecular mechanisms underlying this immunomodulatory activity by identifying the cell receptor and the signaling pathways involved. The second part of the work focussed on the the potential enhancement properties of a red algal extract from Solieria Chordalis on intestinal integrity using in vitro cell models HT-29 MTX and Caco-2 cells, under physiological and inflammatory conditions. Results showed that Ulva sp extract has the capacity to upregulate the expression of immune mediators: TNFα, CCL20, IL-1α, TGF-β that are involved in cell differentiation and proliferation, recruitment of immune cells and anti-inflammatory activities. Ulva sp extract interacts with TLR4 and TLR2 and leads to rapid activation of transcription factors PI3K and NF-κB. The red algal extract was shown to upregulate the expression of different target genes related to claudin-2, ZO-1 and ZO-2. The red algal extract upregulates the expression of mucin targeted genes: MUC4, MUC2, MUC5B and MUC5AC. The combination of both algal extracts can reinforce gut health targeting barrier function which is the first line of mucosal defense and via modulation of local innate and adaptive immune responses and induction of anti-inflammatory activities. The use of macroalgal sulfated polysaccharides can play an important role within the reduction of antibiotics in farms. 

RÉSUMÉ

Marie Gallissot¹, Rodrigo Jacob², Luiz Fernando Albino², Horacio Rostagno², Raquel Pereira¹, Mariel Tavares¹, Maria Angeles Rodriguez*^1
1Olmix, Bréhan, France; ²Department of Animal Science, University of Viçosa, Viçosa, Minas Gerais, Brazil

Improving feed digestibility is a multi-faceted issue in animal nutrition. It contributes to improve livestock farming sustainability, by optimizing the use of available resources and by reducing environmental emissions, while increasing farming profitability. This study was set up to evaluate the effect of supplementing an algae-clay complex (ACC) on digestive enzyme activity and growth performance of broiler chickens fed with a corn-soy diet. The experiment was conducted at the Federal University of Viçosa (Brazil). Six hundred and sixty 1-day-old Cobb 500 male chicks were randomly distributed to 3 treatments with 10 replicates per treatment and 22 chicks per experimental unit, allocated to 1 of 3 groups receiving different diets: the standard diet (C) based on corn and soybean meal, the test diet 1 (T1), being the standard diet supplemented with 0.1% of ACC, and the test diet 2 (T2), being the standard diet supplemented with 0.2% of ACC. Animal’s performance was evaluated by measuring weight gain, feed consumption and feed conversion ratio for each feeding phase. Moreover, duodenum samples were collected at 35 days, two hours after the last feeding, from 3 chickens per replicate (30 chickens/treatment) to perform digestive enzyme activity assays. The activity of amylase (using starch) and chymotrypsin (using BTEE substrate) were measured by spectrophotometer in kinetic assay. Results showed a tendency to increase weight gain for groups T1 and T2 compared to control, though it was not statistically significant Feed conversion ratio was decreased in both test groups compared to control during the grower period (-4% and -5% respectively, P=0.043) and the whole period (-3%, P=0.038). These results were comforted by an increased activity of amylase (+25%, P<0.01) and chymotrypsin (+13 to 20%, P<0.001) in the duodenum in T1 and T2 groups compared to the control group, reflecting an improved capacity of digestion of the diet by birds supplemented with the algae-clay complex. No dose effect of the ACC product was observed. In the end, this study shows a positive effect of the algae-clay complex on feed efficiency of broiler chickens fed a corn-soy based diet. Its use at 0.1% of the feed seems the most interesting to improve performance and profitability.