Evaluation of skin mucous cells of Atlantic salmon ( Salmo salar ) - PowerPoint PPT Presentation

Evaluation of skin mucous cells of Atlantic salmon ( Salmo salar ) fed plant- based diets and probiotics Nimalan N , Fečkaninová A, Koščová J, Mudroňová D, Vatsos I, Kiron V, Sørensen M

Content 1. Background 2. Methodology 3. Results 4. Summary 5. Conclusion

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology Nutrient sources in Norwegian salmon feeds 100% 1 2 2.2 3.7 9.6 8.4 11.2 11.2 90% 12.5 Percentage of nutrient sources 80% 24 22.2 19.2 70% 60% 35.5 Microingredients 50% Starch 31.1 36.7 Plant oil 40% 16.6 Plant protein 65.4 30% Marine oil 10.9 20% 33.5 Marine protein 24.8 10% 18.3 0% 1990 2000 2010 2013 Modified from Ytrestøyl et al., 2015

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology Effects of changing dietary ingredients Plant-based diets Marine ingredients • Nutritional profile • EPA & DHA Favourable Unfavourable • n-3 : n-6 ratio • Presence of ANFs • Health impacts • Enteritis (SBM) • Mucosal health

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology Aim of the study – investigate the effect of feeding plant-based diets, with or without probiotics, on the skin mucous cells of Atlantic salmon ( Salmo salar ).

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology Experimental diets Ingredient composition (%) of experimental diet - without probiotic + with probiotic Feed ingredients Diet1- Diet1+ Diet 2- Diet2+ Diet3- Diet3+ Fishmeal 50 50 10 10 30 30 Fish oil 25 25 7.7 7.7 26.4 26.4 Wheat source 18.8 18.8 16 16 16.5 16.5 SPC + PPC + Corn 0 0 38 38 0 0 Rapeseed oil 0 0 19.8 19.8 0 0 Soybean meal 0 0 0 0 20 20 Other ingredients 6.2 6.2 8.5 8.5 7.1 7.1 Probiotic (log10 CFU/g) 0 8.75 0 8.75 0 8.75 Source: Unpublished work, Sørensen et al., 2019

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology Experimental Design, Fish and Feeding Diet 1 (D1) Diet 2 (D2) D1- D3- D2- D1+ Diet 3 (D3) - : without probiotic + : with probiotic D3+ D3+ D1+ D2+ D2+ D1- D3- D2- Experimental set up: Water quality: • Atlantic salmon, fed to satiation, 6 • Temperature = 7.6 o C • Salinity = 35‰ weeks duration • Flow through tanks, 1000 l, 35 fish/ tank • Oxygen saturation = above 85% • Initial mean weight = 147 g • Photoperiod = 24 h

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology Sampling and data collection Sampling (Dorsal skin, 0.5 cm 2 ) 12 fish/treatment Fixation (4% formalin,72 h) Decalcification (10% formic acid, 5 h) Processing (for 17 h) Embedding (Cross, Paraffin) Sectioning (at 4 µm) Staining (H&E, AB-PAS)

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology Skin mucous cell parameters 108 images per diet Total area of epidermis Total area of mucous cells 1) Total area of mucous cells/ 1 μ m 2 of epidermis (percentage) - ME 2) Average size (µm 2 ) of mucous cell - MA 3) Number of mucous cells/ 1000 μ m 2 of epidermis - NM

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology Data Analysis • Normality of data • Homogeneity of variance • Two-way ANOVA • Microphotograph – Image J (1.52) • R software environment (Version 3.6.1)

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology 1) Total mucous cells area per epidermis area (ME) 20% 15% ME Two-way ANOVA: 10% Diet: p = 0.148 Probiotic: p = 0.533 Interaction: p = 0.790 5% 0% D2- D2+ D1- D1+ D3- D3+

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology 2) Average size (area) of mucous cell (MA) 160 120 MA (µm 2 ) Two-way ANOVA: Diet: p = 0.072 80 Probiotic: p = 0.381 Interaction: p = 0.936 40 0 D2- D2+ D1- D1+ D3- D3+

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology 3) Number of mucous cells per epidermis area (NM) 1.5 A B A a b NM (per 1000 µm 2 ) 1 Two-way ANOVA: Diet: p = 0.001 Probiotic: p = 0.008 Interaction: p = 0.542 0.5 0 D2- D2+ D1- D1+ D3- D3+

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology • Size and number of skin mucous cells: 1) 15 to 17 % epidermis area is covered by mucous cells. 2) Average size (area) of mucous cell is 128 to 149 µm 2 . 3) 0.9 to 1.3 mucous cells per 1000 µm 2 of epidermis. • No significance difference: 1) Total area of mucous cells per 1 μ m 2 of epidermis (ME). 2) Average size (area) of mucous cell (MA). • Significance difference: 3) Number of mucous cells per 1000 μ m 2 of epidermis (NM).

1. Background 3. Results 4. Summary 5. Conclusion 2. Methodology • Diet affected number of skin mucous cells. • Probiotic affected number of skin mucous cells. Dietary intervention influences the number of skin mucous cells of Atlantic salmon.

Our research team… Prof. Ioannis Vatsos Prof. Mette Sørensen Prof. Kiron Viswanath Dr. Adriána Fečkaninová Prof. Jana Koščová Prof. Dagmar Mudroňová

Thank you very much for your attention Tusen takk