INFLUENCE OF DIETARY MICRONUTRIENTS ON GROWTH AND DEVELOPMENT OF DIPLOID AND TRIPLOID ATLANTIC SALMON

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1 1 2 INFLUENCE OF DIETARY MICRONUTRIENTS ON GROWTH AND DEVELOPMENT OF DIPLOID AND TRIPLOID ATLANTIC SALMON (Salmo salar) PARR Douglas Tocher (UoS) San Seastian, 15 Octoer 214 John F. Taylor 1, Christian De Santis 1, Erik-Jan Lock 2, Bente E. Torstensen 2, Daniel Leeming 3, Alan E. Tinch 4, Herve Migaud 1, Douglas R. Tocher 1, J. Gordon Bell 1 3 4

2 Introduction Possile to replace a large amount of FM and FO in feed formulation However, high dietary levels of plant proteins and/or vegetale oils (VO) can result in lower weight gain and feed efficiency Knowledge of micronutrient requirements for Atlantic salmon is limited Requirements may also differ throughout life cycle Aim: to determine micronutrient requirements of Atlantic salmon throughout life cycle in fish fed low marine ingredient diets In addition comparing diploid and triploid stock

3 Methodology Freshwater Seawater 2-25g Sep 213 Oct Solstice S1+ Smolt.5kg 1kg 2kg 3kg Apr 214 Harvest 4kg+ 2 x Ploidy 4 x Diets: S = 3% FM / 15% FO + 1% WP3 Pre-mix L1 = 15% FM / 8% FO + 1% WP3 Pre-mix L2 = 15% FM / 8% FO + 2% WP3 Pre-mix L3 = 15% FM / 8% FO + 4% WP3 Pre-mix FW SW Data Presented: Pre-seawater transfer (smolt)

4 Experimental feeds Micronutrient compositions WP3 FW Ratio NP Supplementation 1%NP Fat Solule Vitamins Vitamin A Vitamin D Vitamin E Vitamin K3 n.a Water Solule Vitamins Thiamin Rioflavin B B Niacin Pantothenic acid Folic acid Biotin Vitamin C Minerals Coalt Iodine Selenium Iron n.a Manganese Copper Zinc Calcium n.a Amino Acids Taurine Methionine n.a. not analysed yet NB: Histidine & Cholesterol added as part of the NP

5 Experimental feeds Proximate and fatty acid compositions

6 Growth Final Smolt Weight A) Diploid a Diploids Greatest growth in L2 diet Weight (g) 8 6 Growth S = L1 = L3 S gave poorest growth B) Triploid a X Data Triploids Weight (g) 6 4 Highest weight in L3 diet Growth L1 = L2 = L3 2 S gave poorest growth Diet

7 Hepatosomatic Index Viscerosomatic index 1 a a Highest VSI in S diet Diploids Lowest VSI in L1 diet Different lipid utilisation 2 etween ploidy? Diet a a No effect of diet on HSI Metaolic differences. etween ploidy? Diet VSI-HSI a Triploids 1 Greater VSI in L1 & L3 diets 8 a Increased visceral fat a deposition? Viscerosomatic index Diet Higher HSI in L1 & L3 Diets 1.8 Enlarged liver Hepatosomatic Index Metaolic imalance?.6 a no significant difference.4.2. Diet

8 Spinal Deformity Radiologically Deformed (%) Diploid Externally visile <.5% in all diets and ploidy Radiologically 2N < 3N Irrespective of ploidy: 7 6 Triploid S diet lowest prevalence L1 diet highest prevalance Deficient? Radiologically Deformed (%) Trend in low FM/FO diets Increasing NP inclusion decreases prevalence of radiological deformity (L3 < L2 < L1) Diet

9 Spinal Pathology Pathology Prevalence (%) 3 Reduced Interverteral space Diploid Compression Fusion 25 Symmetry Diploids Compression & Fusion Pathologies more dominant in L diets Fusion: L1 > L2 L3 = S L1 most fusion: Deficient diet for 2N? Reduced Spacing Compression 6 5 Triploid Fusion Symmetry Shift Pathology Prevalence (%) Diet Triploids S & L3 comparale pathology Fusion more dominant in L1 & L2 diet Deficient diet for 3N? Higher 3N requirement

10 Histology Hepatic Lipidosis (Steatosis) 3.5 Hepatic Lipidosis Score (-3) Diploid Lipidosis Score Lipidosis Score Triploid Lipidosis Score 2 Lipidosis Score 3 Hepatic Lipidosis Score (-3) Diet No significant difference etween diets within ploidy Lipidosis generally higher in triploid than diploids

11 Whole fish composition - Proximates DIPLOIDS Protein Oil Ash Moisture Higher fat content in fish fed low marine (L) feeds No effect of dietary micronutrient level in Dips Protein Oil Ash Moisture In Trips, trend for increasing fat content with increasing dietary micronutrient level No effect on protein content TRIPLOIDS

12 Whole Fish Composition - Micronutrients mg/kg ww Vitamin A Fat solule vitamins: L diets: correlation with supplementation Vit E (fish & muscle) and Vit K1 & K2 (fish) Same trend etween ploidy Triploids: tendency towards lower asolute levels mg/kg ww Diploid Triploid Niacin Diploid Triploid Copper Water solule vitamins B Vitamins e.g. Niacin (whole fish) Increases with dietary supplementation Requirement not met with NP premix (5 mg kg -1 )? No apparent difference etween ploidy Other B Vitamins to e evaluated 1. mg/kg ww Microminerals No apparent difference etween diets for Copper Requirement met y NP premix (9.1 mg kg -1 )? Many other macro & microminerals to evaluate Diploid Triploid

13 Fatty acid composition - Liver Diet S Diet L1 Diet L2 Diet L3 1 5 EPA DHA EPA DHA Dips Trips

14 16 Smolt Survival (7 days Post Transfer) Transfer Mortality (%) Diploid X Triploid Smoltification Diploids S & L2 good survival High mortality in L1 & L3 Osmotic cataracts noted under challenge Plasma Chloride (mmol/l) Diploid Sea Transfer Level 2N S 2N L1 2N L2 2N L3 Triploids L1 not transferred All diets very good survival Plasma Chloride (mmol/l) Triploid Degree-days Post Winter Solstice Sea Transfer Level Degree-days Post Winter Solstice 3N S 3N L1 3N L2 3N L3 Plasma chloride indicated all groups were seawater ready Na + K + -ATPase activity to e evaluated

15 Transcriptomic Analyses Atlantic salmon custom (TRAITS/SGP) 44K oligoarray (Agilent) Expt 1 (Effect of diet) End of FW Phase prior to SW transfer (April 214) Liver and intestine from oth Dips and Trips and all four feeds 96 arrays (2 ploidies x 2 tissues x 4 feeds x 6 iol replicates) Expt 2 (Effects of development and smoltification) Diploids Liver Time points Octoer 213 (Parr) Decemer 213 (winter solstice) April 214 (smolt, prior to SW transfer) May 214 (post-smolt, 2 weeks after SW transfer) 24 arrays (1 ploidy x 1 tissue x 4 time points x 6 replicates)

16 Conclusions FM/FO can e successfully replaced in freshwater stages 5% FM/FO reduction requires at least doule (+2%) premix addition in diploids for growth Higher Requirements for triploid growth (+4%) Requirements for growth and skeletal development may differ Metaolic differences etween Dips and Trips in relation to micronutrients Long-term effects on one and liver health to e determined