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Key Words: Oncorhynchus mykiss – rainbow trout, NutrivanceTM SPC, soy-based feed, cage culture, Lake Titicaca

EVALUATION OF SPC AS A PARTIAL SUBSTITUTE FOR FISHMEAL IN THE DIET FOR RAINBOW TROUT IN LAKE TITICACA, PERU 2013

TO

U.S. Soybean Export Council

Dr. Michael Cremer – Aquaculture Senior Program Advisor Mr. Francisco de la Torre – Amercias Regional Director

BY

Mr. Jairo Amezquita – Aquaculture Consultant

Mr. Mark Newman – Aquaculture Feed Consultant Mr. Jorge Valencia – Naltech’s Sales Representative Dr. Herbert E. Quintero – Aquaculture Consultant

Location: Lake Titicaca at Faro-Pomata Farm: Rainbow trout Cage Farm City: Potoma, Juli (Chucuito District, Puno), Peru Trial Type: Feeding demonstration in Cage Farm Treatments: Experimental diet with Soy Protein Concentrate diet SPC-

NutrivanceTM vs. a commercial diet Species: Oncorhynchus mykiss (Rainbow trout) Source of juveniles: EXECUTIVE SUMMARY: A cooperative feeding demonstration was conducted in 2013 between USSEC and Titikaka Trout Co. in Lake Titicaca, Puno, Peru. The objective of the demonstration was to show the feasibility of using a U.S. manufactured soy protein concentrate (NutrivanceTM) to replace fishmeal in the diet for cage cultured rainbow trout Oncorhynchus mykiss. NutrivanceTM is a feed grade soy protein concentrate (SPC) with high protein and low oligosaccharide content and minimal soy anti-nutritional factors. Rainbow trout performance was compared with a NutrivanceTM SPC diet and a fishmeal based diet. Results yielded similar trout performance with the two diets. The demonstration confirmed that SPC can partially replace fishmeal in the diet for rainbow trout, and that NutrivanceTM SPC is an acceptable ingredient for use in trout diets, thereby providing an alternative to fishmeal for the Peruvian trout farming industry.

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INTRODUCTION The purpose of the feeding demonstration was to evaluate the use of a U.S. manufactured soy protein concentrate (NutrivanceTM) with high protein and low oligosaccharide (raffinose 0.2% and stachyose 0.5%) content and minimal soy anti-nutritional factors as a partial replacement for fishmeal in the of rainbow trout (Oncorhynchus mykiss). The NutrivanceTM SPC diet was formulated to be nutritionally equivalent to a fishmeal-based commercial diet with 42% crude protein and 18% fat content. FEEDING DEMONSTRATION PROTOCOLS The rainbow trout feeding demonstration was conducted over a 45-day period at the Potoma cage facilities of Titicaca Trout Company in Juli, Puno, Peru (Figure 1). Trout performance was compared with two diets, an experimental diet formulated with high inclusion rates of soybean meal and NutrivanceTM SPC and a fishmeal-based, commercial diet. The NutrivanceTM SPC diet was formulated to contain 42% crude protein and 18% fat, and to be nutritionally similar to the commercial fishmeal diet (Table 1). The NutrivanceTM SPC feed was manufactured by Nutritional Technologies SAC–Naltech in Huacho, Peru. Proximal analyses of the SPC and fishmeal diets were performed by International Analytical Services SAC, an independent laboratory located in Lima, Peru (Table 2). Analyses of the two diets after manufacturing indicated the NutrivanceTM SPC had crude protein and fat contents of 42.5% and 18.6%, respectively. Crude protein and fat contents of the fishmeal based commercial diet were 42% and 14.4% respectively (Table 2). Four cages with a culture volume of 180-m3 per cage were used for the feeding demonstration, with two cage replicates for each feed treatment. Fish in cages L-1 and L-3 were fed the NutrivanceTM SPC diet, while fish in cages L-2 and L-4 were fed the commercial diet. Cages L-1 and L-2 were stocked with 4,000 and 4,100 trout, respectively, with individual average fish weights of 152 g and 166 g and coefficients of variation of 20.9 and 20.2. Cage L-3 was stocked with 6,800 trout of size 103±20.9 g (CV=20.3%), while cage L-4 was stocked with 4,800 fish of size 149±23.3 g (CV=15.6%). The four cages were oriented in the prevailing water current so that each cage received the same current flow and water exchange rate. Approximately thirty fish from each cage were sampled at 22-day intervals to determine individual fish weight and standard length. Fish were harvested after 45 days of feeding. Fish ranged in weight from 182 g to 302 g at harvest. Information was collected at harvest on total yield, average fish weight, survival, feed consumption, and feed conversion ratio (FCR). Four fish per treatment were dissected for determining the pigment level of the fillet. The following variables were calculated:

• Weight gain (WGR, %) = 100 x (final body weight - initial body weight) / initial body weight

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• Survival (%) = 100 x (final amount of fish)/(initial amount of fish)

• Specific growth ratio

(SGR) = 100 x ln (final weight/initial weight)/days of the experiment

• Condition factor (K) = 100 x (body weight, g)/(body length, cm)3

• Feed conversion ratio

(FCR) = feed fed (g, DW)/body weight gain (g) RESULTS Differences in stocking density and fish size prevented use of the cages as treatment replicates. Initial and final fish biomass for trout fed the NutrivanceTM SPC diet averaged 3.65 kg/m3 and 6.70 kg/m3. Initial and final fish biomass for trout fed the fishmeal-based commercial diets averaged 3.90 kg/m3 and 6.35 kg/m3 (Table 3 and 4). Trout fed the NutrivanceTM SPC diet in cage L-1 had the highest percentage weight gain (WGR %) at 98.7%. In comparison, trout fed the fishmeal-based commercial diet in cage L-2 had a 29% lower WGR of 70.48%. In the cages with higher stocking densities, trout in cage L-3 fed the NutrivanceTM SPC diet performed better than trout in cage L-4 fed the commercial diet, with relative weight gains of 76.7% and 59.1%, respectively. Specific growth rates (SGR) showed a similar trend, with fish in the two cages fed the NutrivanceTM SPC diet yielding the highest SGRs of 1.53%/day and 1.27%/day. SGRs for trout in the two cages fed the fishmeal-based commercial diet were substantially lower at 1.19%/day and 1.03%/day. Condition factor (K) at harvest was similar for trout in cages L-1 (SPC diet) and L-2 (fishmeal diet) that had similar stocking density and fish weight. The K factor for trout fed the SPC and fishmeal diets in cages L-3 and L-4, however, varied for the two diets and over the course of the feeding demonstration, first dropping and then increasing (Tables 3 and 4). Feed conversion ratio (FCR) was lower for fish fed the NutrivanceTM SPC diet in cage L-1, compared to fish fed the commercial diet in cage L-2, with values of 0.90:1 and 1.36:1, respectively. Feed conversion for trout fed the SPC diet in cage L-3 was 1.22:1, and 1.18:1 for trout fed the commercial diet in cage L-4 (Table 4). DISCUSSION Differences in fish stocking size and number in the four demonstration cages influenced the results of the feeding demonstration. A discussion with the farm owner, Mrs. Janeth Chara,

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confirmed this was the result of using two different batches of fish, as well as errors in the fish selection process for stocking of the cages. Problems with the stocking size are visible using a frequency diagram (Figure 3). This trend was maintained through the production cycle, with individual fish weights during the second and final samplings from 90 g to 464 g. Statistical analysis of the results did not meet the requirements for analysis of variance testing. However, the better specific growth rate (SGR), weight gain (WGR, %), and condition factor for trout fed the NutrivanceTM SPC diet indicate a potential benefit from SPC. Also, an economic analysis by Naltech indicated the SPC diet had a lower production cost for trout. The production costs for trout fed the SPC diet were $5.23/kg and $6.27/kg, respectively for cages L-1 (SPC diet) and L-3. Production costs for trout fed the fishmeal-based commercial diet in cages L-2 and L-4 were $7.25 and $7.76 per kg, respectively. It is recommended that further evaluation be conducted under more controlled conditions to verify fish performance on the SPC diet.

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TABLE 1 – – FEED FORMULATION OF THE NUTRIVANCETM SPC DIET EVALUATED IN THE RAINBOW TROUT Oncorhynchus mykiss FEEDING DEMONSTRATION CONDUCTED AT THE TITIKAKA TROUT CAGE FARM IN PUNO, PERU IN 2013. Ingredient SPC Nutrivance - 42 % CP

18 % Fat content Soybean meal 47.5% 20.00% Soy Protein Concentrate-Nutrivance, 55.37% 14.70% Fish meal, Anchovy 67,0% 22.50% Others 42.80% TOTAL 100.00%

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TABLE 2 – PROXIMATE COMPOSITION ANALYSES OF THE NUTRIVANCETM SPC 42/18 DIET AND THE FISHMEAL-BASED COMMERCIAL DIET FED TO RAINBOW TROUT Oncorhynchus mykisss IN THE 2013 CAGE FEEDING DEMONSTRATION TITIKAKA TROUT CAGE FARM, LAKE TITICACA, PUNO, PERU. SPC NutrivanceTM Commercial

Date 09/05/2013 09/05/2013

Moisture (%) 8.2 9.0

Crude Protein (%) 42.50 41.99

Crude lipid (%) 18.62 14.40

Fibre (%) 1.86 1.46

Crude Ash (%) 7.2 8.9

Carbohydrates (%) 21.62 24.25

Pepsin digestibility (%) 92.22 91.52

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TABLE 3 – PRODUCTION DATA FOR RAINBOW TROUT Oncorhynchus mykiss CULTURED IN CAGES WITH NUTRIVANCETM SPC AND FISHMEAL-BASED DIETS IN A 2013 FEEDING DEMONSTRATION AT THE TITIKAKA TROUT CAGE FARM, LAKE TITICACA, PUNO, PERU. Diet COMMERCIAL SPC-NUTRIVANCETM Cage # L-2 L-4 L-1 L-3 Volume 180 m3 180 m3 180 m3 180 m3 Date of stocking 09/17/13 09/17/13 09/17/13 09/1713 Production cycle 45-days 45-days 45-days 45-days No. organisms Stocked 4100 4800 4000 6800 Harvested 4083 4759 3952 6698 Survival (%) 99.6% 99.1% 98.8% 98.5% Average weight (g) At stocking 166±33.6 149±23.3 152±31.8 103±20.9 After 22-days of culture 255±46.6 203±39.8 236±47.8 155±23.0 After 45-days of culture 283±77.9 237±47.9 302±64.6 182±40.8 Average size (cm) At stocking 22.7 22.3 22.1 19.7 After 22-days of culture 25.9 24.0 25.5 22.5 After 45-days of culture 27.0 26.6 27.1 24.7 Condition Factor (K) At stocking 1.42 1.34 1.41 1.36 After 22-days of culture 1.47 1.17 1.42 0.89 After 45-days of culture 1.45 1.27 1.52 0.93

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TABLE 4 – PRODUCTION DATA FOR RAINBOW TROUT Oncorhynchus mykiss CULTURED IN CAGES WITH NUTRIVANCETM SPC AND FISHMEAL-BASED DIETS IN A 2013 FEEDING DEMONSTRATION AT THE TITIKAKA TROUT CAGE FARM, LAKE TITICACA, PUNO, PERU. Diet COMMERCIAL SPC-NUTRIVANCETM Cage # L-2 L-4 L-1 L-3 Volume 180 m3 180 m3 180 m3 180 m3 Date of stocking 09/17/13 09/17/13 09/17/13 09/1713 Production cycle 45-days 45-days 45-days 45-days Weight gain (WGR, %) 70.48% 59.06% 98.68% 76.70% Specific growth rate SGR (%/day) 1.19 1.03 1.53 1.27 Growth rate (g/day) 2.60 1.96 3.33 1.76 Density At stocking (kg/ m3) 3.8 4.0 3.4 3.9 After 22-days of culture 5.8 5.4 5.3 5.8 After 45-days of culture 6.4 6.3 6.6 6.8 Total Yield (kg of fish) 1153 1260 1245 1222 Biomass gained (kg of fish) 472 545 637 520 Consumed Feed (kg) 642 642 574 634 Feed Conversion Ratio 1.36 1.18 0.90 1.22 Pigment level of fillet 23.5 22.0 22.5 22.0

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FIGURE 1 – LAYOUT OF THE DEMONSTRATON CAGES FOR THE RAINBOW TROUT FEEDING DEMONSTRATION CONDUCTED WITH TWO DIETS AT THE TITIKAKA TROUT CAGE FARM, LAKE TITICACA, PUNO, PERU.  

 

 

 

 

 

 

   

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FIGURE 2 – GROWTH SAMPLING FOR THE RAINBOW TROUT FEEDING DEMONSTRATION EVALUATING NUTRIVANCETM SPC AND FISHMEAL-BASED DIETS DURING AT THE TITIKAKA TROUT CAGE FARM IN LAKE TITICACA, PUNO, PERU.    

 

 

 

 

 

 

 

 

       

 

   

 

 

 

 

 

 

 

 

   

   

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FIGURE 3 – FREQUENCY DATA FOR INDIVIDUAL FISH WEIGHTS AT STOCKING PER REPLICATE IN THE 2013 RAINBOW TROUT CAGE FEED DEMONSTRATION CONDUCTED AT THE TITIKAKA TROUT CAGE FARM, LAKE TITICACA, PUNO, PERU.  

 

 

L1-­‐SPC  L3-­‐SPC  

L2-­‐Control  L4-­‐Control  0  

2  4  6  8  10  12  14  16  18  

Trea

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Freq

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Range of weights for Individual fish weight (g)