White shrimp diet with animal proteins

Growth of shrimp was not affected by the lower cost diets containing varying amounts of poultry by product meal and soybean meal. Growth is affected when diets do not contain any marine meal. Low levels of hydrolysed feather meal require supplementation with lysine and methionine.

At present farmed shrimp are the largest consumers of fishmeal within the aquaculture sector, consuming an estimated 964,000 tonnes of fishmeal in 2007. The aquaculture sector consumed a total of 3.83 million tonnes or 68.4% of the total global fishmeal production in 2007. Apart from the limited supply and availability, there is an urgent need to reduce the dependency of the rapidly growing aquaculture sector upon this limited and potentially food-grade marine fishery resource.

Figure 1. Estimated consumption of fishmeal by the aquaculture sector in 2007 (values given in thousand tonnes).

 

The present paper summarises the results of a feeding trial conducted with Pacifc white shrimp in Indonesia. The overall goal of the study was to improve the economic viability and sustainability of marine shrimp culture operations through the development of cost-effective fishmeal-free feeds using terrestrial animal by-product meals as the main protein source.

A 10-week feeding trial was conducted with white shrimp (Litopenaeus vannamei) from juvenile to market size at the experimental diet testing facilities of PT. Luxindo Internusa, Anyer, Java, Indonesia. Four animal by-product meals and a control marine meal were evaluated as detailed
in Table 1.

Table 1. Composition of meals.

Thirteen experimental test diets were formulated, a standard control diet containing 8% fishmeal and 2% squid meal, and 12 diets containing various levels of fishmeal and marine protein/lipid replacement. All diets were formulated to contain 33-35% crude protein and 5.5-6.5% crude lipid (Table 1).

All 13 experimental diets were produced at PT Luxindo Internusa in Jakarta (Indonesia) using a commercial shrimp feed mill (IDAH 53SA with triple conditioners), with 1,600 kg of each diet produced and observations taken during the production process so as to ascertain the effect of ingredient use on energy usage, ease of production,physical characteristics, water stability and handling.

Shrimp and experimental culture conditions Juvenile Pacifc white shrimp of the same strain and size, were obtained from a local shrimp hatchery and stocked within 48 round black-coated fberglass microcosm tanks (1m3 water volume, with a conical bottom)at an initial stocking density of 75 shrimp/tank (equivalent to a shrimp density of 75/m3 water volume), with three tanks allotted per dietary treatment (Photo 1).


       Experimental tank system used for conducting shrimp feeding trial

Water within the microcosm tanks was continuously mixed and aerated using a diaphragm air diffuser placed at the bottom of the tank (so as to keep all particulate matter in suspension) and a zero-water-exchange green water management system operated within the tanks for the duration of the 70-day culture trial. Air was continuously supplied to all experimental tanks using a 2HP air blower and freshwater added to tanks as required so as to replace evaporative losses.

In addition to the above mentioned 13 dietary treatments operated on a zero-water exchange management system, a control running water treatment was also implemented using diet 2 (Table 2).

Table 2. Shrimp feed formulations and composition (values expressed on a percent as fed basis).

Diurnal water temperature, dissolved oxygen, pH and salinity measurements were made within the experimental tanks throughout the study, together with an estimate of the quantity of suspended microbial `foc'''' present within the water column of the experimental tanks using a volumetric sedimentation column.

Experimental shrimp were fed at regular 3h intervals over a 24-h period (8 feedings per day) by hand application using the same fxed dietary feeding regime for all treatments. All experimental animals were weighed individually at the start and end of the 70-day feeding
trial, and by group weighing at bi-weekly intervals so as to determine average body weight and estimate shrimp survival.

Data obtained from the experiments, which had a completely randomized design with 3 replicates per treatment, were analysed by one-way analysis of variance (ANOVA) to determine if significant differences existed among treatment means. All statistical analyses were performed using SPSS 16.0 (SPSS Inc., Chicago, Illinois, USA. Differences were considered signifcant at the 5% level of probability.

The feeding trial commenced on July 3, 2009 and ended on September 12, 2009.

Results of feeding trial
Water quality

Water quality within the experimental tanks was determined at 8.00 am and 4.00 pm over the course of the 10-week experiment and varied as follows in Table 3.

The growth performance of shrimp fed the experimental test diets is shown in Table 2 and Figures 3 to 5.

Figure 2. Mean weekly growth response of experimental shrimp fed experimental diets.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3. Mean biweekly growth response of experimental shrimp fed experimental diets.

 

 

 

 

 

 

 

 

 

 

 

 

Excellent shrimp growth and survival was observed over the course of the feeding trial, with animals reaching a fnal body weight of 17.6 to 18.9g (commercial size), with no significant difference observed between treatments 1, 2, 3, 4, 7 and 9 in terms of fnal body weight and treatments 1 through 10, and 13 (Table 4). Moreover, the best overall food conversion ratios were observed for treatments 1, 4 and 9, respectively; overall trial FCRs ranging from 1.65 (treatment 9) to 1.67(treatment 1 and 4).

Table 4. Growth performance of shrimp fed the experimental diets over a 10 week feeding period.

Figure 4. Final feed conversion ratio observed for shrimp fed the experimental diets after 10 weeks.

 

 

 

 

 

 

 

 

 

 

 

Figure 5. Final survival observed for shrimp fed the experimental diets after 10 weeks.

 

 

 

 

 

 

 

 

 

 

 

 

From Table 2 it can be seen that the most expensive diet in terms of raw material cost was the control fishmeal containing diet (treatment 1; IDR 6,128/kg), with the best equally performing diets being 7.9%  cheaper (treatment 3; IDR 5,644/kg), 6.5% cheaper (treatment 9; IDR 5,728 /kg), 5.7% cheaper (treatment 4; IDR 5,779/kg), 5.2% cheaper (treatment 7; IDR 5,810/kg) and 3.1% cheaper (treatment 2; IDR 5,936/kg).

Discussion

The results clearly show the nutritional and economic efficacy of totally replacing fishmeal and squid meal within commercial shrimp feeds by using.

Feed grade poultry by-product meal (60/10.9/15.9/5.6 CP/EE/Ash/Moisture): up to a dietary inclusion level of between 20 and 25% of the total diet (treatment 3 and 4), with supplemental methionine, and increasing dietary soybean levels from 16% to between 20 and 25%, with ingredient cost savings of between 5.7 and 7.9% compared with respect to a similar diet containing 8% fishmeal and 2% squid meal.

Hydrolyzed feather meal (83.7/5.3/1.2 CP/EE/Ash): up to a dietary inclusion level of 5% (treatment 7) of the total diet, with supplemental lysine and methionine, and decreasing dietary soybean levels from 16% to 14%, with ingredient cost savings of 5.2% compared with respect to a similar diet containing 8% fshmeal and 2% squid meal.

Surprisingly, shrimp fed the same diet with no supplemental amino acids (treatment 8) showed no significant differences in final body weight or feed effciency with animal fed the supplemented diet, with consequent ingredient cost savings of 8.4% compared with a diet containing 8% fishmeal and 2% squid meal.  



     The PT Luxindo Internusa team; Uus Sugema (left), Adi Nugroho (middle) and Choiruz Zaudjat (right).

Spray dried blood meal (88.8/0.9 CP/EE): up to a dietary inclusion level of 2.5% of the total diet (treatment 9), with supplemental methionne, and increasing dietary soybean levels from 16% to 20%, with ingredient cost savings of 6.5% compared with respect to a similar diet containing 8% fishmeal and 2% squid meal.

Meat & bone meal from pure beef (50/10.5/28.7/3.5): results with 5% meat and bone meal (treatment 6) were disappointing, with shrimp displaying significantly lower final body weight (P<0.05) and poorer FCRs compared with the other treatments.

The results obtained with rations devoid of all marine protein and lipid sources (treatment 10 to 13) were disappointing, with the best results obtained with the diet containing 30% poultry by-product meal and 1% blood meal with supplemental lysine; the other treatments displayed significantly reduced shrimp growth and feed efficiency compared the control diet (Table 2). Surprisingly, there was no significant difference between shrimp fed diet 12 and 13; the former containing a complete vitamin and trace mineral premix and the latter containing no vitamin or mineral premix. It is also important to note that treatment 13 also recorded the highest foc concentration within experimental tanks.

Finally, as expected, shrimp reared in running water (treatment 14) displayed the worst growth response and feed efficiency compared with shrimp fed the same diet under zero-water exchange conditions (diet/treatment 2). However, it is also important to note that the water temperature within the clear running water tanks were at least 2 degrees lower than tanks with a zero-water exchange management system.