Rainbow Trout Feed

A Brief Overview on  the trout’s food

As the most expensive part of fish farming isrelated to the food, the nutritive topics must be considered such as the method for producing the food ( by extruder machine or pellet press, …), the chemical composition of the food, amount of food, type of food and time of feeding  or some factors like the rate of water solubleoxygen, temperature of water and the size of fish.

As we know, the fishes are considered as the coldblooded animals, whose body metabolism rate depends on the temperature of the environment or the water in which they live. As the temperature raises , their breathing goes up and receiving or removing the residual goes up too. The fishes’ tolerance towards the heat depends on their type and species. The warm water fishes have more tolerance towards the raise of temperature, but the cold water fishes can tolerate the raise of temperature  only up to the limited range. If the temperature of the water increases, the rate of dissolving of the water-soluble gases decreases, their breathing and nutrition would be disrupted  and their growth would be interrupted consequently they die. On the other hand, as the temperature of the water decreases, the ratio between digestion and absorption would be decreases, so that the fishes refuse from eating the food.

therefore, for the cold water fishes such as rainbow and red spotted trout, the best temperature is from 12 to 16 centigrade including a 7-12 milligram oxygen in a liter.

Trout is a kind of hunter fish, it selects his food or bait by his power of seeing, the food must be floating or in the position that the fish can reach it easily.

Raman Aquatic Industries

Presently, Raman Aquatic Industries prepares, produces and controls all kinds of the food for the warm water fishes, cold water fishes, sturgeon, ornamental fishes and shrimps by using the new technology of twin extrusion and benefitting from the latest methods of rationing.

Producing the food at Raman Aquatic Industries Company, using the most advanced and recent machines of the world not only caused the significant progress in producing the food of aquatic and other animals but also has the main role in exploitation of the resources and decreasing the waste of the food resources, increasing the production efficiency and less destruction of the environment.

The extrusion process described as the processing of the raw materials of food at high temperature, within a short time, under the conditions  of mixing the humidity, heat and pressure.

During the food preparation process, by extrusion method, the raw materials or complete food were backed under the continuous pressure (if necessary between 10 to 40 times), then due to a sudden pressure drop, the materials were expanded and become porous.

The extruded food has the significant role in increasing the production efficiency due to have all advantages of pellet food including non- separation of its components and being homogenous, transporting with the minimum of soil, better nutrition and increasing  the digestibility.

The unique characteristics of the food special for the trout produced by Raman Aquatic Industries are as follows:

These unique characteristics cause the fishes in the pool to use the productive food equally and according to their need:

-The significant improvement of the food conversion factor

-Lacking the anti -nutritive substances and all pathogenic microbes

-Providing all food needs of the trout, increasing the durability  time of nutrients, specially micronutrients(vitamins and minerals) in water.

-Floating on the water

-Dropping the food as zigzag after ending of floating and in a long time, and non-destruction of its physical shape of the productive food in a short time.

-Leaching loss and pollution loss of the food in the fish farming pools due to have a proper stability and consistency in water.

-Increasing the resistance of the fishes against the probable stress such as illness, displacement and biometry

-Improving the immunity response of the farming fishes against the vaccination

-The possibility of increasing the number of farming fishes in per cubic meter of the pool water (minimum to 40 %)

-Minimizing the waste and loss of the food during its movement and transporting

-Having the capacity of increasing the oil of the food up to 25%

-Decreasing the Ammoniac Production in the pool water

Calculating Daily Fishe’s Meal

If feeding is done by hand , the daily food of fish specially, trout , is  calculated , according to the method of the next page and food is distributed in different times (3-4 times) from the walls of the pool.

Method for calculating the daily food of Fishes:

After releasing the fries in water , and after passing the feeding time(usually one week) , for being informed about the status of growth and amount of food , the farmers must measure the weight of 0.5-1 % of the whole herd and defining the weight average of the fishes , act the biometry . By biometry , it can be aware of the rate and monotonousness of the growth of feed Conversion Ratio  and growth index.

The farmers take act towards solving the problem , through inserting the correct information in the biometry table , in case of any problems in the growth rate or loss of the food .

The Raman suggests that the farmers directly connect with the Research & Development Group  (R&D) for taking the necessary instructions to reach the maximum production.

For determining the conditions of farming and growing the fishes usually the following parameters are used:

The average of a piece of fish =the net weight of total fishes÷ number of the weighted fishes

Feed Conversion Ratio =the amount of total consumed food at distance of 2 biometry ÷the rate of producing the meat in distance of 2 biometry

Growth Index = w × (the weight of the fishes × 100) ⁄ L3 (The Total Average Length)

if the gained number is < 1, it shows the fish is thin  and if the number=1, it shows the proper weight of the fish and if the number >1, it shows the fish is fat.

Total amount of fish’s food = the fish’s biomass × the percent of feeding

The fish’s biomass = The average weight of fish × the number of fish

The amount of feeding comes in the feeding tables suggested by Raman Aquatic Industries (table 2 & 3) regarding the weight of fish and temperature of the water.

It is recommended that  maximum every 15 days, the fish’s biomass is determined, and according to this, the amount of food to be calculated.

Generally, the feeding amount must not be more than 5 to 10 percent of the total feeding , in a day.

Example: There are 8000 fishes in a pool which are farming with the average weight of 60 grams and average temperature of 14-16 centigrade, for calculating the daily consumed food of these fishes :

Total weight of the fishes

8000 × 60 = 480,000 grams

Then by referring to table 2, temperature column and weight row would be determined, extracting the respective number from the table, in the above example, 1.76 was obtained that is related to 25-75 gram fishes, in 14-16 centigrade water. Then the daily required food of the warm water fishes was calculated as follows:

480000 × 1.76 = 8448 gr

Therefore, the fishes of this pool must feed at minimum daily 8.448 kg food with the size of 2.3 millimeter, in 4 to 5 times.

Nutritive and Farming Recommendations:

1-The rate of water soluble oxygen must be more than 6 milligram/liter. The oxygen taken by the fish depends on some parameters such as water temperature, size and weight of the fish, activity and feeding of the fish, at 12-16 centigrade, the average oxygen taken by the fish is about 600 grams per kilogram of feeding in a day or in average : 480 milligram per hour, for each kilogram of fish.

2- Increasing the net oxygen of water caused a raise in the oxygen density in the entryway water at 200 to 300 percent. The oxygen density in the pool must be more than 65% of the saturated water of the region.

3- By adding the salt to the water and fixing the chlorine in 150-200 milligram per liter of the pool water, it is possible to prevent the poisoning resulted from the nitrite in fish.

4- Some carbon dioxide is created in the pool due to the breath of the fishes and bacteria exist in water. It is suggested that the carbon dioxide must not increase more than 12 milligram per liter. A raise of carbon dioxide causes the stress and raise of the feed Conversion Ratio.

5- As a raise of nitrite or ammonia in water , the feeding must be interrupted and the water would be cleaned.

6- As the temperature of water increased, the saturate rate of water soluble gas decreased. As the water temperature increased or decreased  from 12-16 centigrade, a dysfunction in a fish’s digestive system would be seen and caused the growth decreases and feed conversion Ratio increases.

7- Sweetwater fishes are obliged to consume more energy for swimming and control themselves against the water flow, in case of maintaining in a fast flows in comparison to the time maintained in a pool.

This is suggested that the fish farmers present the complete information to the food productive factory about the conditions of fish farming pool before ordering the food.

8- The metabolism rate of a small fish is more than that of the big fish. In aquatic farming, it is clear that the smaller fish needs more food, according to the weight unit of the body.

9- It is suggested that during farming period at least 5 to 6 times,  grade the fishes. For preventing stress and fatalities consulting with the expert of fish feeding, at least three days before grading.

10- Daily check the fish’s behavior, in case of decreasing the appetite, gathering the fishes at the entry and exit areas , act to preventive measures.