Impact of shrimp physiology on feed formulation and processing

With annual production ranging around 3 to 3.5 million tonnes a year, farmed shrimp is a major aquaculture product. Shrimps are crustaceans which means that their physiology and behaviour are different from those of other aquatic species. These features must be considered in the composition of their intended feed. How can the feed formulation process take shrimp’s behavioural patterns into account?

Farmed shrimps mainly belong to two species: the omnivorous white shrimp (Vannamei Peaneus) and the black tiger (Peaneus monodon).
Whatever their feeding habits shrimp are benthic; that is to say they feed on the bottom of the pond. Hence they need to be supplied with a sinkable feed that will stay at the bottom. Such feed is often pressed (or pelleted) into compact shapes, allowing the pellets to sink in water.
In addition, shrimp need to find their feed appetising so they want to ingest it. Since they are naturally attracted to some feed components, chemotaxis (chemical attraction) is the means by which they manage to find their feed. Many compounds and materials are said to be attractants to shrimp.

Shrimps feed themselves by "nibbling" on pellets.
This "nibbling" action has two purposes:

• to reduce the size of particles in order to facilitate their ingestion. Given this characteristic shrimp's pellets need to be made of extremely fine particles. To this end the raw materials that compose them are micronized, meaning that they undergo sustained grinding.
• to select what they ingest. As opposed to fish, shrimps have the ability to sort components out of their pellets. It is therefore preferable to include a small amount of non-palatable raw materials in their feed formulation.

In aqua farming, the time gap between the distribution of feed pellets and their consumption by shrimp usually lasts up to a few hours. This length varies depending on the water temperature, the physiological state of the population and frequency of meal distribution.
Two other aspects in feed formulation need therefore be the object of careful attention:

• binders: to avoid the leaching of feed constituents, pellets should not dissolve during their period of immersion. The binding properties of the ingredients used are therefore of paramount importance, whether they are raw materials or specific additives.
• ingredient insolubility is another key factor to take into account in order to avoid feed leaching. In this respect, premixes, vitamins, and minerals must be adjusted to the shrimp's feeding behaviour.

Thanks to their thorough knowledge of shrimp nutritional requirements, Techna's experts offer customised solutions in order to assist you with your feed formulation needs. To learn more, please contact us!