Here are a few points from the PB presentation.

The immense variety of cultured finfish species hampers efforts to simplify production industry wide. Approximately 170 taxa are currently cultured, including carnivores, herbivores, planktivores, and omnivores, each posing its own set of nutritional demands .

Fish meal has proven to be an excellent dietary protein source for finfish, leading to its description as an ��ideal protein.�� The ideal protein concept is based on the premise that if the amino acid profile of the feed mimics the whole-body amino acid profile of the animal being fed, protein utilization and growth should be maximized

Lipids, fatty acids, and their derivatives play a role in virtually every physiological process that occurs and for this reason dietary lipid composition and content represent a massive sector of overall nutrition. Nowhere is this more true than in finfish nutrition where lipid can exceed protein in the body composition of finfish, a testament to the physiological and energetic importance of this nutrient class (Tocher2003). Aside from physiological importance, lipids are indispensable energy sources, especially for finfish, which are not well-adapted to carbohydrate utilization.

Dietary protein and energy must be kept in proper balance because a deficiency or excess of dietary energy can reduce growth rates. Fish fed diets deficient in energy will metabolize more expensive dietary protein to meet energy requirements. Excess dietary energy can decrease protein intake and suppress growth.

finfish do not require carbohydrates in their diet, � complex carbohydrates cannot be digested and utilized efficiently by most finfish species. A general dichotomy exists in the carbohydrate digestive ability of warmwater omnivores and herbivores versus the inability of coolwater and coldwater carnivores, which lack the appropriate function necessary for digestion of carbohydrates.

�For this reason, diets fed to these fish rarely contain more than 20% complex carbohydrate

Conversely, warmwater omnivores or herbivores (e.g., channel catfish, tilapia, common carp, and white sturgeon) adapt well to diets containing as much as 40% dietary carbohydrate .

Although vitamins and minerals are required in minute amounts compared with protein, lipid, and so forth, they are critically important, � Every micronutrient has a deficiency disease associated with it, the effects of which are sometimes irreversible or fatal. For a few vitamins and most minerals, excess can be equally detrimental, resulting in toxicity.


Abstract from 1 study

Reviews in Fisheries Science
Volume 11, Issue 4, 2003

Dietary Carbohydrate Utilization by

DOI:
10.1080/10641260390260884
David A. J. Stonea
pages 337-369
� Published online: 24 Jun 2010
Abstract
Aquaculture production is forecast to nearly double by the year 2010. Increased production can only be sustained with a concomitant increase in the production of aquafeeds. Presently, the protein source of choice in most aquafeeds is fish meal. Global fish meal production has remained relatively static over the past two decades, and there is no evidence to suggest that it will increase in the future. Therefore, alternative protein sources to fish meal will have to be found. Plant protein sources have been identified to have the greatest potential to replace fish meal protein. However, plant ingredients contain significant quantities of carbohydrates. The ability of fish to utilize dietary carbohydrates as energy sources to spare protein for growth varies, both among and within species. This review discusses the variability of carbohydrate utilization by fish commonly produced by aquaculture. Factors that affect carbohydrate utilization as an energy source to spare protein are carbohydrate origin, inclusion content, physical state, and molecular complexity. There appears to be potential for the use of supplemental enzymes to enhance carbohydrate utilization; however, care must be exercised with the use of such products as some of the breakdown products, particularly from nonstarch polysaccharides, such as galactose and xylose, are not tolerated by most fish if digested. The increased availability of these monomers may be detrimental to fish growth performance and health. Warmwater omnivorous fish have a greater potential to utilize dietary carbohydrate as an energy source to spare protein, than do coldwater and carnivorous species which utilize dietary carbohydrate poorly or not at all. This will place restrictions on the use of plant protein sources, which contain significant quantities of. carbohydrate in diets for coldwater and carnivorous fish. Consequently, the production costs of diets for warmwater omnivorous species will be cheaper than for coldwater and carnivorous species. This may have implications in the future for the selection of suitable species of fish to provide protein for human consumption.


Last edited by ewest; 01/06/16 04:48 PM.