by Warren G. Dominy, Ph. D.
|The Aquatic Feeds section of the Nutrition
Department conducts applied research focused on developing defined
feeds that meet nutrient requirements of the cultured animals
and defined processing parameters for the equipment that manufactures
these feeds, for both the commercial aquaculture sector and the
institute’s own research.
The information generated in the Aquatic Feeds Processing Laboratory
is essential for formulating and manufacturing cost effective,
nutritionally complete, highly digestible, water stable, and
environmentally friendly feeds. The research includes identification,
analysis, and practical testing of ingredients to determine applicability
in aquatic feeds.
Analyzing ingredients includes determining nutrient profiles,
quality, digestibility, binding characteristics, and costs.
Physical analysis and characterization of the ingredients and
the finished products are very important to aquatic feeds. Particle
size reduction and the uniformity of mix are two important parameters
measured. Aquatic animals in early life stages are much smaller
and eat tiny amounts of feed, compared with the smallest animal
in the terrestrial feed industry, the 40-gram baby chick.
We harvest market-size shrimp at 15-25 grams. (An ounce is 25
grams.) Imagine stocking a 1-gram shrimp and feeding it 10 percent
of its body weight per day.
If the feed contains 20 or more ingredients, those ingredients
have to be ground down to a particle size small enough so that
every ingredient in the correct proportions can be uniformly
mixed and compacted into a package weighing only 0.1 gram.
It is also important that the feed ingredients in these 0.1-gram
packages do not disintegrate when placed in water, which would
destroy the carefully balanced nutrient content of the feed.
For these reasons, optimal processing parameters and equipment
for manufacturing these types of feeds are also critically important.
In most feeds, the gelatinization of starches and the development
and setting of wheat gluten in the feed manufacturing process
will determine the water stability of the feed. Measuring and
documenting the parameters of time, temperature, and moisture
in the feed manufacturing process for each formulation is important
to maintaining a consistently water-stable aquatic feed.
All feeds manufactured in the Aquatic Feeds Processing Laboratory
are subjected to a rigorous quality control program that ensures
feeds meet various industry and research standards for physical,
sanitary, and nutritional quality and content, prior to feeding.
Nutritional checks include proximate analysis (protein, fat,
ash, moisture, and fiber), major and trace minerals, amino acid
and fatty acid profiles. The physical parameters tested include
ingredient particle size, uniformity of mix, pellet specific
density, durability index, attractiveness, palatability, and
The Nutrition Department welcomes HPU researchers and students
for collaboration and internship opportunities. E-mail Gary Karr,
director of Communications and Education, at gkarr@oceanic institute.org.