Aquaculture (fish) nutrition

Aquaculture requires optimization of nutrition to efficiently raise fish for the purpose of food production. Fish nutrition entails providing nutrients and energy sources essential for fish health, growth and reproduction. It is therefore important to provide safe and nutritious fish; however, there are many issues related to fish nutrition that need to be considered in order to achieve balance in food production and sustainability. Some of these include: feed and nutrient efficiency, overfeeding and waste, unsustainable feed ingredients, fish health issues, biotechnology and human health concerns. Ultimately, each of these issues can affect the final product for human consumption, either nutritionally, environmentally or economically. Achieving a balance between efficient and safe food production with environmental sustainability can be a challenge for the industry. The research platform thus ensures development of quality, economically viable and environmentally friendly fish feed made from cost effective locally available ingredients, which can support fast growth rates of various farmed fish species. Furthermore, the platform focuses on appropriate use and management of the formulated feed used by famers and offers technical support to feed producers in fish feed formulation and production.

Achievements

ARDC formulated fish feed that contributed to increased aquaculture production from 5,000 metric tons annually in mid 2000s to 100,000 tons annually by 2016. The use of formulated feed has been adopted by about 40% of the active fish farmers in the country and over 90% of all commercial fish farmers. Other technologies developed included:
i. Identified natural growth promoters (phytogenics) for Nile tilapia and developed protocol for using them in Nile tilapia diets
Constraint addressed:Low fish feed utilization efficiency leading to slow fish growth
ii. Developed technology for improving catfish hatchery productivity using live food, a water flea (Moina micrura) for weaning fish fry.
Constraint addressed: Limited supply of African catfish fry due to high mortality (<5%) of fry as a result of using inappropriate feed for weaning the fry.
iii. Developed a protocol for manipulating water from saline crater lakes of Western Uganda to enable Artemia production in Uganda
Constraint addressed: High cost of imported Artemia (live food) leading to its low use by farmers and subsequently poor fish survival in hatcheries.
iv. Collected baseline data on the prevalence of mycotoxins in fish feed and farmed fish to guide quality control.
Constraint addressed:Lack of information on mycotoxin contamination levels and quality control strategies for commercial fish feed and farmed fish.
v. Developed model diet formulations for producing cost effective fish feed using non-conventional plant and animal protein sources.
Constraint addressed: High cost of fishmeal (Silver fish locally known as mukene) and soy sourced protein for fish feed development. Alternative protein sources investigated included Oilseed cakes such as sunflower, cottonseed, soybean, sesame, blood meal, insect larvae and Caridina (fresh water shrimp).
vi. Developed a model diet formulation for producing quality and cost-effective fish feed using non-conventional carbohydrate sources.
Constraint addressed: Lack of information on the use of sorghum as an alternative source of energy to the more expensive maize.
vii. Characterized the digestive system of Nile perch and determined its nutritional requirements to aid development of artificial diets for farming the fish.
Constraint addressed: Lack of feeding strategies for Nile perch for intended domestication.
viii. Developed feeding strategies for Labeovictorianus under culture conditions.
Constraint addressed: Lack of feeding strategies for Labeo for intended domestication.
ix. Developed feeding chart for Nile tilapia fed on diets containing mainly plant ingredients.
Constraint addressed: Lack of fish feeding guides for fish farmers at different agro-ecological zones customized to different fish species and types of fish feed.
x. Developed guidelines for preparation, handling and storage of farm made feed and non-conventional fish feed ingredients.
Constraint addressed: Fast spoilage of farm-made feed and non-conventional fish feed