A growth trial using hatchery-reared grouper was carried out to study the effects of stocking density on feed intake and subsequent growth. Contrary to common perceptions, fish stocked at the highest density had higher feed intake and body weights.
Uneaten or undigested feed and their metabolic byproducts contribute to declines of water quality in aquaculture systems. Accordingly, feed and feeding techniques require continuous review. Reducing overfeeding is an important opportunity for improving feed conversion ratios.
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Turbot are typically fed diets containing 45 to 65 percent fishmeal. In a study that gave turbot feed with 40 percent soy protein concentrate, the fish had decent growth and excellent survival.
Poor-quality ingredients can’t become good-quality ingredients. Quality protein is essential for the healthy growth of any omnivorous or carnivorous aquaculture species. Insect meals seem to fill this need, and their mass-scale production appears to be sustainable.
Shrimp farmers in Australia believe that applying smaller amounts of feed regularly is an effective strategy for maximizing feed conversion in ponds. By providing more time for shrimp to rest between eating cycles, consistently lower FCRs have been achieved.
Incorporating feed manufacturing into an aquaculture business offers greater and more efficient product access, control and logistics, as well as additional profit potential. A feasibility study that plans for growth and includes both a business plan and economic analysis is a must.
A feeding demonstration in Costa Rica evaluated the partial replacement of fishmeal in diets for spotted rose snappers with soy protein concentrate (SPC). It found no significant difference between the performance of fish fed an SPC-based diet and those that received commercial fishmeal-based diets.
A deficiency of cholesterol in shrimp diets can result in slower growth and higher mortality rates. A study by the authors investigated krill meal as a partial replacement for a cholesterol supplement in diets for juvenile Litopenaeus vannamei shrimp.
Reduced performance in fish fed high-soy feeds has been blamed on antinutrients, low methionine content and palatability issues. Pretreatment to inactivate anti-nutritional compounds and supplementation with amino acids improves soy-based feed performance, but not to control levels.
Feed cost per unit gain (F.C./U.G.) is a metric frequently used in animal production systems to evaluate the effects of feed costs on production profitability. F.C./U.G. is calculated by multiplying the feed-conversion ratio by the unit cost of feed.
A study found that feed for salmon and trout had higher organic carbon concentrations than did catfish, shrimp and tilapia feeds. Nitrogen and phosphorus concentrations were similar among salmon, trout and shrimp feeds, and higher than those in catfish and tilapia feeds.
Liposomes, synthetic microparticles originally developed for the pharmaceutical industry, can be produced for ingestion by rotifers and artemia. A study found that yellowtail larvae fed rotifers enhanced with liposomes containing taurine had improved growth.
Although today’s soybeans offer many benefits, farmers can also plant alternatives, sometimes on the same farms that raise genetically modified beans. Organic beans meet specific market demands, and a conventionally bred non-GMO bean has been developed for use in aquafeeds for carbohydrate-intolerant marine fish.
Feed trays are typically used to avoid overfeeding in aquaculture production systems. They are sometimes used to deliver 100 percent of the feed that is fed, and other times a small number of trays are used as a guide to evaluate broadcast feeding techniques.
A study that used DDGS to partially replace soybean meal as the primary protein source in diets for juvenile white shrimp found the growth of shrimp significantly decreased when DDGS replaced soybean meal.