Broken rice is a useful ingredient in aquaculture that can be used by smallholders to make farm-made feeds for fish and shrimps. Broken rice can be used as an energy source for catfish, tilapia, snakehead, milkfish and herbivore fish (Hertrampf et al., 2000). Broken rice has medium pelletising ability (5 in a scale of 10) but is now considered suitable as a replacement for maize, wheat, and tapioca starch for producing high quality extruded floating or slow sinking fish pellets (Cruz et al., 2015). Cooked broken rice can be used as a binder in moist diets (Hertrampf et al., 2000).
Catfish
Broken rice is a valuable carbohydrate source for most catfish.
Striped catfish (Pangasianodon hypophthalmus)
Broken rice was included at 30% of the diet of striped catfish fingerlings and was reported to have the highest apparent digestibility of DM, OM, gross energy and protein which made it a potential replacer for fish meal (Da et al., 2013). Similar results had been observed in an earlier experiment with the same inclusion rate (Hien et al., 2010).
Jundiá catfish (Rhamdia quelen)
Jundia catfish, an omnivorous fish tending to be carnivorous could be fed a diet containing 30% broken rice. In a comparison of plant ingredients, broken rice had higher apparent digestibility coefficients than those obtained with ground maize, citrus pulp, soybean hulls and wheat bran, but specific growth rate, final body weight and fish DM content were similar for all tested ingredients (Rodrigues et al., 2011).
Bagrid catfish (Mystus nemurus)
Bagrid catfish is a freshwater fish with high protein requirements that also needs some carbohydrates in its diet. Bagrid catfish fry could receive broken rice as a source of carbohydrates at 17% without any deleterious effect on specific growth rate. Broken rice was as efficient as ground maize, and resulted in better performance than sago flour or dextrin. Cooking broken rice did not improve its nutritive value (Hamid et al., 2011).
Hybrid Clarias catfish (Clarias macrocephalus × C. gariepinus)
Broken rice was included in hybrid catfish diets as a carbohydrate source at 30, 37, 45, 53.5 and 60% during 60 days. It resulted in higher growth rates when included at 37 to 60%. Feed conversion ratio, protein eficiency and energy retention were similar and were the highest between 37 and 53.5% inclusion (Jantrarotai et al., 1994).
Tilapia
Broken rice could be used to produce extruded feed for tilapia though it had lower floating index and water stability than cassava meal (Somboon et al., 2014).
Nile tilapia (Oreochromis niloticus)
Nile tilapia could be fed on 30% broken rice in a digestibility trial. Broken rice had much higher apparent digestibility coefficients than other plant products such as ground maize, citrus pulp, soybean hulls or wheat bran. Nile tilapia showed significantly higher growth rate and final weight when fed on broken rice rather than on other plant products (Rodrigues et al., 2011).
It was reported that average daily gain and specific growth rate were higher in Nile tilapia fed on 30-50% broken rice than on those fed on cassava meal (Somboon et al., 2014).
In tilapia extruded diets, broken rice included at 30% of the diet showed high apparent digestibility values for energy (95%) and DM (96%) and medium digestibility for protein (63%). Broken rice had the lowest available methionine and cystine compared to other carbohydrate sources (Guimaraes et al., 2008).
Red tilapia (Oreochromis spp.)
High digestibility coefficients (84% for protein) were observed for broken rice and other starch-rich ingredients such as cookie residues, macaroni residue, cassava root meal and soybean meal included at 30% dietary level in red tilapia (210 g) diets (Novoa et al., 2013).
Cyprinids
Broken rice could be used at 30% of the diet of major carp (Cirrhinus mrigala) fingerlings as a source of energy, but resulted in lower average daily gain than those obtained with maize oil cake and rice polishings (Jiang et al., 2011).