title: Effluent profile of commercially used low-phosphorus fish feeds.
abstract: Excess phosphorus (P) in aquaculture feeds contributes to the eutrophication of natural waters. While commercially available low-P (LP) fish feeds have been developed, there is uncertainty about their potential to reduce effluent P while maintaining fish growth relative to regular P (RP) feeds. We therefore simulated commercial aquaculture conditions and fed for 55 days rainbow trout (approximately 190 kg/raceway, n = 3 raceways/diet) RP (1.4% total P) and LP (1.0%) feeds then determined effluent P levels, fish growth, and feed costs. Excretions of fecal-P and soluble-P, but not particulate-P, in effluents were greater in RP than in LP ponds. Fish growth, bone-P and plasma-P were similar between diets, demonstrating that LP feeds can lower effluent P levels without compromising growth. Costs were 0.97 dollars/kg fish production for LP feeds, and 0.74 dollars/kg for RP. Because feed is the largest variable cost in commercial aquaculture, the use of LP feeds can significantly increase production costs.
authors.affiliation: Department of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103-2714, USA.
authors.forename: Shozo H
authors.initials: SH
authors.lastname: Sugiura
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Marchant
authors.forename: Kevin
authors.initials: K
authors.lastname: Kelsey
authors.forename: Thomas
authors.initials: T
authors.lastname: Wiggins
authors.forename: Ronaldo P
authors.initials: RP
authors.lastname: Ferraris
mesh_terms: D000821:Animal Feed; D000818:Animals; D017756:Aquaculture; D003365:Costs and Cost Analysis; D005068:Eutrophication; D005243:Feces / Q000737:chemistry; D017686:Oncorhynchus mykiss / Q000254:growth & development*; D010758:Phosphorus / Q000032:analysis* / Q000633:toxicity; D014866:Waste Products; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity
chemical_list: D014866:Waste Products; D014874:Water Pollutants, Chemical; D010758:Phosphorus