Effluent profile of commercially used low-phosphorus fish feeds.
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.
Sugiura
Shozo H
SH
Department of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103-2714, USA.
Marchant
Daniel D
DD
Kelsey
Kevin
K
Wiggins
Thomas
T
Ferraris
Ronaldo P
RP
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
D014866:Waste Products; D014874:Water Pollutants, Chemical; D010758:Phosphorus