Effect of Polymethylolcarbamide (Urea Formaldehyde Condensation Polymer) on Growth and Tissue Formaldehyde Residues in Shrimp

Abstract

Toxicity of the urea formaldehyde resin pellet binder polymethylolcarbamide (Basfin^R) was determined in 28-day feeding trials conducted in tanks with Penaeus vannamei Boone, 1931. Levels of polymethylolcarbamide ranging from 0.25 to 8% did not affect shrimp survival. However, growth of shrimp fed feeds containing more than 0.5% polymethylolcarbamide was less than that of shrimp fed control feeds without polymethylolcarbamide. Growth was reduced 58% by feed containing 8% polymethylolcarbamide, and 19 to 27% by feeds containing 1 to 4% polymethylolcarbamide. In a separate trial, growth was reduced 29 and 30% by feeds containing 0.5 and 1% polymethylolcarbamide, respectively. Growth was reduced by polymethylolcarbamide both in feeds that were extruded without heating using alginate as the binder, and in feeds that were bound by polymethylolcarbamide with the addition of steam, heat and pressure. Formaldehyde residues in muscle increased linearly with polymethylolcarbamide level in feed. However, at levels of polymethylolcarbamide recommended by manufacturers for pellet binding, predicted levels of formaldehyde in shrimp tissues would be lower than those reported in stored fish and shrimp. Under conditions of semi-intensive pond culture where natural foods were present, a 28-day feeding trial conducted in outdoor pens indicated that growth and survival were not affected by 0.5% polymethylolcarbamide.