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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #146053
Title: EVALUATION OF PROTEIN REDUCTION AND LYSINE SUPPLEMENTATION OF PRODUCTION DIETS FOR CHANNEL CATFISH ICTALURUS PUNCTATUS

Author
item Gaylord, Thomas
item SEALEY, WENDY - TEXAS A&M UNIV.
item GATLIN, DELBERT - TEXAS A&M UNIV.

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/21/2002
Publication Date: 7/1/2002
Citation: GAYLORD, T.G., SEALEY, W.M., GATLIN, D.M. EVALUATION OF PROTEIN REDUCTION AND LYSINE SUPPLEMENTATION OF PRODUCTION DIETS FOR CHANNEL CATFISH ICTALURUS PUNCTATUS. NORTH AMERICAN JOURNAL OF AQUACULTURE. 2002. v.64. p. 175-181.

Interpretive Summary: An experiment was conducted to test if the amount of protein fed to channel catfish could be reduced and if supplementing lysine to the diets would help reduce the protein needs of the fish. Experimental diets consisted of three practical diets containing either 30% crude protein (control), 25% crude protein, or 25% crude protein supplemented with 0.5% lysine HCl to provide the same level of lysine as the control diet. Final harvest data showed that fish fed the 30% protein diet had a higher percentage of marketable fish. Total yield of fish fed the 30% crude protein diet averaged 16,546 kg/ha, while fish fed the 25% crude protein diet and the 25% crude protein diet supplemented with 0.5% lysine had average yields of 14,838 kg/ha and 14,363 kg/ha, respectively. Feed conversion ratios were unaffected by dietary protein level or lysine supplementation. Water quality was affected by dietary treatment with total ammonia nitrogen concentrations in ponds with fish fed the 25% crude protein+lysine diet significantly elevated (0.6 + 0.39 mg/L) compared to control ponds (0.54 + 0.30 mg/L), and the 25% crude protein treatment (0.47 + 0.32 mg/L) had reduced ammonia concentrations compared to controls. Based on this study, it appears that reduction of dietary crude protein from 30 to 25% had limited effects on channel catfish production. Dietary treatments also had quanitatively small effects on water quality, and supplemental lysine provided no appreciable benefits to yields or water quality.

Technical Abstract: A 2-year continuous production trial was conducted in earthen ponds to evaluate lysine supplementation of practical diets as a means to reduce the need for total dietary protein and limit nitrogenous waste production of channel catfish. Experimental diets consisted of three practical diets containing either 30% crude protein (control), 25% crude protein, or 25% crude protein supplemented with 0.5% lysine HCl to provide the same level of lysine as the control diet. Final harvest data showed a significant (P<0.05) effect of diet on fish size, with ponds containing fish fed the 30% crude protein diet having a higher percentage of marketable fish. Total yield of fish fed the 30% crude protein diet averaged 16,546 kg/ha, while fish fed the 25% crude protein diet and the 25% crude protein diet supplemented with 0.5% lysine HCl had average yields of 14,838 kg/ha and 14,363 kg/ha, respectively, which were not statistically different from that of the 30% crude protein diet. Feed conversion ratios were unaffected by dietary protein level or lysine supplementation. Water quality was affected by dietary treatment with total ammonia nitrogen concentrations in ponds with fish fed the 25% crude protein+lysine diet significantly elevated (0.6 + 0.39 mg/L) compared to control ponds (0.54 + 0.30 mg/L), and the 25% crude protein treatment (0.47 + 0.32 mg/L) had reduced ammonia concentrations compared to controls. Nitrite concentrations were significantly higher in control ponds compared to other treatments, but nitrate levels were unaffected by dietary treatment. Based on this study, it appears that reduction of dietary crude protein from 30 to 25% had limited effects on channel catfish production. Dietary treatments also had quanitatively small effects on water quality, and supplemental lysine provided no appreciable benefits to yields or water quality.