|Lee, K. J.|
|Powell, M. S.|
|Hardy, R. W.|
Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2013
Publication Date: 10/29/2013
Citation: Lee, K., Rahimnejad, S., Powell, M., Barrows, F., Smiley, S., Bechtel, P.J., Hardy, R. 2013. Salmon testes meal as a functional feed additive in fish meal and plant-protein based diets for rainbow trout(Oncorhynchus mykiss walbaum)and nile tilapia(Oreochromis niloticus L.) fry. Aquaculture Research. 10:1111-12313. Interpretive Summary: In this study, we designed a series of feeding trials using both fish meal based, and all plant protein based diets where the dietary protein sources were partially substituted with salmon testes meal. The feeding studies were carried out on three fish species; including white sturgeon, Nile tilapia, and rainbow trout, to provide preliminary data in ascertaining the nutritional value and feed ingredient potential of salmon testes meal. Seafood processing by-products have become more useful as fish feed ingredients, in part because of the pursuit the eco-friendly production systems recycling discarded food wastes, and in part because of the ecological concerns surrounding the whole forage fish meal industry. In this study, we investigated the potential of salmon testes meal made from Alaska seafood processing by-products as a dietary animal protein source to replace fish meal protein or as a protein feed attractant at the early stages of fish growth. We chose Nile tilapia and rainbow trout as representative fresh water and herbivorous/carnivorous fish species. White sturgeon was chosen as one of newly developing omnivorous aquaculture species. Results indicated testes meal can be used to replace fish meal, or as a feed attractant for Nile tilapia, white sturgeon, and rainbow trout in their early growth stages. Supplementation of salmon testes meal in plant protein based diets results in better fish growth if the amino acids lysine and methionine are supplemented. These results indicate that salmon testes meal can be used in partial replacement for fish meal, or as a feed attractant for fishes at their early growth stages. Remaining to be elucidated in future studies is the highest possible replacement level of salmon testes meal that does not allow any undesirable effects on growth performance.
Technical Abstract: We report that salmon testes meal (TM) produced from Alaskan seafood processing byproducts is a potential protein source for aquafeed formulations. A series of feeding trials was conducted using three different fish species; including Nile tilapia, rainbow trout, and white sturgeon at their early growth stages. In the first experiment, five iso-caloric and iso-nitrogenous diets were formulated consisting of a fish meal-based control diet (FM), a FM diet where 20% fish meal was replaced by TM (FMTM), a plant protein-based diet (PP) and, two PP diets where 30% soy protein concentrate was replaced by TM (PPTM) or fish meal (PPFM). White sturgeon and Nile tilapia fry were fed the diets for 6 and 4 weeks, respectively. In the second experiment, Nile tilapia and rainbow trout fry were fed another five diets, where three PP-based diets were supplemented with lysine and methionine, for 4 and 9 weeks, respectively. In the first experiment, both fish species fed the FMTM diet showed a comparable growth performance with those fed the FM diet. For PP-based diets, tilapia fry fed PPTM diet showed significantly lower growth and feed efficiency than the fish fed PPFM diet, and similar trend was observed in white sturgeon. In the second experiment, however, supplementation of lysine and methionine to the PP-based diets resulted in comparable growth performance in both Nile tilapia and rainbow trout fry to those of fish fed the FM diet. Salmon TM inclusion in both the FM-and PP-based diets resulted in a higher growth performance for rainbow trout, and significantly increased growth performance was observed in all the FM-based diets; therefore, these results indicate that salmon TM can be used in partial replacement for FM or as a feed attractant for fishes at their early growth stages.