|Rawles, Steven - Steve|
Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/13/2005
Publication Date: 2/13/2006
Citation: Subhadra, B., Lochmann, R., Rawles, S.D. 2006. Effect of dietary lipid sources on the growth, tissue composition and hematological parameters of largemouth bass (Micropterus salmoides) fed diets with poultry meal as the primary protein source [abstract]. Aquaculture America 2006 Book of Abstracts. p. 307. Interpretive Summary:
Technical Abstract: We previously showed that growth of largemouth bass (LMB) fed a diet containing different lipid (canola, chicken, or fish oil) or combination of lipids was comparable to growth of LMB fed a commercial trout diet when protein in the test diets was provided by a combination of fish meal (FM) and poultry by-product meal (PBM). In this trial we fed similar diets but completely replaced FM with PBM. The lipid sources were canola oil, chicken oil, menhaden fish oil, canola + chicken oil (1:1), and menhaden fish oil + chicken oil (1:1). Lipid comprised 10% of the diet. Each diet was fed to groups (n=4) of juvenile LMB (3.4g) for 12 wks. A trout diet (Silver cup') was fed to another group of fish as a comparison to fish fed the test diets. There were no differences in survival among treatments. Weight gain ranged from 570-1032% of initial weight and did not differ among test diets. Feed intake, feed conversion ratio and protein efficiency ratio also did not differ among test diets. However, weight gain, feed intake and protein efficiency ratio were highest in LMB fed the trout diet. Feed conversion ratio also was better (lower) in fish fed the trout diet. There were no differences in hematocrit, hemoglobin, or mean corpuscular hemoglobin concentration among fish fed the test diets. Fish fed any of the diets containing some fish oil had higher alternative complement activity than fish fed the diet containing only chicken oil. There were no differences in serum lysozyme activity among fish fed the test diets. However, all the hematological parameters were higher (better) in fish fed the trout diet. Regardless of lipid source, the complement and lysozyme activity were much lower (poorer) in LMB fed PBM-based diets than in our previous study when LMB were fed diets containing some FM. These data indicate that complete replacement of FM with PBM may compromise fish performance and health of juvenile LMB.