摘要
There is the need to enhance feed efficiency and growth of rainbow trout to reduce production costs of cultured fish. This study conducted a 3 × 4 factorial experiment with three graded levels of grain distiller dried yeast (GDDY) protein (0%, 50%, 75%) as replacement for fishmeal and four different prebiotics inclusion levels (0% (control), 0.4%, 1% mannooligosaccharides (MOS), and 1% GroBiotic A). The feeding trial was conducted for 12 weeks during which fish were fed daily to apparent satiation. Growth of rainbow trout was not affected by replacement of fishmeal with GDDY, but feed conversion ratio (P 0.0001) was greater at the highest level of GDDY inclusion. Increasing GDDY inclusion significantly increased feed intake (P 0.00015), which resulted in poor feed utilization. Acetic (P = 0.1994), propionic (P = 0.8037), butyric (P = 0.6268), valeric (P = 0.5877), and isovaleric (P = 0.5919) acids profiles did not differ by diet nor with inclusion of MOS or GroBiotic A. Whole shotgun metagenomic analyses of the gastrointestinal tract (GIT) microbiota revealed enrichment in the fungal phyla Ascomycota and Basidiomycota and the bacterial phylum Actinobacteria in the GDDY-fed fish compared to those fed the control fishmeal-based diet, which may be reflective of the species endogenous in GDDY. Microbial genes involved in branched-chain amino acid metabolism (glutamate, glutamine, aspartate) (P = 0.028) and glutamate dehydrogenase clusters (P = 0.0192), were also elevated in the fish fed the 75% GDDY-based diet. The results from this study indicate the potential for microbially-mediated catabolism of the non-essential amino acids, and suggest this activity may significantly influence efficient utilization of dietary nitrogen in the yeast-based protein diet.
摘要译文
有必要提高饲料效率和虹鳟的生长，以降低养殖鱼的生产成本。这项研究进行了一个3×4析因实验与三个分级水平的谷物干酵母（GDDY）蛋白质（0％，50％75％）替代鱼粉和四种不同的益生元包含水平（0％（对照），0.4％，1％甘露寡糖（MOS）和1％GroBiotic A）。饲养试验进行了12周，在此期间鱼每天喂食至明显的饱食。用GDDY替代鱼粉不会影响虹鳟的生长，但饲料转化率（P 0.0001）在包含GDDY的最高水平时更高。 GDDY的添加显着提高了采食量（P 0.00015），导致饲料利用率差。乙酸（P \x3d 0.1994），丙酸（P \x3d 0.8037），丁酸（P \x3d 0.6268），戊酸（P \x3d 0.5877）和异戊酸（P \x3d5919）酸分布没有差异的饮食，也没有纳入MOS或GroBiotic A.（GIT）微生物群显示GDDY喂养的鱼中真菌门Ascomycota和Basidiomycota和细菌门Actinobacteria的富集与喂食对照鱼粉基础饮食的那些相比，这可能反映了GDDY中内源性的物种。涉及支链氨基酸代谢的微生物基因（谷氨酸，谷氨酰胺，天冬氨酸）（P \x3d 0。028）和谷氨酸脱氢酶簇（P \x3d 0.0192），在饲喂基于75％GDDY的饮食的鱼中也升高。这项研究的结果表明微生物介导的非必需氨基酸分解代谢的潜力，并建议这种活动可能会显着影响酵母蛋白饮食中饮食氮的有效利用。
Omolola C.Betiku[a][b];Carl J.Yeoman[b];T.Gibson Gaylord[a];Glenn C.Duff[d];TimothyHamerly[c];BrianBothner[c];Stephanie S.Block[e];Wendy M.Sealey[a];. Differences in amino acid catabolism by gut microbes with/without prebiotics inclusion in GDDY-based diet affect feed utilization in rainbow trout[J]. Aquaculture, 2018,490: 108-119