BACKGROUND Developments in the production of aquacultural salmonid feeds in the last 20 years have led to extruded diets with extremely low water content and a shift from mainly marine fish based ingredients towards plant content. These changes expose the industry to the vagaries of the highly dynamic plant protein market. Resulting variations in the precise composition of aqua feeds may carry unpredictable consequences for water quality, since some plant ingredients cause undesirable reductions in the mechanical stability of faeces. Dietary supplements known as binders that enhance the stability of faeces have the potential to mitigate these issues, but may also bring negative effects. OBJECTIVE AND METHODS The present study employs an in vitro model to perform the first fundamental rheological characterization of salmonid chyme, and a factorial experiment designed to investigate the impacts of the presence of rheologically active substances. RESULTS The highest mean viscosity values were measured for a treatment containing a 2:1 ratio of tara gum:xanthan gum, resulting in chyme four times more viscous than a control formulation containing the same amount of water. Shear resistance was quantified by analyses of slopes fitting the frequency sweep measurements. CONCLUSIONS These data open a new statistical approach to monitoring the consequences of market-driven changes in aqua feed composition and their impacts on the nutrition, health or performance of farmed fish.

中文翻译：

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鲑鱼食糜体外模型的流变学表征，用于定量饲料成分的变化。

背景技术在过去的20年中，水产鲑鱼饲料的生产发展已导致含水量极低的膨化饲料以及从主要以海鱼为主的原料向植物含量的转变。这些变化使行业面临高动态植物蛋白市场的变化。水产饲料精确组成的变化可能会给水质带来不可预料的后果，因为某些植物成分会导致粪便机械稳定性的降低。膳食补充剂称为粘合剂，可以增强粪便的稳定性，可以缓解这些问题，但也可能带来负面影响。目的和方法本研究采用体外模型对鲑鱼食糜进行了第一个基本的流变学表征，以及旨在研究流变活性物质存在的影响的析因实验。结果对于比例为2：1的塔拉口香糖：黄原胶的处理，测量到了最高平均粘度值，导致食糜的粘性比含相同量水的对照配方高四倍。抗剪强度通过对与频率扫描测量值相符的斜率进行分析来量化。结论这些数据为监测市场驱动的水产饲料成分变化及其对养殖鱼的营养，健康或性能的影响提供了一种新的统计方法。黄原胶，其食糜的粘性是含有相同量水的对照配方的四倍。抗剪强度通过对与频率扫描测量值相符的斜率进行分析来量化。结论这些数据为监测市场驱动的水产饲料成分变化及其对养殖鱼的营养，健康或性能的影响提供了一种新的统计方法。黄原胶，其食糜的粘性是含有相同量水的对照配方的四倍。抗剪强度通过对与频率扫描测量值相符的斜率进行分析来量化。结论这些数据为监测市场驱动的水产饲料成分变化及其对养殖鱼的营养，健康或性能的影响提供了一种新的统计方法。