Physical feed properties affect feed utilization in fish. To study how physical feed properties affects feed intake, digestibility and gastrointestinal passage, two feeds with identical formulation, but different physical properties, were produced. Diet 1 was produced with lower water stability than Diet 2. Each feed was produced in three batches, added lanthanum (La), ytterbium (Yb) or yttrium (Y) as indigestible markers. The feeds were fed to Atlantic salmon (1,047 g), one daily meal, for 29 days. Feeds labelled with La were used the first 26 days, feeds with Yb on day 27 and feeds with Y on days 28 and 29. Faeces were collected 8, 16, 24, 32, 40 and 48 hr after feeding on day 27 and analysed. La, Yb and Y in faeces originated from feed eaten on days 26, 27 and 28, respectively. Marker concentrations in faeces showed that some Yb appeared in faeces 8 hr after feeding. After 16 hr, the passage rate was higher for Diet 1 than Diet 2. After 48 hr, both feeds had passed almost completely through the gastrointestinal system. The apparent digestibility of lipid was higher in Diet 1 than in Diet 2. There was no significant difference in feed intake.

中文翻译：

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物理饲料特性会影响大西洋鲑，鲑鲑鱼的胃肠道通过率

饲料的物理特性会影响鱼类的饲料利用率。为了研究物理饲料特性如何影响饲料摄入，消化率和胃肠道通行性，制备了两种配方相同但物理特性不同的饲料。饮食1的水稳定性低于饮食2。每种饲料分三批生产，添加镧（La），y（Yb）或钇（Y）作为难消化的标记。将饲料每天喂一顿，饲喂大西洋鲑鱼（1,047克），持续29天。在最初的26天使用带有La标记的饲料，在第27天使用Yb饲料，在第28和29天使用Y饲料。在第27天喂食后第8、16、24、32、40和48小时收集粪便并进行分析。粪便中的La，Yb和Y分别来自第26、27和28天食用的饲料。粪便中的标记物浓度显示，喂食后8小时粪便中出现了一些Yb。16小时后，饮食1的通过率高于饮食2。48小时后，两种饲料几乎都完全通过了胃肠道系统。饮食1中脂质的表观消化率高于饮食2中的脂质。饲料摄入量无显着差异。