We investigated the feasibility of enhancing the reproduction of steelhead Oncorhynchus mykiss and landlocked Atlantic salmon Salmo salar in lakes where the consumption of alewives Alosa pseudoharengus and other forage fishes containing thiaminase can cause them to become thiamine deficient and thereby reduce the survival of their fry. We evaluated feeding fingerling steelhead excess thiamine hydrochloride (THC1) for 1 or 2 weeks or equimolar amounts of thiamine mononitrate, thiamine-tetrahydrofurfuryl-disulfide, benfotiamine, or dibenzoyl thiamine (DBT). We found minimal internal reserves of thiamine after 6 months. We also compared the ability of injections of thiamine and its analogs to prevent mortality in thiamine-deficient steelhead and Atlantic salmon sac fry and found all forms to be effective, although benfotiamine was the least effective on an equimolar basis. Further, we injected yearling steelhead and found that DBT was tolerated at approximately 11,200 nmol/g of body weight, about 10 times more than thiamine in any other form. When yearling steelhead were injected with near-maximal doses of thiamine hydrochloride and several analogs and then fed a thiamine-deficient diet, DBT was retained for approximately 2 years--in contrast to other forms, which were retained for less than about 6 months. Therefore, these results suggest that neither feeding nor injecting young hatchery salmonids with DBT is likely to enhance their reproduction for more than 2 years after stocking. However, injecting DBT in nearly mature fish (either cultured fish from hatcheries or wild fish captured in lakes) may provide them with enough thiamine to successfully spawn within 2 years even though they consume mainly thiaminase-containing forage fishes.

中文翻译：

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硫胺素及其类似物对硬头鲑和内陆大西洋鲑鱼的有效性和保留

我们调查了在湖泊中提高硬头鲢和内陆大西洋鲑鲑鱼繁殖的可行性，在这些湖泊中，食用 alewives Alosa pseudoharengus 和其他含有硫胺酶的饲料鱼会导致它们缺乏硫胺素，从而降低鱼苗的存活率。我们评估了饲喂鱼种过量的硫胺素盐酸盐 (THC1) 1 或 2 周或等摩尔量的单硝酸硫胺素、硫胺素-四氢糠基-二硫化物、苯磷硫胺或二苯甲酰硫胺素 (DBT)。我们发现 6 个月后硫胺素的内部储备最少。我们还比较了注射硫胺素及其类似物防止缺乏硫胺素的硬头鱼和大西洋鲑鱼囊鱼苗死亡的能力，发现所有形式都是有效的，尽管苯磷硫胺在等摩尔的基础上效果最差。此外，我们注射了一岁的钢头，发现 DBT 在大约 11,200 nmol/g 体重时是耐受的，比任何其他形式的硫胺素高约 10 倍。当一岁的钢头被注射接近最大剂量的盐酸硫胺素和几种类似物，然后喂食缺乏硫胺素的饮食时，DBT 保留了大约 2 年——与其他形式相比，保留了不到大约 6 个月。因此，这些结果表明，在放养后 2 年以上，无论是用 DBT 喂养还是注射年轻的孵化场鲑鱼都可能提高它们的繁殖能力。然而，