In this study, the impact of adding 10% or 20% torula yeast (PB TY10 and PB TY20) to a fishmeal-free diet on digestibility and growth of juvenile rainbow trout was assessed. The yeast diets were compared with a plant-only diet (PB) and a diet containing 20% fishmeal (FM). The apparent digestibility of dry matter, protein, energy, and ash of yeast in trout (~120 g) were 78.6%, 93.8%, 84.8%, and 48.7%, respectively. All PB diets had higher protein digestibility and PB TY20 had higher ash digestibility than the FM diet. To assess growth, trout (~44 g) were divided into triplicate tanks (30 per tank) and fed one of the four experimental diets for 12 weeks. The PB diet resulted in lower growth and daily feed intake (p < 0.05), but adding yeast significantly improved them. Final weight of PB TY10 did not differ significantly from that of FM. Expression of oclna and cldn15 in the proximal intestine increased in trout fed yeast (p < 0.05). Expression of tlr2, mcsfr, and tnfa, as well as the plasma lysozyme concentration, increased with PB TY20 (p < 0.05). In conclusion, torula yeast has the potential to improve the robustness and growth of rainbow trout in the context of fishmeal-free diets.

中文翻译：

---

在虹鳟鱼 (Oncorhynchus mykiss) 饲料中用圆酵母部分替代植物蛋白源可促进生长并改善与免疫状态相关的因素

在本研究中，评估了在无鱼粉日粮中添加 10% 或 20% 圆酵母（PB TY10 和 PB TY20）对虹鳟幼鱼消化率和生长的影响。将酵母饮食与纯植物饮食 (PB) 和含有 20% 鱼粉的饮食 (FM) 进行比较。鳟鱼（约120克）中酵母干物质、蛋白质、能量和灰分的表观消化率分别为78.6%、93.8%、84.8%和48.7%。所有 PB 日粮均比 FM 日粮具有更高的蛋白质消化率，并且 PB TY20 的灰分消化率更高。为了评估生长情况，将鳟鱼（约 44 克）分为三个水箱（每个水箱 30 条），并喂食四种实验饲料中的一种，持续 12 周。 PB 饮食导致生长速度和每日采食量较低（p  < 0.05），但添加酵母可显着改善它们。 PB TY10 的最终重量与 FM 没有显着差异。在喂鳟鱼的酵母中，近端肠道中oclna和cldn15的表达增加 ( p  < 0.05)。tlr2、mcsfr和tnfa的表达以及血浆溶菌酶浓度随 PB TY20 的增加而增加 ( p  < 0.05)。总之，圆酵母有潜力在无鱼粉饮食的情况下提高虹鳟鱼的健壮性和生长。