ABSTRACT This study aimed at assessing productive growth performance, blood physiology, intestinal histology, body composition and bone mineralization parameters of silver catfish juveniles fed diets containing different inclusion levels of sorghum, considering three combinations (0%, 50% or 100%), supplemented or not with phytase enzyme (0 and 1500 FTU kg−1). The apparent feed conversion and specific growth rate were benefited by supplemented diets (P < 0.05). The highest protein efficiency rate was obtained for the supplemented diet containing corn (P < 0.05). The viscerosomatic index was lower when corn/sorghum diet (P < 0.05) was offered, whilst the hepatosomatic index was lower in corn and corn/sorghum diets regardless of supplementation (P < 0.05). Regarding blood parameters, variations were observed (P < 0.05), however they were kept within the limits for the species. Histomorphometry variables also displayed variations, which were observed in fish fed with sorghum and sorghum/corn diets, supplemented or not (P < 0.05). Proximate composition of carcass varied for both aether extract and mineral matter for supplemented diets (P < 0.05). A variation of Ca content (P < 0.05) regarding bone mineralization was observed when corn and sorghum were used in the same proportion. Sorghum replacement of corn in diets for R. quelen may be a feasible alternative, and phytase supplementation with improves fish performance.

中文翻译：

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在银鲶鱼（Rhamdia quelen）日粮中用高粱和植酸酶补充剂替代玉米：生长性能、生理变量和骨矿化

摘要 本研究旨在评估银鲶鱼幼鱼的生产性生长性能、血液生理学、肠道组织学、身体成分和骨矿化参数，其中考虑了三种组合（0%、50% 或 100%），补充高粱。或不使用植酸酶（0 和 1500 FTU kg-1）。表观饲料转化率和比生长率受益于补充日粮（P < 0.05）。含有玉米的补充日粮获得了最高的蛋白质效率（P < 0.05）。当提供玉米/高粱日粮时，内脏指数较低（P < 0.05），而无论是否补充，玉米和玉米/高粱日粮的肝体指数较低（P < 0.05）。关于血液参数，观察到变化（P < 0.05），然而，它们被控制在物种的范围内。组织形态计量学变量也显示出变化，这在用高粱和高粱/玉米饲料喂养的鱼中观察到，补充或不补充（P < 0.05）。补充饮食的乙醚提取物和矿物质的胴体大致组成各不相同（P < 0.05）。当玉米和高粱以相同比例使用时，观察到钙含量在骨矿化方面的变化（P < 0.05）。在 R. quelen 的饮食中用高粱替代玉米可能是一个可行的替代方案，并且补充植酸酶可以提高鱼的生产性能。补充日粮的乙醚提取物和矿物质的胴体近似组成各不相同（P < 0.05）。当玉米和高粱以相同比例使用时，观察到钙含量在骨矿化方面的变化（P < 0.05）。在 R. quelen 的饮食中用高粱替代玉米可能是一个可行的替代方案，并且补充植酸酶可以提高鱼的生产性能。补充日粮的乙醚提取物和矿物质的胴体近似组成各不相同（P < 0.05）。当玉米和高粱以相同比例使用时，观察到钙含量在骨矿化方面的变化（P < 0.05）。在 R. quelen 的饮食中用高粱替代玉米可能是一个可行的替代方案，并且补充植酸酶可以提高鱼的生产性能。