Corn granulometry in diets for tambaqui juvenile

SUMMARY This study aimed to evaluate the performance, carcass composition and viability of different corn granulometry (CG) in diets for tambaqui. It was distributed 160 fish (3.86±0.03g) into 20 aquaria (40-L) in a completely randomized design with five treatments and four replications. The treatments consisted of diets with different CG: 150, 300, 500, 710 and 850 µm. As performance parameters were evaluated: feed intake (FI), weight gain (WG), feed conversion rate (FCR), final total length (FTL), final standard length (FSL), height (H), specific growth rate (SGR), specific development rate (SDR) and survival (SUR). For carcass composition were evaluated moisture, crude protein, ether extract and mineral matter. For the economic analysis of diet were analyzed the total cost of production (TCP), cost of feed per kg weight gain (CFK) and the index of economic efficiency (IEE). Data were subjected to analysis of variance at 5% probability and polynomial regression. There was quadratic effect for the variables FI, WG, FCR, FTL, FSL, H, SGR and SDR, obtaining the best results, respectively, for CG estimated at 530.22; 555.40; 597.47; 566.75; 562.07; 557.48; 562.70 e 555.68 µm. There was no influence of CG on the carcass composition. There was quadratic effect for TCP and CFK variables, with higher values for CG estimated at, respectively, 600.44 and 602.11 µm. It is concluded that CG of 500 µm is indicated to tambaqui feed.

【摘要】本研究旨在评估不同玉米粒度（corn granulometry，CG）日粮对坦巴奎鱼的养殖性能、胴体组成与饲喂可行性。试验将160尾初始体重为3.86±0.03g的坦巴奎鱼随机分配至20个40升水族箱中，采用完全随机设计，设置5个处理组，每组4个重复。各处理组日粮的玉米粒度分别为150、300、500、710及850 µm。本研究测定的养殖性能指标包括：采食量（feed intake，FI）、增重（weight gain，WG）、饲料转化率（feed conversion rate，FCR）、最终总长度（final total length，FTL）、最终标准体长（final standard length，FSL）、体高（height，H）、比生长速率（specific growth rate，SGR）、比发育速率（specific development rate，SDR）及存活率（survival，SUR）。胴体组成指标包括水分、粗蛋白、粗脂肪及矿物质含量。日粮经济分析指标包括总生产成本（total cost of production，TCP）、每千克增重饲料成本（cost of feed per kg weight gain，CFK）及经济效率指数（index of economic efficiency，IEE）。所有数据采用5%显著性水平下的方差分析与多项式回归进行统计分析。结果显示，FI、WG、FCR、FTL、FSL、H、SGR及SDR均呈二次效应，其最优玉米粒度估计值分别为530.22、555.40、597.47、566.75、562.07、557.48、562.70及555.68 µm。玉米粒度对坦巴奎鱼的胴体组成无显著影响。TCP与CFK变量呈二次效应，当玉米粒度分别为600.44 µm与602.11 µm时，二者取值最高。综上，500 µm的玉米粒度适用于坦巴奎鱼配合饲料。