Insect meals are potential alternatives to fishmeal because they contain high protein, have short life cycle and can be farmed. Fishmeal is a sole ingredient of the standard feed for the production of mono-sex tilapia fry. Attempts have been made to avoid or reduce fishmeal use exploring alternatives. The present study tested field cricket (Gryllus bimaculatus) meal (FCM) replacing fishmeal (FM) at the rates of 0, 20, 40, 60, 80 and 100% to evaluate the effects on sex-reversal efficiency, survival, growth and feed utilization. Six diets with similar levels of crude protein (55.7 ± 0.2%) were formulated and fed to Nile tilapia fry (8.0 ± 0.1 mg) stocked in 18 aquaria (100 L) at the density of 300 each. They were fed five times a day for 21 days as per the standard protocol. They were also nursed additional 63 days. Results showed that replacement of fishmeal by FCM did not affect the efficiency of conversion, the percentage of males remained high (range 97.2%–98.6%) regardless of the replacement rate. During sex reversal, when the replacement of fishmeal increased from 20% to 80%, growth, survival and feed utilization indicators continue to improve. However, 100% replacement of fishmeal by FCM reduced the growth and survival. Broken line analysis showed that 80% replacement of fishmeal resulted in highest survival during sex reversal and 85% replacement during the first nursing and no effects on second nursing. The highest biomass gains, apparent digestibility and feed conversion efficiencies were obtained at 80% replacement for all the phases. Replacement of 80% fishmeal by FCM increased 9% cost of the SRT diet and 12% of the nursing diet based on the current prices in Thailand.

中文翻译：

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田间蟋蟀 (Gryllus bimaculatus) 粉 (FCM) 在尼罗罗非鱼 (Oreochromis niloticus) 鱼苗的性别逆转和护理日粮中替代鱼粉

昆虫粉是鱼粉的潜在替代品，因为它们蛋白质含量高，生命周期短，可以养殖。鱼粉是用于生产单性罗非鱼鱼苗的标准饲料的唯一成分。已经尝试避免或减少鱼粉的使用，探索替代品。本研究测试了田野蟋蟀（Gryllus bimaculatus) 鱼粉 (FCM) 以 0、20、40、60、80 和 100% 的比例替代鱼粉 (FM)，以评估对性别逆转效率、存活、生长和饲料利用率的影响。配制了具有相似粗蛋白水平 (55.7 ± 0.2%) 的六种日粮，并以每条 300 条的密度将尼罗罗非鱼鱼苗 (8.0 ± 0.1 mg) 饲养在 18 个水族箱 (100 L) 中。按照标准方案，它们每天喂食五次，持续 21 天。他们还额外接受了 63 天的护理。结果表明，用 FCM 替代鱼粉不影响转化效率，无论替代率如何，雄鱼的比例仍然很高（范围为 97.2%–98.6%）。在性别逆转期间，当鱼粉替代量从20%提高到80%时，生长、成活和饲料利用指标不断提高。然而，用 FCM 100% 替代鱼粉会降低鱼粉的生长和存活率。折线分析表明，80%的鱼粉替代导致性逆转时的存活率最高，第一次哺乳时替代鱼粉为85%，对第二次哺乳没有影响。所有阶段的生物量增益、表观消化率和饲料转化效率均在 80% 的替代率下获得最高。根据泰国目前的价格，用 FCM 替代 80% 的鱼粉使 SRT 饮食的成本增加了 9%，护理饮食的成本增加了 12%。所有相的表观消化率和饲料转化率均在 80% 的置换率下获得。根据泰国目前的价格，用 FCM 替代 80% 的鱼粉使 SRT 饮食的成本增加了 9%，护理饮食的成本增加了 12%。所有相的表观消化率和饲料转化率均在 80% 的置换率下获得。根据泰国目前的价格，用 FCM 替代 80% 的鱼粉使 SRT 饮食的成本增加了 9%，护理饮食的成本增加了 12%。