Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America.
Department of Fisheries Management, Bangladesh Agricultural University, Mymensingh, Bangladesh.
PLoS One. 2020 Jul 23;15(7):e0236100. doi: 10.1371/journal.pone.0236100. eCollection 2020.
Feed constitutes 50-70% of total production costs of tilapia, one of the most widely cultured finfishes in the world. We evaluated reduced-feeding strategies for improving production efficiency of Nile tilapia (Oreochromis niloticus). In a 12-week pond trial, fish were fed daily, every other day, every third day, or not at all. Ponds were fertilized to enhance natural foods. In a fifth group fish were fed daily without pond fertilization. Fish fed daily with or without pond fertilization and fish fed every other day had higher specific growth rates, survivability, and net production than the other two treatments. Fish feed efficiency and benefit to cost ratio was highest for treatments fed in a pulsatile manner (i.e. fed every other day or every third day) with fish fed on alternate days providing the best net return among all groups. Fish fed on alternate days had more moderate gene expression levels of intestinal nutrient transporters which may allow for a more balanced and efficient nutrient uptake. Fecal microbe analyses identified 145 families of prokaryotic and 132 genera of eukaryotic organisms in tilapia. The highest diversity of prokaryotes was found in fish fed either every other day or daily in fertilized ponds and the highest diversity of eukaryotes was found in fish fed every other day. These studies indicate feeding Nile tilapia on alternate days along with weekly pond fertilization has no deleterious effects on growth, survivability, or production versus daily feeding regimes, but enhances feed efficiency by 76% and provides the greatest net return on investments. Our studies also suggest for the first time that combining alternate-day feeding with pond fertilization produces the greatest microbial biodiversity in the intestine that could contribute to enhanced feed efficiency and overall health of tilapia.
饲料占罗非鱼（世界上养殖最广泛的鱼类之一）总成本的 50-70%。我们评估了减少投喂策略，以提高尼罗罗非鱼（Oreochromis niloticus）的生产效率。在为期 12 周的池塘试验中，鱼每天、隔天、每三天或不投喂。池塘施肥以增加天然食物。在第五组中，鱼每天投喂但不施肥。与不施肥或每天投喂的鱼相比，每天或隔天投喂的鱼具有更高的特定生长率、存活率和净产量。以脉冲方式投喂（即隔天或每三天投喂一次）的处理方式的饲料效率和成本效益比最高，其中隔天投喂的鱼在所有组中提供了最高的净回报。隔天投喂的鱼肠道营养转运蛋白的基因表达水平更为适中，这可能允许更平衡和高效的营养吸收。对罗非鱼粪便微生物的分析在肠道中共鉴定出 145 个原核生物家族和 132 个真核生物属。在施肥池塘中，每天或隔天投喂的鱼中发现的原核生物多样性最高，而在隔天投喂的鱼中发现的真核生物多样性最高。这些研究表明，与每天投喂相比，每隔一天投喂尼罗罗非鱼并每周对池塘施肥不会对生长、存活率或生产产生不利影响，但可将饲料效率提高 76%，并提供最大的投资回报。我们的研究还首次表明，将隔天投喂与池塘施肥相结合可在肠道中产生最大的微生物多样性，这可能有助于提高罗非鱼的饲料效率和整体健康水平。
