Title: Effect and interaction of trout strain (Oncorhynchus mykiss) and diet type on growth and nutrient retention Authors
Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 7, 2011
Publication Date: January 4, 2012
Citation: Overturf, K.E., Barrows, F., Hardy, R. 2012. Effect and interaction of trout strain (Oncorhynchus mykiss) and diet type on growth and nutrient retention. Aquaculture Research. 12:1–8. doi:10.1111/j.1365-2109.2011.03065.x. Interpretive Summary: Aquaculture production is expanding significantly around the world. One of the major impediments to both current and developing aquaculture production is the availability of sustainable sources of feed. Sustainable feeds have been developed but growth on these feeds is much lower than growth on traditional fishmeal based diets. A strain of rainbow trout was developed by the USDA-ARS in Hagerman, Idaho by selecting for growth and utilization of a sustainable plant-based feed. The ARS strain was compared against two other strains of trout for growth on a traditional fishmeal feed and on a sustainable plant-based feed. The selected ARS strain outgrew the other two strains on the plant-based feed and the selected strains was found to grow better on the plant-based feed compared to the fishmeal feed.
Technical Abstract: Eight strains of rainbow trout were introgressed to develop a single strain (H-ARS) that was selected for faster growth when fed a fishmeal free, plant-based diet (Selection Diet). For four generations, families from these crosses were fed the Selection Diet and selected for increased weight gain. Growth and nutrient retention was compared among H-ARS and two parental strains the House Creek (HC) and Fish Lake (FL) fed either a fish meal or Selection diet for 12 weeks. There was a significant effect of strain (P<.01) but not diet on weight gain, and a significant interaction of strain by diet (P<.05). The H-ARS trout gained more weight averaged across diet (991% of initial wt.) than the HC (924%) or FL trout (483%). The FL trout fed the fish meal diet gained more weight than FL trout fed the Selection diet (510 % vs 456 %). Conversely, H-ARS trout fed the plant based diet gained more weight than those fed the fish meal diet (1009% vs 974%). HC trout had similar weight gain fed either diet (922% vs 926%). A significant effect of strain on protein retention (P<.01) was observed, along with a significant strain by diet interaction (P<.02).