Feed trials in Canada
The purpose of this study was to verify whether farmed trout (brook trout, rainbow trout and Arctic char) fed high-energy Danish feeds that meet Danish environmental standards and based on a Danish nutritional strategy had a better feed conversion ratio and fewer environmental impacts, particularly in terms of phosphorus discharges, compared both to conventional feeds currently used by commercial fish farmers in Quebec and Canada and to newly developed Canadian feeds.
To meet this objective, feed trials were organized on a small scale under controlled laboratory conditions and on a large scale under normal commercial farm conditions. The main finding following analysis of the feeds used during the trials was that some Danish feeds contained more phosphorus than they should (up to 50% more). The trials themselves indicated that the zootechnical performance of the Danish feeds and new Canadian feeds was higher than the performance of conventional Canadian feeds. However, because the phosphorus contents were higher than the limits established under Danish regulations (for small-pellet Danish feeds), this reduced the potential benefits in terms of environmental performance. In terms of feed conversion ratios (FCRs), fish fed the Danish feeds obtained lower FCRs than fish fed new Canadian feeds and these were lower than the FCRs of fish fed conventional Canadian feeds. The study conducted at the Alma Aquaculture Research Station in Ontario also revealed that when trout were fed high-energy, low-phosphorus feeds, there was a significant reduction in the feed conversion ratio and a significant decrease in total phosphorus discharges.
2004 - 2005
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