Effects of processing full‐fat soya beans and fish trim for sustainable sablefishAnoplopoma fimbriafeeds

Abstract

To quantify the efficacy and cost of different soya protein ingredients, heated soya beans (HSB) and underprocessed (SB) full-fat soya beans (FFSB), soya protein concentrate (SPC) and trim waste from Pacific whiting (Merluccius productus) were incorporated into feeds for the cold water marine sablefish (Anoplopoma fimbria). Feed ingredients for this study were processed using an experimental heated ball mill with demonstrated potential as an affordable process for rural or small-scale feed production. The three feed treatments were formulated with equal amounts of soya protein and Pacific whiting process trim. The three feed treatments contained 46% protein and 18% lipid as dry matter. Three 480-L tanks of 10 fish were used to evaluate each of the three feed treatments. Fish were fed to satiation every 2 days for 8 weeks. Weight gain of the treatment groups ranged between 56% and 105% over the course of the study. Fish growth was significantly better among fish receiving the feeds containing HSB and SPC than a feed containing SB. At the conclusion of the study, histomorphologic evaluations of the distal intestines of final fish were conducted. Varying levels of inflammation were measured for all three treatments. Fisher's exact test showed a significant reduction in mononuclear cell infiltration among fish fed heat-treated full-fat soya beans vs those receiving underprocessed full-fat soya beans. Fish receiving HSB feed had significantly lower intestinal inflammation than SB fish. Based on our results, cost savings of $ 0.253/kg were calculated for the HSB feed over the SPC feed. K E Y W O R D Scost, full-fat soya beans, histomorphologic evaluation, Sablefish

Sablefish (Anoplopoma fimbra Pallas, 1814) plasma biochemistry and hematology reference intervals including blood cell morphology

“…The fish used in this study received a commercial diet at 1% of their body weight distributed over at least two feeding events per day. Recent studies recommend feeding sablefish to satiation once every other day to allow for adequate feed conversion and consistent intake of the feed [ 42 , 43 ]. Reduced feed intake has been observed after four days of daily feeding, attributed to a prolonged gastrointestinal passage in this species [ 42 ] (and personal communication with Ron Johnson).…”

Sablefish (Anoplopoma fimbraPallas, 1814) plasma biochemistry and hematology reference intervals including blood cell morphology

“…The fish used in this study received a commercial diet at 1% of their body weight distributed over at least two feeding events per day. Recent studies recommend feeding sablefish to satiation once every other day to allow for adequate feed conversion and consistent intake of the feed (37,38). Reduced feed intake has been observed after four days of daily feeding, attributed to a prolonged gastrointestinal passage in this species (37) (and personal communication with Ron Johnson).…”

Status of sablefish, Anoplopoma fimbria, aquaculture

“…in alternative feeds for sablefish. Using heated ball mill processing, Nicklason et al (2020) found sablefish readily accept and grow well on a diet containing approximately 20% full fat soybeans after processing with wet heat.…”

“…Results indicate that properly processed full fat soybeans perform as well as more expensive soybean protein concentrates for this marine species and that sablefish may be tolerant to some anti-nutritional biomolecules (e.g., oligosaccharides and saponins) found in full fat soybeans that reduce feed performance in other cultured species, such as Atlantic salmon. An economic analysis of feed costs revealed coprocessing of fish trim with full fat soybeans shows great potential as an affordable process for rural or small-scale feed production for sablefish (Nicklason et al, 2020).…”