Aquaculture America 2024

February 18 - 21, 2024

San Antonio, Texas

NUTRITIONAL VALUE OF AN AQUEOUS-PROCESSED CANOLA PROTEIN CONCENTRATE FOR ATLANTIC SALMON: DIGESTIBILITY AND GROWTH PERFORMANCE

 Van Pham Thi Ha To* ,  André Dumas, Ivan Tankovski, John Brennan, Jason Hargreaves, David Dzisiak

The Center for Aquaculture Technologies, Souris, PE, C0A 2B0, Canada

 Email: vto@aquatechcenter.com

 



 Canola, the  world’s  second  most produced  oilseed crop , has a great potential to be a major protein ingredient  in aquafeeds due to its  high nutritional values and good amino acid profile. Recent advances in aqueous processing have enabled  the scalable production of environmentally friendly and nutrient-rich canola protein concentrate (CPC : 75.8% crude protein, 4.4% crude lipid). The objectives of this study were to  1)  determine  the nutrient digestibility of CPC; and 2)  evaluate  the effects  dietary inclusion levels of CPC on Atlantic salmon growth performance, feed  efficiency, nutrient utilization, gut histology and fillet color.

Two digestibility trials using settling column and stripping method  were conducted  for  juvenile (57.3 ± 6.7 g) and post-s molt ( 227.7 ± 4.1 g) Atlantic salmon, respectively .  The results  demonstrated that the nutrients in CPC were well digested by Atlantic salmon ,  with  mean apparent digestibility coefficients for  crude protein, crude lipid and essential amino acids of 87.1, 93.3 and 81.5-97.0%  for juvenile fish  and 95.7, 90.9 and 93.9-98.0%  for post-smolt fish , respectively . In a  long-term growth study, eight experimental diets containing 0% (Diets A, E), 10% (Diets B, F), 15% (Diets C, G), and 20% (Diets D, H) CPC were formulated to mimic commercial  salmon  feeds in different geographies:  Americas-style diets (A through D)  contained processed animal protein (PAP) , whereas Europe -style diets (E through H) did not include PAP. Each diet was randomly allocated to triplicate groups of  33  fish (228.0 ± 4.9 g)  per 750-L tank. F ish were hand-fed to  apparent satiation for 168 days . The result  showed  that  thermal-unit growth coefficient  and feed intake were  comparable  between treatments (Table 1). 10% CPC  inclusion  was optimal for feed conversion ratio .  There was no significant difference in final whole-body composition or nutrient retention among treatments . Increased dietary  CPC  inclusion from 0-20% resulted in positive associations with intestinal villi length and  fillet redness value . In conclusion , CPC is a highly digestible nutrient-dense  ingredient that can  be safely included in Atlantic salmon diets up to  at least 20%.