Effects of feed processing conditions and acid salts on nutrient digestibility and physical quality of soy-based diets for Atlantic salmon (Salmo salar)

Abstract

Two experiments were conducted to investigate effects of feed processing conditions and potassium diformate (KDF) supplementation on apparent digestibility of nutrients in Atlantic salmon (Salmo salar) and physical quality of extruded feed. In Exp. 1, diets with raw or expander pretreated full-fat soybean meal (FFSBM) at 100 or 120°C were extruded at 110°C. Expander pretreatment significantly (P < 0.05) improved the digestibility of arginine, glutamine and tyrosine in Atlantic salmon. The higher digestibility of expander pretreated FFSBM was confirmed in mink (Mustela vison). In Exp. 2, diets with defatted soybean meal (SBM) were extruded at 110, 130 or 150°C. The results showed that increasing extrusion temperatures significantly (P < 0.05) improved the digestibility of most major nutrients and amino acids in Atlantic salmon. In general, KDF supplementation to FFSBM and SBM diets did not affect digestibility of nutrients in Atlantic salmon or mink. Expander pretreatment and increasing extrusion temperatures increased pellet expansion, while KDF supplementation reduced pellet expansion.

Effects of dietary moisture content of extruded diets on physical feed quality and nutritional response in Atlantic salmon (Salmo salar)

“…Hardness of pellets is positively associated with pellet diameter (Abdollahi et al, 2012, Kaliyan & Vance Morey, 2009). The higher hardness of pellets used in the present experiment may thus be explained with the larger diameter of the pellets compared to other experiments (Aas et al, 2011b, Morken et al, 2011, Morken et al, 2012. The high hardness of the feeds used in the present experiment may have interfered with feed intake, restricting the realization of growth potential.…”

“…In measurement of particle size distribution, large variation was also noted for D96 and was due to one sample with very large particles. However, the variation among the feeds were modest, ranging between 33.2 N to 52.3 N. Besides, the hardness values of the feeds used in the present experiment were high compared to other experiments (Aas et al, 2011b, Morken et al, 2011, Morken et al, 2012. Hardness of pellets is positively associated with pellet diameter (Abdollahi et al, 2012, Kaliyan & Vance Morey, 2009).…”

Organic acid salts, protease and their combination in fish meal‐free diets improved growth, nutrient retention and digestibility of tilapia ( Oreochromis niloticus × O. aureus )

“…In the same way, Ng, Koh, Sudesh, and Siti‐Zahrah () and Morken et al. () also did not observe any improvement in nutrients digestibility in tilapia and Atlantic salmon, respectively, when supplemented with dietary potassium diformate. The present study showed that weight gain was improved and FCR was decreased (Table ), but the nutrient digestibility and nutrient retention were only numerically improved by the supplementation of OAB (Tables and ).…”

The utilization and mode of action of organic acids in the feeds of cultured aquatic animals

“…In contrast, Morken et al . () noted no significant interactions between KDF and extrusion temperature with respect to both nutrient digestibility and physical quality of extruded feeds when 12 g kg −1 KDF was supplemented into diets containing soya bean meal for Atlantic salmon. They attributed the inconsistent findings to differences in the concentrations of organic acids, animal species, diet composition as well as the culture conditions.…”