Linseed protein concentrate as alternative to fishmeal in diets for silver catfish, Rhamdia quelen

Abstract

Abstract A 60‐day feeding trial was conducted to evaluate the efficiency of the substitution of fishmeal (FM) with linseed protein concentrate (LPC) in the diet of silver catfish, Rhamdia quelen (6.13 g). Five isonitrogenous and isoenergetic experimental diets were formulated to replace 0, 10, 20, 30, or 40% of FM with LPC, and silver catfish were fed these diets to apparent satiation. LPC had a lower protein content compared to FM, but in vitro results showed higher protein digestibility of LPC as compared to fishmeal. There were no significant differences (p > .05) in growth, digestive somatic index, and intestinal quotient in the groups receiving LPC diets. The activity of the digestive enzymes did not differ among treatments, except for chymotrypsin, which was higher (p < .05) in the 30 and 40% LPC treatment groups. These results show that LPC protein can replace up to 40% of FM in silver catfish diets without adverse effects on growth performance.

Keywords

• digestive enzyme activity
• growth
• linseed protein concentrate
• Linum uistatissimum L
• nutritional composition
• Rhamdia quelen