Evaluation of two types of ingredients from marine fish rest raw materials in broiler diets: effects on live performance and meat lipid composition

The current study investigated the effect of incorporating two ingredients derived from different types of marine fish rest raw materials in the diet of broiler chickens on live performance, carcass yield, muscle fatty acid (FA) composition, lipid peroxidation products, and blood metabolites. A total of ninety (n = 90), one-day-old Cobb chicks were fed a corn-soybean meal-based diet with no marine rest raw material (Control), 5% deboned Pacific hake meal (Diet 1), or 5% Pacific surimi washwater meal (Diet 2) for 42 d (30 birds per treatment kept in 6 replicate pens with 5 chicks per pen). For bird performance (feed consumption, weight gain), each replicate pen was considered as the experimental unit. For determining yield, blood metabolites, and lipid analysis, one bird collected from each replicate is considered as the experimental unit. Bodyweight gain and feed:gain were determined at the starter (1–10), grower (11–21), and finisher (22–42) phases. For all response variables, the effects of Control vs. Diet 1 and Diet 2 were compared separately using analysis of variance. P values were considered significant at ≤0.05. No difference was observed in the body weight gain and feed:gain at day 10 (P > 0.05). At day 21, Diet 1 and Diet 2 birds were higher in body weight than Control (P < 0.05). At day 42, Diet 1 birds were highest in body weight (3,018 g) when compared to Control (2,728 g) (P < 0.05) and was not different from Diet 2 (2,912 g) (P > 0.05). Overall, feed:gain was lowest in Diet 2 (1.52) (P < 0.05) and was not different from Diet 1. A 2 to 5-fold increase in n-3 FA was observed in the breast and thigh muscle of Diet 1 and Diet 2 compared to Control (P < 0.05). Docosahexaenoic acid (DHA, 22:6 n-3) was the major long chain FA in the breast and thigh muscle and addition of marine rest raw material led to >10-fold increase in the breast and thigh muscle DHA in Diet 1 and Diet 2 when compared to Control (P < 0.05). The total lipid content of thigh muscle was lower in Diet 1 and Diet 2 compared to Control (P < 0.05). No difference was observed in the total lipid content of breast muscle (P > 0.05). The relative organ weight and yield of breast and thigh muscles were not different among the three treatments (P > 0.05). No difference was observed in moisture and cholesterol content in breast and thigh muscles (P > 0.05). Blood cholesterol was lower in Diet 1 than Control (P < 0.05). Lipid peroxidation products measured as thiobarbituric acid reactive substances (TBARS) were lower in the breast muscle of Diet 1 and Diet 2 compared to Control (P < 0.05). However, no effect of diet on thigh muscle TBARS was observed (P > 0.05). As consumer demands for n-3 FA-rich poultry products are on the rise, products derived from marine rest raw materials may serve as feed supplement that could be used in broiler chicken diets for enriching edible tissues with n-3 FA while increasing bird live performance and promoting ecological poultry production.