Substitution effect of Undaria pinnatifida with citrus ( Citrus unshiu , Marcovitch) peel by‐product in feed on the growth, body composition and air exposure stressor of juvenile abalone ( Haliotis discus , Reeve 1846)

Abstract

Substitution effect of Undaria pinnatifida with citrus peel by‐product (CPB) on growth, body composition and air exposure stressor of abalone was determined. A total of 1,080 abalone were distributed into 18 net cages. Five formulated diets were prepared in triplicate. The CPB0 diet contained 200 g/kg U. pinnatifida. The 250, 500, 750 and 1,000 g/kg U. pinnatifida were substituted with the equal amount of CPB, referred to as the CPB250, CPB500, CPB750 and CPB1000 diets, respectively. Finally, dry U. pinnatifida was prepared. Abalone were fed for 16 weeks and then subjected to air exposure stressor for 24 hr. The cumulative mortality of abalone was monitored for the following 4 days after 24‐hr air exposure. Survival, weight gain and specific growth rate (SGR) of abalone fed all formulated diets were greater than those of abalone fed the U. pinnatifida. The greatest weight gain and SGR were achieved in abalone fed the CPB500 diet. The chemical composition of the soft body of abalone was not affected by the experimental diets. Higher cumulative mortality was observed in abalone fed the CPB0 and dry U. pinnatifida at 16 hr after 24‐hr air exposure compared to abalone fed all other diets. In conclusion, U. pinnatifida could be completely substituted with CPB in abalone feed.

Substitution effect of broccoli (Brassica oleracea var. italica) by‐product for Saccharina japonica in feeds on growth, carcass chemical composition, and air exposure resistance of abalone (Haliotis discus, Reeve 1846)

“…This could be one of reasons why abalone fed all formulated diets outperformed abalone fed S. japonica in the present investigation. This result is consistent with previous studies by Yun et al (2020) and demonstrating that abalone (H. discus) fed nutrition-balanced formulated diets grew better than abalone fed single MA because of the high water stability in the former.…”

“…Hu et al (2012) also demonstrated that administration of leaves as well as stems of broccoli improved superoxide peroxidase and catalase activities, and total antioxidant capability of breast muscle in broiler chickens. Similarly, Jeong et al (2020) and Yun et al (2020) also claimed that dietary substitution of MA with some agricultural by-products containing several bioactive compounds increased the survival of abalone (H. discus) after being exposed to air for a period of time.…”

“…However, the disadvantages of using MA as abalone's primary food source include their insufficient supply in certain seasons, seasonal variations in nutrient compositions, and undesirable introduction of diseases and pests into culture systems (Bautista‐Teruel et al, 2011; Garcia‐Esquivel & Felbeck, 2009). Additionally, MA remains low in protein (amino acids) and lipid (fatty acids) content, resulting in poor growth performance of abalone (Bansemer et al, 2016; Dang et al, 2011; Mai et al, 1994; Viana et al, 1993; Yun et al, 2020). Nevertheless, relatively high amounts (150–300 g/kg) of MA are generally employed in commercially formulated abalone feeds in Korea (Dai & Cho, 2022; O'Mahoney et al, 2014).…”