PALM KERNEL EXPELLER (PKE) EXTRACT AS A POTENTIAL FOOD FOR BRINE SHRIMP ARTEMIA BIOMASS PRODUCTION

Krishnnappriyaa Gopi¹ , Asmidar Mohamad² , Yeong Yik Sung^1*

¹Institute of Marine Biotechnology, University Malaysia Terengganu (UMT), 21300, Kuala Terengganu, Malaysia

²Institute of Tropical Aquaculture and Fisheries, University Malaysia Terengganu (UMT), 21300, Kuala Terengganu, Malaysia

*Corresponding author: kpriyaagopi@gmail.com

The brine shrimp is one of the most common life feed organisms used in aquaculture. Artemia may be fed at every stage of its life cycle, including cysts, nauplii, juveniles, and adults. Adult Artemia are utilised as live feed for a wide range of aquatic organisms, both marine and freshwater. They are nonselective filter feeders that graze on food particles ranging in size from 1 to 50µm. Apart from microalgae, agricultural by-products are known to be used as Artemia food. This study revealed that Palm Kernel Expeller (PKE), a by-product of the palm oil industry, might be a possible food source for Artemia. Feeding PKE extracts to newly hatched Artemia in a stagnant batch culture system enhanced development to adult stage measuring around 1 cm within 14 days of culture, a similar observation to those given microalgae cells. The nutritional properties of Artemia fed with PKE extracts revealed 63% of protein, 16% of moisture, 6% of lipid, 3% of fibre and 12% of carbohydrate. Based on the findings, PKE extract is a possible food for Artemia, and this application may be effective for substituting microalgae usage, lowering total culture costs, and simplifying the culture process.

Keywords: Brine shrimp; Artemia; Palm Kernel Expeller (PKE)

Seaweed and clay powder in diets improve growth and health performance of Tilapia

Vu Anh Tuan^1*, Marie Gallissot², Nguyen Van Minh³

¹Olmix Group Representative Office, 167 Luong Dinh Cua Street, Thu Duc Town, Ho Chi Minh City, Vietnam

²Olmix Group, ZA du Haut du Bois, 56580 Bréhand, France

³Institute of Aquaculture, Nha Trang University, 2 Nguyen Dinh Chieu Street, Nha Trang City, Vietnam

^*Corresponding author:  tuanvu@olmix.com

Two levels of seaweeds (Ulva spp. and Solieria chordalis) and clay powder were 0.1% and 0.2% to be incorporated in the diets of an experiment with 6 replicates on growth and health performance of juvenile Tilapia (Oreochromis niloticus) for 12 weeks. The experiment had 6 diets including a basal diet contains 20% fish meal (control 1), a basal diet contains 5% fish meal (control 2), treatment 1 is the control 1 and 0.1% of seaweed and clay powder; treatment 2 is the control 2 and 0.1% of seaweed and clay powder; treatment 3 is the control 1 and 0.2% of seaweed and clay powder; and treatment 4 is the control 2 and 0.2% of seaweed and clay powder. The 2 control diets were formulated to be iso-nitrogenous (32% CP) and iso-caloric (2,550 kcal DE/kg). Poultry meal was the main ingredient to replace fish meal. Seven hundred and twenty mono male tilapia (6.5 grams/fish) were randomly allocated to thirty-six glass 240L tanks, stocked at 20 fish/tank. Fish were fed three times a day at 3-5% body weight. Growth performance, feed efficiency, survival rate and hematological parameters were recorded for 12 weeks. Result showed that levels of the seaweed and clay powder improved the growth performance independently of fish meal inclusion. Supplementing the seaweed and clay powder into the feed significantly compensated the lower performance of fish fed diets with 5% fishmeal. The 5% fishmeal diet supplemented with 0.2% the seaweed and clay powder resulted in a better growth performance than the control diet with 20% fishmeal inclusion, thus compensating the 15% replacement of fishmeal with sustainable ingredients (P<0.001). A clear decreasing trend of FCR was observed when the seaweed and clay powder was added to the diet. Fish fed a diet with 5% fishmeal inclusion had a significantly lower survival rate. Particularly, the diet was supplemented with the seaweed and clay powder improved the survival rate. The health performance showed that a decrease of fish meal in the diet has a negative effect on the hematological parameters while they were significantly increased as the seaweed and clay powder supplementation. Therefore, it can be concluded that the seaweed and clay powder can improve growth and health performance at the high fish meal diets, or it can maintain these performances of fish were fed with the lower fish meal diets.

Keywords: macro algae, algae extract, montmorillonite, Nile tilapia, bentonite, seaweed, red algae, green algae

EFFECTS OF DIETARY METHIONINE LEVELS AND TEMPERATURES ON FEED INTAKE AND NEUROPEPTIDE EXPRESSIONS IN JUVENILE COBIA (Rachycentron canadum)

Minh V. Nguyen¹*, Linh P. Pham^1,2, A-E.O. Jordal², M. Espe³, L. Conceição⁴, M. Yúfera⁵, S. Engrola⁶, M.H. Le¹, I. Rønnestad²

¹Institute of Aquaculture, Nha Trang University, Nha Trang, Vietnam

²University of Bergen, Department of Biological Sciences, Bergen, Norway

³Institute of Marine Research, Bergen, Norway

⁴SPAROS Lda, Olhão, Portugal

⁵Instituto de Ciencias Marinas de Andalucía (ICMAN-CSIC), Puerto Real, Cádiz, Spain

⁶Centre of Marine Sciences of Algarve (CCMAR), University of Algarve, Faro, Portugal

*Corresponding author: minhnguyen@ntu.edu.vn

This study aims to explore the impact of dietary methionine concentrations combined with temperatures on feed intake (FI) and expressions of appetite neuropeptides (neuropeptide y, npy; agouti-related protein, agrp; cocaine- and amphetamine-regulated transcript, cart; and cholecystokinin, cck) and one receptor (melanocortin 4 receptor mc4r) in the brain of cobia.  The juvenile cobia (ca 3.7g body weight) were reared in two recirculation systems at control temperature (30°C) and elevated temperature (34°C) at the Center for Aquatic Animal Health and Breeding Studies (Nha Trang University, Vietnam). The fish were fed diets with different levels of methionine; deficient (M9; 9 g/kg), sufficient (M12; 12 g/kg) and surplus (M16, 16 g/kg) for 6 weeks (triplicate tanks per treatment). Results showed that cobia fed M9 diet had a lower FI at both temperatures. Further, there was a significant interaction between dietary methionine levels and temperature on FI, with a lower FI in cobia at 34°C compared to fish kept at 30°C and fed the M12 diet and M16 diets. Feed intake was correlated to brain mRNA expression levels of npy and agrp, while temperature significantly influenced the mRNA expression of agrp, cart, cck and mc4r. Expression of the orexigenic neuropeptide npy were consistently higher before the meal compared to after the meal for all diets and at both temperatures. At 30°C pre-feeding levels of npy correlated with both increased methionine levels as well as FI. The interaction between dietary methionine and temperature on levels of brain npy expression was significant (P<0.05). There was a higher brain expression of agrp, cart and cck in cobia at 34 °C compared to fish at 30 °C that was correlated with a lower FI. In summary, both feeding, temperature and/or dietary methionine levels affected the brain expression of npy and agrp, cart and cck suggesting that these neuropeptides are actively involved in adjusting feed intake to compensate towards changing energetic demands as well as metabolic adjustments due to variable availability of methionine at elevated temperature.

Keywords: feed intake, appetite, neuropeptide, cobia, dietary methionine

SUBSTITUTION OF FISHMEAL WITH BLACK SOLDIER FLY LARVAE MEAL IN HOVEN’S CARP Leptobarbus hoevenii

Sharifah Rahmah^1,2*, Hon Jung Liew²

¹Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, 21030 Kuala Nerus Terengganu

²Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, 21030 Kuala Nerus Terengganu

*Corresponding author: sharifah.rahmah@umt.edu.my

Black soldier fly larvae meal (BSFLM) has been receiving attention as an environmentally, socially, and economically sustainable alternative dietary protein source in aquafeed formulations due to the global scarcity of fishmeal (FM). The subsequent rise in the price of (FM) is considered unfeasible to the sustainability of aquafeed production. Hence, the current study aims to evaluate the effects of substituting fishmeal protein with black soldier fly larvae meal protein on the growth performance and bioenergy mobilization of the high-priced hoven’s carp, Leptobarbus hoeveni. Five experimental diets were formulated and prepared to contain 0, 25, 50, 75 and 100% of protein substitution from FM with BSFLM. After 60 days of feeding trial, weight gain, specific growth rate, feed conversion ratio, protein conversion ratio and survival were not significantly affected. During the experimental duration, muscle protein and lipid contents were not significantly different among treatments. Nevertheless, the muscle glycogen tends to reduce as the substitution of BSFLM increases. Concurrently, the liver protein was similar in fish fed all diets but was slightly higher at 75% without significant difference. Liver lipid and glycogen contents increased as the BSFLM substitution level increased but slightly dropped at total FM protein replacement. In summary, the total substitution of FM protein with BSFLM did not compromise the growth performance of hoven’s carp but the bioenergy mobilization suggests different preferences of energy usage from the muscle and liver to fulfil the metabolic requirement of hoven’s carp

Keywords: Alternative Protein Source, Aquafeed, Bioenergy mobilization, Feed Efficiency, Growth Performance, Sultan Fish

EFFECTS OF NATURAL POLYPHENOL ANTIOXIDANT (CABANIN® CSD) ON GROWTH PERFORMANCE AND STRESS RESISTANCE OF NILE TILAPIA (Oreochromis niloticus)

Tuan, V. V^1*., Karsten, C. K²., Binh, V. T. T³., and Hung, L.T¹

¹Faculty of Fisheries, Nong Lam University, Ho Chi Minh city, Vietnam

²R2 Agro A/S, Mimersvej 1, DK-8722 Hedensted, Denmark

*Corresponding author: vovantuan@hcmuaf.edu.vn

This study was conducted to investigate the effects of Cabanin®CSD supplemented diets on the growth performance and stress resistance of Nile tilapia (Oreochromis niloticus). Fish were fed experimental diets containing different levels of vitamin C, vitamin E and Cabanin® CSD for 10 weeks. After the trial, specific growth rate, feed utilization and survival rate  were observed. Blood biochemical parameters consisted of superoxide dismutase activity, Malone dialdehyde, cortisol, and glucose were measured. Malone dialdehyde in the flesh meat of tilapia was also evaluated during refrigerated storage. The fish was then challenged with 60 mg/l ammonia for 168h. Survival rate and biochemical parameters of blood (glucose and cortisol) were recorded after exposure to ammonia. The results showed that growth performance of tilapia were significantly improved by Cabanin® CSD supplementation (p<0.05), while survival rates were similar between control and Cabanin® CSD supplemented diet groups. Superoxide dismutase activity and malone dialdehyde level in blood  serum were significantly difference between control and Cabanin® CSD supplemented diet groups (p<0.05). Malone dialdehyde level was significantly higher in the control group in comparison with Cabanin® supplemented groups at day 1 and day 7 of refrigerated storage (p<0.05). In the ammonia challenge test, the highest survival rate was observed in the Cabanin® CSD supplemented diet groups compared to the control group. The fish serum glucose and cortisol levels increased in all the Cabanin® CSD supplemented diet groups. In general, dietary 0.2% Cabanin® CSD could exert beneficial effects on growth performance, antioxidant capacity, and biochemical activity of tilapia under ammonia stress.

Key words: Cabanin® CSD, tilapia, growth performance, superoxide dismutase, Malone dialdehyde, glucose, cortisol.