Soft-dry Pellets Research Articles

Optimum Levels of Protein and Lipid in a Newly Developed Soft-dry Pellet for Yellowtail, Seriola quinqueradiata

Optimum Levels of Protein and Lipid in a Newly Developed Soft-dry Pellet for Yellowtail, Seriola quinqueradiata

Utilization of alternative protein sources as substitute for fish meal in a newly developed soft-dry pellet for yellowtail

Utilization of alternative protein sources as substitute for fish meal in a newly developed soft-dry pellet for yellowtail

Practical Culture of Yellowtail with a Newly-developed Soft-dry Pellet

Practical Culture of Yellowtail with a Newly-developed Soft-dry Pellet

Combined use of Alternative Protein Sources as a Partial Replacement for Fish Meal in a Newly Developed Soft-Dry Pellet for Yellowtail

Combined use of Alternative Protein Sources as a Partial Replacement for Fish Meal in a Newly Developed Soft-Dry Pellet for Yellowtail

Broodstock nutrition research on marine finfish in Japan

Broodstock diet formulations are essential for the development of marine fish breeding and propagation. Japanese research has mainly focused on red sea bream ( Pagrus major), yellowtail ( Seriola quinqueradiata), the Japanese flounder ( Paralichthys olivaceus) and striped jack ( Pseudocaranx dentex), and indicated that the required quantities of essential dietary components may vary according to species. The more recent work carried out on yellowtail and striped jack consolidated the trends already observed in red sea bream. In yellowtail, soft-dry pellets were used and astaxanthin was found to be the determining factor for good egg quality, when supplemented at around 30 mg/kg. Paprika powder supplementation that provided about 30 mg/kg paprika esters further improved the spawning performance of yellowtail in terms of egg production, egg quality and larval survival whereas squid meal inclusion also showed potential as an effective ingredient. Work on the development of dry pellets for striped jack broodstock revealed that egg production and quality were affected by separate nutrients. Even though striped jack eggs do not contain carotenoids, dietary astaxanthin, added at 10 mg/kg to the diet, increased fecundity whereas egg quality was improved through the replacement of half the fish meal with squid meal. The combination of these two ingredients in dry pellets produced a spawning performance that matched the widely used raw fish mix. Fatty acids, especially n−3 highly unsaturated fatty acid (HUFA) in fertilized eggs, were derived from dietary lipids in all the species studied. From the present information, it is evident that optimal levels of astaxanthin or paprika esters that have high oxygen quenching abilities, squid meal and n−3 HUFA play an important role in gonadal development of different marine fish. These dietary components should be utilised for the development of wholesome dry pellets for marine broodstock.

Supplementation of paprika as a carotenoid source in soft-dry pellets for broodstock yellowtail Seriola quinqueradiata (Temminck & Schlegel)

This study was carried out to investigate whether readily available paprika can replace astaxanthin as a source of carotenoids in soft-dry pellets for broodstock yellowtail Seriola quinqueradiata (Temminck & Schlegel). Five months prior to spawning, 120 fish of average body weight (BW) 6.2 ± 1.5 kg were divided into three groups and fed basal soft-dry pellets (SDP), SDP supplemented with 30 mg/kg astaxanthin (a-SDP), or SDP supplemented with 2% paprika (p-SDP). Feeding was carried out in floating net cages and two spawning trials were performed. Fish were selected (five male and five female per group per trial), injected with human chorionic gonadotropin (600 IU kg−1 fish) and transferred to 100 m3 indoor concrete tanks for spawning. In trial 1, egg production during the first day of spawning was highest for the p-SDP group, followed by the a-SDP and SDP groups. For the p-SDP, a-SDP and SDP groups, fertilization rates were 76.0%, 69.7% and 61.9% and hatching rates were 75.2%, 63.9% and 59.4%, respectively. In trial 2, fertilization rates were 80.9%, 78.0% and 86.8% and hatching rates followed the same trend as in trial 1, at 61.8%, 52.9% and 37.2%, respectively. Moreover, larvae of the p-SDP groups showed better survival at day 3 after hatching. Apart from the darker yellow colour of fertilized eggs of the astaxanthin or paprika supplemented diet groups, analysis showed that carotenoids from paprika were successfully incorporated into the eggs, mainly as zeaxanthin and lutein. Paprika supplementation did not affect the fatty acid and lipid class profiles of eggs and unfed larvae. These results indicate that paprika supplementation in soft-dry pellets is effective for good quality egg production in yellowtail.

Quality evaluation of different types of non-fish meal diets for yellowtail

SUMMARY: Two feeding experiments were conducted to evaluate the feed quality of non-fish meal diets having the same protein ingredient composition but prepared as different types, and to determine the supplemental effect of crystalline essential amino acids (EAA) on feed utilization by young yellowtail, Seriola quinqueradiata. Non-fish meal diets formulated with soy protein concentrate, defatted soybean meal, corn gluten meal, meat meal, and krill meal were prepared as either soft dry pellets (SDP) or extruded pellets (EP) by using a large- or a small-sized twin screw extruder under different preparation conditions; or as a single moist pellet (SMP), each with and without EAA mixtures. Commercial yellowtail SDP was used as the control diet. Fish weighing 134 g and 237 g on average were reared with the experimental diets, for 93 (net cages) and 44 (aquariums) days, respectively. The fish fed both the control and test diets were found to have a good appetite. Growth rate and feed gain ratio were highest in the control diet group. The physiological condition of fish fed the control diet was evaluated as superior compared to those on the non-fish meal diets. Among the non-fish meal diet groups, the best performances were obtained for fish fed the SDP type diet with EAA supplement, and performance parameters excelled in the order of SDP, EP and SMP both among the diets with and without supplemental EAA. This suggests that the nutritional quality of non-fish meal diet was affected by the diet preparation method. It also indicates that supplementation of EAA could improve the quality of non-fish meal diets, irrespective of the diet type, probably as a result from the enhancement of feed protein utilization.

Energy and protein requirements of yellowtail during winter season

This study was conducted to determine the energy and protein requirements of yellowtail during the winter season (12.8-16.5°C) when they have a comparatively low feeding activity. The feeding experiment was conducted in net cages (3×3×3 m) located at Mie Prefecture, Japan. The fish (745-758 g) were split into six groups: the first five were fed to satiation, and at 70, 50, 30, and 10% of satiation levels, respectively, while the sixth group was starved. The experimental diets were commercial soft-dry pellets (SDP) with known digestible energy (DE) and protein (DP) values. The groups were fed three times a week for 4 weeks. The growth rate was highest in the satiation group and decreased with decreasing feeding levels. The DE and DP requirements were 42.1 kcal and 3.3g/kg BW/day for maximum growth and 14.7 kcal and 1.1 g/kg BW/day for maintenance of body weight. The DE and DP requirements for the maintenance of body energy content were estimated to be 19.6 kcal and 1.5 g/kg BW/day, respectively.

Effect of Krill Meal Supplementation in Soft-dry Pellets on Spawning and Quality of Egg of Yellowtail

Effect of Krill Meal Supplementation in Soft-dry Pellets on Spawning and Quality of Egg of Yellowtail

市販ソフトドライペレットを給餌したブリの採卵結果

Yellowtail Seriola quinqueradiata broodstocks, captured by set-net fishery and reared on raw fish for one and a half years, were fed frozen raw fish (RF group), moist pellets (MP group), or soft dry pellets (SDP group) for 6 months before egg collection. The MP group received a 1:1 diet mixture consisting of a formula feed prescribed by the National Research Institute of Aquaculture and raw fish, whereas the SDP group was fed a commercial soft dry pellet. After 6 months the fifh in each net-cage were injected with hormone (HCG) to induce spawning, and eggs were collected from each broodstock either after induced spawning or by strip spawning of adults followed by the dry method of insemination. Parameters of the SDP group such as number of eggs per spawner, fertilization rate, hatching rate, and survival rate of the larvae were compared with those of the RF and MP groups. The success of egg collection from the SDP group was as good as that from the MP group, and those from the SDP and MP groups were superior to that from the RF group. These results clearly indicated that both DP and MP were efficacious for broodstock management of yellowtail and their egg collection.

Effect of Extrusion Processing on the Utilization of Soybean Meal Diets for Rainbow Trout.

The effect of extrusion processing by a twin screw extruder on the nutrient utilization, and the availability of defatted soybean meal (SBM) as partial protein source were studied with rainbow trout of about 4-5g. In Expt. I, fish were fed the control and 30% SBM diets with and without extrusion processing for 6 weeks. In Expt. II, fish were fed ordinary steamed dry pellets (DP) containing 30% SBM or 30% extruded SBM (ExSBM) as a partial substitute for fish meal, and extruded soft-dry pellets (SDP) with 30% SBM for 8 weeks.Expt. I: There was no marked difference in growth or feed efficiency between the control and 30% SBM diets. Their dietary values and growth rate were not significantly improved by the extrusion, although the digestibility of starch was markedly elevated. The digestibility of dietary protein was not influenced by extrusion processing, ranging between 88 to 91%. Expt. II: Of the 30% SBM diets, SDP with a higher energy content produced higher growth, PER, protein, and energy retention than DP. Feed consumption was slightly lower in SDP with the higher energy level, leading to improved feed efficiency. Replacement of 30% SBM with the same level of ExSBM did not result in any nutritional improvement of DP.

Potential of Soybean Meal as a Protein Source in Extruded Pellets for Rainbow Trout.

The potential of defatted soybean meal (SBM) as a protein source in high energy diets (extruded soft-dry pellets, SDP) was studied with rainbow trout of about 5g. The SDP contained respectively 0, 20, 30, 40, and 50% SBM, or 25% SBM plus 15% corn gluten meal (CGM) as a substitute for fish meal. The digestibility of SBM nutrients in SDP was determined using a reference diet and test diets which were formulated to contain both the reference diet and SBM in a ratio of 70:30, 60:40, and 50:50, respectively.The combination of 25% SBM with 15% CGM produced the best growth, while inclusion of SBM up to 50% did not reduce growth or protein utilization efficiency compared to the control diet. However, feed efficiency was slightly lower in SBM supplemental diets caused by the undigestible carbohydrate portion of SBM. The digestibility of protein, starch, and energy of SBM was 91, 54, and 80%, respectively, rather unaffected by the SBM levels in the formulation.It was concluded that SBM can be included up to 50% in SDP, replacing up to 91% of fish meal, supporting excellent growth and feed performance. A combination of 25% SBM and 15% CGM was confirmed to be an effective alternative protein source for rainbow trout.

Utilization of Soybean Meal as a Protein Source in a Newly Developed Soft-dry Pellet for Yellowtail.

The availability of defatted soybean meal (SBM) as a substitute for fish meal in a newly de-veloped soft-dry pellet (SDP) was evaluated in juvenile (160g on average) and adult (1, 200g on average) yellowtail by feeding SDP containing 0-30% SBM for 74 and 143 days, respectively. Palatability and acceptability in both sizes of fish were not affected by the inclusion of SBM in SDP, while growth and feed gain ratio were slightly reduced at higher SBM levels, probably due to the nitrogenous and caloric imbalance of the diets. There were no marked differences in proximate composition and rheological properties of muscle together with hemochemical par-ameters in either juvenile or adult yellowtail fed on SDP containing 0-30% SBM. Digestibility of crude protein in the experimental SDP and SBM was about 85% regardless of dietary SBM levels, while that of crude starch was reduced by the elevation of dietary SBM levels. The results of the present study have shown that SBM can be included in the SDP up to 30% as a substitute for fish meal, although elevation of a protein or energy level will be required to obtain feed performances comparable to a fish meal diet.

Use of Soybean Meal as a Substitute for Fish Meal in a Newly Developed Soft-Dry Pellet for Yellowtail.

The availability of defatted soybean meal (SBM) as a substitute for fish meal (FM) in a newly developed soft-dry pellet (SDP) was evaluated by feeding SDP containing 0-50% SBM to both juvenile and adult yellowtail. Palatability or acceptability of the experimental SDP was not influenced by the inclusion of SBM up to 50%. Growth and feed gain ratio were highest in both sizes of fish fed on the control FM diet but decreased corresponding to the elevation of SBM levels. This might be due to the reduced levels of protein and energy in the SBM diets resulting from the difference in protein and lipid contents between FM and SBM, as the diets were not iso-nitrogenous and iso-caloric. This was also supported by the result that the weight gain per digestible energy or protein intake did not differ greatly among the experimental groups. A diet with 25 % SBM and 15% corn gluten meal (CGM) showed better feed performances than the 40% SBM diet, suggesting the availability of CGM as a protein source in combination with SBM. These results together with hemochemical assessments and rheological properties have shown that SBM can be included as a protein source up to 30% in place of FM in SDP for yellowtail without any adverse effects.

Development of a New Type of Dry Pellet for Yellowtail.

This study was conducted to develop a dry type of pellet with a high palatability and acceptabili-ty for yellowtail in order to reduce aquaculture wastes and the occurrence of various fish diseases due to raw fish feeding as well as to improve the quality of the cultured fish. After several feeding trials a completely new type of dry pellet (soft-dry) with a high palatability was succesfully produced by a twin extruder. This pellet contained 8-12% moisture but softer than ordinary hard pellets. Its dietary value was compared by feeding juvenile yellowtail weighing 340g on average with moist pellets prepared by mixing sardine and mash in a ratio of 8:2 or soft-dry for about 4 months in net cages (8 × 8 × 8m). Fish fed the moist pellets grew up to about 980g, while the average body weight of fish fed soft-dry was 1180g, quite higher than those on moist pellets. The average feed gain ratio on dry matter basis during 4 months feeding was 1.50 for soft-dry and 1.79 for the moist pellet, respectively. The survival rate was more than 85% in both the groups. Thus, the newly developed soft-dry pellet has been found to have a nutritional quality superior to the moist pellet.