Effects of salinity and food on growth and survival rate of mangrove snail (\(\textit{Nerita balteata}\) Reeve, 1885) at the spat larvae stage

Mangrove snail (Nerita balteata) belongs to gastropoda species distributed in the coastal intertidal and offshore islands of Quang Ninh province. Although the artificial seeds production of this species have been successful but still having a bottle neck as a low survival rate in the process by veliger larvae are transformed into spat larvae stage. Experiments were conducted to determine effects of salinity and food on growth rate and survival rate of mangrove snail in the stage of spat larvae in Quang Ninh province. The results showed that the optimal salinity for growth and developtment of spat larvae was 25‰ that resulted in a absoluted growth rate of 16.5 ± 2.19 µm/day and survival rate of 26.5 ± 0.57% and significantly higher compared to other treatments. The diet of benthic microalgae (Navicula sp.) combined with formulated feed (AP0 and Frippak) were most suitable for the growth and development of mangrove snail at the spat larvae stage with absoluted growth rate of 25,7 ± 1,28 µm/day; Whereas the survival rate of larvae of 32,3 ± 2,52% was significantly higher than those in the other treatments.

Solid-State Hydrolysis (SSH) Improves the Nutritional Value of Plant Ingredients in the Diet of Mugil cephalus

The possibility of improving the nutritional quality of plant byproducts (brewers’ spent grain and rice bran) through an enzyme treatment was tested in a formulated feed for grey mullet (Mugil cephalus). The enzyme treatment was carried out by Solid-State Hydrolysis (SSH) using a commercial preparation including carbohydrases and phytase. A feed prepared without the treatment and a commercial feed for carp were used as controls. In a preliminary short-term trial carried out at laboratory facilities, fish receiving the enzyme-treated feed showed significant improvement in both FCR and SGR when compared to those obtained with the untreated diet, although both experimental diets presented worse values than those obtained with the commercial feed. Different metabolic indicators including higher values of muscle glycogen and plasmatic triglycerides supported the positive effect of the enzyme treatment on the nutritional condition of the fish over those fed on the diet containing non-treated ingredients. Results of growth and feed efficiency that were obtained in a second long-term trial developed for 148 days under real production conditions evidenced the equivalence among the experimental and commercial diets and confirmed that enzyme pretreatment of plant ingredients by SSH may be a useful procedure to improve the nutritive value of high fiber plant byproducts when included in practical diets for this species and others with similar nutritional features.

Potential of shea fruit-based ingredients for the feed industry

Background The cost involved in feeding poultry is very high especially in most developing countries. To this end, the effectiveness of the fruit pulp of Vitellaria paradoxa (shea), an agro-industrial by-product that is discarded in the processing of the nut for shea butter extraction was investigated on twelve poultry birds assigned to three groups A, B and C (control). Dried samples of the fruit pulp were analysed for their nutrients. Results Proximate analysis of the shea fruit pulp revealed a carbohydrate content of 41.14%, crude fibre 26.62%, crude protein 10.34%, ash 9.23%, crude fat 3.55% and 9.13% for moisture. It also contained essential minerals such as Ca (587 mg /100 g dw), Na (138.30 mg /100 g dw), Mg (1358 mg /100 g dw), K (771.5 mg /100 g dw), Fe (29.88 mg/100 g dw), Zn (40.31 mg/100 g dw) and Cu (8.11 mg/100 g dw). Heavy metals such as Cd, Mn, Pb and Cr were below detectable limits. Measured parameters were live body weights and some selected blood chemistry tests. Broilers in groups A and B fed on shea fruit pulp formulated with maize meal showed a significant growth performance in weight (p < 0.05) as compared to group C fed on maize meal only. Selected blood chemistry tests carried out included Ca, Na, K, Albumin, Triglyceride and Chloride. Statistical analysis showed that formulated feed had a significant effect (p < 0.05) on blood chemistry values of broilers, however, there was an insignificant effect (p > 0.05) in the control group, fed on maize meal only. Conclusion The fruit pulp of Vitellaria paradoxa could be considered a good source of macro and micronutrients and could be used as a supplement in poultry feed.

Effects of feed on fatty acid composition in muscles and gonads of the Chinese mitten crab (Eriocheir sinensis)

In this study, the effects of different feeds on fatty acid composition in the Chinese mitten crab (Eriocheir sinensis) were investigated. The fatty acid composition in the Chinese mitten crab was significantly correlated with the type of feed source provided. Differences between the feed groups pertained mainly five fatty acids: oleic acid, linoleic acid, palmitic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The content of EPA and DHA was higher in the group of frozen trash fish than in the group of formulated feed. On the other hand, the content of oleic acid, linoleic acid and palmitic acid was higher in the formulated feed group than in the frozen trash fish group. There were significant differences in the nutritional value of the Chinese mitten crab reared under different feed sources, i.e. Chinese mitten crabs reared with the frozen trash fish feed were larger than those reared with the formulated feed, especially as regards the ω-3/ω-6 PUFA ratio and essential fatty acid levels.

Efficacy of Formulated Feed Preference and Stocking Density on Growth and Survival of Baby Pila globosa Reared in Laboratory Condition

Quality diet as food for raising freshwater snails under laboratory conditions has a significant effect on their growth and the number of egg clutches laid as well as on the size of the snail. Now a days, some innovative farmers of Bangladesh started snail culture within their fish farms in the view of producing snail to use as feed for their Prawn (Macrobrachiam rosenbergii), indigenous catfish (Clarius batrachus) farms, domestic duck farms and also as a protein supplement for preparing fish feed. From previous study we know that Bulinus nyassanus growth and survive rate was found well on locally formulated fish diet consisting of 30% crude protein with ingredients comprising fish meal, maize bran, rice bran, soya bean, wheat bran, hemicellulose (binder), vitamin premix and mineral premix. But no such research has been done in case of apple snail. The present study was aimed to investigate the feed formulation preferred by Pila globosa species and their effects on survival and growth of these snails in laboratory condition. Three type of formulated feed viz., pellet feed, fish meal and 50% fish meal + 50% crusted khudipana were used for the experiment in high and low stocking density of baby snails. The present findings shown that the diets in order of preference based on their effects on growth and survival of snails were formulated pellet feed, fish meal and 50% fish meal+ 50% crushed khudipana. After rearing of 28 days, highest growth found 0.32g with 86.66% survival with formulated diet in 60nos/L stocking density and 0.35g with 90% survival with formulated diet in 30nos/L stocking density. It`s indicate that the snails reared on formulated pellet feed diets and lower stocking density gave better performance in terms of survival and mean growth rate than those reared on other diets.

PEFORMA PERTUMBUHAN IKAN KAKAP PUTIH (Lates calcarifer) PADA FASE PEMBESARAN YANG DIBERI PAKAN DENGAN PENAMBAHAN LISIN BERBEDA

This study aims to determine the best dose of the amino acid lysine in formulated feed for the growth of white snapper (Lates calcarifer) in the enlargement phase. The research design used three treatments and three replications with a completely randomized design method (CRD), namely control feed formulations with the addition of 0% lysine, P1 formulated feed with the addition of 0.2% lysine, and P2 feed formulations with 0.4% lysine. The test fish used was white snapper with an average weight of 90 grams. Fish reared in fiber tub volume of 2 m3 with the stocking 6 animals/m3. The results showed that feeding P2 formulation had a significant effect on growth in absolute weight, absolute length, daily growth rate, FCR, protein retention but had no significant effect on the survival rate and amino acid lysine retention. P2 feed (formulated feed with 0.4% lysine) can be used to support the growth of white snapper.

Effects of attractants inclusion on the growth and survival of Channa striata

An experiment was conducted to evaluate the efficacy of different natural and artificial attractants in the diet of stripped snakeheads Channa striata. The experiment was conducted into two phases- Nursery and Grow-out. There were four treatments TC (Control), TG (Glycine), TA (Alanine) and TN (Nappi) for each phase with three replicates. In phase-1, the fry/fingerling were fed three times daily for four months; in phase-2, the fish were fed twice daily in the morning and afternoon for six months where the effects of formulated diets were compared with control (TC) which is locally available as commercial feed. In phase-1, significantly (p<0.05) lower FCR (1.58±0.13), higher individual weight gain (91.90 g), higher SGR (2.47±1.79 %/day), higher survival (90%), and higher feeding efficiency (57.60±5.54%) were found in the control (TC) compared to all other treatments. On the other hand, in phase-2, significantly (p<0.05) lower FCR (1.63±0.06), higher individual weight gain (299 g), and higher feeding efficiency (45.96±1.63%) were found in Nappi (TN) supplemented diet whereas significantly (p<0.05) higher survival (93.33%) and higher SGR (0.90±0.17 %/day) were found in Glycine (TG) supplement diet compared to the control (TC). Therefore, domestication and then the addition of natural and artificial attractants in formulated feeds may enhance the efficacy of formulated feeds for better growth and survival of the carnivorous fish like stripped snakeheads especially in grow-out phase. Hence, this finding will help to culture C. striata using protein-rich formulated feed adding attractants rather than depending on any live feed or formulated feed which is not commercially feasible.

Use of Pelleted Diets in Commercially Farmed Decapods during Juvenile Stages: A Review

The increasing market demand for decapods has led to a considerable interest in cultivating decapod species at a larger scale. Following the development of hatchery technologies, most research has focused on the development of formulated feeds for commercially farmed decapods once they enter the juvenile stages. The use of formulated feed for decapods at a commercial scale is still in the early stages. This is probably because of the unique feeding behavior that decapods possess: being robust, slow feeders and bottom dwellers, their feeding preferences change during the transition from pelagic larvae to benthic juveniles as their digestive systems develop and become more complex. The current practice of decapod aquaculture involves the provision of juveniles with food such as natural diet, live feed, and formulated feed. Knowledge of nutrient requirements enables diets to be better formulated. By manipulating the levels of proteins and lipids, a formulated feed can be expected to lead to optimal growth in decapods. At the same time, the pellet’s physical characteristics are important factors to be considered upon formulating commercially farmed decapod feeds, considering the unique feeding behavior of the decapod. However, most published studies on decapod nutrition lack data on the physical characteristics of the feed types. Thus, it is difficult to establish a standard feed formulation that focuses on the physical pellet properties. Moreover, careful consideration must be given to the feeding behavior of species, as decapods are known as bottom feeders and are robust in terms of handling feed. Information on the pellet forms, diet composition, and unique feeding behaviors in commercially farmed decapods is gathered to suggest potential better formulated diets that can optimize growth and reproduction. Thus, the purpose of this review is to summarize the information that has been published to date and to come up with suggestions on ways to improve the feed formulation in decapods that comply with their feeding behavior and nutrient requirements. Further research is needed to explore the potential of the pelleted feed at the adult stage so the decapod can take full advantage of the nutrients present in the pellets.

A Preliminary Study on Effects of Fermented Feed Supplementation on Growth Performance, Carcass Characteristics and Meat Quality of Hanwoo Steers during the Early and Late Fattening Period

The present study was conducted to determine the effects of formulated feed (IRG: Italian ryegrass, WCC: whole crop corn, and fermented feed) on growth performance, carcass characteristics, and meat quality of Hanwoo steers during early and late fattening periods. Twelve Hanwoo steers were randomly assigned into two groups: control and treatment (n = 6/group). The control group received rice straw with concentrate; the Treatment group received formulated feed for 13 months. Results revealed that formulated feed supplementation significantly (p < 0.05) increased effects on dry matter (DM) intake, body weight, average daily gain, and carcass yield than control feed. Hanwoo steers fed formulated feed showed higher meat quality, carcass yield, and ribeye area than steers fed control feed. However, meat quality characteristics (such as cooking loss, fat thickness, marbling score, meat color, and crude fat), sensory characteristics, and pH values were similar between the two groups (all p > 0.05). There was no significant difference in FA compositions of steers between the two groups (p > 0.05). Overall, these results indicate that feeding Hanwoo steers with formulated feed can improve their growth efficacy, carcass yield, and meat quality characteristics during early and late fattening periods. Regarding an economic strategy, our research findings suggest that formulated feed is effective and profitable for feeding Hanwoo steers during early and late fattening periods without causing adverse effects.