Feed Efficiency Ratio Research Articles

The Effect of Feeding Maggot Fluor (Hermetia illucens) on Fish Feed for Growth of Sangkuriang Catfish (Clarias sp)

One of the problems among breeders is the high need for food. An effort to reduce the cost of catfish feed is to provide maggot flour (Hermetia illucens L.) as a basic material for making food. Our study attempted to measure the effect of maggot flour (Hermetia illucens L.) on the growth of 2 month old Sangkuriang catfish (Clarias sp.). The data were compiled using a completely randomized design technique (CRD) with 4 replications and 6 treatments for catfish, namely the provision of maggot concentrations of 10% (P1), 20% (P2), 30% (P3), 40% (P4), 50% (P5 ), control treatment (without maggot) and calculated using ANOVA. The 50% and 40% maggot percentages provided an increase in all growth parameters. The statistical test at a significant level of 1% showed that feeding maggot flour had a significant effect (P > 0.05) on absolute length and relative length, but had no significant effect on absolute weight, relative weight and feed efficiency ratio. Provision of maggot flour could increase the growth of 2 month old Sangkuriang catfish (Clarias sp.) on growth parameters and provide solutions in reducing feed costs.

UJI EFEKTIVITAS PEMBERIAN MINYAK KEMIRI (Aleurites moluccanus) PADA PAKAN KOMERSIAL TERHADAP TINGKAT KONVERSI PAKAN DAN EFISIENSI PAKAN IKAN BILEH (Rasbora sp.)

The objective of the present study was to evaluate the giving candlenut oil (aleurites moluccanus) in commercial feed on feed conversion ratio and feed efficiency of bileh fish (Rasbora sp.). Thecompletely randomized design method was used in this study with four treatments and three replications. The treatments studied were pellet without the giving candlenut oil (P0), pellet with the giving candlenut oil 5%/kg of feed (P1), pellet with the giving candlenut oil 10%/kg of feed (P2) and pellet with the giving candlenut oil 15%/kg of feed (P3). Bileh fish seed stocking density was 1 individu/l with the length of 3,5-4 cm and weight of 0,61-0,86 g. The culture period of fish farming was 40 days. The ANOVA test showed that the commercial feed with the giving candlenut oil gave significant effect on feed conversion ratio, feed efficiency, specific growth rate of bileh fish (Rasbora sp.), but did not give significant effect on survival rate of bileh fish seed. The best dose to increase feed efficiency and low feed conversion ratio of bileh fish seed is pellet with the giving candlenut oil 15%/kg of feed (P3).

Assessment of isoleucine requirement of fast-growing Nile tilapia fingerlings based on growth performance, amino acid retention, and expression of muscle growth-related and mTOR genes

Recent studies provide new mechanistic insights that isoleucine (ILE) regulates protein synthesis through genomic approaches. An 8-week feeding trial was performed to determine dietary ILE requirement based on growth performance, body composition, amino acid (AA) retention, and mRNA levels of myogenic regulatory factors (MRFs), including myogenic differentiation (MyoD), myogenin (MyoG), and myostatin (Mst) as negative regulatory of myogenesis, and mammalian target of rapamycin (mTOR) genes in fingerling Nile tilapia, Oreochromis niloticus. Fish (n = 288; 2.46 ± 0.10 g; mean ± SD) were randomly distributed into six treatments with four replicate groups of 12 fish. Fish were fed diets with graded levels of analyzed ILE at 9.08 (ILE1), 12.13 (ILE2), 15.11 (ILE3), 18.02 (ILE4), 21.15(ILE5), and 24.06 g kg−1 diet (ILE6). Fish were hand-fed, six times a day, until apparent satiety. At the end of the feeding trial, incremental levels of dietary ILE significantly affected body weight gain (BWG), feed efficiency ratio (FER), protein retention efficiency (PRE), and essential and non-essential AA retention. Also, the relative expression of MyoD and MyoG genes in the white skeletal muscle and mTOR gene in the liver was up-regulated in fish fed diet ILE3 (P > 0.05). Optimal branched-chain amino acid (BCAA) ratio (Ile:Leu:Val) was found at 1:1.3:0.9. Based on one-slope broken line model of BWG, the optimal dietary ILE requirement for fingerling Nile tilapia was estimated at 13.67 g kg−1. The results indicate that appropriate dietary ILE level at 5.0% dietary protein could improve protein synthesis and positively regulates muscle growth-related and mTOR genes in fast-growing Nile tilapia.

THE USE OF ACTIVATED SEWAGE SLUDGE IN BROILER DIETS

The effect of dried activated sewage sludge on the growth and protein utilization of broiler was studied. The eight weeks feeding trial involving one hundred and eighty day-old broiler chicks, weighting 57.80 – 58.00g in a completely randomized design were fed three diets containing 0% (control), 10% and 15% dried activated sewage sludge. The dried activated sewage sludge was found to be high in protein and ash (24.24% and 41.80%) but low in either extract and fibre (3.0% and 3.50%) respectively. At the 10% level of inclusion in the diet, the activiated sewage sludge gave significantly (P < 0.05) better weight gains than the control and 15% levels of inclusion. The feed efficiency and protein efficiency ratios were also significantly (P < 0.05) better at 10% inclusion when compared with the control and 15% levels of inclusion. There was no incidence of enteritis and percentage mortality was statistically insignificant at 5% level.

The Effect of Difference Culture Media Maggot Black Soldier Fly Hermetia illucens (Linnaeus, 1758) (Diptera: Stratiomyidae) on the Growth of Striped Catfish Seeds Pangasianodon hypophthalmus (Sauvage, 1878) (Pangasiidae)

The purpose of this study was to determine the type of maggot media that can produce the highest survival, growth, feed efficiency and lowest feed conversion ratio (FCR) to Striped catfish fingerling. This research was conducted during July 2020 – January 2021 at the Laboratory of Building 4, Faculty of Fisheries and Marine Sciences, Universitas Padjadjaran. The research method was carried out experimentally using the Completely Randomized Design (CRD) method and four treatments. The treatment given is a combination of commercial feed and maggot with different media consisting of A (50% commercial feed + maggot with 50% mixed media), B (50% commercial feed + maggot with 50% fruit media), C (50% commercial feed + maggot with 50% layer media) and D (50% commercial feed + maggot with 50% bran media). The parameters observed were survival, daily weight growth rate, length, feed efficiency, food conversion ratio and water quality. . Giving a combination of 50% commercial feed and cultured maggot with mixed media of 50% gave the best daily growth rate, length growth and feed efficiency results, namely 1.23%, 0.99% and 62.79% and the lowest feed conversion ratio value. that is 1.67.

Utilization of Fermented Salted Marine Trashfish Meal for Replacing Fishmeal in Nemurus Catfish (Hemibagrus nemurus) Diets

This research was carried out to determine the substitution values of fermented salted marine trash fish (FSMTF) for dietary conventional fishmeal (CFM) on growth of nemurus catfish. Four isoproteic (34% crude protein) and isocaloric (3.15 kcal DE g−1) diets were formulated. One diet was a control diet (C) in which 44% CFM was included and no FSMTF. Other three diets were test diets in which CFM was substituted with FSMTF, 50% (FSMTF-50), 75% (FSMTF-75) and 100% (FSMTF-100). A commercial diet (COM) which composed of 31 % crude protein and 2.90 kcal DE g−1 was also tested as a comparison. Nemurus catfish, 47±3.94 g in weight were distributed into triplicate net cages (2x2x1.5 m), 40 fishes per m3 water, and fed experimental diets two times daily for two months. Total substitution of fishmeal with FSMTF (FSMTF-100) in the fish diet did not affect fish growth (weight gain, specific growth rate, survival rate), feed efficiency ratio, protein efficiency ratio and protein utilization as compared to control diet. Total substitution of CFM with FSMTF gave better feed efficiency ratio, protein efficiency ratio and protein utilization than commercial diet. FSMTF therefore can completely replace CFM in the diet of nemurus catfish.

Nutritional and Biological evaluation of using Spirulina algae as anew source of protein

Spirulina platensis (SP) alga has been a common dietary substance around the world from ancient times. This study was aimed to using Spirulina as a novel protein source, especially in growth phase. Thirty six male albino rats aged six weeks were divided into six groups according to the protein source as following: The casein groups (C1, C2, and C3) contain (100, 200, and 300 g casein /kg diet) as (10%, 20% &30% casein), respectively. On the corresponding side, the spirulina clusters (SP1, SP2, and SP3) contained (157, 315 and 472 gm algal protein/kg food) respectively. It lasted 28 days. SP has high total antioxidant activity (39.2 %). SP groups recorded significant increases in feed intake, body weight gain, feed efficiency ratio and protein efficiency ratio compared with casein groups. While casein recorded significant increases in apparent digestibility, Co-efficient compared to groups of SP algae. Eating Spirulina has significantly preserved liver and kidney function. As for complete blood picture, the groups of SP3 recorded highest percentage in Hb and RBCs compared with C3 group, other than WBCs, which was lower in SP3. Significant increase in the antioxidant enzymes in liver tissues were observed in SP groups, while Malondialdehyde recorded a significant reduction in the same groups. SP treatment increased GH levels in all groups. On the other side, the results of alpha tumor necrosis factors recorded a significant decrease in groups of SP compared with the groups of casein. In conclusion, Spirulina can be used as a new protein replacement

Utilization of Corchorus olitorius leaf as binder in the diet of Oreochromis niloticus fingerlings

Abstract. This study was carried out to evaluate the physical properties and dietary value of feeds made using Corchorus olitorius as binders in fish feeds. Six isonitrogenous diets were prepared using maize wheat or maize and wheat as energy source. The diets were designated as MAI, WHC, MAW, MAC, WHC and MWC. With the first three being bounded with corn starch and the last three being bounded with C. olitorius leaves soaked for 24 hours and pelleted. Physical properties evaluated are sinking rate, water absorption index, water stability, bulk density, thickness strength, friability and hardness. There was significant differences (p<0.05) in the water stability, water absorption index and thickness swelling of the diet. The highest water stability value was recorded in diet MAW. For growth parameters and nutrient utilization by fish fed experimental diets, diet MWC had a significantly higher mean final weight (9.42±0.41g), mean weight gain (5.43±0.41g), feed efficiency ratio (0.93±0.13) and specific growth rate (1.22±0.06%d-1). There was no significant difference in the feed conversion ratio, mean feed intake, and survival rate. The result shows that diet bounded with C. olitorius leaf had better utilization compared to corn starch bounded feed.

Optimization of stocking density and feeding ration for rearing of stunted Labeo rohita fingerlings in cages

Aim: To rear stunted Labeo rohita fingerlings in cages and determine the optimum stocking density and feeding ration for better growth performance of fishes. Methodology: Eight-month-old stunted fingerlings of Labeo rohita (14.65cm/38.23g) were stocked in floating net square cages at different stocking densities (10, 15, 20 and 25 fishm-2) and fed with different feeding ration (3%, 4%, 5% and 6% of body weight), further reared for 330 days and fed twice a day with commercial floating pellets with 25% crude protein. The study followed 4*4 factorial design and were triplicated for each treatment and level. Results: The study found a decrease in the final body weight, average body weight gain, and specific growth rate with increasing stocking density. The highest final body weight (732.64 g), body weight gain (694.30 g) and specific growth rate (0.89 % day-1) were recorded in 10/m2 stocking density with feed ration of 6% body weight. In contrast to this, fish reared in higher stocking density (25/m2) exhibited poor feed conversion ratio. Fish reared in lower stocking density (10/m2) and fed with 6% feeding ration displayed an enhanced feed conversion ratio, feed efficiency ratio and protein efficiency ratio which indicated that rearing of stunted rohu in intensive cage culture at lower stocking density (10/m2) with higher feeding ration (6%) increase their feed utilization capacity. Interpretation: Rearing of stunted rohu in intensive cage culture is possible, however, the stocking density and feeding ration should be 10/m2 and 6%, respectively, compared to traditional cage practices, in order to reduce stress and to get optimum production. Key words: Cage culture, Feeding ration, Fingerling, Labeo rohita, Stocking density

Black Soldier Fly Full-Fat Larvae Meal is More Profitable than Fish Meal and Fish Oil in Siberian Sturgeon Farming: The Effects on Aquaculture Sustainability, Economy and Fish GIT Development.

Simple SummaryThe practical use of alternative feed materials must be both sustainable and profitable. Therefore, the aim of this study was to assess the impact of black soldier fly full-fat larvae meal (BSFL) on environmental and economic aspects as well as gastrointestinal tract (GIT) development in Siberian sturgeon nutrition. The experimentally obtained data were used for calculations of fish meal (FM) and fish oil (FO) relative usage per kg of fish gain. The economic conversion ratio and profitability per unit of fish gain were assessed also. The samples of intestinal and liver tissues were analysed in terms of villi height, width, and surface, and liver health. The study showed a high potential of BSFL usage up to its highest used incorporation that was 30% of the diet. The environmental sustainability of the diets was increased not only by the reduction in FM and FO use but also by the increase in feed conversion efficiency. Thus, even though the price of BSFL was higher than FM and FO, the profitability of fish production was improved, finding its optimum at the levels of 10% and 15% BSFL incorporation. Moreover, health beneficial effects of BSFL were observed in alterations of GIT development.This study provides data on the environmental sustainability, economic profitability, and gastrointestinal tract development of Siberian sturgeon diets containing black soldier fly full-fat larvae meal (BSFL) for a fish meal (FM) and fish oil (FO) replacement. BSFL was used at 5%, 10%, 15%, 20%, 25%, and 30% of the diet, replacing by up to 61.3% of FM and 95.4% of FO. BSFL positively affected the feed efficiency ratio, and lowered FM and FO usage per kg of fish gain. All the BSFL diets showed a sustainable fish-in fish-out (FIFO) ratio, which was lowered by up to 75% in comparison to the control. Economic assessment per kg of fish gain showed that the most lucrative variants were variants with 10% and 15% BSFL, it finds a mode of action in improvements of the gastrointestinal tract development, including increased pyloric caeca and proximal intestine shares and enhanced villus height and area. Thus, in Siberian sturgeon, BSFL may be used not only as an FM and FO replacer but also as a functional material due to its feed utilization and beneficial health effects, which are reflected in its high sustainability and favourable economics.

Improvement in the growth status and carbohydrate utilization of Labeo rohita (Hamilton, 1822) fingerlings with dietary supplementation of chromium picolinate.

A 60-day feeding experiment was conducted to evaluate the effects of dietary chromium (Cr) on carbohydrate utilization and growth performance of Labeo rohita fingerlings. Fishes were fed with four high carbohydrate (53%), isonitrogenous (crude protein 35%), and isocaloric (415 Kcal, 100 gm-1) experimental diets containing different levels of dietary chromium picolinate (Cr-Pic) viz.0, 400, 800, and 1200 μg kg-1 diet. Weight gain (WG%), specific growth rate (SGR), feed efficiency ratio (FER), and protein efficiency ratio (PER) were significantly increased at 800 μg kg-1 diet chromium supplementation (P < 0.05). Cr-Pic supplementation (800 μg kg-1) also significantly (P < 0.05) enhanced the protein: DNA ratio in muscle, while DNA: RNA and DNA: tissue ratios were significantly (P < 0.05) decreased indicating higher growth. Significantly higher amylase, protease, and lipase activities were recorded in 800 μg Cr-Pic kg-1 diet fed fishes (P < 0.05), while any of the experimental groups showing no significant (P > 0.05) change in hexokinase activity, indicating normal glycolysis in all. Furthermore, significant (P < 0.05) decrease of glucose-6-phospatase activity in 800 μg Cr-Pic kg-1 diet fed group, showcasing an evidence for protein-sparing action with Cr-Pic supplementation. Significantly (P < 0.05) higher serum insulin and liver glycogen in 800 μg Cr-Pic kg-1 diet fed fishes denote an improvement in carbohydrate metabolism. However, significantly (P < 0.05) higher ATPase and SOD activities were also observed when chromium supplementation was more than 800 μg kg-1 diet, indicating stress at higher level. The present study indicates that growth and carbohydrate utilization can significantly (P < 0.05) be improved by feeding the L. rohita fingerlings with Cr-Pic (800 μg kg-1 diet) supplemented diet in laboratory condition.

Effects of dietary lipid level on growth performance, feed utilization, fatty composition and antioxidant parameters of juvenile walleye pollock, Gadus chalcogrammus

We evaluated effects of dietary lipid level on growth performance, feed utilization, fatty acid composition, plasma chemistry, and antioxidant responses in juvenile walleye pollock (Gadus chalcogrammus). Two-hundred forty juvenile pollock averaging 4.4 g in weight were randomly distributed between 12 400-L flow-through circular tanks (20 fish per tank). Fish were fed four isonitrogenous experimental diets with crude lipid levels of 8.1%, 12.6%, 16.7%, or 20.8% for 8 weeks. Each diet was assigned to three tanks, and the fish were hand-fed to satiation twice daily. At the end of the trial, weight gain, specific growth rate, feed efficiency, and protein efficiency ratio were increased with increasing dietary lipid up to 16.7%, and then decreased with a further increase in dietary lipid. The hepatosomatic index showed an increasing trend with increasing dietary lipid. The crude lipid content in liver increased with increasing dietary lipid. Saturated fatty acid levels in the muscle and liver decreased, whereas essential fatty acids and polyunsaturated fatty acids in the muscle and monounsaturated fatty acids in the liver increased with increasing dietary lipid. The hematological and antioxidant parameters were not affected by the dietary lipid content. In conclusion, on the basis of a second-order polynomial regression analysis of weight gain, the optimum dietary lipid level for juvenile walleye pollock was estimated to be 15.8%.

Dietary hydroxyl methionine selenium supplementation enhances growth performance, antioxidant ability and nitrite tolerance of Litopenaeus vannamei

An 8-week feeding trial and then 12 h nitrite stress was conducted to estimate the effects of dietary hydroxyl methionine selenium (HMSe) on growth performances, antioxidant response and nitrite resistance of Litopenaeus vannamei (initial weight 0.90 ± 0.05 g). The diet was supplemented with 0, 0.15, 0.30, 0.60 and 0.90 mg Se/kg as HMSe to formulate six diets, labeled as HMSe0, HMSe15, HMSe30, HMSe60 and HMSe90, respectively. The results showed that significantly higher finial body weight and weight gain were observed in HMSe30 group than those in HMSe0 and HMSe90 groups (P < 0.05). Feed efficiency and protein efficiency ratio of HMSe30 were significantly higher than those of HMSe90 (P < 0.05). The selenium contents in whole body and muscle were both significantly increased with the dietary HMSe levels increasing (P < 0.05). The hepatopancreas MDA levels of groups supplemented HMSe were significantly lower than that of HMSe0 (P < 0.05). And they decreased firstly and then increased with HMSe supplementation levels increasing, the lowest concentration was observed in HMSe15 group. The antioxidant enzymes of GSH-Px, SOD, CAT and GST activities in hepatopancreas were firstly increased and then decreased with the increase of dietary HMSe levels. GSH-Px, SOD and CAT genes expression in hepatopancreas were significantly up-regulated in HMSe15, HMSe15 and HMSe60 groups. After nitrite stress, there were higher mortality and hepatopancreas MDA concentration and lower hepatopancreas GST, CAT and SOD activities in HMSe0 group. While, these negative effects could be relieved with HMSe supplementation. In conclusion, HMSe could improve the growth performance, antioxidant capacity and nitrite tolerance of L. vannamei. The optimal supplementation for L. vannamei is 0.431 to 0.454 mg Se/kg as HMSe based on weight gain and hepatopancreas GSH-Px activities using the second-order polynomial regression analysis.

Chitosan and chitooligosaccharides attenuate soyabean meal-induced intestinal inflammation of turbot (Scophthalmus maximus): possible involvement of NF-кB, activator protein-1 and mitogen-activated protein kinases pathways

An 8-week feeding experiment was conducted to investigate and confront the putative functions of chitosan (CTS) and chitooligosaccharide (COS) in the growth and homoeostasis of distal intestine in juvenile turbots fed diets containing soyabean meal (SBM). Three isolipidic and isonitrogenous diets were formulated by supplemented basal diet (based on a 400 g/kg SBM) with 7·5 g/kg CTS or with 2·0 g/kg COS. Our results indicated that both CTS and COS supplementation could significantly improve (i) the growth performance and feed efficiency ratio; (ii) antioxidant activity driven by metabolic enzymes (i.e. catalase, glutathione reductase, glutathione peroxidase and superoxide dismutase); (iii) glutathione levels; (iv) acid phosphatase and lysozyme activity and (v) IgM content. As a result, these two particular prebiotics were able to significantly attenuate the histological alterations due to local inflammation as well as to decrease the transcriptional levels of proinflammatory cytokines (i.e. IL-1β, IL-8 and TNF-α) and major pathway effectors (i.e. activator protein-1 (AP-1), NF-кB, p38 mitogen-activated protein kinase, c-Jun N-terminal kinase and extracellular regulated kinase). High-throughput sequencing data indicated that dietary CTS and COS could significantly decrease the diversity of intestinal bacteria but elevate the relative abundances of Bacillus, Lactobacillus and Pseudomonas genera. Altogether, these findings suggest that CTS and COS can improve growth of turbot, enhance intestinal immune and anti-oxidant systems and promote the balance of intestinal microbiota. The protective effects, elicited by these two prebiotics, against SBM-induced inflammation could be attributed to their roles in alleviating the overexpression of inflammatory cytokines by possibly down-regulating NF-кB, AP-1 and/or mitogen-activated protein kinases pathways.

Comparative Study Between Virgin Coconut Oil and Omeprazole Drug on Ulcerative Colitis in Experimental Rats

This study aims to identify the curative effect of virgin coconut oil on ulcerative colitis(UC),the present study was carried (24) adult albino male rats Sprague –Dawley strain weighting 180 ±10g were classified into four groups,(6 rats each) the first group rats were fed on basal diet only control negative(-ve) group and three rat groups were injured of ulcerative colitisby intra colonic administration of acetic acid 4% given rectally by single dose ( 1 ml/ rat ) and reclassified into control positive (+ve) group (fed on basal diet only), group treated with (20 mg/kg b.w) of omeprazole drug and group treated with (2 ml per/ rat) daily of virgin coconut oil . The results revealed that, the control (+ve) group showed a significant decrease in final weight(FW) ,weight gain(WG) feed efficiency ratio (FER), organs weight of heart, kidney, and liver , catalase (CAT), superoxide dismutase (SOD), glutathione reduced (GSH), Glutathione reductase (GSR),Glutathione peroxidase (GPx(, glutathione-S-transferees (GST) and significant increase in malondialdehyde (MDA) , hydrogen peroxide (H2O2), C-reactive protein (CRP), interleukin-6 (IL-K) and prostaglandin (PG2) compared with control (- ve) group. The virgin coconut oil group showed a significant increase in (FW),(WG),(FI),(FER),organ stomach,(CAT),(SOD),(GSH),(GSR (GPx), (GST) but significant decrease in (MDA),(H2O2),(CRP),(ILK), (PG2) compared with control (+ve) group . the study clearly showed that consumption virgin coconut oil has a role in treating rats with acetic acid-induced ulcerative colitis. It can be recommended that virgin coconut oil should be consumed daily to reduce the incidence of ulcerative colitis.

The effect of garlic (Allium sativum) and turmeric (Curcuma longa) extract addition in commercial feed on feeding rate, feed efficiency and feed conversion ratio of gouramy fish (Osphronemus gouramy)

Gouramy is known to it’s low appetite and slow growth. Attractants are ingredients that are mixed in small amounts of feed to increase feed intake, growth, and fish consumption of feed. Garlic contains at least 33 sulfur components that give a distinctive odor and various medicinal effects. Turmeric contains essential oils composed of monoterpenes and is an effective odor stimulating precursor compound used as an attractant. This study aims to determine the effect of giving turmeric and garlic extracts at different doses on feed consumption, feed efficiency and feed conversion ratio in gouramy. This study used an experimental method with 5 treatments; P0= control, P1=1% garlic extract addition, P2= 1.5% garlic extract addition, P3= 1% turmeric extract addition and P4= 1.5% turmeric extract additions with 4 replications using 10 fish in each.. The results showed that the highest feed consumption value was in the treatment of P1and P2, the lowest conversion ratio and the highest value of feed efficiency was found in the treatment of P2 and P3. So it can be concluded that the addition of 1.5% garlic extract or 1% turmeric extract is effective as an attractant and effective for increasing the growth of gouramy.

Substitution effect of fish meal with various sources of animal by‐product meals in feed on growth, feed utilization, body composition, haematology and non‐specific immune response of olive flounder ( Paralichthys olivaceus , Temminck &amp; Schlegel, 1846)

Suitability of various animal by-product meals was evaluated as an alternative source for fish meal (FM) in olive flounder feed when 30% FM was substituted. Juvenile fish (n = 480) was distributed into 24 flow-through tanks. Seven experimental diets were prepared. 65% FM and 12% soybean meal were included as the protein source in the control (Con) diet. Thirty per cent of FM was substituted with tuna by-product, chicken by-product, hydrolysed chicken offal, meat, meat and bone, and blood meals, referred to as the TBM, CBM, HCOM, MM, MBM and BM diets respectively. Each diet was hand-fed to satiation for 8 weeks. Weight gain, specific growth rate (SGR) and feed efficiency ratio (FER) of fish fed the TBM diet were greater than those of fish fed all other diets. Weight gain, SGR and FER of fish fed the Con diet was also greater than those of fish fed the MM and BM diets. The proximate composition of the whole body fish was unaffected by the experimental diets. Lysozyme activity of fish fed the Con, TBM and CBM diets was higher than that of fish fed the MM and BM diets. Amino acid profiles of fish were not affected by the experimental diets except for tryptophan. All fatty acid profiles of fish except for eicosadienoic acid were affected by the experimental diets. In conclusion, tuna by-product and chicken by-product meals are the good substitutes for FM in olive flounder feed when 30% of FM at 65% in diet was replaced with animal by-product meals.

Potential utilization of kombucha as a feed supplement in diets on growth performance and feed efficiency of catfish (Clarias sp.)

Kombucha is a tea beverage obtained from the fermentation of sugared tea by a symbiotic culture of bacteria and yeast. Kombucha is known to have many beneficial effects in health due to its chemical content and a high source of acetic acid and lactic acid bacteria and yeast. This study aimed to investigate the effect of kombucha supplementation in feed on growth performance and feed efficiency of catfish (Clarias sp.). Four hundred fish were distributed randomly into five feeding treatment groups includes a basal diet (control) and kombucha supplementation in the fish diet at 4 mL, 6 mL, 8 mL, and 10 mL/kg of feed. The feed was administered for 30 days. Results showed that the administration of kombucha in feed significantly improved the growth performance of catfish (P<0.05). Fish fed with kombucha supplementation at 8 mL produced the highest weight gain, absolute growth rate, and specific growth rate. Feed conversion ratio and feed efficiency ratio were significantly enhanced in the administration of 8 mL kombucha in a fish diet compared to the control diet. This study indicated that administration of kombucha in fish diet had a potential for enhancing the growth performance and feed efficiency of catfish (Clarias sp.)

Effect of dietary methionine on growth performance, lipid metabolism and antioxidant capacity of large yellow croaker (Larimichthys crocea) fed with high lipid diets

A 10-week feeding trial was conducted to evaluate the effect of dietary methionine (MET) on the growth performance, lipid metabolism and liver antioxidant function in juvenile large yellow croaker (Larimichthys crocea) fed with high lipid diets (HLDs). Large yellow croaker with an initial average weight of 8.59 g, were fed with basic HLD (lipid level at 18%, HL), basic HLD supplemented with 0.6% MET (HL/L-MET) and basic HLD supplemented with 1.2% MET (HL/H-MET). Results indicated that dietary MET did not affect weight gain, specific growth rate and feed efficiency ratio (P > 0.05). The MET supplementation in large yellow croaker also did not affect the content of total lipid in whole body (HL = 9.57, HL/L-MET = 8.92 and HL/H-MET = 8.71%), liver (7.34, 16.68 and 14.37%) and muscle (10.87, 12.11 and 9.94%) (P > 0.05). However, MET supplementation reduced the size and number of liver lipid droplets as dietary MET increased. Meanwhile, supplementation of MET in HLDs reduced serum total cholesterol (2.65, 2.14 and 1.91 mmol/L), low-density lipoprotein-cholesterol (0.27, 0.21 and 0.16 mmol/L) and triglyceride (4.80, 2.43 and 1.96 mmol/L) (P < 0.05), but increased serum high-density lipoprotein-cholesterol (0.68, 0.77 and 0.83 mmol/L) (P < 0.05). Dietary MET upregulated significantly the mRNA expression of genes related to mitochondrial fatty acid β-oxidation (PPARα and CPT1) and ER stress (GRP78, ATF6α and CHOP) (P < 0.05). Furthermore, feeding fish with MET diets reduced serum alanine transaminase and aspartate transaminase activities, serum and liver malondialdehyde content, and liver 8-hydroxydeoxyguanosine level. Interestingly, feeding fish with MET diets increased liver total antioxidant capacity activity (P < 0.05). In conclusion, dietary MET improved lipid metabolism and increased antioxidant capacity in the liver, but did not affect growth performance in juvenile large yellow croaker fed with HLDs.

Performance and nutrient utilization of rabbits fed diets based on crop residues fermented with Rhizopus oligosporus

This study was conducted to evaluate the performance and nutrient utilization of rabbits fed diets containing corn cob and cowpea husk incubated with Rhizopus oligosporus. A total of twenty four rabbits were assigned to four groups, each divided into three groups of two rabbits per replicate. Four experimental diets containing fermented and unfermented crop residues were formulated. The fermented crop residues were incubated with Rhizopus oligosporus and were allowed to ferment for 48hours. The proximate composition as well as the fibre fractions of the fermented and unfermented crop residues was determined. The experiment was arranged in a 2x2 factorial design and was analysed using analysis of variance. The result indicated that average growth rate of rabbits fed fermented cowpea husk were higher numerically than those fed the other diets. The average weekly feed intake was significantly (p&lt;0.05) affected by the weight gain. Feed efficiency and protein efficiency ratios were not significantly (p&gt;0.05) affected by fibre sources while fermentation did not impose any significant impact on these parameters. Rhizopus fermentation improved the performance and utilization of crude fibre, phosphorus, ADF and NDF by rabbits fed corn cob and cowpea husk. It was concluded that corn cob and cowpea husk possessed the potential as fibre sources in rabbit ration.