Effect of dietary supplementation of brewers y

Aquacult Int (2011) 19:489–496 DOI 10.1007/s10499-010-9364-1 Effect of dietary supplementation of brewers yeast and nucleotide singularly on growth, survival and vibriosis resistance on juveniles of the gastropod spotted babylon (Babylonia areolata) Nilnaj Chaitanawisuti • Chatchaleeya Choeychom Somkiat Piyatiratitivorakul • Received: 16 November 2009 / Accepted: August 2010 / Published online: 18 August 2010 Ó Springer Science+Business Media B.V 2010 Abstract This study was undertaken to evaluate the use of brewers yeast and nucleotides as a growth promoter and to provide vibriosis resistance for the juveniles of gastropod spotted babylon (Babylonia areolata) Juvenile spotted babylon (0.3 g initial weight) were randomly distributed at a density of 50 snails in 45-L aquaria and fed a basic diet (40% crude protein) containing two incremental levels of and 2% brewers yeast and nucleotides singularly for months After the feeding trial, snails from each treatment were challenged by pathogenic bacteria Vibrio alginolyticus given by intramuscular injection and kept under observation for days to record clinical signs and daily mortality rates Results indicated that the snails fed with diets supplemented with brewers yeast or nucleotides exhibited significantly greater growth than those fed the basic diet (P \ 0.05) and significantly better food conversion ratios compared to snails fed the basic diet (P \ 0.05) These results indicated that dietary supplementation of brewers yeast or nucleotides, at least at the tested dosages, enhanced spotted babylon growth Supplementing the diet with 1% brewers yeast promises to provide appropriate resistance to V alginolyticus Keywords Babylonia areolata Á Brewers yeast Á Nucleotides Á Growth performance Á Disease resistance Introduction Spotted babylon Babylonia areolata are popular marine gastropods cultured in Thailand and a potentially important aquaculture species because of their rapid growth, efficient N Chaitanawisuti (&) Aquatic Resources Research Institute, Chulalongkorn University, Phya Thai Road, Bangkok 10330, Thailand e-mail: nilnajc1@hotmail.com C Choeychom Á S Piyatiratitivorakul Department of Marine Science, Faculty of Science, Chulalongkorn University, Phya Thai Road, Bangkok 10330, Thailand 123 490 Aquacult Int (2011) 19:489–496 food conversion and high market value Large-scale rearing of B areolata in Thailand is technically feasible using flow-through systems in concrete/canvas ponds Disadvantages of these systems that must be solved during growth of the spotted babylon were as follows: these systems generally require large quantities of water; production systems must be located near the sea; the stock is vulnerable to external water supply and quality problems; and their growth rate was significantly influenced by water flow (Chaitanawisuti et al 2002) Trash fish is used as food at all commercial farms producing spotted babylon in Thailand The main problems of this food source are its shortage and discontinuous supply and the freshness and variable nutritional values of trash fish This situation has led to research on the development of cost-effective artificial feeds for farmed spotted babylon (Chaitanawisuti and Kritsanapuntu 1999; Chaitanawisuti et al 2005) Proper nutrition has long been recognized as a critical factor in promoting normal growth and sustaining the health of mollusks Prepared diets not only provide the essential nutrients that are required for normal physiological functioning but also may serve as the medium by which fish receive other components that may affect their health Although the concept of functional feeds is novel to the aquaculture industry, it represents an emerging new paradigm to develop diets that extend beyond satisfying basic nutritional requirements of the cultured organisms Prebiotics are defined as ‘‘a nondigestible food ingredient which beneficially affects the host by selectively stimulating growth of and/or activating the metabolism of one or a limited number of health-promoting bacteria in the intestinal tract, thus improving the host’s intestinal balance’’ (Li and Gatlin (2004) Moreover, single-cell proteins (SCP) including microalgae, bacteria and yeast are frequently used as food additives for fish because they contain nutrients, proteins, vitamins, pigments nucleotides, b-glucans Among SCP, some yeast such as Candida sp and Saccharomyces cerevisiae are used as probiotics (Scholz et al 1999; Li and Gatlin 2003) Brewers yeast (Saccharomyces cerevisiae) contains various immunostimulating compounds such as b-glucans, nucleic acids and chitin as well as mannan oligosaccharides, and it has been observed to be capable of enhancing immune responses as well as growth of various fish and shellfish species (Li and Gatlin 2004) In brewers yeast, nucleic acid nitrogen is present mostly in the form of RNA and represents about 20–25% of the nitrogen (Oliva-Teles and Goncalves 2001; LaraFlores et al 2003; Li and Gatlin 2003; Li et al 2005) Dietary nucleotides have been shown to have several benefits including rapid intestinal repair, improved mucosal gut flora and mucosal surfaces and elongation of the intestinal tract in aquatic animals (Li and Gatlin 2006; Li et al 2007) Nucleotides also have been shown to enhance the immune system and disease resistance of various animals (Murthy et al 2009) However, the potential benefit of the dietary supplementation has not been evaluated for the Babylonia areolata Therefore, this study was conducted to determine the effects of brewers yeast and nucleotide supplementation on growth, survival and vibriosis resistance of juvenile spotted babylon (B areolata) Materials and methods Experimental diets Four experimental diets were prepared by adding different supplements to the basic diet The basic diet consisted of a partially autolyzed brewers yeast produced by Thai Beverage Public Company Limited, Bangkok, Thailand, and the commercial nucleotide product 123 Aquacult Int (2011) 19:489–496 491 [(NuProÒ), Alltech Biotechnology Corporation Company, Bangkok, Thailand] NuProÒ is a functional protein from yeast and contains highly concentrated levels of essential and functional nutrients, which are important in the diets of young animals It is rich in nucleotides, inositol, and amino acids and peptides Two incremental levels (1 and 2% of brewers yeast or NuProÒ) were added to the basic diet, and fishmeal, tuna oil and cellulose were adjusted to provide isonitrogenous (40% crude protein) and isolipidic diets (Table 1) The diets were prepared by weighing the dry ingredients and mixing them thoroughly in a mixer Lipid sources were added drop by drop while the mixture was further blended to ensure homogeneity Approximately 200 ml of hot water was then added for each kg of this mixture The diets were extruded and dried with an electric fan at room temperature for 24 h When feeding was undertaken, the diets were made into small rounded pieces (1.5 cm diameter) to facilitate sucking by the snails All experimental diets were then stored in plastic bags at -20°C until use They were analyzed in duplicate for the proximate compositions according to the standard methods of AOAC (1990) Husbandry conditions Juvenile spotted babylon (Babylonia areolata) were obtained from a commercial private hatchery in Prachuabkirikhan province, Southern Thailand, and maintained in an indoor Table Composition and proximate composition of the experimental diets Ingredients (% dry weight) Basic diet 1% brewers yeast 2% brewers yeast 1% NuProÒ 2% NuProÒ Fishmeal 40.0 40.0 40.0 40.0 40.0 Soybean meal 19.0 18.0 17.0 18.0 17.0 Shrimp meal 3.0 3.0 3.0 3.0 3.0 Wheat flour 17.0 17.0 17.0 17.0 17.0 Wheat gluten 7.0 7.0 7.0 7.0 7.0 Tuna oil 7.0 7.0 7.0 7.0 7.0 Vitamin mixa 2.0 2.0 2.0 2.0 2.0 Mineral mixb 3.0 3.0 3.0 3.0 3.0 b-cellulose 2.0 2.0 2.0 2.0 2.0 Nucleotide (NuProÒ)c – 1.0 2.0 – – Brewers yeastd – – – 1.0 2.0 40.38 Proximate composition (% dry matter) Protein 40.34 40.31 40.19 40.26 Lipid 9.24 9.18 9.25 9.22 9.27 Ash 13.63 13.71 13.58 13.74 13.67 Fiber Moisture 4.75 4.78 4.69 4.79 4.70 11.23 11.17 11.32 11.29 11.27 Gross energy (kcal g-1) a Vitamins (% kg-1 diet): vitamin A 107 IU, vitamin D 106 IU, vitamin E 0.01%, vitamin K 0.001%, vitamin B1 0.0005%, vitamin B6 0.01%, Methionin 0.016% b Minerals (% kg-1 diet): dicalcium phosphate 14.7%, phosphorus 14.7%, manganese oxide 1.0%, copper sulfate 0.36%, iron sulfate 0.20%, potassium iodide 0.10%, cobalt sulfate 0.10%, selenium oxide 0.006% c Alltech Biotechnology Corporation Company, Bangkok, Thailand d Thai Beverage Public Company Limited, Bangkok, Thailand 123 492 Aquacult Int (2011) 19:489–496 hatchery at the Research Unit for Completed Commercial Aquaculture of Spotted Babylon, Chulalongkorn University, Petchaburi province, prior to feeding experiments Homogenous groups of 1,250 juveniles (initial mean body weight of 0.3 ± 0.1 g per snail) were distributed randomly into 25 plastic tanks of 50 30 30 cm at a density of 50 snails per tank Each rearing tank was supplied with a flow-through seawater system with a fixed water flow rate of approximately 150 l/h The bottom of the rearing tank was covered with coarse sand (1.0 cm thickness) as substratum The tanks were provided with a supplemental aerator stone, and water was aerated daily for 20 h to maintain dissolved oxygen levels at or near saturation Water temperature and salinity were controlled at 29–31°C and 30 ppt, respectively A natural photoperiod of 12-h light/ 12-h dark was provided The aquaria and sand substrata were cleaned biweekly to remove excess feed and fecal matter and by scrubbing the sides of the aquarium No chemical or antibiotic agent was used throughout the entire experimental period Feeding trials The basic diet was fed to all snails during a 2-week acclimation period At the beginning of the feeding trials, each diet was fed to five replicate groups of snails for months Snails were hand-fed to apparent visual satiation feeding twice daily (10:00 h and 14:00 h) with one of the experimental diets All groups were fed their respective diets at the same fixed rate of initially 5% of body weight per day The amount of food was adjusted weekly based on the amount of food consumed by snails within 0.5 h the previous day to ensure that only a minimal amount of feed was left Apparent satiation was determined from observation of the point at which snails ceased active feeding, moved away from the feeding area and buried themselves under the sand substratum Uneaten food was siphoned out daily after the snails stopped eating to prevent contamination of the water and sand substratum The amount of food eaten was recorded daily for the calculation of food intake and food conversion ratio Snail performance After the feeding trials, snails in each tank were harvested, counted and weighed Growth performance was determined, and feed utilization was calculated as follows: Weight gainWGị ẳ final weightgị initial weightgị; Specific growth rateSGRị ẳ 100ln Wf ln Wi ị=T; Food conversion ratioFCRị ẳ food intakegị=weight gaingị; Protein efficiency ratio PERị ẳ weight gaingị=protein intakegị; Survival rateSRị ẳ 100 Â ðfinal snail numberÞ=ðinitial snail numberÞ: Bacterial challenge At the end of the experiment, a random sample of snails was taken from each treatment and distributed into three replicate 50-l aquaria of 20 snails each at the time of challenge The water supplied was flow-through dechlorinated seawater at 0.5 l/min maintained at 26 ± 2°C Aeration was supplied via an airblower and airstones The snails were challenged with Vibrio alginolyticus at 106 CFU/ml by intramuscular injection (IM) in the muscular foot For the control group, the snails were intramuscularly injected with 0.1 ml 123 Aquacult Int (2011) 19:489–496 493 of saline solution All groups were kept under observation for days to record clinical asymptomatic signs and daily mortality rates Statistical analysis To determine whether significant differences existed between the different treatments and the parameters tested, all results were analyzed using one-way analysis of variance (ANOVA) Duncan’s multiple range tests were used to compare treatment means Differences were considered significant at P B 0.05 Results After the 4-month feeding trial, significant (P \ 0.05) differences in final weight (FW), weight gain (WG) and specific growth rate (SGR) were observed among snails fed the diets supplemented with brewers yeast or nucleotides (Table 2) The WG of snails fed with diets supplemented with 2% brewers yeast (3.70 g/snail), 1% of nucleotides (3.80 g/snail) and 2% of nucleotides (3.60 g/snail) was significantly higher than that of snails fed the basic diet (3.23 g/snail) and diet supplemented with 1% brewers yeast (3.30 g/snail) The SGR of the snails fed the experimental diets showed a similar trend to WG Survival was not affected by brewers yeast or nucleotide supplementation, and its range was 97.8–99.5% Total food intake was identical in all treatments and ranged from 111 to 117 g food/snail with no significant difference among them Supplementation with brewers yeast and nucleotides improved nutrient utilization Significant (P \ 0.05) differences in FCR and PER were observed among snails fed any of the diets supplemented with brewers yeast and nucleotides (Table 2) The FCR of snails fed the diets supplemented with 2% brewers yeast (1.05), 1% of nucleotides (1.05) and 2% of nucleotides (1.06) was significantly better than that of snails fed the basic diet (1.22) and diet supplemented with 1% brewers yeast (1.22) The PER of snails fed any of the experimental diets showed a similar trend to FCR After days of intramuscular injection with V alginolyticus, significant (P \ 0.05) differences in survival rates were observed among snails fed any of the diets supplemented Table Growth performance of B areolata juveniles fed the experimental diets for months Parameters Diets Basic diet Initial weight (g) Final weight (g) Total feed intake (g) Weight gain (g/snail) Specific growth rate (% day-1) Survival (%) Food conversion ratio Protein efficiency ratio 1% brewers yeast 0.35 ± 0.06a 0.33 ± 0.05a b b 3.57 ± 0.25 a 116.8 ± 6.20 b 3.23 ± 0.31 a 1% NuProÒ 2% brewers yeast 3.60 ± 0.10 a 116.9 ± 5.90 ab 3.30 ± 0.10 ab 4.00 ± 0.36 a 115.4 ± 7.70 ab 3.70 ± 0.36 0.31 ± 0.02a a 4.10 ± 0.20 3.93 ± 0.25ab a 111.2 ± 8.20a a 3.60 ± 0.30a b 117.2 ± 4.70 3.80 ± 0.20 1.99 ± 0.01 2.16 ± 0.08 2.18 ± 0.04 2.14 ± 0.04b 98.90 ± 0.51a 98.9 ± 0.55a 99.5 ± 0.60a 97.8 ± 0.46a 97.8 ± 0.72a a a b b 1.06 ± 0.07b b 2.36 ± 0.09b a 2.06 ± 0.21 1.22 ± 0.07 a 2.06 ± 0.11 b 0.30 ± 0.0a 1.93 ± 0.05 1.22 ± 0.08 ab 0.30 ± 0.01a 2% NuProÒ 1.05 ± 0.06 b 2.39 ± 0.25 1.05 ± 0.06 2.38 ± 0.17 Values are means ± SD Means having the same superscript letters in the same row are significantly different at P \ 0.05 123 494 Aquacult Int (2011) 19:489–496 with brewers yeast and nucleotides (Table 3) Survival of snails fed diets containing brewers yeast or nucleotides was significantly (P \ 0.01) higher than snails fed the basic diet after the same period of months Snails fed diets supplemented with 1% brewers yeast showed the highest survival rate (80.0%), followed by those of snails fed diets supplemented with 1% nucleotides (70.0%), 2% brewers yeast (65.0%) and 2% nucleotides (60.0%), respectively, and snails fed the basal diet showed the lowest survival rate (30.0%) The snails showed typical symptoms of V alginolyticus infection including protruding of the proboscis without retraction, pinkish color at the top of proboscis at the beginning of infection, extreme reddish color and no movement (Fig 1) Discussion In the present study, snails fed diets supplemented with brewers yeast or nucleotides (NuProÒ) exhibited improvement in growth and food utilization compared to those fed the basic diet These results agree with those obtained with Nile tilapia (Abdel-Tawwab et al 2008; Lara-Flores et al 2003), white shrimp (Li et al 2007; Murthy et al 2009), hybrid striped bass (Li and Gatlin 2004) and sea bass (Oliva-Teles and Goncalves 2001) This study is in accordance with the study of Lara-Flores et al (2003) in which the 40% protein diet supplemented with yeast produced the best growth performance and food efficiency of Nile tilapia Oreochromis niloticus, suggesting that yeast is an appropriate growth-stimulating additive in tilapia cultivation The improved snail growth and feed utilization may possibly be due to improved nutrient digestibility In this regard, Lara-Flores et al (2003) found that the addition of live yeast improved diet and protein digestibility, which may explain the better growth and food efficiency seen with yeast supplements Abdel-Tawwab et al (2008) also reported growth-promoting influences of bakers’ yeast, Saccharomyces cerevisiae, on Nile tilapia fry, Oreochromis niloticus Optimal growth, food utilization and protein turnover were obtained with 0.5–1.0 g yeast per kg diet Li and Gatlin (2003) demonstrated that brewers yeast positively influenced growth performance and food efficiency of hybrid striped bass, Morone chrysops M saxatilis, as well as resistance to Streptococcus iniae infection and that brewers yeast can be administered for relatively long periods without causing immunosuppression Li et al (2007) also reported that dietary supplementation of nucleotides at two levels of crude protein diet (25 and 35%) significantly enhanced the final weight of Penaeus vannamei However, additional information is needed in regard to age/size-related responses of the animals as well as the appropriate dose and timing of administration to obtain optimum growth of selected animals In the present study, the snail survival day after IM injection with V alginolyticus showed that Table Survival rate of B areolata juveniles fed a 40% protein diet with different supplementation of brewers yeast and nucleotides in aquarium for months and challenged by V alginolyticus for day Diets Survival rate (%) 30e ± 20.92 Basal diet Ò 70b ± 20.92 Ò 2% NuPro 60d ± 28.50 1% brewers yeast 80a ± 20.92 2% brewers yeast 65c ± 28.50 1% NuPro Treatment means with different superscripts are significantly different (P \ 0.05) 123 Aquacult Int (2011) 19:489–496 495 Fig Mean body weight of B areolata juveniles throughout the 4-month feeding trials snails fed the diets supplemented with 1% brewers yeast had the highest survival rate, followed by those of snails fed diets supplemented with 1% nucleotides, 2% brewers yeast and 2% nucleotides, and that of snails fed the basic diet showed the lowest survival rate (30.0%) These data suggest that the yeast supplementation could increase the non-specific immune system of spotted babylon resulting in a snail resistance to V alginolyticus infection This result agrees with Abdel-Tawwab et al (2008) who evaluated commercial live baker’s yeast S cerevisiae as a immunity promoter for the fry Nile tilapia challenged in situ with Aeromonas hydrophila They found that total fish mortality 10 days after IP injection with A hydrophila decreased with the increased yeast level in fish diets and that the lowest fish mortality was found in fish fed 5.0 g yeast/kg They also indicated that bakers’ yeast supplement is promising as an alternative method to antibiotics for disease prevention in Nile tilapia and that the optimum level of live bakers’ yeast is about 1.0 g per kg diet, corresponding to this study in that the best result for V alginolyticus resistance was found in snails fed with 1% of brewers yeast per kg diet It is possible that the negative effect on survival of B areolata, found for nucleotides in this study, could be due to the dose administered, especially when taking into account that the brewers yeast diets gave relative better survival, though not at a significant level These findings suggest that there is need for caution when administering nucleotides long term and/or in high dose Shelby et al (2009)observed that protection from disease challenge by pasteurellosis caused by Photobacterium damselae in gilthead seabream was dependent on duration and dose For example, fish fed glucans for weeks had no protection from disease challenge at the higher inclusion rates of glucan Scholz et al (1999) also reported that Atlantic salmon fry, fed a diet containing baker’s yeast at 2%, displayed better survival than control animals when challenged with Vibrio anguillarum, while juvenile European seabass showed similar results when fed a diet containing experimental treated yeast at 1% Furthermore, brewers yeast chemically treated to enhance its digestibility and to increase access to the glucan on the surface of the yeast gave better survival than fresh yeast However, further research is needed as there are numerous gaps in existing knowledge about exogenous nucleotides and brewers yeast application to spotted babylon including various aspects of digestion, 123 496 Aquacult Int (2011) 19:489–496 absorption, metabolism and influences on various physiological responses especially expression of immunogenes and modulation of immunoglobin production In conclusion, this study represents the first attempts to utilize the by-product of brewers industry, brewers yeast, supplemented in feed as the protein source The results of this trial indicate that brewers yeast provided the good results in growth and feed efficiency, with no negative effects in spotted babylon juvenile performance (growth, survival and disease resistance) Moreover, the inclusion of up to 2% brewers yeast in the diet improved feed efficiency and protein utilization Based on the result of this study, it is concluded that brewers yeast positively influenced growth performance and feed efficiency of spotted babylon as well as resistance to V alginolyticus infection In addition, brewers yeast can be administered in the feeds as the alternative, less expensive protein source for this species Acknowledgments This study was supported by the National Research Council of Thailand (NRCT), who provided funding for this research in the fiscal years 2005–2008 We are especially grateful to Associate Professor Dr Somkiat Piyatiratitivorakul, Faculty of Science, Chulalongkorn University, and Professor Dr Yutaka Natsukari, Faculty of Fisheries, Nagasaki University for their encouragement, suggestions and critical reading of the manuscript References Abdel-Tawwab M, Abdel-Rahman AM, Ismeal NEM (2008) Evaluation of commercial live baker yeast (Saccharomyces cerevisiae) as a growth and immunity promoter for Fry Nile tilapia Oreochromis niloticus (L.) challenged in situ with Aeromonas hydrophila Aquaculture 280:185–189 Chaitanawisuti N, Kritsanapuntu A (1999) Growth and production of hatchery-reared juvenile spotted babylon, Babylonia areolata Link 1807, cultured to marketable sizes in intensive flow-through and semi-closed recirculating water system Aquacult Res 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yeast and the prebiotic Grobiotic AE influence growth performance, immune responses and resistance of hybrid striped bass (Morone chrysops M saxatilis) to Streptococcus inniae infection Aquaculture 231:445–456 Li P, Gatlin DM (2006) Nucleotide nutrition in fish: current knowledge and future applications Aquaculture 251:141–152 Li P, Burr GS, Goff J, Whiteman KW, Davis KB, Vega RR, Neill WH, Gatlin DM (2005) A preliminary study on the effects of dietary supplementation of brewers yeast and nucleotides, singularly or in combination, on juvenile red drum (Sciaenops ocellatus) Aquacult Res 36:1120–1127 Li P, Lawrence A, Castille FL, Gatlin DM (2007) Preliminary evaluation of a purified nucleotide mixture as dietary supplement for Pacific white shrimp (Litopenaeus vannamei) Aquacult Res 38:887–890 Murthy HS, Li P, Lawrence AL, Gatlin DM (2009) Dietary b-glucan and nucleotide effects on growth, survival and immune responses of Pacific white shrimp, Litopenaeus vannamei J Appl Aquacult 21:160–168 Oliva-Teles A, Goncalves P (2001) Partial replacement of fishmeal by brewers yeast (Saccharomyces cerevisiae) in the diets for sea bass (Dicentrarchus labrax) juveniles Aquaculture 202:269–278 Scholz U, Diaz GG, Ricque D, Cruz Suarez LE, Albores FV, Latchford J (1999) Enhancement of vibriosis resistance in juvenile Penaeus vannamei by supplementation of diets with different yeast products Aquaculture 176:271–283 Shelby RA, Lim C, Aksoy MY, Welker TL, Klesius PH (2009) Effects of yeast oligosaccharide diet supplements on growth and disease resistance in juvenile Nile tilapia Oreochromis niloticus J Appl Aquacult 21:61–71 123 ... Burr GS, Goff J, Whiteman KW, Davis KB, Vega RR, Neill WH, Gatlin DM (2005) A preliminary study on the effects of dietary supplementation of brewers yeast and nucleotides, singularly or in combination,... fixed rate of initially 5% of body weight per day The amount of food was adjusted weekly based on the amount of food consumed by snails within 0.5 h the previous day to ensure that only a minimal... benefit of the dietary supplementation has not been evaluated for the Babylonia areolata Therefore, this study was conducted to determine the effects of brewers yeast and nucleotide supplementation