• Title, Summary, Keyword: Feeding Strategy

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Feeding Habits of Daggertooth Pike Conger Muraenesox cinereus in the Coastal Water off Goseong, Korea (경남 고성 주변해역에서 출현하는 갯장어(Muraenesox cinereus)의 식성)

  • An, Young-Su;Park, Joo-Myun;Kim, Hyeon-Ji;Baeck, Gun-Wook
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.1
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    • pp.76-81
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    • 2012
  • The feeding habits of daggertooth pike conger Muraenesox cinereus were studied using 380 specimens collected in the coastal waters off Goseong, Korea, from June to September, 2011. The M. cinereus ranged from 10.0-23.7 cm in anal length (AL). M. cinereus is a piscivore that consumes mainly fish. Engraulis japonicus was the preferred prey, but its diet also included small numbers of crabs, shrimps, cephalopods, and bivalves. The feeding strategy graphical method revealed that M. cinereus is a specialized feeder with a narrow niche width. All size classes of M. cinereus consumed fish and M. cinereus did not show significant ontogenetic changes in feeding habits. The diet overlap index between size classes was >0.96, indicating high diet similarities. The prey size increased significantly with M. cinereus size.

Nutritional Factors Affecting Abdominal Fat Deposition in Poultry: A Review

  • Fouad, A.M.;El-Senousey, H.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.7
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    • pp.1057-1068
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    • 2014
  • The major goals of the poultry industry are to increase the carcass yield and to reduce carcass fatness, mainly the abdominal fat pad. The increase in poultry meat consumption has guided the selection process toward fast-growing broilers with a reduced feed conversion ratio. Intensive selection has led to great improvements in economic traits such as body weight gain, feed efficiency, and breast yield to meet the demands of consumers, but modern commercial chickens exhibit excessive fat accumulation in the abdomen area. However, dietary composition and feeding strategies may offer practical and efficient solutions for reducing body fat deposition in modern poultry strains. Thus, the regulation of lipid metabolism to reduce the abdominal fat content based on dietary composition and feeding strategy, as well as elucidating their effects on the key enzymes associated with lipid metabolism, could facilitate the production of lean meat and help to understand the fat-lowering effects of diet and different feeding strategies.

Influence of Food Allowance on Nutrient Utilization of Oat (Avena sativa) Hay by Goats and Feeding Value of Leftovers from High Levels of Offer in Sheep

  • Dutta, N.;Sharma, K.;Hasan, Q.Z.;Pathak, N.N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.5
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    • pp.723-727
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    • 1999
  • Two experiments were conducted to determine the effect of feeding levels on intake and nutrient utilization of oat (Avena sativa) hay (OH) by goats and potential feeding value of leftovers from high levels of offer in sheep. In experiment 1, the goats (15) were offered OH at three levels of feeding to give leftovers of about 20% (T-1), 35% (T-2) and 50% (T-3) of DM offered. A marked effect of refusal rate of OH on intake and digestibility of nutrients was evident. Allowing selective consumption at higher levels (T-2 and T-3), the intake of DCP and TDN from OH was found not only to meet the maintenance requirement but provided surplus nutrients for moderate production. In experiment 2, Sheep (3) were offered one of the three dietary treatments viz OH, refusals left uneaten by goats in T-2 and T-3 (OHR) and 3% urea treated oat hay refusals (UTR) in a $3{\times}3$ latin square design. Though the potential feeding value of leftovers (OHR and UTR) was lower than OH, the results confirm the possibility of their effective use. It was concluded that feeding above the conventional ad libitum level could be an alternative to improve the performance of ruminants fed feeds like oat hay. The potential impact of the strategy would, however, depend on the effective reutilization of leftovers for feeding other animals.

Feeding Ecology of the White-spotted Conger Eel(Conger myriaster) in the Southern Sea of Korea (한국 남해 연안에 분포하는 붕장어(Conger myriaster)의 섭이생태)

  • Choi, Jung-Hwa;Choi, Sung-Hee;Kim, Jong-Bin;Park, Jeong-Ho;Oh, Chul-Woong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.4
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    • pp.282-288
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    • 2008
  • Feeding ecology of the white-spotted conger eel Conger myriaster in the Southern Sea of Korea was examined. Specimens were caught monthly from January 2004 to December 2006. Primary prey items of C. myriaster included fish, shrimp, and crabs. C. myriaster exhibited a nocturnal feeding strategy and preyed upon a wide range of pelagic fish groups(e.g., Engraulis japonicus, Glossanodon semifasciatus, and Maurolicus muelleri). This species was also an opportunistic feeder that exploited the available prey in each area(i.e., fish in the A area and shrimp in the B area). The composition of the diet of C. myriaster exhibited seasonal fluctuations that were related to food availability during each season. The observed ontogenetic shifts in diet were relatively clear, despite substantial overlap between the 10 cm and 20 cm groups of C. myriaster.

Diet composition and feeding strategy of John Dory, Zeus faber, in the coastal waters of Korea

  • Kim, Han Ju;Kim, Hyeong-Gi;Oh, Chul-Woong
    • Journal of Ecology and Environment
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    • v.44 no.1
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    • pp.54-61
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    • 2020
  • Background: Most fish undergo prey switch from juvenile to adult. It is thought that slightly different feeding habits occur among adult fishes due to growth, spawning, habitat change, and so on. Therefore, the diet of the John Dory Zeus faber (≥ 24 cm TL) was studied in the coastal waters of Korea by analysis of stomach contents, with comparison by season and size class of diet composition and prey diversity. Monthly samples were taken from February 2017 to January 2018. Results: The results showed that the John Dory was a piscivorous predator, and pisces had occupied 82.3% of IRI%. Trichiurus lepturus and Trachurus japonicus were important preys in all size classes and seasons. Diet composition differed among the size classes and seasons (Chi-square test, P < 0.05). As body size of Z. faber increased, the occurrence of benthic fish (Glyptocephalus stelleri) tended to increase. The seasonal prey composition also changed depending on the abundant species of each season. Conclusions: Z. faber is a piscivorous predator. The consumption habits of Z. faber appear to different results by their size and seasons. This study suggests that Z. faber could be considered an opportunistic predator.

Control of Glucose Concentration in a Fed-Batch Cultivation of Scutellaria baicalensis G. Plant Cells a Self-Organizing Fuzzy Logic Controller

  • Choi, Jeong-Woo;Cho, Jin-Man;Kim, Young-Kee;Park, Soo-Yong;Kim, Ik-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.11 no.5
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    • pp.739-748
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    • 2001
  • A self-organizing fuzzy logic controller using a genetic algorithm is described, which controlled the glucose concentration for the enhancement of flavonoid production in a fed-batch cultivation of Scutellaria baicalensis G. plant cells. The substrate feeding strategy in a fed-batch culture was to increase the flavonoid production by using the proposed kinetic model. For the two-stage culture, the substrate feeding strategy consisted of a first period with 28 g/I of glucose to promote cell growth, followed by a second period with 5 g/I of glucose to promote flavonoid production. A simple fuzzy logic controller and the self-organizing fuzzy logic controller using a genetic algorithm was constructed to control the glucose concentration in a fed-batch culture. The designed fuzzy logic controllers were applied to maintain the glucose concentration at given set-points of the two-stage culture in fed-batch cultivation. The experimental results showed that the self-organizing fuzzy logic controller improved the controller\`s performance, compared with that of the simple fuzzy logic controller. The specific production yield and productivity of flavonoids in the two-stage culture were higher than those in the batch culture.

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Cloning, Characterization of Pichia etchellsii $\beta-Glucosidase$ II and Effect of Media Composition and Feeding Strategy on its Production in a Bioreactor

  • Sethi Benu;Jain Monika;Chowdhary Manish;Soni Yogesh;Bhatia Yukti;Sahai Vikram;Mishra Saroj
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.1
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    • pp.43-51
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    • 2002
  • The cloning and expression of $\beta-glucosidase$ II, encoded by the gene ${\beta}glu2$, from thermotolerant yeast Pichia etchellsii into Escherichia coli is described. Cloning of the 7.3 kb BamHI/SalI yeast insert containing ${\beta}glu2$ in pUC18, which allowed for reverse orientation of the insert, resulted in better enzyme expression. Transformation of this plasmid into E. coli JM109 resulted in accumulation of the enzyme in periplasmic space. At $50^{\circ}C$, the highest hydrolytic activity of 1686 IU/g protein was obtained on sophorose. Batch and fed-batch techniques were employed for enzyme production in a 14 L bioreactor. Exponential feeding rates were determined from mass balance equations and these were employed to control specific growth rate and in turn maximize cell growth and enzyme production. Media optimization coupled with this strategy resulted in increased enzyme units of 1.2 kU/L at a stabilized growth rate of $0.14\;h^{-l}$. Increased enzyme production in bioreactor was accompanied by formation of inclusion bodies.

Effects of Alternate-Week Feeding Strategies on Growth and Feed Efficiency Ratio of Juvenile Nile Tilapia Oreochromis niloticus in a Recirculating System

  • Cho, Sung-Hwoan
    • Fisheries and aquatic sciences
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    • v.8 no.3
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    • pp.128-131
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    • 2005
  • The effects of alternate-week feeding strategies on growth and feed efficiency ratio of juvenile Nile tilapia were investigated in a recirculating aquaculture system. Twenty fish initially weighing 25.5 g were randomly distributed into each of 18 tanks to conduct three replicates for each of six different feeding strategies. Weight gain of fish in the control that were fed daily for 6-week feeding trial was significantly higher than those of fish subjected to various alternate-week feeding regimes. Weight gain of fish that were starved for 3 weeks and then fed daily for 3 weeks (3WS+3WF) was not significantly different from that of fish, starved and fed daily for alternate 1-week period during the trial (1WS+1WF), but was significantly higher than those of fish starved for 2 weeks, and fed for 2 weeks (2WS+2WF); fish starved for 4 weeks and fed for 2 weeks (4WS+2WF); and fish fed for 5 weeks and fed for 1 week (5WS+1WF.) The amount of feed supplied to fish in the groups of 1WS+1WF and 3WS+3WF was significantly lower than that fed to fish in the control group, but significantly higher than the amount feed supplied to fish in the other three groups. Feed efficiency ratio for fish in the control group did not differ from that for fish in the groups of 1WS+1WF, 2WS+2WF and 3WS+3WF, but was significantly higher than that for fish in the groups of 4WS+2WF and 5WS+1WF. In conclusion, juvenile Nile tilapia that were subject to starvation for 1 to 5 weeks did not exhibit compensatory growth sufficient to attain the same weight as fish fed daily for 6 weeks. In addition, fish subjected to starvation exhibited low feed efficiency ratio compared to fish fed daily, which were probably attributable to poor weight gain.

Feeding Habits of the Marbled Flounder, Peluronectes yokohamae in the Coastal Waters off Tongyeong, Korea (통영주변해역에 서식하는 문치가자미(Pleuronectes yokohamae)의 식성)

  • Huh, Sung-Hoi;Nam, Ki-Mun;Park, Joo-Myun;Jeong, Jae-Mook;Baeck, Gun-Wook
    • Korean Journal of Ichthyology
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    • v.24 no.2
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    • pp.77-83
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    • 2012
  • The feeding habits of the marbled flounder Pleuronectes yokohamae were studied using 395 specimens collected from January to December, 2010, in the coastal waters off Tongyeong, Korea. The size of P. yokohamae ranged from 10.5 to 38.8 cm in standard length (SL). P. yokohamae is a bottom-feeding carnivore that consumes mainly bivalves, amphipods and polychaetes. Its diet also includes small quantities nemertians, anthozoan, isopods, copepods, tanaidacean, shrimps, crabs and ophiuroids. Our feeding-strategy graphical method reveled that P. yokohamae was a generalized feeder, with a wide niche width. P. yokohamae mainly consumed bivalves, amphipods and polychaetes, and did not show significant ontogenetic changes in feeding habit without size over 22 cm. Prey size did not increase significantly as growing fish size.

Optimal Strategy for Ethanol Production in Repeated Fed-batch Operation Using Flocculent Sacchromyces cerevisiae (응집성 Sacchromyces cerevisiae 를 이용한 반복 유가식 ethanol 생산에서의 최적 운전전략)

  • Lee, Sang-Eun;Yeon, Ji-Hyeon;Seo, Yong-Chang;Kang, Do-Hyung;Lee, Hyeon-Yong;Jung, Kyung-Hwan
    • KSBB Journal
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    • v.25 no.2
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    • pp.179-186
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    • 2010
  • We investigated the optimal strategy for ethanol production using flocculent Sacchromyces cerevisiae ATCC 96581. Considering the characteristic of flocculent yeast, a repeated fed-batch ethanol fermentation was designed, in which non-sterile glucose powder was fed every 12 hours and, after cell flocculation, new feeding medium was exchanged every 24 or 36 hours. We particularly compared this fermentation process with those when cell flocculation was not carried out. Finally, the maximal total ethanol production was 825 g-ethanol during 120 hours, in which the time interval of withdrawal-fill of feeding medium was 24 hours and cell flocculation was carried out.