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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Improving Disease Resistance for Shrimp Through Application of Probiotics in Feed

Choi, Moonyoung 12 June 2015 (has links)
Diseases affecting shrimp contribute to billions of dollars of economic loss yearly to the aquaculture industry. Recently, one of the primary causative agents of disease has been Vibrio parahaemolyticus; in 2009, a new strain causing Early Mortality Syndrome (EMS) or acute hepatopancreatic necrosis disease (AHPND) in shrimp emerged. Shrimp losses attributed to pathogens can be greatly reduced through probiotic use, which are known to act as natural immune enhancers and promote pathogen resistance. However, research on probiotic treatment against EMS disease is lacking. The overall project goal was to improve intensive shrimp production through direct application of probiotics in aquaculture feeds. The value of probiotics for the shrimp industry was evaluated by (1) reducing severity or mortality of V. parahaemolyticus disease in shrimp, (2) qPCR confirmation of Bacillus spore germination in shrimp gut, and (3) probiotic effectiveness evaluation for improving disease resistance. The virulence of several Vibrio spp. strains was examined and it was concluded the V. parahaemolyticus strain identified as the causative agent of EMS was the most lethal; EMS-infected shrimp exhibited 100% mortality within 36-hours of feed inoculation. The number of bacterial cells added to feed directly correlated with pathogenicity and only cells, not filtrate, was capable of causing death. Probiotic strains were evaluated and it was concluded that probiotic strains A, A/B blend, and B were the best candidates for promoting disease resistance against EMS. This research will provide the shrimp farming industry with information vital to developing a means for reducing economic loss from Vibrio-infected shrimp. / Master of Science in Life Sciences
2

Desempenho zoot?cnico dos camar?es: Litopenaeus vannamei e Macrobrachium rosenbergii em tanques rede e aquicultura familiar na comunidade de Bebida-Velha, RN / Performance of shrimps Litopenaeus vannamei livestock Macrobrachium rosenbergii in cages and aquaculture family in Bebida Velha community, RN

Medeiros, Priscila Maria Oliveira Campos 10 February 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-10T00:14:52Z No. of bitstreams: 1 PriscilaMariaOliveiraCamposMedeiros_DISSERT.pdf: 1682569 bytes, checksum: 4c9914ef6bdc76ec09d3b21d2a0a8622 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-16T21:20:13Z (GMT) No. of bitstreams: 1 PriscilaMariaOliveiraCamposMedeiros_DISSERT.pdf: 1682569 bytes, checksum: 4c9914ef6bdc76ec09d3b21d2a0a8622 (MD5) / Made available in DSpace on 2016-03-16T21:20:13Z (GMT). No. of bitstreams: 1 PriscilaMariaOliveiraCamposMedeiros_DISSERT.pdf: 1682569 bytes, checksum: 4c9914ef6bdc76ec09d3b21d2a0a8622 (MD5) Previous issue date: 2015-02-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O estudo visa avaliar o desempenho zoot?cnico e identificar as les?es das intera??es agon?sticas do camar?o Macrobrachium rosenbergii em diferentes densidades em tanques rede (cap?tulo 1); comparar o desempenho zoot?cnico dos M. rosenbergii e Litopenaeus vannamei em tanques rede (cap?tulo 2); al?m de conhecer os saberes e fazeres de uma comunidade tradicional de aquicultores de Bebida-Velha, no munic?pio de Pureza/RN, que praticam a aquicultura rural e familiar, bem como tra?ar o perfil socioecon?mico da comunidade e avaliar o manejo que estes aquicultores utilizam no cultivo de camar?es M. rosenbergii (cap?tulo 3). Para realizar os experimentos (cap?tulo 1 e 2) os camar?es das esp?cies L. vannamei e M. rosenbergii foram pesados em balan?a digital e transferidos a cultivos em tanques rede. Os tanques rede possu?am 1m?, com malha de 5 mm entre n?s e foram fechados em cima com tela para evitar a a??o de predadores (aves, insetos). Os animais permaneceram em adapta??o por quinze dias antes do in?cio da coleta de dados (de cada experimento). Os dois experimentos duraram setenta dias, totalizando oitenta e cinco dias de cultivo. Durante os cultivos, os animais foram alimentados com ra??o peletizada para camar?o em 10% da sua biomassa, com 35% de prote?na bruta, ofertada em bandejas de alimenta??o duas vezes por dia nos hor?rios (7:00 h e 14:00 h). A sobra na bandeja foi retirada ap?s 2h de perman?ncia para calcularmos o consumo. Para determinar os par?metros zoot?cnicos, biometrias foram realizadas a cada 10 dias. Os resultados dos dois experimentos foram analisados atrav?s do programa STATISTIC 7.0 (2004). No experimento do cap?tulo 1 foram aplicados 5 tratamentos, com 5 repeti??es cada: D5 - 5 animais/m2 ; D10 - 10 animais/m2 ; D15 - 15 animais/m2 ; D20 - 20 animais/m2 e D25 - 25 animais/m2 . Para isso, 25 tanques rede foram distribu?dos aleatoriamente em 2 viveiros de alvenaria. No final do experimento as les?es foram verificadas e quantificadas. O experimento do cap?tulo 2 teve in?cio quando os camar?es alcan?aram a mesma idade (oitenta e quatro dias) e foi utilizado a densidade de 25 camar?es/m2 com 4 repeti??es. Para a realiza??o do cap?tulo 3, foram aplicadas entrevistas semi-estruturadas atrav?s de abordagem direta dos assentados de Bebida Velha praticantes da atividade de aquicultura, produtores de til?pia e camar?o da comunidade. Os dados coletados foram tabulados e analisados de acordo com as respostas obtidas pelos participantes. Portanto, foi constatado que a quantidade de les?es aumentou com o aumento 7 da densidade de estocagem e que a densidade de 10 camar?es de ?gua doce/m? apresentou as melhores condi??es para obter um melhor desempenho em tanques rede. O cultivo em tanques rede da esp?cie de camar?o de ?gua doce M. rosenbergii teve melhores ?ndices zoot?cnicos do que o cultivo da esp?cie de camar?o marinho L. vannamei. Foi poss?vel verificar que as atividades das quais os entrevistados praticam, garantem uma boa qualidade de vida e renda para eles, al?m disso, os entrevistados possuem conhecimento tradicional do saber e fazer, e tamb?m se mostram interessados no cultivo da esp?cie M. rosenbergii. / The study aims to evaluate the performance and identify lesions of agonistic interactions of Macrobrachium rosenbergii in different densities cages (chapter 1); compare the growth performance of shrimp M. rosenbergii and Litopenaus vannamei cages (chatper 2); in addition the study aimed at identifying the knowledge and practices of a traditional community of farmers Bebida-Velha, in the city of Pureza / RN, practicing rural family and aquaculture, as well as tracing the community socioeconomic profile and evaluate the management that these farmers use in shrimp farming Macrobrachium rosenbergii (chapter 3). To perform the experiments (chapter 1 and 2) shrimp species L. vannamei and M. rosenbergii were weighed on a digital scale and transferred to cultures in cages. The cages had 1m?, with 5mm mesh between us and were closed on top with screen to avoid predators (birds, insects). The animals remained in adaptation for fifteen days before the start of data collection (each experiment). Both experiments lasted seventy days, totaling eighty-five days cultivation. During the cultures, animals were fed pelleted feed for shrimp at 10% of their biomass with 35% crude protein, offered in feed trays twice a day during the hours (7:00 am and 14:00 pm). The remnants in the tray were removed after 2h of permanence to calculate intake. To determine the performance parameters, some samples were taken every 10 days. The results of both experiments were analyzed using the STATISTIC 7.0 (2004). In Chapter 1 experiment were applied5 treatments were applied with 5 replications each: D5 - 5 animals/m2 ; D10 - 10 animals/m2 ; D15 - 15 animals/m2 ; D20 - 20 animals/m2 ; D25 - 25 animals/m2 . To this, were distributed 25 cages randomly in two masonry nurseries. The end of the experiment the lesions were verified and quantified. The chapter 2 experiment began when the shrimp reached the same age (eighty-four days) and was used the density of 25 shrimp / m2 with 4 repetitions. For the realization of chapter 3 were applied semi-structured interviews by direct approach of Bebida Velha of settlers practicing aquaculture activity, tilapia producers and community shrimp. Data were tabulated and analyzed according to the responses obtained by the participants. Therefore, the amount of damage increased with increasing stocking density. The density of 10 freshwater shrimp/m? showed the best conditions for a better performance in cages. It can be concluded that in cages, the cultivation of species of fresh water shrimp M. rosenbergii had better zootechnical indexes than the cultivation of marine shrimp species L. 9 vannamei. It was possible to verify that the activities of which the interviewees practice guarantee a good quality of life and income for them. We find that respondents have traditional and local knowledge, and also may be interested in the cultivation of the species M. rosenbergii.

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