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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

An investigation into the dietary requirements of Oreochromis Mossambicus fry and the formulation and preparation of a dry food for use in aquaculture

Thorpe, Peter Stuart January 1989 (has links)
The need for developing a dry feed which satisfied the nutrient requirements of Oreochromis mossambicus fry was identified. The spawning and grading techniques which resulted in a higher fecundity and ensured uniformity within and between samples of fry are discussed. Preparation techniques were developed which met the physical requirements of fry feeds. An analysis of the flesh and yolk sac fry for amino acid composition was undertaken. The initial test diet was based on these results, as well as on the natural feeding ecology of the species. Feeding trials were undertaken and growth responses monitored to determine the optimum levels of the various dietary components. A feed was developed which gave superior growth to that obtained with natural food organisms. This feed consisted of Torula yeast (47%), Weider Super Protein (44.39%), Vitamin supplement (0.45% - multivitamin), additional vitamin C supplement (0.16%), Spirulina (5%), and methionine supplement (3%). An optimum particle size range for O. mossambicus fry (between 5 & 25mm) was established at 125-200um. The fry should be fed the following feed ratios depending on age: 30.4% body weight/day up to day 5, 30.6% body weight/day up to day 10 and 25.1% body weight/day up to day 15. An optimum feeding frequency of 8/10hr day was recommended. A feed conversion ratio of 1.24:1 and a protein efficiency ratio of 0.682:1 was obtained. Digestable energy of the feed was determined at 16.1 kj/g feed. The established dry feed is suitable for use in commercial hatcheries, and as a formulation for further research on the intensive rearing of O. mossambicus fry.
2

The development of tilapia feeds based on locally available materials in Zambia

Dickson, Malcolm January 1989 (has links)
Nakambala Tilapia Farm commenced operations at the Nakambala Estate of the Zambia Sugar Company near Mazabuka, Zambia in early 1982. The farm used an intensive tank system designed to produce 50 tonnes of tilaplas per annum to provide fish for feeding the labour force on the sugar estate. The project had to manufacture fish feeds on site. A wide range of feed raw materials were used over the course of the project, with formulations designed to aim to supply the nutrient levels suggested by the University of St iIng, Institute of Aquaculture. The raw materials included microalgae from a pilot scale algae culture project funded by the Overseas Development Administration, dried fish, blood meal, carcase meal, soyabeans, cottonseed, hydrolysed feather meal, sunflower oilcake, lucerne, leucaena, yeast, wheatings and maize. Dis involved identification of raw material supplies, development of appropriate feed processing methods, formulation of feeds and manufacture of the feeds. Seventeen feed trials were carried out to evaluatet he use of different feed formulations. Many of these trials concentrated on the supply of vitamins in the feeds as the provision of a vitamin supplement was made impossible by restrictions on foreign exchange allocations. The main conclusions were 1. The poor financial performance of the farm in the initial years of operation was due to problems in project implementation, particularly the absence at the start of the project of a breeding population of tilaplas of a species with proven growth potential in an intensive system. 2. The feeds being produced by 1985 were adequate to sustain good growth in tilapias. Feed trials had shown that there was no need to use a vitamin supplement in the feeds despite advice to the contrary from other authorities. 3. The farming system utilised was appropriate to Zambian conditions, despite being extremely intensive.
3

The effect of dietary L-carntine [i.e. carnitine] supplementation on production performance parameters of Mozambique tilapia, Oreochromis mossambicus, at sub-optimal water temperature

Tekle, Esayas Welday 12 1900 (has links)
Thesis (MPhil)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: 60-day growth experiment was conducted to investigate the effect of dietary Lcarnitine supplementation on the production performance parameters of Mozambique tilapia, Oreochromis mosambicus. A number of approximately 140 tilapia fry with average weight of l.4g ± 0.71g were stocked in each of 40 fine-meshed hapas (I mx 1mx 1.5m) submerged within a complete recirculation pond system. During the first 30 days of the experiment water temperatures ranged from 19 to 23°C where after it decreased to 16-20°C for the consecutive 30-day period. Dietary treatments consisted of 8 replicates of 5 levels of L-carnitine supplementation labelled as Co, C250,C500, C750 and C 1000represented Omg, 250mg, 500mg, 750mg and 1000mg L-carnitine supplementation per kg feed respectively. Results were analyzed for significant differences using one-way analysis of variance (ANOVA) and Tukey's pairwise comparison test for growth rate, feed intake (FI) and feed conversion efficiency. After completion of the trial 8 fish from each hapa were sacrificed and analyzed for cephalosomatic index (CSI), dress out percentage (viscera, gills and head excluded), viscerosomatic index (VSI) and hepatosomatic index (HSl). Poor production performance results were generally observed as water temperatures were sub-optimal, especially during the second 30-days period. Results from the trial indicate no significant differences (P>0.05) between treatments for weight gain, FCR, FI and VS!. A negative trend was observed for FCR with increasing level of L-carnitine supplementation for both the first 30-day period (1.50±0.07, 1.53±0.08, 1.58±0.09 and 1.61±0.17 for C250,C50Q,C750and C 1000)as well as for the consecutive lower temperature 30-day period (2.22±0.10, 2.25±0.ll, 2.27±0.28 and 2.29±0.2l for C250, C500, C750 and C 10(0)'Although statistically not significant, fish fed the C250showed better performance in dress out percentage weight either than the control or the higher levels. The increasing trend for head weight with increasing level of L-carnitine supplementation were significant (P<0.05) from Co and C250with and above C500.The decreasing trend for liver weight with increasing level of L-carnitine supplementation became significant (P<0.05) with and above C750.The results of the current study showed a trend in the improvement of L-carnitine on the production performance parameters. However, the natural content of L-carnitine in the basal diet impaired with the inclusion levels, thus further research at lower inclusion levels is recommended. / AFRIKAANSE OPSOMMING: 'n Proef oor 'n tydperk van 60-dae is onderneem om die effek van L-karniten aanvulling op produksie prestasie parameters van Mosambiek tilapia (0. mosambicusi te ondersoek. 140 tilapia vingerlinge met 'n gemiddelde massa van lAg ± 0.7lg is ewekansig uitgeplaas in 40 eksperimentele hapa-hokkies (lmxlmx1.5m) in "n hersirkulasie sementdam-stelsel. Gedurende die eerste 30 dae van die proef het water temperatuur gewissel tussen 19 to 23°C waarna dit gedaal het na tussen l6-20°C vir die opeenvolgende 30-dag periode. Proef-rantsoen behandelings het bestaan uit 8 herhalings van 5 vlakke van L-karnitien aanvulling, naamlik Co,C250, C500, C750 en CIOOOvir Omg, 250mg, 500mg, 750mg en 1000mg L-karnitien aanvulling per kg voer afsonderlik. Resultate was ontleed vir betekenisvolle verskille deur gebruik te maak van analise van variansie (ANOVA) ontleding en die Tukey se vergelykende toets vir groeitempo, voerinname en voeromsettingsverhouding. Aan die einde van die proefperiode is 8 visse van elke hapa ontleed vir liggaamskomponent-samestelling (kop-, ingewande- en hepatosomatiese indekse. Ondergemiddelde produksie resultate is waargeneem wat toegeskryf kan word aan onder-optimale water temperature, veral gedurende die tweede 30-dag periode van die proef. Proef resultate het geen betekenisvolle verskille (P>0.05) in massatoename, voeromsettingsverhouding (VOV) of visserosomatiese indeks tussen behandelings getoon nie. 'n Negatiewe neiging is waargeneem vir VOV met toenemende vlakke van L-kamitien insluiting vir beide die eerste 30 dag periode (1.50±0.07, 1.53±0.08, 1.58±0.09 and 1.61±0.17 for C250, C500, C750 and CIOOO) sowel as vir die opvolgende 30-day periode nie (2.22±0.10, 2.25±0.11, 2.27±0.28 and 2.29±0.21 for C250, C50o, C750 and CIOOO). 'n Toenemende neiging vir kop-massa met toenemende L-kamitien insluiting was betekenisvol (P<0.05) vanaf Co en C250 met en hoër as C500. 'n Dalende neiging vir lewermassa met toenemde L-kinsluiting was betekenisvol (P<0.05) met en hoër as C750. Resultate van die proef dui oor die algemeen op 'n neiging tot verbeterde produksie prestasie parameters van tilapia vingerlinge met toenemde insluiting van Lkamitien. Verdere navorsing word aanbeveel om die invloed van natuurlike Lkamitien in die proteïen-bronne van die basaalrantsoen te op die gebrek aan betekenisvolheid van hierdie neiging te verklaar.
4

Proteína e energia digestíveis e colina para Tilápia-do-Nilo: desempenho e respostas fisiológicas em condições de estresse

Fernandes Junior, Ademir Calvo [UNESP] 20 July 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-20Bitstream added on 2014-06-13T19:04:44Z : No. of bitstreams: 1 fernandesjunior_ac_dr_botfmvz.pdf: 887510 bytes, checksum: 64f9b26203c2641b6d0ad41999a7714d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / Pesquisas para determinar a exigência em proteína e energia digestíveis e colina simultaneamente são excassas. Este estudo avaliou o efeito da proteína e energia digestíveis e colina no desempenho produtivo e nas respostas fisiológicas da tilápia-do-Nilo. Juvenis (87,0 ± 7,0 g), identificados individualmente com micro-chipe foram distribuídos em 40 aquários de 250L (8 peixes/aquário) utilizando um delineamento experimental inteiramente casualizado com 20 tratamentos em esquema fatorial 5x2x2 e 16 repetições: 24,0; 26,0; 28,0; 30,0 e 32,0% proteína digestível, 3200 e 3500 kcal kg-1 energia digestível e 0,0 e 1000,0 mg colina kg-1. Foram determinados parâmetros de desempenho produtivo, índice hepatossomático, gordura visceral, além das respostas fisiológicas antes e após estímulo a quente. A dieta suplementada com colina melhorou a conversão alimentar aparente; os peixes alimentados com dieta com 32,0% PD tiveram menores IHS e GV e a dieta com 3500 kcal ED kg-1 determinou melhores condições de saúde após estresse, enquanto que os peixes alimentados com dieta com 32,0% PD com 3500 kcal ED kg-1, e suplementada com colina determinou melhor desempenho produtivo e higidez dos peixes / Researche effects aimed at determing digestible energy, protein and choline requirement simultaneous by are scarce. This study evaluated effects of digestible protein, digestible energy and choline in the physiological response and growth performance of Nile tilapia. Juveniles (87.0 ± 7.0 g), individualy taged Nile tilapia (Animaltag®) were randomly distributed into 40, 250-L 8 fish per tank seting up a totally randomized trial, 5x2x2 factorial arrangement, with twenty treatments (n=2): 24.0; 26.0; 28.0; 30.0 and 32.0% digestible protein, 3200 and 3500 kcal kg-1 digestible energy and 0.0 and 1000 mg choline kg-1 diet. Growth performance, hepatosomatic index, visceral fat and physiological response before and after heat stress were evaluated. Dietary choline supplementation yielded better feed conversion rate; fish fed diet containing 32.0% DP had lower HSI and VF and diet containing eliciteol 3500 kcal kg-1 best health condition after stress, while fish fed diets with 32.0% DP plus 3500 kcal DE kg-1 and supplemented with choline had better productive performance and were healthier
5

Proteína e energia digestíveis e colina para Tilápia-do-Nilo : desempenho e respostas fisiológicas em condições de estresse /

Fernandes Junior, Ademir Calvo, 1984- January 2012 (has links)
Orientador: Margarida Maria Barros / Coorientador: Luiz Edivaldo Pezzato / Banca: José Eurico Possebon Cyrino / Banca: Wilson Massamitu Furuya / Banca : Ana Lucia Salaro / Banca: Leandro Portz / Resumo: Pesquisas para determinar a exigência em proteína e energia digestíveis e colina simultaneamente são excassas. Este estudo avaliou o efeito da proteína e energia digestíveis e colina no desempenho produtivo e nas respostas fisiológicas da tilápia-do-Nilo. Juvenis (87,0 ± 7,0 g), identificados individualmente com micro-chipe foram distribuídos em 40 aquários de 250L (8 peixes/aquário) utilizando um delineamento experimental inteiramente casualizado com 20 tratamentos em esquema fatorial 5x2x2 e 16 repetições: 24,0; 26,0; 28,0; 30,0 e 32,0% proteína digestível, 3200 e 3500 kcal kg-1 energia digestível e 0,0 e 1000,0 mg colina kg-1. Foram determinados parâmetros de desempenho produtivo, índice hepatossomático, gordura visceral, além das respostas fisiológicas antes e após estímulo a quente. A dieta suplementada com colina melhorou a conversão alimentar aparente; os peixes alimentados com dieta com 32,0% PD tiveram menores IHS e GV e a dieta com 3500 kcal ED kg-1 determinou melhores condições de saúde após estresse, enquanto que os peixes alimentados com dieta com 32,0% PD com 3500 kcal ED kg-1, e suplementada com colina determinou melhor desempenho produtivo e higidez dos peixes / Abstract: Researche effects aimed at determing digestible energy, protein and choline requirement simultaneous by are scarce. This study evaluated effects of digestible protein, digestible energy and choline in the physiological response and growth performance of Nile tilapia. Juveniles (87.0 ± 7.0 g), individualy taged Nile tilapia (Animaltag®) were randomly distributed into 40, 250-L 8 fish per tank seting up a totally randomized trial, 5x2x2 factorial arrangement, with twenty treatments (n=2): 24.0; 26.0; 28.0; 30.0 and 32.0% digestible protein, 3200 and 3500 kcal kg-1 digestible energy and 0.0 and 1000 mg choline kg-1 diet. Growth performance, hepatosomatic index, visceral fat and physiological response before and after heat stress were evaluated. Dietary choline supplementation yielded better feed conversion rate; fish fed diet containing 32.0% DP had lower HSI and VF and diet containing eliciteol 3500 kcal kg-1 best health condition after stress, while fish fed diets with 32.0% DP plus 3500 kcal DE kg-1 and supplemented with choline had better productive performance and were healthier / Doutor
6

Isótopos estáveis de C e N como indicadores da dieta da Tilápia do Nilo (Oreochromis niloticus) cultivada em tanques-rede em reservatório do semiárido brasileiro / Stable isotopes of C and N as dietary indicators of Nile tilapia (Oreochromis niloticus) cultivated in cages in the Brazilian semiarid region of the reservoir

Moraes, Cyntia Rafaela Ferreira de 25 February 2016 (has links)
Made available in DSpace on 2016-08-15T20:31:34Z (GMT). No. of bitstreams: 1 CyntiaRFM_DISSERT.pdf: 1600999 bytes, checksum: 4275db45083eb06dd6e32765b5903df7 (MD5) Previous issue date: 2016-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study investigated the relative contribution of natural food and commercial diets assimilated into the Nile tilapia nutrition (nilloticus niloticus) cultured in cages in the reservoir of Santa Cruz-Apodi / RN. All samples of diets and individuals were held between August and November 2013 in the reservoir cages. Individuals throughout the cultivation, as well as take in the natural food, were feed a control 40 and 32% crude protein for three stages of cultivation. For sampling isotopes dorsal muscle samples were taken from 15 individuals captured, collected food samples 15, periphyton and seston (local water filtration). All samples were dried in an oven at a temperature between 55-60 °C for a period ranging from 36-72 hours, and ground in a mortar and pestle manual to a fine powder. were performed sweeps on material samples filters. The powder samples were stored in tin capsules for conducting the analysis of stable isotopes 15N and 13C for tissue samples and diets which were performed at UC Davis Stable Isotope Laboratory Facility, University of California - USA. The field was monitored the limnological variables with the use of a multisensor. In laboratory Limnologia and Water Quality - LIMNOAQUA, analyzes were performed of growing water, in order to characterize the conditions of abiotic cages. The results of the ratios of C and N isotopes for diets and diets of fish and the contribution rates were analyzed using the R software, version 3.2.2. For data of stable isotopes of carbon and nitrogen, for samples with normal distribution and homogeneous variance was applied one-way ANOVA and Tukey test a posteriori. Where the ANOVA assumptions were not satisfied we used the nonparametric Kruskal-Wallis test and paired Wilcoxon. The values of the isotopic ratios were analyzed individually by period. Regarding the values of the contribution rates of the diets were analyzed together for each period. It was used Mixsiar Mixture Model to determine the relative contribution of diets. Limnological variables did not vary during the study period, only variations were observed for total phosphorus concentrations in the final cultivation stage and chlorophyll-a in the entire study period. Samples of feed showed significant differences in isotopic composition of 13C, and the values of 15N in tissue samples from fish between periods I and II, occurring distinct discriminating rates in diet-tissue interface for both isotopic elements of C and N in all diets. The waste feed supplied contributed to the high availability of natural foods, especially for diet based on seston.The periphyton diet (26.6%) had reduced contribution compared the diets of seston (39.2%) and fish feed (34.3%) for fish reared in Santa Cruz. In this context, it can be concluded that natural diet - seston and periphyton - (65.8%) contributed to the growth of Nile tilapia cultured in cages, changing the paradigm that only provided food is assimilated by the fish, contributing so almost exclusively on the growth of this species / A presente pesquisa investigou a contribuição relativa dos alimentos naturais e dietas comerciais assimilados na nutrição de tilápia do Nilo (Oreochromis niloticus) cultivada em tanques-rede no Reservatório de Santa Cruz-Apodi/RN. Todas as coletas das dietas e indivíduos foram realizadas entre agosto e novembro de 2013, nos tanques-rede do reservatório. Os indivíduos durante todo o cultivo, além de assimilar o alimento natural, foram alimentados com ração comercial de 40 e 32% de proteína bruta durante três fases de cultivo. Para as amostragens de isótopos foram retiradas amostras da musculatura dorsal de 15 indivíduos capturados, e recolhidas 15 amostras de ração, perifíton e seston (filtragem da água local). Todas as amostras foram secas em estufa com temperatura entre 55-60 °C por um período variando entre 36-72 horas, e moídas em almofariz manual e pistilo até formar um pó fino. Foram realizadas raspagens do material nas amostras de filtros. As amostras em pó foram armazenadas em cápsulas de estanho para realização da análise de isótopos estáveis de 13C e 15N para as amostras de tecidos e dietas, que foram realizadas pelo laboratório UC Davis Stable Isotope Facility, Universidade da Califórnia EUA. Em campo foi realizado o monitoramento das variáveis limnológicas com o uso de um multisensor. No laboratório de Limnologia e Qualidade de Água LIMNOAQUA, foram realizadas análises da água de cultivo, com o intuito de caracterizar as condições abióticas dos tanques-rede. Os resultados das razões de isótopos de C e N para as dietas e peixes e das taxas de contribuições das dietas foram analisados utilizando o software R, versão 3.2.2. Para os dados de isótopos estáveis de C e N, para as amostras que apresentaram distribuição normal e variância homogênea foi aplicada uma ANOVA one-way e teste a posteriori de Tukey. Nos casos em que os pressupostos da ANOVA não foram satisfeitos foi aplicado o teste não-paramétrico de Kruskal-Wallis e teste pareado de wilcoxon. Os valores das razões isotópicas foram analisados individualmente por período. Em relação aos valores das taxas de contribuição das dietas, foram analisadas em conjunto para cada período. Foi utilizado o Modelo de Mistura Mixsiar para determinar a contribuição relativa das dietas. As variáveis limnológicas não apresentaram variações no período estudado, apenas ocorreram variações para as concentrações fósforo total na fase final de cultivo e clorofila-a em todo o período estudado. As amostras de ração apresentaram diferenças significativas em sua composição isotópica de 13C, e para os valores de 15N nas amostras teciduais de peixes entre os períodos I e II, ocorrendo taxas discriminantes distintas na relação tecido-dieta para ambos os elementos isotópicos de C e N em todas as dietas. Os resíduos de ração ofertada contribuíram para a elevada disponibilidade das dietas naturais, especialmente para a dieta com base no seston. A dieta de perifíton (26,6 %) apresentou contribuições reduzidas em relação as dietas de seston (39,2 %), e ração (34,3 %) para os peixes cultivados em Santa Cruz. Neste contexto, pode-se concluir que a dieta natural seston e perifíton - (65,8%) contribuiu no crescimento da tilápia do Nilo cultivada em tanques-rede, alterando o paradigma de que apenas a ração fornecida é assimilada pelos peixes, contribuindo de forma quase que exclusiva no crescimento desta espécie

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