Doctor of Philosophy / Department of Grain Science and Industry / Keith C. Behnke / A series of experiments was conducted to compare methods used to evaluate the durability of animal feed pellets, as well as to investigate the potential for modeling the effects of formulation and processing factors on both pellet durability index (PDI) and pelleting energy consumption, measured in kilowatt hours per ton (kWh/ton). Seven different factors, including ground corn particle size, added fat level, inclusion of distillers dried grains with solubles (DDGS), feed rate, steam conditioning temperature, conditioner retention time, and pellet die thickness (L:D ratio) were examined. Each factor was evaluated at two levels, and treatments were developed in order that all factor to factor comparisons could be made. Pellet samples were analyzed according to the standard method as described in ASAE S269.4, a modification of this method, and by using the NHP100 pellet tester set to each of its four testing intervals (30, 60, 90, and 120 seconds). The standard method was found to provide the most consistent and repeatable determinations of pellet durability, and was found to correlate well with the modified method, as well as with the NHP100 results at 30 and 60 seconds. Physical attributes of feed pellets, such as pellet hardness, bulk density, and moisture content were found to have significant, but weak correlations with pellet quality. Pellet quality was found to be significantly influenced by all factors other than ground corn particle size and feed rate. Higher fat level, lower conditioning temperature, and the thinner pellet die most significantly lowered pellet quality, with increasing effect respectively. A regression model was developed that was able to predict pellet durability within an average of 1.1 PDI. Pelleting energy consumption was found to be significantly influenced by all seven factors, with the higher fat level, thinner pellet die, and higher conditioning temperature most improving efficiency, with increasing effect respectively. A regression model was developed that was able to predict energy consumption within an average of 0.3 kWh/ton. The successful creation of regression equations demonstrates that there is potential for modeling and optimizing pellet quality and energy consumption within a pelleting operation.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 4 uppsatser.

Made available in DSpace on 2015-05-07T14:49:14Z (GMT). No. of bitstreams: 1 parte1.pdf: 2218447 bytes, checksum: 089f22b3a430d6cd78b952e8351c0b9f (MD5) Previous issue date: 2011-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Fishing is a very important activity for the provision of protein, but as a result of the heavy pressure from extractive fishing and above the limits of carrying capacity of populations of commercial species, many stocks are at or above the limit of exploration, which has resulted in decreased populations of many animals, including driving some to extinction. As a result, aquaculture has increased worldwide, complementing the fisheries to obtain quality protein. By the increasing investment in this activity, it became one of the fastest growing economic activities worldwide, nowadays. Brazil is no different, and aquaculture has been growing over the years, and most fish cultures are being developed in freshwater ecosystems, and the crustacean culture in estuarine ecosystems. However, if this activity is not performed properly, can be quite impactant to natural ecosystems, as a result of the addition of nutrients, leading to eutrophication. In addition, breeding has been mostly with exotic species, which when they arrive in the natural habitat suppress native species, leading to the decreasing in local biodiversity. Antibiotics and other crops and products placed in the diets also end up interfering with the water quality of natural systems. Therefore, it is important that aquaculture should be promoted, as a promising economic activity, with capacity for growth in Brazil, and if it is practiced at the household level could contribute to the economic growth of traditional communities or poor ones, thus contributing to the local sustainable development. Thus, the aim of this thesis was to implement a training course for fishermen of Lucena and Fagundes beaches and farmers living in three settlements in Lucena municipality, so that they could further develop this activity in a sustainable manner. For that, ecological methods, such as horticultural waste recovery and preparation of alternative feeds for the reduction of production costs, were applied. The whole process was conducted in the form of action research among researchers and participants in the extension project PROEXT 2008, funded by the MEC / SESU. The course showed how to cultivate two fish species, carp and Nile tilapia, in a polyculture system. The results of this activity were very promising, the participants enjoyed the experience and showed interest in continuing by their own later. All the course members made all the activities, from the excavation of ponds until removal of the fishes. This study had shown that they can work successfully in teams, which they did not believe at first. The performance of the fish along the cultivation revealed that the alternative diet promoted a better growth performance of carp development, but a lower growth in tilapia. The nutrient analysis of the two diets, commercial and alternative, showed that the protein content was higher in commercial feed, which may have caused the difference in tilapia growth. Moreover, the economic analysis of cultivation with the two diets showed that the profit was very similar in the two analyzed ponds, due the lower feed cost of the alternative ration. The course has proved a success, and the participants learned to practice the procedures for aquaculture, being able to play all the activities learned and can thus diversify production on the properties and the fishermen, if they get a local for cultivation, depend less on fish stocks, thus ensuring greater security for their maintenance and cause a less pressure over species in the environment, allowing them to recover. / A pesca é uma atividade muito importante para a obtenção de alimentos protéicos, mas em conseqüência da grande pressão do extrativismo e da captura acima dos limites da capacidade de suporte das populações de espécies comerciais, muitos estoques estão no limite de exploração ou acima deste, o que tem resultado na diminuição de muitas populações de animais, inclusive levando algumas ao risco de extinção. Em virtude disso, a aqüicultura tem aumentado em todo o mundo, complementando a pesca para a obtenção de proteína de qualidade. Pelo maior investimento nesta atividade, esta tornou-se uma das atividades econômicas que mais cresce no mundo atualmente. No Brasil não é diferente, e a aqüicultura vem crescendo ao longo dos anos, sendo a piscicultura mais praticada em ecossistemas fluviais, e a carcinocultura em ecossistemas estuarinos. No entanto, se esta atividade não for realizada de forma adequada, poderá ser bastante impactante aos ecossistemas naturais, em conseqüência da adição de nutrientes, levando-os à eutrofização. Assim sendo, é importante que a aqüicultura seja incentivada, por ser uma atividade econômica promissora, com capacidade de crescimento no Brasil, e que se praticada a nível familiar poderá contribuir com o crescimento econômico de comunidades tradicionais ou carentes, contribuindo assim, com o desenvolvimento sustentável local. Desta forma, o objetivo desta dissertação foi o de participar de um curso de capacitação para pescadores das praias de Lucena e Fagundes e agricultores residentes em 2 assentamentos no município de Lucena, de forma a que eles pudessem futuramente desenvolver esta atividade de forma sustentável. Para isso, metodologias ecológicas, como o aproveitamento de resíduos hortifrutigranjeiros e a preparação de rações alternativas, para o barateamento da produção, foram aplicadas. Todo o processo foi realizado na forma de pesquisa-ação entre os pesquisadores e os participantes do projeto de extensão PROEXT 2008, financiado pelo MEC/SESU. O curso mostrou como cultivar duas espécies de peixe em policultivo, a carpa e a tilápia nilótica. Os resultados da atividade foram bastante promissores, os participantes gostaram da experiência e mostraram interesse em continuar. Todos os integrantes do curso realizaram todas as atividades, desde a escavação dos viveiros até a despesca. Ao mesmo tempo, com este trabalho foi possível verificar que eles podem trabalhar em equipe com sucesso, o que eles não acreditaram muito no início. O desempenho dos peixes ao longo do cultivo revelou que a ração alternativa promoveu um melhor desempenho no crescimento da carpa, mas um crescimento menor na tilápia. A análise bromatológica das duas rações, a comercial e a alternativa, revelou que o teor de proteínas foi mais elevado na ração comercial, o que pode ter causado essa diferença no crescimento das tilápias. Por outro lado, a análise econômica do cultivo com as duas rações mostrou que o lucro foi muito semelhante nos dois viveiros analisados, em virtude do menor custo da ração alternativa. A capacitação dos atores sociais revelou-se um sucesso, os participantes assimilaram a técnica da piscicultura, sendo capazes de reproduzir todas as atividades, podendo desta forma diversificar a produção nas suas propriedades, assim como, os pescadores, que se conseguirem local para o cultivo, dependerão menos dos estoques pesqueiros, podendo garantir com mais segurança o seu sustento e diminuindo ao mesmo tempo a superexploração das espécies de peixes no ambiente, permitindo a sua recuperação.

One of the major problems facing aquaculture in Ghana is the non-availability of quality and affordable fish feeds. The present study investigated the nutritional suitability and cost-effectiveness of some Ghanaian oilseed by-products, soybean meal (Glycine spp), cottonseed meal (Gossypium spp), groundnut cake (Arachis hypogaea L.) and groundnut husk, as alternative protein sources to fishmeal (FM) in the diet of Nile tilapia (Oreochromis niloticus L.). The oilseed meals were used individually, as mixtures, as mixtures enriched with methionine and mixtures detoxified by heat processing (autoclaving) and/or addition of supplements (viz. phytase and ferrous sulphate) intended to reduce levels of the most important antinutritional factors (ANFs). Diets, containing the oilseed meals at inclusion levels from 25% to 75% dietary protein, were formulated to be isonitrogenous (320 g.kg-1), isolipidic (100 g.kg-1) and isoenergetic (18 KJ.g-1) and fed to juvenile Nile tilapia at 4-10% of their body weight for a period of eight weeks. Proximate analysis showed that soybean meal (SBM), cottonseed meal (CSM), groundnut cake (GNC) and groundnut husk (GNH) had 500.3, 441.4, 430.5 and 205.6 g.kg-1 crude protein, 38.2, 89.5, 12.8 and 89.2 g.kg-1 crude fibre and 20.19, 19.61, 23.17 and 22.18 kJ.g-1 gross energy respectively. Generally the oilseed meals had good essential amino acid (EAA) profiles with the exception of GNH. The EAA profile of SBM compared very well with FM but methionine and threonine were low (0.73 and 1.50 % of protein respectively) and the same was true for CSM and GNC with even lower levels. Analyzed ANFs in SBM, CSM, GNC and GNH were 17.54, 31.64, 14.86 and 3.99 g.kg-1 phytic acid, 14.09, 1.24 and 2.34 g.kg-1 trypsin inhibitors and 5.80, 6.50, 8.01 and 10.08 g.kg-1 saponin respectively and in CSM 5.6 g.kg-1 gossypol. Nutrient digestibility of these oilseed proteins suggested that Nile tilapia may be able to utilize SBM, CSM and GNC efficiently as dietary protein sources due to high apparent protein digestibility of 94.50%, 84.93% and 90.01% respectively. However, GNH may not be suitable because of very low apparent protein digestibility (27.67%). These protein sources when used individually were shown to cause depressed growth and feed efficiency when substituting more than 50% of the FM protein in diets. This may be attributed to high levels of ANFs, high fibre content and poor EAA profile. However, the use of mixtures of these meals was found to be marginally more effective than that of single sources. This may have been as a result of lower levels of ANFs and improvement in essential amino acid profile due to mixing. Supplementing the mixtures with methionine led to improvement in feed utilization but without significantly improving the nutritive value compared with FM. Heat processing was effective in reducing heat labile trypsin inhibitors in SBM, CSM and GNC by almost 80%, but not phytic acid and saponins, which remained virtually unaffected. Use of meals detoxified by heat processing with/without supplements at 50% inclusion improved growth and feed utilization compared to the unprocessed meals and performance was generally not significantly different from FM. Cost effectiveness analysis revealed that diets containing single feedstuffs or mixtures, particularly those containing equal proportions of oilseed meals and higher proportion of CSM replacing between 50% - 75% FM protein, were more profitable than FM diet. Similarly, the use of heat processed meals at 50% replacement of FM protein yielded greater profit than all other diets including the FM diet. However, essential amino acid supplementation of the meals was less profitable compared to the control. Generally, fish fed diets with oilseed meals would take longer to attain harvest size compared with FM and this could lead to an increase in production costs or a decrease in the number of production cycles which could be achieved within a year. It can be concluded that there is nutritional and economic justification for using SBM, CSM and GNC as partial replacement for FM in diets of Nile tilapia. Based on growth performance, nutrient utilization and economic benefits the diet with heat processed oilseed meal mixtures (containing equal proportions of 16.67% each) at 50% inclusion has the best prospects for replacing FM protein in diets of O. niloticus.

Single cell proteins such as that of edible filamentous fungal biomass are considered as a promising sustainable source of animal feed supplementation. Filamentous fungi can be cultivated on different organic substrates including volatile fatty acids (VFAs) such as acetic, propionic, and butyric acids. These VFAs can be generated through the famous waste valorisation approach of anaerobic digestion (AD) as intermediate metabolites. This project investigates a sustainable approach for the production of animal feed supplementation through cultivation of fungal biomass on waste derived VFAs along with the in vitro analysis of fungal biomass digestibility as ruminant feed. In this regard, optimum conditions for the production of Aspergillus oryzae biomass on different VFAs effluents derived from anaerobic digestion process of food waste plus chicken manure (FWCKM) and potato protein liquor (PPL) at different pH, nitrogen sources, and feed mixture was studied. Accordingly, analyses showed that PPL has the highest biomass yield with 0.4 (g biomass/g consumed VFAs) based on the volatile solids (VS) by adjusting pH to 6.2. Furthermore, the digestibility of the produced fungal biomass is analysed by using three different in vitro digestion methods including Tilley and Terry (TT) method, Gas Production Method (GPM), and Nylon Bag Method (NBM) and the results are compared with the conventional feed (silage and rapeseed meal). Results obtained from different digestibility methods illustrate that different A. oryzae fungal biomass had approximately 10-15 % higher dry matter digestibility fraction compared to silage and rapeseed meal (reference feeds). Hence, these results revealed that A. oryzae fungal biomass can grow on VFAs effluents and produce protein-rich fungal biomass while this biomass has better digestibility compared to conventional feeds and confirmed the initial hypothesis of the study.