Restrições econômicas e ambientais trazem a necessidade de substituir a farinha de peixe em dietas de organismos aquáticos por matérias-primas menos dispendiosas de origem vegetal. Entretanto, tais fontes proteicas vegetais possuem fatores antinutricionais que podem ter efeitos negativos sobre o sistema digestório dos peixes, alterando a saúde e, em consequência, a produção. O objetivo deste trabalho foi avaliar a digestibilidade e alterações na histologia do epitélio intestinal de juvenis do Characiforme carnívoro dourado, Salminus brasiliensis, alimentados com dietas contendo farelo de soja (FSO), farelo de algodão (FAl) e farelo de amendoim (FAM) como principais fontes proteicas. Foram conduzidos dois experimentos: digestibilidade (Ensaio I) e histológico (Ensaio II). O Ensaio I foi conduzido em protocolo padrão utilizando dietas práticas adicionadas do marcador inerte óxido de crômio III (CR2O3) e sistema Guelph modificado para coleta de fezes e consequente cálculo dos coeficientes de digestibilidade. No Ensaio II as mesmas fonte proteicas - FSO, FAL e FAM - foram utilizadas em substituição à proteína da farinha de peixe em uma dieta controle com cinco níveis de inclusão: 0 (controle), 25,0 %; 50%; 75,0% e 100%, em um delineamento inteiramente aleatorizado (n=3). O experimento teve a duração de 40 dias, e as coleta de amostras de tecido foram feitas aos 20 e 40 dias. As amostras do intestino posterior foram analisadas quanto às características histológicas e morfológicas, além de quantificação de células caliciformes e análise histomorfométrica do tecido intestinal. Não foram registradas diferenças para os coeficientes de digestibilidade da proteína e energia no ensaio de digestibilidade. O ensaio de desempenho mostrou que a inclusão de FAM e FAL nas dietas melhora o consumo de alimento comparativamente ao FSO Em relação as variáveis histológicas, os níveis que condicionaram alterações significativas nos parâmetros morfométricos foram FSO50 e FOS75. O FSO50 promoveu uma redução das dobras intestinais aos 20 dias, porém aos 40 dias houve aumento na altura das dobras, no espessamento da lâmina-própria e aumento na densidade das células caliciformes. Considerando a microscopia de varredura, sinais acentuados de enterite foram registrados. A alteração na morfologia e histologia do epitélio intestinal foi reflexo da interação de efeitos dos fatores antinutricionais presentes em cada fonte proteica vegetal. Consequentemente, registrou-se menor ganho de peso, crescimento e diminuição da homeostase intestinal, embora os melhores consumos e CAA fossem registrados para os peixes alimentados com FAL e FP. Conclui-se que o FSO causou enterite nos juvenis de dourado e FAL e FAM podem ser utilizados na alimentação de dourado. / Economic and environment constraints have brought the need to replace fishmeal (FM) in diets of aquatic organisms by less expensive feedstuff, especially dietary protein sources. However, such protein sources generally of plant origin, e.g. soybean meal, have antinutritional factors that can negatively affect digestive system of the fish, impairing health and consequently, production. To identify possible effects of plant protein sources in the diets for carnivore fish, this study evaluated effects of various dietary plant protein sources on digestibility, performance, histology of the intestinal epithelium of the carnivore, Neotropical Characin dourado, Salminus brasiliensis, fed plant protein-based diets. A digestibility trial was carried out in standard protocol using diets with inert marker chromium oxide III (Cr2O3) and modified system Guelph for feces. A performance test evaluated the use of three plant protein sources, soybean meal (SBM), cottonseed meal (CTM) and peanut meal (PTM) as surrogate protein source to fishmeal in a practical diet in five levels inclusion: 0 (control); 25.0%; 50.0%; 75.0% and 100%, in a randomized block design (n=3). Samples of tissue of intestinal tract of fish were collected in the distal segment at 20 and 40 days of the feeding period, and analyzed for histological and morphological characteristics. No differences were recorded for apparent digestibility coefficients (ADC) of feedstuff and energy and protein of feedstuffs. Dietary CM and PM elicited better feed consumption comparatively to the other feedstuff, Fish fed diet diet SBM50 presented reduction of intestinal folds at 20 days, but at 40 days had increased folds height, lamina propria thickening, and increased goblet cell density. Considering a scanning microscopy, evident signs of enteritis were registered. The alteration in the morphology and histology of the intestinal epithelium reflected the interaction of effects of the antinutritional factors present in each vegetable protein source, resulting in lower weight gain, growth and decreased intestinal homeostasis, even though best feed consumption and ADC were registered for fish fed CTM and FM.Concluded that SBM caused enteritis and CTM and PM can be used in feeding dourado.

Master of Science

La présente étude s’inscrit dans une approche perspective d’augmentation de la production halieutique nationale par l’amélioration des techniques piscicoles déjà existantes, notamment les trous traditionnels à poissons (whedos), dans le delta du fleuve Ouémé (sud Bénin). Les premières approches de nos investigations montrent que, sur le plan socio-économique, l’augmentation de la productivité des whedos s’avère nécessaire pour l’amélioration des conditions de vie des pêcheurs dans la Vallée de l’Ouémé. En effet, avec le mode actuel de gestion des whedos, le revenu net par hectare et par an peut varier entre 182.000 et 572.000 Fcfa. Il représente au niveau actuel environ 27 % des revenus totaux de la pêche par ménage. Cependant, avec la mise en charge et l’alimentation artificielles d’espèces piscicoles adaptées, telles que les poissons-chats Clarias gariepinus et Heterobranchus longifilis, des rendements annuels de 3 à 36 t ha-1 peuvent être obtenus en fonction des densités d’élevage (respectivement de 4 à 24 poissons m-3). Les revenus nets provenant d’une telle gestion sont assez importants et peuvent varier en fonction de la densité de mise en charge, entre 1.664.000 et 31.675.000 Fcfa (respectivement de 4 à 24 poissons m-3). Ainsi, bien que la densité de 10,5 poissons m-3 soit apparue comme étant idéale pour l’optimisation des performances zootechniques, la recherche du profit maximal nous amène à suggérer pour la promotion de l’élevage de C. gariepinus dans les whedos, l’utilisation des densités plus élevées (environ 24 poissons m-3) afin de maximiser leurs capacités de production. Par ailleurs, la nécessité de production massive d’alevins de ces poissons-chats s’est avérée indispensable pour la promotion effective de leur élevage en whedos. A cet effet, nous avons évalué quelques aspects de l’élevage larvaire de ces espèces (âge de sevrage et densité de stockage), de même que les effets zootechniques et nutritionnels de différents régimes à base des tourteaux de soja et de coton aussi bien chez les larves que les juvéniles. Il ressort de ces études que le sevrage des larves de H. longifilis, maintenues à des densités de 10 à 25 individus L-1, est nécessaire entre les jours 5 et 8 post-éclosion afin d’optimiser aussi bien les performances zootechniques qu’économiques de l’élevage. D’autre part, le tourteau de soja s’est avéré plus efficace que celui de coton aussi bien chez les larves que les juvéniles de ces poissons-chats. Cependant, la présence des facteurs antinutritionnels, notamment l’acide phytique, limite les niveaux d’utilisation de ces tourteaux dans les régimes, étant donné que chez les juvéniles des réductions significatives des teneurs corporelles en minéraux, notamment en P, Zn et Mn ont été observées avec les régimes contenant jusqu’à 60 % de ces tourteaux. The present study aims to appraise the perspectives to increase the national fish production by improving the existing fish production systems, as the traditional fish pond (whedos), in the Ouémé River delta (southern Benin). The first approaches of our investigations show that, on the socio-economic level, the increase in the productivity of the whedos seems necessary to improve the livelihood conditions of the fishermen in the Ouémé Valley. Indeed, with the current mode of management of these whedos, we have observed that the net income per hectare can vary between 182,000 and 572,000 Fcfa. It represents, at the current level, approximately 27 % of the total incomes of fishing per household. However, by artificial stocking with adapted fishes, such as the catfishes Clarias gariepinus and Heterobranchus longifilis, and feeding, the annual outputs from 3 to 36 t ha-1 can be reached according to the stocking densities (from 4 to 24 fish m-3, respectively). The nets incomes generated from such management are rather important and can vary according to the stocking densities from 1,664,000 to 31,675,000 Fcfa (from 4 to 24 fish m-3, respectively). Although the density of 10.5 fish m-3 seemed ideal for the optimization of zootechnical parameters, the search of maximum profit leads us to suggest the higher densities (approximately 24 fish m3) for rearing African catfish in the whedos. Moreover, to improve the knowledge of these catfishes fingerlings production, we evaluated some aspects of the larval rearing (weaning time and stocking density), just as the nutritional effects of various diets, based on soybean or cottonseed meals, in the larvae as well as in the juveniles. It arises from these studies that, the weaning of H. longifilis larvae maintained at the densities from 10 to 25 L-1, is necessary between days 5 and 8 posthatch in order to optimize the zootechnical and economical performances of the rearing. Furthermore, we have observed that soybean meal was more effective than cottonseed meal in the larvae as well as in the juveniles. However, the presence of antinutrients factors, particularly the phytic acid, limit the levels of inclusion of these oilseed meals in the diets, since in juveniles, significant reductions of the body minerals contents, particularly P, Zn and Mn, were observed with the diets containing up to 60 % of these plants ingredients.

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.

Literature shows that production of cottonseed adhesives is feasible to develop an environmentally friendly and competitive bio-based wood adhesive. Defatted cottonseed and water-washed cottonseed meals were prepared from glandless cottonseed and were used in adhesive formulations to produce three-ply yellow poplar (Liriodendron tulipifera) plywood panels as the first objective. These two cottonseed meals were compared with the properties of plywood panels made with an adhesive formulated from a commercial soybean meal, as a control. Adhesive resins were prepared from each protein meal with sodium metabisulfite (Na2S2O5) and one of two polyamido-amine-epichlorohydrin (PAE) wet strength agents, and the plywood panels were produced by hot pressing for 7, 8.5 and 10 minutes at 135°C with a constant pressure of 1.241 MPa. Panels prepared from three protein meals had comparable shear strengths. The combinations of the two cottonseed preparations and the two wet strength agents produced panels with acceptable wet resistant properties, whereas the soybean meal only produced acceptable panels with one of the wet strength agents. Because the panels prepared from the two cottonseed meals had comparable properties, there appears to be no benefit to including a water-washing step to increase the meal’s protein level. The second objective of this research was to reduce the hot press time and develop cottonseed meals into adhesives to become comparable to commercial soybean-based adhesives. New cottonseed, water-washed cottonseed, and commercial in-house soybean meals were separately prepared with deionized water, sodium metabisulfite, and PAE to produce three-ply yellow poplar plywood panels. The panels were hot pressed for 4, 5, and 6 minutes at 135°C with a constant pressure of 1.241 MPa. Panels prepared from the three meals and commercial soybean plywood panels had comparable mechanical shear strengths and water resistance properties. Results indicated that press time, meal types, and interactions were statistically significant. Shear strength results indicate that cottonseed could be used alternatively to soybean. The new cottonseed panels were more resistant to delamination than soybean. The cottonseed meals showed great promise for applicability as a formaldehyde-free, bio-based, and environmentally friendly hardwood plywood wood-based adhesives product for use in interior type applications.