Antinutritional factors present in plant-derived alternate fish feed ingredients and their effects in fish

This review summarizes information regarding digestion and absorption of carbohydrates in cultivated fish Relevant results of studies of digestive enzymes, eg amylase, chitinase, cellulase and brush border disaccharidases are presented Fish amylases appear to be molecularly closely related and to have characteristics comparable to mammalian amylases Whether chitinases and cellulases are endogenous enzymes of some fish species is still a matter of speculation, although recent molecular evidence, at least for chitinase seems to settle the issue in favour of endogenous sources Feed and intestinal microbes may be the source of polysaccharidases in fish feeding on nutrients-containing non-starch polysaccharides Knowledge regarding monosaccharide transport in fish intestine as interpreted from studies of brush border membrane vesicles, everted sleeves of fish intestinal sections and molecular biology is discussed Glucose transporters of the intestinal brush border show characteristics similar to those found in mammals A tabulatory presentation of experimental details and results reported in the literature regarding starch digestibility is included as a basis for discussion Although numerous investigations on digestion of starch and other carbohydrates in fish have been published, the existing information is highly fragmentary As yet, it is impossible to derive a cohesive picture on the integrated process of carbohydrate hydrolysis and absorption and interaction with diet composition for any of the fish species under cultivation The physiological mechanisms behind the species differences are not known

Carbohydrates in fish nutrition: digestion and absorption in postlarval stages

Alternative dietary protein sources for farmed tilapia, Oreochromis spp.

Digestion of food depends on three main factors: (i) the ingested food and the extent to which the food is susceptible to the effects of digestive enzymes, (ii) the activity of the digestive enzymes and (iii) the length of time the food is exposed to the action of the digestive enzymes. Each of these factors is affected by a multitude of secondary factors. The present review highlights the experimental results on the secondary factor, enzymatic activity and possible contribution of the fish gut microbiota in nutrition. It has been suggested that fish gut microbiota might have positive effects to the digestive processes of fish, and these studies have isolated and identified the enzyme-producing microbiota. In addition to Bacillus genera, Enterobacteriaceae and Acinetobacter, Aeromonas, Flavobacterium, Photobacterium, Pseudomonas, Vibrio, Microbacterium, Micrococcus, Staphylococcus, unidentified anaerobes and yeast are also suggested to be possible contributors. However, in contrast to endothermic animals, it is difficult to conclude the exact contribution of the gastrointestinal microbiota because of the complexity and variable ecology of the digestive tract of different fish species, the presence of stomach and pyloric caeca and the relative intestinal length. The present review will critically evaluate the results to establish whether or not intestinal microbiota do contribute to fish nutrition.

Enzyme‐producing bacteria isolated from fish gut: a review

Utilization of waste sludge as a renewable resource for energy recovery is the appropriate solution of how to manage the continuously increasing waste sludge generation effectively in order to meet stringent environmental quality standards, and at the same time, how to sustain the supply of reliable and affordable energy for our future generations and ourselves. The valuable characteristics of sludge, including high energy and nutrient content, with the stringent criteria of sludge disposal, driving the environmental engineers and scientist to change their standpoint to considering sludge as a viable resource of energy instead of a waste. It may be an important move towards the development of a sustainable energy solution to fulfill present and future energy requirements and thus reduce the dependency on non-renewable resource. Thus, this review discusses about the type of resources that can be recovered from waste sludge and, conventional and emerging methods used to convert the sludge into valuable resources. Moreover, the major factors involved in the process, stage of application, advantages and possible drawbacks of the methods are also discussed.

Sludge: A waste or renewable source for energy and resources recovery?

Water stability, nutrient leaching and nutritional properties of moist fermented fish silage diets

Growth and protein utilization by juvenile catfish (Clarias gariepinus) fed dry diets containing co-dried lactic-acid-fermented fish-silage and protein feedstuffs

Nutritive value of diet containing dried lactic acid fermented fish silage and soybean meal for juvenile Oreochromis niloticus and Clarias gariepinus

Preparation, nutrient composition and digestibility of fermented shrimp head silage

Haematological profile of Heterobranchus bidorsalis (Geoffroy St. Hilaire 1809) was determined. Haematocrit values, haemoglobin concentrations, erythrocyte and leucocyte counts, mean cell haemoglobin concentration, sodium and potassium ions concentrations were 24.75±1.23%, 5.43±0.25 g/100 ml, 1.99±0.52 106/mm3 and 7.25±0.60 104/mm3, 22.11±0.77%, 802.52±36.97 and 83.54±5.05 mg/1, respectively. H. bidorsalis fingerlings were subjected to a range of salinities, 0, 3, 6, 9, 12 and 15 ppt. The optimum salinity range for survival and good growth performance was determined as 0–3 ppt. Survival was >85% from 0–9 ppt with no significant differences (P>0.05), but decreased progressively as salinity increased. Qualitative and quantitative assays of digestive enzymes in the different regions of H. bidorsalis guts revealed an array of carbohydrases, proteases and lipases. Enzyme activity was restricted to the stomach, duodenum and ileum with fewer enzymes recorded in the stomach. The pattern of distribution and relati...

https://www.tandfonline.com/doi/pdf/10.1080/03946975.1993.10539209

Oyedapo A. Fagbenro

Papers

Water stability, nutrient leaching and nutritional properties of moist fermented fish silage diets

Growth and protein utilization by juvenile catfish (Clarias gariepinus) fed dry diets containing co-dried lactic-acid-fermented fish-silage and protein feedstuffs

Nutritive value of diet containing dried lactic acid fermented fish silage and soybean meal for juvenile Oreochromis niloticus and Clarias gariepinus

Preparation, nutrient composition and digestibility of fermented shrimp head silage

Studies on the biology and aquaculture potential of feral catfish Heterobranchus bidorsalis (Geoffroy St. Hilaire 1809) (Clariidae)