GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Document type
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    Type of dietary fibre (soluble versus insoluble) influences digestion, faeces characteristics and faecal waste production in Nile tilapia (Oreochromis niloticus L.) (2005)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 36 (2005), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The physico-chemical properties of nutrients influence the physical characteristics of faeces and thus may affect waste removal efficiency. The aim of this study is to assess the effect of type of non-starch polysaccharide (NSP) on digesta viscosity, faeces recovery and nutrient digestibility in Nile tilapia. Insoluble (cellulose) and soluble (guar gum) NSPs were included separately and combined at a level of 8%, thereby formulating four experimental diets. The diets were assigned to 16 tanks with 35 fish each, with four replicates for each diet. Cellulose inclusion did not influence digesta viscosity, growth and digestibility of protein and starch and tended to increase faeces recovery (P=0.06). Guar gum inclusion increased digesta viscosity and reduced the growth and digestibility of protein, fat and starch (P〈0.01). Faeces recovery was reduced by 42% in diets containing guar gum. There were interaction effects (P〈0.05) between cellulose and guar gum for the growth and feed conversion ratio, indicating that cellulose alleviated the negative impact of guar gum. In conclusion, dietary soluble NSPs increase organic matter load in the culture system through a reduction in faeces recovery and nutrient digestibility, whereas insoluble NSPs improve the removal efficiency of particles by increasing faeces recovery.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.2005.01330.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Digestibility, faeces recovery, and related carbon, nitrogen and phosphorus balances of five feed ingredients evaluated as fishmeal alternatives in Nile tilapia, Oreochromis niloticus L. (2004)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 35 (2004), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: This study shows that alternatives for fishmeal in a fish diet affect not only fish growth but also faeces stability and nitrogen (N) and phosphorus (P) waste production. Wheat gluten diet (WGD), soybean meal extract diet (SBE), soybean meal diet (SBM), duckweed diet (DWD) and single-cell protein diet (SCP) were evaluated as a fishmeal replacement on a 15% weight weight−1 basis in tilapia diets. Fishmeal replacement affected dry matter (dm), protein, ash and P digestibility significantly. Faeces recovery (6.8–11.2%) was not significantly affected, although the amount of non-recovered faeces and total faeces showed significant differences. Duckweed diet and SCP resulted in the largest amounts of non-recovered and total faeces (199–210, 224–225 g dm kg−1 feed dm). Compared with fishmeal diet (FMD), the WGD and SBE resulted in similar growth, but higher non-faecal N losses (471–495 vs. 416 g N kg−1 N). Soybean meal diet, DWD and SCP resulted in lower growth but less non-faecal loss (409–450 g N kg−1 N). The DWD and FMD had the highest N retention (480 g N kg−1 N) compared with the other diets (431–451 g N kg−1 N). Carbon retention, faecal and non-faecal losses and P retention were similar for all diets (302–358, 142–176 and 489–523g C kg−1 C, 606–704 g P kg−1 P). Phosphorus faecal loss was lower for all diets (329–381 g P kg−1 P) than for the FMD (401 g P kg−1 P).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.2004.01179.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Growth, feed utilization and nutrient digestibility in tilapia fingerlings (Oreochromis aureus Steindachner) fed diets containing bacteria-treated coffee pulp (2002)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 33 (2002), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The effectiveness of bacteria treated-coffee pulp (BT-CoP) in fish diets was evaluated in a feeding trial with Oreochromis aureus (Steindachner) fingerlings. Five diets were formulated to contain 0%, 6%, 12%, 18% and 24% BT-CoP, replacing wheat meal. Fish were reared in a recirculating unit consisting of 16 aquaria. Each aquarium was stocked with 10 fish of 1.1–2.4 g. Fish were fed ad libitum twice daily (10 and 15 h) for 4 weeks. Fish fed diets without BT-CoP and with 6% BT-CoP showed similar growth (body weight, growth rate: RGRm) and feed utilization (feed conversion ratio, protein efficiency ratio, apparent net protein utilization). Diets containing 0% and 6% BT-CoP gave similar dry matter and protein digestibility coefficients, but dietary BT-CoP levels higher than 6% produced lower digestibility values, except for carbohydrate. It is concluded that O. aureus fingerlings may assimilate only small amounts (6%) of BT-CoP in the diets without adverse effects on growth and feed utilization parameters. The CoP-containing diets did not affect fish survival (100%). The depression in tilapia performance may be associated mainly with the high level of fibre present in the CoP diets.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2109.2002.00655.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Comparison of faecal collection method with high- and low-quality diets regarding digestibility and faeces characteristics measurements in Nile tilapia (2005)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 36 (2005), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The need for unbiased digestibility estimation has led to the development of a number of faeces collection methods. However, there is still a large variation in apparent digestibility coefficient (ADC) of diet/ingredients between these methods. This study investigated the impact of dietary quality on ADC and faeces recovery measurements obtained by two faecal collection methods (Choubert and settling tank). The fish were fed five diets: a control diet as high-quality diet, two levels of dried duckweed (20% and 40%) and two levels of fresh duckweed (20% and 40%), which were added to the control diet, as low-quality diets. Apparent digestibility coefficient estimates were highly correlated (r〉0.95) between both faecal collection methods. For all diets the ADC estimates were higher when using settling tanks compared with Choubert collectors. For the control diet differences in ADC between two collectors were small, but by inclusion of duckweed these differences increased. The recovery percentage of faeces was not correlated between both faecal collection methods (r=0.22, P=0.41). The estimated recovery percentage of faeces by settling tanks was about three times higher than by Choubert. In conclusion, the differences in ADC and faeces recovery measured by two faecal collection methods depend on diet quality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.2005.01257.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Simulation of Nile tilapia (Oreochromis niloticus niloticus L.) culture in ponds, through individual-based modelling, using a population dynamic approach (2005)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 36 (2005), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: A simulation model for the production of the Nile tilapia (Oreochromis niloticus niloticus L.) for mixed- or mono-sex culture and for poly-culture with the African catfish (Clarias gariepinus Burchell 1822) or African snakehead (Parachanna obscura Günther 1861) is presented. The model is based on an exponential decay model used in population dynamics and follows an individual-based approach. The model consists of a tilapia sub-model representing population dynamics, growth and recruitment and a predator sub-model representing the predation process and population dynamics and growth of the used predator. The model was calibrated with data on mixed- or mono-sex culture of Nile tilapia and for poly-culture with the African catfish or African snakehead obtained in Congo Brazzaville and validated with similar data from the Philippines, Thailand and the Ivory Coast. The model visualized major underlying processes in tilapia farming and aspects for further improvement of the model; growth is one of the most sensitive input parameters and should be quantitatively related to feeding level and feed quality; length at first maturity and quantification of the recruitment of Nile tilapia has a relatively large influence and recruitment should be related to the length of the females; prey–predator relations are too coarse and should be more fine-tuned with the relation between prey size and predator size. Incorporation of these features would provide the basis of a model that can serve as a predictive and decision-making support tool.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.2005.01228.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Apparent digestibility coefficient of duckweed (Lemna minor), fresh and dry for Nile tilapia (Oreochromis niloticus L.) (2004)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 35 (2004), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Dry matter (DMD), protein (PD), ash (AD), fat (FD), gross energy (ED) and phosphorus (PhD) digestibility coefficients were determined for five different iso-N fish diets fed to Nile tilapia (Oreochromis niloticus). The control diet contained fishmeal (35%), corn (29%), wheat (20%), wheat bran (10%), fish oil (3%), diamol (2%) and premix (1%). Partial replacement of dry matter of fishmeal, corn grain, wheat grain, wheat bran and fish oil by 20% and 40% of dry matter of duckweed, in a dry and fresh form, was performed. Diets of treatments 1 and 2 included 20% and 40% of duckweed, respectively, in a dry form. In treatments 3 and 4, tilapia received formulated diets 4 and 5 in addition to 20% and 40% fresh duckweed providing the same amount of dry matter and protein as in control. The specific growth rates (SGRs) of tilapia were 1.51±0.07, 1.38±0.03, 1.31±0.06, 1.44±0.02 and 1.33±0.05, in control and treatments 1–4. There was no significant difference between SGR for the control diet and the diet with 20% fresh duckweed, while the other treatment groups had significantly lower SGR. All the treatment diets provide good values for feed conversion ratios (FCRs) and protein efficiency ratio (PER). Dry matter of diets ranged from 61.8% in treatment 4 to 85.2% in control. All the diets have high PD (88.4–93.9%) and high-energy digestibility (78.1–90.7%). Dry matter of duckweed were 66.8, 63.3, 45.8 and 28.3 in treatments 1 to 4 respectively. Protein values were 78.4, 79.9, 77.6 and 75.9, while ED values were 59.8, 60.9, 64.5 and 58.4 in treatments 1 to 4 respectively. Analysis of body composition shows that tilapia fed diets with duckweed contain significantly (P〈0.05) higher phosphorus and protein content and significantly (P〈0.05) lower lipid content. In contrast, tilapia fed control diet had a significant higher (P〈0.05) dry matter content and lower ash content.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.2004.01055.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The consistency of individual differences in growth, feed efficiency and feeding behaviour in African catfish Clarias gariepinus (Burchell 1822) housed individually (2005)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 36 (2005), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Individual variation in growth, feed intake and feeding behaviour has been previously recognized in several fish species. However, there is a lack of information regarding the consistency of such individual differences, which is important to understand the probability of a certain individual trait to be inherent, i.e. genetically linked. The goal of this study is to quantify the consistency of individual differences in growth, feed intake/efficiency and feeding behaviour in African catfish Clarias gariepinus (Burchell 1822). Forty-eight juvenile fish (58.9±0.4 g) were housed individually for 47 days and weighed every second week. The consistency of growth, feed efficiency (residual feed intake (RFI)) and feeding behaviour (total feeding time (TFT)) was determined using repeatability estimates. Fish exhibited pronounced individual variation in growth (CV=52.8%), feed intake (34.3%) and in the TFT (〉100%). The repeatability estimates were 0.55 for growth, 0.70 for feed intake, 0.49 for RFI and 0.81 for TFT. Individual differences in growth were mainly explained by individual differences in feed intake (∼80%). Individual differences in feeding behaviour contributed to explain differences in feed intake by affecting the RFI. With increasing TFT, the maintenance levels also increased suggesting that slow eaters were less efficient in feed/energy utilization. The results of this study indicate that individual differences in growth, feed intake/efficiency and feeding behaviour are consistent over time and therefore probably inherent. Moreover, this study may have implications on the use of feeding behaviour as a predictor of feed efficiency in juveniles of African catfish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.2005.01372.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Nitrogen budget and fluxes in Colossoma macropomum ponds (2005)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 36 (2005), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: This study quantified the accumulation of nitrogen (N) in the water column, sediments, fish and seepage water during a production cycle of Colossoma macropomum. By combining estimates of the deposition rates of uneaten feed, faeces and dead phytoplankton with measurements of N accumulation in the sediment, the rate of decomposition of organic matter in the sediment was estimated. The first-order rate constant for organic matter decomposition was 0.237±0.019 day−1. Total N recovery during the first weeks of the experiment was about 65%. Later, the N recovery was close to 100%. The cumulative recovery at the end of the experiment was almost 100%, meaning that the N budget in the system studied can be fully explained without consideration of N volatilization, due to either denitrification or ammonia volatilization. In the beginning of the growth cycle, the major flux of N was sedimentation. Intensive microbial degradation process occurred about 3–4 weeks later, leading to a release of inorganic N and an approach towards a steady state as to the accumulation of organic N. Feed was irregularly applied during the experiment but fish growth was constant, showing that the fish utilized detrital or planktonic feed during periods of low feeding. Nitrogen accumulated in the pond during periods of excessive feeding and was utilized by the fish during periods of low feeding. This cycling should be further studied and may be an important pond management technique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.2004.01174.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Inherent variation in growth efficiency of African catfish Clarias gariepinus (Burchell, 1822) juveniles (2005)
    Oxford, UK : Blackwell Science Ltd
    Aquaculture research 36 (2005), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Understanding the major causes of growth variation is crucial for the success of fish farming since its reduction contributes to maximize production efficiency, reduce food waste and improve water quality. The growth variation observed in aquaculture has been associated with the establishment of social hierarchies. However, some studies suggest that this variation may not be mainly a consequence of social hierarchies but mainly a result of inherent (genetic) differences. This study investigates the magnitude of individual responses, independently of group effects (fish housed individually), in growth efficiency and feeding behaviour of African catfish Clarias gariepinus (Burchell 1822). Despite the low variation in initial body weight (6.5%) and cumulative feed consumption (7.5%) over the experimental period, catfish exhibited high variation in final body weight (18.1%), specific growth rate (17.2%) and feed conversion ratio (27.9%), suggesting that individual variation in growth efficiency is important in determining growth rate. This individual variation may be related with individual differences in protein/fat deposition since faster growing fish deposited more protein and less fat than slower growing fish. Pronounced individual differences in feeding behaviour (reaction towards feed and time spent eating) were also observed and correlated with individual differences in growth efficiency. Fast eaters were the fast growers. We suggest that the growth variation observed in African catfish may be inherent and that the use of grading to increase uniformity should be further investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.2005.01295.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The Development of a Functional Digestive System in the African Catfish Clarias gariepinus (Burchell) (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of the World Aquaculture Society 23 (1992), S. 0 
    Details
    ISSN: 1749-7345
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The morphological and physiological development of the intestine, stomach, liver and pancreas of the African catfish, Clarius guriepinus (Burchell 1822), was investigated from hatching until 9 days after the start of exogenous feeding by histological, histochemical and immunohistochemical procedures. During the yolk sac period, lasting 48 hours at 30 C, the digestive system develops from a rather undifferentiated system into a distinct liver and pancreas and a segmented intestine (parts I to III). Insulin and glucagon producing cells were clearly found in the endocrine pancreatic islets from 14 hours after hatching onwards, while at the start of exogenous feeding, the exocrine pancreas showed an intense zymogen colouration. Exogenous feeding started three days after fertilization, i.e., 48 hours after hatching. At that moment, the rearing temperature was lowered to 27.5 C. The first day of feeding was referred to as day zero, changing into day 1 when the first 24 hours of feeding were completed. From the start of exogenous feeding onwards, aminopeptidase, non-specific esterase and ATP-ase were detected in the digestive system. Morphologically, the stomach was completed at day 4 of exogenous feeding. Gastric acid secretion started on day 4 and lead to a pH below 3.3 in the stomach on day 5. During the first four days of exogenous feeding, C-t-gastrin immunopositive cells were found throughout the gut, including the gastric epithelium. After day 4, the C-t-gastrin cells were only detected in the anterior intestine. The completeness of the stomach development was also marked by the appearance of non-specific esterase activity in the stomach epithelial cells on day 5. All data together clearly indicate that in Clarius gariepinus, the ontogeny of a functional digestive system has been completed on day 5 after the start of exogenous feeding, marking thereby the end of the larval period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-7345.1992.tb00792.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...