Tran Duy, A., Schrama, J.W., Verreth, J.A.J.
Feed intake and satiation in fish are regulated by a number of factors, of which dissolved oxygen concentration (DO) is important. Since fish take up oxygen through the limited gill surface area, all...
Tran Duy, A., Smit, B., Schrama, J.W.
The aim of this study was to gain insight into how Nile tilapia (Oreochromis niloticus) regulate feed and energy intake in response to diets low and high in starch and cellulose. It was hypothesized...
Phosphorus requirements of European eel Anguilla anguilla (2008)
Heinsbroek, L.T.N., Hariati, A.M., Schrama, J.W., Verreth, J.A.J.
Martins, C.I., Hillen, B., Schrama, J.W., Verreth, J.A.J.
Individual differences in maintenance levels have been related with energetically expensive processes such as aggression. This relationship is not fully understood as on one hand individuals with...
Adiposity killed the catfish' appetite (2008)
Heinsbroek, L.T.N., Rutjes, G.M., Schrama, J.W., Verreth, J.A.J.
Fish require relatively high dietary protein levels when compared with other farm animals. Because of the high price of protein and the environmental effects of nitrogen discharge, the protein...
Synchronising the availability of amino acids and glucose increases protein retention in pigs (2007)
Schrama, J.W., Heetkamp, M.J.W., Verstegen, M.W.A., Gerrits, W.J.J.
Leenhouwers, J.I., Verreth, J.A.J., Schrama, J.W.
Inclusion of cereal grains in fish diets may induce changes in digesta characteristics with possible consequences for fish performance. Especially viscosity characteristics of the dietary ingredients...
Heinsbroek, L.T.N., Hooff, P.L.A., Swinkels, W., Tanck, M.W.T., Schrama, J.W., Verreth, J.A.J.
To examine the effect of feed composition on changes in feed intake and subsequent feed utilization with age, five populations of European eel, with an average initial body weight of 5 g each fed a...
Soybean meal-induced enteritis in Atlantic salmon (Salmo salar L.) at different temperatures (2007)
Urán Carmona, P.A., Schrama, J.W., Obach, A., Jensen, L., Koppe, W., ...
This study evaluates the effect of temperature on the development of intestinal disorders when Atlantic salmon are fed soybean meal (SBM). In this study 20% of the dietary fishmeal was replaced by...
Leenhouwers, J.I., Ortega, R.C., Verreth, J.A.J., Schrama, J.W.
Soluble non-starch polysaccharides (NSP) present in cereal grains may affect performance of Nile tilapia through changes in digesta characteristics. The objective of this study was to investigate...
Hari, B., Kurup, B.M., Varghese, J.T., Schrama, J.W., Verdegem, M.C.J.
Water quality and shrimp production were monitored in extensively managed ponds which were fed a 25% (P25) or 40% (P40) dietary protein, each diet complemented with or without carbohydrate (CH)...
Bucio Galindo, A., Hartemink, R., Schrama, J.W., Verreth, J.A.J., Rombouts, F.M.
Lactobacilli are Gram-positive and catalase negative rods commonly found in lactic acid fermented foods and in the gastrointestinal tract of mammals and birds. Few studies have described lactobacilli...
Bolhuis, J.E., Schouten, W.G.P., Schrama, J.W., Wiegant, V.M.
The availability of a rooting substrate may profoundly affect behaviour and welfare of pigs. Apart from their actual housing environment, also the conditions present in early life and individual...
Schrama, J.W., Gerrits, W.J.J.
The efficiency of protein utilization for growth in preruminant calves is decreasing with increasing body weight. In contrast to calves weighing less than 100 kg of body weight, heavy preruminant...
Temperature and body weight affect fouling of pig pens (2006)
Aarnink, A.J.A., Schrama, J.W., Heetkamp, M.J.W., Stefanowska, J., Huynh, T.T.T.
Fouling of the solid lying area in pig housing is undesirable for reasons of animal welfare, animal health, environmental pollution, and labor costs. In this study the influence of temperature on the...
The effect of group composition on the welfare of African catfish (Clarias gariepinus) (2006)
Martins, C.I., Schrama, J.W., Verreth, J.A.J.
Within fish farming grading, i.e. the process of sorting to approximate size, changes the group composition from heterogeneous to homogeneous. Although this procedure is considered an acute stressor,...
Amirkolaie, A.K., Verreth, J.A.J., Schrama, J.W.
Higher faeces removal efficiency can help and reduce the negative impact of faecal waste on water quality and on the environment. Physicochemical properties of feed ingredients/nutrients may change...
Martins, C.I., Schrama, J.W., Verreth, J.A.J.
Despite the importance of feed efficiency and stress response in fish production, the number of studies focusing on the relationship of their individual differences has never been investigated. This...
Leenhouwers, J.I., Adjei_Boateng, D., Verreth, J.A.J., Schrama, J.W.
The objective of the present study was to investigate if dietary soluble non-starch polysaccharides (NSP) increase digesta viscosity, reduce nutrient digestibility and increase organ weights in...
Martins, C.I., Trenovski, M., Schrama, J.W., Verreth, J.A.J.
This study shows that in African catfish Clarias gariepinus feed intake (IF) is stimulated by the presence of conspecifics resulting in higher IF and growth rate. The feeding duration and the...
Bacteria of commercial diet : the preferences of Litopenaeus vannamei (2006)
Schneider, O., Cong, T.L, Sereti, V., Schrama, J.W., Eding, E.H., Verreth, J.A.J.
Faecal physical properties influence water quality in a recirculation system (2005)
Amirkolaie, A.K., Schrama, J.W., Duijster, N., Verreth, J.A.J.
Aanyu, M., Schrama, J.W., Verreth, J.A.J.
It is generally accepted that disrupting social hierarchy by size grading allow the smaller to grow better. However, many studies have shown a negative or no effect at all. This raises the question...
Schrama, J.W., Verreth, J.A.J.
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...
Amirkolaie, A.K., Eding, E.H., Schrama, J.W., Verreth, J.A.J.
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...
Amirkolaie, A.K., Leenhouwers, J.I., Verreth, J.A.J., Schrama, J.W.
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...
Individual coping characteristics, aggressiveness and fighting strategies in pigs (2005)
Bolhuis, J.E., Schouten, W.G.P., Schrama, J.W., Wiegant, V.M.
Individual pigs, Sus scrofa, differ considerably in how aggressive they are during encounters with unfamiliar conspecifics. We examined whether individual coping characteristics of pigs were...
Bolhuis, J.E., Schouten, W.G.P., Schrama, J.W., Wiegant, V.M.
Characterization of piglets based on the degree of resistance they display in a so-called Backtest is, to a certain extent, predictive of their coping responses to several challenges in later life....
Photoperiod affects growth, behaviour and stress variables in Clarias gariepinus (2005)
Almazán Rueda, P., Verreth, J.A.J., Schrama, J.W.
Short periods of light or no light (18D : 06L and 24D : 00L) resulted in an increased growth compared to extended periods of light (06D : 18L and 12D : 12L) in African catfish Clarias gariepinus....
Kies, A.K., Gerrits, W.J.J., Schrama, J.W., Heetkamp, M.J.W., Zandstra, T., ...
Positive effects of dietary phytase supplementation on pig performance are observed not only when phosphorus is limiting. Improved energy utilization might be one explanation. Using indirect...
Bucio Galindo, A., Hartemink, R., Schrama, J.W., Verreth, J.A.J., Rombouts, F.M.
A good probiotic strain should be able to survive the conditions of handling and storage to be delivered in high concentration to the host. That is especially important when stressful conditions are...
Aanyu, M., Schrama, J.W., Verreth, J.A.J.
The goal of this study is to evaluate the effect of size distribution on growth performance and feeding behaviour in juveniles of African catfish. Two thousand sibling fish were grown for 8 weeks...
Schrama, J.W., Verreth, J.A.J.
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...
The effects of stocking density on welfare indicators on African catfish (Clarias gariepinus) (2005)
Energievoorziening en -benutting. Varkensvoeding: nieuwe ontwikkelingen en praktijk (2005)
De basisprincipes van de energetische benutting van nutriënten worden behandeld. Hiermee worden de achtergronden van het huidige netto-energiewaarderingssysteem voor varkens toegelicht, alsmede...
Effects of carbohydrate addition on production in extensive shrimp culture systems (2004)
Hari, B., Kurup, B.M., Varghese, J.T., Schrama, J.W., Verdegem, M.C.J.
One indoor and one on-farm trial were conducted to evaluate the effect of control of carbon/nitrogen ratio (C/N ratio) by addition of carbohydrate to the water column in extensive types of shrimp...
Individual coping characteristics, rearing conditions and behavioural flexibility in pigs (2004)
Bolhuis, J.E., Schouten, W.G.P., Schrama, J.W., Wiegant, V.M.
Several studies suggest that classification of piglets early in life based on the degree of resistance they display in a so-called Backtest may be indicative of their coping style at a later age. In...
Effects of soybean meal on intestinal morphology of Atlantic salmon (Salmo salar L.) (2004)
Urán Carmona, P.A., Koppe, W., Obach, A., Jensen, L., Schrama, J.W., ...
C, N, P balances of five feed ingredients evaluated as fishmeal alternatives in tilapia diets (2004)
Schneider, O., Amirkolaie, A.K., Vera-Cartas, J., Eding, E.H., Schrama, J.W., Verreth, J.A.J.
Almazán Rueda, P., Schrama, J.W., Verreth, J.A.J.
Little is known about the behaviour of fish under culture conditions. Several factors may have a direct effect on fish behaviour and its variations during the day. This study assessed the effect of...
El-Gohary, F., Verreth, J.A.J., Schrama, J.W., Gijzen, H.J.
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...
Backtest type and housing condition of pigs influence energy metabolism (2004)
Geverink, N.A., Heetkamp, M.J.W., Schouten, W.G.P., Wiegant, V.M., Schrama, J.W.
The behavioral response of piglets in a backtest early in life seems indicative of their coping strategy at a later age. Coping characteristics may depend on the interaction between backtest...
Comparison of feed preference of Litopenaeus vannamei fed SCP or commercial diets (2004)
Schneider, O., Cong, L.T., Sereti, V., Eding, E.H., Schrama, J.W., Verreth, J.A.J.
Schneider, O., Amirkolaie, A.K., Vera-Cartas, J., Eding, E.H., Schrama, J.W., Verreth, J.A.J.
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),...