Home About us Contact
|
Home About us Contact | ||
|
|
||
Specific Dynamic Action (specific + dynamic_action)
Selected AbstractsEffect of feeding level and feeding frequency on specific dynamic action in Silurus meridionalisJOURNAL OF FISH BIOLOGY, Issue 1 2005S. J. Fu The effect of feeding level (FL; 0·5 to 4% dry diet mass per wet fish body mass) and feeding frequency (once every 4 days to twice per day) on postprandial metabolic response was investigated in southern catfish Silurus meridionalis at 27·5° C. The results showed that there was no significant difference in the specific dynamic action (SDA) coefficient among the groups of different feeding levels (P > 0·05). The duration increased from 26·0 to 40·0 h and the peak metabolic rate increased from 207·8 to 378·8 mg O2 kg,1 h,1 when the feeding level was increased from 0·5 to 4%. The relationship between the peak metabolic rate (RP, mg O2 kg,1 h,1) and FL could be described as: RP = 175·4 + 47·3 FL(r2 = 0·943, n = 40, P < 0·001). The relationship between the SDA duration (D, h) and FL could be described as D=30·97FL0·248 (r2=0·729, n=40, P < 0·001). [source] Laboratory evaluation of two bioenergetics models applied to yellow perch: identification of a major source of systematic errorJOURNAL OF FISH BIOLOGY, Issue 2 2003P. G. Bajer Laboratory growth and food consumption data for two size classes of age 2 year yellow perch Perca flavescens, each fed on two distinct feeding schedules at 21° C, were used to evaluate the abilities of the Wisconsin (WI) and Karas,Thoresson (KT) bioenergetics models to predict fish growth and cumulative consumption. Neither model exhibited consistently better performance for predicting fish body masses across all four fish size and feeding regime combinations. Results indicated deficiencies in estimates of resting routine metabolism by both models. Both the WI and KT models exhibited errors for predicting growth rates, which were strongly correlated with food consumption rate. Consumption-dependent prediction errors may be common in bioenergetics models and are probably the result of deficiencies in parameter values or assumptions within the models for calculating energy costs of specific dynamic action, feeding activity metabolism or egestion and excretion. Inter-model differences in growth and consumption predictions were primarily the result of differences in egestion and excretion costs calculated by the two models. The results highlighted the potential importance of parameters describing egestion and excretion costs to the accuracy of bioenergetics model predictions, even though bioenergetics models are generally regarded as being insensitive to these parameters. The findings strongly emphasize the utility and necessity of performing laboratory evaluations of all bioenergetics models for assurance of model accuracy and for facilitation of model refinement. [source] Effects of dietary protein and lipid level, and water temperature, on the post-feeding oxygen consumption of Atlantic cod and haddockAQUACULTURE RESEARCH, Issue 2 2010Juan C Pérez-Casanova Abstract Tank respirometry was used to study the interactive effects of protein:lipid level (55%:11% vs. 42%:16%; both diets isoenergetic) and temperature (11, 6 and 2 °C) on the magnitude and duration of specific dynamic action (SDA) in juvenile Atlantic cod and haddock. The protein:lipid level did not affect any measured variable. However, numerous temperature and species effects were observed. For example, although the maximum post-feeding oxygen consumption (30,50% above routine metabolic rate; RMR) and SDA duration (,55,85 h; SDADUR) were not affected by temperature, SDADUR g,1 of food increased from 11 to 2 °C (from ,3 to 12 h g food,1). While absolute SDA (mg O2) decreased by ,60,65% in cod and ,75% in haddock from 11 to 2 °C, due to a concomitant decrease in food consumption from ,2.0% to 0.6% body mass, SDA comprised between 3.3% and 5.2% of the dietary energy content at all temperatures. Finally, RMR at 11 and 2 °C and SDADUR at 2 °C were 25,35% and 25% greater in cod, respectively, as compared with haddock. These results suggest that feeding reduced protein diets at low water temperatures is unlikely to improve the growth of these species. [source] | ||||||||||