Effect of feeding and fasting on excess post-exercise oxygen consumption in juvenile southern catfish (Silurus meridionalis Chen)

摘要

The impact of feeding (fed to satiation, 13.85% body mass) on excess post-exercise oxygen consumption (EPOC, chasing for 2.5 min) was investigated in juvenile southern catfish (Silurus meridionalis Chen) (38.62-57.55 g) at 25. Cutlets of freshly killed loach species without viscera, head and tail were used as the test meal, and oxygen consumption (VO2) Was adjusted to a standard body mass of I kg using a mass exponent of 0.75. Resting VO2 increased significantly above fasting levels (49.89 versus 148.25 mg O-2 h(-1)) in 12 h postprandial catfish. VO2 and ventilation frequency (V-f) both increased immediately after exhaustive exercise and slowly returned to pre-exercise values in all experimental groups. The times taken for post-exercise VO2 to return to the pre-exercise value were 20,25 and 30 min in 12 h, 60 h and 120 h postprandial catfish, respectively. Peak VO2 levels were 257.36 +/- 6.06, 219.32 +/- 6.32 and 200.91 +/- 5.50 ing O-2 h(-1) in 12 h, 60 h and 120 h postprandial catfish and EPOC values were 13.85 +/- 4.50, 27.24 +/- 3.15 and 41.91 +/- 3.02 mg O-2, in 12 h, 60 h and 120 h postprandial southern catfish, respectively. There were significant differences in both EPOC and peak VO2 during the post-exercise recovery process among three experimental groups (p < 0.05). These results showed that: (1) neither digestive nor exhaustive exercise could elicit maximal VO2 in southern catfish, (2) both the digestive process and exercise (also the post-exercise recovery process) were curtailed under postprandial exercise, (3) the change of Vf was smaller than that of VO2 during the exhaustive exercise recovery process, (4) for a similar increment in VO,, the change in Vf was larger during the post-exercise process than during the digestive process. (c) 2006 Elsevier Inc. All rights reserved.