Effect of Daily Feed Intake on Feed Efficiency of Juvenile Channel Catfish

• Published in: North American journal of aquaculture 2004-04, Vol.66 (2), p.100-104
• Main Authors: Li, Menghe H., Manning, Bruce B., Robinson, Edwin H.
• Format: Article
• Language: English
• Subjects: Ictalurus punctatus
• ISSN: 1522-2055; 1548-8454
• DOI: 10.1577/A03-024.1

Pond‐raised channel catfish Ictalurus punctatus fed to satiation typically have lower feed efficiency (the ratio of weight gain to feed consumption) than fish fed a restricted ration. It is not clear whether the reduction in feed efficiency of fish fed to satiation is caused by wasted feed or by less efficient feed utilization. Two studies were conducted using 110‐L flow‐through aquaria to evaluate the relationship among the feed intake, growth rate, and feed efficiency of juvenile channel catfish. In experiment 1, 20 fish averaging 46 g were fed once daily at 0.5% to 3.0% of body weight (BW) or to satiation for 2 weeks. In experiment 2, 15 fish averaging 37 g were fed once daily at 1.0% to 3.0% BW or to satiation for 4 weeks. Fish in the satiation group were fed as much as they would consume within 40 min, and the remaining feed pellets were removed and counted to determine the amount of feed consumed. In both experiments, weight gain increased as feed intake increased. Feed efficiency improved as feed intake increased and peaked at feeding rates of 100% and 89% satiation for experiments 1 and 2, respectively. The daily feeding rates required to maintain a constant BW were about 0.5–0.8% BW. The results from this study indicated that under controlled conditions, channel catfish most efficiently utilized feed when fed to satiation or close to satiation (without feed waste). This suggests that the reduction in the feed efficiency of fish fed to satiation in ponds is probably caused by wasted feed rather than by less efficient feed utilization by the fish. Pond‐raised channel catfish should be fed at a rate slightly below satiation without overfeeding to achieve optimum feed efficiency. Severe feed restriction may result in poor feed efficiency because a higher proportion of ingested feed would be used for maintenance in heavily stocked ponds.