ISSN:
1365-2109
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
Two feeding experiments were conducted to evaluate the ability of rainbow trout, Oncorhynchus mykiss (Walbaum), to discriminate the sufficiency of a single essential amino acid in diets using self-feeders. In experiment 1, 12 groups of 23–24 fish (initial weight; 25.3 ± 0.5 g) were acclimated to a casein-based low protein diet (crude protein, CP = 10%) for 2 weeks. They were then offered for 32 days a combination of two wheat gluten-based diets fortified by crystalline amino acids (CP = 40%), with a complete amino acid composition (complete) and a composition deficient in either methionine (Met-def) or lysine (Lys-def) (six groups per treatment). In the complete and Met-def diet selection groups, no specific preference for either of the diets was observed. However, in the complete and Lys-def diets selection groups, a preference for the complete diet increased gradually (P 〈 0.05, for the last 8-day period). In experiment 2, 12 groups of 21–22 fish (initial weight; 27.6 ± 0.5 g) were acclimated to a casein-based high protein diet (CP = 40%) for 2 weeks, and then the complete diet and one of the amino acid-deficient diets were offered alternately for 8-day intervals over 32 days (six groups per treatment). In the complete–Met-def diet groups, overall daily feed consumption (g tank−1) increased gradually, but that for the Met-def diet seemed nearly stable. In the complete–Lys-def diet group, feed consumption when the complete diet was offered increased, while it then decreased after the complete diet was replaced with the Lys-def diet. These results indicate that trout discriminate sufficiency of lysine in diets and regulate their feed consumption.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1046/j.1355-557x.2001.00007.x
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