Mineral nutrition in fish. XXIII. Availability to carp of manganese contained in various types of fish meals.

Abstract

A feeding experiment was conducted to examine availability of manganese (Mn) contained in various types of fish meals (white fish meal, brown fish meal, and sardine meal with or without soluble). Fingerling carp weighing 4.3g in average were fed diets containing one of four kinds of fish meals as a sole protein source with different levels of supplementary Mn for 11 or 24 weeks at water temperature of 15-25°C. Growth and feed efficiency were poor in fish receiving the diet without supplementation of Mn in every kind of fish meal diet groups, and were effectively imporved by addition of Mn and reached a plateau when supplementation of Mn together with Mn in each fish meal at a level met the Mn requirement of carp.Thus the content of Mn in the diets derived from various types of fish meals is not sufficient without supplementary Mn for normal growth of carp, judging from the fact that feeding diets containing various fish meals as protein source without supplementary Mn induced poor growth, short body dwarfism and reduced Mn levels in vertebrae. The results have also shown that bioavailability to carp of Mn contained in different kinds of fish meals is very high, and is not affected by the content of tricalcium phosphate in diet.