Biological Availability of Calcium and Phosphorus in Menhaden Fish Meals

ALTHOUGH it is generally assumed that the calcium and phosphorus in fish meals are completely available to chickens, this assumption has needed experimental study in view of the variation in availabilities among inorganic mineral supplements (Gillis et al., 1951Gillis et al., 1954; Grau and Zweigert, 1953; Miller and Joukovsky, 1953; Motzok et al., 1956; Nelson and Walker, 1964; and Dilworth and Day, 1964). An erroneous assumption on this point can be especially critical when economic and nutritional considerations indicate the use of high levels of fish meal in poultry diets. If used in substantial amounts, fish meal can become the sole source of supplemental P and a major source of Ca. This study was therefore conducted to determine experimentally the biological availability of P and Ca in commercially produced menhaden fish meals—the fish meal manufactured in largest quantity in the United States. Ash analyses of bones taken from…