FISHERY BULLETIN: VOL. 71, NO. 1 



chemical method (Hoffman, Westerby, and 

 Hidiroglou, 1968) was used. 



Table 5 shows the average results from all 

 analyses. The data showed that there were 

 higher levels of selenium in the Gulf product than 

 in the Atlantic coast product (2.59 ppm vs. 2.22 

 ppm) (Soares and Miller, 1970), However, the 

 corresponding fish meals from these two areas 

 (Kifer et al., 1969) did not contain significantly 

 different concentrations of selenium. This ob- 

 servation indicated to us that selenium is present 

 in greater concentrations in the water-soluble 

 portion of fish rather than in the water-insol- 

 uble solids,, and the higher levels of selenium 

 found in Gulf menhaden fish solubles may reflect 

 leaching from the relatively high selenium soils 

 draining into the Mississippi River or other local 

 environmental conditions. Further research, 

 however, may reveal other explanations for these 

 differences. 



Regardless of whether or not Gulf menhaden 

 solubles or Atlantic menhaden solubles are used 

 in feeds, a level of 2-2.5% will supply the min- 

 imal level of 0.05 ppm selenium in the diet based 

 on total chemical analysis. 



Availability determinations of selenium in fish 

 meal and solubles are now in progress. To date 

 there is some indication that this selenium source 

 is not as available as sodium selenite (Miller 

 and Soares, 1972; Scott, pers. Comm, to Morris 

 and Levander, 1970). 



VITAMINS 



The fat-soluble vitamins are present in small 

 quantities in condensed fish solubles. In con- 

 trast, the contents of the various water-soluble 

 vitamins are at least 50% greater in the con- 

 densed solubles than in fish meal. Fish solubles 

 are considered very rich sources for vitamin B12, 

 choline, niacin, and one or more unknown factors. 



Table 6 lists data from six reports on the vita- 

 min content of condensed fish solubles. The data 

 are somewhat spotty and are often labeled "con- 

 densed fish solubles" with little or no details on 

 its origin. The data are particularly deficient 

 in regards to the fat soluble vitamins, inositol, 

 pyridoxine, and folic acid. However, there seems 

 to be reasonable reliability in the values given 

 for the remaining vitamins. In particular, each 

 kilogram of solubles contains about 4,400 mg of 

 choline, 270 mg of niacin, 38 mg of pantothenic 

 acid, 11 mg of riboflavin, 0.5 /ug of biotin, and 

 440 fxg of vitamin B12. 



NUTRITIVE VALUE 



METABOLIZABLE ENERGY AND 

 NUTRIENT DIGESTIBILITY 



Metabolizable energy (ME) is the energy de- 

 rived from a feedstuff after subtracting from the 

 gross energy value the amount of energy lost 



Table 6. — Vitamin content of condensed fish solubles. 



1. National Research Council (1968). 



2. Hideo, Murayomo, and Yonose (1961). 



3. Lassen, Bacon, and Dunn (1951). 



4. Scott, Nesheim, and Young (1969:440). 



5. Ewing (1963:291). 



6. Murayama and Yanase (1960). 



260 



