SCARES ET AL.: CONDENSED FISH SOLUBLES 



The diets in these experiments were balanced 

 for energ^% calcium, phosphorus, and total ni- 

 trogen. When fish solubles was added to the 

 diets, the total nonessential amino acid content 

 was balanced by adjusting the glutamic acid con- 

 tent, and the essential amino acid content was 

 balanced by decreasing the amount of the re- 

 spective crystalline amino acid in the diet. All 

 additions of condensed fish solubles produced 

 greater growth rates in chicks as compared to 

 the controls. 



One of the above experiments consisted of six 

 treatments with four variables (Table 10) fed 

 to day-old chicks (duplicate groups of 12) for 

 3 weeks. Diet 1 was our basic crystalline diet 

 with no added protein whereas Diet 2 contained 

 5.0% fish solubles. A significant growth re- 

 sponse was obtained by the addition of fish sol- 

 ubles. Diet 3 plus 0.5 ppm selenium (as sodium 

 selenite) did not give any growth response over 

 the control. Diet 4 containing 0.5 ppm selenium 

 plus 0.82% proline (which Graber, Allen, and 

 Scott (1970) suggest is an essential amino acid) 

 gave a slight but nonsignificant response in 

 growth. Similarly, Diet 5 with 0.5 ppm seleni- 

 um, 0.82% proline, and 5% gelatin protein re- 

 sulted in only a small growth response. Gelatin 

 was incorporated in the diets because earlier ex- 

 periments had shown that the presence of intact 

 protein was beneficial to the overall growth re- 

 sponse to crystalline amino acid diets. However, 

 when gelatin and fish solubles (Diet 6) were in- 

 corporated in the diet, there again was a sig- 

 nificant growth response that was similar to the 

 response obtained with only fish solubles. 



In a further experiment by Miller and Soares 

 (1972) Diets 5 and 6 as listed in Table 10 were 

 irradiated with 4.5 Mrad of gamma radiation 

 by the method described by Soares et al. (1971) 

 and were fed to conventional and gnotobiotic 

 White Rock chicks. The results (Table 11) of 

 an initial experiment indicate that condensed 

 fish solubles is capable of exerting a growth re- 

 sponse whether or not bacteria are present. It 

 should be noted that both groups of chicks were 

 housed under conditions making it possible for 

 the ingestion of excreta which most likely oc- 

 curred because of the type feeders used. There- 

 fore, these data may not be in conflict with those 

 of Harrison and Coates (1969) who observed 

 that germ-free chicks consuming sterile diets 

 intentionally contaminated with sterile fecal 

 matter exhibited growth responses when fish 

 solubles was included in the diet whereas similar 

 chicks fed diets with no fecal contamination 

 showed no response to fish solubles. 



SUMMARY 



This review shows that condensed fish solubles 

 (particularly those made from menhaden) is 

 quite rich in many essential nutrients needed for 

 livestock production. This is especially true if 

 the composition is expressed on a dry-matter 

 basis, since half of the product consists of water. 

 Most essential minerals and water-soluble vita- 

 mins are found in solubles in relatively high con- 

 centrations when compared with other common 

 feedstuff's. Fish solubles is highly digestible and 

 rich in energy (measured as metabolizable en- 

 ergy) and, if expressed on a dry-matter basis 



Table 10. — Growth response and efficiency of feed con- 

 version of chicks fed purified diets supplemented with 

 selenium, proline, gelatin, and fish solubles.^ 



Table 11. — Growth response of chicks for purified diets 

 containing selenium, proline, gelatin, and fish solubles.' 



2 Average w/eight (g) of 18 day-old chicks. 



3, * Means bearing different superscripts are statistically different 

 (P<0.ai). 



1 Miller and Soares (1972). 



-, 3 Means bearing different superscripts are statistically different 

 (P<0.01). 



263 



