| abstract |
A feedstuff for laying hens, chickens for eating, fish or crustacea contains small amts. of neurospiraxanthine (I) and/or its esters as dyestuff. The (I)-esters are those from 1-4C alkanols, esp. ethanol. The feedstuff contains 1-150 ppm of (I) or its ester, esp. 1-15 ppm for laying hens and broilers, 10-150 ppm for fish and 20-150 ppm for crustacea. USE/ADVANTAGE - (I) and its esters cause pigmentation of the egg yolks, of the skin, meat and legs of broilers of the flesh of fish and of crustacea and of the shells. (I) and its esters are more effective than the previously used red carotinoids Carthaxanthine, Astaxanthine and citraxanthine and are easier to prepare than the first two as the introduction of the oxygen function(s) in the cyclohexene ring gives increased preparative expenditure. |