To cut a long story short, yes. But why the question?
Canthaxanthin, a naturally occurring red carotene is fed to chickens and fish as it can impart a colour to the skin and egg yolk. It is also a potent antioxidant and so could potentially help against certain cardiovascular and inflammatory diseases.
The European Commission received a request to deliver their scientific opinion on the safety and efficacy of canthaxanthin for chickens for fattening, chickens reared for laying, laying hens, other poultry, ornamental fish and birds. The request considers a synthetic version of the carotene.
The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) have considered the available data and consider the following doses safe: “8 mg/kg complete feed for laying hens, chickens reared for laying, reproductive minor poultry and breeder hens of ornamental birds; 25 mg/kg complete feed for chickens for fattening and minor poultry for fattening; 100 mg/kg feed for ornamental fish and birds (except breeder hens).”
So why the picture of the pink flamingoes? There striking colour comes from carotenes in algae either that they eat directly or in shrimp that have eaten the algae.