It's crucial to monitor and analyse mycotoxin levels in the feed of racing pigeons (and all animals) to ensure their health and performance. The mycotoxins mentioned can indeed have harmful effects on animals, and avian, as described. 
Aflatoxins (B1, B2, G1,&G2 ):
These are produced by Aspergillus species fungi. Aflatoxin B1 is considered the most toxic. Prolonged exposure can lead to liver damage, immunosuppression, and even carcinogenic effects.
Deoxynivalenol (DON):
Also known as vomitoxin, DON is produced by Fusarium species. It primarily affects the gastrointestinal tract, causing vomiting, reduced feed intake, and immune suppression.
Fumonisin B1 and B2:
These mycotoxins are produced by Fusarium species as well. They can lead to a condition called leukoencephalomalacia in animals, affecting the central nervous system.
Ochratoxin:
Produced by Aspergillus and Penicillium species, ochratoxin can lead to kidney damage and immunosuppression.
T-2 and HT-2toxins:
These are produced by Fusarium species and can have a wide range of toxic effects on animals, including cell damage, immune suppression, and even death in severe cases.
Zearalenone:
Produced by Fusarium species, zearalenone can disrupt the reproductive system in animals and lead to reduced fertility.
Quantitative analysis using mass spectrometry is a highly effective method for detecting and measuring mycotoxin levels in feed. This allows for precise monitoring and helps ensure that the feed provided to racing pigeons is safe and free from harmful mycotoxins. Regular testing is crucial to catch any contamination early and take appropriate measures to mitigate the risks.
To further protect racing pigeons from mycotoxin exposure, it's also important to implement good storage practices for feed and maintain proper hygiene in their living environment to prevent fungal growth on feed.