Sometimes some newly hatched chicks show a malfunction of the neck, resulting in a bended neck, normally forcing the head to face upwards. This phenomena is called twisted neck, wry neck or star gazers, for obvious reasons. If it is observed its normally not a great number of chicks, but the chicks that have the abnormality are very easy to recognize. 

Although in literature there are several causes mentioned (like trauma, tumors, bacterial or viral infections), we normally relate it to a deficiency of thiamine (vitamine B1). This can be caused by a deficiency in the diet in the breeders, but also as a result of contamination with mycotoxins. As vitamine B1 is water soluble, the bird has little reserves for it and need a continues supply through feed or water.