Cockerels are males age 1 day to 12 months of age. Cock is a male over 1-year-old. Stag is a male 5-11 months of age. Pullets are females age 1 day to 12 months of age, hen is over 1-year-old and straight run is a term for males and females mixed as they hatch and are not separated. Generally, 100 straight run chicks will give you 50 pullets and 50 cockerels as an average.