This project assesses options for sexing in chickens in hatcheries following changes in genetics that have resulted in the slow feathering female trait being no longer available breeding broilers. As a consequence, researchers in the areas of poultry nutrition are facing difficulty to perform effective and efficient studies. Other sexing methods are available and in-ovo sexing technologies are under development. However, whether these sexing approaches are practical for research purposes has not been assessed. Furthermore, the statistical power of experimental designs aimed at assessing the growth response of birds to low protein compared to normal protein diets using sex separated chickens or equally mixed-sex chicken is not fully understood.