Is preparing eggs for a meal considered as sinful in Buddhism? When preparing a meal with eggs, If a person cracks a egg will it be bad karma? Because, It is considered that farm chicken eggs are not fertile or doesn't have chicks growing inside. Therefore will it give bad karma for making eggs?
I think the idea of sinful or not doesn't apply to Buddhism. There are only wholesome/skillful actions and unwholesome/unskillful actions.  Karma = intention.  

As long as you are mindful of what you're doing and your intention is to prepare a meal for nourishment, instead of causing harm in any way, cracking an egg during the meal preparation doesn't seem to be a cause for bad karma.