Dying is dirty business. Like getting born.
Haven Peck gives his son this truth while talking to him after coming home from a day of killing pigs at the slaughterhouse. His son asks why Haven always comes home so dirty even though he wears gloves and an apron. Like Haven says, this quote is short, sweet, and imbued with a country eloquence that hides its deep meanings. It is one of the things about life that Haven wishes to teach his son before he dies. He is really saying that though birth and death are both painful, they are parts of life that are inevitable and should be dealt with as such. He doesn't enjoy being dirty when he comes home, just as no one enjoys dealing with death, but he does it because he has to. Life and death are very closely related in A Day No Pigs Will Die. The chief example of this is when Haven and Robert have to kill Pinky so that they will have enough to eat during the winter.