* Corn as a main protein source is a poor choice. Use a brand of food that has a meat(not meat meal) as as the first ingredient.
* Chicken by-products meal is the dry ground, parts of the chicken carcass(after all good meat has been removed),such as necks, feet, undeveloped eggs, and intestines and sometimes heads and feet. It is of poor quality and hard to digest.
Several brands have meat as a main ingredient -check the labels. One should purchase a premium dog food with the best ingredients they can find and afford. By avoiding corn, preservatives, by products you will be on the right track. I can not give specific brand names - but there are many to choose from. Generally speaking you will not find a premium dog food sold in the grocery stores. While more expensive the caloric and higher nutritional value they have usually means you are feeding less product. Read labels for recommendations on the amount to feed your dog.
A great source of information about dog foods is The Dog Food Project
Pay attention to a label. Avoid dog food that has unclear list of ingredients like "Meat & Meat derivatives, Fish, Vitamins, Minerals" etc... They need to say clearly what type of meat is used for food production, what type of fish and so on. Look for a good quality dog food that has clear and precise labels.