Number of Animals Killed to Produce One Million Calories in Eight Food Categories

"The idea that a vegan diet kills as many or more animals than a meat-based diet is sometimes used as a rationalization for consuming meat, and this idea serves to add uncertainty to the ethical case for a plant-based diet. In an attempt to help clear up this uncertainty, I have made estimates of the number of animals killed directly by slaughter as well as through crop harvesting in order to produce one million food calories from eight different categories of food."

Breeding chickens for meat results in vastly more animal deaths than any other food category.
Based on these figures if you want to change your eating habits in order to reduce animal suffering you should start by removing chicken and afterwords egss from your diet.
You can prevent the most animal suffering following a strict vegetarian diet and vegan lifestyle.