The word 'breediest' refers to the most fertile or productive in terms of providing offspring. Its antonyms would be words that describe infertility and unproductiveness. Some of the antonyms for 'breediest' are barren, infertile, sterile, unproductive, and nonreproductive. These words imply a lack of ability to produce offspring, which is the opposite of what 'breediest' represents.
Using these antonyms in the right context can help to create more balanced and effective writing. For instance, instead of only focusing on 'breediest' animals, one could also discuss the challenges faced by barren or infertile animals. This would provide a more comprehensive perspective on the subject at hand.