"A few years ago we had a vet speak at a club meeting. When I asked about food affecting canine fertility he remarked that dried peas are a common ingredient in dog food now and have been used by farmers for years as a birth control for cows." with this link: https://www.vettimes.co.uk/news/report-links-commercial-dog-food-to-declining-fertility/
Article on using birth control on wildlife:
Soy Infant Formula:
"It has been estimated that infants who are fed soya formula exclusively receive an amount of oestrogen equivalent to five birth control pills every day."
EU wont import our beef because of all the hormones:
"The European Union disagrees about the dangers and boycotts US beef, which is swimming in the hormones oestradiol-17, trenbolone acetate, zeranol and melengestrol." http://www.alternet.org/food/4-surprising-foods-packed-estrogen-chemical-linked-obesity-and-sexual-dysfunction