"As a new mom, Mother's Day has taken on a special meaning this year," Rooney wrote in an open letter as part of Farm Sanctuary's Mother's Day campaign.
She continued, "Raising our baby, River, has opened my heart to a whole new life filled with hope and more determination than ever to create a kinder and more sustainable world."
"I feel so fortunate to be able to nurture my son in all of the ways that nature intended and I wish all mothers in the animal kingdom could experience that sacred maternal bond with their young, devoid of exploitation by humans," Rooney added.
She went on to shed light on mothers in the animal kingdom, highlighting several "extraordinary" animals who "survived dire circumstances" and "healed from their traumas" against all odds.
Rooney then encouraged readers to symbolically adopt an animal through Farm Sanctuary's Adopt a Farm Animal Program in order to support the organization's work.
"As I celebrate my first Mother's Day, I hope you will join me in honoring all of the inspiring moms and maternal figures who've made a difference in your life," Rooney concluded.