Really? Wow! Did not know that.... but does this also include the entire vegetable family that it falls into? Which would include kale or swiss chard, because those I give just as freely to my ducks. I've been playing around with the idea of growing amaranth for my ducks and chickens to nosh on next spring/summer.Never use spinach to Birds it blocks the body from absorbing calcium..I give Alfalfa hay to scratch through..Broccoli, mixed veggies thawed..Peas...I do not give my Chickens much other than their feed..They still come out and find green grass under the snow..