Yes, the different manures have different contents, horses and cows are herbivores, and each one's contains different nutrients that get returned to the soil. Cats and dogs are meat eaters, so not nearly as useful for our gardens, and more unhelpful bacteria in it. It depends on what crop you are fertilizing, too. For Dad's rhubarb patch, he's get a wheelbarrow of bunny droppings from the family up the hill once a year, and the rhubarb is the envy of everyone around!
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