Well, let's see--animal therapy is used in healthcare settings simply because watching and being around goats (or pets in general) lowers stress level and blood pressure. Yet, blood pressure tends to rise as we age when vessels lose some of their flexibility/elasticity. Therefore, I am making the assumption that maintenance of a blood pressure within normal limits (and perhaps longer life) would require the addition of several goats every year. You do the math--more goats are always beneficial! Works as my excuse.