Don't forget the distinctive odor that allows you to tell if you have arrived near that love, even in complete darkness. Of course if the new biomass engine does not lack this feature it probably ruins it for any covert use.

Chickens are better for that purposes, since their excrements are some of the best fertilizer around. They also smell better than the goat.

Goat won't eat the grass uniformly. So you won't have a nice looking lawn. + unless you have a mansion with a huge lawn the goat will starve after a few months.