This thinking has some obvious flaws. This displacement of materials from the terrestrial ecosystem into the aquatic system disrupts the chemical cycling in each with resultant damage to both. A need for the replacement of lost materials in the terrestrial system. A pollution of the aquatic ecosystem with a burden of added nutrients. Pollution does not necessarily reduce the quantity of life, but the quality of life is definitely affected.
Manure is burnable.
There are more people in the world today who use cow manure for fuel than there are who use natural gas. The thoughts of barbecuing a steak or teriyaki chicken over a pile of burning chicken manure may not be too aesthetically pleasing, but there are other ways to use manure for fuel. A man from England uses pig manure converted to methane to run his automobile. It has been estimated that the daily output of manure from six pigs, when converted to methane, will meet the heating and cooking needs for an entire family. Animal manures have been recognized for centuries as valuable fertilizers for crops.