And the third part of the answer is that even if cows were better than condos, this is a false choice. There are other proven ways to preserve open space without having to subject the land to cattle and its multiple impacts. First, let's look at the notion that somehow livestock production is a relatively harm-less activity. Livestock production is the number one source of non-point water pollution in the West. This has degraded many high quality watersheds, affecting aquatic ecosystems, and adding immensely to the cost of water purification for domestic use.
Livestock are one of the major factors in the spread of exotic weeds.
The soil disturbance caused by hooves and trampling has created ideal colonization habitat for weeds. Plus the continued grazing of desirable native species weakens their ability to complete with exotics for water, space and food. Cattle also often assist in the spread of weeds by carrying seeds in their fur or excreting them with their manure. Livestock consumption of grass and other fine fuels has altered natural fire regimes and by eliminating or weakening grass plants, has given trees and shrubs a competitive advantage that has led to overstocked forests and shrub invasion of former grasslands. Livestock are the number cause of riparian degradation in the West.