[truebrazilian]

a lot of times pasture allows you to use marginal land that wouldn't be suitable for other cultures. Outside the developed world this happens a lot. In plenty of places there's not an option between corn and goats, but between inedible brush and goats. This doesn't apply too much to countries like the US, where cattle is feed with grains, that indeed could be consumed directly by humans without the energy losses created by the metabolic processes of raising said animals. But for free-range cattle in the less developed world, meat means having a biological factory to transform inedible cellulose into calories and proteins. And even for agricultural land of higher quality, suitable for crops, it is a good sustainable practice to alternate cultures with an occasional year of growing pasture, and letting cattle graze upon it and fertilize it with manure. So, the matter is more nuanced here. A big part of the problem are the subsides and non-tariff barriers that incentive farmers to raise cattle with feed on developed countries.

[JoeAltmaier]

Even in the US, many cattle are grazed on marginal lands, unsuitable for any other purpose.

[QuantumAphid]

This is true. Many people think that you can just get rid of livestock and grow kale. It doesn't work like that. Still others think you can get rid of livestock, which eliminates the need for feed crops, which then allows you to grow kale. That isn't reality either. Land with low-quality soils used to grow crappy field corn (which is not suitable for humans) cannot simply be converted to grow kale for humans.

Livestock are part of an integrated agriculture system. Livestock and agriculture depend on one another. Cattle and ruminants, for example, convert low quality wild scrub, fescue and leftover agricultural byprods into high quality human-edible meat and nutrients.

About 50% of the corn in the US is grown not for humans or animal feed, but to produce ethanol fuel. The residual of that ethanol process is then processed into feed for livestock.

Quite a bit of the Amazon region is used to grow soybeans. The soybeans are shipped to Asian countries where they make soybean oil out of it for cooking. The residual soy byproducts from that process is then turned into feed which goes to pigs and chickens in that region.

Also mentioned in an earlier reply that about 50% of all fertilizer needed for crop cultivation comes from animal manure and byproducts. The remainder (and alternative approach) is to synthesize the fertilizer from fossil fuels.

It's important to realize that livestock aren't simply a standalone component in the food system. They are a key part of the total agriculture picture.

Food also isn't simply calories, it's about nutrition-- getting absorbable animal-format vitamins, minerals, amino acids and other key nutrients. There are quite a few nutrients which are essential to the human body and yet are very difficult (some virtually impossible) to obtain from plant-only sources. So reducing meat does come with costs/risks in terms of nutrition, I think that shouldn't be overlooked.

[truebrazilian]

"Quite a bit of the Amazon region is used to grow soybeans."

Not that much. Most soy in Brasil come from the Cerrado region, a Savanah-like biome roughly the size of german and france, more or less south of the amazon rain forest. Second to that, the region of the states of mato-grosso, sao paulo and parana.

Soy is not much of a driver for amazon deforestation. The main problems there are illegal loggers, illegal cattle ranching and gold mining.

[QuantumAphid]

Brazil is the dominant food producer in the Western Hemisphere. I didn't mean to bring up soybeans with regard to deforestation (although it is a factor), I used the soybeans example to illustrate that livestock, agriculture and global demand are highly interconnected. There is very little that anyone outside of Brazil can do to tell Brazil how it should manage its land and resources.

Brazil to pass U.S. as world's largest soy producer in 2018 https://www.reuters.com/article/us-brazil-soy-usa/brazil-to-...

02-Jul-2019 USDA sees record soybean harvest for Brazil https://www.feednavigator.com/Article/2019/07/02/USDA-sees-r...

Brazilian Soybean Production By State https://twitter.com/kevinvantrump/status/956187342150266880?... https://ipad.fas.usda.gov/rssiws/al/crop_production_maps/Bra...