I second Gig's objections, as I have training and professional experience in the meat industry.
Here is some reading:
Feed conversion ratio (from wikipedia)
Feed Conversion Ratios Help Explain Meat’s Outsized Climate Impact
Feed-to-Meat – Conversion Inefficiency Ratios
The Ultimate Guide to FCR (Feed Conversion Ratio)
However this is not all gloom and doom:
Elon Musk is quite knowledgeable on matters of untapped potential.
Quite frankly that's how he made his fortune.
Here is some more reading for those who want to see how many more people can be sustained with the agricultural potential of our little planet:
Urban farms have huge untapped potential to fight hunger
Cropland’s untapped potential
The hidden gem: Exploring the untapped potential of food investments
Africa: Untapped potential for agriculture