You're taking the model of an industrialized first-world nation with 300 million+ people and applying it to a tiny space colony. Calling that apples vs. oranges would be an understatement.
If you disagree, tell me this: How many 30,000 lb. John Deere combines do you think will be sent with the first settlers?
And don't forget space - these would be domed colonies, so space would be absolutely critical. Here on earth humans have devised a way to raise food animals in a way that's (somewhat) reasonably efficient in terms of land used. But that method depends critically on armies of 30,000 lb. John Deere combines in order to produce sufficient quantities of feed crop without an enormous human labor input.
Goats provide:
Meat Milk Leather Bone Manure Farts Goat blood Useless baby boy goats
They eat. They eat far more calories than you'll ever get from them. Someone has to look after them, and that person also needs to eat.
Someone needs to grow the food for the goats, and for the goatherds, and that person needs to eat.
For a goat to produce milk it (like most mammals) needs a child to feed. Thus, you need at least one male goat for breeding. But male goats don't give milk. And they stink. And billy goats are just plain mean. So this stud-goat, stinky, mean, lazy thing, also needs food and care. And the birthing goat needs some attention. And if it's a male it's useless, so someone has to kill it.
All that time and effort, and all you get is goat meat and goat milk. Maybe some will think it's worth it, but other people would prefer using all that time and energy on a wider range of food.
> tell me this: How many 30,000 lb. John Deere combines do you think will be sent with the first settlers?
You have it backwards: Massive industrial farming makes things many times more, not less, efficient.
If that is worth it probably depends on how much goat milk is worth to you, how much the green crap is worth to you otherwise as compost, and how much goat crap is worth to you as fertilizer.
I don't think it would be worth it, but it wouldn't terribly surprise me if I were wrong.
We canna break the laws of (bio)physics, Jim.