(I don't know enough about what's localy available in the different regions.)
A HINT for judging what can be alternative feeds:
Pigs are very similar to people
concerning what's HEALTHY food. (That's why I realy DOUBT using chicken fertilizer.) But DON'T follow what most people EAT, because most people don't eat healthy
(For instance rice bran and brown rice are MUCH healthier than white rice, which is unhealthy. And don't give them fried food
There are several plants counted as WEED, but are HEALTHY. For instance dandilion leaves (young, the old taste bad). They have BETTER nutrision than common legumes.
So concerning pigs ment to live LONG time for breeding, nutrision information for humans can give much interesting information. Some simplified we can almost think "If it's good for humans - then it's good for pigs". And the opposite too
Similar as humans, pigs need some different food depending of AGE.
As for people it's better to have some change in what's eating, BUT don't make biger changes fast, because the stomach can need some time to adjust.
For Pigs ment to live short time just for fatening, we don't need to think what's healthy LONG turm, but feed to get a good imune system. Then no/less meds are needed.
For instance garlic and ginger are good for the health, so eating SOME such are good, but not to much. Garlic can even replace some commersial meds at bacterial illnesses, then eating some MORE are a cure. Don't worry if more garlic make the stool some lose, because it go back to normal a few days after the cure ends.
And I asume pigs, who LIKE their food, grow faster
which is an other reason to switch food SOME sometimes, so they don't get tired of the TASTE. (Hungry eat "anything", but they grow faster if they want to eat some EXTRA.)
To test what taste and smell they prefer, you can let ALONE pigs CHOSE which bowl they prefer, although SOME are "habbit pigs"
so they will just chose what's they are used to.
