Hi there,
Welcome to the forums!
Well with the pigs and chickens he should be super happy (although goats and sheep would really make his day) as these dogs love to work and do what they were bred for. Once you introduce these animals with caution and careful supervision (being young and never exposed to them before there are chances he want to play with them more than protect), he will likely feel like he has found his mission in life and will stick with them like glue. Most Maremma dogs I knew in Italy were mostly used as livestock guardians and spent most of the time with the flocks. They were raised with them from a very young age. The occasional ones kept mostly as pets were the ones that had some issues that needed work on.
If he is chewing stuff, it may help to provide him with chew toys are are quite durable and that surpass in value the things he is chewing outside. So I am thinking along the lines of the KONG X-treme filled up with goodies, a Kong Wobbler filled with his kibble and Goughnuts. Although these toys are ranked as super tough, checking them out along with your dog every now and then is important because no toy can be deemed 100 percent safe and non-destructible. It also helps of course removing as much as possible things that he chews on for safety (to prevent problems such as tooth fractures, intestinal blockages).
At 10 months, your Maremma sheepdog is also in the adolescent stage, a time where exercise and mental stimulation are important. https://www.braintraining4dogs.com/members/archive/survive-dogs-adolescent-stage/ Brain games and daily walks for exercise, mental stimulation and continuing socialization are therefore important. Training is also important, although it needs to be varied enough and rewarding to keep the interest alive.