Your moluccan cockatoo weighs, just under 2 pounds.
How much does a batch of chop weigh?
An eight of a pound”, a quarter pound?
It’s a quarter of your cockatoo’s body weight, how much are you expecting him to eat?
Re: “puree at night, which he only eats with brown rice”.
That’s because he likes the rice because of the texture and the carbs it provides.
Purée is an unnatural food substrate for birds.
Humans eat it with a spoon I don’t know how a bird would assimilate it.
The smoothies although all-natural, are very high in sugar.
Think about what sugar does to a toddler and you have the same jitters multiplied by about 10 due to a parrots digestive system and how it works.
The smoothies are working against you.
Feeding soy anything to a bird can easily contribute to aggression.
Milk is commonly used to make yogurt.
Birds are naturally lactose intolerant because they lack the enzymes to digest any milk-based product.
You may be giving your bird tummy aches because of all of this.
I would stop the soy yogurt.
Mangos and bananas are also high in sugar.
Catherine and I are on the Keto diet where we try to achieve almost zero sugar intake, one of the many reasons we don’t eat mangos nor bananas.
You can easily zap a couple of tablespoons of generic frozen mixed vegetables for about 20 seconds and serve it semi-frozen.
If he doesn’t like that, try serving warm vegetables.
He’s obviously a sugar junkie so start with peas which have a relatively high amount of sugar making it more palatable.
You’re also not making his food fun.
Your serving food to him and not making him work for anything.
Cover the bird food with toy parts and make them pick through the toy parts in order to get to the food.
I would also offer other foods in a bowl mounted next to the pellets to give him something more interesting to eat.
Big birds like moluccan cockatoos all should have a large “Little Tykes” style toy chest filled with all sorts of benign toys like lightweight bowling ball and pins.
Stuff that can be knocked over and or grabbed with one of his zygodactyl feet.
I’ve seen simple red Solo cups keep the cockatoo occupied for 10 minutes as they like to hear the echo of their voice from inside.
Last but far from least and probably one of the most important things you can do for your bird is to add full spectrum lighting no more than 6 inches away over his cage.
The lamp should be on a timer to provide 12 hours of light and 12 hours of darkness.