a few articles on java and diet
http://www.efinch.com/species/java.htm Roy Beckham another well known finch expert, he has put a bit of time into studying species, their habits, breeding and especially diet.
"Diet
The Java Sparrows diet begins with a basic parakeet seed mix. You can use a standard finch mix, but these often contain a number of smaller millets that the Javas will ignore until the last large white millet is gone. You can also offer them just plain White Prosso and any other seeds in a separate dish. Javas will often seek out the oats in a Parakeet mix and will sift through the seed until they find it all. In a gravity feeder, this means they will drain the entire supply and scatter the seed looking for the oats. It is best to offer them and they will eagerly take egg food (Roy's egg food mix), gamebird crumbles and green food. I have never seen them eat live food, but suppose they could be enticed to if you really insist (but why feed livefood if you don't have to). Calcium can be provided in the form of crushed egg shell, crushed oyster shells or cuttlebone, but they are not normally enthusiastic about the cuttlebone. Despite their name, they really don't eat a lot of Rice. I have offered them Paddy Rice like I do all my Mannikins and Munia, but they are not as enthusiastic about this seed as some of the other Lonchura. They do like the Paddy Rice in a sprouted form."
from Garrie Landry one of our country's leading java breeders
"Proper care for Java Sparrows requires only a modest effort on the part of the keeper. In the wild state, Javas eat a tremendous amount of rice. Oddly enough, I have offered rice to my captive Javas and they showed no interest in it. The diet of Java Rice Birds in captivity is very simple. They adapt very well to the same diet preferred by Budgies (parakeets). A standard parakeet mix containing large white proso millet, plain canary seed, and oat groats is the basic requirement. The canary and millet can be in given equal proportions, or the percent of canary seed can be somewhat lower. Oat groats are relished and should comprise about five to ten percent of the mix, perhaps more in breeding seasons and winter months. A standard finch mix is also quite suitable for Javas, although I think they would prefer the larger seeds found in parakeet mix. I routinely give my Javas a soft nesting food several times per week during the breeding season and on rare occasions I offer them greens. They love both! My Java always have access to an aromatic finch mineral grit which I buy from Sunshine Bird Co. in Miami, Florida, and finely crushed egg shells, which I get daily from a local Chinese resturant. I mix the two in equal proportions. They consume tremendous amounts grit and eggshell, especially during the breeding season."
I raise many java different mutations and have a large flight and some breeding at all times.... things I have observed they love: hulled oats and groats, boiled grated egg, dried egg food mixes, they will take pellets, chopped kale, collard greens, carrots, squash, shaved broccoli, white proso, occasionally you will see them trying whole shelled safflower seeds. They love chitted quinoa when mixed in boiled grated egg. When breeding they go through massive amounts of food and require good proteins and a constant supply along with veggie chops offered daily. They do require a good vitamin mix. (just to caution you if you breed your java, clutches range from 6 to 10 so food for the young and lots of it is a must) Animal or insect protein is very different in composition than seed and veggie protein and the young need this to grow properly and strong.
Roy Beckham has mentioned his egg food recipe above...it is wonderful and you can adapt it to fit your birds needs....it can also be served in smaller amounts daily. Our vet recommends the animal protein for parents with young to provide them with a protein level of 20 to 25 % not to exceed 30%....non breeding should be between 12 to 19% daily. She personally discourages live food since in some cases and sources you can transmit parasites...if you do decide to use live food find a very reliable clean source. Java typically will not take to live food.
this site is set up a bit differently, you need to click on each food category....
http://www.javasparrow.co.uk/feeding.htm
http://www.javasparrow.co.uk/seed.htm
a good seed millet this leading authority in Europe uses is:
Panicum Yellow 12KG
Yellow Millet 8.25KG
Canary 4KG
Panicum Red 1.5KG
Red Millet 0.75KG
Niger 1.5KG
White Millet 2KG
additional seeds that can he offers:
Panicum Yellow 27%
Peeled Oats 27%
Japanese Millet 17%
Yellow Millet 10%
Red Millet 8%
Rape Seed 5%
Linseed 3%
Niger 2%
Canary 1%
he also recommends additional treat seeds... like millet strands (some soak these until the just start to chit the birds love it). he mentions Japanese millet...all my birds love this and a brown top mix.
Not sure if some of these seeds are available where you are, if so you may want to give them a try.