According to what Macaw breeders refer to as the Bible, The Large Macaws by Abromson, Speer and Thomsen, this baby is a lot lighter than where it should be at 24 days of age. I copied down what is listed in the book and the first column would be the age followed by average weight, minimum weight and maximum weight. I also added on the food volume list with the minimum first followed by maximum then the times fed, again, minimum and maximum.
You really need a scale that weighs in grams and not ounces to get a more accurate weight each day and weight in the morning after the first poop. and as someone stated, you need to record the weights each day.
These weights are for specifically the Greenwing
24 620.8 415.0 830.0 35 100 4 8
25 657.0 435.0 860.0 40 100 4 4
26 698.2 470.0 915.0 50 100 4 4
27 735.3 495.0 948.0 50 100 4 4
28 769.7 515.0 990.0 50 100 4 4
29 810.3 555.0 1012.0 50 100 4 4
30 848.2 600.0 1080.0 60 100 4 4
31 885.0 660.0 1105.0 60 100 4 4
32 921.2 660.0 1134.0 60 100 4 4
33 956.9 705.0 1165.0 60 100 4 4
34 984.2 725.0 1198.0 60 100 4 4
35 1012.1 750.0 1224.0 60 100 4 4
36 1038.8 785.0 1270.0 60 100 4 4
37 1069.8 810.0 1300.0 80 100 4 4
38 1096.4 815.0 1326.0 80 100 4 4
39 1119.1 840.0 1355.0 80 100 4 4
40 1145.5 880.0 1380.0 80 100 4 4
If you want me to copy and send the chart I can do that over the weekend and it lists the info up to age 120 days.
It is so very important to get that weight up to avoid the baby's growth from being stunted. I am not a breeder nor do I have experience to help you with this but if you do want help I can put you in touch with someone who has raised just about all the Macaws so let me know and I will contact her.