Seed Mixes & Formulated DietsSeed alone is a highly deficient, imbalanced foodstuff. Seed-only diets commonly lead to deficiencies of the following nutrients: lysine, sodium, manganese, zinc, iodine, iron, calcium, selenium, choline, available phosphorus, available niacin, riboflavin, pantothenic acid, and vitamins A, D3, E, K, and B12.6,7 Even oil seeds (such as safflower or sunflower) which are too high in fat may be lacking these and other nutrients (including: copper, biotin, lysine, and methionine).7 These sorts of deficiencies compromise the health and reproduction of adult birds,7 and may pose serious problems for young, growing birds. All-seed diets, therefore, should be avoided.7 Although formulated diets are a preferred substitute for seed in the diet,7 seed does not have to be removed completely from the diet, just restricted.2 Supplementation, however, should be offered to address the imbalances inherent in a seed based diet.
Carrot, spinach, and silver beet are a few good sources of most of the vitamins and minerals that are deficient in seed.7 However, because vegetables (as well as seeds, meat, and fruit) are extremely unbalanced and deficient in calcium,7 a calcium source should be available at all times, especially to growing and breeding birds. The calcium source needs to be almost pure to adequately make up for the fact that the phosphorus:calcium ratio, ranging from 5.6:1 to 9:1 in seed, is so skewed in traditional seed diets.2 (The recommended balance of phosphorus to calcium is 1:2.) To meet this requirement, calcium carbonate is considered to be a superior source of dietary calcium, and it can be found in cuttlefish bone, eggshell, and crushed oyster shell.2,7
To begin supplementing the diet, start the birds off on 3 parts of an appropriate seed mix and supplement in 1 part soft food5,7 (such as an egg mix or other nestling food). An "appropriate" seed mix is one which is designed for finches, but tailored to your birds' particular tastes, as certain species tend to prefer certain types of seed. In the tables below, an example seed mix is presented, as well as selected species' "favorite" seeds. Seeds should be frozen for 7 days directly after purchase (to kill any moth/beetle larva or eggs that may be present) and occasionally sprouted to test their viability. As an interesting tidbit of information: seeds show high digestibility rates of fat (97-99%) and starch (88-90%) in the passerine digestive tract.7
When using the table15 below, provide each type of seed separately so that you can gauge which seeds your birds prefer.
|Type of Seed
|Proportion in Mix
|Canary grass seed
The table of specific species' seed preferences will be added soon.
If at all possible, try to wean your birds off of seed and onto a high quality formulated diet. Quality pellets are available through Harrison's, Kaytee, and Lafeber's. Make sure you select a pellet which is formulated specifically for finches, and is preferably dye-free. Although formulated diets do not need to be supplemented the way seed does, ideally birds should be fed 70% pellets and 30% fresh foods.5 Because processed diets are so dry, birds consuming them may also show an increased intake of water, and will have slightly moister feces as a result.5 Formulated foods designed for companion birds are usually of excellent quality, so bacterial contamination due to the milling and packaging process is unlikely.5 Improper food handling, however, may be a source of contamination, so practice proper food hygiene and do not allow food to get wet or come into contact with sick birds, rodents, or insects.5 For tips on how to wean your birds onto a pelleted diet, refer to Introducing New Foods.