I am no fan of pellets. The reasons for my critical view of this very common dietary staple for parrots are outlined, below. Of course, there are some exceptions in which pellet feeding does make sense in my opinion. These I have also outlined below.
Contra
1. Ingredients
Pellets generally have the same ingredients as found in standard seed mixes: corn, millet, peanuts, sunflower seeds, etc. Thus, initially, they are neither better nor worse than seed mixes – just a lot more expensive.
2. „Cooked to death“
The manufacture of pellets requires as a rule high temperatures and pressures. Even so-called low-temperature processes still use fairly high temperatures. This may destroy important components, such as vitamins and enzymes. At the end of the manufacturing process, synthetic vitamins and minerals are added again. But these by far cannot replace all nutrients found in fresh foods
3. Lacking
Since not all nutrients destroyed during manufacturing can be replaced, a pure pellet diet is lacking and will lead to nutritional deficiencies over time. Nevertheless, manufacturers recommend that the pellets should be fed exclusively or almost exclusively.
4. Boring
Pellets are always the same. This is terribly boring for our birds. In capitivity food is an important aspect in relieving boredom and keeping our birds occupied.
5. Synthetic vitamins
Synthetic vitamins, as used in the production of pellets, are controversial. The efficiacy of synthetic vitamins, is increasingly called into question by scientific studies. There are also concerns regarding side effects.
6. Undifferentiated
There are hundreds of different kinds of parrots. Within the same species there are old and young, healthy and ill, male and female individuals. The manufacturers of pellets, however, offer only very few different products. It is unlikely that the multitude of different animals can truly obtain fulfillment of their dietary needs through those few different types of pellets.
7. Overriding instincts
Living beings have natural instincts that will guide them to consume those foods which contain the nutrients they are in need of. Pellets make this impossible.
8. Parrots hull their food
Whether neccessary or not, parrots tend to hull whatever food they eat. Since the nutrients are usually applied to the outside of the pellets at the end of the manufacturing process, most of those nutrients will not end up inside the parrot, but on the cage floor.
9. Ideal growth substrate for germs
All ingredients going into pellets are ground-up. The pellets themselves are porous and the ground up ingredients offer a huge surface area. These are ideal conditions for germs to grow. While the raw material would be suitable for consumption for a long time, the pellets themselves, after opening, have only a short good-until date, unless they have preservatives added.
10. Dry as dust
Pellets are extremely dry compared to natural foods. Unfortunately, there are birds that do not drink enough to compensate for this. The result are health problems.
11. Expensive
Compared to the ingredients that pellets are made of, they are extremely expensive. If you chose to feed your birds with the raw ingredients instead of giving pellets, there would me more than enough money left in your budget for additional foods of high nutritional value, such as mangos or red palm oil.
Pro
1. Digestive problems
If a bird has significant digestive impairment, e.g. through PDD, pellets may be easier for him to digest than some natural foods. However, it is fairly easy to prepare fresh food that is easily digestible, on a daily basis.
2. Higher nutrition density than seeds
If parrot owners are not willing to make the effort of feeding their parrots a varied and nutritious diet, pellets are a better choice than a pure seed diet. At least the parrots will ingest some vitamins, albeit synthetic ones. However, this could also be accomplished by adding a vitamin/mineral mix to the seeds. This would at least provide the animals with something to do.
But I really hope, that you, dear readers, do not belong to that group of parrot owners, anyways.