1. Beta-carotene that is not converted into vit A serves a protective barrier against disease. 3. VITAMIN A DEFICIENCY Vitamin A utilized in the body is dependent on 1. Quantity stored in liver a. Deficiency symptoms appear in 1-2 years due to high amounts stored in liver 2.
Wild Lifespan. In their natural wild habitats, cockatiels, on average, live between 10 and 14 years, indicates Animal Diversity Web via the University of Michigan. Their average age for passing away is younger in the wild than it is in captivity. Captive Lifespan Cockatiels that are kept as pets -- or that live in other captive settings -- can stay alive for up to 25 years or so.
You should not breed cockatiels until the male and female are at least 12 months old, with a preferable cockatiel breeding age of 18 months.  http://bananariveraviariesindex.home...ockatiels.8 month old Cockatiel= 20 yr old young adult.  http://www.asabirds.org/Cockatiels.htm Cockatiels will mature at about 8 months of age, but it is best to wait until they are at least a year of age to start breeding them. .