Article 

Calcium in the Avian Patient

The most widespread mineral in the body, calcium is required for normal metabolism and bone mineralization.

Physiology

Calcium homeostasis is under the control of calcitonin, which is produced by the ultimobranchial gland, vitamin D, and parathyroid hormone. In laying hens, most dietary calcium is used for egg production. Rising estrogen levels promote increased intake of calcium supplements like cuttlefish bone and calcium-rich foods, however the quantity of calcium ingested daily is insufficient for the massive deposition of calcium required for eggshell calcification.

Article 

Expert Panel on Companion Bird Nutrition

In 1998, an expert committee met to discuss the nutritional needs of companion birds. The purpose of the meeting was to discuss and develop nutrient profiles for companion birds, focusing on profiles for formulated feed.

The expert panel developed maintenance guidelines for two broad groups of birds: psittacines and passerines (regardless of size or genus). These conservative, generalized guidelines are extrapolated from the National Research Council requirements for poultry and…