Birds & Lactose (Dairy)
Lactose, the disaccharide contained in milk, is a very poor energy source for avians because of an insufficient supply of lactase in birds to hydrolyze lactose into its components of glucose and galactose. Since birds cannot breakdown lactose, the gastrointestinal tract initiates an allergic or inflammatory reaction to the product. This can range from mild inflammation with no clinical signs to mild symptoms like diarrhea in moderate cases (laxative effect) or total blockage/enterotoxemia in severe cases.
Mild symptoms are often missed so owners will say “I feed lactose and my bird has no issues.” As the frequency or quantity of ingestion increases, the inflammatory process can lead to secondary bacterial/fungal infections, decreased gastrointestinal motility, or complete functional/foreign body obstruction, toxemia and death.
Most people feed their birds dairy to provide calcium; however, a better source of calcium for your bird is simply almonds which will not irritate their gastrointestinal systems. Birds love milk and cheese products because of the fat content, but most birds also love almonds. If your bird doesn’t, then other calcium-rich foods include kale, broccoli, watercress, and okra. Other excellent sources of calcium include cuttlebone, egg shell, and bone meal. If you’re worried about your bird’s calcium levels then start with a blood test so you know if there even is a concern.
The relationship of calcium, phosphorous, and Vitamin D3 is the most significant interaction between vitamins and minerals. A bird must have sufficient Vitamin D3 available for proper absorption of both calcium and phosphorus. Inadequate Vitamin D3 can result in calcium deficiency in an otherwise calcium adequate diet. Excess dietary levels of vitamins D3 can result in hyper calcification.
How do they get D3? Direct, unfiltered (as in no glass windows) unfiltered sunlight. Glass filters out the UV-B rays needed to synthesize D3 -- screens will filter a good portion of it. Depending on where you live you may be able to get outside time a good portion of the year. A healthy, well feathered bird can withstand lower temps if they gradually move to cooler temps (as an outside bird would). Don't take birds from a warm house to a cold outside cage. If it gets really really cold in the winter where you live then I would recommend some Avian lamps.