Any dietary changes should be undertaken gradually. An important concern is the bird's refusal to eat a "new" food, leading to significant weight loss. Weighing the bird (in grams) on a daily basis using a gram scale is the best method for monitoring adequate food consumption. Weight fluctuations greater than 10% are considered problematic. Even if provided with supplemental food, birds can starve while merely appearing to chew their food but not consuming it. Grinding the food into a fine powder is not the same as eating the food.
Monitoring droppings is an excellent indication of the amount of food the bird is eating. Prior to the diet change, the number and character of the droppings (color, amount, liquid, form, shape, lack of odor, staining) should be noted. Any change in the volume or number of droppings (usually a dramatic decrease in amount) indicates insufficient food consumption. Owners should not be confused by the appearance of wet droppings, which they may assume to be normal. Wet droppings usually have little fecal matter produced from food consumption. Wet droppings are often a sign of weight loss as fat and muscle are converted to energy and water. The character of the droppings will change as the bird consumes more formulated diet - they usually become more firm with a definite shape.
Some birds switch to a new diet with little to no work on the owner's part. Other birds are very selective about what they eat. Birds should not be left alone to select their own diets. Like human children, birds will often choose the wrong foods and "parental intervention" is required. The single most important thing you can do for your bird is to feed it right.
High Potency Coarse
Birds are notorious tricksters. Confirm the bird is really eating by weighing the bird (daily) and observing frequency, volume and color of their stools. Stools should never be hard, dark or infrequent. Once fully converted, items like dark green veggies, sweet potato and carrot may be reintroduced. Feed Harrison's at around 85% or more of the total diet with the remaining foods being the veggies mentioned above.
This method is best used in birds who's eating habits can be individually observed. Split birds up into different enclosures or rooms during this period if necessary.
Never starve a bird.