As one part of the program of the Department of Avian Sciences on cage-bird research, a flock of cockatiels is being used to investigate nutrition and physiology. This is a preliminary report on three nutrition studies.
EXPERIMENT 1 - This trial was designed to determine whether immature cockatiels would benefit from vitamin supplementation of the standard cockatiel seed mix, and whether symptoms of vitamin deficiencies would be observed as the experiment proceeded. No similar studies have previously been reported.
Three groups of eight birds each were used. They were 12 to 20 weeks old at start of the experiment. Two levels of the vitamin mixture were added to the water. These were calculated to supply 200 times and 20 times the turkey requirements of the vitamins based on an average water intake of 5 ml per day per bird. The third group, maintained on distilled water, received no vitamin supplement. All birds were given free access to the mixture of millet, canary, oat groats, sunflower and safflower. No mineral supplements were given to any birds. The original trial continued for 135 days. At the end of this period, the group given only distilled water (no vitamin supplement) was continued for a total of more than 230 days.
No significant differences were found among the groups in weight, behavior, appearance of feces, or feathering. A single bird in the distilled water (no vitamins) group showed weight loss from day one and died on day 57. On day 219 a bird in the same group accidentally received a laceration and bled to death.
From this study it appears that vitamin supplementation of a cockatiel seed mixture is not critical for continued maintenance of healthy birds, at least not over a four-month period, and that high levels of vitamins (estimates to exceed 200 times the requirement equivalent to poultry) are apparently not harmful. (Study carried out by Lourdes Aguirre and Mike Flathers).
EXPERIMENT 2 - The individual seeds that comprise common mixtures for maintenance nutrition were compared by using each of four seeds as the sole source of food for groups of young cockatiels. There was considerable diversity in the composition of the seeds used, as shown in this table of analysis of the kernels. The seeds fed were actually whole and unhulled.
PROXIMATE COMPOSITION OF THE KERNEL
Seed Moisture Crude Protein Crude Fat Soluble Carbohydrate Crude Fiber Ash
Canary 6.9 22.1 3.8 16.0 18.0 2.5
Millet 8.1 13.8 3.7 27.3 17.0 0.8
Sunflower 2.8 30.2 49.0 8.9 15.8 3.8
Safflower 3.0 23.7 58.6 7.3 11.2 2.8
Four groups of five immature birds each were used. Their mean weight + S.D. was 87.3 + 11.6 grams. The birds were given access to mineral blocks and were supplemented with a commercial product (Vitapol) in the drinking water. The birds were weighted daily for the first 12 days, then every four days for the remainder of the 60-day trial.
Cockatiels fed the canary seed and millet gained weight steadily and appeared healthy. Those fed whole sunflower seed sustained an initial weight loss but within 10 days all but one had increased in weight. This bird continued to lose weight, so it was returned to the cockatiel mix, and it then resumed normal weight gain.
The cockatiels fed only whole safflower seed generally avoided it, sustained weight loss imediately, and displayed shivering. Two birds were returned to the mixed seed diet. They recovered and regained weight, but a third bird that was continued on the safflower seed died on day 33. The two remaining birds shivered constantly and fluffed their feathers but gained weight during the experiment:
Seed fed Mean body weight gain in 60 days
Sunflower 22.5 (4 birds)
Safflower 13.6 (2 birds)
Canary and millet seeds were satisfactory single sources of food for young cockatiels; sunflower seeds were satisfactory for four out of five birds. Safflower seed was not relished, and only two out of the five birds eventually ate enough to grow slowly. (Experiment performed by Mike Flathers.)
EXPERIMENT 3 — Because it is not possible to control diet composition effectively if a natural seed mixture is used, a study was made of the suitability of a purified diet for young cockatiels. Such a diet would eventually permit estimation of requirements for essential nutrients.
The diet was one that has been used successfully to feed mature Japanese Quail. It was pelleted to increase palatability. Five immature birds were fed the diet for 30 days.
The weights of the birds declined initially until the birds learned to eat the diet readily, but eventually they became acclimated. The mean initial weight was 116.7g; at 30 days it was 104.1 g. Control birds fed a seed mixture exhibited a similar fluctuation.
This preliminary study suggests that cockatiels can be maintained on a purified diet for at least 4 weeks, which is long enough to permit experimentation on the importance of some essential nutrients in their diets. Such studies will be undertaken in the near future. (Trial performance by Paul Martin.)