At the 31st Western Poultry Disease Conference, we reported on the difficulties we encountered in raising cockatiels using diets containing 5.0 and 6.7 percent solids (Roudybush et al., 1982). Chicks grew slowly and mortality was high. We now report on the responses of cockatiel chicks to higher levels of solids in the diet.
Materials and Methods
Eggs obtained from the flock of cockatiels maintained by the Department of Avian Sciences were collected daily, stored at 13.3°C (56°F) and incubated at 37.5°C (99.5°F) dry bulb and 29.4-30.0°C (85-86°F) wet bulb. Eggs were set each week during the 26-day collection period.
At hatching chicks were distributed into three groups so that each group contained chicks of approximately the same age. Fourteen chicks were used in each group.
Chicks were brooded in a Brower incubator maintained at 35°C (95°F) throughout the experiment. Each chick was kept in the incubator in an individual No. 2 paper bag with shavings in the bottom to absorb feces.
The composition of the dry diet is shown in Table 1. The dry diet was diluted with distilled water to 10, 20, or 30 percent solids. The diluted diets were coagulated in a microwave oven to prevent settling. In 20 and 30 percent diets, additional diluted diet was added to thin the mixture for easier feeding. Settling did not occur. The diets which were refrigerated between feedings were fed at. 37.8°C (100°F). Feeding was done from 6:00 AM to 10:00 PM using sterile, disposable plastic syringes. Chicks were weighed each morning when their crops were empty.
*Vitamin premix provided per Kg diet: 19,394
Soybean oil 37.5 IU Vitamin A, 4,363 IU Vitamin D3, 121 IU
Cellulose 50.0 Vitamin E, 4.85 mg Menadione, 14 ug B12,
CaCO3 10.0 9.70 mg Thiamin, 242.4 mg Niacin,
CaHP4·2H20 30.0 19.4 mg Riboflavin, 19.4 mg Pyridoxine,
NaCl 9.9 77.6 mg Pantothenic Acid, 4.85 mg Folic Acid
Choline Chloride (60%) 4.2 1.0 mg Biotin.
Corn Starch 605.1 **Mineral premix provided per kg diet:
Vitamin Premix* 1.0 297 mg MnSO4·H2O, 97 mg CuS04·5H20,
Mineral Premix** 13.1 20 mg Co Actate·4H20, 9 mg KIO3, 3970 mg
Soy Protein 235.2 MgSO4·7H20, 2973 mg KC1, 4950 mg
Methionine 4.0 K2HP04, 9 mg Na2, Mo04·2H20,
1000.0 0.66 mg Na Selenite, 120 mg ZnO, 644 mg
The growth curves from 1 to 35 days for cockatiel chicks fed 10, 20, and 30 percent solids are shown in Figure 1. Chicks fed 10 percent solids grew at less than half the rate of chicks fed 20 and 30 percent solids reaching only 33.5 grams by four weeks. By four weeks both the 20 and 30 percent solids groups had peaked in weight at more than 82 grams and had begun to decline to normal weaning weights of 70-80 grams. Growth of the 10 percent solids groups was comparable to 20 and 30 percent solids groups only during the first two to three days.
Mortality of the three groups is shown in Figure 2. In all groups there was significant early mortality. Six chicks died during the first three days on the 30 percent diet while four and two chicks died during the first day on 20 and 10 percent solids diets, respectively. In each of the 20 and 30 percent groups, only one additional chick died during the rest of the experiment. In the 10 percent group, six additional chicks died, all between 18 and 35 days. These chicks showed characteristic emaciation and often failure of the crop to empty preceding death.
Discussion and Conclusions
The tolerance and requirements for solids in the diet increased rapidly with age in the cockatiel chicks. In the very early stages of growth, a solids level of 10 percent reduced mortality compared to 20 and 30 percent solids. Whether an even lower level of solids would further reduce mortality could not be determined from these data. After three days of age the required level of solids in the diet exceeded 10 percent; and by five days of age, 30 percent solids promoted rapid growth. Levels of solids higher than 30 percent may be tolerated at some time during growth. There is an advantage to feeding high levels of solids in the diet since the number of feedings per day decreases as the level of solids increases.
Chicks fed 10 percent solids showed symptoms similar to those observed when 5.0 and 6.7 percent solids were fed by Roudybush et al. (1982). In our earlier work we observed large numbers of coliforms in the guts of affected birds. Since only chicks fed low-solid diets were affected, it appears that the high incidence of coliforms, the low rate of crop emptying, and the emaciation were responses to the nutritional deficiency rather than to a readily transmissible disease.
1. Roudybush, T., B. Watkins, and C.R. Grau. Some problems in hand raising
cockatiels. Proceedings of the 31st Western Poultry Disease Confarence. 162-