Embryonic Mortality in the Incubator

Rick Jordan

Abstract



As the interest in the propagation of Psittacine birds increases, manufacturers of products that used to pertain only to the poultry business are becoming more interested in the new market potential. The results are brooding units and egg incubation units that are designed specifically for parrots.

Many of the new designs are simple modifications to accommodate Psittacine type eggs and chicks rather than those of precocial type birds. Brooding modifications for altricial chicks incorporate the need for isolation from each other and to protect them from invasive bacteria or viruses. Egg incubator modifications must accommodate eggs in the natu- ral position rather than the vertical position used to hatch domesticated poultry.

These slight differences in the protocol and care for altricial birds has stimulated new design in nursery equipment. A new market has arisen from the need to breed parrots for the pet and breeder trade. No longer can the trade rely on unlimited imported stock. The captive parrots of the future will be domestically produced and breeders will rely on innovative ideas and new-found knowledge to increase productivity.

Early Embryonic Death

Eggs that die in the first few days of life are difficult to distinguish from infertile eggs. The telltale signs of fertility are evident if the ''germ'' or white speck on the yolk is examined very closely. The infertile egg will appear as simply a small white spot (blastodisc) on the yolk. The early dead embryo of a fertile egg will often appear as a white spot with a halo or ring around it (blastoderm).

Early death occurs for numerous reasons. Many of these are uncontrollable factors that cannot be changed or improved through better avicultural practices. Nutritional deficiencies or genetic incompatibility can cause these early deaths and it is impossible to distinguish one cause from the other. A properly maintained flock should produce a high fertility and hatch rate of eggs that are laid. Consistent infertility or early dead embryos may indicate a need for a change in nutrition. Sporadic pairings that yield many early dead embryos could indicate some type of genetic incompatibility and these pairs could be split and re-paired for better results.

One cause of early embryonic death that may be diagnosed by the "sharp" aviculturist occurs when the eggs spends an unusually long period of time in the uterus of the hen. During the breeding season, many hens will swell in the area of the vent as the egg is being shelled in the uterus. This swelling is usually noticeable on small or mid-sized birds. It is very difficult to see in macaws and cockatoos. The normal amount of time between the swelling and the laying of the eggs is about 48 to 72 hours.





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