Breeding Research indicates that grouping a single male with two or three females will generally give high fertility. When quail are kept in colony pens, one male to three females is sufficient and reduces fighting among males. Pair matings in individual cages also give good fertility. Fertility decreases markedly in older birds. Avoid mating closely related individuals, because inbreeding increases the incidence of abnormalities and can greatly reduce reproductive performance. For this reason, it is desirable to record hen numbers on the eggs, incubate them in groups, and permanently mark the chicks at hatch time.
Pedigree records can be kept by using commercially available wing bands or leg bands to identify quail of all ages. Quails can be identified temporarily by a little oil paint on the back feathers (not on the skin) or fingernail polish on the toes.
Pre-incubation egg care Successful quail propagation begins in the pre-incubation period. Eggs should be collected several times a day and stored at a temperature of 15°C; a household refrigerator is not satisfactory because it is too cold. Cracked eggs hatch very poorly, if at all. Best results are obtained when eggs are held no longer than 1 week before setting.
Quail eggs should be handled with great care as they are very susceptible to shell damage. The coloured egg shells of quail make candling difficult.
A dirty incubator or hatchery area is a major source of contamination and disease. Thoroughly wash and disinfect the hatching unit after each use with a quaternary ammonium compound or commercial disinfectant. Set only clean eggs, as dirty eggs are a source of disease or infection. Soiled eggs can best be cleaned with fine sandpaper or other abrasives — eggs to be incubated should not be washed.
Eggs should be fumigated after they are collected, but alternatively they can be fumigated within 12 hours after being placed in the incubator. Do not fumigate embryos that are between 2 and 5 days old. Fumigation procedures are as follows:
* Use 25 g of potassium permanganate and 35 mL of formalin (40%) for each cubic metre of incubator space.
* Put the permanganate in an earthenware or enamelware dish (volume ten times that of the ingredients), and add the formalin last. Avoid inhaling the fumes, or wear a suitable respirator.
* In forced-draft incubators, leave the fan running and the vents closed during fumigation; open the vents after 20 minutes.
* In still-air incubators, open the incubator and vent after 20 minutes.
* During fumigation the humidity should be high, and the temperature must be between 20°C and 30°C.
Incubation and hatching The incubation period for quail is 17–18 days, depending on the strain and the incubation procedures. Successful hatches depend upon a good understanding of incubator controls; study the manufacturer’s recommendations carefully, and save them for further reference. The two types of incubators generally available are fan-ventilated (forced-draft) and still-air machines. A forced-draft incubator is preferable, but a still-air machine works well if carefully operated. Some models are designed especially for quail. Japanese quail eggs can be incubated in any chicken-egg type of incubator, although the egg trays in some machines may need modifying. Eggs should be placed large end up in the setting tray. Fan-ventilated (forced-draught) incubators Forced-draft incubators should maintain an incubating temperature of 37.5° ± 0.3°C (99.5° ± 0.5°F) and a relative humidity of 60% wet bulb reading of 30° ± 0.5°C (86° ± 1.0°F) until the 14th day of incubation. Eggs should be turned every 2–4 hours to prevent embryos from sticking to the shell. On the 14th day, candle and remove any cracked eggs, infertiles and dead embryos. Transfer the eggs to hatching trays and stop turning. A separate hatcher should be operated at 37.2°C (99°F) and a relative humidity of 70% wet bulb 32.2°C (90°F). If the incubator is a combined setter and hatcher, it should be operated at a temperature of 37.5°C (99.5°F), but the relative humidity should be increased to 70% wet bulb 32.2°C (90°F) during hatching.
The hatcher should not be opened during the hatching process. If all recommended incubation procedures have been followed, the chicks may be removed on the 17th or 18th day of incubation.
Still-air incubators If a still-air incubator is used, normal incubating temperature is 38.3°C (101°F) for the first week, 38.8°C (102°F) for the second week and not exceeding 39.5°C (103°F) until hatching is completed. Temperature should be measured at the top of the eggs. Humidity should be less than 70% wet bulb 29.4°–30.5°C (85°–87°F) until the 14th day of incubation; it should then be increased to 70% wet bulb 32.2°C (90°F) until hatch is completed in 17 or 18 days. Maintaining proper humidity in small still-air incubators can be a problem; do not open the incubator more frequently than is needed to turn the eggs, and do not leave it open for long periods of time.
The eggs must be turned by hand at least three, and preferably five, times a day. A pencil mark on the side of each egg may help to ensure proper turning. It may be desirable to move eggs to different locations in the incubator in case the temperature is not uniform throughout. Newly hatched chicks often tend to sprawl in hatching trays. To prevent this, crowd the eggs into a small area or fasten cheesecloth to the bottom of the hatching tray before the chicks begin to hatch.