ARTIFICIAL INCUBATION AND HAND-RAISING

By Dr BSc, BVSc, MRCVS, MACVSc (Avian health)

With breeding about to start, we all know that sometimes things don’t proceed as smoothly as we might like. An abandoned egg or youngster can be a particularly frustrating experience for a fancier, particularly if it is from one of the more important pairs. For many of us, the only available option to try and save the youngster is to foster it under another pair. To have any real chance of success, however, there should be no more than 48 hours, and preferably 24 hours, difference in the reproductive cycle between the foster pair and donor egg or youngster. Of course, such a pair is not always available. This situation need not necessarily mean that the youngster will be lost.

In the past, if a foster pair was not available for an incubated egg or a young nestling, it was not considered practical to raise the chick independently. However, with the availability of relatively inexpensive incubators and nutritious artificial hand-raising diets, it really becomes the fancier’s choice as to whether or not he wants to save the youngster by taking over the role of egg incubation or rearing of the chick.

The situation is eased somewhat if the egg has not been incubated. If development has not started, the egg does not need to be kept warm to remain viable. Eggs can be stored for several days waiting for a foster pair to lay. Eggs should be stored in a cool, dry place with the pointed end up at approximately a 45?q angle and turned at least twice daily (alternating left and right). Once the foster pair lays, the stored egg can be placed under them and development will commence.

If no foster pair is available, artificial incubation should be considered. A number of ‘hobby’ incubators are available (with readily available brands being Brinsea, Novital, Multiquip and Masalles) through a number of outlets. Prices vary depending on the amount of automation but it is possible for between AUD$500 and AUD$1000 to buy one that not only maintains the correct temperature and humidity but also turns the egg. The temperature and humidity parameters used for chickens work well in pigeons (and indeed most bird species). Temperatures of 37.2 – 37.5?qC and humidity levels of 55 – 60% are suggested. Automatic turning devices will turn the egg up to 25 times per day. Incubation procedures for the bulk of the incubation period are relatively straightforward and rely only on regular turning and the maintenance of adequate temperature and humidity levels. This routine only changes 2 – 3 days before hatching when the egg should no longer be turned and the humidity is raised to 70 – 75% (either by increasing the exposed surface of water or by decreasing the ventilation in the incubator). Humidity is usually measured with a hygrometer. Incubators can sometimes be used as a useful stop-gap measure until a foster pair has been organized or alternatively their use can continue until hatching.

Once successful hatching has been achieved, if no foster is available to raise the chick, then both warmth and food must be provided artificially.

Heat can be provided by a converted incubator, a pet heating pad or a container (even a cardboard box is fine) with an incandescent bulb. If using a bulb, the heat can be altered by changing the height of the bulb above the chick, the wattage (strength) of the globe or using a thermostat. A temperature between 32?qC and 37?qC should be maintained. Newly hatched chicks do better at the higher end of the scale. Humidity is best supplied by providing a source of water near the heat source such as a small jar of water. Chicks that are too cold will become poorly responsive and feel cold to the touch, and when very cold start to display a reflex involving repeated opening of the beak. Hot youngsters also become poorly responsive and become a bright pink colour. Youngsters older than 7 days will also pant.

To feed the chick, an artificial beak needs to be created. This can easily be done by cutting off the needle attachment on the end of a syringe. Different syringe sizes are used as the chick grows. The regurgitation of the parents is mimicked by depressing the syringe plunger as the chick eats, as shown in the diagram. The diameter of the opening should be such that the chick’s beak is able to fit inside the tube opening and open up inside the tube body. The chick will then drink the hand-rearing formula in which its beak is submerged.

INSERT DIAGRAM HERE

For purposes of feeding, the growth period in the nest can be divided into four stages. Initially the hand-rearing formula must mimic ‘pigeon milk’. Pigeon milk is high in protein and fat, with a high water content. Carbohydrates are virtually absent. As the chick grows, the diet becomes progressively more similar to the adult diet. Gradually, the level of protein and fat decreases while carbohydrate and solid matter levels increase. A number of diets are commercially available. A commonly used brand is Roudybush (Dr Roudybush is an American vet who established and runs a bird food manufacturing company). Two suitable formulas are Roudybush Squab Handfeeding Formula (which is essentially a pigeon milk substitute) and Roudybush Formula 3. These and other similar diets can be purchased from specialist bird outlets.

The four stages are:

Stage 1:
Hatching to 4 days
Roudybush Squab Handfeeding Formula.
Diluted 2.2 parts water : 1 part formula by volume
Feed five to six times daily
Note: Some hatched chicks can survive off the resorbing yolk sac for 24 hours. Some people prefer to give an initial feed of either saline or Hartmann’s solution (available from vets or a pharmacist), particularly if the chick appears dehydrated (deep red and poorly responsive, more likely to occur with a prolonged hatching).

Stage 2:
Early growth, 5 – 7 days
Roudybush Squab Handfeeding Formula.
Diluted 1.5 parts water : 1 part formula by volume
Feed four to five times daily

Stage 3:
Late growth, 8 – 14 days
Roudybush Squab Handfeeding Formula.
Dilute 1 part water : 1 part formula by volume
Feed three times daily

Stage 4:
Fledgling, 15 days – weaning (28 – 30 days)
Roudybush Formula 3
Initially dilute at the rate of 1.2 parts water : 1 part formula by volume and reduce the amount of water as the chick ages.
Feed from 3 times daily down to once daily and start to provide normal adult seed mix.

Through all stages, it is a good idea to add a probiotic (eg Probac) to the dilution water for at least one feed per day.

And so, is it all worthwhile? From personal experience, it is a lot of work and the youngsters at weaning do tend to be slightly less robust than those that are parent-reared. Once weaned, however, and eating independently, they do quickly compensate and catch up and are certainly quite raceable. This procedure is, however, best reserved for those special youngsters. I guess it all depends on the value placed on that particular youngster by the fancier. It is nice to know, however, that the options of incubating and hand-raising are now practical ones.

Special thanks to Dr Danny Brown for some of the technical information presented in this article.