Page 592 - WSAVA2018
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 25-28 September, 2018 | Singapore
flight feathers on the wings. Primaries may begin to develop before secondary feathers, but usually mature after them. Final feather maturity is usually not complete before the bird has weaned.
The eyes begin to open at 10–28 days and take several days to open completely. Most Australian and African parrots hatch with their ears open. The ears of Eclectus and South American species should be open within 2–3 weeks after hatching.
The normal crop should have some food in it at most times. It should not be over-distended, nor should it have significant amounts of air or gas in it. Rhythmic contractions of the crop should be visible in neonatal chicks, and the crop should nearly empty in 4–6 hours in all chicks.
In neonatal chicks the abdomen should be large and convex relative to the rest of the body. The liver may
be visible through the skin in very young chicks, and rhythmic contractions of the ventriculus should be visible. The duodenal loop may be visible. There should not be bruising or haemorrhage visible. As the chick grows, the abdomen reduces in size relative to the rest of the body.
Pre-weaning chicks should be either resting, sleeping or calling for food. As they get older, the chicks still spend a lot of time sleeping, but are more interested in their environment and in socializing with nursery mates. A feeding response (vigorous extension and bobbing of the head and neck) should be easily elicited by pressing gently at the commissures of the beak.
Hand rearing
Hand rearing can be done for several reasons: to increase production from rare or valuable species;
when the chick is orphaned; or in an attempt to make
a better socialised chick. Recent studies suggest that
the latter is not always achieved by hand rearing, but many aviculturists maintain that hand reared chicks make better pets.
The timing of commencement of hand rearing varies between the owner and the individual circumstances. Some chicks, artificially incubated, are reared from the time of hatch; others are left with their parents for 2-3 weeks and are ‘pulled’ for hand rearing just before their eyes open, while others are taken just before fledging and are then reared until ready to wean.
The frequency of feeding is dependent on the age of the chick:
1. Hatch to 1 week – every 2 hours
2. 1 week to 3 weeks – every 4 hours
3. 3 weeks to 6 weeks – every 6-8 hours
4. 6 weeks to weaning – every 8-12 hours
A variety of quality commercial diets are available today and it is uncommon to see ‘homemade’ recipes. The volume fed is between 8-12% of the chick’s bodyweight. The food should be mixed fresh for each feed and fed at approximately 41oC (normal body temperature for birds).
Weaning is a stressful time for both the chick and the hand rearer. The chicks will often start to refuse feeds and may regurgitate part of what is been offered, A good selection of a wide variety of foods should be available for the chicks at this time – formulated diets, vegetables and fruit – and intake of these foods monitored carefully.
Health determinants
As most companion birds are altricial (i.e. totally dependent on their parents or rearer and the environment), their health status is determined not only by their current environment, but also by the ‘input’ from their parents and how the eggs were incubated. We can divide these factors into three broad groups (see Table 1).
 Pre-laying factors
    Parental genetics become a major issue in the breeding of mutations, where closely related birds are mated to develop certain characteristics such as colour. Unfortunately, along with desirable characteristics such as new colour, undesirable physical characteristics, such as decreased body size or physical deformities, can also occur.
 The maturity of the parents will affect the size of the eggs laid, the immunity passed through the egg, and the number of eggs laid.
 The health of the parent birds can affect the chick via pathogens transmitted through the egg to the chick, and by the degree of transference on maternal immunity via the albumen and yolk.
  The diet fed to the parents, particularly the levels of calcium and vitamins, will have a direct effect on the vitality, development and health of chicks – even before hatch.
  Incubation factors
    Artificial vs. natural incubation: as a general rule parent-incubated eggs tend to hatch out stronger chicks. Advances in incubation techniques are, by and large, resulting in better chicks. However, skill and experience are required to match the results seen in natural incubation.
  Temperature, humidity and hygiene in the nest box or incubator will have direct effects on the development of the chick and its hatchability and strength after hatch.
 Care in handling of the eggs by either the parents or the incubator operator, as well as the frequency and degree of rotation during artificial incubation, can affect the degree of difficulty in hatching, as well as an effect on the incidence of malpositions.
 Post-hatch factors
     Temperature extremes can force the chick to divert resources from its growth and health towards maintaining a constant body temperature. Humidity extremes can predispose a chick to dehydration, respiratory infections and skin problems (e.g. toe constriction).
  Poor hygiene will substantially increase the concentration of pathogens (or potential pathogens) in the chick’s environment. With the chick’s immune system still developing, this creates a high probability of infectious disease.
 Although the era of homemade hand-rearing diets is passing, nutrition of the chick is still a major factor in the health of the chick. The practice of adding ingredients to a well-balanced formula (often based on anecdotal information from other aviculturists) can have major detrimental effects on the chick.
  Management of the nursery, in particular biosecurity and the quarantine of new chicks from different sources, will determine the likelihood of introduction of infectious diseases such as Avian Polyomavirus.
Table 1. Determinants of health for chicks
Detailed knowledge of hand-rearing practices, including weaning ages, can be obtained from reputable aviculture literature.

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