Frequent problems during handrearing and the influence of the handrearing formula on their occurence

1. Frequent problems during
handrearing and the influence
of the handrearing formula on
their occurence
Werquin G. DVM
Versele-Laga, Belgium

2. Introduction
handfeeding = artificial feeding method
indicated in some conditions
infant immunity system makes baby
birds very susceptible to disease
all preventive measurements should be
taken to prevent disease, also while
formulating handfeeding formulas.

3. Signs indicating health
problems
regurgitation, vomiting
cropstasis, retarded cropemptying
weightloss, retarded growth
development problems,
skeletal and beak deformities
listlessness, weakness,
loss of feeding response

4. Causes of problems during
handrearing
micro-organisms
– viral: polyoma, BFD
– bacteriological:
klebsiella, clostridia, enterobacter,
coli
– fungal: candida, aspergillosis

5. Causes of problems during
handrearing
environment
– temperature
– humidity
– hygienic conditions: bedding, space
– water source (tap water: chlorides !)

6. Causes of problems
during handfeeding
Feeding method
– food preparation
– temperature of the food
– frequency of feeding
– amount of food / meal
– feeding implements: spoon
or seringue

7. Causes of problems during
handfeeding
Handfeeding formula
– nutrient composition
(protein, fat, minerals, vitamins)
– other properties
»microbiological quality
»ph - organic acids
»feedconsistency - texture
»taste
»enzymes

8. 1. Microbiological quality
absence of mycotoxins:
(aflatoxins, ochratoxin A, zearalenon, vomitoxin)
normal bacterial counts in cereals:
– wheat: 2.8 x 106
– wheat meal: 3.7 x 104
normal count of fungal flora in cereals:
between 5 x 102 and 7 x 105 / g
heat treatment of food ingredients reduces micro-organisms
microbial infections are seldom apported by the food
ingredients

9. 1. Microbiological quality
presence of lactobacils:
– physiological in parentfeeding
– also beneficial in case of handrearing:
cause acidification of crop content:
stimulates growth of autochtonous
lactobacils
cause competition with pathogenic bacteria
not documented in parrots
well documented in poultry
(Impey, 1989, Edens, 1991, Parkhurst,
1991)

10. 1. Microbiological quality
microscopical evaluation of
handfeeding formulas:
food yeasts (f.i. brewers yeast)
often confused with
candida albicans!

11. GRAM STAINING - CANDIDA

12. BREWERS YEAST GRAM STAINING

13. 2. pH - organic acids
lower pH favorises lactobacils
inhibits gram- bacteriae
some organic acids also inhibit candida
yeasts:
treatment of candidasis with formic acid
(Wood, 1970)
supplementation of acids valuable
alternative for prophylactic use of antibiotic
and anti-fungal drugs

16. pH of cropcontent in baby
parrots
8
7
crop pH
6
5
4
parentfed parentfed handfed handfed
empty crop filled crop empty crop filled crop

17. Conclusions crop pH measurements
crop pH is not constant but ever changing
in parentfed birds:
crop pH drops significantly after feeding
natural nutrition of parentfed baby parrots
probably acid:
lactic acid from crop flora of parents
HCl regurgitated from proventriculus of
parents

18. Mode of action of organic acids
RCOOH
RCOO- H+
H3PO4 pH
Energy
H+
H+
pH
RCOO- H+
DNA Breakdown Re-establish pH
Energy losses

19. The effect of lactic acid, formic acid and
phosphoric acid against E-Coli (pH 5)
Pathogenic E. coli
10
K88:K91:O149
8
6
4
Generations / 4 hours
2
0
0 50 100 150 200 250
-2
-4
Phosphoric
acid
-6
Lactic acid Concentration (mMol / L)
-8
Formic acid
-10

20. 3. thickness - consistency of the
formula
modification by changing water content
= nutritionally not correct
thickness influenced by:
– gelatinisation of starch (heat
treatment)
– fibers (pectins, gums, etc)
increasing soluble fiber content
decreased regurgitation after seringue
feeding,
but reduced crop emptying

21. 4. Taste of the formula
taste = very important
(even with seringue feeding)
parrots prefer sweet taste
(sugar content)
bitter taste causes regurgitation or
vomiting
increased sugar content reduces
frequency of vomiting

22. 5. Supplementation of
enzymes
increase digestibility of nutrients
beneficial effect not documented in baby
parrots
efficiency widely accepted for poultry
parentfed chicks may receive enzymes
regurgitated from proventriculus, gizzard and
duodenum to crop of parents (Fisher and
Weiss, 1956)
enzymes used in Nutribird
handfeedingformulas:
amylase, protease, cellulase, aminoglucidase

23. Conclusions
Although infections in
babybirds are seldom
apported by commercial
handrearing formulas,
the formulation of these
products can influence the
frequency of health
problems including
infectious disease.

24. Conclusions
In handrearing formulas for baby
birds,
beside nutrient composition,
attention should be paid to following
properties:
pH of the foodmixture- use of
organic acids
microbiological quality - use of
probiotics
consistency - texture of the
mixture
digestive enzymes
taste

25. Conclusion
Additional research on the
function of
• lactobacils
• crop pH
• regurgitation of enzymes
is necessary to better
understand
the natural mechanisms
against infections and
digestive problems
in baby parrots.

27. THE INFLUENCE OF THE HANDFEEDING FORMULA ON THE OCCURENCE OF
HEALTH PROBLEMS IN BABY PARROTS.
G. Werquin DVM1
1
Versele-Laga, Kapellestraat 70, 9800 Deinze, Belgium
Handfeeding of baby parrots is becoming a widely used method to increase breeding results
and to obtain tame domestic birds. Baby parrots are very susceptible to health problems due to
their infant immunity system. Disorders and infections of the digestive tract are very common.
Signs indicating health problems are: regurgitation, vomiting, retarded crop emptying,
weightloss, retarded growth, listlessness or development problems. Besides micro-organisms
(candida, coli, klebsiella) and environmental factors, also the feeding method (temperature of
the food, feeding frequency, amount of food, feeding implements) and the composition of the
handfeeding formula play an important role. For the handfeeding formula, not only the nutrient
composition (e.g., optimal levels of protein, fat, minerals, vitamins) is determining. This paper
reviews some less documented, not-nutrient-related properties of the handrearing formula
which may influence the condition of the chicks.
It is evident that the handrearing food needs to be of good microbiological quality: absence of
mycotoxins (aflatoxins, ochratoxin, zearalenon, vomitoxin), low bacterial counts, low fungal
counts. However, microbial infections are seldom apported by the ingredients. During
microscopical examination (Gram’s staining) of the food, one should not confuse brewers
yeast or bakery yeast with candida. Supplementing with lactobacillus has been discussed as a
method to induce a natural competitive inhibition of gram-negative and other pathogenic
bacteria. Since the added lactobacilli are not autochtonous and therefore do not colonise as
well, they should be given daily in order to favor colonisation of autochtonous
microorganisms.
The supplementation of acids, seems to be an interesting approach in the control of microbial
growth. Also in normal physiological conditions, the production of lactic acid by the
autochtonous crop flora is a mechanism to inhibit pathogenic bacteria.
Especially some organic acids (e.g., lactic acid) are usefull: besides the production of a low pH
environment, they have a specific action on the microbial cell (pass across the cell membrane
in their undissociated form). Wood demonstrated satisfactory profylaxis against candida by
adding formic acid to the food.
The consistency of the formula is very important and has to be in function of the age of the
chick, feeding frequency, feeding instrument and environmental temperature. Besides the
water content, other factors such as the gelatinisation of the starch and the content of soluble
fibers (e.g. gums, pectins) influence the consistency. Controlling the consistency only by
changing the water content is nutritionally not correct. Especially formulas which are too thick
(often used to reduce the number of feedings) revealed to be dangerous because they slow
down digestion and increase the risk of deshydratation.
Attention should also be paid to the taste of the formula: a strong sour or bitter taste can cause
regurgitation and vomiting, even with seringe feeding. Furthermore, heat treatment and the
addition of digestive enzymes can increase digestibility of the food.
More and more breeders replace their home-made formulas with commercial, prepared
handrearing formulas. This tendency opens the way to investigate and optimize all these
factors in order to obtain formulas which not only provide optimal nutrition but also help to
prevent disease.
ABSTRACT BOOK ZOONUTRITION MEETING 1999 54