[rec.birds] Notes on Tom Rowdybush's nutrition lecture

jcz@sas.UUCP (John Carl Zeigler) (10/18/88)

Here are some notes from a lecture given by Tom Rowdybush
(PhD in Avian Nutrition from Univ. of Cal. at ?)
at North Carolina State School of Veternary Medicine
on Cockatiels.   Dr. Rowdybush sells a pellated parrot diet.

My wife took these notes, I thought the net might be interested.

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NUTRITIONAL NEEDS
Nutritional classes:  hatching to fledeging
                      maintenance
                      reproduction -egg laying, incubation,
                                    and chick feeding
Feed Content:                                      
                      soybean oil, crude
                      cellulose
                      CaCO3
                      CaHPO4
                      vitamins
                      minerals
                      choline chloride (60%)
                      isolated soybean protein (87%)
                      DL-methionine
                      corn starch
                      modified food starch
Vitamins:
                      B12
                      menadione
                      niacin
                      riboflavin
                      E
                      folic acid
                      thiamine
                      biotin
                      A
                      D3
                      pyridoxine
                      pantothenic acid
Minerals:
                      MnSO4*H2O
                      CaSO4*5H2O
                      Co(C2H3O2)2*4H2O
                      KIO3
                      MgSO4*7H2O
                      KCl
                      K2HPO4
                      Na2MoO4*2H2O
                      NaSeO3*5H2O
                      ZnO
                      FeSO4*7H2O

PROTEIN
high protein = high growth
optimun protein levels found to be 20%
Defficiencies cause growth depression and transient behavior
problems; from nervous, fidgetty birds to screaming, aggressive,
regurgitating birds.
Signs of protein defficiency: 
lg. head compared to body size
small, pink (unpigmented) feet
poor feathering
high mortality
excessive begging, biting
underweight
increased incidence of geardia and clamydia infections
                     
The best prevention is to weigh the birds regularily
and keep clear records.  Watch for lack of weight gain
rather than weight loss.  Cockatiels are capable of
maintaining a weight for a week at 0% protein intake.
The bird may be well into it's second week of a problem
before a weight loss is seen.

LYSINE
Optimum lysine levels are .8% of total food intake
A common cause for diagnosis of lysine defficiency
in poultry is acromatosis (lack of pigment). In 
cockatiels, however, those birds feed a lysine deficient
diet showed no signs of acromatosis.
Low levels of lysine tend to restrict growth.

CHOLINE
Acromatosis does occur in choline defficient diets in the form
of yellow areas in the tail and wing areas.  These birds
display acromatosis at choline levels that would be
considered lethal in poultry.

RIBOFLAVIN
Also causes acromatosis  (often diagnosed by abnormally
curled toes, but does not apply in cockatiels).

PANTATHENIC ACID
Defficiency causes sparse feathering on breast
and back area.

FAT
Abnormally high fat levels (62%) result in the same growth
rates as normal diets.  Birds have a greasy appearance,
and are more prone to a putrification process (similar
to sour crop) through increased bacterial growth.  The
condition results in a very strong odor and approx.
50% mortality rates.

A Word About The Sunflower Seed Argument
Sunflower seeds have been accused of containing an addictive
drug detrimental to avian health.  The substance in
question is papavarine, a smooth muscle relaxant poorly
absorbed by mammels, found in the opium poppy.  Tests 
carried out in forensic laboratories have found that,
if present AT ALL, papavarine is present in less
than .5 ppm (the smallest identifiable portion).
In making up a seed diet, you should be aware,
however, that the darker the seed, the higher the
fat content.

Single Seed Trial
When test groups of birds were fed diets consisting
exclusively of either white millet, canary seed,
sunflower seeds, or safflower seeds, the only 
diet found to be seriosly detrimental was the
safflower diet, which caused reduced growth
rates, trembling, and death.

The Vitamin C Discussion
Although some advanced mammals (humans, primates,
fruit-bats), gueinea pigs, an occasional passerine 
(red vented bulbo), and a few galliformes (willow
ptarmagin) require dietary vitamin C, it is generally
accepted that psittacines do not.

Water:Solids Ratios
Very young hatchlings have relatively small crops
and should be fed free choice (as opposed to force
fed) with a low water:solid ratio (7% solids)
until the crops have enlarged.  The mixture
should then be increased to 30% solid to increase
growth rates. 

Low solid syndrome includes:
poor weight gain
crops emptying at a lower rate
increased begging effort
complete crop shutdown
increasingly dark droppings
increased rate of crop infections
At this older age, feeding is facilitated by
holding the head of the bird and force-feeding
a measured amount of food.

Things To Aviod In The Avian Diet
Lactose- milk, whey
other simple sugars- corn syrup, sucrose,
                     honey, molasses
(can increase incidence of candida)

Causes Of Crop Stasis
yeast
diet too dilute
diet separation
mechanical damage
systemic infection
incorrect brooding temp.

Webby Feed
cause: moth larvae
cure: Bacillus thuringiensis (sold as Dipel or Thuricide)  
 
This bacteria causes an epidemic among the catepillars
so that uniform mixing is not critical.  Treat
with 125 ppm, or 1 tsp./50 lb. bag.  The spores
will not germinate below a pH of 9.0, and so
will not germinate in the GI tract of the bird.

Calcium Requirements For Egg Laying
Ca availability affects:
egg production
shell thickness
conductance (rate of water loss)
hatchability
Ca deposits can be removed from skeletal
bone, and high producing hens will do so
to their own deficit.  Requirements are
MUCH lower than previosly thought, max. 
1-1.2%, maintenance levels .3%

Seeds Vs. Pellets
There are three basic responses to the
introduction of pellets to seed eating
birds:  no weight loss
        small weight loss, quickly regained
        weight loss leading to death
There is a 90% acceptance rate at each introduction,
so all birds CAN be switched to a pellet diet.  It
is necessary for the bird to be made aware that
the pellet form is a food source.

Weaning
definition:  parent or hand-fed to self-fed
             a change in response to hunger
             (non-weaned hunger response - begging
             weaned hunger response - eating)
1) cockatiels begin eating at 3 1/2 weeks
2) feed restriction with food available = wt. loss, begging
3) protein restriction = wt. loss, diarrhea
Earliest weaning is found in birds that had the
most rapid growth rates, the criteria being that
the bird has maintained it's body weight for 3
consecutive days without being hand fed. 

COCKATIEL STATISTICS
adult wt.               80-110 g
egg wt                  5-8 g
clutch size             4-8 eggs
chick wt.               3.5-5 g
fledge                  4 weeks
wean                    7 weeks
sexual maturity         8-12 months

ENVIROMENTAL FACTORS AFFECTING REPRODUCTION
factors tested for:
photoperiod (max.)
light intensity (min.)
temp. (min.)
diet (min.)
presence of nest boxes (max.)
misters (min.)
Cockatiels are sensitve to refractoryness - stimulation
to breed has been present for a long period and
the birds no longer respond.  To induce breeding,
birds should be put through a winter period (short
day period) and then simultaneously exposed to a 
spring period (long days) and breeding boxes.

Summary:
1) stimulatory environmental conditions 
       a. increased % pair production
       b. increased clutch length
       c. increased egg production
       d. increased hatch wt.
2) environment exerts little influence on
       a. % of pairs inspecting nest boxes
       b. rate of ovarian developement
3) diet prior to environmental stimulas
   did not affect reproductive performance

Time elapsed between stimulation and egg laying
is fixed - approx. 14 days.

PARENT REARING VS HAND REARING REPRODUCTIVE PERFORMANCE
Worst possible pairing - hand raised male x parent raised female
Best -  parent raised male x hand raised female
The other 2 crosses produce mediocre results.

Summary
1) Rearing influence (hand vs. parent reared) strongly
   influenced adult sexual behavior
   a. pairs containing parent reared males were
      more likely to be fertile, inspect nest boxes,
      and therefore produce more chicks
   b. pairs containing hand reared females
      were more likely to produce eggs
2) The results may be due to a failure of hand raised   
   males to imprint on cockatiels as sexual partners
   and on nest boxes as nest sites. Likewise, the 
   greater egg production of handreared females
   may reflect how caretakers and experimenters
   are perceived.

MISC. NOTES
Pair-bonding can be broken and re-formed,
even in close proximity to the previous
partner, if the birds are put through a
refractory period (6 weeks) and introduced
to a new partner in the "spring".

Imprinting:  cross-fostering causes
courting of the foster species, unless
the foster species is not present, in
which case same-specie courting will occur.

Use drugs and treated foods only for specific
treatments and only under veterinary supervision, 
not as a cure-all, or preventative.

NOTES TAKEN FROM A SEMINAR GIVEN BY TOM ROWDYBUSH
NCSU SCHOOL OF VETERINARY MEDICINE, 10/8/88
SHARON Y ZEIGLER
-- 
--jcz
John Carl Zeigler
SAS Institute Inc.
Cary, NC  27511           (919) 467-8000        ...!mcnc!rti!sas!jcz