Applications 21-25


Guy Werquin DVM1
1 Versele-Laga, Kapellestraat 70, 9800 Deinze, Belgium

Hand feeding 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, weight loss, retarded growth, listlessness or development problems. Besides microorganisms (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 hand feeding formula play an important role. For the hand feeding 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 hand rearing formula which may influence the condition of the chicks. It is evident that the hand rearing 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 autochthonous and therefore do not colonise as well, they should be given daily in order to favour colonisation of autochthonous 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 autochthonous crop flora is a mechanism to inhibit pathogenic bacteria. Especially some organic acids (e.g., lactic acid) are useful: 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 prophylaxis 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 fibbers (e.g. gums, pectins) influence the consistency. Controlling the consistency only by changing the water content is nutritionally not correct. Formulas which are too thick (often used to reduce the number of feedings) have been revealed to be especially dangerous because they slow down digestion and increase the risk of dehydratation. Attention should also be paid to the taste of the formula: a strong sour or bitter taste can cause regurgitation and vomiting, even with syringe feeding. Furthermore, heat treatment and the addition of digestive enzymes can increase digestibility of the food. More and more breeders replace their homemade formulas with commercial, prepared hand rearing formulas. This tendency opens the way to investigate and optimise all these factors in order to obtain formulas, which not only provide optimal nutrition but also help to prevent disease.


Patrick Ghysels DVM1
1 Nutribird Products, Versele-Laga N.V., Deinze, Belgium

In the last ten years various companies in Europe as well as in the United States have formulated and produced bird foods in the form of extruded pellets. Conversion difficulties are an important barrier for using pellets by the bird owners. 1. Requirements for a successful food conversion. The breeder will need to receive professional advice from the veterinarian, other bird owners and breeders and the retail shop. Successfully converting a bird will mostly depend on the motivation of the bird owner. The perseverance of the bird owner will in fact determine the success of conversion. 2. The various conversion methods There are various conversion methods from which the bird keeper can choose, depending on the kind of bird, the habitat, etc. However there are a few general rules, which must be obeyed. Convert only healthy birds. Convert the birds individually or per couple, never in a group. Watch the constitution of the droppings. Young birds and birds having been fed with a varied diet will adapt more easily. Freshly bought birds must first get accustomed to their new cage and surroundings. 2.1 The Portions Method: The portions method is fast and safe for the conversion of all healthy birds, especially in the case of larger species. The pellets are mixed with the current diet. The total quantity of food is limited to the normal daily ration. The percentage of pellets will be gradually increased. 2.2 The Combination Method: This method is very suitable to safely convert smaller bird species in a period of 5 to 6 weeks, but is also useful for all birds with converting difficulties. Because smaller species eat only a few grams per day, it is practically impossible to weight out an exact portion for 1 day. This method gives a solution by feeding a portion for 2 or 3 days. Full up a box with a quantity of seed/pellet mix for about 1 month. This mixing box is replenished with pure pellets after each feeding. 2.3 The Free Choice Method: The free choice method is the simplest, yet it takes the longest time. Can be used during the breeding season. 3. A few practical examples. From tests in practical conditions we can draw some important conclusions. There is a great individual difference in the conversion time between different species and between the birds of the same species. It is very possible to convert a parrot within 14 days. This is also possible for smaller birds, but not recommendable, considering the loss of condition. 4. Supplementary tips for a smooth food conversion If you intend to use sweetening agents to make the conversion easier, first accustom the bird to the taste before using them on the pellets. Install an eating tray filled with pellets close to their favourite sitting place. Use new or uncomfortable eating dishes for the seed mix; use the old familiar or shallow dish for the pellets. Offer the pellets throughout the day and the seed mix only for a few hours. Room birds can be made jealous by showing them that you enjoy the pellets. At the weaning age, young birds will gladly eat the pellets to satisfy their hunger in an easy way (no peeling). It’s good to set an example by a bird, which already eats pellets. Experience has taught us that the use of one of the suggested tips can be sufficient to help conversion to a good end.


Perneel Zwart Prof. Dr. 1
1 B.v.d. Weyerstraat, 3981 EK Bunnik, The Netherlands

Due to the larger number of species-specific adaptations and specialisation, the feeding of reptiles in zoos is a difficult task. We recognise Herbivorous -, Omnivorous -, Insectivorous -, and Carnivorous reptiles. Water supply needs special attention. The main problems are: providing adequate energy, calcium, vitamin A, and iodine. Piscivorous animals may suffer from thiamin deficiency. Energy provision needs attention and should be related to the physiological status of an animal. Calcium is a key element in the feeding of reptiles. In many reptiles calcium supplementation is a major problem. In the food, the ratio of Ca: P is of importance. Deficiency in calcium leads to a variety of problems such as: insufficient calcification of the skeleton; osteodystrophia fibrosa; osteoporosis; insufficient transfer of calcium to the eggs and the embryo. A drain of calcium occurs in species, which produce extraordinary large clutches of eggs. Prevention and therapy are in providing sufficient food of good quality, containing 1 % calcium and a Ca: P - Ratio of 1,2: 1. Vitamin D3 deficiency: Signs of rickets occur incidentally in young insectivorous lizards. Prevention is by adding 10.000 IU Vitamin D3 aquosum + 4 g Calcium lactate per litre water. Hypervitaminosis D3 leads to calcification of soft tissues. There is no known therapy. Vitamin A deficiency occurs when plain meat is fed. Dosing vitamin A is highly effective. Hypervitaminosis A occurs in tortoises such as the Hermann’s tortoise when dosing 100.000 IU vitamin A or more per kg BW. For therapy food containing Vitamin A or carotene should be avoided. Vitamin B1 deficiency occurs when raw fish meat containing thiaminase is fed. Prevention: heating 5 min. at 80°C or in providing fish free of thiaminase. Vitamin C deficiency occurs in snakes after non-eating during 6 - 12 months.


P. Hajkova MVDr1 and Zdenek Knotek MVDr1
1 University of Veterinary and Pharmaceutical Sciences Brno, Faculty of Veterinary Medicine, Small Animal Clinic, Exotic Animal Division, Palackeho 1-3, 61242 Brno, Czech Republic

A persistent problem in zoo animal nutrition is calcium metabolism. We face almost daily cases of metabolic bone diseases caused by unbalanced mineral-vitamin intake and environmental factors. In this report a clinical case of fibrous osteodystrophy in a green iguana (Iguana iguana) and its treatment with calcitonin is described. A two-year-old female green iguana was presented after the onset of locomotor difficulties, anorexia and intermittent finger twitching. The clinical examination revealed swelling of both femurs and right radius, and renomegaly. X-ray revealed decreased bone density, normal bone marrow cavity along with greatly increased cortical widening of the long bones, as well as early yolk balls. At the time of first biochemistry examination the animal was not hypocalcemic, however, the Ca:P ratio was inversed (Ca - 2.8 mmol/l: P - 2.82 mmol/l). The treatment was started with an oral calcium and vitamin D supplementation. We used a complex vitamin and mineral product for reptiles (Vitamix Rep®, Biofaktory Praha, s.r.o., CR). Oral calcium (Calcium-Slovakofarma®, Slovakofarma, Hlohovec, SR) and vitamin AD3 drops (Combinal AD3®, Galena s.p., Opava, CR) was added. One month later, when the Ca:P ratio had improved (Ca -2.8 mmol/l: P -1.63 mmol/l), the vitamin D product was withheld and calcitonin therapy was initiated. Calcitonin (Miacalcic®, Sandoz) in the dose of 50 U.I. pro toto (1,5 kg BW) was given five times in one-week intervals. During this period the patient still received extra oral calcium and the treatment was done under an UV light source. The treatment resulted in an alleviation of clinical symptoms accompanying this metabolic disease. The Ca:P ratio (Ca - 2.7 mmol/l: P - 1.79 mmol/l) was corrected and no signs of metastatic calcification were noted. This is to document our positive experience with salmon calcitonin, which has not yet been widely used for reptile treatment in Europe. We therefore wish to help zoo nutritionists and Zoo veterinarians to understand the processes underlying the clinical symptoms.


Edward M. Spevak1 and Ellen S. Dierenfeld PhD2
Departments of 1 Mammalogy and 2 Nutrition, Wildlife Conservation Society,
Bronx, NY 10460-1099, USA

Invertebrates comprise the majority of animal life on this planet (95 to 99% of all recognized species), and have been exhibited in zoos for more than 100 years. Despite their diversity and recognized global importance, invertebrates have traditionally been a relatively neglected group in most zoo collections. However, butterflies and insects are becoming increasingly popular and important exhibit species emphasized not only in zoos, but also botanical gardens, museums, stand-alone facilities, education programs, popular press, and for conservation efforts. This paper will examine the role of nutrition in the exhibition, maintenance, and conservation of terrestrial invertebrates commonly displayed in captivity. The determination of feeding requirements for invertebrates in captivity, and successful methods for meeting them, is based on knowledge of the animal’s natural history, mouthparts, and gut structure. While artificial diets have been used for decades for mass rearing of insects required in the study of physiology, ecology, genetics, and developing insect control techniques, targeted development of artificial diets for exhibit species or those species in conservation programs has rarely been investigated. Furthermore, studies of interactions of feeding regimes (amounts and frequencies) with environmental factors necessary for proper growth and development have only been sporadically documented for the species of interest. “Natural diets” are thus most commonly employed for captive populations. Invertebrate (especially arthropod) diets encompass a wide assortment of ingredients including plants, blood, carrion, wood, seeds, nectar, pollen, and other invertebrates. Feeding strategies can be divided into five major categories, with examples and nutrient considerations from each to be highlighted: 1) solid carnivory (mantids, dragonflies, scorpions, and burying beetles), 2) liquid carnivory (spiders and assassin bugs), 3) omnivory (cockroaches), 4) solid herbivory (stick insects, caterpillars, grasshoppers, and snails), and 5) liquid herbivory (aphids and butterflies).