by Jyothsna Nelloolichalil, International petfood magazine, UK

Zoos play a key role in conservation of animals as much as it does in education and creating awareness. Animal welfare is of utmost important in recent times considering the loss of biodiversity. The success of breeding programmes as well as the health and welfare of the animals depend on supplying the proper nutrition for the several diverse species we care for. A zoo is a shelter for numerous animals with varied nutritional needs and meeting each of them must be ideal when compared to their natural habitat.

History of feeding Zoo animals

Historically, most zoo animal nutrition was based on nutritional requirements of giraffes as they have been the most common zoo animals and this eventually ended up in zoo animals being fed incorrectly, often being given too much grass-based forage as this was most readily available. Many carnivorous animals were fed with cereal based feeds produced for the livestock production and high cereals diets can cause significant digestive issues for them such as acidosis due to rapid rumen fermentation in zoo animals. But, over the last few decades, there has been notable efforts in meeting the nutritional requirements of zoo animals.

How should zoo animals be fed?

The minimum nutrient requirements established by the National Research Council (NRC) for domestic and laboratory animals can be useful starting points in setting target nutrient levels for an exotic zoo species. Although NRC requirements are less directly applicable to other species, they can still serve as a starting point in meeting the correct nutritional requirements for exotic zoo animal.

All food should be of good quality, spoiled or food stored for a longer period (more than one year) must not be fed. Topping off the food bowl daily is also discouraged as the uneaten food in the bottom can get spoiled, hence food and water bowls should be emptied and cleaned every day. Cafeteria style feeding is also discouraged as chances of zoo animals choosing a balanced nutritional diet when offered with different food choices are unlikely.

Feeding should take place in the morning, and additional foods should be provided throughout the day, to enhance intake of pelleted diets. The weight of every diet item to be consumed and the actual consumption should be noted. Fruit, most grains and seeds, most insects, and muscle and organ meat are poor sources of calcium, and excessive eating of these foods can cause a calcium deficiency. Insects should be fed calcium gut-loading diets with at least 12 percent-15 percent calcium. Another option is to dust the die with a calcium-phosphorus powder mixture, although it is unlikely that this will supply enough calcium.

Obesity in zoo animals is common than lack of nutrition. Ungulates, primates, and carnivores can rapidly become overweight when excess amounts of a high-quality diet are offered, particularly when activity is limited. Both adult and growing animals should be routinely weighed to monitor changes. If weighing four times a year is not possible, a body score index should be performed.

Water for exotic and zoo animals:

Water intake should be assessed routinely but especially in animals with compromised renal function, in lizards or birds prone to gout, and in animals under conditions of high temperature or low humidity in which evaporative losses can be expected. The salt content of water should be known, because some species are less tolerant than others. Animals fed dry feeds (pellets, extrusions, hay, etc) require more water than those fed succulent feeds. Potable water should be available ad lib.

While animals in the wild get water from the food they consume, it may not be the case with zoo animals who are fed with low-moisture foods like pellets. Many reptiles, especially tropical ones, may require high levels of humidity to maintained hydrated. Some lizards, who may not be seen drinking from standing water, benefit from daily misting with warm water. Low environmental humidity (or possibly upper respiratory tract disease) may cause eye lesions in semiaquatic turtles (such as box turtles) and some tortoises, rather than vitamin A deficiency.

Nutritional supplements:

The use of nutritional supplements is popular among animal care takers although many keepers provide the animals with nutritionally complete food. If a zoo animal’s diet is lacking in a certain vitamin, a specific supplement in a certain dosage should be suggested. Due to toxicity and nutritional imbalance, excessive supplementation of some nutrients (such as some fatsoluble vitamins, selenium, and copper) can be just as hazardous as inadequate dosage. Micronutrient supplements may be necessary for diets high in grain products and cultivated fruits and vegetables, but they come in a wide range of compositions.