By Rick Kleyn
There are many species of turtles and tortoises, each of which may have different nutritional and housing requirements. In addition, in South Africa, there are restrictions on keeping certain species in captivity. It is therefore important that we carefully identify the species that we are dealing with in order to be sure that what we are doing is both legal and sound in terms of management and nutrition.
Tortoises and turtles are wild animals living in captivity. Very little research has been conducted into the nutrient and feeding requirements of individual species. This means that in order to successfully feed these specialized reptiles we need to rely on the nutritional knowledge built up from other species (comparative nutrition) as well as to mimic their natural diet and living conditions as close to their natural environment as we can.
The first thing that needs to be established about a turtle or tortoise is whether or not they are an herbivorous, an omnivorous, or a carnivorous. Feeding meat to a vegetarian tortoise is as unnatural and unhealthy, as feeding steak and chicken to a cow. At the same time, feeding fruits and alfalfa to a carnivorous aquatic turtle is like trying to raise a cat on salad and vegetables. In the table below, a broad outline of the different classes of animal are shown.
Turtles and tortoises are particularly prone to vitamin and mineral deficiencies. They are especially sensitive to deficiencies in the fat soluble vitamins A and D as well as to Calcium and Phosphorus. It is therefore essential that all diets be supplemented with these essential nutrients. Remember though, that Vitamin A in particular is highly toxic when fed at excessive levels, so feed only according to the suppliers recommendation. As a rule, do not use more than one supplement as using a number of different products is the quickest way to run into the danger area with Vitamin A.
Turtles can be fed live food such as small fish, pinkies or worms. However they stand the risk of picking up any of the parasites or other diseases that they prey animals may have had. Avoid feeding “flesh” only diets as this can aggravate calcium and phosphorus deficiencies. There are some good commercial diets available using them makes sense as they are well balanced. The concern with these is that the turtles usually need to be started on them when they are young to ensure that they will eat them. Adult turtles need to be fed two or three times a week, while young, fast growing animals should be fed daily. Do not overfeed as they will become obese and foul the water.
Tortoises are ancient animals that are thought to have evolved 50 mil years ago. They can survive in harsh, dry climatic conditions. In the wild, they consume large amounts of fiber including flower blossoms and succulents. It is believed that their total protein requirement is less that 10%. In captivity you can feed these items but you can also feed lucerne hay, fruits and vegetables. Never feed a tortoise iceberg lettuce as they contain mostly water and hardly any nutrients. It is not recommended that you feed more than 10% of the diet as fruit. Small amounts of dog food (no more that 5% of the diet) can be soaked in water and offered. Complete tortoise diets are available and are a viable option. All tortoises need large amounts of calcium and phosphorus in their diets as these minerals form an integral part of the shell. For this reason all fruit and vegetables should be dusted with a mineral supplement. You can feed to them some crushed eggshell once a week so as to boost the calcium level of the diet.
Avi-Products manufacture Avi-Sup (Twin Pack) vitamin and mineral supplement for birds. The recommended feeding rate is to add two teaspoons full (of both the vitamin and mineral and trace elements) per kilogram of food. This level would be adequate for turtles, but is would be a good idea to increase the mineral and trace element supplement to 3 or 4 teaspoons per kg of food for tortoises.
Nutrition is one of the most important aspects in maintaining a healthy and happy turtle or tortoise. By using common sense and by following these simple guidelines, you can provide an excellent diet for your turtle or tortoise.