During a visit to our local veterinary, I overhead the vet tell a tortoise owner that they should limit feeding vegetables. He mentioned something called goitrogens in vegetables that is harmful to tortoises. Later I did the research below to find out if the cucumber is safe for tortoises.
Can tortoises eat radishes?
Tortoises should eat radishes leaves moderately since they contain glucosinolates which in large amounts can affect thyroid function, and cause kidney and liver damage. Radish roots have way high levels of glucosinolates and carbohydrates therefore tortoises should not eat them at all.
Vegetables that are high in oxalates, phytic acid, and goitrogen plus glucosinolates should be fed in sparingly.
These compounds affect the health of the tortoise negatively, oxalates and phytic acid affect the absorption of calcium while goitrogens and glucosinolates affect the thyroid function, liver and kidney function.
The main component of the tortoise diet should be fiber, the tortoise can source most of the nutrients they need through microbial fermentation of the fiber. Limit proteins as they can cause accelerated growth which has been associated with shell deformities.
Overall veggies should be part of a balanced diet rather than a staple diet.
Can tortoises eat Radish?
The tables below show different species of tortoises and their preferred diet.
|Rainforest Tortoise Species
|Red-Footed tortoise (Chelonoidis [Geochelone] carbonaria)
|Feed 70% weeds flowering plants and other greens.
|Yellow Footed tortoise
|30% Fruits, and small amount of animal proteins
|Elongated tortoises (Indotestudo elongata).
The rainforest tortoise can eat radishes but when only fed in moderation.
|Greek Tortoises, Spur Thighed (Testudo Graeca)
|100% variety of weeds and flowering plants
|Hermanns tortoise (Testudo Hermanni)
|Limit or avoid: Fruits, vegetables, and salads
|Marginated Tortoise (Testudo Marginata) and the
|Russian / Horsefield (Testudo Horsefieldi)
|Egyptian Tortoise (Testudo kleinmanni)
Mediterranean tortoises can also eat radishes again when fed sparingly, make sure to mix radishes with other veggies.
|African Sulcata Tortoises
|70% mixed grass and Hay
|20-30% flowering plants, succulents and weeds.
|Limit or Avoid: Fruits, vegetables, and salads
Grazing tortoise can also eat radish but they should also be fed in moderation.
Nutritional Value of Radishes
The table below shows the nutritional value of 100 grams of radishes.
Benefits of feeding Radishes to a tortoise
Keeping your pet tortoise hydrated is very important in keeping it healthy, most people believe that since tortoise comes from a water-scarce environment that they do not need water.
As a matter of fact, tortoise needs clean and fresh water every day, read more about how to keep your tortoise hydrated and identify signs of dehydration in tortoise by clicking here.
One of the ways that can contribute to keeping your tortoise is by feeding food that is high in water content. However, this should only be a secondary consideration when choosing feeds for your tortoise.
The first consideration should always be the nutrients content of the feeds, not the water content, veggies such as lettuce have high water content but little nutritional content.
Protein, fat and fiber
One of the most important factors to consider when choosing feeds for your tortoise is the fiber content of the food. Though radishes are not highly packed with these nutrients, when combined with other veggies as part of a balanced diet they can can help.
Being herbivorous makes tortoise depend highly on the fiber of the food they eat, tortoise utilize fermentation form of digestion.
They derive their energy from carbohydrates that are derived from fiber, making fiber a crucial part of the diet.
About 10% to 40% of a tortoise dry matter should be made of fiber, with optimal percentage being 18% to 28%.
Other nutrients such as proteins and fats should be in small amounts in the tortoise diets, they also act as an alternative source of energy.
Fat will help in the absorption of fat-soluble vitamins such as vitamins A and K. Fats should make about 10 % or less while proteins should be limited to 15% to35%.
Too much protein will lead to accelerated growth that has been associated with shell deformities, therefore limit the level of proteins you feed your tortoise.
Tortoise just like other shelled animals needs minerals especially when they are young to build and maintain their shells.
Two of the most important minerals are calcium and phosphorus, they are needed in considerably high levels in young torts.
However, these two minerals affect each other negatively, when phosphorus concentration in the feeds is higher than calcium, it will impede calcium absorption.
Another factor that affects calcium absorption is its availability in the feeds and the body’s calcium requirements.
Therefore, for tortoise staple feeds they should have a higher calcium to phosphorus ratio, with the recommendation being 2:1 or 1:1 respectively.
Radishes have a 1:1 calcium to phosphorus ratio, making them a safe veggie to feed your tortoise, but due to glucosinolates, they should be fed sparingly.
Importance of calcium in tortoise include
- Promotes shell and skeletal structure formation
- Promotes acid-base balance
- Controls heartbeat
- Promotes enzyme action
- Promotes energy transmission
Importance of phosphorus
- Controls chemical reactions
- Controls transfer of hereditary materials
- Utilization of energy
- Promotes skeletal growth
- Promotes kidney health and transfer of nerve impulses
Deficiencies of calcium can have life-threatening health implications such as metabolic bone disease (MBD). Most commonly seen in young or juvenile tortoise that is fed an imbalanced diet.
Therefore, feeding your tortoise a balanced diet that has all the nutrients that it needs is very important in its growth and development.
Radishes also contain other minerals that are needed in small amounts by all tortoises.
Like minerals, tortoises also need vitamins in their diet to lead a healthy life. Vitamins are divided into two categories namely, water-soluble and fat-soluble.
Fat soluble vitamins
Fat-soluble vitamins need fats to be absorbed in the body, the disadvantage of these vitamins is the fact that they can be absorbed in excess and cause health issues such as vitamin toxicity.
For instance when absorbed in excess, when absorbed in excess it can cause vitamin A toxicity.
However, for a tortoise that is fed a balanced diet, such health issues are rare. Vitamin A is very important in the health of a tortoise and facilitates the following functions.
- Promotes the health of the skin and mucous membrane
- Promotes vision health
- promotes reproductive health
Vitamin K is also a fat soluble that helps in blood coagulation and is found in plenty in radishes.
Water soluble vitamins
Water-soluble vitamins are represented by vitamin B complex. These are a group of vitamins that are required in small quantities but are very important in the health of a tortoise.
The table below shows these vitamins and their benefits to tortoises.
|Vitamin B3, niacin,
|also crucial to the energy metabolism
|Vitamin B6, pyridoxine
|involved in energy conversion from glycogen and in the synthesis of hemoglobin and antibodies
How to feed Radishes to a tortoise
- The first step is to feed organically grown radishes
- Do not feed the radishes roots
- Clean the radishes leaves and stem
- Mix it with other veggies to make a balanced diet
- Make sure to remove any uneaten veggies at the end of the day
Risks of overfeeding radishes to tortoises
Despite having the right calcium to phosphorus ratio close to 1:1. Radishes have certain compounds known as glucosinolates. When in excess glucosinolates affects the thyroid glands and inhibit the absorption of iodine.
These compounds also affect the function of kidney and liver and in prolonged exposure, they can cause life-threatening health implications.
Therefore, radishes should not be fed regularly, they should only be fed once in a while and when mixed with other veggies to make up a balanced diet.
Can Russian tortoises eat radishes?
Russian tortoises should eat radish sparingly due to the high levels of glucosinolates that can cause damage to the thyroid gland, kidney, and liver when eaten excessively. However, avoid feeding radish root to the Russian tortoises since the glucosinolates in the radish root is high compared to radish leaves.
Can desert tortoises eat radishes? Yes, the desert tortoise can also eat radishes but only when fed in moderation and as part of a balanced diet. Radishes contain glucosinolates that can affect the thyroid, kidney, and liver function when in excess.
Can you feed tortoise radishes every day? No, you should not feed radishes to tortoises every day since their glucosinolates content can accumulate and affect thyroid, kidney, and liver damage.
While radishes are safe to feed to tortoises in small amounts and less frequently. Feeding them as a staple diet can lead to life threatening implications in the long run.
Remember to mix radishes with other veggies probably those that should not be fed regularly or those that can be fed as staple food.
Avoid radishes roots altogether as they contain lots of glucusinolates which as stated above causes thyroid, liver and kidney damage.