When formulating a diet for an animal, it is important that vegetables are used that meet the needs of the animal. The definition of vegetables is: 'all edible parts of plants that are not fruits or seeds'. This broad definition ensures that vegetables have very diverse nutritional values. Vegetables can be divided into four categories: leafy vegetables, root vegetables, fruit vegetables and other vegetables. The last two categories are occasionally also grouped together as watery vegetables. Table 1 shows examples of the four categories with associated vegetables. The nutritional differences per category are explained below, supported by various bar charts from table 2. Table 1. Different vegetables divided over four categories Leafy vegetables Leaves are the parts of plants where most photosynthesis takes place. As a result, these are the parts of the plant that often contain the most nutrients. For example, leafy vegetables are often rich in vitamins and minerals. In addition, leafy vegetables are one of the few natural sources of folic acid (vitamin B11), which is important for the production of red blood cells and the proper functioning of the nerves. Leafy greens are low in available carbohydrates but relatively high in protein, fat and fibre. Table 2 shows the nutritional values of some leafy vegetables. Root vegetables Based on their properties, root vegetables can be divided into true roots or modified stems. Sweet potato, carrots and cassava are examples of true roots. While potatoes, radishes and beets are examples of modified stems. Root vegetables mainly grow below soil and function as a storage space for starch. As a result, they often also contain a high content of fibre and available carbohydrates, which mainly consist of starches instead of sugars. On the other hand, the amount of water is also on the lower side. Table 2 shows the nutritional values of some root vegetables. Fruit vegetables Fruit vegetables include tomatoes, bell peppers and cucumbers. These are all characterized by having a fleshy and seed-rich texture. Fruit vegetables are relatively low in protein, fat, fibre, available carbohydrates and minerals. However, they contain a relatively high amount of water and vitamins. The available carbohydrates in fruit vegetables mainly consist of sugars and hardly any starch, which means that the total amount of sugar is also relatively high. Table 2 shows the nutritional values ​​of some fruit vegetables. Other vegetables As the name suggests, the other vegetables category is suitable for vegetables that are more difficult to place in one of the other three categories. Because this category is quite diverse, it is more difficult to make general statements. A remarkable feature of many of these vegetables is that they mainly consist of a stem. These vegetables also often contain a higher content of proteins, fibers and vitamins. On the other hand, the amount of available carbohydrates is often lower. Table 2 shows the nutritional values ​​of some vegetables within this category. *Graphs are based on the average values of the different categories in table 2* Table 2. Nutritional composition of different vegetables divided over four categories Source: Food composition and nutrition tables, Souci, Fachmann and Kraut, 7th revised and completed edition

We have two different variants of tortoise diets from Mazuri in our assortment. Tortoise diet is the most well-known variant, a very popular product for tortoises. In addition two this diet we do have a a new variant: Tortoise diet LS. But what is the difference? In short, compared to Tortoise diet LS, the "normal" Tortoise diet contains less starch and a higher fiber content. LS therefore stands for Low Starch. This makes it more suitable for true herbivorous tortoises, whereas 'normal' Tortoise diet is also recommended for more omnivorous species. Below is a summary of which foods are recommended for which species. Tortoise diet: Burmese or Indian Star Tortoise, Elongated Tortoise, Red-footed Tortoise, Adult Box Turtles and Wood Turtles. Tortoise diet LS: Aldabra, African Spurred/Sulcata, Desert, Egyptian, Galapagos, Gopher, Greek, Leopard, Pancake and Radiated tortoise. More information can be found on the data sheet:

Vegetable material is relatively difficult to digest due to the presence of fiber-rich cell walls. Due to these cell walls, chewing and digesting plant material takes more energy. To break down these cell walls and release energy, herbivores depend on certain bacteria during the fermentation process. In addition, the nutritional value of plant material is much lower than that of animal products, so that the food intake of many herbivores is higher than that of carnivores and omnivores. Differences between browse and grasses There are major differences between the plant material eaten by herbivores. The main differences are between the categories: grasses and browse (see table). First of all, grasses consist of thicker, slow-digesting fibers (cellulose) and weeds consist of thin, fast-digesting fibers. In contrast, browse often contains more indigestible fibers of lignin. The thickness and amount of indigestible fibers depend on the season, so that the nutritional value of browse fluctuates more strongly. In contrast, grasses are more stable throughout the year. Secondly, there is a difference between the protection mechanisms of grasses and browse. For example, grasses have more silica, which causes teeth to wear off; and browse more tannins, which reduce digestibility. Thirdly, there is a difference between the way of growing, which makes grasses a more stable form of food for large herbivores, while browse brings more diversity in the diet. Source: (Shipley, 1999) Classification of browsers and grazers Different herbivores use different plant parts. According to Hofmann and Stewart (1972) there are three groups: 1) Grazers, where <25% of the diet is browse; 2) Browsers, where >75% is browse; or 3) Intermediates, who select both grasses and browse. Eating different plant parts allows many different species of herbivores to live in the same place without directly competing with each other for food. According to Hofmann (1989), herbivores can be classified as 25% grazers, 40% browsers, and 35% intermediates. The table below shows an example of such a layout. In which group an animal is classified is partly on a subjective basis and therefore not black and white. Source: (Hofmann, 1989) Difference in digestion between browsers and grazers The digestive systems of browsers and grazers are specialized to digest the food from their preferred diet as well as possible. Grazers benefit from teeth with a high crown, short roots and extra enamel due to rapid tooth wear from fibrous and silica-rich material. In contrast, browsers have shorter crowns and longer tooth roots. The shape of the muzzle also differs between the two; grazers often have a larger snout so that more material can be eaten, but this means that they are less able to graze selectively. Browsers have a narrower snout, longer tongue and relatively larger mouth opening. With this, food can be properly selected by, for example, stripping leaves from a branch. Management In order to provide all herbivores with a good diet, it is important to know which category they belong to. In general, fruit is not recommended and a salt stone is recommended. Furthermore, grazers can be fed with different types of hay and possibly a small amount of browse. Browsers can be fed with different browser variants and additionally with some roughage (such as alfalfa). Intermediates can be fed with both hays and browses, with a ratio of 50:50 recommended. Both hay types and browse varieties can be fed dry and fresh in combination.

Kiezebrink is the official exclusive European importer of the South African game feed ‘Boskos’. Literally translated Boskos means; ‘feed from the bush’. It is a pelletised diet made of shredded and dried bushes, such as Acacia species of the African Savannah. Zookeepers have found that herbivores in captivity instinctively appear to recognise Boskos for what it is, a foodstuff that is natural to them. Boskos is a staple diet, especially as a winter grazing supplement, in zoos, national parks and game reserves around the world. More European zoos are feeding Boskos, as this natural food is healthier for their animals. For our customers, we made a video of the process of making Boskos. The Boskos movie from Wes Enterprises:

We commissioned a study to analyse the particle size of Boskos Browser pellets. You can access the result via the link below:

Variety feeding To feed the necessary nutrients, it is recommended to ensure variety in the diet of animals. Different components in the menu contribute to the animal's nutritional needs. This way, the menu contains enough protein, fat, fibre and other (micro)nutrients in total. It is a misconception that this variety has to be offered every day. In fact, if a menu with a lot of variety is offered daily, this can actually end up making the diet poorer. Many animals are naturally selective, so they will select and eat a few items from this wide range. They may leave the rest, or when animals are housed in groups, the same items are always left behind for the animals that are lower in rank or reach the feeding bowl later. To avoid this, the method of ‘forced variety’ can be applied. This means that the diet still contains the necessary variation but this variation is spread throughout the week. So during each feeding moment, only one product is offered, making selection impossible. The images below, provided by Ben Lamberigts of Wisbroek, show clear examples of what such a menu looks like when it is offered mixed or per product for five feeding moments.

In the wild, tarantulas often eat large insects or small reptiles. So they are quite capable of digesting animal food. In principle, day-old chicks could also be suitable for this purpose. However, feeding day-old chicks to a tarantula may involve risks. These risks are related to pesticides that can be used in the laying poultry sector. A common parasite in this sector is the bird mite, also known as blood lice. Blood lice are a danger to humans and animals because they can transmit diseases but can also lead to weakening of the animal. To control blood lice, pesticides containing permethrin as an active ingredient can be used in the laying hen industry. Permethrin affects the parasite's nervous system, causing the parasite to die. Mites, like ticks, belong to the class of arachnids. They are thus related to the spider and have a similar body structure. This means that the nervous system of the (bird) spider is also affected when it comes into contact with permethrin. Our day-old chicks come from different hatcheries. The hatcheries themselves usually do not use blood lice control. However, it cannot be guaranteed that the hens have never been treated with it. Especially the first eggs laid by a mother animal may therefore contain a small dose of permethrin. In this way, it is therefore also possible that the first chicks may have a small dose of permethrin in them. For the chicks, this poses no danger, but for a tarantula that subsequently eats the chicks, it can pose a great risk. We therefore strongly advise against feeding day-old chicks to your tarantula.

Plants contain many different substances. For instance, flavonoids, carotenoids and antioxidants are some of the substances commonly found in plants. These substances are also known as phytochemicals. Some substances in plants can have a negative effect on the body in excess. These substances are also called phytotoxins. One of the most common phytotoxins are goitrogens. Goitrogens can have a negative effect on the animal because it can block the passage of iodine to the thyroid gland. Ultimately, this can lead to the development of various conditions such as a goiter, shedding problems, growth retardation or lethargy. There are three different types of goitrogens: goitrin, thiocyanates, and flavonoids. When plant stocks are destroyed by, for example, chewing or cutting, the substances goitrin and thiocyanates are formed. Flavonoids, on the other hand, are already naturally present in plant stocks. Some of these substances are good antioxidants, but there are also flavonoids that can be converted to goitrogenic compounds by intestinal bacteria. In small amounts, goitrogens are not harmful to the animal. However, care must be taken not to feed too many plant stocks high in goitrogens. There are a number of plant stocks that are high in goitrogens such as: spinach, cassava, peanuts, soybeans, kale, broccoli, Brussels sprouts, cabbage, canola, cauliflower, radishes, and rapeseed. It is advised to feed herbivorous animals a variety of vegetables to avoid excess goitrogens. In addition, supplementing iodine is not recommended because animals are sensitive to an excess of iodine.

Insoluble grit In the wild, herbivorous birds mainly eat plant-like material and/or seeds. To be able to digest this, the seed hulls and plant cell walls must first be destroyed in the gizzard. Naturally, birds often consume small non-digestible pebbles for this. As an alternative to these stones, insoluble grit is fed . In captivity, birds are mainly fed easily digestible pellets instead of plant-like material and/or seeds. As a result, these birds have little or no need for insoluble grit. In addition, birds can also take in stones themselves if they are (partially) kept outside. For birds in captivity that do eat a lot of plant-like material and/or seeds, it is recommended to add insoluble grit. Soluble grit Birds that are fed pellets are generally provided with sufficient minerals such as calcium. However, there are a number of birds that have an extra need for calcium, such as growing birds and laying birds. In these situations, soluble grit is often supplemented. Special pellet diets with a higher percentage of calcium are also available for these birds. Research has shown that birds have the capacity to self-regulate their calcium intake. So they will not quickly absorb an excess of calcium. It is therefore recommended that a small percentage of the diet consists of soluble grit. This is also part of the diet of many birds in the wild. There are different types of soluble grit such as sepia, oyster shell, limestone (calcium carbonate), marble (crystalline limestone) and gypsum (calcium sulfate).

Hibernation is a state of minimal (metabolic) activity. When an animal is in a state of hibernation during the summer, it is called aestivation or summer sleep. In the past, the concept of hibernation was based on an absolute drop in body temperature (often more than 32°C). Today, this is based on the decline in metabolism. During hibernation, various processes in the body slow down: body temperature, metabolism, respiratory rhythm and heart rhythm. The benefit of hibernation is that an animal can survive during periods of food scarcity (such as winter) without having to spend a lot of energy gathering food. During hibernation, body fat is mainly used as an energy source. This fat is stored during the active period of the year. In addition, some animal species (such as the arctic ground squirrel) can recycle nutrients in the body. Research has shown that this species can break down its muscle fibers during hibernation, thereby releasing nitrogen. This nitrogen can be converted into amino acids and then into proteins, which keeps body tissue intact ( source ). The length of hibernation depends on the species, ranging from a few days to many months. Some animals sleep during the entire hibernation, while others sleep for broken periods. This is due to the different types of hibernation: Mandatory hibernation These are animals that are in hibernation at fixed times every year, regardless of the ambient temperature and amount of food. These species undergo a 'traditional' hibernation: a body state in which the body temperature drops sharply along with the breathing and heart rhythm. Species that fall into this group include: reptiles, amphibians, bats, hedgehogs, (many) rodents and some insectivores. Optional hibernation These are animals that are only in hibernation due to environmental stressors, such as temperature, food shortage or both. Species within this group undergo both 'traditional' and 'untraditional' hibernation, depending on their body temperature or metabolic activity. Species that belong to this group are: some monkeys (e.g. dwarf lemurs), prairie dogs and bears. Bears are wrongly thought to be a 'traditional' hibernation even though this concerns a winter rest; the heart rate does slow down, but the body temperature remains fairly constant. A bear can therefore easily be woken up. Hibernation in captivity It is not favourable for a zoo to have no visible animals for a long period of the year. However in captivity, true hibernation is rare for animals. Often the duration of the hibernation is then greatly reduced from a few months to only a few weeks. As a result, an animal's diet can also deviate from its natural diet. To compensate for this, zoos often have a special 'bulk' program in the months before natural hibernation. This allows the animals to store energy reserves in the body to be consumed during these shortened hibernation periods. In addition, more and more seasonal diets are being used to imitate the natural variation in the diet. In 2021, Marcus Clauss gave a presentation ( link ) on the work of Charles Robbins discussing the concept of seasonal diets. To summarize, both the diet composition and amount can be adjusted to mimic different seasons. Two examples of this can be seen in the charts below for different bear species. By feeding this way, it simulates the availability of food throughout the year. Source: ( link ) A practical example of this is a study from the San Diego Zoo ( link ). Here, the goal was to feed bears more seasonal diets to better mimic seasonal physiological changes. After a year, the bears showed twice as much weight variation, which is more in line with natural variation. Source: ( link ) Although this concept is emerging, it is even more important to look at the individual animal. Always adjust the diet and feeding frequency to the individual. In addition, the charts above are just examples and the ideal diet depends on the species and individual.