Looking to deepen your expertise in animal nutrition? Our Knowledge Base offers practical insights, research findings, and feeding advice—covering everything from digestive systems and diet composition to enrichment strategies and sustainability.
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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
Raw meat and prey animals contain natural bacteria. For healthy animals these bacteria are harmless. For people, especially young children, elderly and people with a weakened immune system, the bacteria can cause problems. Therefore it is important that raw food products are handled in the right way.
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.
Most people know that variation in an animal’s diet is important. But what does variation mean and why is it so important? The right variation With Kiezebrink’s BARF products and their minced meat mixtures variation is necessary to form a balanced diet. This is because these products on its own are not considered to be a complete diet. This means they must be varied to form a balanced diet. There are four categories of meat: white meat, red meat, game meat and fish. During the week when at least one sort of each meat category is fed, then it can be assumed that a balanced diet is fed. In the following overview the sorts of meat in each category is illustrated. Red meat BeefLambHorseDuck White meat ChickenTurkeyQuailRabbit Game HarePheasantPigeon Fish SalmonFat fish Why variation? Dogs and cats are in need of all kinds of nutrients. When only one sort of meat is fed, it’s likely that certain nutrients will be lacking in their diet. This is because different categories of meat have differing nutritional values. Fish for example contains a high percentage of omega 3 fatty acids and selenium. Red meat contains high levels of vitamin B12, while white meat contains more vitamins B3 and B6. Also, the structures of the protein in meat (the amino acids) vary by the type of meat. Therefore it’s important to feed all the different categories of meat, to make sure the dog or cat receives a wide range of nutrients. BARF diet? When feeding the BARF products from Kiezebrink it is not only important to vary with different types of meat but to also include muscle meats, organs and meaty bones. More information about this can be found via this link .
We use animal by-products for our raw food products. These raw materials consist of all kinds of parts such as organ meats, backs and necks. With some raw materials there is a risk that the thyroid gland is still present, such as necks and throats. The risk of this is that thyroid hormone may still be present in the tissue of the thyroid gland, which can cause health problems in dogs and cats. To make sure that these raw materials do not contain (remnants of) thyroid tissue, we have them analyzed for iodine content. The thyroid hormones T3 and T4 consist mainly of iodine. If the amount of iodine in the diet is low, there may not be much T4 in it. These analyzes showed that throats contain a high iodine content, which is why we do not use them. Other raw materials such as chicken necks and duck necks contain little iodine (less than 0.1 mg/kg), so these are used in a number of products.
Kiezebrink specializes in raw food for dogs and cats, we have a very wide range available. For these products, animal raw materials from various categories are used, such as white meat, red meat, fish and game. By feeding products from all these categories, a varied and balanced menu can be put together. Game The game category includes products such as deer, pheasant, hare and pigeon. These animals were shot in the wild, unlike any other species we sell that are bred in captivity and killed with CO2 or some other method. Because these animals have lived in the wild, the composition of the meat is also different, game meat contains more omega 3 fatty acids and is a very good addition to the menu of the dog or cat. However, there are also disadvantages to game meat, because the animals may have been in contact with contaminated soil and in some countries shooting with lead shot is still allowed. As a result, the meat and organs from wild animals may contain more heavy metals than from animals raised in captivity. Unfortunately, little information is known about the precise absorption of these heavy metals. Because feeding game also has many advantages, we do recommend these products, but no more than once a week. Gerofke et al. (2019), Heavy metals in game meat, Food safety assurance and veterinary public health no. 7. https://www.wageningenacademic.com/doi/epdf/10.3920/978-90-8686-877-3_24 Kral et al. (2015), Evaluation of mercury contamination in dogs using hair analysis, Neuroendocrinology Letters, vol. 36(1). https://www.nel.edu/userfiles/articlesnew/NEL360915A11.pdf Brand et al. (2019), Kennisoverzicht vraagstukken diffuus lood in de bodem, RIVM Rapport 2019-0006. https://www.rivm.nl/bibliotheek/rapporten/2019-0006.pdf Wani et al. (2015), Lead toxicity: a review, Interdisciplinary toxicology, vol. 8(2), https://content.sciendo.com/view/journals/intox/8/2/article-p55.xml Dżugan et al. (2012), Evaluation of heavy metals environmental contamination based on their concentrations in tissues of wild pheasant, Journal of Microbiology, Biotechnology and Food Sciences, Vol. 2 (1), https://www.jmbfs.org/wp-content/uploads/2012/08/jmbfs-Dzugan-B.pdf Valencak (2015), Healthy n-6/n-3 fatty acid composition from five European game meat species remains after cooking, BMC Research Notes vol. 8, (273). https://bmcresnotes.biomedcentral.com/articles/10.1186/s13104-015-1254-1
It has long been known that feeding whole prey animals to felines has a positive effect on gastrointestinal health. A study was recently conducted to find out more about what causes this. For this, a group of cats were fed two different diets: ground mice or whole mice. For the study, the cats were given extruded kibble. To measure different things, urine and faeces were collected. It did not matter in the results whether ground or whole mice were fed. Both diets had a positive effect on intestinal flora. The ratio in fatty acids produced by the gut bacteria was better, and fewer harmful fermentation products were produced. So this study showed a clear positive effect on gut health by feeding both ground and unground mice. Unfortunately, current legislation does not allow feeding mice to domestic cats as it does not fall under category 3a or 3b of animal by-products. Nevertheless, it is likely that this effect also applies to feeding raw food, similar effects have also been seen in other studies. D'Hooghe SM-TJ, Bosch G, Sun M, et al. How important is food structure when cats eat mice? British Journal of Nutrition. 2024;131(3):369-383. doi:10.1017/S0007114523002039
We sell prey animals bred in 3 different ways: 1. SPF farmed prey animals 2. Commercially farmed prey animals 3. Commercially farmed prey animals that have been irradiated Spf farmed prey animals SPF prey animals are animals specifically bred and kept under conditions free of specific pathogens (disease agents). They are farms that maintain optimum breeding standards, such as using sterile breeding rooms, providing sterile food and not using medication. The word ‘SPF’ stands for Specific Pathogen-Free , meaning that these animals are free from certain micro-organisms that can cause diseases. Our SPF mice, rats and hamsters are tested for: Viruses: - Mice: Murine hepatitis virus (MHV), Mouse parvovirus (MPV), Sendai virus, Ectromelia (mousepox), Mouse norovirus (MNV). - Rats: Rat coronavirus (RCV), Kilham rat virus (KRV), Hantavirus, Rat theilovirus (RTV). Bacteria: - Mice and rats: Helicobacter spp, Mycoplasma pulmonis, Salmonella spp, Clostridium piliforme (Tyzzer's disease). Parasites: - Mice and rats: Syphacia spp (pinworms), Myobia musculi (fur mites), Giardia spp. SPF prey animals are often used in scientific research, such as biomedical research. For these studies, it is important to obtain results that are not affected by diseases. The ‘overproduction’ of these SPF bred prey animals are ideally suited for feeding zoo animals, birds of prey and reptiles. Because this type of prey animal does not carry any specific pathogens, the risk of any disease contamination by a prey animal in humans or animals is practically impossible. Our SPF prey animals are bred in Germany, France, the Netherlands and China. Commercially farmed prey animals Our commercially farmed prey animals are bred in farms in and outside the EU. They have less strict rules than an SPF farm applies, but of course the legally required safety standards apply here too. These farms are visited annually by a veterinarian and their animals are tested quarterly for the presence of Salmonella. Irradiated commercially farmed prey animals Irradiated prey animals are treated with ionising radiation to kill any potential pathogens such as bacteria, viruses, parasites and fungi, while largely preserving the nutritional value of the animal. Using irradiated prey animals offers several advantages, especially in environments where the health of the feeding animals or maintaining sterile conditions is crucial. Here are some of the key benefits: 1. Reduced risk of disease transmission : Irradiating prey animals greatly reduces the risk of disease transmission from prey animals to predators or other animals. This is especially important in zoos, breeding programmes, and when keeping exotic animals, such as reptiles. 2. Extended shelf life: Irradiated prey animals often have an extended shelf life because the radiation slows the growth of spoilage micro-organisms. This makes it easier to stock and store food without rapid spoilage. 3. Maintaining nutritional value: Irradiation kills pathogens without significantly affecting the nutritional value of the animal. This means the predators continue to receive necessary nutrients without exposure to harmful bacteria.
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. De Boskos film van Wes Enterprises is hieronder te zien:
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.
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.
Onderzoek DK Dried Browse Mulch 22-03-2024 Introduction Giraffes (Giraffa camelopardalis) are browsers, primarily feeding on leaves from trees and shrubs, with a preference for acacias and other leafy plants4, 9. Foraging is their primary activity, essential for maintaining their bodies. Rumination is also crucial to giraffes' natural behavior, aiding in the effective digestion of food, especially breaking down insoluble carbohydrates like fiber found in plant cell walls3. In captivity, fulfilling giraffes' nutritional needs is challenging, particularly during winter when natural food sources diminish. Limited availability of fresh leaves and branches leads to provision of mainly roughage, alfalfa hay, and low-fiber pellets, which may not adequately stimulate natural behaviors, potentially resulting in abnormal behaviors like oral stereotypies1, 2, 7, 8, 9, 10. Increasing fiber content in the diet can promote natural behaviors, including longer rumination periods and reduced abnormal behaviors3,6. The development of "DK Dried Browse Mulch" by Kiezebrink offers a promising nutritional supplement for giraffes, resembling their natural diet and rich in dietary fiber5. This could potentially increase foraging and rumination time while reducing abnormal behaviors in captive giraffes. Methods & Materials • The research, carried out at Dierenpark Amersfoort in the Netherlands, spanned from December 11th, 2023, to January 14th, 2024, focusing on the behaviour of four male giraffes. • Daily rations based on giraffes weighing 900 kg - Diet 1: 4.4 kg of browser pellets - Diet 2: 4.4 kg of browser pellets + 2 kg of DK Dried Browse mulch. Both rations were divided into two feeding sessions. • For 10 days per diet, instantaneous scan sampling at 30-second intervals during morning feedings monitored foraging behavior. • For 8 days per diet, continuous focal sampling observed rumination and abnormal behaviors after morning feedings for one hour per giraffe per day. • Alfalfa hay, browse, and ad libitum water were available throughout the day. • Linear Mixed Models analyzed the impact of DK Dried Browse mulch on foraging and rumination behavior. • Due to limited data, oral stereotypies are not statistically tested. A simple descriptive statistics is used to compare oral stereotypies before and after adding DK Dried Browse mulch, specifically focused on 'licking unnatural objects'. Results & Discussion • Giraffes spend significantly more time foraging during the morning feeding with Diet 2 compared to Diet 1 (Table 1). The addition of DK Dried Browse mulch to Browser pellets likely increased foraging time (p < 0.05). • Giraffes spend significantly more time ruminating with Diet 2 compared to Diet 1 (Table 1). The addition of DK Dried Browse mulch to Browser pellets likely increased rumination time (p < 0.05). • After the addition of DK Dried Browse mulch to Browser pellets, the duration of licking unnatural objects is halved, suggesting a potential alleviation of oral stereotypies (Figure 1). However, this was not statistically tested. Table 1*: Comparison of Average Duration of Foraging, Rumination, and Oral Stereotypies between Two Diets: Browser Pellets (Diet 1) and Browser Pellets with the Addition of DK Dried Browse Mulch (Diet 2), Highlighting Differences in Foraging and Rumination Times. Figure 1*: Difference in average duration of foraging, rumination and oral stereotypies between Browser pellets (Diet 1) and Browser pellets with an addition of DK Dried Browse mulch (Diet 2) *For this study on the impact of DK Dried Browse mulch on the foraging, rumination, and abnormal behaviors of captive giraffes, we used a base diet comprising Kasper Natural Browser (10mm) and Boskos Browser. • The study provides valuable insights, but factors like limited visibility and sample size could affect interpretation. Changes in mulch quantity and the presence of finely ground acacia fibers in DK Dried Browse mulch could also impact outcomes. Additionally, solely daytime observations may limit comprehensive understanding; nocturnal observations could provide supplementary insights. Conclusion • Supplementing Browser pellets with DK Dried Browse mulch positively affects the duration of foraging, rumination, and abnormal behaviors in giraffes. • Giraffes receiving DK mulch spend significantly more time foraging and rumination while exhibiting reduced abnormal behaviors, particularly in licking unnatural objects. • Further studies are necessary to evaluate the long-term effects of this dietary adjustment and explore other potential factors influencing behavioral changes. References Appleby, M. C., & Lawrence, A. B. (1987). Food restriction as a cause of stereotypic behaviour in tethered gilts. Animal Production 46: 104-110. Bashaw, M. J., Tarou, L. R., Maki, T. S., & Maple, T. L. (2001). A survey assessment of variables related to stereotypy in captive giraffe and okapi. Applied Animal Behaviour Science, 73(3), 235–247. https://doi.org/10.1016/s0168-1591(01)00137-x Baxter, E., & Plowman, A. B. (2001). The Effect of Increasing Dietary Fibre on Feeding, Rumination and Oral Stereotypies in Captive Giraffes (Giraffa Camelopardalis). Animal Welfare, 10(3), 281–290. https://doi.org/10.1017/s0962728600024052 Davis, D. E., Dagg, A. I., & Foster, J. B. (1978). The Giraffe. Its Biology, behavior and ecology. The Journal of Wildlife Management, 42(3), 711. https://doi.org/10.2307/3800862 DK Zoological. (2023). DRIED BROWSE MULCH. Geraadpleegd op 5 december 2023, van https://www.kiezebrink.eu/public/attachments/Droogvoer/DK%20Zoological/DK%20Dried%20Browse%20Mulch.pdf Hummel, J., Clauß, M., Baxter, E., Flach, E., Johanson, K., Fidgett, A., Eulenberger, K., Hatt, J., Hume, I. D., Janssens, G., & Nijboer, J. (2006). The influence of roughage intake on the occurrence of oral disturbances in captive giraffids. In Filander eBooks (pp. 235–252). https://doi.org/10.5167/uzh-3523 Hummel, J., Zimmermann, W., Langenhorst, T., Schleussner, G., Damen, M., & Clauss, M. (2006). Giraffe husbandry and feeding practices in Europe. Results of an EEP survey. In: 6th Congress of the European Association of Zoo and Wildlife Veterinarians, Budapest (Hungary). https://doi.org/10.5167/uzh-3562 Koene, P. (1999). When feeding is just eating. How do farm and zoo animals use their spare time? In D. van der Heide, E. A. Huisman, E. Kanis, J. W. M. Osse, & M. W. A. Verstegen (Reds.), Proceedings 5th Zodiac Symposium Wageningen, The Netherlands (pp. 13-19). Okabe, K., Kawamura, A., Fukuizumi, H., Ishiuchi, K., & Kase, C. (2019). Does oral stereotypy in captive giraffes decrease by feeding them evergreens and barks in winter. Animal Behaviour and Management, 55(4), 165–173. https://doi.org/10.20652/jabm.55.4_165 Terlouw, C. E. M., Lawrence, A. B., & Illius, A. W. (1991) Influences of feeding level and physical restriction on the development of stereotypies in sows. Applied Animal Behaviour Science 28: 135 – 152.
