Nutrition biology

The hamster's nutrition biology

These comments apply both to the golden hamster and the dwarf hamster species. Although from a biological point of view, these popular domestic rodents belong to different species, they can be easily compared and are virtually identical as far as their internal physique and ingestion and utilisation of food are concerned. Their demands on the food are in principle also the same: Apart from high-quality vegetable food, all hamsters also need animal components as they depend on animal protein. Contrary to chinchillas, guinea pigs and rabbits, grains agree quite well with the different hamster species. These are virtually vegetable nutrient concentrates in the form of seeds and hamsters are so-called "concentrate eaters". Our diagram shows the organs involved with digestion. The digestive tract starts with the mouth:

The incisors are sharp, shaped like chisels and are used to cut off chunky food and to open seed coats. They constantly keep growing and have to be permanently worn. Ideally, this is done when the teeth rub against and on each other when the animals bite off and chop up hard compound feed of best quality and crack husks. The incisors are located in the front of the mouth, two each in the centre of the upper and lower jaw. It is very important to maintain their health by correct feeding and by offering rough nesting material the hamsters have to chop up themselves. Particular suited for this purpose are straw, cellulose, coarse hay and small pieces of branch. Also when selecting animals for breeding, strict attention should be paid to dental health so that defective positions are not handed down to the next generation.

Further to the rear of the mouth cavity you will find the molars, which contrary to those of rabbits, guinea pigs and chinchillas have roots and therefore do not constantly grow. The molars crush and grind up the food morsels. Between them, the food is also well salivated so that it slides down easily. The fluid for that is emanated by the salivary glands. First enzymes contained in the saliva, which are also called ferments and are genuine biocatalysts, start with predigestion.

Starting from the mouth cavity and located in front of the pharynx, the so-called cheek pouches branch off to the left and right. They are extremely expandable and flexible and when completely filled, reach between skin and body musculature, i.e. outside the abdominal cavity, almost up to the hind legs! The inside of the cheek pouches is lined with a hard, bristly skin and they are used to transport the food between the place where it is found and picked up to the cave nest, i.e. at home in the cage between food bowl and sleeping den.

The oesophagus is a pure transport organ. From the mouth, the well-chewed food reaches the further digestive tract. Well-chewed food pulp is called chymus and is now admitted to the actual food utilisation process. Pharynx and oesophagus of course also convey the drinking water.

The stomach of hamsters is made up of two parts. One distinguishes the gastroesophageal vestibule for the intermediate storage and soaking of the food ingredients and another sector. This second part of the stomach is the glandular stomach and many experts even speak of a second stomach. However, in hamsters, the delimitation is not quite as clear as in birds. After chewing in the mouth and soaking in the gastroesophageal vestibule section, the actual digestive process now starts at this point and first molecules of the food's ingredients are broken down. Special cells vigorously acidify the food with hydrochloric acid. In this acidic medium, enzymes that decompose proteins start with protein utilisation and stomach hormones are poured out as signal. All hormones act as internal neurotransmitters of the body inside and are "sent out" via the bloodstream. The stomach musculature around the stomach ensures both that the stomach content is well mixed and that the stomach is emptied. This refers to the transfer of food pulp by the sphincter (also called pylorus) at the end of the glandular stomach section into the further alimentary tract.

In the front part of the small intestine, a copious amount of lymph and enzymes is added to the food pulp to let the further utilisation steps take place in a thin fluid stage.

1After a few millimetres, the outlets of pancreas and liver empty into the small intestine. The liver is able to store an excess of blood sugar for a short time in the form of glycogen, but apart from that, it is mainly responsible for central "detoxication". In addition, it is the origin of bile, which "buffers" the gastric juices and transforms them from an acidic to an alkaline medium. The pancreas regulates the blood sugar level and contributes ferments breaking down both fat and carbohydrates.

This section is followed by the rear part of the small intestine, where the main digestive process is taking place. The extremely active intestinal villus tissue transfers the decomposed products from the food to the bloodstream. Only components of food ingredients that have been split up to the greatest possible extent are able to pass the intestinal wall and are thus available for utilisation by other organs in the hamster's body. The rear part of the small intestine is the region where all nutrients and active substances that have been digested up to then are transferred to the organism. A wrong diet with too fatty and sweet food or one that contains an excess of oilseeds causes most of the problems especially in the small intestine. It is predominantly at this point where preventive health care, i.e. ensuring an optimum provision with ideal modern animal nutrition products, takes effect. A good choice of food is vitally important for these animals! From this point onwards, the food pulp almost only contains so-called crude fibre, i.e. components of vegetable cell membranes from the food.

Where the small intestine empties into the colon area of the digestive tract, the blind gut branches off. It carries this name because it ends "blind", like a dead-end street. It is actually a fermenting chamber that is populated by a plethora of specialised bacteria. Here, some residual energy can still be extracted from plant parts that are rich in crude fibre and roughage and building blocks contained in the membranes of plant cells (in particular dextrose from cellulose) are extracted. Hamsters have a smaller appendix than for instance chincillas, rabbits or guinea pigs. All the same, abrupt changes in food should be avoided, because only then will the fermentation process in the appendix take place in a reliable manner. Contrary to many purely herbivorous rodents, concentrate eaters such as hamster, rats and mice do not form appendix droppings or soft intestinal droppings as separate types of excrements.

The main task of the remaining large intestine behind the transitional area small intestine/appendix is to recover water from the now already largely digested, but still quite thin food pulp. But further bacteria are living everywhere in the large intestine. Like their fellows or relatives in the appendix, they are capable of special fermentation and similar metabolic processes. They provide the cells in the intestinal wall with short-chain fatty acids from the food remnants, which however, are no longer able to reach the blood stream from here. In the rear section of the large intestine, the droppings are preshaped.

The rectum at last gives the dry faeces particles their final shape and in the process withdraws as much residual moisture from them as possible. Sometimes, hamsters also eat of these faeces lumps, but that is absolutely normal in all rodents. Diarrhoea or constipation are signs that the water regulation is disturbed because of problems in the preceding sections.

The anus is the discharge orifice for the faeces. These solid excrements contain waste products that cannot be excreted in liquid form via the kidneys as urine, as well as undigested food remnants or possibly individual or temporary nutriment excesses. The anal sphincter is situated at the end of the digestive tract.