JP7768503B2 - animal feeding device - Google Patents

Description

The present invention relates to an animal feeding device that is used to administer liquid compositions such as milk or medicinal solutions, particularly liquid compositions with high viscosity that tend to clog pores, such as high-protein artificial milk, to small animals, including experimental animals such as mice and rare animals, by allowing them to spontaneously suckle.

During the developmental period of mammals, from birth to maturity, it is impossible to evaluate the nutrient needs of the animal body from neonatal to maturity, the effectiveness of pharmaceuticals, the safety of chemicals, immune formation, and the effects of various stresses during infancy on maturity and beyond in mature individuals. Therefore, pharmacokinetics and biological functions within the animal body during the developmental period must be investigated in the actual developing animal. When conducting such research on individual rodents (mice and rats) shortly after birth, the newborn is separated from its mother within 48 hours of birth and artificially raised on formula until weaning. Individuals at this stage are equivalent to premature babies in human terms, with their eyes and ears not yet fully developed, and their organs not yet fully developed, making them highly susceptible to drugs and other substances. This makes it possible to expect to obtain highly accurate data.

Until now, artificial feeding of rodents has involved intubating the stomach at four days of age and injecting artificial milk or liquid medicine (Non-Patent Document 1), but this has posed many problems, including leakage of the artificial milk or liquid medicine. Subsequently, artificial feeding bottles and nipples were developed (Patent Document 1), but they had complex structures, durability issues, and required considerable skill to use.

In addition, bottle-feeding using conventional formula has the problem of not being able to fully achieve growth equivalent to that achieved by breastfeeding, and known bottles and nipples (Patent Document 1) are prone to clogging, making it necessary to continue using conventional formula. Furthermore, conventional bottles and nipples (Patent Document 1) have complex structures and include parts that cannot be disassembled, making it difficult to clean the equipment after formula feeding. Furthermore, high-temperature sterilization using an autoclave or other method has the disadvantage of gradual discoloration due to residual traces of protein in the formula.

Patent No. 4540324

Francis, F., et al., Probiotic Studies in Neonatal Mice Using Gavage. J. Vis. Exp. (143), e59074, doi:10.3791/59074 (2019)

The present invention aims to develop a high-protein formula that is suitable for achieving growth equivalent to that achieved by breast-feeding through artificial feeding, and to provide an animal-feeding device of a novel design that is suitable for artificially feeding such high-protein formula; the device is simple in structure, easy to disassemble and clean, and easy to disinfect and sterilize; highly durable; and does not require skilled techniques for use. Another objective of the present invention is to provide an artificial-feeding method that uses an animal-feeding device of such a novel design to perform artificial feeding.

The inventors of the present invention discovered that the metal thin tube attached to the nipple portion of a known artificial feeding device (Patent Document 1) inhibits feeding of a high-protein liquid composition, and discovered that by improving the nipple portion of the feeding device so that the thin tube is not necessary, it is possible to provide an animal feeding device that can also artificially feed a high-protein liquid composition, and further discovered that it is possible to provide an animal feeding device that is easy to disassemble overall and has a reduced number of parts, has a simple structure that is easy to disassemble and clean, is highly durable, and is easy to use, and thus completed the present invention. Specifically, the present invention relates to:
a nipple member (10) made of an elastic material having a nipple portion (11) and a pore (12) at the tip of the nipple portion (11) through which liquid can be discharged;
a liquid reservoir member (20) connected to the nipple member (10) and having an opening (21) for supplying liquid into the nipple member (10) from the connected portion;
By providing an animal nursing device (1) including the above, it is possible to provide an animal nursing device with a novel structure that solves the above problems.

More specifically, the present application provides the following aspects to solve the above-mentioned problems:
[1]: A nipple member made of an elastic material having a nipple portion and a hole at the tip of the nipple portion through which liquid can be discharged;
an animal feeding apparatus including a liquid reservoir member connected to the nipple member and having an opening for supplying liquid from the connected portion into the nipple member;
[2]: The animal feeding device according to [1], including a teat portion filling member made of an elastic material that is filled at least inside the teat portion;
[3]: The animal feeding device according to [2], wherein the elastic material is silicone rubber, isoprene rubber, styrene-isoprene rubber, urethane, or a sponge-like material thereof;
[4]: The animal feeding device according to any one of [1] to [3], further comprising a milk replenishing member connectable to the liquid reservoir member and capable of supplying liquid into the liquid reservoir member;
[5]: The animal feeding device according to any one of [1] to [4], in which the nipple member does not include a metal capillary tube;
[6]: The animal feeding device according to any one of [1] to [5], in which all components are separable from each other;
[7]: The animal feeding device according to any one of [1] to [6], which prevents leakage of liquid from the pores in the nipple portion by surface tension;
[8]: The animal feeding device according to any one of [1] to [7], wherein the internal pressure of the animal feeding device becomes negative when the animal sucks the liquid from the nipple portion, and the liquid in the liquid reservoir member is supplied into the nipple member;
[9]: The animal feeding device according to any one of [1] to [8], which is capable of supplying a high-protein liquid;
[10]: Animal formula containing up to 15 g of protein per 100 ml;
[11]: The animal formula according to [10], wherein the animal is a rodent;
[12]: The animal formula according to [10] or [11], containing 10.5 to 15 g of protein per 100 ml;
[13]: The animal formula according to any one of [10] to [12], wherein the protein comprises casein, whey protein isolate (WPI), whey protein hydrolysate (WPH), or any combination thereof;
[14]: An animal formula according to any one of [8] to [13], wherein the ratio of casein to whey (WPI + WPH) is 2:1 to 1:2.5.

By inventing the novel animal feeding device described above, the present invention simplifies the structure of the feeding bottle, achieving overall ease of disassembly and a reduced number of parts. Its simple structure allows for easy disassembly and cleaning, and its excellent durability facilitates cleaning, disinfection, and sterilization, as well as the ability to perform feeding techniques such as artificial feeding with liquid compositions that tend to clog, such as high-protein formula. This makes it possible for even beginners to artificially feed not only mice and rats using liquid compositions such as high-protein formula, but also small wild mammals. As a result, the animal feeding device of the present invention makes it possible to evaluate not only the intake of various nutrients, the administration of pharmaceuticals, and exposure to chemicals during growth and development, but also the effects of the rearing environment, as well as changes after maturity. It also makes it possible to artificially feed wild animals that require protection. Furthermore, it also makes it possible to more accurately and easily evaluate the effects of various high-protein formulas on growth.

FIG. 1 is a side view of an animal feeding device (1) of the present invention. FIG. 2 shows a side view of the nipple member (10). FIG. 3 is a view of the nipple portion (11) seen from the pore (12) side, showing examples of the shape of the pore (12). Figure 4 shows the nipple portion (11) viewed from the pore (12) side, illustrating examples of the shape of the pore (12). Figure 4 shows a midline cross section of the liquid reservoir member (20), illustrating examples of the location of the refill opening (22). FIG. 5 shows an example of the manufacture of an animal feeding device (1) of the present invention, showing the component configuration (FIG. 5(a)) and the assembled state (FIG. 5(b)). FIG. 6 is a graph comparing the weight gain over a 28-day rearing period between an artificially reared group using the animal nursing device of the present invention and a naturally reared group in which the animals were spontaneously nursed by their mothers.

The present invention provides an animal feeding device having a novel structure that is simple in structure, easy to disassemble and clean, has excellent durability, can feed liquid compositions that are prone to clogging, such as high-protein formula, and does not require skilled techniques for use.
a nipple member (10) made of an elastic material having a nipple portion (11) and a pore (12) at the tip of the nipple portion (11) through which liquid can be discharged;
a liquid reservoir member (20) connected to the nipple member (10) and having an opening (21) for supplying liquid into the nipple member (10) from the connected portion;
The present invention provides an animal feeding device (1), comprising:

<Overall configuration of animal feeding device (1)>
As shown in Figure 1, the animal feeding device (1) of the present invention comprises a nipple member (10) and a liquid reservoir member (20) connected to the nipple member (10) and in liquid communication with the nipple member (10) through an opening (21). The animal feeding device (1) may be connected to a liquid component replenishing member (30) through a replenishing opening (22) provided in the liquid reservoir member (20).

<Nipple member (10)>
As shown in FIG. 2, the nipple member (10) has a nipple portion (11) for discharging liquid components contained inside the animal feeding device (1), and an opening for supplying liquid components contained in a liquid reservoir member (20) described below to the nipple member (10).

The nipple member (10) may have any shape as long as it can be molded, and may, for example, be hemispherical or conical, which are relatively simple structures.

The animal to be sucked can hold the nipple portion (11) in its mouth, suck on it spontaneously, just as it spontaneously sucks milk from its mother's nipple, and drink the liquid in the animal suckling device (1). To achieve this feature, the size of the nipple portion (11) may vary depending on the animal to be suckled, and it is preferable to adjust it to a size similar to that of the mother's nipple.

Furthermore, to achieve this feature, it is advisable to make the hardness of the teat portion (11) similar to that of the teat of the dam. This hardness is determined by the thickness of the material of the teat portion (11) and the hardness of the teat portion filling member (12), which will be described later. If the thickness of the material of the teat portion (11) is made thinner (the hardness of the teat portion (11) itself decreases), the hardness of the teat portion filling member (12) can be increased accordingly, thereby maintaining the overall hardness. Conversely, if the thickness of the material of the teat portion (11) is made thicker (the hardness of the teat portion (11) itself increases), the hardness of the teat portion filling member (12) can be decreased accordingly, thereby maintaining the overall hardness.

The tip of this nipple portion (11) is characterized by having a pore (12) that can discharge the liquid contained inside the nursing device (1). This pore (12) may be of any shape, and as shown in Figure 3, when the nipple member (10) is viewed from the nipple portion (11) side, it may be a circular pore (Figure 3(a)) or a pore with a cross-shaped notch running through it (Figure 3(b)). Furthermore, the size of the pore (12) may be any size as long as it does not allow the liquid components contained inside the nipple member (10) to flow out.

The nipple member (10) may be made of any material that is flexible, washable, and can be sterilized using an autoclave or other sterilization method. For example, materials such as silicone rubber, natural rubber (latex, etc.), chloroprene rubber, nitrile rubber, butyl rubber, ethylene propylene rubber, urethane rubber, and isoprene rubber can be used.

The nipple member (10) can be molded by any molding method commonly used in the art, as long as it can create the structure of the nipple member (10). For example, it can be created by coating molding, in which a molten material is coated onto the surface of a mold to create the entire structure.

Compared to nipple members of conventional nursing devices (Patent Document 1), the nipple member (10) is characterized by the absence of a metal capillary tube. The absence of a metal capillary tube offers the benefits of increased disassembly, a simpler structure, ease of disassembly and cleaning, and ease of disinfection and sterilization.

<Nipple portion filling member (13)>
A nipple portion filling member (13) made of an elastic material may be placed as an optional member inside at least the nipple portion (11) of the nipple member (10) to fill the interior of the nipple portion (11). This nipple portion filling member (13) is designed so that when the target animal holds the nipple portion (11) in its mouth and sucks, the liquid component accumulated inside the elastic material is expelled into the target animal's mouth through the pores (12) due to its elasticity. This nipple portion filling member (13) is necessary when supplying a thin liquid component with a relatively low protein concentration, but is not essential when the liquid component inside is high in protein.

The nipple portion filling member (13) is made of an elastic material. In the present invention, the elastic material may be silicone rubber, isoprene rubber, styrene-isoprene rubber, urethane, or a sponge-like version of any of these, but is not limited to these materials. A nipple portion filling member (13) made of such a material may be either disposable or reusable, but can be reusable if made of a material that can withstand autoclave sterilization.

The shape of the nipple portion filling member (13) needs to be such that it fills at least the inside of the nipple portion (11), and the outer shape of the nipple portion filling member (13) needs to roughly match the inner shape of the nipple portion (11).

The nipple portion filling member (13) does not need to be molded integrally with the nipple member (10); it can be made independently of the nipple member (10) and fitted into the nipple portion (11) when in use.

The nipple portion filling member (13) prevents the liquid component from flowing out of the pores (11) due to the surface tension that arises between the material and the liquid component when the liquid component penetrates between the sponge-like material.

<Liquid reservoir member (20)>
The nipple component 10 described above is used by connecting a liquid reservoir component 20. The liquid reservoir component 20 is connected to the nipple component 10 via its opening 21, and is used in a state where liquid is communicated between them.

When the target animal sucks on the nipple portion (11) and the liquid component inside the nipple member (10) is expelled, a slight negative pressure is created inside the nipple member (10), or the nipple member (10) deforms as the liquid component inside the nipple member (10) decreases. In such a case, the liquid component stored in the liquid reservoir member (20) is supplied to the nipple member (10) by the pressure caused by the slight negative pressure inside the nipple member (10), by applying pressure manually or mechanically from the outside, or by external pressure such as gravity.

The liquid reservoir member (20) can be connected to the nipple member (10) at its opening (21) without leaking the liquid components, and can be made of any material that can be washed and sterilized using an autoclave or other sterilization procedures. Examples of materials that can be used include plastic materials (such as syringes), silicone rubber, glass, and fluororesin. The end opposite the opening (21) can be either an open end or a closed end.

The liquid reservoir member (20) may be marked with a scale to allow for a rough understanding of the amount of liquid component aspirated by the target animal. For example, by making the side opposite the opening (21) the open end, when the liquid component inside the liquid reservoir member (20) is supplied to the nipple member (10) by gravity, the scale on the liquid reservoir member (20) can be used to measure the amount of liquid component to be supplied. Furthermore, if it is desired to measure the amount of liquid component more accurately, a liquid reservoir member (20) made of a material and shaped like an injection syringe can be used, and by applying pressure to the plunger, the liquid component can be supplied into the nipple member (10) and the amount of liquid component aspirated by the target animal can be measured relatively accurately.

The liquid reservoir member (20) may be provided with a refill opening (22) for refilling the liquid component inside the liquid reservoir member (20), separate from the opening (21) for connection to the nipple member (10). The refill opening (22) may be located anywhere in the liquid reservoir member (20) other than the opening (21) of the liquid reservoir member (20). For example, in the case of a liquid reservoir member (20) shaped as shown in Figure 4, the refill opening (22) may be located on the side of the liquid reservoir member (20) in relation to the opening (21), or on the opposite end of the opening (21).

<Liquid component replenishing member (30)>
The liquid reservoir member (20) can be connected to a liquid component replenishing member (30) via the replenishing opening (22). This liquid component replenishing member (30) can replenishing the liquid component inside the liquid reservoir member (20) while the liquid reservoir member (20) and the nipple member (10) remain connected.

In Figure 1, the liquid component replenishing member (30) is shown as having a generally tubular shape, but the liquid component replenishing member (30) may be formed by connecting any other shape of component outside the drawing to the tubular liquid component replenishing member (30). For example, the liquid component replenishing member (30) may be formed by connecting an injection syringe to the tubular liquid component replenishing member (30).

<Features of Animal Feeding Device (1)>
The animal feeding device (1) configured as described above is characterized in that each of the components, the nipple member (10), nipple portion filling member (13), liquid reservoir member (20), and liquid component replenishing member (30), can be disassembled and easily cleaned. By making each component from a sterilizable material, these components can be sterilized before use, then reassembled and reassembled into the animal feeding device (1). Each of these components may be made disposable, if necessary.

The artificial feeding method using the animal feeding device (1) of the present invention enables the feeding of fixed amounts of liquid ingredients, making it possible to more accurately evaluate than previous methods the influence of various nutrient intakes, pharmaceutical administration, and chemical exposure during growth and development, as well as the influence of rearing environment, and changes after maturity. As a result, the animal feeding device (1) of the present invention can be applied to all research fields related to growth and development, including functional foods, including foods for specific dietary uses, aimed at maintaining and promoting the health of children, as well as basic research related to the development of pharmaceuticals in pediatric settings such as NICUs and PICUs for premature and preterm infants. Furthermore, it has become possible to more accurately and simply evaluate the effects of various high-protein formulas on growth.

Another feature of the animal feeding device (1) of the present invention is that it can be used to feed liquid compositions that are prone to clogging, such as high-protein formula.

For example, rat breast milk contains 10.5±1.5 g of protein per 100 mL of milk (i.e., 9.0-12.0 g per 100 mL of milk) (Journal of Pediatric Gastroenterology and Nutrition 24, 242-252(1997)). In contrast, conventional formulas contain approximately 9.2-9.5 g of protein per 100 mL of formula (actual values: Journal of Pediatric Gastroenterology and Nutrition 24, 242-252(1997)), 9.4 g (Exp. Anim. 55(4), 391-7, 2006), or 10.1 g (Lipids. 44(8), 685-702, 2009). The reason why the protein content could not be increased to the average protein content of rat milk (10.5 g/100 mL milk) is thought to be because as the protein content of formula increases, it becomes more susceptible to clogging in conventional feeding devices.

On the other hand, when using the animal feeding device (1) of the present invention, the simplified structure of the nipple member (10) makes it possible to feed even high-protein formula, for example, with a protein content of approximately 15.0 g per 100 ml of formula.

Accordingly, the animal feeding device of the present invention is capable of feeding liquid compositions ranging from low-viscosity liquid compositions with low protein content to liquid compositions prone to clogging with protein contents of up to 15.0 g per 100 ml of formula.

In addition, because the structure of each component is simple, it is easy to change the size of the nipple portion (11), making it possible to configure the animal nursing device (1) to suit a variety of animal species. For example, it is expected to be applicable to rare small animals that are difficult to breed and raise.

<Animal artificial milk>
As described above, the animal feeding device (1) of the present invention is characterized by its use in feeding liquid compositions that tend to clog, such as high-protein formula. That is, the animal feeding device (1) of the present invention is capable of feeding liquid compositions ranging from low-viscosity liquid compositions with low protein content to liquid compositions that tend to clog, with protein contents of up to 15 g per 100 ml of formula, and is particularly capable of feeding liquid compositions with protein contents equal to or greater than the average protein content of rat milk (10.5 g/100 mL milk).

Thus, in one aspect, the present invention can provide an animal formula containing up to 15 g of protein per 100 ml.

Here, animal artificial milk can be applied to small mammals, and a specific example of this is rodents. These animals may be laboratory animals or wild animals in need of protection.

The animal formula of the present invention is characterized by containing 15 g of protein per 100 ml. This protein concentration was such that previous animal feeding devices (Patent Document 1) were unable to use it due to clogging. In particular, rat milk is known to contain 10.5±1.5 g of protein per 100 ml (i.e., 9.0 to 12.0 g/100 ml) (Journal of Pediatric Gastroenterology and Nutrition 24, 242-252 (1997)). Therefore, the animal formula of the present invention preferably contains a protein content equal to or greater than the average protein content of rat milk, i.e., 10.5 g or more of protein per 100 ml of formula. In other words, the animal formula of the present invention preferably contains 10.5 to 15 g of protein per 100 ml of formula.

The protein contained in the animal formula of the present invention is composed of proteins including casein, whey protein isolate (WPI), whey protein hydrolysate (WPH), or any combination thereof. Here, "whey," also known as milk serum, is a type of protein contained in milk secreted by the mother and is highly soluble in water. "Casein" refers to the insoluble solid component remaining after fat and whey are removed from milk. Whey is characterized by rapid digestion and absorption, while casein is characterized by slow digestion and absorption.

Whey protein can be whey protein isolate (WPI) or whey protein hydrolysate (WPH), or a combination. WPI is a highly concentrated whey protein that has been further ion-exchanged to remove most non-protein components. WPH is whey protein that has been hydrolyzed with enzymes or other methods to separate it into peptides.

Among the proteins contained in the animal formula of the present invention, the ratio of casein to whey (WPI + WPH) is preferably 2:1 to 1:2.5. The rat milk in the aforementioned literature contains casein to whey (WPI + WPH) in a ratio of 2:1 (Journal of Pediatric Gastroenterology and Nutrition 24, 242-252 (1997)). Other conventional formulas contain casein to whey (WPI + WPH) in ratios of 5.75:3.64 or 5.40:3.60 (Exp. Anim. 55(4), 391-7, 2006), and one containing casein to whey (WPI + WPH) in a ratio of 3.46:7.64 (Lipids. 44(8), 685-702, 2009). On the other hand, the animal formula used in the examples of the present invention contains casein and whey (WPI + WPH) in a ratio of 4.0:9.0.

The following examples illustrate the present invention. The examples below are not intended to limit the present invention in any way.

Example 1: Construction example of animal feeding device (1) In this example, a construction example of an animal feeding device (1) of the present invention is shown.

In this embodiment, the nipple member (10), liquid reservoir member (20), and liquid component replenishing member (30) are all made of silicone rubber (Figure 5(a)). The assembled components are shown in Figure 5(b). An injection needle is connected to the liquid component replenishing member (30), and an injection syringe containing the liquid component is connected to this needle.

The nipple portion filling member (13) that fills the nipple portion (11) of the nipple member (10) is made of a sponge-like material made of urethane.

The pores (12) in the nipple portion (11) were circular pores as shown in Figure 3(a).

The refill opening (22) in the liquid reservoir member (20) was provided on the side of the liquid reservoir member (20) shaped as shown in Figure 4, resulting in the final configuration shown in the figure (Figure 5(b)).

Each component was autoclave sterilized at 120°C for 30 minutes, then dried and assembled to form the animal feeding device (1).

Example 2: Example of animal feeding using the animal feeding device (1) In this example, an example of animal feeding using the animal feeding device (1) of the present invention constructed in Example 1 is shown.

C57BL/6J mice purchased from Charles River Japan were used as animals, and the offspring were divided into an artificially fed group of eight and a naturally fed group of eight. The former were artificially fed using the animal artificial feeding device of the present invention, while the latter were naturally fed by the pups spontaneously suckling from their mother's milk, and their growth was compared based on changes in body weight.

During the study period, the artificially fed group voluntarily sucked on the nipple of a feeding device with formula containing 14.5 g of protein per 100 ml of formula, every three hours for 12 hours from 8:00 AM to 8:00 PM every day. On the other hand, the natural-feeding group was allowed to freely and voluntarily breastfeed 24 hours a day.

Animal formula used in artificially fed groups contains the following ingredients as its main nutritional components:

Figure 6 shows the changes in weight gain over a 28-day rearing period for the artificially fed group using the animal feeding device of the present invention and the naturally fed group, in which the animals were spontaneously fed by their dams. In Figure 6, A (AR) represents the artificially fed group, and Dam represents the naturally fed group. It was confirmed that the artificially fed group, which was fed with high-protein formula, also showed similar infant growth (weight gain) to the naturally fed group.

By inventing the animal feeding device with the above-mentioned novel configuration, the present invention simplifies the structure of the feeding bottle, achieving overall ease of disassembly and a reduced number of parts. Its simple structure allows for easy disassembly and cleaning, and it is highly durable, facilitating cleaning, disinfection, and sterilization, as well as the ability to perform feeding techniques such as artificial feeding with liquid compositions that tend to clog, such as high-protein formula. This makes it possible for even beginners to artificially feed mice and rats using liquid compositions such as high-protein formula. As a result, by using the animal feeding device of the present invention, it is possible to evaluate not only the intake of various nutrients, the administration of pharmaceuticals, and exposure to chemicals during growth and development, as well as the effects of the rearing environment, but also changes after maturity. Furthermore, it is now possible to more accurately and easily evaluate the effects of various high-protein formulas on growth.

1: Animal feeding device
10: Nipple member
11: Nipple part
12: Pore
13: Nipple filling member
20: Liquid reservoir member
21: Opening
22: Refill opening
30: Liquid component refilling component

Claims (14)

a nipple member made of an elastic material having a nipple portion and a hole at the tip of the nipple portion through which liquid can be discharged;
a liquid reservoir member connected to the nipple member and having an opening for supplying liquid from the connected portion into the nipple member;
Including,
A feeding device for rodents that does not include a metal capillary in the nipple member. 2. The feeding device for rodents according to claim 1, further comprising a nipple portion filling member made of an elastic material, which is filled at least inside the nipple portion. 3. The feeding device for rodents according to claim 2, wherein the elastic material is silicone rubber, isoprene rubber, styrene-isoprene rubber, urethane, or a sponge-like material thereof. 4. A rodent feeding apparatus according to any one of claims 1 to 3, further comprising a milk supply member connectable to the liquid reservoir member and capable of supplying liquid into the liquid reservoir member. 5. A feeding device for rodents according to any one of claims 1 to 4, wherein all of the components are separable from one another. 6. The feeding device for rodents according to claim 1, wherein surface tension is used to prevent leakage of liquid from the pores in the nipple portion. A feeding device for rodents according to any one of claims 1 to 6, wherein when the animal sucks liquid from the nipple portion, the internal pressure of the nipple member becomes negative, and liquid in the liquid reservoir member is supplied into the nipple member. 8. The feeding device for rodents according to claim 1, which is capable of supplying a high-protein liquid. a nipple member made of an elastic material having a nipple portion and a hole at the tip of the nipple portion through which liquid can be discharged;
a liquid reservoir member connected to the nipple member and having an opening for supplying liquid from the connected portion into the nipple member;
a nipple portion filling member made of an elastic material, which is filled at least inside the nipple portion;
Including,
A small mammal feeding device that does not include a metal capillary in the nipple member. An animal artificial milk containing up to 15g of protein per 100ml, for use in filling a feeding device for rodents according to any one of claims 1 to 8 or a feeding device for small mammals according to claim 9 . The animal artificial milk according to claim 10 , which contains 10.5 to 15 g of protein per 100 ml. 12. The animal formula of claim 10 or 11 , wherein the protein comprises casein, whey protein isolate (WPI), or whey protein hydrolysate (WPH), or any combination thereof. The artificial animal milk according to any one of claims 10 to 12 , wherein the ratio of casein to whey (WPI + WPH) is 2:1 to 1:2.5. A set of a feeding device for rodents according to any one of claims 1 to 8 or a feeding device for small mammals according to claim 9, and an animal artificial milk containing up to 15 g of protein per 100 ml.