JPS6214749A - Artificial feed for silkworm - Google Patents

Abstract

PURPOSE:To improve growth of silkworm and to aim improvement in yield of cocoon, by blending an artificial feed for silkworm with rice bran heat-treated with superheated steam. CONSTITUTION:Rice bran prepared as a by-product in polishing rice is heat- treated with superheated steam in an oxygen-free state, sterilized, enzymes such as lipase, etc., are deactivated, free fatty acids and their oxides contained in small amounts are vaporized and removed, to prepare thermally sterilized clean rice bran having improved shelf stability and rich nutrition. The thermally sterilized rice bran is optionally pulverized and added to an artificial feed for silkworm consisting of mulberry leaf powder, calcium carbonate, various vitamins, defatted soybean, yeast, starch, sucrose, glucose, beta-sitosterol, soybean oil, calcium carbonate, potassium phosphate, various vitamins, organic acid, etc., to give the aimed artificial feed for silkworm. The amount of heated rice bran added is properly <=about 10wt%.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an artificial feed for silkworms comprising rice bran heat-treated with superheated steam, and its purpose is to improve the growth of silkworms by using the artificial feed. The objective is to significantly improve the cocoon yield.

<Prior art> Much research and development has already been carried out on artificial feed for silkworms, and with regard to feeding, the composition of artificial feed has been studied based on the three factors of silkworm attraction, chewing, and swallowing.
Next, we will improve the growth rate, make the superfamily uniform, secure the cocoon yield,
Research has been conducted to improve silk quality, reduce the incidence of silkworm disease, etc., with the goal of achieving a level comparable to that of mulberry leaf breeding. Its basic composition includes protein sources such as mulberry leaf powder, soybean protein and yeast, various starches, carbohydrate sources such as cellulose powder, sucrose and glucose, soybean oil, lipids such as β-sitosterol, other organic acids, and vitamins. A variety of artificial feeds containing minerals, minerals, etc. have been developed, and silkworm rearing from the young stage to full-scale rearing is now being carried out, and rearing results comparable to those of mulberry leaf rearing are being achieved.

However, practical issues are being pursued further, and for example, from the perspective of cost, reduction or complete elimination of mulberry leaf powder, elimination of addition of cellulose powder, etc. are being considered, and improvements in growth, cocoon yield, etc.
Research is also continuing into new additives that can further improve thread quality.

<Problems to be Solved by the Invention> As mentioned above, research has been carried out on various compositions and combinations of additives, etc. based on feeding properties, and artificial feeds have been put into practical use.

However, further uniformity of silkworm growth and promotion of its growth are important issues, especially for the artificial rearing of young silkworms in the 1st to 3rd instar stages.

In other words, the greatest responsibility of the joint nursery farms for silkworms in each region is to supply healthy grown silkworms to the sericulture farmers under their umbrella. Uniform weight gain for silkworms is extremely advantageous for communal farms, as silkworms are traded by weight. Also, for silkworm farmers, obtaining silkworms whose weight has increased uniformly will lead to an increase in the weight of each cocoon if these silkworms form a mask, which will increase the cocoon weight and increase profitability. will be improved.

Therefore, the present inventors aimed to promote the growth of young silkworms in the 1st to 3rd instar stage and to make the growth uniform, or to equalize the development of mature silkworms at the end of the 5th instar stage in full-term artificial rearing, to shorten the length of the upper stage, and to improve the uniformity of the growth of young silkworms. improved yield,
We started developing artificial feed for the purpose of reducing labor.

First, we focused on rice bran, which has been widely used as a basidiomycete culture medium, plant fertilizer, livestock feed, etc. because it contains excellent nutritional components.

However, raw rice bran contains a large amount of lipids, and during storage, the lipids are decomposed or oxidized due to the action of lipase, etc. contained in raw rice bran, and free fatty acids and their oxides are generated. It was considered that the raw rice bran could be defatted to improve its shelf life, but the effective lipids would be removed and the calories would be reduced. Due to heating in the air, there are problems such as destruction of vitamins and undesirable oxidation of some lipids, so even if artificial feed is prepared using these, it is not suitable for feeding silkworms. It turned out to be unsuitable.

<Means for Solving the Problems> The present inventors prepared a new artificial feed by blending rice bran heat-treated with superheated steam under appropriate conditions into a conventionally known artificial feed for silkworms. By feeding and rearing the young silkworms during the young silkworm period or the entire period, the young silkworms grow uniformly throughout the period and exhibit weight gain with little variation, and the amount of weight gain is also lower than that of conventional artificial artificial silkworms. It was found that the growth was significantly larger than that of feed, and growth could be promoted.

The present invention was made based on the above findings, and provides an artificial feed for silkworms containing rice bran heat-treated with superheated steam.

The present invention will be explained in detail below.

First, the rice bran used in the present invention is made by heating and sterilizing the rice bran, which is a by-product when milling rice, with superheated steam in an oxygen-free state. As the process progresses, it is preferable to use something as fresh as possible.

The rice bran may be used as it is, or if necessary, it may be ground using a common grinder or the like.

Next, the heat treatment in the present invention will be specifically described.

The heat treatment apparatus used in the present invention can be of any shape or structure, regardless of whether it is a continuous type or a batch type.
The continuous steaming and heating apparatus described in Japanese Patent No. 47767 is particularly suitable.

Put the rice bran into the above heat treatment equipment and set the pressure to Okg/ctl.
In the presence of superheated steam at a pressure of -G or higher, at a temperature of 120~
300''C1, preferably at 150 to 250°C for 1 second or more, preferably 2 to 30 seconds by direct contact, and then discharged under the same pressure or a lower pressure to obtain heat-treated rice bran.

As mentioned above, by heating rice bran in the presence of superheated steam in an oxygen-free condition, enzymes such as lipase are deactivated.
Furthermore, free fatty acids and their oxides, etc., produced are scattered and removed, albeit in small amounts, due to the enzymatic action that begins at the same time as the whitening operation. Moreover, since the heat treatment is performed in an oxygen-free condition, vitamins and other substances are not destroyed, and most of the bacteria and pest eggs are also killed, making it a clean and nutritious heat-sterilized rice bran that has an extremely long shelf life. Become. Rice bran treated in this way has significantly reduced repellency to silkworms,
Therefore, even if it is mixed with other ingredients and used as artificial feed, it will not have any adverse effects on storage stability, feeding ability, or other aspects of rearing.

In addition, when the rice bran is brought into direct contact with superheated steam at a temperature of less than 120°C, the scattering and sterilization of free fatty acids and their oxides in the rice bran are insufficient, and conversely, the temperature of the superheated steam becomes extremely high. When the temperature is high, for example, above 300°C, rice bran develops a bitter taste and burnt odor, making it unsuitable as artificial feed for silkworms.

The heat-sterilized rice bran thus obtained can be further pulverized if necessary, and then effectively used as an artificial feed composition for silkworms.

The artificial feed composition to which real rice bran should be added includes, for example, mulberry leaf powder, defatted soybeans, protein sources such as yeast, starch, sucrose, etc.
It contains carbohydrate sources such as glucose, lipid sources such as β-sitosterol and soybean oil, inorganic salts such as calcium carbonate, magnesium sulfate, and potassium phosphate, various vitamins, organic acids, and other conventionally known artificial feed ingredients. used.

The amount of heated rice bran added to the above artificial feed is 10% by weight.
When adding it, it can be added to the above artificial feed formulation by cutting it externally, or it can be added inside by replacing one or more of the components or by reducing the blending ratio of one or more components. Prepare artificial feed for use.

The artificial feed for silkworms that has been uniformly mixed and prepared in this way is shipped as it is, for example, in 10 to 30 kg units, packaged in moisture-proof bags, etc., and the moisture content is adjusted by adding a predetermined amount of water at a silkworm breeding farm. After thoroughly mixing the mixture and watering it uniformly, sterilizing it by a conventional method, it is made into paste feed, which is cut into squares or rolled into a film, and then fed to the silkworms.

In this way, by feeding artificial feed containing heat-sterilized rice bran according to the present invention from the young silkworm stage, the growth of silkworms is promoted,
Cocoon yield can be improved.

<Example> Hereinafter, the present invention will be explained by giving examples.

Example 1 Rice bran (moisture: 11.5%, acid value: 9, general viable bacteria count: 3.
8X to 6, heat-resistant bacteria count: L, 0X102, coliform bacteria: +) using a continuous small-sized instant heat sterilizer (Special Publication 56-
47767) at a feed rate of 200 kg/H, and the pressure was 1 and Okq/H within the device.
ctA-G was brought into direct contact with superheated steam at a temperature of 180° C. for 15 seconds, and then passed through the cooling section of the apparatus and cooled to room temperature.

Then, the operation was continued for 5 hours and heat sterilized rice bran (moisture = 5.
9%, acid value: 6, general viable bacteria count: 30 or less, heat-resistant bacteria count =
20 or less, coliform group: -) 930&g was obtained.

In addition, a portion of the above-mentioned heated rice bran was packaged in 1 kg polyethylene bags, and the acid value (
Experimental Agricultural Chemistry, Volume 2, p. 458, April 15, 1972.
When we measured the actual heated rice bran (Japanese edition, 11th edition), the actual heated rice bran was 8.
On the other hand, the control was 9 at the time of storage, but it was 3
It rose to 8, indicating that the heated rice bran had excellent storage stability and was stable.

Next, for the basic feed listed in Table 1,
heated rice bran stored for 30 days at 0% by weight (
Artificial feeds for silkworms A, B, C, and D were prepared by adding (control), 1%, 3%, and 5% and mixing them uniformly.

Table 1 Basic Feed Next, 5oOy (anhydrous weight) units of each feed obtained in this way were adjusted to 70% moisture and fed to 1 kg/ca.
G: Heat sterilized for 30 minutes and reared using the flat plate feeding method.

Silkworms (variety: Kanewa × Kinshu) were numbered 3,000 per test plot, and the first instar stage was kept at 30°C, humidity 95%, and the second instar stage was kept at 28°C.
The animals were kept aseptically in total darkness for 5 days in an environment with 90% humidity. The breeding results are shown in Table 2.

Table 2 As shown in Table 2, as a result of rearing silkworms for 5 days until the second instar stage using feeds containing rice bran heat-treated with superheated steam (B, C, D), only the basic feed (A ), the body weight increased in all cases, and the 3% addition group (C) was particularly excellent.

Example 2 Two types of feeds, symbol A (no addition of heated rice bran) and symbol C (addition of 3% heated rice bran), of Example 1 were prepared, and the number of animals per test area was 3000, and the 1st to 2nd instar period was as in Example The animals were reared in the same manner as No. 1, and the third instar was kept at 26° C. and the humidity was 85%, and the fourth and fifth instars were fed mulberry leaves. 10 days later (during 3 sleeps)
Table 3 shows the weight and drawing results of the subjects.

As shown in Table 3, the weight gain of the silkworms reared with the feed according to the present invention was large after 10 days, and therefore, an increase in both cocoon weight and cocoon layer weight was observed when the silkworms were grown into cocoons, and the silk quality was also good. Met.

<Effects of the Invention> The present invention replaces rice bran, which conventionally has excellent nutritional components but cannot be stored due to rotting or deterioration of quality due to free fatty acids and their oxides generated during storage. By heating and sterilizing with superheated steam, harmful free fatty acids and their oxides are removed, resulting in a clean and highly nutritious rice bran with an extremely long shelf life.This rice bran can be added to artificial feed for silkworms to create a new type of silkworm feed. It is used as artificial feed.

By using this feed to feed and raise the silkworms during the young period or during the whole period, the young silkworms grow uniformly without having any negative effects on feeding habits or other breeding conditions, making it possible to use artificial feeds that are conventionally used. The present invention shows a significant increase in body weight compared to the sericulture industry, and therefore the cocoon weight etc. also increases and good quality of thread can be obtained. It is possible to improve the profitability etc. of sericulture and contribute to the sericulture business.

Claims (1)

[Claims] Artificial feed for silkworms containing rice bran heated with superheated steam.