阅读说明：本技术 母猪浓缩料、基于该母猪浓缩料的母猪饲料及其制备方法 (Concentrated sow feed, sow feed based on concentrated sow feed and preparation method of sow feed ) 是由 吴永锋 毛雪梅 黄宏彬 于 2021-08-12 设计创作，主要内容包括：本发明公开了一种母猪浓缩料,包括以下组分,各组分重量百分比为：甜菜粕2％～8％,米糠0～8％,大豆皮0～6％,豆粕0～4％,鱼粉0～2％,膨化大豆0～10％,葡萄糖0～1％,蔗糖0～1％,膨化亚麻籽油粉0～2％,预混料4％,各组分重量百分比之和为20％。本发明实现了原料的简单化和配方的标准化(配方均是65％玉米+15％豆粕+20％母猪浓缩料,具有一致性),解决了采购流程、加工工艺繁杂、生产管理易出错等问题。本发明技术较大幅度的提高了饲料企业以及猪场生产中的生产效能,在饲料生产加工过程中,减少了不同原料进行不同粉碎工艺以及无需停产进行更换筛片,生产效能提高20％以上。(The invention discloses a sow concentrate which comprises the following components in percentage by weight: 2-8% of beet pulp, 0-8% of rice bran, 0-6% of soybean peel, 0-4% of soybean meal, 0-2% of fish meal, 0-10% of puffed soybean, 0-1% of glucose, 0-1% of sucrose, 0-2% of puffed linseed oil powder and 4% of premix, wherein the sum of the weight percentages of the components is 20%. The invention realizes the simplification of raw materials and the standardization of the formula (the formula is 65 percent of corn, 15 percent of soybean meal and 20 percent of sow concentrated feed, has consistency), and solves the problems of complicated purchasing process, complex processing technology, easy error production management and the like. The technology of the invention greatly improves the production efficiency in feed enterprises and pig farm production, reduces the number of different crushing processes for different raw materials and the number of screen pieces replaced without stopping production in the feed production and processing process, and improves the production efficiency by more than 20%.)

1. The sow concentrate is characterized by comprising the following components in percentage by weight: 2-8% of beet pulp, 0-8% of rice bran, 0-6% of soybean peel, 0-4% of soybean meal, 0-2% of fish meal, 0-10% of puffed soybean, 0-1% of glucose, 0-1% of sucrose, 0-2% of puffed linseed oil powder and 4% of premix, wherein the sum of the weight percentages of the components is 20%.

2. The sow concentrate of claim 1, wherein the premix comprises a replacement gilt premix, a pregnant sow premix, a heavy sow premix, a lactating sow premix, wherein:

the replacement sow premix comprises the following components in percentage by weight: 0.15% of choline chloride, 0.25% of lysine, 0.07% of methionine, 0.025% of phytase, 0.03% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.95% of stone powder, 0.71% of calcium hydrophosphate, 0.41% of sodium chloride, 0.015% of antioxidant, 0.01% of Nongmi, 0.01% of Eiwei XG10 enzyme, 0.5% of mildew adsorbent, 0.5% of zeolite powder and 0.27% of unite bran;

the pregnant sow premix comprises the following components in percentage by weight: 0.14% of choline chloride, 0.15% of lysine, 0.055% of methionine, 0.025% of phytase, 0.035% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.96% of stone powder, 0.72% of calcium hydrophosphate, 0.41% of sodium chloride, 0.015% of antioxidant, 0.01% of pesticide secret, 0.01% of Eiwei XG10 enzyme, 0.25% of Aichangbao, 0.5% of mildew adsorbent, 0.40% of zeolite powder and 0.22% of unite bran;

the heavy fetal sow premix comprises the following components in percentage by weight: 0.16% of choline chloride, 0.24% of lysine, 0.1% of methionine, 0.025% of phytase, 0.035% of composite vitamin of breeding pigs, 0.1% of composite mineral of breeding pigs, 0.97% of stone powder, 0.72% of calcium hydrophosphate, 0.43% of sodium chloride, 0.02% of antioxidant, 0.012% of Nongmi, 0.01% of EmuXG 10 enzyme, 0.3% of Aichangbao, 0.5% of mildew adsorbent, 0.278% of zeolite powder and 0.1% of unite bran;

the lactating sow premix comprises the following components in percentage by weight: 0.16% of choline chloride, 0.28% of lysine, 0.075% of methionine, 0.025% of phytase, 0.03% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.94% of stone powder, 0.72% of calcium hydrophosphate, 0.433% of sodium chloride, 0.02% of antioxidant, 0.012% of Nongmi, 0.012% of Eiwei XG10 enzyme, 0.3% of Aichangbao, 0.5% of mildew adsorbent and 0.393% of zeolite powder;

the compound vitamin for the breeding pigs comprises the following components in parts by weight: 10-150 parts of vitamin A, 310-50 parts of vitamin D, 100-600 parts of vitamin E, 33-30 parts of vitamin K, 11-10 parts of vitamin B, 25-60 parts of vitamin B, 62-20 parts of vitamin B, 121-20 parts of vitamin B, 2-20 parts of folic acid, 10-300 parts of biotin, 1-8 parts of nicotinamide and 3-30 parts of pantothenic acid;

the pig compound mineral comprises the following components in parts by weight: 2-8 parts of copper, 15-40 parts of iron, 15-25 parts of zinc, 8-20 parts of manganese, 8-20 parts of iodine, 1-5 parts of selenium and 1-4 parts of chromium;

the agricultural secret is one or a combination of a plurality of agricultural secrets-F and agricultural secret-S;

the Everka XG10 enzyme is a non-starch polysaccharide enzyme preparation comprising xylanase and B-glucanase;

the Aichangbao contains one or more of medium chain glycerol fatty acid ester, acidifier, and organic iron.

3. The sow concentrate of claim 1, wherein the antioxidant is a combination of one or more of I-ascorbic acid, butylated hydroxytoluene, butylated hydroxyanisole, tocopherol, and ethoxyquinoline.

4. The sow concentrate as claimed in claim 1, wherein the mold adsorbent is a composition of esterified glucomannan and antimicrobial peptide, and the mass ratio of the esterified glucomannan to the antimicrobial peptide is 1-5: 1 to 5.

5. The sow concentrate of claim 1, wherein the rice bran is defatted rice bran; the content of crude protein in the soybean meal is more than or equal to 43.0%.

6. The sow concentrate as claimed in claim 1, wherein the content of crude protein in the fish meal is 65.0% or more.

7. The sow concentrate of claim 1, wherein the expanded flaxseed oil meal has a crude fat content of at least 32%.

8. The sow feed is characterized by comprising a sow feed in a feeding-limited stage and a sow feed in a non-feeding-limited stage, wherein: the formula of the feed for the sows in the feeding-restricted stage and the formula of the feed for the sows in the non-feeding-restricted stage are 65 percent of corn, 15 percent of soybean meal and 20 percent of concentrated feed for the sows.

9. The sow feed as claimed in claim 8, wherein the preparation method of the sow feed in the feeding-restricted stage comprises the steps of:

1) pulverizing semen Maydis and soybean meal with 2.0 sieve;

2) crushing the concentrated sow feed through a 3.0 sieve sheet;

3) after 65% of corn, 15% of soybean meal and 20% of sow concentrate are mixed, the complete formula feed which reaches the national standard and meets the nutritional requirements of sows in the feeding-restricted stage is obtained.

10. The sow feed of claim 8, wherein the preparation method of the non-restricted feeding stage sow feed comprises the steps of:

1) pulverizing semen Maydis and soybean meal with 2.0 sieve;

2) crushing the concentrated sow feed through a 2.0 sieve sheet;

3) after 65% of corn, 15% of soybean meal and 20% of sow concentrate are mixed, the complete formula feed which reaches the national standard and meets the nutritional requirements of sows in the non-restricted feeding stage is obtained.

Technical Field

The invention belongs to the field of animal nutrition, feed formula, feed processing and pig farm production and application, and relates to a sow concentrate, a sow feed based on the sow concentrate and a preparation method of the sow feed.

Background

In the process of nutrition, feed formula, feed processing of sows and production management of pig farms, the nutrition configuration of the sow feed is complex (raw materials are complex) and the feed processing flow is fussy due to physiological and biochemical complexity and nutrition demand difference of sows at different periods and different stages, feed processing technological processes, production management complexity of the pig farms and the like. Different raw materials have inconsistent processing technologies, production is stopped for replacing sieve sheets, the production management operation of a pig farm is complicated (raw material purchasing, storage, processing and the like), and errors are easy to occur in the production process (a formula is complicated and the production flow is complicated). In addition, the temperature and humidity in different seasons can also cause the feed intake of sows to change, and endotoxin causes the infection of sows and secondary infection of sows and piglets due to environmental endotoxin, so that the nutrition taken by sows fluctuates greatly (too high or too low), and the sows have unbalanced nutrition and poor production benefit in a pig farm in the actual production process.

Because of different feeding management requirements of sows at different periods and different stages, the sows are divided into a feeding-limited stage (replacement gilts, pregnant sows and heavy sows) and a non-feeding-limited stage (lactating sows), the feeding-limited sows are generally crushed by adopting a 3.0-4.0 sieve sheet process, otherwise, the sows suffer from constipation, gastrointestinal ulcer, endotoxin damage caused by intestinal mucosa damage, clostridium reproduction and the like due to factors such as too small feed crushing granularity, too high feed-eating flow rate, lack of gastrointestinal peristalsis and the like; the non-restricted feeding sow is generally crushed by adopting a 1.5-2.0 sieve sheet process, otherwise, the nutrition absorption is insufficient, the protein digestion rate is reduced, the concentration of escherichia coli in excrement is extremely high, the content of indole and ammonia in ambient air is too high, and the like.

Because the sow feed is more in applied raw materials, purchasing and storing of different raw materials, processing technologies and formulas of the different raw materials have high complexity and the like, the error probability is increased in management and production.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide the sow concentrated feed and the preparation method thereof, which are used for uniformly treating complex sow feed and feed processing flows, so that the operation is simple, convenient, simplified and standardized, and the error probability in the production management process is reduced.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides a sow concentrate which comprises the following components in percentage by weight: 2-8% of beet pulp, 0-8% of rice bran, 0-6% of soybean peel, 0-4% of soybean meal, 0-2% of fish meal, 0-10% of puffed soybean, 0-1% of glucose, 0-1% of sucrose, 0-2% of puffed linseed oil powder and 4% of premix, wherein the sum of the weight percentages of the components is 20%.

Preferably, the premix comprises a replacement gilt premix, a pregnant sow premix, a heavy sow premix and a lactating sow premix, wherein:

the replacement sow premix comprises the following components in percentage by weight: 0.15% of choline chloride, 0.25% of lysine, 0.07% of methionine, 0.025% of phytase, 0.03% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.95% of stone powder, 0.71% of calcium hydrophosphate, 0.41% of sodium chloride, 0.015% of antioxidant, 0.01% of Nongmi, 0.01% of Eiwei XG10 enzyme, 0.5% of mildew adsorbent, 0.5% of zeolite powder and 0.27% of unite bran;

the pregnant sow premix comprises the following components in percentage by weight: 0.14% of choline chloride, 0.15% of lysine, 0.055% of methionine, 0.025% of phytase, 0.035% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.96% of stone powder, 0.72% of calcium hydrophosphate, 0.41% of sodium chloride, 0.015% of antioxidant, 0.01% of pesticide secret, 0.01% of Eiwei XG10 enzyme, 0.25% of Aichangbao, 0.5% of mildew adsorbent, 0.40% of zeolite powder and 0.22% of unite bran;

the heavy fetal sow premix comprises the following components in percentage by weight: 0.16% of choline chloride, 0.24% of lysine, 0.1% of methionine, 0.025% of phytase, 0.035% of composite vitamin of breeding pigs, 0.1% of composite mineral of breeding pigs, 0.97% of stone powder, 0.72% of calcium hydrophosphate, 0.43% of sodium chloride, 0.02% of antioxidant, 0.012% of Nongmi, 0.01% of EmuXG 10 enzyme, 0.3% of Aichangbao, 0.5% of mildew adsorbent, 0.278% of zeolite powder and 0.1% of unite bran;

the lactating sow premix comprises the following components in percentage by weight: 0.16% of choline chloride, 0.28% of lysine, 0.075% of methionine, 0.025% of phytase, 0.03% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.94% of stone powder, 0.72% of calcium hydrophosphate, 0.433% of sodium chloride, 0.02% of antioxidant, 0.012% of Nongmi, 0.012% of Eiwei XG10 enzyme, 0.3% of Aichangbao, 0.5% of mildew adsorbent and 0.393% of zeolite powder;

the compound vitamin for the breeding pigs comprises the following components in parts by weight: 10-150 parts of vitamin A, 310-50 parts of vitamin D, 100-600 parts of vitamin E, 33-30 parts of vitamin K, 11-10 parts of vitamin B, 25-60 parts of vitamin B, 62-20 parts of vitamin B, 121-20 parts of vitamin B, 2-20 parts of folic acid, 10-300 parts of biotin, 1-8 parts of nicotinamide and 3-30 parts of pantothenic acid; (ii) a

The pig compound mineral comprises the following components in parts by weight: 2-8 parts of copper, 15-40 parts of iron, 15-25 parts of zinc, 8-20 parts of manganese, 8-20 parts of iodine, 1-5 parts of selenium and 1-4 parts of chromium;

the agricultural secret is one or a combination of a plurality of agricultural secrets-F and agricultural secret-S;

the Everka XG10 enzyme is a non-starch polysaccharide enzyme preparation comprising xylanase and B-glucanase;

the Aichangbao contains one or more of medium chain glycerol fatty acid ester, acidifier, and organic iron.

In a preferred embodiment, the antioxidant is one or more of I-ascorbic acid, butylated hydroxytoluene, butylated hydroxyanisole, tocopherol and ethoxyquinoline.

Preferably, the mildew adsorbent is a composition of esterified glucomannan and antibacterial peptide, and the mass ratio of the esterified glucomannan to the antibacterial peptide is (1-5): 1 to 5.

More preferably, the rice bran is defatted rice bran.

More preferably, the content of the crude protein in the soybean meal is more than or equal to 43.0%.

More preferably, the content of crude protein in the fish meal is more than or equal to 65.0 percent.

More preferably, the content of crude fat in the puffed linseed oil powder is more than or equal to 32%.

Further, the invention provides a sow feed, which comprises a sow feed in a feeding-restricted stage (replacement gilt, pregnant sow and sow with heavy birth) and a sow feed in a non-feeding-restricted stage (lactating sow), wherein: the formula of the feed for the sows in the feeding-restricted stage and the formula of the feed for the sows in the non-feeding-restricted stage are 65 percent of corn, 15 percent of soybean meal and 20 percent of concentrated feed for the sows.

Furthermore, the preparation method of the sow feed in the feeding-restricted stage comprises the following steps:

1) pulverizing semen Maydis and soybean meal with 2.0 sieve;

2) crushing the concentrated sow feed through a 3.0 sieve sheet;

3) after 65% of corn, 15% of soybean meal and 20% of sow concentrate are mixed, the complete formula feed which reaches the national standard and meets the nutritional requirements of sows in the feeding-restricted stage is obtained.

Furthermore, the preparation method of the feed for the sows in the non-restricted feeding stage comprises the following steps:

1) pulverizing semen Maydis and soybean meal with 2.0 sieve;

2) crushing the concentrated sow feed through a 2.0 sieve sheet;

3) after 65% of corn, 15% of soybean meal and 20% of sow concentrate are mixed, the complete formula feed which reaches the national standard and meets the nutritional requirements of sows in the non-restricted feeding stage is obtained.

Soluble dietary fibers, rear intestinal fermentation fibers, composite mineral substances of the sows and the like are added into 20% of concentrated feed for the sows at different periods and different stages in different proportions, so that the purposes of promoting the limited-feeding sows (replacement sows, pregnant sows and heavy-fetus sows) to have sufficient gastrointestinal motility and avoiding water-salt metabolic disorder are achieved, constipation of the limited-feeding sows is avoided, and the uterine contractility of the sows is improved.

This application is through adding high soluble dietary fiber in the 20% sow concentrate in the restriction feed sow stage, and high proportion soluble fiber has extremely strong water absorption expansion rate, expands rapidly after restriction feed sow ingestion and drinking water, maintains gastrointestinal's filling, satisfies restriction feed sow's satiety, reduces stress that sow hunger brought and the high decibel noise that hunger caused.

According to the method, the crushing particle sizes of the raw materials in 20% of sow concentrates in different periods and different stages are controlled (coarse crushing particle sizes are adopted for feeding-limited sows, fine crushing particle sizes are adopted for non-feeding-limited sows), so that the flow of different sow concentrates in the subsequent production and processing process is simplified, only one standard uniform crushing sieve sheet is needed (production stop is not needed), and the production efficiency is improved by more than 20%; meanwhile, gastrointestinal ulcer and clostridium breeding of sows caused by small crushing granularity can be avoided.

The sow concentrated feed is simple and convenient to use, diversified in nutrition, capable of meeting the nutrition requirements of sows under the temperature and humidity conditions in different periods, different stages and different seasons, meanwhile, feed processing procedures are simplified, production efficiency is improved, the sow concentrated feed can be directly applied to pig farm production management, and production process complexity and error rate are reduced.

According to the method, the crushing granularity of 20% sow concentrated feed in different sow nutrition stages is controlled, the dietary fiber is added to enhance the gastrointestinal peristalsis of sows, the same screening piece technology is only needed no matter what sow feed (the later sow feed, the pregnant sow feed, the heavy sow feed and the lactating sow feed) is used, the screen pieces are not required to be replaced during production, the production efficiency is greatly improved, the labor capacity is reduced, and the operation is simple and rapid.

The invention has the beneficial technical effects that:

(1) the invention realizes the simplification of raw materials and the standardization of the formula (the formula is 65 percent of corn, 15 percent of soybean meal and 20 percent of sow concentrated feed, has consistency), and solves the problems of complicated purchasing process, complex processing technology, easy error production management and the like.

(2) The technology of the invention greatly improves the production efficiency in feed enterprises and pig farm production, reduces the number of different crushing processes for different raw materials and the number of screen pieces replaced without stopping production in the feed production and processing process, and improves the production efficiency by more than 20%.

(3) The technology of the invention solves the problems of accurate nutrition in the production management of different sows, avoids the harm of endotoxin and improves the microenvironment, wherein pathogenic microorganisms in the excrement can be reduced by more than 90 percent, and the concentration of ammonia gas in a piggery is reduced by more than 40 percent.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by those skilled in the art without any creative work based on the embodiments of the present invention belong to the protection scope of the present invention.

Example 1

The formula of the sow feed comprises the following components:

the preparation method of the sow feed (replacement gilt, pregnant sow and sow with heavy births) in the feeding-restricted stage comprises the following steps:

1) pulverizing semen Maydis and soybean meal with 2.0 sieve;

2) crushing the concentrated sow feed through a 3.0 sieve sheet;

3) after 65% of corn, 15% of soybean meal and 20% of sow concentrate are mixed, the complete formula feed which reaches the national standard and meets the nutritional requirements of sows in the feeding-restricted stage is obtained.

The preparation method of the feed (lactating sow) for the sows in the non-restricted feeding stage comprises the following steps:

1) pulverizing semen Maydis and soybean meal with 2.0 sieve;

2) crushing the concentrated sow feed through a 2.0 sieve sheet;

3) after 65% of corn, 15% of soybean meal and 20% of sow concentrate are mixed, the complete formula feed which reaches the national standard and meets the nutritional requirements of sows in the non-restricted feeding stage is obtained.

According to the invention, diversified raw material application is adopted for nutrition configuration, core nutritional elements of sows at different periods are configured into 20% sow concentrated feed, sow feed (post-prepared sow feed, pregnant sow feed, heavy sow feed and lactating sow feed) at any stage can be simply and conveniently configured into full-price compound feed meeting national standard and satisfying sow nutritional requirements only by adding 65% of corn, 15% of soybean meal and 20% of concentrated feed, purchasing management, raw material storage and processing technology and production management are very simple, convenient and fast, errors are not easy to make, the production efficiency can be improved, and the production efficiency is improved by more than 20%.

Example 2

The formula of the 20% sow concentrate comprises the following components:

in the embodiment, the replacement sow premix comprises the following components in percentage by weight: 0.15% of choline chloride, 0.25% of lysine, 0.07% of methionine, 0.025% of phytase, 0.03% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.95% of stone powder, 0.71% of calcium hydrophosphate, 0.41% of sodium chloride, 0.015% of antioxidant, 0.01% of miraculin-F, 0.01% of Eiwei XG10 enzyme, 0.5% of mildew adsorbent, 0.5% of zeolite powder and 0.27% of unite bran;

the premix for the pregnant sows comprises the following components in percentage by weight: 0.14% of choline chloride, 0.15% of lysine, 0.055% of methionine, 0.025% of phytase, 0.035% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.96% of stone powder, 0.72% of calcium hydrophosphate, 0.41% of sodium chloride, 0.015% of antioxidant, 0.01% of Nongmi-F, 0.01% of Eiwei XG10 enzyme, 0.25% of Aichangbao, 0.5% of mildew adsorbent, 0.40% of zeolite powder and 0.22% of unite bran;

the heavy fetal sow premix comprises the following components in percentage by weight: 0.16% of choline chloride, 0.24% of lysine, 0.1% of methionine, 0.025% of phytase, 0.035% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.97% of stone powder, 0.72% of calcium hydrophosphate, 0.43% of sodium chloride, 0.02% of antioxidant, 0.012% of miraculin-F, 0.01% of Eiwei XG10 enzyme, 0.3% of Aichangbao, 0.5% of mildew adsorbent, 0.278% of zeolite powder and 0.1% of unite bran;

the lactating sow premix comprises the following components in percentage by weight: 0.16% of choline chloride, 0.28% of lysine, 0.075% of methionine, 0.025% of phytase, 0.03% of compound vitamin of breeding pigs, 0.1% of compound mineral of breeding pigs, 0.94% of stone powder, 0.72% of calcium hydrophosphate, 0.433% of sodium chloride, 0.02% of antioxidant, 0.012% of miraculin-F, 0.012% of Eiwei XG10 enzyme, 0.3% of Aichangbao, 0.5% of mildew adsorbent and 0.393% of zeolite powder;

the compound vitamin for the breeding pigs comprises the following components in parts by weight: 68 parts of vitamin A, 312 parts of vitamin D, 500 parts of vitamin E, 327 parts of vitamin K, 16 parts of vitamin B, 222.5 parts of vitamin B, 611 parts of vitamin B, 126.5 parts of vitamin B, 105 parts of folic acid, 300 parts of biotin, 1.5 parts of nicotinamide and 13.5 parts of pantothenic acid;

the pig compound mineral comprises the following components in parts by weight: 6 parts of copper, 27 parts of iron, 20 parts of zinc, 12.5 parts of manganese, 12 parts of iodine, 2.5 parts of selenium and 2 parts of chromium;

the Everka XG10 enzyme is a non-starch polysaccharide enzyme preparation and comprises xylanase and B-glucanase (the mass ratio is 1: 1);

the Aichangbao is a composition of medium-chain glycerol fatty acid ester and organic iron, and the mass ratio of the medium-chain glycerol fatty acid ester to the organic iron is 2: 3.

The feed for the limited-feeding sows comprises a medium-high proportion of total fibers and a low proportion of fibers of non-limited-feeding animals, wherein 20% of sow concentrate of the feed for the limited-feeding sows is crushed by a 3.0 sieve sheet, and 20% of sow concentrate of the non-limited-feeding sows is crushed by a 2.0 sieve sheet.

Example 3

The nutritional indexes of the prepared complete batch are as follows:

the high-standard requirements of sow production nutrition and management are met through diversified nutrition, accurate nutrition, immune nutrition and anti-stress nutrition.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-described embodiments. Modifications and variations that may occur to those skilled in the art without departing from the spirit and scope of the invention are to be considered as within the scope of the invention.