Short-chain fatty acid composition for reducing abdominal fat deposition of broiler chickens and improving nutrient digestion and application of short-chain fatty acid composition

Abstract

The invention relates to the technical field of healthy breeding of broiler chickens, in particular to a short-chain fatty acid composition for reducing abdominal fat deposition of broiler chickens and improving nutrient digestion and application thereof.The short-chain fatty acid composition is formed by compounding acetic acid, propionic acid and butyric acid according to the molar ratio of (6.1-6.2): (1.3-1.32): (1.65-1.68), and the short-chain fatty acid composition and feed are mixed together to feed the broiler chickens when the short-chain fatty acid composition is applied. The short-chain fatty acid composition disclosed by the invention can obviously reduce liver fat infiltration of broilers, reduce liver fat deposition, reduce the area of abdominal fat adipocytes and further reduce abdominal fat deposition of the broilers. According to the short-chain fatty acid composition disclosed by the invention, the apparent digestibility of crude protein and crude fat of the broiler chicken is remarkably improved, the intestinal form is improved, nutrient digestion is improved, and the health of lipid metabolism of an organism is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of healthy broiler breeding, and more specifically, relates to a short-chain fatty acid composition capable of reducing abdominal fat deposition in broilers and improving nutrient digestion, and an application thereof. Background Art

[0002] The current breeding pursuit of rapid growth has made the problem of excessive deposition of abdominal fat and subcutaneous fat in broiler chickens more prominent. Studies have found that excessive deposition of body fat damages the quality of chicken, increases slaughter costs, and causes serious economic losses to the broiler industry. Excessive deposition of abdominal fat can also cause fat to accumulate in the liver, induce fatty liver, and increase the incidence of ascites and sudden death in broiler chickens. In addition, because the economic value of chicken abdominal fat is extremely low, it is often discarded during slaughtering and processing, which can easily cause environmental pollution. Therefore, the research and development of regulatory measures to reduce abdominal fat deposition is of great significance to ensure the healthy development of the broiler industry.

[0003] Short-chain fatty acids are the main metabolites of intestinal microorganisms. The report pointed out that acetic acid can reduce liver fat deposition in mice and improve glucose tolerance; propionic acid can reduce the energy intake of mice, thereby reducing abdominal fat deposition; butyric acid can provide energy for colon cells and activate intestinal gluconeogenesis, which is beneficial to the body's glucose and energy homeostasis. Studies on mice, pigs and humans have found that exogenous administration of short-chain fatty acids can reduce body fat deposition. Previous studies have also found that short-chain fatty acids can significantly improve lipid metabolism in piglets through gavage. Studies have found that butyrate is also a stimulator of intestinal epithelial growth in broilers and a regulator of gastrointestinal microbial composition and activity, and sodium butyrate can promote the proliferation of intestinal epithelial cells, maintain intestinal mucosal morphology, improve intestinal health, and improve the growth performance of broilers. In addition, the addition of butyric acid glyceride to the diet can reduce abdominal fat deposition in broilers, and sodium butyrate has also been shown to reduce body fat deposition in broilers.

[0004] The above studies show that the use of some short-chain fatty acids alone can effectively reduce fat deposition in some animals; however, it cannot meet the needs of improving nutrient digestion. Summary of the invention

[0005] The purpose of the present invention is to provide a short-chain fatty acid composition and application thereof for reducing abdominal fat deposition in broilers and improving nutrient digestion.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a short-chain fatty acid composition for reducing abdominal fat deposition in broilers and improving nutrient digestion, which is compounded by acetic acid, propionic acid and butyric acid in a molar ratio of 6.1-6.2:1.3-1.32:1.65-1.68.

[0008] The short-chain fatty acid composition of the present invention is compounded by acetic acid, propionic acid and butyric acid according to the molar ratio of 6.1-6.2:1.3-1.32:1.65-1.68, which can improve the intestinal morphology by increasing the height of the intestinal villi of broilers and reducing the depth of the crypts, thereby improving the apparent digestibility of crude protein and crude fat of broilers. Compared with the single use of the prior art, the present invention first discovered that the short-chain fatty acid composition can reduce the use of protein and fat raw materials in broiler feed, thereby reducing costs, and providing a basis for the scientific and reasonable application of feed in production practice. It can also reduce the abdominal fat rate of broilers and inhibit abdominal fat deposition by reducing the area of ​​abdominal fat adipocytes and liver fat deposition, thereby expanding the application of short-chain fatty acids in the healthy breeding of broilers.

[0009] In a second aspect, the present invention provides any of the following uses of the short-chain fatty acid composition for reducing abdominal fat deposition and improving nutrient digestion in broilers:

[0010] 1) for preparing a product for reducing lipid deposition in broiler chickens; and

[0011] 2) Used to prepare products for improving nutrient digestion in broiler chickens.

[0012] Furthermore, the lipid deposition includes abdominal fat deposition and liver fat deposition.

[0013] Furthermore, the nutrients include crude fat and crude protein.

[0014] Furthermore, the broiler chickens are 22 to 42 days old.

[0015] Furthermore, the product is a preparation to be taken after being mixed with feed, and the preparation uses water as a solvent.

[0016] Furthermore, the concentrations of acetic acid, propionic acid and butyric acid in the preparation are 6.1-6.2 mMol / L, 1.3-1.32 mMol / L and 1.65-1.68 mMol / L, respectively. The amount of the preparation to be administered to broilers is calculated based on the estimated weight of the broilers on the day of administration, and the daily volume of the preparation administered is 14-16 mL / kg.

[0017] The present invention has the following beneficial effects:

[0018] The present invention significantly reduces the area of ​​abdominal fat cells and reduces abdominal fat deposition in broilers by combining acetic acid, propionic acid and butyric acid. At the same time, the apparent digestibility of crude protein and crude fat in broilers is improved. The present invention provides a new technical approach for alleviating excessive abdominal fat deposition in broilers and improving feed conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1The figure shows the effect of short-chain fatty acid composition S1 on the morphological structure of broiler small intestine, wherein A is the HE staining image of the duodenum of the control group (20X), B is the HE staining image of the duodenum of the short-chain fatty acid composition S1 group (20X), C is the HE staining image of the jejunum of the control group (20X), D is the HE staining image of the jejunum of the short-chain fatty acid composition S1 group (20X), E is the HE staining image of the ileum of the control group (20X), and F is the HE staining image of the ileum of the short-chain fatty acid composition S1 group (20X).

[0020] Figure 2 The figure shows the effect of short-chain fatty acid composition on the area of ​​abdominal fat adipocytes in broiler chickens, wherein A is the statistical graph of adipocyte area, B is the HE staining graph of the control group, and C is the HE staining graph of the short-chain fatty acid composition S1 group (40X).

[0021] Figure 3 The figure shows the effect of short-chain fatty acid composition S1 on the area of ​​abdominal fat adipocytes in broiler chickens, wherein A is the statistical graph of adipocyte area, B is the HE staining graph of the control group, and C is the HE staining graph of the short-chain fatty acid composition S1 group (20X).

[0022] Figure 4 The figure shows the effect of short-chain fatty acid composition S1 on the positive rate of fat droplets in abdominal fat of broiler chickens, wherein A is the statistical graph of the positive rate of fat droplets, B is the oil red staining graph of the control group, and C is the oil red staining graph of the short-chain fatty acid composition S1 group (20X).

[0023] Figure 5 The figure shows the effect of short-chain fatty acid composition S1 on the lipid droplet positivity rate in broiler livers, wherein A is a statistical graph of lipid droplet positivity rate, B is a HE staining graph of the control group, and C is a HE staining graph of the short-chain fatty acid composition S1 group (40X).

[0024] Figure 6 The figure shows the effect of short-chain fatty acid composition S1 on the lipid droplet positivity rate in broiler livers, wherein A is a statistical graph of lipid droplet positivity rate, B is a HE staining graph of the control group, and C is a HE staining graph of the short-chain fatty acid composition S1 group (20X). DETAILED DESCRIPTION

[0025] The present invention is described in detail with respect to specific examples below, but it should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources.

[0026] The three short-chain fatty acids provided by the present invention are commercially available. By combining the three in different molar ratios, the abdominal fat rate of broilers can be reduced, the abdominal fat and liver lipid deposition can be inhibited, and the area of ​​abdominal fat adipocytes can be reduced; in addition, the height of the intestinal villi of broilers can be increased, the depth of the crypts can be reduced, and the intestinal morphology can be improved; at the same time, the apparent metabolic rate of crude protein and crude fat of broilers can be increased, and the feed-to-meat ratio can be reduced.

[0027] In the present invention, the composition proportions and different concentrations of different short-chain fatty acid compositions are as follows: S1 (acetic acid 6.14 mMol / L, propionic acid 1.31 mMol / L, butyric acid 1.67 mMol / L), S2 (acetic acid 12.28 mMol / L, propionic acid 2.62 mMol / L, butyric acid 3.35 mMol / L), S3 (acetic acid 18.42 mMol / L, propionic acid 3.93 mMol / L, butyric acid 5.02 mMol / L).

[0028] The following is a description of specific examples, and the raw materials used in the examples can be obtained commercially.

[0029] Example 1

[0030] The purpose of this experiment was to explore the effects of short-chain fatty acid compositions of different concentrations on lipid metabolism, growth performance and apparent metabolic rate in broiler chickens. A total of 192 healthy broiler chickens of similar body weight at 21 days of age were selected and randomly divided into 4 treatment groups, with 6 replicates in each group and 8 chickens in each replicate. The control group was fed with a basic diet (composition as shown in Table 1) and mixed with normal saline according to the estimated weight of each chicken (referenced to the weight of broilers at the corresponding age) × 15mL / kg per day, and the experimental group was fed with a basic diet and mixed with short-chain fatty acid compositions of different concentrations according to the estimated weight of each chicken × 15mL / kg per day; they were S1 (acetic acid 6.14mMol / L, propionic acid 1.31mMol / L, butyric acid 1.67mMol / L), S2 (acetic acid 12.28mMol / L, propionic acid 2.62mMol / L, butyric acid 3.35mMol / L) and S3 (acetic acid 18.42mMol / L, propionic acid 3.93mMol / L, butyric acid 5.02mMol / L) short-chain fatty acid compositions. The diet was prepared according to NRC (1994) (Table 1), and the experimental period was 21 days. The feed intake and weight gain of the chickens were recorded during the experiment.

[0031] Table 1 Basic feed composition and nutritional level

[0032]

[0033]

[0034] Note: 1The mineral premix provided per kg feed: 8.00 mg Cu, 80.00 mg Fe, 40.00 mg Zn, 60.00 mg Mn, 0.35 mg I, 0.15 mg Se; 2 Vitamin premix provides per kg feed: 2000.00IU vitamin A, 300.00IU vitamin D3, 10.00IU vitamin E, 0.50mg vitamin K3, 2.00mg vitamin B1, 8.00mg vitamin B2, 4.00mg vitamin B6, 0.01mg vitamin B 12 , 0.20mg biotin, 1.00mg folic acid, 35.00mg niacin, 10.00mg pantothenic acid; 3 The nutrient levels are calculated values. “ / ” means that the item is not included.

[0035] Table 2 Effects of different concentrations of short-chain fatty acid compositions on the growth performance of broilers

[0036] project Control group S1 Group S2 Group S3 Group Initial body weight (kg) 0.89±0.03 0.89±0.02 0.89±0.03 0.90±0.01 Final weight(kg) 2.61±0.11 2.63±0.07 2.61±0.10 2.65±0.05 Average daily feed intake (g) 145.81±2.38 146.89±3.15 146.94±1.57 149.79±2.41 Average daily weight gain (g) 81.80±1.52 82.74±3.22 81.76±2.82 83.49±1.88 Feed to meat ratio (%) 1.78±0.04 1.77±0.05 1.80±0.02 1.80±0.02

[0037] As shown in Table 2, although the administration of short-chain fatty acid compositions of different concentrations had no significant effect on the final weight, average daily feed intake and average of broilers, the broilers that were gavaged with S1 concentration (acetic acid 6.14mMol / L, propionic acid 1.31mMol / L, butyric acid 1.67mMol / L) had the lowest feed-to-weight ratio.

[0038] Example 2

[0039] The determination of apparent metabolic rate is very important in broiler breeding, which can reflect the degree of digestion of feed nutrients. By detecting the corresponding indicators of apparent metabolic rate, the digestion and utilization of feed by broilers can be understood. According to Example 1, a broiler breeding experiment was carried out, 500g of feed sample was collected by quartering method, crushed and passed through a 40-mesh sieve, and stored at -20°C for standby use; feces samples were collected by half-feces collection method 3 days before the end of the experiment; dry matter (GB / T 6435-2014), crude fat (GB / T 6433-2006 / ISO 6492:1999), crude protein (GB / T 6432-2018), crude ash (GB / T 6438-2007 / ISO 5984:2002) and hydrochloric acid insoluble ash (GB / T 24372-2009 / ISO 5985:2002) in feces and feed were determined respectively.

[0040] The dry matter detection steps include: Sampling: Collect fresh feces samples from morning, mid-term and evening broilers according to the half-manure collection method from the 19th to the 21st day of the test, and remove impurities such as feed, feathers, and dander. Add 10% sulfuric acid to fix nitrogen according to 10% of the weight of fresh feces, 2 to 3 drops of toluene for preservation, mix well, and store in a -20℃ refrigerator. Pretreatment: After 3 days of collection, mix the feces sample, take 200 to 300g of samples, and dry them in a 65℃ oven for 72h. Crush the feces sample and use it for rough nutrient analysis after passing through a 40-mesh sieve. Drying: Put the pretreated feces sample into an oven and dry it at 103±2℃ until the sample reaches a constant weight. Weighing: After drying, weigh the sample and record its mass. Calculation: Calculate the dry matter content of the sample based on the mass difference before and after drying.

[0041] Crude ash testing includes: Sampling and pretreatment: Collect and pretreat fecal samples as in dry matter testing. Burning: Place the pretreated sample in a muffle furnace and burn it at 550°C until the sample reaches a constant weight. Cooling and weighing: After burning, take out the sample and cool it to room temperature before weighing it. Calculation: Calculate the crude ash content of the sample based on the mass difference before and after burning.

[0042] Crude fat detection includes: Sampling and pretreatment: Collect and pretreat samples. Extraction: Soxhlet extraction is used to extract crude fat from samples. Weighing: Weigh the filter paper bag containing the sample before and after extraction. Calculation: Calculate the crude fat content of the sample based on the mass of the filter paper bag containing the sample and the original sample before and after extraction.

[0043] Crude protein testing includes: Sampling and pretreatment: Collect and pretreat samples. Digestion: Mix the pretreated samples with sulfuric acid for digestion. Distillation and titration: After digestion, the nitrogen content in the sample is determined using the Kjeldahl method. Then, the crude protein content of the sample is calculated based on the nitrogen content and the conversion factor (6.25).

[0044] The hydrochloric acid insoluble ash test includes: transferring the ash obtained after calcination into a beaker with dilute hydrochloric acid, heating and boiling in an electric furnace for 15 minutes, filtering with filter paper without ash while hot, and washing the filter paper and filter residue with hot water until the washing liquid is not acidic. Place the filter paper with filter residue in a crucible at 103±2℃ for 2h, then calcine in a muffle furnace at 550℃ for 30min, and weigh. Calculation: Calculate the hydrochloric acid insoluble ash content of the sample based on the mass of the crucible and ash before calcination and the mass of the crucible and acid-insoluble ash after calcination.

[0045] Table 3 Effects of different concentrations of short-chain fatty acid compositions on the apparent metabolic rate of nutrients in broilers

[0046] project Control group S1 Group S2 Group S3 Group Dry matter (%) 67.63±3.22 69.06±2.34 68.56±1.58 67.32±3.12 Crude ash (%) 14.08±1.28 19.50±1.11 17.92±2.41 12.96±2.01 Crude fat (%) <![CDATA[70.94 b ±3.84]]> <![CDATA[76.98 a ±2.07]]> <![CDATA[74.93 a ±3.64]]> <![CDATA[74.30 ab ±1.92]]> Crude protein (%) <![CDATA[63.59 ab ±3.24]]> <![CDATA[67.12 a ±1.58]]> <![CDATA[65.75 a ±2.37]]> <![CDATA[62.02 b ±3.61]]>

[0047] Note: Data in the same row with different letters on their shoulders indicate significant differences (P<0.05), and 0.05≤P<0.10 is considered to be a trend.

[0048] As shown in Table 3, the administration of short-chain fatty acid compositions of different concentrations significantly affected the apparent metabolic rate of nutrients in broiler chickens (P<0.05). The apparent metabolic rates of crude protein and crude fat in broiler chickens administered with S1 concentration were the highest and significantly higher than those in the control group (P<0.01). The apparent metabolic rates of dry matter and crude ash in broiler chickens administered with S1 concentration were also the highest.

[0049] Example 3

[0050] It is of great significance to measure the organ index of broiler chickens in broiler breeding, and the organ index is an important indicator for evaluating the health status of broilers. According to Example 1, a broiler breeding experiment was carried out. At the end of the experiment, chickens with a weight close to the average were selected for each repetition to be slaughtered to obtain organs (heart, liver, spleen, thymus, bursa of Fabricius, kidney) and abdominal fat tissue. The corresponding organ index was calculated according to the organ weight and the weight of the slaughtered broiler chicken by weighing.

[0051] Table 4 Effects of different concentrations of short-chain fatty acid compositions on broiler organ indexes

[0052]

[0053]

[0054] As shown in Table 4, the administration of short-chain fatty acid compositions of different concentrations had no significant effect on the organ indexes of broiler chickens (heart, liver, spleen, thymus, bursa of Fabricius, and kidney), but the abdominal fat rate of broiler chickens administered with S1 concentration tended to be lower than that of the control group (P<0.10).

[0055] Example 4

[0056] It is of great significance to measure the height of intestinal villi and the depth of crypts in broiler breeding. The intestinal morphology is an important basis for evaluating the digestion and absorption capacity of nutrient in the intestine of broilers. According to Example 1, a broiler breeding experiment was carried out. At the end of the experiment, chickens with a weight close to the average were selected for each repetition and slaughtered to obtain the small intestine segments (duodenum, jejunum and ileum). The small intestine tissue fixed with 4% paraformaldehyde was taken out, and paraffin sections were made according to the steps of trimming-rinsing-dehydration-transparent-embedding-slicing-spreading-staining (hematoxylin-eosin staining, HE)-sealing. After the sections were made, the morphology of the small intestinal villi was observed under a microscope (40 times), and 12 complete intestinal villi were randomly selected for each section. The villus height (Villusheight, VH) and crypt depth (Crypt depth, CD) were measured by VistarImage X64 software, and the ratio of villus height to crypt depth (VH / CD) was calculated.

[0057] Table 5 Effects of different concentrations of short-chain fatty acid compositions on the morphological structure of the small intestine of broiler chickens

[0058]

[0059]

[0060] From Table 5 and Figure 1 It can be seen that although the short-chain fatty acid composition at S1 concentration had no significant effect on the morphological structure of the duodenum, jejunum and ileum of broiler chickens, the villus height and villus crypt ratio of the duodenum, jejunum and ileum were numerically higher than those of the control group, and the crypt depth of the duodenum, jejunum and ileum was lower than that of the control group.

[0061] Example 5

[0062] The determination of abdominal fat and liver fat deposition in broiler breeding is of great significance for evaluating the health of the body. The amount of abdominal fat deposition and liver fat infiltration have a great impact on the health of broilers. According to Example 1, a broiler breeding experiment was carried out. At the end of the experiment, chickens with a weight close to the average were selected for slaughter to obtain abdominal fat and liver. The abdominal fat was stained with HE, and the method was referred to Example 4 to measure the area of ​​abdominal fat cells in the broiler; the liver and abdominal fat were stained with Oil Red O for analysis; 3 slices were randomly selected from each group for each slice to be photographed at 200 times and 400 times the field of view, and the background light of each photo was ensured to be consistent when taking pictures. Image-Pro Plus6.0 software was used to count the area of ​​abdominal fat cells, and the liver and fat positive expression areas were selected. The positive rate was counted according to the positive area ratio and the positive surface density (degree of infiltration).

[0063] Depend on Figure 2 and Figure 3 It can be seen that HE staining was used to take photos and measure at 200 and 400 times the field of view, and the short-chain fatty acid composition with S1 concentration significantly reduced the abdominal fat area of ​​broiler chickens (P<0.05). Figure 4 It can be seen that the short-chain fatty acid composition with S1 concentration significantly reduced abdominal fat deposition in broilers under the 200-fold field of view of oil red staining (P<0.05); Figure 5 and Figure 6 The results showed that the short-chain fatty acid composition at S1 concentration significantly reduced liver fat infiltration and liver fat deposition in broiler chickens at 200 and 400 times the field of view (P<0.05), indicating that the short-chain fatty acid composition at S1 concentration can effectively promote the healthy lipid metabolism of broiler chickens.

[0064] It should be noted that when the claims of the present invention involve numerical ranges, it should be understood that the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. In order to avoid redundancy, the present invention describes a preferred embodiment.

[0065] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A short-chain fatty acid composition for reducing abdominal fat deposition in broilers and improving nutrient digestion, characterized in that: The acetic acid, propionic acid and butyric acid are compounded according to the molar ratio of 6.1-6.2:1.3-1.32:1.65-1.68, and the nutrients include crude fat and crude protein.

2. The following application of the short-chain fatty acid composition for reducing abdominal fat deposition and improving nutrient digestion in broilers according to claim 1: 1) for preparing a product for reducing lipid deposition in broiler chickens; and 2) Used to prepare products for improving nutrient digestion in broiler chickens.

3. The use according to claim 2, characterized in that: The lipid deposition includes abdominal fat deposition and liver fat deposition.

4. The use according to claim 2, characterized in that: The nutrients include crude fat and crude protein.

5. The use according to claim 2, characterized in that: The product is a preparation to be taken after being mixed with feed.

6. The use according to claim 5, characterized in that: The preparation uses water as solvent.

7. The use according to claim 5, characterized in that: The concentrations of acetic acid, propionic acid and butyric acid in the preparation are 6.1-6.2 mMol / L, 1.3-1.32 mMol / L and 1.65-1.68 mMol / L, respectively.

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