A short-chain fatty acid composition for reducing abdominal fat deposition in broilers and improving nutrient digestion and its application

Abstract

The present invention relates to the technical field of healthy broiler breeding, and particularly relates to a short-chain fatty acid composition for reducing abdominal fat deposition in broilers and improving nutrient digestion, and its application. The short-chain fatty acid composition of the present invention is compounded by acetic acid, propionic acid and butyric acid according to a molar ratio of 6.1-6.2:1.3-1.32:1.65-1.68, and is fed to broilers by mixing with feed during application. The short-chain fatty acid composition of the present invention can significantly reduce liver fat infiltration in broilers, reduce liver fat deposition, reduce the area of abdominal fat adipocytes, and thus reduce abdominal fat deposition in broilers. The short-chain fatty acid composition of the present invention significantly improves the apparent digestibility of crude protein and crude fat in broilers, improves intestinal morphology, and improves nutrient digestion, which is beneficial to the health of body lipid metabolism.

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 described in the present invention 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. It can improve the intestinal morphology of broiler chickens by increasing the intestinal villus height and decreasing the crypt depth, and improve the apparent digestibility of crude protein and crude fat in broiler chickens. Compared with the single use in the prior art, the present invention first discovers that the short-chain fatty acid composition can not only reduce the use of protein and fat raw materials in broiler chicken diets, thereby reducing costs, but also provides a basis for the scientific and reasonable application of feed in production practice. It can also reduce the abdominal fat rate of broiler chickens and inhibit abdominal fat deposition by reducing the abdominal fat cell area and liver fat deposition, expanding the application of short-chain fatty acids in the healthy breeding of broiler chickens.

[0009] Second, the present invention provides any one of the following applications of the short-chain fatty acid composition for reducing abdominal fat deposition and improving nutrient digestion in broiler chickens:

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

[0011] 2) For preparing a product 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 22-42 days old.

[0015] Furthermore, the product is a preparation taken after being mixed with the 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 in sequence. The amount of the preparation mixed and taken by broiler chickens is calculated according to the estimated weight of the broiler chickens on the same day, and the volume of the preparation mixed and taken every day is 14-16 mL / kg.

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

[0018] By combining acetic acid, propionic acid, and butyric acid, the present invention significantly reduces the abdominal fat cell area and decreases the abdominal fat deposition in broiler chickens. At the same time, it improves the apparent digestibility of crude protein and crude fat in broiler chickens. The present invention provides a new technical approach for alleviating excessive abdominal fat deposition and improving feed conversion efficiency in broiler chickens. Description of the Drawings

[0019] Figure 1Effect of orally administered short-chain fatty acid composition S1 on the small intestinal morphological structure of broilers. Among them, A is the HE staining diagram of the duodenum of the control group (20X), B is the HE staining diagram of the duodenum of the short-chain fatty acid composition S1 group (20X), C is the HE staining diagram of the jejunum of the control group (20X), D is the HE staining diagram of the jejunum of the short-chain fatty acid composition S1 group (20X), E is the HE staining diagram of the ileum of the control group (20X), and F is the HE staining diagram of the ileum of the short-chain fatty acid composition S1 group (20X).

[0020] Figure 2 Effect of orally administered short-chain fatty acid composition on the adipocyte area of broiler abdominal fat. Among them, A is the statistical chart of adipocyte area, B is the HE staining diagram of the control group, and C is the HE staining diagram of the short-chain fatty acid composition S1 group (40X).

[0021] Figure 3 Effect of orally administered short-chain fatty acid composition S1 on the adipocyte area of broiler abdominal fat. Among them, A is the statistical chart of adipocyte area, B is the HE staining diagram of the control group, and C is the HE staining diagram of the short-chain fatty acid composition S1 group (20X).

[0022] Figure 4 Effect of orally administered short-chain fatty acid composition S1 on the positive rate of lipid droplets in broiler abdominal fat. Among them, A is the statistical chart of the positive rate of lipid droplets, B is the oil red staining diagram of the control group, and C is the oil red staining diagram of the short-chain fatty acid composition S1 group (20X).

[0023] Figure 5 Effect of orally administered short-chain fatty acid composition S1 on the positive rate of lipid droplets in broiler liver. Among them, A is the statistical chart of the positive rate of lipid droplets, B is the HE staining diagram of the control group, and C is the HE staining diagram of the short-chain fatty acid composition S1 group (40X).

[0024] Figure 6 Effect of orally administered short-chain fatty acid composition S1 on the positive rate of lipid droplets in broiler liver. Among them, A is the statistical chart of the positive rate of lipid droplets, B is the HE staining diagram of the control group, and C is the HE staining diagram of the short-chain fatty acid composition S1 group (20X). Detailed implementation mode

[0025] The present invention will be described in detail below with reference to specific embodiments, but it should not be construed as a limitation of the present invention. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art. The materials, reagents, etc. used in the following embodiments can be obtained from commercial channels unless otherwise specified.

[0026] The three short-chain fatty acids provided by the present invention are commercially available. By combining them in different molar ratios, it can reduce the abdominal fat rate of broilers, inhibit abdominal fat and liver lipid deposition, and reduce the area of abdominal fat adipocytes; in addition, it can increase the intestinal villus height of broilers, reduce the crypt depth, and improve the intestinal morphology; at the same time, it can increase the apparent metabolic rates of crude protein and crude fat in broilers and reduce the feed-to-gain ratio.

[0027] In the present invention, different short-chain fatty acid compositions, their composition ratios and different concentrations 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 illustrated by specific examples, and all raw materials used in the examples can be obtained through commercial purchase.

[0029] Example 1

[0030] This experiment aimed to explore the effects of mixing and administering different concentrations of short-chain fatty acid compositions on lipid metabolism, growth performance and apparent metabolic rate of broilers. 192 healthy broilers with similar body weights at 21 days of age were selected and randomly divided into 4 treatment groups, with 6 replicates in each group and 8 broilers in each replicate. The control group was fed a basal diet (the composition is shown in Table 1) and mixed and administered normal saline at 15 mL / kg of the estimated body weight of each chicken (referring to the body weight of broilers at the corresponding age), and the experimental groups were fed the basal diet and mixed and administered different concentrations of short-chain fatty acid compositions at 15 mL / kg of the estimated body weight of each chicken; namely, the short-chain fatty acid compositions of 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) and S3 (acetic acid 18.42 mMol / L, propionic acid 3.93 mMol / L, butyric acid 5.02 mMol / L). The diet was formulated according to NRC (1994) (Table 1), and the experimental period was 21 days. The feed intake and weight gain of the chickens during the experimental period were recorded.

[0031] Table 1 Composition and nutrient levels of the basal diet

[0032]

[0033]

[0034] Note: 1The mineral premix provides per kilogram of 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 The vitamin premix provides per kilogram of feed: 2000.00 IU vitamin A, 300.00 IU vitamin D3, 10.00 IU vitamin E, 0.50 mg vitamin K3, 2.00 mg vitamin B1, 8.00 mg vitamin B2, 4.00 mg vitamin B6, 0.01 mg vitamin B 12 , 0.20 mg biotin, 1.00 mg folic acid, 35.00 mg niacin, 10.00 mg pantothenic acid; 3 The nutrient levels are calculated values. " / " indicates the item is not included.

[0035] Table 2 Effects of Different Concentrations of Short-chain Fatty Acid Combinations Administered Orally on the Growth Performance of Broiler Chickens

[0036] Item Control Group Group S1 Group S2 Group S3 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 Gain (g) 81.80±1.52 82.74±3.22 81.76±2.82 83.49±1.88 Feed Conversion Ratio (%) 1.78±0.04 1.77±0.05 1.80±0.02 1.80±0.02

[0037] As can be seen from Table 2, although the administration of different concentrations of short-chain fatty acid combinations orally had no significant effect on the final weight, average daily feed intake, and average of broiler chickens, the feed-to-gain ratio of broiler chickens administered with S1 concentration (acetic acid 6.14 mMol / L, propionic acid 1.31 mMol / L, butyric acid 1.67 mMol / L) was the lowest.

[0038] Example 2

[0039] The determination of apparent metabolic rate is very important in broiler chicken breeding, which can reflect the digestion degree of feed nutrients. By detecting the corresponding indexes of apparent metabolic rate, the digestion and utilization of feed by broiler chickens can be understood. Conduct a broiler chicken breeding experiment according to Example 1, collect 500 g of feed samples by the quartering method, crush and sieve through a 40-mesh sieve, and store at -20 °C for later use; collect fecal samples by the semi-fecal collection method 3 days before the end of the experiment; determine the 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 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] Item Control Group Group S1 Group S2 Group S3 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: Different superscript letters among data in the same row indicate significant differences (P<0.05), and 0.05≤P<0.10 is regarded as a trend.

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

[0049] Example 3

[0050] It is of great significance to measure the organ indices of broilers during broiler breeding. 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 close to the average body weight were selected from each replicate for slaughter to obtain organs (heart, liver, spleen, thymus, bursa of Fabricius, kidney) and abdominal fat tissue. And through weighing, the corresponding organ indices were calculated according to the organ weights and the body weights of the slaughtered broilers.

[0051] Table 4 Effects of administering different concentrations of short-chain fatty acid compositions on the organ indices of broilers

[0052]

[0053]

[0054] As can be seen from Table 4, administering different concentrations of short-chain fatty acid compositions had no significant effect on the organ indices (heart, liver, spleen, thymus, bursa of Fabricius, kidney) of broilers, but there was a trend that the abdominal fat rate of broilers administered with S1 concentration was lower than that of the control group (P<0.10).

[0055] Example 4

[0056] It is of great significance to measure the intestinal villus height and crypt depth during broiler breeding. The intestinal morphological structure is an important basis for evaluating the ability of the broiler intestine to digest and absorb nutrients. According to Example 1, a broiler breeding experiment was carried out. At the end of the experiment, chickens close to the average body weight were selected from each replicate for slaughter to obtain each intestinal segment of the small intestine (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 - dehydrating - clearing - embedding - sectioning - spreading - staining (hematoxylin-eosin staining, HE) - covering. After the section preparation was completed, the morphology of the small intestinal villi was observed under a microscope (40 times). For each section, 12 complete intestinal villi were randomly selected, and the villus height (Villusheight, VH) and crypt depth (Crypt depth, CD) were measured through 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 Combinations Administered Orally on the Intestinal Morphology of Broiler Chickens

[0058]

[0059]

[0060] As shown in Table 5 and Figure 1 it can be seen that although the administration of the short-chain fatty acid combination at S1 concentration had no significant effect on the intestinal morphology of the duodenum, jejunum, and ileum of broiler chickens, numerically, the villus height and villus-crypt ratio of the duodenum, jejunum, and ileum were 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 chickens 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 broiler chickens. According to Example 1, a broiler chicken breeding experiment was carried out. At the end of the experiment, chickens close to the average body weight were selected from each replicate 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 broiler chickens; the liver and abdominal fat were analyzed by Oil Red O staining; 3 random fields of view were selected from each section in each group at 200-fold and 400-fold magnifications for photographing, and the background light of each photograph was ensured to be consistent during photographing. Using Image-Pro Plus 6.0 software, the area of abdominal fat cells was statistically analyzed, and the positive expression area of the liver and fat was selected. The positive rate was statistically analyzed according to the proportion of the positive area and the positive surface density (infiltration degree).

[0063] From Figure 2 and Figure 3 it can be seen that by photographing and measuring at 200-fold and 400-fold magnifications with HE staining, the administration of the short-chain fatty acid combination at S1 concentration significantly reduced the abdominal fat area of broiler chickens (P<0.05). From Figure 4 it can be seen that under the 200-fold magnification of Oil Red staining, the administration of the short-chain fatty acid combination at S1 concentration significantly reduced the abdominal fat deposition of broiler chickens (P<0.05); similarly, from Figure 5 and Figure 6 it was obtained that the administration of the short-chain fatty acid combination at S1 concentration significantly reduced the liver fat infiltration and liver fat deposition of broiler chickens under 200-fold and 400-fold magnifications (P<0.05). It indicates that the administration of the short-chain fatty acid combination at S1 concentration can effectively promote the lipid metabolism health of broiler chickens.

[0064] It should be noted that when the numerical range is involved in the claims of the present invention, it should be understood that any value between the two endpoints of each numerical range and the two endpoints can be selected. To prevent unnecessary repetition, preferred embodiments of the present invention are described.

[0065] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made by those skilled in the art once they learn of the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as 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 equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. Use of a short-chain fatty acid composition in preparing a product for reducing lipid deposition in broilers and improving nutrient digestion in broilers, characterized in that: The short-chain fatty acid composition is compounded by acetic acid, propionic acid and butyric acid according to a molar ratio of 6.1-6.2:1.3-1.32:1.65-1.68, the nutrients include crude fat and crude protein, and the concentrations of acetic acid, propionic acid and butyric acid in the product are 6.1-6.2 mmol / L, 1.3-1.32 mmol / L and 1.65-1.68 mmol / L, respectively.

2. The use according to claim 1, characterized in that: The lipid deposition includes abdominal fat deposition and liver fat deposition.

3. The use according to claim 1, characterized in that: The product is a preparation to be taken after being mixed with feed.

4. The use according to claim 3, characterized in that: The preparation uses water as solvent.

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