Optimized live pig low-protein daily ration capable of balancing nitrogen

Abstract

The invention belongs to the field of animal nutrition and feed, and particularly discloses a live pig low-protein daily ration for balancing energy nitrogen by optimizing starch composition, which comprises the following components: corn, corn substitute, barley, soybean meal, soybean oil, bran, calcium hydrophosphate, mountain flour, lysine hydrochloride, methionine, threonine, tryptophan and premix. The invention further discloses a preparation method of the low-protein daily ration for the live pigs. The starch composition of the feed is optimized, synchronous absorption and metabolism of amino acid and glucose are effectively promoted, the gas production rate, the short-chain fatty acid yield and the microbial protein concentration of fresh pig manure in-vitro fermentation can be increased, and the pH value is reduced.

Description

Technical Field

[0001] The invention belongs to the field of animal nutrition and feed, and more specifically, relates to a low-protein diet for pigs with optimized starch composition to balance energy and nitrogen. Background Art

[0002] For pig production, protein resource shortage and environmental pollution are the two major bottlenecks restricting the development of the pig industry. Soybean meal is the main protein raw material in animal feed. In recent years, the price of soybean meal has continued to rise, causing huge economic pressure on the breeding industry. In addition, traditional corn-soybean meal-based diets contain more soybean meal to meet the pig's demand for lysine, but cause excessive amounts of other essential amino acids, leading to excessive nitrogen excretion in feces and urine. The current problems facing pig feed can be solved by reducing the crude protein content of the diet. Promoting low-protein diets can save feed resources and costs, reduce nitrogen emissions, and protect the environment. At the same time, it can also reduce the metabolic burden of animals, promote intestinal health, and improve the utilization of nutrients. Low-protein diets refer to diets in which the crude protein level of the diet is reduced by 2 to 4 percentage points according to the existing nutritional requirements standards, and synthetic amino acids of appropriate types and quantities are added to meet the growth and production of livestock and poultry.

[0003] In addition, in low-protein diets, the amino acid nutritional needs of pigs are met by supplementing industrial crystalline amino acids (lysine, methionine, threonine, tryptophan). However, compared with amino acids, the digestion and absorption of energy feeds (corn, etc.) are relatively slow. This asynchrony will result in the inability to fully exert the protein synthesis-promoting effect of glucose and increase intestinal oxidative losses. Common energy feed corn has a high content of amylose. Compared with amylose, amylopectin has a reticular structure, which will induce greater gelatinization in the gastrointestinal tract of animals and has a larger contact area with digestive enzymes. It can be quickly digested by livestock and poultry and absorbed in the form of glucose.

[0004] The invention of CN103478494B, "A low-protein diet premix and feed for growing pigs", states that the low-protein diet premix for growing pigs, by weight percentage, mainly includes: stone powder 29.14-32.58%, calcium hydrogen phosphate 10.06-11.39%, salt 9.06-9.95%, L-lysine hydrochloride 10.68-12.33%, DL-methionine 2.66-3.11%, L-tryptophan hydrochloride 1.01- 1.36%, L-threonine hydrochloride 3.25-4.27%, L-valine 1.99-2.83%, vitamin additives 1.00-1.35%, trace element additives 1.28-1.85%, growth promoter 0.27-0.30%, choline chloride 2.37-2.70%, complex enzyme preparation 0.94-1.23%, high temperature resistant phytase 0.29-0.35%, antioxidant 0.36-0.46%, and the remaining ingredients are carriers. The growing pig feed is composed of the low-protein diet premix for growing pigs and the low-protein diet. The low-protein diet premix for growing pigs accounts for 4% of the total weight of the feed. The low-protein diet is composed of granular or powdered corn, soybean meal, wheat bran and one or more of inferior flour, rice bran, cottonseed meal, and rapeseed meal. The crude protein content of the feed is 14.0-15.0%. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an optimized low-protein diet for pigs with nitrogen balance.

[0006] In order to solve the above technical problems, the present invention provides a low-protein diet for pigs with optimized starch composition to balance energy and nitrogen, which is composed of the following ingredients by weight: 45-47% corn, 16-18% (preferably 17%) corn substitute, 17-21% barley, 7.7-12.1% soybean meal, 1.7-2.3% soybean oil, 1.6-2% bran, 0.60-0.75% calcium hydrogen phosphate, 0.61-0.82% stone powder, 0.41-0.43% lysine hydrochloride, 0.18-0.2% methionine (DL-methionine), 0.23-0.25% threonine (L-threonine), 0.09-0.11% tryptophan (L-tryptophan), and 1.9-2.1% premix; the above components are calculated on a dry matter basis;

[0007] The corn substitute is any one of the following: dry fried corn, cassava chunks, and cassava starch.

[0008] Note: Corn substitutes have a high content of amylopectin and are easier to digest and absorb, making the energy better match the digestion and absorption rate of amino acids in low protein, so they are called "balanced energy nitrogen."

[0009] Soybean meal is a protein feed, while corn, corn substitutes (dried corn, cassava chunks, cassava starch), barley, soybean oil, and bran are energy feeds.

[0010] As an improvement of the low-protein diet for pigs of the present invention:

[0011] Each 20g premix is ​​composed of the following ingredients: lysine 4.5g, methionine 1.2g, threonine 1.8g, calcium hydrogen phosphate 4g, sodium chloride 3.5g, iron 130mg, copper 25mg, manganese 41.9mg, zinc 100mg, iodine 0.4mg, selenium 0.3mg, VA 7000IU, VD 3 500IU, VE 55IU, VK 3.25mg, VB 1 1.3mg, VB 2 4.5mg, VB 6 3mg, VB 12 20μg, niacin 15mg, pantothenic acid 15mg, folic acid 0.85mg; the remainder is a carrier (for example, zeolite powder).

[0012] As a further improvement of the low-protein diet for pigs of the present invention, the formula is composed of the following ingredients by weight: 46.38% corn, 17% dry fried corn, 20.52% barley, 7.7% soybean meal, 2% soybean oil, 2% bran, 0.63% calcium hydrogen phosphate, 0.82% stone powder, 0.42% lysine hydrochloride, 0.19% methionine (DL-methionine), 0.24% threonine (L-threonine), 0.1% tryptophan (L-tryptophan), and 2% premix; the above components are calculated on a dry matter basis.

[0013] In the present invention:

[0014] The crude protein content of the diet is about 12.32%, and the amino acid nutritional needs of pigs are met by supplementing industrial crystalline amino acids (lysine, methionine, threonine, and tryptophan);

[0015] The crude protein content of the diet can be obtained by multiplying the amount of corn, corn substitutes, barley, soybean meal, bran, lysine, and methionine by their respective crude protein content.

[0016] Use corn substitutes (dried corn, cassava chunks, or cassava starch) to replace about 27% of the corn (i.e., the replacement amount is about 27%) to optimize the starch composition of the feed so that the digestion and absorption rate of the energy feed can match that of the amino acids;

[0017] Substitution amount = corn substitute amount ÷ (corn amount + corn substitute amount);

[0018] Both corn and corn substitutes contain amylose and amylopectin, but the amylopectin content of corn substitutes is higher than that of corn, so the composition of starch can be optimized.

[0019] The present invention also provides a method for preparing the above-mentioned diet, comprising the following steps:

[0020] The ingredients are weighed according to the above formula, and the solid ingredients are crushed to pass through a 1 mm sieve; calcium hydrogen phosphate, stone powder, lysine hydrochloride, methionine (DL-methionine), threonine (L-threonine), tryptophan (L-tryptophan), premix and soybean oil are premixed, and then corn, corn substitutes, barley, soybean meal, and bran are added and mixed evenly.

[0021] The low-protein diet for pigs can effectively reduce the crude protein content in the diet for pigs on the basis of meeting the nutritional needs of pigs, and at the same time, dry-fried corn, cassava pieces, or cassava starch is used to replace about 27% of corn to optimize the starch composition of the feed. Adding dry-fried corn to the feed can effectively increase the gas production, short-chain fatty acid production and microbial protein concentration of fresh pig manure in vitro fermentation, and reduce the pH value.

[0022] The present invention also provides the use of feed (dairy diet) in in vitro fermentation of fresh pig manure. The use of the low-protein pig diet of the present invention can significantly increase the gas production, short-chain fatty acid yield and microbial protein concentration of in vitro fermentation of fresh pig manure, and significantly reduce the pH value.

[0023] The beneficial effects of the present invention are mainly reflected in:

[0024] The feed provided by the present invention is an optimized low-protein diet for pigs with energy and nitrogen balance. The feed (low-protein diet for pigs) effectively reduces the crude protein content in the diet for pigs by supplementing crystalline amino acids on the basis of meeting the nutritional needs of pigs, and simultaneously uses dry fried corn and the like to replace about 27% of corn, optimizes the starch composition of the feed, effectively promotes the synchronous absorption and metabolism of amino acids and glucose, can increase the gas production, short-chain fatty acid yield and microbial protein concentration of fresh pig manure fermentation in vitro, and reduces the pH value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0026] Figure 1 The effects of four different feeds on the cumulative gas production at each time point of in vitro fermentation;

[0027] Figure 2 The effects of four different feeds on pH value at different time points of in vitro fermentation;

[0028] Figure 3 The effects of four different feeds on the acetic acid concentration at different time points of in vitro fermentation;

[0029] Figure 4 The effects of four different feeds on the propionic acid concentration at different time points of in vitro fermentation;

[0030] Figure 5 The effects of four different feeds on butyrate concentration at different time points of in vitro fermentation;

[0031] Figure 6 The effects of four different feeds on the concentration of valeric acid at different time points in vitro fermentation;

[0032] Figure 7 The effects of four different feeds on the isobutyric acid concentration at different time points of in vitro fermentation;

[0033] Figure 8 The effects of four different feeds on the concentration of isovaleric acid at different time points in in vitro fermentation;

[0034] Fig. 9 The effects of four different feeds on the total acid concentration at different time points of in vitro fermentation;

[0035] Fig.10 The effects of four different feeds on the ammonia nitrogen concentration at different time points of in vitro fermentation;

[0036] Fig.11 The effects of four different feeds on the concentration of microbial protein at different time points in in vitro fermentation;

[0037] In the figure: 100% corn represents comparative example 1, 27% puffed corn represents example 1; 27% cassava represents example 2, and 27% tapioca represents example 3. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0039] In the present invention:

[0040] The preparation method of the dry-fried corn is as follows: the corn is placed in a heating chamber and baked at a temperature of 185-195° C. for 150-180 seconds, the corn is immediately crushed to pass through a 2 mm sieve after baking, and then naturally cooled to room temperature after crushing.

[0041] As a conventional feed raw material, stone powder can be obtained through conventional commercial methods.

[0042] Example 1: An optimized nitrogen-balanced low-protein diet for pigs, the formula of which is (i.e., composed of the following ingredients by weight):

[0043] Corn 46.38%, dry fried corn 17%, barley 20.52%, soybean meal 7.7%, soybean oil 2%, bran 2%, calcium hydrogen phosphate 0.63%, stone powder 0.82%, lysine hydrochloride 0.42%, DL-methionine 0.19%, L-threonine 0.24%, L-tryptophan 0.1%, premix 2%. The above components are calculated on a dry matter basis.

[0044] Each 20g premix is ​​composed of the following ingredients: lysine 4.5g, methionine 1.2g, threonine 1.8g, calcium hydrogen phosphate 4g, sodium chloride 3.5g, iron 130mg, copper 25mg, manganese 41.9mg, zinc 100mg, iodine 0.4mg, selenium 0.3mg, VA 7000IU, VD 3 500IU, VE 55IU, VK 3.25mg, VB 1 1.3mg, VB 2 4.5mg, VB 6 3mg, VB 12 20μg, niacin 15mg, pantothenic acid 15mg, folic acid 0.85mg, and the balance is zeolite powder as a carrier.

[0045] The preparation method is:

[0046] According to the above formula, the solid components are weighed and crushed to pass through a 1 mm sieve. Calcium hydrogen phosphate, stone powder, lysine hydrochloride, methionine (DL-methionine), threonine (L-threonine), tryptophan (L-tryptophan), premix and soybean oil are premixed, and then corn, corn substitute (dry fried corn), barley, soybean meal and bran are added and mixed evenly to obtain a low-protein diet for pigs.

[0047] The nutritional level of the low-protein diet for pigs obtained in Example 1 is shown in Table 1.

[0048] Example 2, Example 3, Comparative Example 1:

[0049] The formula in Example 1 was changed (as shown in Table 1 below), the premix remained unchanged, and the preparation method was the same as that of Example 1, to obtain corresponding Example 2, Example 3, and Comparative Example 1; their nutritional levels are shown in Table 1.

[0050] Note: When the corn substitute is cassava chunks or cassava starch, it needs to be ground first, just like dry-fried corn.

[0051] Table 1 Feed composition and nutritional level of the embodiments and comparative examples (air-dried basis, mass percentage)

[0052]

[0053]

[0054] Note: Nutritional levels are calculated values ​​based on the "China Feed Composition and Nutritional Value Table (2022 33rd Edition)". Crude protein (%) refers to the total crude protein content of the diet.

[0055] Experiment 1: In vitro fermentation test of feeds of Examples 1-3 and Comparative Example 1

[0056] The in vitro fermentation system consists of 0.5 g of diet (i.e., the diet of Examples 1-3 and Comparative Example 1, see Table 1), 45 ml of culture medium (formula see Table 2) and 5 ml of fresh feces dilution of growing and finishing pigs, which simulates the digestive environment of the posterior end of the colon. The in vitro fermentation system is placed in a gas-generating bottle for fermentation test.

[0057] Table 2 In vitro fermentation medium formula

[0058]

[0059] The preparation method of the fresh feces dilution is as follows: the fresh pig feces are collected from 5 fresh feces samples of growing and finishing pigs with similar age and weight and an average weight of (55.0±5.0) kg by rectal stimulation method. Equal weights of feces are weighed from the 5 fresh feces samples, and the mixed feces samples are mixed with 37°C sterile physiological saline at a ratio of 1g / 5ml (W / V), and then filtered with 4 layers of sterile gauze to remove impurities to obtain the fresh feces dilution.

[0060] All gas-producing bottles were cultured at a constant temperature of 37°C for 48 h. The pressure values ​​in the gas-producing bottles at 0, 4, 10, 18, 24, and 48 h of fermentation were recorded using a pressure sensor, and fermentation samples were collected at 0, 4, 10, 18, 24, and 48 h of fermentation. At the end of the culture, the gas-producing bottles were taken out of the incubator and placed in ice water to stop the fermentation. The pH value was measured using a pH meter (Shanghai Yidian Scientific Instrument Co., Ltd.; Shanghai; China) and calibrated with a standard solution before use. The SCFA concentration was measured using a gas chromatograph (GC-2010; Shimadzu Corporation; Kyoto; Japan). The fermentation broth was stored in a refrigerator at -20°C to analyze ammonia nitrogen (NH 3 -N), microbial protein (MCP) and volatile fatty acids (VFA) content. t ) is calculated by the following formula: t =P t ×(V 0 -50) / (101.3×W)

[0061] Where: GP t is the gas production of the sample in time period t (ml / g DM); P t is the pressure (mPa) read during time period t; V 0is the volume of the bottle (mL); 101.3 is the standard atmospheric pressure (mPa); W is the dry matter weight of the feed substrate (daily diet) (g). The total accumulated gas production during the gas production process is the sum of the gas production in each time period.

[0062] Ammonia nitrogen concentration was determined by salicylic acid-hypochlorite colorimetric method.

[0063] Microbial protein concentration was determined using Coomassie Brilliant Blue staining.

[0064] The results are as follows Figure 1-11 shown.

[0065] Figure 1 The results of cumulative gas production at different time points are given in the figure. The cumulative gas production of 27% puffed corn level (Example 1) at 4h and 10h of fermentation was significantly higher than that of 27% cassava level (Example 2), 27% tapioca level (Example 3) and 100% corn level (Comparative Example 1) (P<0.05), and was significantly higher than that of 27% tapioca level (Example 3) at 18h (P<0.05). Figure 2 The changes in pH at different time points are shown. At 4h and 10h of fermentation, the pH of 27% puffed corn was significantly lower than that of 27% cassava, 27% tapioca and 100% corn (P<0.05). At 48h of fermentation, the pH of 27% tapioca was significantly higher than that of 27% cassava, 27% puffed corn and 100% corn (P<0.05).

[0066] Further testing of the SCFA concentration of the fermentation broth at each time period revealed the following results: Figure 3-9 As shown. The concentrations of acetic acid, propionic acid, valeric acid and total acid at 27% puffed corn level for 18h, 24h and 48h were significantly higher than those at 100% corn level (P<0.05). The concentrations of acetic acid, propionic acid, valeric acid and total acid at 27% cassava and 27% tapioca level for 48h were significantly higher than those at 100% corn level (P<0.05).

[0067] The results of ammonia nitrogen concentration are as follows Fig.10 As shown, the overall trend was to increase first and then decrease. In the early stage of fermentation (4h, 10h), the increase in ammonia nitrogen concentration at the 27% puffed corn level was the smallest.

[0068] Microbial protein concentration results are as follows Fig.11As shown. At 10h of fermentation, the microbial protein concentration of 27% puffed corn was significantly higher than that of 27% cassava, 27% tapioca and 100% corn (P<0.05). At 24h and 48h of fermentation, there was no significant difference among 27% puffed corn, 27% tapioca and 100% corn (P>0.05), but 27% cassava was significantly lower than 100% corn (P<0.05).

[0069] In summary, it can be seen that among the three cases of Examples 1 to 3, Example 1 is the preferred case.

[0070] Comparative Example 2: With respect to Example 1, "corn 46.38%, dry-fried corn 17%" is changed to "corn 0%, dry-fried corn 63.38%", that is, dry-fried corn is used to replace 100% of the corn. At this time, the crude protein content of the diet is 12.6%; the rest is the same as Example 1.

[0071] The experimental data of Comparative Example 2 and Example 1 are compared as follows:

[0072] In terms of cumulative gas production, the comparative example 2 (using dry fried corn to replace 100% of the corn group) was lower than that of the example 1 (using dry fried corn to replace about 27% of the corn group) at 0h, 4h, 10h, 18h, and 48h.

[0073] In terms of pH value, Comparative Example 2 was higher than Example 1 at 0h, 4h, 10h, 18h, 24h and 48h.

[0074] In terms of microbial protein content, Comparative Example 2 was lower than Example 1 at 0h, 10h, and 18h.

[0075] The acetic acid and propionic acid contents of Comparative Example 2 are lower than those of Example 1.

[0076] Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A low-protein diet for pigs with optimized starch composition to balance energy and nitrogen, characterized in that The formula is composed of the following ingredients by weight: 45-47% corn, 16-18% corn substitute, 17-21% barley, 7.7-12.1% soybean meal, 1.7-2.3% soybean oil, 1.6-2% bran, 0.60-0.75% calcium hydrogen phosphate, 0.61-0.82% stone powder, 0.41-0.43% lysine hydrochloride, 0.18-0.2% methionine, 0.23-0.25% threonine, 0.09-0.11% tryptophan, 1.9-2.1% premix; the above ingredients are calculated on a dry matter basis; The corn substitute is any one of the following: dry fried corn, cassava chunks, and cassava starch.

2. The low-protein diet for pigs according to claim 1, characterized in that: Each 20g premix is ​​composed of the following ingredients: lysine 4.5g, methionine 1.2g, threonine 1.8g, calcium hydrogen phosphate 4g, sodium chloride 3.5g, iron 130mg, copper 25mg, manganese 41.9mg, zinc 100mg, iodine 0.4mg, selenium 0.3mg, VA 7000IU, VD3500IU, VE 55IU, VK 3.25mg, VB1 1.3mg, VB2 4.5mg, VB6 3mg, VB 12 20μg, niacin 15mg, pantothenic acid 15mg, folic acid 0.85mg; the remainder is carrier.

3. The low-protein diet for pigs according to claim 1 or 2, characterized in that: The formula is composed of the following ingredients in weight content: 46.38% corn, 17% dry fried corn, 20.52% barley, 7.7% soybean meal, 2% soybean oil, 2% bran, 0.63% calcium hydrogen phosphate, 0.82% stone powder, 0.42% lysine hydrochloride, 0.19% methionine, 0.24% threonine, 0.1% tryptophan, and 2% premix; the above components are calculated on a dry matter basis.

4. The low-protein diet for pigs according to any one of claims 1 to 3, characterized in that: The crude protein content of the diet was 12.32%.

5. The method for preparing a diet according to any one of claims 1 to 4, characterized in that The following steps are involved: Weigh the ingredients according to the above formula, and crush the solid ingredients until they pass through a 1 mm sieve; Calcium hydrogen phosphate, stone powder, lysine hydrochloride, methionine, threonine, tryptophan, premix and soybean oil are premixed, and then corn, corn substitute, barley, soybean meal and bran are added and mixed evenly.

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