Feed for reducing activity of urease in pig manure and preparation method thereof

Abstract

The invention discloses a feed for reducing urease activity of pig manure and a preparation method, the feed is prepared by fermenting the following components by weight percent through yeast: 80%-90% of grape branch and leaf powder, 3%-12% of glucose and 5%-12% of sodium acetate, the preparation method of the feed comprises the following steps: crushing fresh grape branches and leaves into granules, drying the granules, crushing and sieving, and drying the granules to obtain the feed for reducing urease activity of pig manure. Obtaining grape branch and leaf powder; mixing grape branch and leaf powder, glucose and sodium acetate, uniformly stirring, adding purified water to adjust moisture, mixing, pretreating, and sterilizing to obtain a grape branch and leaf powder mixed raw material; performing static culture on saccharomycetes by using a wort liquid culture medium to obtain a fermentation bacteria solution; the fermented bacterial liquid is inoculated to the grape branch and leaf powder mixed raw material according to the mass proportion of 4%-8%, the feed is obtained through fermentation, the feed can effectively reduce the ammonia content in the breeding environment and the activity of pig manure urease, and the preparation method is simple, safe and environmentally friendly.

Description

Technical Field

[0001] The present invention belongs to the technical field of feeds, and particularly relates to a feed for reducing the urease activity of pig feces and a preparation method thereof. Background Art

[0002] During the process of grape planting and management, there are many discarded grape branches trimmed. Most of this resource is randomly stacked or burned, without being effectively developed and utilized, resulting in serious waste of resources and environmental pollution. When grape branches are directly fed to pigs, due to anti-nutritional factors and the characteristics of being difficult to digest, the utilization rate is relatively low.

[0003] The pig farming industry in China has developed rapidly, but the accompanying increase in fecal and sewage has increased significantly, seriously polluting the ecological environment and endangering the health of humans and pigs. The odor gases generated by large-scale pig farms, among which ammonia, due to its large emissions and strong irritation, causes the most serious environmental problems. Ammonia can acidify the environment, enrich nitrogen in the soil and cause soil compaction, and pollute surface water and groundwater. If the amount of ammonia is large and exists for a long time, it will also endanger the health of humans and pigs. Urea produced by protein metabolism in pigs enters the digestive tract and is decomposed into ammonia under the action of intestinal microbial urease; in addition, nitrogen-containing organic substances such as feces and urine accumulated in the pigsty are decomposed into ammonia under the action of microbial urease. Urease, a nickel-containing oligomeric enzyme, is an enzyme that specifically catalyzes the hydrolysis of urea into ammonia and carbon dioxide, with high specificity, widely present in microorganisms and animal and plant tissues, and the optimal pH value is 7.4. The supply of nickel element and the intestinal pH value have a great influence on its activity. Therefore, reducing the urease activity in the intestines and feces of pigs has become an important technical means for ammonia emission reduction in the current aquaculture industry. Summary of the Invention

[0004] The purpose of the present invention is to solve at least one problem in the prior art, and to propose a feed for reducing the urease activity of pig feces and a preparation method thereof.

[0005] To achieve the above purpose, the present invention provides a feed for reducing the urease activity of pig feces, which is prepared by fermenting the following components by mass percentage with yeast: 80%-90% grape branch and leaf powder, 3%-12% glucose, and 5%-12% sodium acetate.

[0006] As an optional implementation manner, the feed is prepared by fermenting the following components by mass percentage with yeast: 82% grape branch and leaf powder, 10% glucose, and 8% sodium acetate.

[0007] As an optional implementation manner, the feed is prepared by fermenting the following components by mass percentage with yeast: 85% grape branch and leaf powder, 5% glucose, and 10% sodium acetate.

[0008] As an alternative embodiment, the feed is made from the following components by mass percentage after fermentation with yeast: 80% grapevine leaf powder, 8% glucose, and 12% sodium acetate.

[0009] As an alternative embodiment, when the feed is used for feeding live pigs, the addition amount in each ton of live pig diet is 2% - 5%.

[0010] The present invention also provides a method for preparing a feed for reducing the urease activity in pig manure, which includes the following steps: Crush fresh grapevine leaves into pellet feed, dry the pellet feed until the moisture content is 13% - 15%, continue to crush, and sieve to obtain grapevine leaf powder; Mix the grapevine leaf powder, glucose, and sodium acetate, stir evenly, then add purified water to adjust the moisture to 25% - 35%, perform mixed pretreatment, and sterilize to obtain a mixed raw material of grapevine leaf powder; Static - culture yeast with wort liquid medium to obtain a fermentation broth; Inoculate the fermentation broth onto the mixed raw material of grapevine leaf powder at a mass ratio of 4% - 8%, and ferment at a temperature of 20°C - 30°C for 120h - 200h to obtain the feed.

[0011] As an alternative embodiment, the size of the pellet feed is 2cm - 3cm, and the sieving is carried out using a 20 - mesh to 30 - mesh sieve.

[0012] As an alternative embodiment, the sterilization is carried out by the 115°C sterilization method, and the sterilization time is 10min - 30min.

[0013] As an alternative embodiment, the time for the mixed pretreatment is controlled within 1h - 2h.

[0014] As an alternative embodiment, when static - culturing yeast with wort liquid medium, the temperature is controlled at 25°C - 35°C, and the culturing time is controlled within 18h - 36h.

[0015] Introduction to the efficacy of the feed components and preparation method: The rich organic matter and nutrient elements in grapevine leaves, especially the rich antioxidant factors. Adding fermented grapevine leaves to the pig diet, the organic acids, digestive enzymes, and probiotics produced after fermentation of grapevine leaves have a certain promoting effect on the intestinal health of pigs, can regulate the intestinal structure and function, microbial flora, and pH value of live pigs, and reduce the emission of breeding odors.

[0016] Specifically, by fermenting grapevine leaves and twigs with yeast, macromolecular substances such as cellulose, hemicellulose, and lignin in grapevine leaves and twigs can be enzymatically hydrolyzed into easily absorbable small-molecule sugars (such as glucose and xylose) and organic acids (such as lactic acid and acetic acid), and small peptides and free amino acids are generated, significantly improving the nutritional value. Yeast secretes cellulase, amylase, etc., decomposes cellulose into soluble sugars, and synthesizes microbial protein, increasing the crude protein content of the feed; yeast fermentation can degrade potential toxins in grapevine leaves and twigs (such as tannic acid) and mycotoxins in the feed, reducing the risk of poisoning; the organic acids produced by fermentation can lower the pH value of the feed, inhibit the growth of molds, and extend the shelf life; yeast colonizes in the pig intestine, inhibits the proliferation of pathogenic bacteria (such as Escherichia coli), and reduces the diarrhea rate; the fermented feed improves the utilization rate of phosphorus and nitrogen, reduces the emission of harmful gases such as ammonia and hydrogen sulfide in the feces, and reduces the odor in the pigsty; on the one hand, glucose serves as a carbon source for yeast, which can accelerate the fermentation process and promote the generation of metabolites such as B vitamins and volatile fatty acids, and on the other hand, it can directly supplement the energy requirements of live pigs. After fermentation, glucose combines with the decomposition products of grapevine leaves and twigs to form a composite nutrient matrix, enhancing palatability and masking the feed odor.

[0017] Sodium acetate can activate digestive enzymes, improve the digestion and absorption of feed by live pigs; effectively inhibit the reproduction of harmful microorganisms in the intestine; regulate the pH value of the gastrointestinal tract. In addition, the acetate ion in sodium acetate can reduce the toxicity of heavy metals; convert molecular ammonia in the body into a more stable ammonium salt, reducing the toxicity of ammonia nitrogen. The acetate ion has complexing properties and can provide coordination bonds to form complexes with nickel ions. The complexation reaction is due to the lone pair of electrons on the oxygen atom in the acetate ion, which can form coordination bonds with nickel ions, thus forming a stable complex, making the nickel element in the live pig body lose the opportunity to form a urease-active compound. On the one hand, sodium acetate can compete with urea for the urease binding site, reducing the urea decomposition rate, and can also bind to the urease catalytic group (such as sulfhydryl group), thereby reducing the urease activity in the feces; on the other hand, sodium acetate can lower the pH value of the gastrointestinal tract, inhibit the reproduction of harmful bacteria (such as Escherichia coli and Salmonella), and promote the growth of beneficial bacteria such as lactic acid bacteria, thus optimizing the intestinal microbial balance and reducing the precursor substances of ammonia produced by protein spoilage.

[0018] Advantages of the present invention: The present invention makes feed by fermenting glucose leaf and twig powder, glucose, and sodium acetate with yeast. Through the combined action of the fermentation process and components, it improves the palatability of the feed, increases the nutritional components, effectively reduces the ammonia content in the breeding environment and the urease activity of pig feces; when feeding live pigs, adding 2%-5% of the feed of the present invention to each ton of live pig diet reduces the feed cost; the whole preparation method is simple, safe and environmentally friendly, and improves the resource utilization rate of glucose leaves and twigs.

[0019] The features and advantages of the present invention will be described in detail through examples. Detailed implementation manners

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following will clearly and completely describe the technical solutions of this application in combination with the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of the embodiments.

[0021] Example 1 This example presents a feed for reducing the urease activity of pig manure. This feed is made from the following components by mass percentage after fermentation with yeast: 82% grape leaf and twig powder, 10% glucose, and 8% sodium acetate.

[0022] The preparation method of this feed is as follows: Crush fresh grape leaves and twigs into 2-cm granular materials, dry the granular materials until the moisture content is 15%, continue to crush, and pass through a 30-mesh sieve to obtain grape leaf and twig powder; Mix grape leaf and twig powder, glucose, and sodium acetate in proportion, stir evenly, add pure water to adjust the moisture to 30%, perform a mixed pretreatment for 1 h, sterilize at 115°C for 15 min, and cool to room temperature to obtain a mixed raw material of grape leaf and twig powder; Use a wort liquid medium to statically culture yeast at 25°C for 24 h to obtain a fermented bacterial liquid; Inoculate the fermented bacterial liquid onto the mixed raw material of grape leaf and twig powder at a mass ratio of 6%, and ferment at 25°C for 144 h to obtain the feed.

[0023] After measurement, the crude fiber content of the prepared feed is 64.0%.

[0024] Example 2 This example provides a feed for reducing the urease activity of pig manure. This feed is made from the following components by mass percentage after fermentation with yeast: 85% grape leaf and twig powder, 5% glucose, and 10% sodium acetate.

[0025] The preparation method of this feed is as follows: Crush fresh grape leaves and twigs into 3-cm granular materials, dry the granular materials until the moisture content is 14%, continue to crush, and pass through a 25-mesh sieve to obtain grape leaf and twig powder; Mix grape leaf and twig powder, glucose, and sodium acetate in proportion, stir evenly, add pure water to adjust the moisture to 25%, perform a mixed pretreatment for 1.5 h, sterilize at 115°C for 20 min, and cool to room temperature to obtain a mixed raw material of grape leaf and twig powder; Use a wort liquid medium to statically culture yeast at 30°C for 18 h to obtain a fermented bacterial liquid; The fermented bacterial liquid was inoculated onto the mixed raw material of grapevine leaf powder at a mass ratio of 8%, and fermented at 28 °C for 120 h to obtain the feed.

[0026] After determination, the crude fiber content of the prepared feed was 62.0%.

[0027] Example 3 This example provides a feed for reducing the urease activity of pig manure, which is prepared by fermenting the following components by mass percentage: 80% grapevine leaf powder, 8% glucose, and 12% sodium acetate.

[0028] The preparation method of this feed is as follows: The fresh grapevine leaves were crushed into pellets with a size of 2.5 cm, and the pellets were dried to a moisture content of 13%, then further crushed and passed through a 20-mesh sieve to obtain grapevine leaf powder; The grapevine leaf powder, glucose, and sodium acetate were mixed in proportion, stirred evenly, then pure water was added to adjust the moisture to 35%, and the mixture was pretreated for 2 h and sterilized at 115 °C for 30 min, and then cooled to room temperature to obtain the mixed raw material of grapevine leaf powder; The yeast was statically cultured in a malt extract liquid medium at 32 °C for 36 h to obtain the fermented bacterial liquid; The fermented bacterial liquid was inoculated onto the mixed raw material of grapevine leaf powder at a mass ratio of 4%, and fermented at 30 °C for 200 h to obtain the feed.

[0029] After determination, the crude fiber content of the prepared feed was 63.0%.

[0030] Control Example 1 This control example provides a feed, which has the same components and preparation method as Example 1 except that it does not contain sodium acetate.

[0031] Control Example 2 This control example provides a feed, which consists of the following components by mass percentage: 82% grapevine leaf powder, 10% glucose, and 8% sodium acetate. The preparation method of this feed is the same as that of Example 1 except that it does not contain the steps of yeast culture and fermentation.

[0032] Control Example 3 This control example provides a feed, which is prepared by fermenting the following components by mass percentage: 80% grapevine leaf powder, 5% glucose, and 15% sodium acetate. The preparation method is the same as that of Example 1.

[0033] Control Example 4 This comparative example provides a feed, which is made from the following components by mass percentage after fermentation with yeast: 88% grapevine leaf powder, 10% glucose, and 2% sodium acetate. The preparation method is the same as that of Example 1.

[0034] Comparative Example 5 This comparative example provides a feed. Except that acetohydroxamic acid is used instead of sodium acetate, the other components, their ratios, and the preparation method of the feed are the same as those of Example 1.

[0035] Regarding the effects of different feeds on the urease activity of piglet feces and the ammonia content in the environment when feeding piglets Select 350 piglets of the same breed and weight, divide them into 7 groups on average, and raise them in the same environment. The 7 groups of piglets are fed with standard diet + 3% of the feed of Example 1 (denoted as the experimental group), standard diet (denoted as control group 1), standard diet + 3% of the feed of Comparative Example 1 (denoted as control group 2), standard diet + 3% of the feed of Comparative Example 2 (denoted as control group 3), standard diet + 3% of the feed of Comparative Example 3 (denoted as control group 4), standard diet + 3% of the feed of Comparative Example 4 (denoted as control group 5), and standard diet + 3% of the feed of Comparative Example 5 (denoted as control group 6). Feed for 30 days, and measure the urease activity of piglet feces and the ammonia concentration in the environment every day. When measuring, repeat the measurement 3 times and take the average value. The urease activity of piglet feces is the value obtained by statistically counting the milligrams of ammonia nitrogen produced by the fecal samples. The specific test results are shown in Table 2 below. Among them, the formula of the standard diet is shown in Table 1.

[0036] Table 1 Composition and nutritional indexes of the standard diet

[0037] Table 2 Comparison table of urease activity of piglet feces and ammonia concentration in the environment under different feeds

[0038] As can be seen from Table 2, the urease activity of piglet feces and the ammonia concentration in the environment of the experimental group are lower than those of each control group. Compared with control group 1, the urease activity of pig feces in the experimental group decreased by 75.8% (P < 0.01), and the ammonia concentration in the pigsty environment of the experimental group decreased by 73.4% (P < 0.01). It shows that the combined action of the fermentation process and sodium acetate can effectively reduce the ammonia concentration in the environment. Adding sodium acetate has a better inhibitory effect on the urease activity of piglet feces than the conventional urease inhibitor acetohydroxamic acid. Too high or too low addition ratio of sodium acetate will also affect the inhibitory effect on the urease activity of piglet feces.

[0039] The above embodiments are illustrative of the present invention, not limiting the present invention. Any simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. A feed for reducing the urease activity of pig manure, characterized in that, The feed is prepared by fermenting the following components by mass percentage: 80%-90% grapevine leaf powder, 3%-12% glucose, and 5%-12% sodium acetate.

2. The feed for reducing the urease activity of pig manure according to claim 1, characterized in that: The feed is prepared by fermenting the following components by mass percentage: 82% grapevine leaf powder, 10% glucose, and 8% sodium acetate.

3. The feed for reducing the urease activity of pig manure according to claim 1, characterized in that: The feed is prepared by fermenting the following components by mass percentage: 85% grapevine leaf powder, 5% glucose, and 10% sodium acetate.

4. The feed for reducing the urease activity of pig manure as described in claim 1, characterized in that: The feed is prepared by fermenting the following components by mass percentage: 80% grapevine leaf powder, 8% glucose, and 12% sodium acetate.

5. The feed for reducing the urease activity of pig manure according to claim 1, characterized in that: When the feed is used for feeding live pigs, the addition amount in each ton of live pig diet is 2%-5%.

6. A preparation method of a feed for reducing the urease activity of pig manure, characterized in that, It includes the following steps: Crush fresh grapevine leaves into granular feed, dry the granular feed until the moisture content is 13%-15%, continue to crush and screen to obtain grapevine leaf powder; Mix grapevine leaf powder, glucose, and sodium acetate, stir evenly, add pure water to adjust the moisture to 25%-35%, perform mixed pretreatment, and sterilize to obtain a mixed raw material of grapevine leaf powder; Static culture the yeast using a wort liquid medium to obtain a fermented bacterial liquid; Inoculate the fermented bacterial liquid onto the mixed raw material of grapevine leaf powder at a mass ratio of 4%-8%, and ferment at a temperature of 20°C - 30°C for 120h - 200h to obtain the feed.

7. The preparation method of the feed for reducing the urease activity of pig manure as claimed in claim 6, wherein: The size of the granular feed is 2cm - 3cm, and screening is carried out using a 20-mesh - 30-mesh sieve.

8. The preparation method of the feed for reducing the urease activity of pig manure according to claim 6, characterized in that: The sterilization is carried out by a sterilization method at 115°C, and the sterilization time is 10min - 30min.

9. The preparation method of the feed for reducing the urease activity of pig manure according to claim 6, characterized in that: The time of the mixed pretreatment is controlled within 1h - 2h.

10. The preparation method of the feed for reducing the urease activity of pig manure according to claim 6, characterized in that: When the yeast is statically cultured using a wort liquid medium, the temperature is controlled at 25°C - 35°C, and the culture time is controlled at 18h - 36h.

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