CN115812858A

CN115812858A - Additive and application thereof in improving egg poultry production performance

Info

Publication number: CN115812858A
Application number: CN202210253769.9A
Authority: CN
Inventors: 王�忠; 王浦卉; 邵育静
Original assignee: China Agricultural University
Current assignee: China Agricultural University
Priority date: 2022-03-15
Filing date: 2022-03-15
Publication date: 2023-03-21

Abstract

The invention relates to the field of feed additives, in particular to an additive and application thereof in improving the production performance of laying poultry. The additive is copper laurate which is a complex of lauric acid and copper. When the additive is added into the feed for laying fowls, the egg quality and reproductive performance of healthy laying fowls can be improved; but also can improve the production performance of egg-laying poultry infected by escherichia coli, improve the intestinal health of the egg-laying poultry, increase beneficial bacteria and reduce harmful bacteria, thereby reducing the incidence rate of bacterial infection or performing adjuvant therapy when the infection occurs.

Description

Additive and application thereof in improving egg poultry production performance

Technical Field

The invention relates to the field of feed additives, in particular to an additive and application thereof in improving the production performance of laying poultry.

Background

Avian colibacillosis caused by avian pathogenic colibacillosis, such as O1, O2, O78, etc., is one of the major causes of losses in the poultry industry, and can affect poultry production at all ages and in all production types. Respiratory diseases such as infectious bronchitis, mycoplasma disease, newcastle disease, avian influenza, infectious rhinitis and the like infected by chickens, as well as immunosuppressive diseases such as avian leukemia, reticuloendotheliosis and the like are main reasons for inducing pathogenic colibacillosis of chickens. The breeding method has the advantages that the breeding of microorganisms such as escherichia coli in the environment can be caused, the disorder of intestinal flora of chickens can be caused, harmful bacteria or potential pathogenic bacteria such as escherichia coli can be greatly proliferated in intestinal tracts, the diarrhea and the morbidity of laying hens are caused, and the breeding method is a main cause for the occurrence of avian colibacillosis. Avian pathogenic escherichia coli in the environment can cause infection through respiratory tract and reproductive tract, wherein the infection of the pathogenic escherichia coli through the respiratory tract and the reproductive tract can cause the appearance of cellulose pericarditis, perihepatitis, ballooning disease, salpingitis, peritonitis, salpingitis syndrome, arthritis and even systemic bacteremia of laying hens. Coli infection is common in laying hens, can reduce the laying rate of laying hens, improve the egg fouling rate, the egg breakage rate, the light-color egg rate and the like, and seriously affects the laying hen production and the egg product quality. Coli infection also reduces hatching rates of hatching eggs and survival rates of chicks, particularly in egg breeder production.

The main measures currently used for preventing avian colibacillosis are: strengthen the biosafety control of the chicken coop, improve the feed and drinking water sanitation, improve the chicken feeding environment, regularly inoculate sensitive antibiotics and inoculate vaccines. But because the avian escherichia coli has a plurality of serotypes, and the cross protection of vaccines prepared by each serotype is not high; in addition, avian Escherichia coli is easy to generate multiple drug resistance to antibiotic treatment, so that the antibiotic treatment effect is not ideal and the antibiotic residues in the poultry products are caused. At present, more and more researches are focused on that substances such as Chinese herbal medicines, plant extracts, organic acids, probiotics, prebiotics and the like can improve the intestinal microflora of the laying hens and reduce the abundance of harmful bacteria such as escherichia coli and the like in the intestinal tract, so that the risk of escherichia coli infection is reduced, the healthy production of chicken flocks is realized, and the quality and the safety of egg products are improved.

According to the review, the research literature and patent reports on the application of antibiotic substitutes or clean egg production technology to prevent and control avian Escherichia coli infection are reported at present. Such as: 3238 Zxft 3238, etc., hanging an ozone generator in a chicken house, arranging ultraviolet lamps in a drinking water pipe, a feeding trough and an egg collecting trough, adding Chinese medicines into feed, and performing all-round sterilization treatment on space, drinking water, feed and eggs to ensure the production of clean eggs. Zhuang Xianglin, and the like, and the invention relates to a method for improving the microbial quantity of cecum of laying hens by using superfine ground tea powder (publication number: CN 107889789A), wherein the superfine ground tea powder is added into daily ration of the laying hens, so that the quantity of escherichia coli in the cecum of the laying hens is reduced, and the method is simple and convenient to use and strong in operability. However, the development of a safe and effective non-antibiotic substance for inhibiting enteric pathogens remains a technical problem for those skilled in the art.

Lauric acid is a saturated fatty acid containing 12 carbon atoms, and has white needle-like crystal at normal temperature and bay oil fragrance. Lauric acid is insoluble in water, soluble in organic solvents such as methanol, ether, chloroform and the like, has amphiphilicity and strong oxidation resistance, and can be stored for a long time. Lauric acid is contained in coconut oil in a large amount. Lauric acid and derivatives thereof can be rapidly metabolized and powered in animal bodies, regulate lipid metabolism and improve intestinal microorganisms of animals. Lauric acid and derivatives thereof have wide antibacterial, antiviral and antiparasitic effects and the like, and have good inhibition or killing effects on gram-positive bacteria such as clostridium perfringens, streptococcus, listeria and the like, certain gram-negative bacteria such as campylobacter, escherichia coli, salmonella and the like, enveloped viruses such as PEDV, PRRSV, african swine fever virus, avian influenza virus, vesicular stomatitis virus and the like, certain fungi, protozoa and the like. In addition, the lauric acid and the derivative thereof also have the immunoregulation effect. In the production of livestock and poultry, lauric acid and derivatives thereof are gradually used for promoting the growth of livestock and poultry, resisting infection, improving the intestinal health, improving the immune function and the like.

Copper is one of trace elements necessary for growth, development and production of animals, participates in biochemical processes such as oxidation-reduction reaction, electron transfer, collagen crosslinking and the like, and has the effects of inhibiting the generation of free radicals, influencing the absorption and utilization of trace elements such as iron, zinc, manganese and the like, regulating the function of immune cells and the expression of cytokines, maintaining the integrity of biological membranes and the like. Higher concentrations of copper have a strong inhibitory effect on microorganisms, especially gram-positive bacteria.

Disclosure of Invention

Firstly, the object of the present invention is to provide an additive which is copper laurate; the copper laurate is a complex of lauric acid and copper.

Preferably, the copper laurate contains copper in an amount of 11 to 15% by weight.

Preferably, the purity of the copper laurate is 95 to 99%.

When the additive copper laurate is applied to a microbial culture medium, the growth of escherichia coli and salmonella can be obviously inhibited. Wherein, the MIC range of the copper laurate to the escherichia coli is 8-16mg/mL, and the MIC range of the copper laurate to the salmonella is 16-32mg/mL.

Preferably, the copper laurate is a complex of lauric acid and copper chloride synthesized under alkaline conditions.

As a preferred embodiment, the copper laurate is prepared by the following method: mixing soluble copper salt and strong base solution to react to generate copper hydroxide precipitate, filtering to obtain precipitate, adding lauric acid to react, filtering again to obtain light blue crystal, drying and grinding the precipitate to obtain the copper laurate.

Further, the invention also provides a feed which contains the additive.

Preferably, the weight ratio of the additive in the feed is 0.01-0.06%.

When the additive with the proportion is added into the feed, the production performance of the laying poultry can be obviously improved, and particularly the egg quality and the reproductive performance of the laying poultry can be improved. And for egg-laying poultry, the addition amount of copper is in the safety range specified by the national standard.

Preferably, the weight ratio of the additive is 0.01 to 0.03%.

When 0.01 to 0.03 percent of additive by weight is added into the feed, the production performance of healthy laying poultry can be obviously improved, and particularly the egg quality and the reproductive performance of the healthy laying poultry can be improved; can also improve the production performance of the egg-laying poultry infected by the escherichia coli and improve the intestinal health of the egg-laying poultry infected by the escherichia coli.

Furthermore, the invention also provides the application of the additive and the feed in improving the quality of the eggshells of the laying birds; preferably, the laying poultry is laying hens or laying ducks; most preferably, the laying fowl is a laying hen.

When the additive with the weight ratio of 0.01-0.03% is added into the feed, the eggshell thickness and the eggshell strength of the eggs produced by the laying hens can be obviously improved.

Further, the present invention also provides the use of the above additive in the preparation of a feed or a medicament for the prevention or treatment of diseases caused by infection with Escherichia coli and/or Salmonella.

The better the inhibition of E.coli and/or Salmonella with increasing copper laurate concentration.

Preferably, the feed or medicament is used for the prevention or treatment of intestinal diseases caused by escherichia coli and/or salmonella infection. In particular avian colibacillosis.

Furthermore, the invention also provides a feeding method of laying hens, and the feed is adopted to feed breeding hens or commercial laying hens for 3-5 weeks in the later period of laying.

Under the feeding mode, the egg quality and reproductive performance of the laying poultry are further improved.

Those skilled in the art can further derive other preferred embodiments of the present invention by optimizing combinations of the above preferred embodiments.

Furthermore, the invention also provides a medicine which contains the additive and pharmaceutically acceptable auxiliary components.

The invention has the beneficial effects that: the egg quality and reproductive performance of healthy laying poultry are improved by adding copper laurate into the feed; but also can improve the production performance of egg-laying poultry infected by escherichia coli, improve the intestinal health of the egg-laying poultry, increase beneficial bacteria and reduce harmful bacteria, thereby reducing the incidence rate of bacterial infection or performing adjuvant therapy when the infection occurs.

Detailed Description

The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

The specific techniques or conditions not indicated in the examples are all conventional methods or techniques or conditions described in the literature of the field or according to the product specifications. The reagents and instruments used are conventional products which are available from normal commercial vendors, not indicated by manufacturers.

The copper laurate is prepared by the following method: mixing soluble copper salt and strong base solution to react to generate copper hydroxide precipitate, filtering to obtain precipitate, adding lauric acid to react, filtering again to obtain light blue crystal, drying and grinding the precipitate to obtain a copper laurate product. Wherein the purity of the copper laurate is 98 percent, which is equivalent to 84.4 percent of the lauric acid content and 13.6 percent of the copper content.

The copper laurate provided by the invention comprises the following specific preparation steps:

the first step is as follows: weighing 2-4 parts of sodium hydroxide, adding into a first reaction vessel, then adding 5-10 parts of water, and stirring while heating (the heating temperature is not more than 60 ℃) to dissolve; after the strong base is completely dissolved, weighing 1-2 parts of soluble copper salt (copper sulfate), adding into the prepared alkaline solution, and stirring for reaction for 2-4 hours to generate blue flocculent precipitate;

the second step is that: filtering the mixture of the blue flocculent precipitate and the solution by a filter system, and collecting the blue precipitate to obtain copper hydroxide precipitate;

the third step: adding water into a second reaction container, heating (about 60-70 ℃), then adding lauric acid while stirring, then adding sodium hydroxide, and continuously heating to completely dissolve the lauric acid to generate a sodium laurate solution;

the fourth step: mixing the prepared copper hydroxide with lauric acid according to the ratio of 1:2, adding the mixture into the sodium laurate solution, heating (controlling the temperature between 60 and 70 ℃) and stirring to fully mix and react for 2 to 4 hours to prepare a copper laurate solution, and cooling to the normal temperature;

the fifth step: filtering the copper laurate solution by a filter, and collecting the precipitate;

and a sixth step: drying the copper laurate precipitate mixture with hot air or naturally, grinding and sieving with a grinder, and drying to obtain light blue solid powder of copper laurate.

The basic daily ration adopted by the invention is corn-soybean meal type daily ration, is prepared according to NY/T-33-2004 feeding standard, is normally added with inorganic trace elements required by egg-laying hens, does not contain any antibiotics and antiparasitic drugs, and has the specific formula and the calculated nutritional level shown in Table 1.

Preparing daily ration for the laying hens according to the following steps:

the method comprises the following steps: calculating the stock preparation according to table 1;

step two: crushing corn and soybean meal according to parts by weight;

step three: uniformly mixing small materials (calcium hydrophosphate, salt, compound trace elements, 50% choline chloride, DL-methionine, compound vitamins and copper laurate according to the corresponding weight part of each group of feed) and the materials obtained in the second step according to the weight part;

step four: and (4) putting the materials obtained in the second step and the third step, stone powder and soybean oil into a mixer to be uniformly mixed, wherein the uniformity of the mixture is less than or equal to 5%, and obtaining various daily rations used in the test.

TABLE 1 basal diet formula and nutritional levels

Note: 1, the compound trace elements enable each kilogram of daily ration to contain: 80mg of iron, 10mg of copper, 60mg of manganese, 100mg of zinc, 0.3mg of selenium and 1.2mg of iodine.

2 the compound vitamin contains the following components in each kilogram of daily ration: VA12500IU, VD32500IU, VE18.75mg, VK32.65mg, VB12mg, VB26mg, VB120.025mg, pantothenic acid 12mg, nicotinic acid 50mg, folic acid 1.25mg and biotin 0.325mg.

Example 1

The embodiment provides a feed, and specifically copper laurate with the weight proportion of 0.02% is added into the basic ration.

Example 2

The embodiment provides a feed, and specifically, 0.04% by weight of copper laurate is added to the basic ration.

Example 3

The embodiment provides a feed, and specifically, 0.06% by weight of copper laurate is added to the basic ration.

Test example 1

The test example verifies the bacteriostatic effect of copper laurate on common gram-negative pathogenic bacteria of chicken infection, mainly escherichia coli and salmonella in vitro.

Experimental materials: escherichia coli O1 (strain preservation number: CVCC 1568), escherichia coli O2 (strain preservation number: CVCC 1565), escherichia coli O78 (strain preservation number: CVCC 1570), salmonella typhimurium ST, salmonella enteritidis SE and Salmonella pullorum SP all from the China veterinary culture collection center.

The method comprises the following specific steps: escherichia coli or salmonella bacteria and different doses of copper laurate are added into the nutrient broth, so that the concentrations of the copper laurate in the system are respectively 64mg/mL, 32mg/mL, 16mg/mL, 8mg/mL, 4mg/mL, 2mg/mL, 1mg/mL, 0.5mg/mL, 0.25mg/mL and 0.125mg/mL, and the final concentration of the bacteria is 10 Fahrenheit CFU/mL, and a negative control (no bacteria is added but copper laurate is added at each concentration) and a positive control (bacteria is added but no copper laurate is added) are arranged. After shaking culture at 37 ℃ for 24 hours, the OD at 600nm for each treatment was measured. The formula for calculating the bacteriostatic rate using Excel processed data is as follows: bacteriostatic rate (%) = (OD) _{To be measured} -OD _{Negative of} )/(OD _{Positive for} -OD _{Negative of} ) X 100%. It is generally accepted in the art that concentrations that achieve 95% inhibition and above are the Minimum Inhibitory Concentration (MIC) of copper laurate for that species of bacteria.

The test results are shown in table 2. As can be seen from Table 2, copper laurate reached more than 95% of inhibition rates to Escherichia coli O1, escherichia coli O2 and Escherichia coli O78 at concentrations of 8mg/mL, 8mg/mL and 16mg/mL, respectively, and copper laurate reached more than 95% of inhibition rates to Salmonella enteritidis, salmonella pullorum and Salmonella typhimurium at concentrations of 32mg/mL, 16mg/mL and 32mg/mL, respectively. The MIC of copper laurate for a certain bacterium is a range of values, since copper laurate, depending on the strain, has MIC values-that differ for different strains of the same species of bacterium. The MIC of copper laurate to E.coli ranges from 8 to 16mg/mL and the MIC to Salmonella ranges from 16 to 32mg/mL.

TABLE 2 bacteriostatic action of different doses of copper laurate on various coliforms and salmonella bacteria

Test example 2

The experimental example verifies the influence of the feed of the example on the quality and reproductive performance of eggs of the egg species. The method comprises the following specific steps:

144 helan brown egg breeders of 55 weeks old, near-weight, healthy and similar laying rate were selected and randomly divided into 4 treatment groups. The control group was fed basal diet, and the other 3 groups were fed with the feed of the examples at the same time in the later stage of egg laying.

Feeding 3 test chickens in a cage in a closed henhouse with environment control equipment such as a wet curtain and a fan, drinking water and feeding freely, and adopting an illumination program of 16h illumination and 8h darkness every day. Daily 8, 00, 14, 30 and 18. One week before formal test, the egg production number of each cage of chicken is recorded every day, and the chicken is divided into groups according to the egg production number regulation, so that the egg production number of each treatment group has no difference, and the alpha of the single-factor variance test is more than 0.95.

The official experiment lasted 8 weeks, and 30 eggs were randomly selected for egg quality determination for three consecutive days per treatment group per week. Egg shape index, egg shell strength, egg weight, yolk color, egg shell thickness were measured at room temperature using a DET6500 egg quality tester, an ESTG-01 model egg shell thickness meter and a vernier caliper, and the egg shell color was visually observed and scored. At the end of week 4 and 8, 100 hatching eggs were randomly selected for each treatment group for incubation test, and the number of dead embryos and the number of hatched embryos were counted.

The test results are shown in tables 3 and 4.

TABLE 3 Effect of different doses of copper laurate on the reproductive performance of Holland brown egg breeders

Compared with the control group, in the test of 4w, the dead embryo rate can be reduced and the hatching rate of the fertilized eggs can be improved by adopting the feeds of the examples 1 to 3. In the 8w test, the feed of the embodiment 3 can reduce the dead embryo rate and improve the hatching rate of the fertilized eggs.

TABLE 4 Effect of different doses of copper laurate on the quality of eggs of the Hailan brown egg species

Note: different letters in the same column indicate significant difference between two groups (P < 0.05), the same letters indicate insignificant difference between two groups (P > 0.05), and 0.50. Ltoreq. P < 0.10 indicates a trend. The following table is the same.

The thickness and strength of the eggshell are indexes for evaluating the quality of the eggshell. Compared with the control group, the eggshell thickness, the eggshell strength and the eggshell weight of the eggs produced by the laying hens fed with the feed of the examples for 4 weeks are obviously improved.

The darker the color of the eggshell of the brown-shell laying hen, the more favored the eggshell is by consumers. Compared with a control group, the color of the eggshell of the eggs produced by the laying hens fed with the feed of the examples is deepened to different degrees, which shows that the eggshell color can be deepened by supplementing the copper laurate.

Test example 3

The experimental example verifies the influence of the feed of the example on the production performance of escherichia coli infected laying hens and the influence of microorganisms in ileum chyme of the laying hens. The method comprises the following specific steps:

108 eggs infected by Escherichia coli of 55 weeks old are selected and randomly divided into three treatment groups. The control group was fed basal diet while being infected with E.coli, and the other 2 groups were fed with the feeds of examples 1 and 2, respectively, at the same time. The feeding environment and the feeding egg-picking procedure were the same as in test example 2. One week before the formal test, the egg laying number of each cage of chickens is recorded every day, and the chickens are divided into groups according to the egg laying number regulation, so that the egg laying number of each treatment group has no difference, and the alpha of the single-factor variance test is more than 0.95. The official trial lasted 1 week.

And (3) statistics of production performance: during the test period, the number of the chickens, the number of the eggs, the number of the dead chickens and the number of the unqualified eggs (broken eggs, soft eggs, dirty eggs, preserved eggs, deformed eggs, faded eggs and the like) are counted according to a repeated group, the weight of the eggs is weighed every day, and the rest materials are weighed at the end of the test. After feeding for one week, 6 laying hens are randomly selected from each treatment group to collect ileal chyme, and the number of lactic acid producing bacteria, escherichia coli, salmonella, clostridium perfringens and campylobacter is measured by a plate coating method after dilution in multiple proportion.

The test results are shown in tables 5 and 6.

TABLE 5 influence of different dosages of copper laurate on the productivity of E.coli infected layers

Compared with a control group, the feed of the embodiment 1 obviously improves the laying rate, the average daily feed intake and the average daily egg laying weight of the laying hens; the mortality rate and the rate of unqualified eggs are reduced.

TABLE 6 influence of different doses of copper laurate on the microorganisms in ileal chyme of layer chicken infected with E.coli

Compared with a control group, the feed in the example 1 can obviously reduce the abundance of harmful bacteria (escherichia coli, salmonella and campylobacter) in ileal chyme of the laying hens infected by escherichia coli, and can increase the abundance of beneficial bacteria lactic acid bacteria.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. An additive, wherein the additive is copper laurate; the copper laurate is a complex of lauric acid and copper.

2. The additive according to claim 1, wherein the copper content is 11 to 15% by weight.

3. A feed comprising the additive of claim 1 or 2.

4. The feed of claim 3, wherein the additive is present in the feed in a proportion of 0.01 to 0.06% by weight.

5. The feed of claim 4, wherein the additive is present in the feed in a proportion of 0.01 to 0.03% by weight.

6. Use of the additive according to claim 1 or 2, the feed according to any one of claims 3 to 5 for improving the eggshell quality of laying birds; preferably, the laying poultry is laying hens or laying ducks.

7. Use of the additive of claim 1 or 2 for the preparation of a feed or a medicament for the prevention or treatment of a disease caused by an infection with escherichia coli and/or salmonella.

8. Use of the additive of claim 1 or 2 for inhibiting the growth of escherichia coli and/or salmonella.

9. A feeding method of laying hens, which is characterized in that breeding hens or commercial laying hens are fed with the feed of any one of claims 3 to 5 for 3 to 5 weeks at the later stage of laying.

10. A pharmaceutical product comprising the additive of claim 1 or 2 and pharmaceutically acceptable auxiliary components.