CN111330001B

CN111330001B - Suspending agent and suspension of rabbit coccidiosis attenuated live vaccine

Info

Publication number: CN111330001B
Application number: CN202010213328.7A
Authority: CN
Inventors: 刘贤勇; 索勋; 邓梦青; 胡丹丹; 成霞; 罗光琴; 索静霞; 汤新明
Original assignee: China Agricultural University
Current assignee: China Agricultural University
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2022-05-20
Anticipated expiration: 2040-03-24
Also published as: CN111330001A

Abstract

The invention relates to veterinary parasitology and immunobiology, in particular to a suspending agent and suspension of a rabbit coccidiosis attenuated live vaccine. The rabbit coccidiosis attenuated live vaccine suspending agent comprises a suspending complex agent with the mass fraction of 0.15-0.3 per mill, wherein the suspending complex agent is prepared from the following components in percentage by mass of 1: (0.8-1.2) pectin and xanthan gum. The rabbit coccidiosis attenuated live vaccine suspending agent can realize the immunization of rabbits in a drinking water mode, and in addition, the suspending agent has high dissolving speed at normal temperature, can ensure that rabbit coccidiosis oocysts form a uniformly dispersed system in water and do not sink for more than 6 hours, ensures the immunization uniformity of the rabbit coccidiosis attenuated live vaccine, and provides powerful technical support for the popularization and application of the rabbit coccidiosis attenuated live vaccine in the practical production.

Description

Suspending agent and suspension of rabbit coccidiosis attenuated live vaccine

Technical Field

The invention relates to veterinary parasitology and immunobiology, in particular to a suspending agent and suspension of a rabbit coccidiosis attenuated live vaccine.

Background

Coccidiosis of rabbit is parasitic disease caused by Eimeria coccidian parasitizing in bile duct or intestinal tract, and is classified as four big rabbit diseases together with rabbit plague, rabbit pasteurellosis and rabbit sarcoptidosis. Among them, rabbit coccidiosis is the most common and most harmful parasitic disease. The variety of rabbit Eimeria coccidia is various, 11 types are internationally accepted at present, the main popular types in China are large-sized Eimeria (Eimeria magna), medium-sized Eimeria (Eimeria media), intestinal Eimeria (Eimeria intestinalis) and the like, and various types of rabbits are susceptible to Eimeria coccidia and are most susceptible to rabbits with the age of 1-4 months. The death rate of the young rabbits is high after infection, the young rabbits become a long-term insect carrier after being endured, oocysts are continuously discharged into the environment, equipment such as cages, troughs, drinking water and the like are polluted, and the young rabbits are infected. This circulation is an important reason why rabbit coccidiosis cannot be effectively controlled.

While animal epidemic disease can restrict the development of rabbit industry, as mentioned above, rabbit coccidiosis is one of the main problems to be solved urgently. Since no relevant vaccine is on the market at present, only anticoccidial drugs are relied on for prevention. However, the use of the drug brings many negative effects, such as drug residue in animal food, the occurrence of drug-resistant insect strains and the like. Therefore, a safer and more effective method for preventing and controlling rabbit coccidiosis is urgently needed in actual breeding.

The great success of coccidiosis vaccines in the field of coccidiosis prevention and control of chickens suggests that the use of live oocyst vaccines is the best means for preventing coccidiosis. At present, some rabbit coccidian attenuated live vaccines with good safety and effectiveness exist in the field, and good immune effects can be achieved by inoculating the rabbit coccidian attenuated live vaccines. However, when the immunization mode of the vaccination is applied to actual cultivation, a large amount of time resources and human resources are needed, which is not beneficial to controlling the production cost.

In contrast, the drinking water immunization method is the best method for the immunization of the large-scale farm at the present stage, and is suitable for the requirements of complex feeding environment and production conditions. However, because the density of the oocysts is higher than that of water, the oocysts in the vaccine easily sink after standing for a long time, and the uniform distribution of the oocysts in the water is influenced, so that the vaccine is not immunized uniformly, and the immunization fails.

The existing coccidiosis vaccine mainly comprises one or more of Eimeria tenella, Eimeria acervulina, Eimeria maxima and Eimeria necatrix precocious strain, and the average size of oocysts is 22 Mum × 19 μm, 18 Mum × 15 μm, 31 Mum × 21 μm and 20 Mum × 17 μm respectively. The life history of the rabbit coccidia is similar to that of the chicken coccidia, but the oocyst size of the rabbit coccidia is different. For example, the average size of large Eimeria oocysts in a rabbit coccidiosis attenuated live vaccine is 37.3 microns multiplied by 24.1 microns, the average size of medium Eimeria is 25.4 microns multiplied by 15.3 microns, and the average size of Eimeria enterocolitica is 27 microns multiplied by 18 microns, so when the coccidiosis vaccine suspending agent applied to chickens in the prior art is applied to the rabbit coccidiosis attenuated live vaccine, the suspending agent suitable for the suspending rabbit coccidiosis attenuated live vaccine needs to be prepared according to the oocyst characteristics of different rabbits in terms of different coccidiosis oocysts due to different sizes and densities of oocysts and certain difference in suspension stability. Meanwhile, the existing coccidian vaccine suspending agent applied to the chicken is relatively complex in components and high in required production cost. In addition, the existing suspending agent applied to chicken also has the problem of poor solubility of the suspending agent, and as most of colloids are relatively insoluble, a great deal of time is wasted for dissolving the suspending agent in production and application.

Disclosure of Invention

Technical problem to be solved

In order to find a proper suspending agent, the coccidiosis vaccine is prepared into a stable suspension, the drinking time of rabbits is prolonged, the stress response of the rabbits is reduced, and the uniform and effective coccidiosis immune protection is obtained.

(II) technical scheme

In a first aspect, the invention provides a suspending agent for a live attenuated rabbit coccidiosis vaccine, which comprises a suspending complex agent with a mass fraction of 0.15-0.3 per mill (more preferably 0.25 per mill), wherein the suspending complex agent is prepared from the following components in a mass ratio of 1: (0.8-1.2) pectin and xanthan gum.

The suspending agent can maintain the suspension state of vaccine oocysts in a vaccine solution, does not have adverse effects on the yield of oocysts and sporozoites, is nontoxic to rabbits, and is an ideal suspending agent for the rabbit coccidiosis attenuated live vaccine.

Preferably, the mass ratio of the pectin to the xanthan gum is 1: 1.

the invention further discovers that the KCl with a certain concentration can increase the dissolution speed while not influencing the effectiveness of the suspending agent, and preferably, the suspending agent for the rabbit coccidiosis attenuated live vaccine also contains KCl with the mass fraction of 0.6-1.2% (more preferably 1.0%).

In addition, the invention also tries to use the material blowing powder in CN200510036004.6 and the heating method in CN201210231082.1 in the development process, which can not lead pectin and xanthan gum to be dissolved quickly.

Preferably, the pectin, xanthan gum and KCl are all food grade.

Of course, other materials (such as water) used in the rabbit coccidiosis attenuated live vaccine suspending agent should also be food grade or pharmaceutical grade.

In some embodiments, the rabbit coccidiosis attenuated live vaccine suspending agent is prepared by the following steps: mixing pectin, xanthan gum and KCl in parts by mass with water, and stirring.

In a second aspect, the invention provides a suspension of a live attenuated rabbit coccidiosis vaccine, which comprises the live attenuated rabbit coccidiosis vaccine and a suspending agent of the live attenuated rabbit coccidiosis vaccine.

Preferably, when the preparation raw materials of the rabbit coccidiosis attenuated live vaccine are precocious systems of large Eimeria, medium Eimeria and Eimeria intestinalis, the rabbit coccidiosis attenuated live vaccine suspending agent has a better compounding effect, and has good safety and immune effect when being applied to rabbits.

More preferably, the raw materials for preparing the rabbit coccidiosis attenuated live vaccine comprise sporulated oocysts of the precocious lineage strains of Eimeria, Eimeria intermedia and Eimeria intestinalis.

Preferably, the rabbit coccidiosis attenuated live vaccine is prepared by separating, purifying and sporulating coccidian oocysts.

As a preferred scheme, the preparation process of the rabbit coccidiosis attenuated live vaccine comprises the following steps: the large Eimeria, medium Eimeria and precocious system of Eimeria intestinalis are prepared by separating, purifying and sporulating oocysts of Eimeria, and mixing the oocysts and the oocysts according to a certain proportion.

Preferably, in the rabbit coccidiosis attenuated live vaccine, 100-3000 oocysts per head of large Eimeria praecox attenuated strain, 500-5000 oocysts per head of Eimeria enteric attenuated strain, and 500-6000 oocysts per head of medium Eimeria praecox attenuated strain.

Preferably, in the suspension of the rabbit coccidiosis attenuated live vaccine, the dosage of the rabbit coccidiosis attenuated live vaccine is 50-80ml of suspension per head part of vaccine (the immunization time can be properly adjusted according to 6h without causing stress to rabbit groups, and the corresponding drinking amount is also adjusted).

For example, in a certain farm, 2000 rabbits (assuming that the day-old of the rabbits is 30 days old and the water intake of each rabbit is about 10ml/h) are placed in a rabbit house, and the water intake is about 120L after immunization for 6 h. After the suspending agent is added according to the drinking water amount, 2000 parts of vaccine is added into the suspension and stirred evenly.

In a third aspect, the invention provides an orally ingestible live attenuated rabbit coccidiosis vaccine product, comprising the live attenuated rabbit coccidiosis vaccine suspension and a pharmaceutically acceptable adjuvant thereof.

The young rabbits are generally fed by breast milk, so the method for immunizing the young rabbits by drinking water has limitation, and the suspending agent can uniformly disperse oocysts in a system, so the suspending agent can be used for drinking water immunization and can also be used for spray immunization to solve the coccidiosis prevention immunization of rabbits at different ages. Because the modern large-scale breeding rabbit industry has a little difference according to the marketing time and the weaning time of the rabbits under the actual conditions, the spraying immunization of the drinking water of the pipeline drinking water cannot be adopted if the drinking water immunization of the active pipeline drinking water is adopted for the rabbit group.

In a fourth aspect, the invention provides the use of the rabbit coccidiosis attenuated live vaccine suspending agent or the rabbit coccidiosis attenuated live vaccine suspension or the orally ingestible rabbit coccidiosis attenuated live vaccine product in rabbit breeding.

The preferred embodiments can be combined by those skilled in the art to yield preferred embodiments of the invention.

(III) advantageous effects

The rabbit coccidiosis attenuated live vaccine suspending agent can realize the immunization of rabbits in a drinking water mode, and in addition, the suspending agent has high dissolving speed at normal temperature, can ensure that rabbit coccidiosis oocysts form a uniformly dispersed system in water and do not sink for more than 6 hours, ensures the immunization uniformity of the rabbit coccidiosis attenuated live vaccine, and provides powerful technical support for the popularization and application of the rabbit coccidiosis attenuated live vaccine in the practical production.

Drawings

FIG. 1 shows the results of the uniformity of oocyst distribution test of the live attenuated rabbit coccidiosis vaccine of Experimental example 1; wherein, the graphs a to f correspond to the results of the examples 1 to 3 and the comparative examples 1 to 3 in sequence;

FIG. 2 is a graph showing the statistical results of oocyst production and weight gain after immunization with live attenuated rabbit coccidiosis vaccine in Experimental example 3; wherein, the left graph is the statistical result of the yield of the oocysts, and the right graph is the result of weight gain;

FIG. 3 is a statistical result of oocyst yields before and after challenge with live attenuated rabbit coccidiosis vaccine of Experimental example 4; wherein, the left graph is the yield of oocysts before challenge; right panel shows oocyst yield after challenge;

FIG. 4 shows the results of the immunological homogeneity of rabbit coccidiosis attenuated live vaccine before and after challenge in test example 4; wherein, the left graph shows the immune homogeneity before challenge; the right panel shows the immune homogeneity after challenge;

FIG. 5 shows the results of body weight changes before and after challenge with live attenuated rabbit coccidiosis vaccine of Experimental example 4; wherein, the left graph is the weight change result before attacking toxin; the right graph shows the body weight change after challenge;

FIG. 6 shows the results of the feed conversion rate before and after challenge for the rabbit coccidiosis attenuated live vaccine of test example 4; wherein, the left graph is the result of the feed conversion rate before the challenge; the right graph shows the feed conversion rate results after challenge;

FIG. 7 is a statistical result of oocyst production before and after challenge with live attenuated rabbit coccidiosis vaccine of Experimental example 5; wherein, the left graph is the yield of oocysts before challenge; right panel shows oocyst yield after challenge;

FIG. 8 shows the results of body weight changes before and after challenge with the live attenuated rabbit coccidiosis vaccine of Experimental example 5; wherein, the left graph is the weight change result before attacking toxin; the right panel shows the results of body weight changes after challenge.

Detailed Description

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

In the following embodiments, the suspending agent used is food grade, available commercially.

The preparation process of the rabbit coccidiosis attenuated live vaccine is as follows: the large Eimeria, medium Eimeria and Eimeria intestinalis precocity system is prepared by separating, purifying and sporulating coccidian oocysts, and mixing the separated and purified oocysts according to the proportion of 150 oocysts/head part of the precocious attenuated strain of the large Eimeria, 800 oocysts/head part of the precocious attenuated strain of the Eimeria intestinalis and 3000 oocysts/head part of the precocious attenuated strain of the medium Eimeria.

Wherein said E.macrogolea, E.mesogenes and E.intestinalis precocity is in accordance with the respective coccidia used in the embodiment of CN 110694058A.

The test animals were 30-day-old rabbits purchased from 28095Zhang Kogyo, Hebei province, and bred in a coccidian-free isolator.

The examples do not show the specific techniques or conditions, according to the technical or conditions described in the literature in the field, or according to the product specifications. The reagents or instruments used are conventional products available from regular distributors, not indicated by the manufacturer.

Example 1

The embodiment provides a suspending aid for a live attenuated rabbit coccidiosis vaccine, which comprises a suspending aid compound agent with the mass fraction of 0.2 per mill and KCl with the mass fraction of 1%, wherein the suspending aid compound agent comprises the following components in percentage by mass of 1: 1 pectin and xanthan gum.

The preparation method comprises the following steps: mixing pectin, xanthan gum and KCl in parts by mass with water, and stirring.

Example 2

This example provides a suspending agent for rabbit coccidiosis attenuated live vaccine, which is different from example 1 in that: the mass fraction of KCl is 0.8%.

Example 3

This example provides a suspending agent for rabbit coccidiosis attenuated live vaccine, which is different from example 1 in that: does not contain KCl.

Comparative example 1

The comparative example provides a rabbit coccidiosis attenuated live vaccine suspending agent, which is different from the suspending agent in example 1 in that: contains no pectin and no KCl.

Comparative example 2

The comparative example provides a rabbit coccidiosis attenuated live vaccine suspending agent, which is different from the suspending agent in example 1 in that: does not contain xanthan gum and KCl.

Comparative example 3

The comparative example provides a rabbit coccidiosis attenuated live vaccine suspending agent, which is different from the suspending agent in example 1 in that: pectin and xanthan gum are replaced by carboxymethyl cellulose with the same amount.

Test example 1 suspending agent to maintain vaccine oocysts in suspension in vaccine solution

The test steps are as follows: putting 1000ml of the suspending agent in the examples 1-3 and the comparative examples 1-3 into a 2L beaker, taking the rabbit coccidiosis attenuated live vaccine (400 ten thousand oocysts) by using a liquid transfer gun, adding the rabbit coccidiosis attenuated live vaccine (400 ten thousand oocysts) into the beaker, fully and uniformly stirring, respectively sucking 100 mu L of the coccidiosis vaccine mixed liquid into clean 1.5ml of centrifuge tubes at the positions of 1000 plus 8000, 6000 plus 4000 and 2000-0ml of the prepared coccidiosis vaccine mixed liquid (namely the upper layer, the middle layer and the lower layer of the vaccine mixed liquid) by using the liquid transfer gun after 0, 2, 4, 6 and 8 hours, respectively, adding 900 mu L of saturated physiological saline into each centrifuge tube, uniformly blowing by using the 1ml of liquid transfer gun, filling the liquid into a Mackester counting plate, calculating the number of oocysts under a 10-fold microscope, and taking 10 samples from each layer. The suspending effect of the oocysts after standing for different times is calculated and counted by taking 0 hour as a base number, and the result is shown in table 1.

TABLE 1 oocyst distribution uniformity test results

The results (see figure 1, wherein, a-f correspond to the results of examples 1-3 and comparative examples 1-3 in sequence) show that the vaccine oocysts do not float or sink within 6 hours in the examples 1-3 of the invention, the ratio of the number of the oocysts is within the range, the suspension requirement is met, and the suspension stability of the vaccine suspension is not influenced by adding KCl. However, example 3 the suspending agent dissolved much longer than in examples 1 and 2. The suspension stability of comparative examples 1, 2 and 3 was poor and did not meet the suspension requirements.

Experimental example 2 speed of dissolving suspending agent in water

In the modern intensive rabbit breeding industry, the breeding scale of a rabbit factory is generally large, and the working efficiency in any link of the rabbit factory can influence the benefit of the rabbit factory. It must be noted that, in the large-scale rabbit industry, as many as 2000 rabbits are raised in each rabbit hutch, the corresponding water consumption of the rabbits is large, and the addition of the suspending agent is large, so that a large amount of time is wasted on dissolving the suspending agent, and the application of the rabbit coccidiosis attenuated live vaccine in the actual production is influenced. Therefore, the suspending agent of the coccidian live oocyst vaccine must be quickly dissolved in the using process of the rabbit coccidian vaccine so as to meet the requirement of high-efficiency modern rabbit breeding production.

In this experimental example, the dissolution rates of the suspending agents of examples 1 to 3 were respectively tested, and the specific processes were as follows: the raw materials are weighed according to the mixture ratio in examples 1-3, added into a 2L beaker containing 1000ml of water at the same stirring speed, kept stand and the dissolution time is recorded, and the result is shown in Table 2 below.

TABLE 2

The result shows that the KCl can be added into the suspending agent to accelerate the dissolution speed, and the suspending agent can be immediately dissolved when the concentration of the KCl is 1%.

Experimental example 3 testing of the toxic Effect of suspending Agents on Rabbit coccidia sporozoites and on Rabbit bodies themselves

The rabbit coccidian oocysts have thicker oocyst walls and can resist stronger external pressure and harmful effects. However, when the oocysts enter the rabbit, sporozoites in the oocysts are released by the mechanical action of the stomach and by digestive enzymes in the intestinal tract. Sporozoites are fragile after losing the protection of the oocyst and sporocyst walls and may come into direct contact with suspending agents ingested by rabbits, which can potentially damage coccidial sporozoites. It is therefore essential to verify whether the suspending agent component is toxic to the rabbit coccidia sporozoites in the vaccine component.

The test steps are as follows: using 30-day-old rabbits, randomly dividing the rabbits into four groups according to the body weight, and using 3 rabbits in the 1 st group as a blank control group without inoculation; group 23 rabbits were inoculated orally; 3 rabbits in the group 3 were immunized with drinking water for 6 h; the 4 th group of 3 rabbits was inoculated with drinking water for 24h, and four groups of rabbits were kept in isolation under the same conditions and were inoculated after an adaptation period of 5 days. The following table 3 shows the water intake of rabbits about 30 days old monitored under the condition of a laboratory isolator:

TABLE 3 Rabbit Water intake situation

Namely, the water intake of each rabbit about 30 days old is about 10 ml/h. The influence of the water intake of the rabbits on the conditions such as air temperature, feed intake and the like is large, and the data is that the temperature is 26 ℃ under the condition of an isolator, the ventilation is good, and the data is measured under the condition of normal feed intake.

After the suspensions of the respective concentrations according to example 1 of the present invention were prepared in

groups

3 and 4, 181ml and 726ml of the suspensions were added with 3 vaccine portions for 6-hour and 24-hour drinking water immunization, respectively. The incubation periods of the early-maturing strains are respectively: e.magna 96h (4d), E.media72h (3d) and E.intestinal132h (5.5d), collecting 3-14d of excrement after immunization according to the incubation period of the early-maturing strain, counting oocysts, determining the effective inoculation dose, weighing the rabbits before and 14d after inoculation, and determining the weight increment condition after immunization. The immunization regimen is as follows in table 4:

TABLE 4 immunization regimen

The statistical result of the oocyst yield and the weight gain result after the immunization of the live attenuated rabbit coccidiosis vaccine are shown in figure 2; wherein, the left graph is the statistical result of the oocyst yield, and the right graph is the weight gain result. The result shows that the addition of the suspending agent in the invention does not influence the yield of oocysts, namely the suspending agent does not have toxic action on the sporozoites; the weight gain of rabbits has no obvious change, i.e. the intake of the suspending agent does not produce toxic action on rabbits. Therefore, the drinking water immunization of the rabbit coccidiosis attenuated live vaccine by using the suspending agent does not influence the immune effect of the vaccine and the growth health of rabbits.

Test example 4 Drinking Water immunization

In order to explore the application effect of the vaccine suspending agent in the actual production, the rabbit is immunized by drinking water.

The test steps are as follows: 150 rabbits of 30 days old are randomly divided into 5 groups according to body weight, and 30 rabbits in the 1 st group are not inoculated as a blank control group; group 2 30 rabbits were inoculated orally;

group

3, 30 rabbits were vaccinated with drinking water for 6h (group 3 and group 4 had separate waterlines, and rabbits were randomly examined for 5 positions, respectively); the 4 th group of 30 rabbits was immunized with drinking water for 6 hours (no suspending agent was added), and the 5 th group of 30 rabbits was not immunized but only detoxified. Inoculation was performed after an acclimation period of 5 days. Challenge was carried out 14 days after immunization, and each rabbit was orally inoculated with 1 ten thousand oocysts each of large Eimeria, medium Eimeria, and E.coli wild strains.

Group 3, after preparing suspensions with corresponding concentrations according to example 1 of the present invention, 1.8L of the suspension was added with 30 parts of vaccine for 6h mini-drinking immunization, group 4, 1.8L of water was added directly with 30 parts of vaccine without suspending agent for 6h mini-drinking immunization, the incubation period of wild plants: e.magna 120h (5 d); e.media108h (4.5 d); interest 204h (8.5 d). Collecting oocysts 3-14d after immunization according to the incubation period of the early-maturing strain, and determining the effective inoculation dose; and (4) collecting the number of oocysts 4-14d after challenge according to the incubation period of the wild strain to determine the protective effect of the vaccine. The feasibility of drinking water immunization modes was determined by comparing the oocyst yield, immune homogeneity, weight change, feed conversion rate, survival rate and mortality after inoculation and challenge. The immunization regimen is as follows in table 5:

TABLE 5 Drinking immunization

The statistical results of the oocyst yield before and after challenge of the rabbit coccidiosis attenuated live vaccine are shown in figure 3, the immune uniformity result is shown in figure 4, the weight change result is shown in figure 5, and the feed conversion rate result is shown in figure 6; in FIGS. 3 to 6, the left graph shows the results before challenge, and the right graph shows the results after challenge; the survival and mortality rates are shown in table 6. The result shows that compared with the drinking water immunity of the group without the suspending agent, the drinking water immunity of the group with the suspending agent has better effect and better immunity uniformity. Since drinking water immunization experiments were not in isolators, but in an open large environment, the blank group also presented with coccidial infections.

TABLE 6 survival and mortality

Test example 5 spray immunization

As the young rabbits can not be immunized by maternal antibodies after the immunization of the female rabbits, the young rabbits also need to be immunized, and the experiments prove that the young rabbits before 20 days old are not susceptible to coccidiosis, but the rabbits at 30 days old are completely susceptible, so the preventive immunity of the young rabbits should be between 20 and 30 days old, and the immunization of the vaccine is influenced by the poor susceptibility of the young rabbits with too small day old, so the experiment selects the young rabbits at 25 days old for immunization.

The test steps are as follows: the 25-day-old young rabbits have 4 litters (8 litters), and each litter is 1 group. Group 1 was used as a blank, group 2 was spray immunized, group 3 was directly orally drenched, and group 4 was not only challenged. Feeding the rabbit in a coccidian-free isolator for 14 days after immunization for challenge, and inoculating 1 ten thousand oocysts of large Eimeria, medium Eimeria and Eimeria intestinalis wild strains respectively into each rabbit orally. Collecting the feces 3-14 days after the immunization of each group of rabbits and 4-14 days after the challenge to check the yield of oocysts and the weight change of each group of rabbits in the immunization and challenge processes. The effect of spray immunization was evaluated based on oocyst production and weight change. The immunization mode is shown in table 7, wherein the spray immunization refers to that 8 vaccine portions are added into 10ml of suspension aid, evenly mixed and sprayed on the surface of the padding for immunization.

TABLE 7 spray immunization

The results are shown in fig. 7-8, wherein fig. 7 is statistical results of oocyst yield before and after challenge, and fig. 8 is weight change results before and after challenge; in FIGS. 7 to 8, the left graph shows the results before challenge, and the right graph shows the results after challenge. The result shows that certain immune protection effect can be generated through spray immunization, and the method is simple to operate and has certain advantages for young rabbits which cannot be immunized through drinking water.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can 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. The rabbit coccidiosis attenuated live vaccine suspending agent is characterized by comprising 0.2 per mill of suspending complex agent, 0.8-1.0% of KCl and water in mass percentage, wherein the suspending complex agent comprises the following components in percentage by mass of 1: (0.8-1.2) pectin and xanthan gum.

2. The rabbit coccidiosis attenuated live vaccine suspending agent according to claim 1, wherein the pectin, xanthan gum and KCl are all food grade.

3. A suspension of live attenuated rabbit coccidiosis vaccine comprising live attenuated rabbit coccidiosis vaccine and the suspending agent of live attenuated rabbit coccidiosis vaccine as claimed in any one of claims 1-2.

4. The rabbit coccidiosis attenuated live vaccine suspension of claim 3, wherein the rabbit coccidiosis attenuated live vaccine is prepared from sporolated oocysts of precocious strains of Eimeria macrotype, Eimeria mesotype and Eimeria intestinalis.

5. The rabbit coccidiosis attenuated live vaccine suspension according to claim 3 or 4, wherein the rabbit coccidiosis attenuated live vaccine is prepared by separation, purification and sporulation of coccidian oocysts.

6. The rabbit coccidiosis attenuated live vaccine suspension according to claim 3 or 4, wherein in the rabbit coccidiosis attenuated live vaccine, 100-3000 oocysts per head of Eimeria macrolepis strain, 500-5000 oocysts per head of Eimeria enterocolitica strain, and 500-6000 oocysts per head of Eimeria mesomicturi strain.

7. The rabbit coccidiosis attenuated live vaccine suspension as claimed in claim 5, wherein in the rabbit coccidiosis attenuated live vaccine, 100-3000 oocysts per head of Eimeria macrolepis strain, 500-5000 oocysts per head of Eimeria enterocolis strain, and 500-6000 oocysts per head of Eimeria mesomicta strain.

8. The rabbit coccidiosis attenuated live vaccine suspension according to any one of claims 3, 4 and 7, wherein the rabbit coccidiosis attenuated live vaccine is used in an amount of 50-80ml per head vaccine.

9. The rabbit coccidiosis attenuated live vaccine suspension of claim 5, wherein the rabbit coccidiosis attenuated live vaccine is administered in an amount of 50-80ml suspension per head vaccine.

10. The rabbit coccidiosis attenuated live vaccine suspension of claim 6, wherein the rabbit coccidiosis attenuated live vaccine is administered in an amount of 50-80ml suspension per head vaccine.

11. An orally ingestible live rabbit coccidiosis attenuated vaccine product comprising the live rabbit coccidiosis attenuated vaccine suspension according to any one of claims 3 to 10 and a pharmaceutically acceptable adjuvant thereof.

12. Use of the rabbit coccidiosis attenuated live vaccine suspending agent of claim 1 or 2, or the rabbit coccidiosis attenuated live vaccine suspension of any one of claims 3 to 10, or the orally ingestible rabbit coccidiosis attenuated live vaccine product of claim 11, for the preparation of a medicament for breeding rabbits.