RU2181283C2 - Method for preventing reproductive- respiratory syndrome in swine - Google Patents

Abstract

FIELD: veterinary medicine. SUBSTANCE: the method deals with injecting for sows a prophylactic preparation containing (weight%): formaldehyde 0.03-0.12, sodium chloride 0.9-0.95, distilled water - the rest. Moreover, the preparation suggested is injected at 4-6 ml/sow dosage twice or thrice at 7-10 d interval at the last injection of preparation 7-10 d before furrowing. To eliminate reinfecting in neonatal piglets or superinfecting in milking sows it is necessary to conduct additional treatment of piglets within 24-48 h after their birth. EFFECT: increased efficiency in preventing reproductive- respiratory syndrome in unsuccessful farms in piglets during neonatal and milking periods. 1 cl, 3 ex, 3 tbl

Description

 The invention relates to the field of veterinary medicine and can be used during preventive measures of reproductive and respiratory syndrome of pigs (PRRS).

 Reproductive and respiratory syndrome of pigs (synonyms - “blue ear”, late epizootic abortion of pigs) is a contagious disease caused by an RNA-containing virus, the toga-virus family. The disease is characterized by mass abortions in sows at the last stage of gestation, premature birth, the birth of a non-viable offspring, piglets with deformities, and is also accompanied by signs of respiratory damage.

 There is a known method of preventing PRRS (see the Temporary instruction "On measures for the prevention and control of reproductive and respiratory syndrome of pigs." - Approved by the Head of the Department of Veterinary Medicine and the Russian Federation on 02.03.94, 19-4-2 / 46), which consists in controlling number of pigs by banning the import and export of animals beyond the focus of infection, slaughter and rearrangement of pigs on the farm, as well as by controlling slaughter products by disinfecting meat and processing bones and offal of the second category for meat and bone meat y.

 However, this method is ineffective, because it does not completely get rid of the disease.

 There is also a known method of preventing PRRS (see "Temporary guidance on the use of dry culture virus vaccine." - Approved by the Department of Veterinary Medicine 12/18/98, 13-4-2 / 1458), which consists in the introduction of a vaccine from an attenuated strain of DB to pigs aged 34-40 days in a dose of 2 ml per head.

 However, this method is intended for the prevention of PRRS in pigs of weaning age and does not solve the problem of the safety of animals in the suckling period.

 Closest to the claimed is a method of preventing PRRS (see "Temporary guidance on the use of vaccines inactivated emulsion inactivated against PRRS." - Approved by the Department of Veterinary Medicine 04.02.97, 13-4-2 / 848), which consists in the introduction of inactivated vaccines to sows, pigs and boars-producers twice with an interval of 15-20 days three weeks before breeding. The vaccine is administered intramuscularly in a dose of 2 ml per head, regardless of the age of the animals.

 However, the effectiveness of preventive measures is small, since the effect of vaccination appears only after 5-6 months. In addition, the prevention of the disease is based on the introduction of the virus, which, in turn, can provoke an infectious process in naturally infected animals.

 The invention is aimed at solving the problem of increasing the effectiveness of PRRS prevention in dysfunctional farms in piglets in the prenatal and lactating periods.

 To solve the problem in the method for the prevention of reproductive and respiratory syndrome of pigs, which consists in administering to the sows an intramuscularly prophylactic preparation, a prophylactic preparation according to the invention is used containing, in wt.%: Formaldehyde - 0.03-0.12, sodium chloride - 0 , 9-0.95, distilled water - the rest, while the drug is administered in a dose of 4-6 ml per head 2-3 times with an interval of 7-10 days with the last injection of the drug 7-10 days before farrowing.

 To eliminate reinfection of newborn piglets or superinfection of lactating sows, additional treatment of piglets is carried out in the period from 24 to 48 hours after birth.

 The sources of patent and scientific and technical information known to the authors do not describe a PRRS prophylaxis method that can effectively carry out preventive measures in dysfunctional farms in piglets in the prenatal and lactating periods due to the use of a formaldehyde-containing sodium chloride and distilled water as a prophylactic.

 It is known to use a preparation containing formaldehyde, sodium chloride and distilled water as an immunomodulating agent (see RF patent 2077882, class MKI A 61 K 31/115, publ. 04/27/97).

 The effect of the drug is based on its ability to regulate the body's natural resistance.

 The claimed solution revealed a new property of the drug - to participate in the formation of specific immunity without the use of standard means of specific prevention. The action of the drug is based on the ability to form immune complexes on the surface of red blood cells, leading to the activation of specific immunity in both adult animals and fetuses during fetal development.

 It is known that in sows there is a placental barrier that does not allow the protection of piglets in the prenatal period from exposure to the virus with specific antibodies.

 Existing prevention systems are based on exposure to sows only until fertilization of the eggs and does not protect the fetus from exposure to PRRS virus in the prenatal period.

 The claimed invention allowed to solve the problem of preventing PRRS disease in dysfunctional farms in piglets in the prenatal and lactating periods by overcoming the placental barrier with specific antibodies formed as a result of the formed immune complexes on the surface of red blood cells.

 The foregoing allows us to conclude that there is an "Inventive step" in the claimed solution.

 The method is as follows.

 As a prophylactic drug, a preparation containing, by weight, is used. %: formaldehyde - 0.03-0.12, sodium chloride - 0.9-0.95, distilled water - the rest.

 The prophylactic drug is administered intramuscularly to sows in a dose of 4-6 ml 2-3 times with an interval of 7-10 days with the last administration of the drug 7-10 days before farrowing.

 Example 1. The rationale for the concentration of formaldehyde in the drug.

 To justify the concentration of formaldehyde in the preparation, groups of animals were formed (experimental and control). The first group was administered a drug with a formaldehyde concentration of 0.03%, the second - 0.08%, the third - 0.12%.

 In all groups, the introduction was carried out three times with an interval of 7-10 days.

 Animals of the control groups were injected only with physiological saline.

 The research results are presented in table 1, from which it follows that in the indicated concentrations the use of the drug is acceptable.

 Example 2. The rationale for the frequency of administration of the drug.

 To justify the multiplicity of drug administration, experimental and control groups of animals from the number of pregnant sows were formed. The drug was administered 1 time to the first experimental group, 2 times to the second and 3 times. The interval between injections was 7-10 days. The animals of the control groups were injected with saline in a similar manner.

 The research results are presented in table 2, from which it follows that the most effective three-time administration of the drug, in which stillbirth is 6.7%. The average rate of stillbirth in the control groups of animals was 52.9% (not shown in the table).

 Studies have been conducted on a four-time administration of the drug.

 It has been experimentally confirmed that such an introduction does not lead to the achievement of the desired result, but only to an increase in the cost of work.

 Example 3. The rationale for the timing of the last to farrowing the introduction of the drug 7-10 days.

 To prove the need for the last administration of the drug 7-10 days before farrowing, 3 experimental groups of animals and control groups were formed.

 The first experimental group of animals, the last administration of the drug was carried out 7-10 days before farrowing, the second - for 12-20 days, the third - for 21-30 days.

 At the same time, physiological saline was administered to animals in the control groups.

 The research results are presented in table 3, from which it follows that the most effective last administration of the drug 7-10 days before farrowing.

 Moreover, in each of the formed control groups, the average rate of stillbirth was about 40% (not shown in the table).

 The dose of the drug - 4-6 ml per animal - was selected experimentally. To use the drug in a dose of more than 6 ml is not economically feasible, and in a dose of less than 4 ml does not lead to the achievement of the goal, i.e. does not provide PRRS prophylaxis.

 The use of the drug with an interval of 7-10 days is due to the peculiarities of the immunological rearrangement of the animal organism, as well as the effectiveness of achieving the task.

 It is experimentally proved that the additional administration of the drug to piglets at a dose of 1-3 ml after 24-48 hours after birth eliminates the reinfection of newborn piglets.

 Thus, the claimed method allows to increase the effectiveness of PRRS prophylaxis in dysfunctional farms in piglets in the prenatal and lactating periods.

Claims (2)

 1. A method for the prevention of reproductive and respiratory syndrome of pigs, which consists in the intramuscular injection of a prophylactic drug, characterized in that as a prophylactic drug using a drug containing, by weight. %: formaldehyde 0.03-0.12, sodium chloride 0.9-0.95, distilled water - the rest, while the drug is administered in a dose of 4-6 ml 2-3 times with an interval of 7-10 days with the last injection 7-10 days before farrowing.  2. The method according to p. 1, characterized in that the drug is additionally administered to the piglets once intramuscularly at a dose of 1-3 ml after 24-48 hours after birth.

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