RU2291709C1 - Immunoprophylaxis of calf viral respiratory diseases - Google Patents

Abstract

FIELD: veterinary, immunology.

SUBSTANCE: healthy calves are immunized three time with 10-day interval by hypodermic injection of immune serum from donor animal with hemagglutinin titer to infective rhinotracheitis virus of 1:256; to parainfluenza-3 virus of 1:1280; and to viral diarrhoea virus of 1:1024. After the first injection additionally probiotic preparation lactobifadol in amount of 16x10⁸ microbial bifido- cells and 2x10⁷ lactobacteria for 10 days in three courses.

EFFECT: nocifensor activation; decreased calf morbidity rate.

3 ex, 5 tbl

Description

The invention relates to veterinary immunology, relates to a method of immunization and can be used to prevent viral respiratory diseases of calves that occur as an associated viral infection of parainfluenza-3 (PG-3), infectious rhinotracheitis (IRT) and viral diarrhea-disease of the mucous membranes (VD-BS )

The rupture of the infectious chain and, if possible, the prevention of the transition of the epizootic process to a latent state is considered as the main principle of the fight against enzootia, one of the main tools of which is immunoprophylaxis. Immunoprophylaxis involves the creation of artificial immunity of the body by the introduction of biological preparations against the corresponding pathogen, while they distinguish between active (using vaccines and toxoids) and passive (using antibodies in the form of sera or globulin) immunization.

Known methods for the prevention of viral respiratory diseases of calves using monovalent (live and inactivated) or multivalent vaccines [1]. Known methods of immunization are based on complex measures, including intranasal vaccination of calves in the first weeks of life, their revaccination (parenterally) after 3-4 months, as well as vaccination of cows [2]. But with the complexity of the implementation of the known methods are ineffective, due to the presence in calves of colostral antibodies that block the antigens of the administered vaccines, thereby blocking the formation of immunity and exacerbating the infectious process. Live vaccines, in addition, have an immunosuppressive effect and can cause post-vaccination illness.

There is also known a method for the prevention of respiratory diseases of calves using the immune serum of animals-convalescents. The blood serum of animals-convalescents is a preparation containing antibodies to pathogens that form the virus-bacterial background of the livestock complex, however, the set of antibodies of blood serum of animals-convalescents and their titer do not always correspond to the complete set of antigenic structure of "local microflora", and in the manufacture of the drug and the complexity of the control does not ensure the stability and high quality of the finished forms, which reduces the effectiveness of therapeutic intervention using blood serum tnyh convalescent. In addition, the low varying activity of the blood serum of animals of convalescents requires mixing the sera of various donors with the use of the highest possible doses (at least 1.0 ml per 1 kg of live weight), which complicates the implementation of the known method.

As a preferred analogue, a method for the immunoprophylaxis of viral respiratory diseases of calves using the immune serum of animal donors is considered [3]. Treatment-and-prophylactic immune sera are obtained as a result of repeated massive injections of a specific antigen to provide an antibody level many times higher than that in convalescent serums; they quickly ensure the formation of passive immunity. However, due to the decay and disappearance of antibodies, passive immunity lasts a maximum of 2-3 weeks, which reduces the effectiveness of the use of therapeutic and prophylactic serums.

The purpose of the invention is to increase the effectiveness of the prevention of respiratory diseases of calves of viral and bacterial etiology.

This goal is achieved by using the probiotic lactobifadol in addition to passive immunization with the immune serum of animal donors.

Immune serum is prepared according to the method of N.I. Gorban (1981) from the blood of animal donors from the farm for which it is intended, previously tested for cattle leukemia virus in RID with negative results. Animals are immunized with a bivalent or trivalent vaccine. An effective serum should contain antibodies to the etiological agents of respiratory diseases of calves in the following credits: to the PG-3 virus - 1: 1280, to the IRT virus - 1: 256, to the VD-BS virus 1: 1024.

The probiotic lactobifadol is made from living bacteria of the species B. adolescentis and L. acidophilum by contact and sorption drying of biomass, which ensures a minimal change in its biological properties [4]. Both types of bacteria belong to the genera of the intestinal resident microflora of the animal body that dominates in number and physiological significance, have pronounced antagonistic activity against putrefactive, pathogenic and conditionally pathogenic microflora, which, in addition to the synthesis of antibiotic substances, hydrogen peroxide, lysozyme, interferon, interleukin, is competitive erythrocyte adhesion and immunomodulatory effects.

The method is as follows.

Calves of 15-20 days of age are immunized three times with an interval of 10 days by subcutaneous injection of serum of animal donors containing anti-hemagglutinins in titers for the IRT virus 1: 256, the PG-3 virus 1: 1280, the VD-BS virus 1: 1024, and additionally three times after the first injection of serum of animal donors for 10 days, lactobifadol is administered orally at a dose of 16 × 10 ⁸ microbial cells of bifidobacteria and 2 × 10 ⁷ microbial cells of lactobacilli.

The effectiveness of the method of immunological prophylaxis of viral respiratory diseases of calves by a combination of subcutaneous injection of animal donor serum with hemagglutinin titers to the IRT virus 1: 256, the PG-3 virus 1: 1280 and the VD-BS virus 1: 1024 and the use of lactobifadol inside was determined in the farms of the Nizhny Novgorod region stationary in respiratory disease calves of viral and bacterial etiology with an incidence of up to 60%. The etiological role of the viruses IRT, PG-3 and VD-BS was confirmed by their isolation in the serum of calves of virus-neutralizing antibodies to these viruses in 77.5, 87.5 and 85.7% of cases, respectively. Bacterial microflora was represented by streptococci, salmonella and proteins.

The essence of the method is illustrated by examples.

Example 1. The dose-dependent effect of lactobifadol was studied on 4 groups of clinically healthy calves 15-20 days of age, formed on the basis of analogues contained in the same conditions and on the same diets. Calves of all groups were immunized three times with an interval of 10 days by subcutaneous injection of serum of animal donors with hemagglutinin titers to the IRT virus 1: 256, the PG-3 virus 1: 1280 and the VD-BS virus 1: 1024 at a dose of 1 ml / kg live mass, and the calves of the first three groups after the first injection of serum were additionally used inside with lactobifadol in three courses lasting 10 days from the calculation of microbial cells: 12 × 10 ⁸ and 15 × 10 ⁶ , 16 × 10 ⁸ and 2 × 10 ⁷ , 2 × 10 ⁹ and 25 × 10 ⁶ bifidobacteria and lactobacilli, respectively. Calves were monitored for 60 days. The clinical condition of the animals was taken into account daily. Before and after the experiment, calves were weighed, blood was taken for immunological studies. The immune status was assessed by indicators of lysozyme activity of blood serum (determined by V.G. Dorofeychuk), bactericidal activity of blood serum (determined by O.V.Smirnova and T.A. Kuzmina), phagocytic activity of blood neutrophils (determined by A.N. Mayansky) and β-lysine activity of blood serum (determined by O.V. Bukharin). The results are presented in tables 1 and 2.

Table 1 The effectiveness of prevention depending on the dose of lactobifadol INDICATORS Groups of animals 1st experimental n = 10 2nd experimental n = 10 3rd experienced n = 10 4th control n = 10 Dose of lactobifadol, microbial cells - bifidobacteria 12 × 10 ⁸ 16 × 10 ⁸ 2 × 10 ⁹ lactobacilli 15 × 10 ⁶ 2 × 10 ⁷ 25 × 10 ⁶ Ill, goal. (%) 2 (20) 1 (10) 1 (10) 4 (40) The form of the disease, goal. (%) - light 1 (50) 1 (100) 1 (100) 2 (50) - heavy 1 (50) 2 (50) Palo, goal (%) 1 (10) - - 1 (10) Forced killed goal. (%) - - - 1 (10) Preventive efficacy,% 80 90 90 60 Preservation,% 90 one hundred one hundred 80 The average daily weight gain, g 768.3 ± 42.8 939.3 ± 30.6 964.0 ± 33.5 639.4 ± 71.6

table 2 Dose-dependent effect of lactobifadol on immunological parameters INDICATORS Calf groups 1st experimental n = 10 2nd experimental n = 10 3rd experienced n = 10 4th control n = 10 Bactericidal activity of blood serum,%

Dose of lactobifadol, microbial cells - bifidobacteria 12 × 10 ⁸ 16 × 10 ⁸ 2 × 10 ⁹ lactobacilli 15 × 10 ⁶ 2 × 10 ⁷ 25 × 10 ⁶ Lysozyme activity of blood serum,%

β-lysine activity of blood serum,%

Functional activity of blood neutrophils,% - spontaneous test

- induced test

Note: numerator - indicators before the start of the experiment, denominator - indicators 5 days after the end of the experiment

As can be seen from tables 1 and 2, with the tested doses, stable results were obtained. As an optimal dose for practical use, we can recommend a dose based on 16 × 10 ⁸ microbial cells of bifidobacteria and 2 × 10 ⁷ microbial cells of lactobacilli per head, which ensured maximum performance in relation to control and dose constraints. Boundary doses provide an increase in performance relative to control, but are not economically feasible.

Example 2. Prophylactic effectiveness depending on the duration of the course of lactobifadol was determined on 4 groups of clinically healthy calves 15-20 days of age, formed according to the principle of analogues kept in the same conditions and on the same rations. Calves of all groups were immunized three times with an interval of 10 days by subcutaneous injection of serum of animal donors with hemagglutinin titers to the IRT virus 1: 256, the PG-3 virus 1: 1280 and the VD-BS virus 1: 1024 at a dose of 1 ml / kg live mass, and the calves of the first three groups after the first injection of serum were additionally used inside with lactobifadol at a dose of 16 × 10 ⁸ microbial bifidobacteria and 2 × 10 ⁷ lactobacilli per head in three courses lasting 5, 10 and 15 days, respectively. Clinical observations of animals were carried out for 60 days after the end of the experiments. Accounting for the results of the experiment, as in example 1. The results are presented in tables 3 and 4.

As can be seen from tables 3 and 4, the course of using lactobifadol lasting 10 days was economically justified, providing maximum performance relative to the minimum course duration (5 days) and control. An increase in the duration of the course of lactobifadol administration to 15 days did not lead to a significant increase in the indicators relative to the selected duration of the course of lactobifadol administration in 10 days.

Table 3 The effectiveness of prevention, depending on the duration of the course of lactobifadol INDICATORS Groups of animals 1st experimental n = 10 2nd experimental n = 10 3rd experienced n = 10 4th control n = 10 The duration of the course of lactobifadol, days 5 10 fifteen Ill, goal. (%) 3 (30) 1 (10) 1 (10) 3 (30) The form of the disease, goal. (%) - light 3 (100) 1 (100) 1 (100) 2 (66.7) - heavy 1 (33.3) Palo, goal (%) - - - - Forced killed, goal. (%) 1 (33.3) - - 2 (66.7) Preventive efficacy,% 70 90 90 70 Preservation,% 90 one hundred one hundred 80 The average daily weight gain, g 772.0 ± 42.8 952.3 ± 30.6 959.3 ± 40.8 631.3 ± 46.9

Table 4 Immunological parameters depending on the duration of the course of lactobifadol INDICATORS Calf groups 1st experimental n = 10 2nd experimental n = 10 3rd experienced n = 10 4th control n = 10 Bactericidal activity of blood serum,%

Lysozyme activity of blood serum,%

β-lysine activity of blood serum,%

Functional activity of blood neutrophils,% - spontaneous test

- induced test

Note: numerator - indicators before the start of the experiment, denominator - indicators 5 days after the end of the experiment

Example 3. The comparative effectiveness of the claimed and known methods for the prevention of viral respiratory diseases of calves was determined in the conditions of the economy, long-term unfavorable for viral respiratory diseases, in 4 groups of healthy calves 20-30 days of age, selected by the principle of analogues. The calves were immunized in 4 ways: the first method (claimed) - serum of animal donors with hemagglutinin titers to the IRT virus 1: 256, the PG-3 virus 1: 1280 and the VD-BS virus 1: 1024 + lactobifadol in a dose of calculation of 16 × 10 ⁷ microbial cells of bifidobacteria and 2 × 10 ^{7 of} lactobacilli, the 2nd method (basic) - the vaccine "TRIVAC", the 3rd method (basic) - the vaccine "BIVAC", the 4th method (prototype) - serum of animal donors with hemagglutinin titers for the IRT virus 1: 256, for the PG-3 virus 1: 1280 and for the VD-BS virus 1: 1024. The calves were monitored taking into account the course of the disease and its outcome. Accounting for the results, as in example 1. The results are presented in table 5.

Table 5 The comparative effectiveness of the claimed and known methods of immunization of viral respiratory diseases of calves INDICATORS Groups of animals 1st n = 20 2nd n = 27 3rd n = 24 4th n = 20 Immunization method Serum + Lactobifadol TRIVAC vaccine BIVAC vaccine Serum Ill, goal. (%) 1 (5.0) 3 (11.1) 2 (8.3) 6 (30) The form of the disease, goal. (%) - light one 1 (33.3) 1 (50) 4 (66.7) - heavy 2 (66.7) 1 (50) 2 (33.3) Palo, goal (%) - - - - Forced killed, goal. (%) 1 (3.7) 1 (4.1) 2 (33.3) Preventive efficacy,% 95 88.9 90 70 Preservation,% one hundred 96.3 95.9 90

As can be seen from table 5, the claimed method provided an optimal prophylactic effect compared with known methods, which was expressed in a decrease in the number of diseased calves and a milder form of the disease.

A decrease in the incidence rate indicated an increase in resistance, which indicated an increase in the adaptive level. After recovery, the calves of the experimental groups developed well.

Obtained under long-term virus carrier conditions, i.e. immunological pressure, clinical data confirmed the achievement of the claimed technical result - an increase in prophylactic effectiveness by activation of protective mechanisms in all recorded parameters. The proposed combination can significantly reduce side effects, provides immunocorrection of key broken links of the immune system and increase the body's natural resistance.

Information sources

1. Urban V.P., Naimanov I.L. Diseases of young animals in industrial livestock. - M .: Kolos, 1984. - S.192-196.

2. Infectious diseases of animals. Reference / Comp. Yu.F. Borisovich, L.V. Kirillov; under the editorship of D.F. Ozidze. - M.: Agropromizdat, 1987 - S.99.

3. Immunoprophylaxis of animal diseases Per. with him. N.B. Chernykh - M .: Kolos, 1981. - S.274-277.

4. M.A. Sidorov, V.V. Subbotin, N.V. Danilevskaya. Normal microflora of animals and its correction with probiotics // Veterinary medicine. - 2000. - No. 11. - S.17-22.

Claims (1)

Method for the immunoprophylaxis of viral respiratory diseases of calves, comprising immunization with a polyvalent immune serum against infectious rhinotracheitis, parainfluenza-3 and viral diarrhea - a mucosal disease, characterized in that calves are immunized with serum immunoglobulins with titers of hemagglutinins to the virus of infectious rhinotracheitis virus 1: 256, - 1: 1280 and to the virus of viral diarrhea - mucosal disease - 1: 1024, which is injected subcutaneously three times with an interval of 10 days, and after the first injection in three courses lasting 10 days they use the probiotic preparation lactobifadol at the rate of 16 × 10 ⁸ microbial cells of bifidobacteria and 2 × 10 ^{7 of} lactobacilli.