Polish primitive horses or the Polish Konik horse
Polish primitive horses are maintained under three different strategies: stabled (ST), free-ranging (FR) and semi-free (SF) management systems (Jezierski & Jaworski, 2008). The stabled system is traditional – the horses are kept and fed in stables or on small paddocks. In the free-ranging system, horses are kept in natural reserves as free ranging animals under nearly natural conditions without human care (Jaworski, 2007). The semi-free conditions are characterized by keeping the horses in large reserve areas, similarly to free-ranging conditions, but the horses are periodically in contact with people, moved onto small paddocks, and can be used for various types of work (Jezierski & Jaworski, 2006, 2008). Grazing is very important in all three management strategies and horses must spend most of their time on pastures or paddocks (Jaworski & Jaszczycska, 2004).
Worldwide, wild and domestic horses kept under different management strategies are infected with gastrointestinal parasites that cause significant problems to their health (Lichtenfels, 1975; Dvojnos & Kharchenko, 1994; Hodgkinson, 2006). Previous studies monitoring the gastrointestinal parasite community of Polish primitive horses from different reserves indicated high levels of infections with intestinal parasites, especially with strongylids, which without anthelmintic treatments reached infection levels estimated as thousands of eggs per gram of feces (Romaniuk
Several studies on the gastrointestinal parasites in the Polish primitive horses from different reserves in Poland were performed recently (Slivinska
Our study was carried out on nine farms with different types of management strategies from four regions of Poland (Fig. 1): the Warminsko-Mazurskie region – Popielno forest reserve (Popiel-no; 53°45′16.4″N; 21°37′42.1″E), Seven Island Lake Nature Reserve (Seven Island; 54°18’N 21°34’E), and a private ecological farm “Majdan” near Ruczane-Nida town (Majdan; 53°39′16″N 21°29′1″E); the Podlaskie region – the Bialowieza National Park (Bialowieza; 52°45′7.66″N 23°52′44.86″E), Biebrza National Park (Biebrza; 53°40′0”N, 22°46′0”E), Narew National Park (Narew; 53°03′00″N 22°24′15″E) and a private farm near Monki town (Monki; 53°24’N 22°48’E); Lubelskie region – Roztocze National Park (Roztocze; 50°21′55″N 22°34′48″E), and Lodzkie region – a breeding farm “Siriusz” near Lodz city (Siriusz; 51°47’N 19°28’E). Totally, 124 Polish primitive horses (96 females and 28 males) were included in this study during spring seasons in 2008 – 2012. According to the different types of management strategies, all horses were divided into three groups: 1) stabled horses (ST) (n=46); 2) semi-free horses (SF) (n=30), and 3) free-ranging horses (FR) (n=48). All horses examined were divided into three age groups: foals and horses less than 3 years old (n=53), horses from 3 to 10 years old (n=51) and old horses of more than 10 years old (n=20) (Table 1). All horses had natural levels of parasite infections and had not been treated with any anthelmintics at least for 3 month before the study began.
Locations of nine Polish primitive horse farms included into the study in Poland
Number of Polish primitive horses (n=124) examined of different age groups from nine horse farms in Poland
Farm | Location/Region | Types of horse management | Number of samples per age group | |||
---|---|---|---|---|---|---|
< 3 years | 3 – 10 years | >10 years | Total | |||
Popielno (1) | W-MR | ST | 11 | 7 | 4 | 22 |
Popielno (2) | W-MR | FR | 11 | 0 | 0 | 11 |
Seven Island | W-MR | FR | 9 | 2 | 0 | 11 |
Majdan | W-MR | SF | 1 | 6 | 7 | 14 |
Bialowieza | PR | SF | 1 | 3 | 2 | 6 |
Biebrza | PR | FR | 4 | 5 | 1 | 10 |
Narew | PR | SF | 0 | 2 | 0 | 2 |
Monki | PR | SF | 4 | 4 | 0 | 8 |
Roztocze (1) | LBR | FR | 7 | 4 | 5 | 16 |
Roztocze (2) | LBR | ST | 0 | 12 | 1 | 13 |
Siriusz | LR | ST | 4 | 7 | 0 | 11 |
Regions: W-M – Warminsko-Mazurskie region, PR – Podlaskie region, LBR – Lubelskie region, LR – Lodzkie region;
Types of horse management: ST – stabled horses, FR – free-ranging horses, SF – semi-free horses.
The level of horse infections with gastro-intestinal parasites was determined by the coprological McMaster technique with sensitivity of 25 eggs per gram of feces (EPG value) (Herd, 1992). Fresh fecal samples were collected
Gastrointestinal parasites (nematodes and cestodes) were collected from every individual horse
Primer 6 software (Clarke, Gorley, 2006) was used for statistical analysis. Taking into account that expulsion of parasites (eggs and adults) into feces is not normally distributed, statistical analysis was performed using the nonparametric Kruskal
Coprological examination of the Polish primitive horses showed that strongylid nematodes were the most prevalent parasites at all farms – 95.2 % of horses were infected with strongylids; eggs of
Prevalence (%) of infection with gastrointestinal parasites in Polish primitive horses (n=124) from nine farms in Poland: results of the fecal egg counts (EPG) and diagnostic deworming
Farm/ Number of horses | Fecal egg count data, prevalence/EPG (average) | Diagnostic deworming data, prevalence in % | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Strongylidae | Strongylidae | O. | G. | ||||||||||
Prev., % | EPG | Prev., % | EPG | Prev., % | EPG | Prev., % | No. of species | ||||||
Popielno, ST (22) | 100 | 1030.1 | 18.2 | 25.0 | 22.7 | 285 | 100 | 24 | 4.5 | 45.5 | 63.6 | 45.5 | |
Popielno, FR (11) | 100 | 684.1 | 63.6 | 28.6 | 27.3 | 250 | 100 | 25 | 63.6 | 100 | 18.2 | 72.7 | 90.9 |
Seven Isl., FR (11) | 100 | 247.7 | — | — | 100 | 30 | — | 100 | — | — | 72.7 | ||
Majdan, SF (14) | 100 | 1544.6 | 35.7 | 40.0 | — | 100 | 19 | 35.7 | 14.3 | — | 64.3 | 35.7 | |
Bialowieza, SF (6) | 100 | 387.5 | — | — | 100 | 18 | — | — | — | 100 | — | ||
Biebrza, FR (10) | 100 | 1802.5 | 40.0 | 437.5 | 30.0 | 150 | 100 | 28 | 20 | 70 | 30 | 90 | 80 |
Narew, SF (2) | 100 | 137.5 | — | — | 100 | 18 | — | 50 | — | — | 100 | ||
Monki, SF (8) | 100 | 637.5 | 50.0 | 183.8 | 12.5 | 400 | 100 | 22 | 37.5 | 62.5 | — | — | 37.5 |
Roztocze, FR (16) | 100 | 320.3 | 43.8 | 225 | 25.0 | 175 | 100 | 31 | 56.3 | — | 43.8 | 37.5 | 56.3 |
Roztocze, ST (13) | 100 | 1021.2 | 15.4 | 350 | — | 100 | 24 | 38.5 | — | 69.2 | 7.7 | 23.1 | |
Siriusz, ST (11) | 40.0 | 131.3 | — | — | 100 | 15 | 10 | — | — | — | |||
Types of horse management strategies: ST – stabled, SF – seml-free horses, FR – free-ranging horses
The dependence of gastrointestinal parasites infections in Polish primitive horses in regard to sex, age and management strategies: results of the Kruskal-Wallis test (H)
Sex | Age | Management Strategies | ||||
---|---|---|---|---|---|---|
H | p-value | H | p-value | H | p-value | |
EPG value data | ||||||
Strongylidae | statistically significant results are marked in bold | 2.65 | 0.266 | |||
1.84 | 0.175 | 4.77 | 0.091 | |||
0.83 | 0.36 | 1.62 | 0.44 | |||
Diagnostic deworming data | ||||||
Strongylidae | ||||||
2.15 | 0.142 | 4.00 | 0.14 | |||
1.32 | 0.250 | |||||
0.401 | 0.526 | 0.69 | 0.71 | 3.47 | 0.176 | |
2.91 | 0.088 | 1.81 | 0.41 | 3.65 | 0.161 | |
0.062 | 0.803 | 4.48 | 0.11 |
Significant differences in strongyle egg counts (EPG) were not observed between horses from the three age groups (Kruskal-Wallis test; p > 0.05). For
In regard to the management strategies, the significant differences in the EPG values were observed only for Strongylidae. For example, on the Popielno and Roztocze farms where horses were stabled and free-ranging, all FR horses had much higher levels of strongylid infection (aver. EPG = 1324.3 ± 973.8 SD) than ST horses (aver. EPG = 290.7 ± 225.1 SD). The level of strongylid infection in semi-free horses was intermediate. Significant relationships in infections with
Results of the diagnostic deworming examination revealed presence of
A similar analysis of the data on the number of parasites obtained by the diagnostic deworming technique compared to the sex, age groups and different management strategies of the horses also was carried out (Table 3). Similar to the EPG-value data, the Polish primitive horse females had a significantly higher infection with intestinal strongylids than males (Kruskal-Wallis test; p < 0.001). For others parasites (
The management strategies affected the level of parasite burdens only for strongylids,
Prevalence of gastrointestinal parasite infections in Polish primitive horses (n=124) from nine farms: results of diagnostic deworming
Farm/ Number of horses | Strongylidae | |||||
---|---|---|---|---|---|---|
Popielno, ST (22) | 100 | 4.5 | 45.5 | — | 63.6 | 45.5 |
Popielno, FR (11) | 100 | 63.6 | 100 | 18.2 | 72.7 | 90.9 |
Seven Isl., FR (11) | 100 | — | 100 | — | — | 72.7 |
Majdan, SF (14) | 100 | 35.7 | 14.3 | — | 64.3 | 35.7 |
Bialowieza, SF (6) | 100 | — | — | — | 100 | — |
Biebrza, FR (10) | 100 | 20 | 70 | 30 | 90 | 80 |
Narew, SF (2) | 100 | — | 50 | — | — | 100 |
Monki, SF (8) | 100 | 37.5 | 62.5 | — | — | 37.5 |
Roztocze, FR (16) | 100 | 56.3 | — | 43.8 | 37.5 | 56.3 |
Roztocze, ST (13) | 100 | 38.5 | — | 69.2 | 7.7 | 23.1 |
Siriusz, ST (11) | 100 | 10 | — | — | — | — |
Types of horse management strategies: ST – stabled, SF – semi-free, FR – free-ranging horses
Since intestinal strongylids were the most abundant group of parasites found in the Polish primitive horses in this study, the analysis of strongylid communities in horses of different sex, age groups and management strategies was performed. Totally, 31 species from 13 genera were identified: 6 species of large strongyles (subfamily Strongylinae) and 25 species of small strongyles (subfamily Cyathostominae). From 4 to 28 species were observed per horse (average 15.1 ± 5.1 SD).
Ten cyathostome species with the prevalence 80 – 100 % dominated the strongylid community of the Polish primitive horses; together they composed more than 93.5 % of the total number of strongylids collected. Large strongyles (Strongylinae) were found in 54.0 % of the horses examined: from 44.4 % for
Prevalence and proportion of 31 species in the strongylid community of the Polish primitive horses. Strongylinae: SVU –
ULT –
Analysis of the influence of sex and age of horses to the strongylid community structure revealed that statistically significant differences in prevalence of the separate strongylid species or their proportion in communities were not observed between females and males, or between the three age groups (Kruskal-Wallis test; p > 0.05).
Species diversity in strongylid communities of the Polish primitive horses significantly differed between horse farms (Table 2). The lowest number of species (15) was found on the farm “Syriusz”, where the horses are kept in stables, and the maximum numbers of strongylid species (30 and 31) were found on farms Seven Island and Roztocze in FR horses.
The types of management strategies of the horses had substantial influence on the strongylid community structure. The FR horses had significantly higher prevalence of large strongyles (Strongylinae) and their proportion in the community was higher compared to horses from others types of management strategies (Kruskal-Wallis test; p < 0.05). Division of the strongylid species into 10 prevalence classes also showed apparent differences in the strongylid community structures between horses from FR, SF and ST conditions (Fig. 3).
Distribution of the strongylid species between ten prevalence classes the Polish primitive horses kept under free-ranging (A), semi-free (B) and stable (C) horse-keeping conditions
This work represents the first extensive analysis of a dependence of infections of gastrointestinal parasites in Polish primitive horses in regard to their age, sex and management strategies. Our parasitological survey was carried out during a five year period at nine breeding farms located in four regions of north-eastern and central Poland. Previous studies of the gastrointestinal parasite community in Polish primitive horses and species composition of these parasites were carried out only at separate farms and involved smaller number of animals (Gawor, 2000; Romaniuk
The most abundant and pathogenic parasites of the Polish primitive horses documented in this study were strongylids (with a prevalence from 95.2 % with coprological examinations to 100 % in the diagnostic deworming studies) and parascarids (with a prevalence up to 30 %) (Table 2).
The gastrointestinal parasites we found in the Polish primitive horses are typical parasites of wild and indigenous breeds of horses in Poland and elsewhere in Europe (Romaniuk
In our studies, significant differences in gastrointestinal parasite communities associated with sex were observed only for the intestinal strongylids: females (mares and fillies) had significantly higher numbers of strongylids as compared to stallions and colts, using both the coprological examination data and the diagnostic deworming data (Table 3). Similar differences related to sex of horses were reported by other authors (Bucknell
Significant differences with infection of intestinal parasites associated with age were observed only for Strongylidae,
The more obvious differences in parasite infections in Polish primitive horses in our study were associated with the management strategies. The FR horses at all farms examined had higher levels of strongylid infection. In our opinion this finding was primarily associated with infrequent or absent anthelmintic treatments. On the contrary, more frequent deworming in ST horses resulted in a lower EPG values and poorer species biodiversity of the intestinal parasites. In the analysis of species composition of the strongylid communities we found that ST horses harbored the lowest number of species of these nematodes (15), while the highest species biodiversity (30 or 31) was documented in FR horses. Our findings correspond to the results of other authors who conducted similar studies in Poland (Kornas
The results of our survey of gastrointestinal parasite infections in Polish primitive horses depending on their age, sex and, especially, management strategies should be taken into account in elaboration of parasite control programs on farms and, in particular, during transportation of horses between farms to prevent spreading of parasites. Taking into account a high resilience of the Polish primitive horses to infection with different groups of gastrointestinal parasites (Romaniuk