Evaluation of three Pakistani sheep breeds for their natural resistance to artificial infection of Haemonchus contortus

Monospore cultures of black spot (Diplocarpon rosae Wolf) were established from isolates collected on outdoor grown roses at different locations in Belgium. These monospore cultures were tested on rose cultivars and species with different levels of natural resistance to examine the possible existence of different pathotypes. For this purpose a screening protocol including scoring after artificial infection was developed on in vitro plantlets. Differences between the examined isolates proved that there exist different pathotypes of Diplocarpon rosae in Belgium.

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Innate Immune Responses Associated with Resistance against Haemonchus contortus in Morada Nova Sheep

Journal of Immunology Research ◽

10.1155/2019/3562672 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

João Henrique Barbosa Toscano ◽

Cintia Hiromi Okino ◽

Isabella Barbosa dos Santos ◽

Luciana Aparecida Giraldelo ◽

Marei Borsch von Haehling ◽

...

Keyword(s):

Immune Response ◽

Haemonchus Contortus ◽

Innate Immune ◽

Blood Levels ◽

Artificial Infection ◽

Proinflammatory Response ◽

Tissue Samples ◽

Blood Samples ◽

The Third ◽

Pyloric Mucosa

The immune response against Haemonchus contortus infections is primarily associated with the Th2 profile. However, the exact mechanisms associated with increased sheep resistance against this parasite remains poorly elucidated. The present study is aimed at evaluating mediators from the innate immune response in lambs of the Morada Nova Brazilian breed with contrasting H. contortus resistance phenotypes. Briefly, 287 lambs were characterized through fecal egg counts (FEC) and packed cell volume (PCV) after two independent experimental parasitic challenges with 4,000 H. contortus L3. 20 extreme resistance phenotypes (10 most resistant and 10 most susceptible) were selected, subjected to a third artificial infection with 4,000 L3, and euthanized 7 days later. Tissue samples were collected from abomasal fundic and pyloric mucosa and abomasal lymph nodes. Blood samples were collected at days 0 and 7 of the third parasitic challenge. RNA was extracted from tissue and blood samples for relative quantification of innate immune-related genes by RT-qPCR. For the abomasal fundic mucosa, increased TNFα and IL1β expression levels (P<0.05) were found in the susceptible animals, while resistant animals had IL33 superiorly expressed (P<0.05). Higher levels (P<0.05) of TLR2 and CFI were found in the abomasal pyloric mucosa of resistant animals. TNFα was at higher levels (P<0.05) in the blood of susceptible lambs, at day 0 of the third artificial infection. The exacerbated proinflammatory response observed in susceptible animals, at both local and systemic levels, may be a consequence of high H. contortus parasitism. This hypothesis is corroborated by the higher blood levels of TNFα before the onset of infection, which probably remained elevated from the previous parasitic challenges. On the other hand, resistant lambs had an enhanced response mediated by TLR recognition and complement activation. Nevertheless, this is the first study to directly associate sheep parasitic resistance with IL33, an innate trigger of the Th2-polarized response.

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Comparative experimental Haemonchus contortus infection of two sheep breeds native to the Canary Islands

Veterinary Parasitology ◽

10.1016/j.vetpar.2008.02.019 ◽

2008 ◽

Vol 153 (3-4) ◽

pp. 374-378 ◽

Cited By ~ 29

Author(s):

Jorge F. González ◽

Álvaro Hernández ◽

José M. Molina ◽

Antonio Fernández ◽

Herman W. Raadsma ◽

...

Keyword(s):

Canary Islands ◽

Haemonchus Contortus ◽

Sheep Breeds

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Genetic Selection for Resistance to Gastrointestinal Parasitism in Meat Goats and Hair Sheep through a Performance Test with Artificial Infection of Haemonchus contortus

Animals ◽

10.3390/ani11071902 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1902

Author(s):

Yoko Tsukahara ◽

Terry A. Gipson ◽

Steven P. Hart ◽

Lionel Dawson ◽

Zaisen Wang ◽

...

Keyword(s):

Haemonchus Contortus ◽

Performance Test ◽

Genetic Selection ◽

Total Serum ◽

Parasite Resistance ◽

Artificial Infection ◽

Hair Sheep ◽

Meat Goats ◽

Selection For ◽

Selection Of

Internal parasitism has been the leading cause of morbidity and mortality in small ruminants in many areas such as the southcentral USA. Among the different approaches and management practices to cope with internal parasitism, genetic selection for internal parasite resistance is recognized as one with considerable potential long-term impact. A central performance test with artificial infection of Haemonchus contortus for selection of growing meat goats and hair sheep for breeding to increase resistance to internal parasitism and on-farm selection of females was conducted for 3 years. The results varied considerably among breeds of goats and flocks of sheep. Spanish goats and St. Croix sheep maintained relatively low fecal egg count (FEC) each year, whereas for goats categorized as being of high resistance and Dorper sheep FEC decreased with advancing year. Packed call volume (PCV) and total serum immunoglobulin (Ig) levels were not strongly related to FEC. Genetic parameters varied between the two species, which might be related to previous selection pressure exerted for parasite resistance. Heritability of FEC was higher in goats than sheep. The genetic correlation between FEC and IgM and IgG was negative for both species, which suggests possible genetic association. Genetic and phenotypic correlations between ADG and FEC were nonsignificant for both species. In conclusion, different relationships of FEC and PCV between species require careful attention during selection and the lack of relationship between ADG and FEC suggests that selection of growing male meat goats and hair sheep for resistance to internal parasitism will not adversely affect growth performance.

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1705 The response to artificial infection with Haemonchus contortus and growth performance of sheep and goat progeny of selected parents in a central performance test

Journal of Animal Science ◽

10.2527/jam2016-1705 ◽

2016 ◽

Vol 94 (suppl_5) ◽

pp. 831-831

Author(s):

Y. Tsukahara ◽

T. A. Gipson ◽

S. P. Hart ◽

L. J. Dawson ◽

Z. Wang ◽

...

Keyword(s):

Growth Performance ◽

Haemonchus Contortus ◽

Performance Test ◽

Artificial Infection

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Artificial Haemonchus contortus infection as a strategy to induce protective immune response to natural infection in Pelibuey lambs

Journal of Helminthology ◽

10.1017/s0022149x20000656 ◽

2020 ◽

Vol 94 ◽

Author(s):

A. Cruz-Tamayo ◽

R. González-Garduño ◽

G. Torres-Hernández ◽

C. Becerril-Pérez ◽

O. Hernández-Mendo ◽

...

Keyword(s):

Immune Response ◽

Haemonchus Contortus ◽

Natural Infection ◽

Phase 1 ◽

Acquired Resistance ◽

Gastrointestinal Nematodes ◽

Phase 2 ◽

Artificial Infection ◽

Faecal Egg Count ◽

Two Phases

Abstract The objective of this study was to evaluate the reduction in nematode faecal egg count (FEC) in Pelibuey lambs segregated as resistant (RES), susceptible (SUS) and intermediate (INT) to gastrointestinal nematodes. Twenty-nine weaned Pelibuey lambs, aged five months old, free of nematode infection, were used. Nine lambs were RES, six were SUS and 14 were INT lambs. The study consisted of two phases: in Phase 1 the lambs were infected experimentally with Haemonchus contortus. In Phase 2, the lambs were naturally infected by grazing. Faecal and blood samples were taken every week. The packed cell volume and total protein were quantified. The FEC value (FECmax) per lamb was recorded together with a natural reduction in FEC in the two phases. The data were analysed with a model of measures repeated over time. During Phase 1, the RES lambs showed the lowest FEC (1061 ± 1053) compared to the other groups (INT: 2385 ± 1794 eggs per gram of faeces (EPG); and SUS: 3958 ± 3037 EPG). However, in Phase 2 no significant differences (p > 0.05) were observed between the groups of lambs (RES: 275 ± 498 EPG; SUS: 504 ± 1036 EPG; and INT: 603 ± 1061 EPG). At the end of Phase 1, the FEC of RES lambs was naturally reduced by 75.5% in respect to FECmax (p < 0.05), and at the end of Phase 2 the reduction in FEC was 90% in respect to FECmax (p > 0.05); the same behaviour was observed in RES and SUS lambs. It is concluded that the artificial infection in the lambs induced a more rapid immune response in RES than SUS lambs, and all lambs developed high acquired resistance by continuous infection.

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