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1.
The frequency, distribution and repeatability of measurements related to infection with gastrointestinal nematodes have been estimated in dairy goats. Monthly faecal and blood samples were taken over two grazing seasons from a flock of 120 naturally infected goats. The frequency distribution of egg excretion was positively skewed at each sampling date, suggesting an aggregative distribution of parasites. Overdispersed distributions were also apparent for pepsinogen and inorganic phosphate values. Repeatabilities for each parameter were estimated within each year. The values ranged between 0.23 to 0.43 and were relatively similar during the 2 years, with the highest coefficients recorded for pepsinogen. For each parameter, moderate to high repeatabilities were also estimated between the 2 years. Overall, the data suggest that, in dairy goats, the distribution of worms is overdispersed with a few individuals repeatedly harbouring large worm populations. These results have practical implications for genetic selection for resistance to worm infection and for selective administration of anthelmintics. 相似文献
2.
Tabouret G Lacroux C Andreoletti O Bergeaud JP Hailu-Tolosa Y Hoste H Prevot F Grisez C Dorchies P Jacquiet P 《Veterinary research》2003,34(2):231-241
Cellular and humoral local responses were investigated following repetitive artificial Oestrus ovis infections in lambs. The presence of larvae induced a huge local recruitment of either leucocytes (T and B lymphocytes, macrophages) or granulocytes (eosinophils, mast cells and globule leucocytes). This cellular response was more pronounced in the ethmoid and sinus (development sites of second and third instar larvae) than in the septum or turbinates where first instar larvae migrate. Infected lambs produced Oestrus ovis specific IgG and IgA antibodies in their mucus. This local humoral response was mainly directed against larval salivary gland antigens and not against larval digestive tract antigens. Compared to the control animals, the sinusal mucosa of infected animals was extremely thickened and the epithelium exhibited hyperplasia, metaplasia and eosinophilic exocytosis. The possible roles of these local immune responses in the regulation of O. ovis larvae populations in sheep are discussed. 相似文献
3.
Forty-two horses from Normandy (France) were examined post-mortem for small strongyle infections from October to March. In the positive horses, total worm numbers ranged from 234 to 90,247 (mean 11,297). Encysted larvae represented the major part of the total cyathostome burdens with a high percentage (83%) being early third stage larvae. They were mostly recovered from the caecum (48%) and ventral colon (40%) and were less present in the dorsal colon (12%). Adult cyathostomes were mainly located in the ventral colon (64%) and less frequently in the dorsal colon (27%) and caecum (9%). Twenty species of Cyathostominae were identified. The 10 most prevalent species (in sequence of prevalence) were Cyathostomum coronatum, Cylicocyclus nassatus, Cylicocyclus insigne, Cyathostomum catinatum, Cylicostephanus goldi, Poteriostomum imparidentatum, Cyathostomum labiatum, Cylicocyclus ultrajectinus, Cylicostephanus calicatus and Cylicostephanus minutus which comprised 84% of the total adult population. Twelve species showed a site preference in the ventral colon, five in the dorsal colon and only one in the caecum while two species were collected in nearly equal numbers from the ventral and dorsal colon. The number of species per horse ranged from 1 to 12 with a median of 5. Infections with singletons occurred in 12.5% of the positive horses while multiple infections were encountered in 87.5%. A positive correlation was found between the intensity of cyathostome infection and its diversity, measured either by the number of occurring species or Shanon indexes. 相似文献
4.
Hounzangbe-Adote MS Paolini V Fouraste I Moutairou K Hoste H 《Research in veterinary science》2005,78(2):155-160
Alcoholic extracts of four tropical plants (Zanthoxylum zanthoxyloides, Newbouldia laevis, Morinda lucida and Carica papaya) were screened in vitro for potential anti-parasitic effects against eggs, infective larvae and adult Haemonchus contortus. Significant effects were obtained with all four plants but differences were observed depending on the parasitic stage. The effects of the four plant extracts were similar on egg hatching and were dose dependent. In contrast, no dose-response relationship was found for infective larvae and adult worms, although more potent effects were usually observed with the highest concentrations. Using a larval inhibition migration test, extracts of fagara (Z. zanthoxyloides) were found to be less active against Haemonchus infective larvae than were the other plants. N. laevis was found to be highly and rapidly effective against adult worms. Overall, these in vitro results suggest that these four plants, traditionally used by small farmers in Western Africa, do possess anti-parasitic properties. These effects remain to be confirmed through in vivo studies. 相似文献
5.
Yacob HT Duranton-Grisez C Prevot F Bergeaud JP Bleuart C Jacquiet P Dorchies P Hoste H 《Veterinary parasitology》2002,104(4):307-317
Concurrent infections of sheep with Oestrus ovis and trichostrongyles of the digestive tract are common in the field. In order to examine the possible occurrence of interactions between these two parasites and the consequences on parasite biology and the associated pathophysiological changes, an experimental study was conducted on four groups of na?ve sheep. Group O was infected repeatedly with O. ovis larvae from D0 to D42 of experiment; group T received a single infection of Trichostrongylus colubriformis on D49; sheep from group OT received both infections, and animals from group C remained uninfected as controls. Parasitological and pathophysiological parameters were measured regularly. At necropsy (D94), the mucosal cellular responses in the nasal cavities and digestive tract from all animals were analysed from histological sections. Infection of the digestive tract with nematodes did not modify the biology of Oestrus populations. In contrast, the presence of O. ovis was related to significant reductions in nematode egg excretion, worm fecundity and worm burdens. These changes were associated with significant modifications in tissular populations of mast cells, globule leucocytes and eosinophils in the respiratory and digestive tracts. These results indicate that parasitic infection in one particular anatomical site induces "at distance" inflammatory reactions of the whole mucosal system. The relationships between the cellular response and the changes in worm biology are discussed. 相似文献
6.
Haemonchus infection was monitored for 2 years (six kidding periods) in a Creole goat flock grazing under oceanic-tropical climate. Two hundred and thirty individual does were involved from late pregnancy to weaning. Anaemia diagnoses using Famacha method and packed cell volume (PCV) were compared. The best agreement (Kappa=0.33) was found if anaemia was declared when PCV values fell to 16 or below and Famacha score was 4 or 5. Drenching policy according to Famacha method was compared to systematic drenching policy. Using the Famacha method allowed a dramatic decrease in anthelmintic use during the periparturient period (0.57 individual dose instead of three doses for the control). The proportion of the nematode population on the pasture not derived from previously-treated goats (in refugia) was estimated to about 79% (65-90%) of the pasture contamination derived from the Famacha group. On the average, goats which needed to be drenched produced less than the control or undrenched goats (kid average daily gain was decreased by about 15%). The repeatability of the need for drenching individual does was estimated to 0.41. The older goats or the goats in poorer body condition at kidding needed more drenching than the younger animals and the animals in good body condition. Consequently the Famacha method may be used as an additional tool for the culling management. 相似文献
7.
The current control of parasitic nematodes in small ruminants relies on the use of chemical anthelmintics, but the development of resistance requires research in alternatives. Bioactive plants represent one of those solutions. Previous results suggest that plants rich in condensed tannins (CTs) might have direct anthelmintic effects. However, the relationships between the biochemistry of active compounds and the mechanisms of action remain to be elucidated. Therefore, this study examined in vitro the effects of different CT monomers on the exsheathment of infective larvae for two nematode species. Monomers of prodelphinidins were more potent inhibitors of exsheathment than those of procyanidins. More severe inhibition was also found with galloyl derivatives. These results suggest that the number of free hydroxy groups of CT monomers is a key factor in interactions with parasite larvae. Comparison of effects between the two nematodes suggests different susceptibility to monomers depending on species, which might be related to the protein composition of sheaths. 相似文献
8.
Jacquiet P Tran Thi Ngoc T Nouvel X Prevot F Grisez C Yacob HT Bergeaud JP Hoste H Dorchies P Tabouret G 《Veterinary immunology and immunopathology》2005,105(1-2):95-103
Larvae of Oestrus ovis (Insecta: Diptera: Oestridae) are common parasites of nasal and sinus cavities of sheep and goats. During larval development, a specific immune reaction is initiated by the host with a humoral local and systemic response and the recruitment of eosinophils and mast cells in the upper airways mucosae. Nevertheless, the roles of these responses in the regulation of O. ovis larvae populations in sheep are not yet known. The aim of this study was to compare the establishment and the development of larvae as well as some inflammatory or immune parameters between different groups of half-sibling sheep: (i) a primed group experimentally infected twice before a challenge infection, (ii and iii) two groups infected once only and previously treated with a long-lasting cortico?d before the challenge (one group) or not (the other group). A fourth group of non-infected animals was added in the experimental design. The larval establishment rate was 23% in the cortico?d treated group compared to about 10% in the two other infected groups. Moreover, the larval development appeared more rapid in the cortico?d treated group than in the two other infected groups suggesting that the inflammatory response is involved in the regulation of O. ovis populations. By contrast, no differences in the establishment rates were shown in the primed group compared to the na?ve group (without cortico?d treatment) despite evidence of higher eosinophilia, serum specific IgG, and immediate hypersensibility to excretory-secretory products of larvae. The specific lymphocyte proliferation was reduced in the primed group compared to the na?ve one suggesting that an immuno-suppression occurs following repetitive O. ovis infections. 相似文献
9.
Torres-Acosta JF Aguilar-Caballero AJ Le Bigot C Hoste H Canul-Ku HL Santos-Ricalde R Gutiérrez-Segura I 《Veterinary parasitology》2005,134(3-4):241-248
The objective was to examine the coincidence in the prevalence of benzimidazole (Bz) resistance in smallholder goat herds, as determined by three average-based and two individually-based faecal egg count reduction (FECR) tests. Nineteen smallholder goat herds with more than 30 animals were selected from 84 herds in Yucatan. Animals shedding 150 eggs/g of faeces (EPG) on day zero were randomly divided into two groups. The control group did not receive treatment and the treated group received fenbendazole (10mg/kg body weight per os). Feed was withdrawn for 16 h before treatment. Ten days after treatment, both groups were sampled to determine their FEC. Faecal cultures and identification of infective larvae were performed for estimating the proportions of genera of gastrointestinal nematodes (GIN) present. Presence of resistant GIN was determined with three different average-based FECR (FECR(1), FECR(2) and FECR(3)) and two individually-based FECR (iFECR(1) and iFECR(2)). The prevalence of herds with Bz resistant nematodes (and 95% confidence interval (95% CI)) was calculated using each formula. Coincidence among formulae was estimated with Kappa values. The prevalence (+/- 95% CI) of Bz resistance calculated with FECR(1) (57.89 +/- 22.20) had a high coincidence with iFECR(1) and iFECR(2) (Kappa values of 0.86 and 0.79, respectively). The prevalence with FECR(2) (31.58 +/- 20.90) and FECR(3) (21.05 +/- 18.33) had a low coincidence with FECR(1) (Kappa < 0.50). Trichostrongylids found on Bz resistant farms were mainly Haemonchus spp., however, some Trichostrongylus spp. and Oesophagostomum spp. were found too. The high coincidence between the standard average-based FECR(1) and the individually based formulae is encouraging and may suggest that either formula could be applied to smallholder farmers. Further laboratory studies are needed to confirm the resistance status in the herds. 相似文献
10.
The use of tanniferous plants or tannins represents one alternative approach to the control of gastrointestinal parasites in ruminants but most data have been obtained in sheep. The current study was therefore performed in goats with two objectives: firstly, to investigate the effects of condensed tannins (CT) on adult populations of Trichostrongylus colubriformis and Teladorsagia circumcincta; secondly, to examine their effects on the establishment of infective larvae of these two species. In experiment 1, two groups of kids were infected with 6 000 L3 of T. colubriformis and 6 000 L3 of T. circumcincta. After 7 weeks, quebracho extracts were administered per os for 8 days to one group. A comparable group which did not receive tannins was included as the control. The kids were slaughtered on week 11. Parasitological and pathophysiological parameters were measured weekly. Worm counts were assessed and mast cells, globule leukocytes and eosinophils were counted in the abomasal and intestinal mucosae. Tannin administration was associated with a decrease in egg excretion, and a decrease in female fecundity, but with no changes in worm numbers. These changes were associated with an increased number of intestinal mast cells. In experiment 2, 24 goats were used according to a 2 x 2 factorial design, depending on infection and tannin administration. Two groups were either infected with 6 000 L3 of T. colubriformis or T. circumcincta. Within each group, the goats were either drenched or undrenched with tannin extracts. Pathophysiological parameters were measured weekly. Twelve days after the cessation of tannin administration, the goats were slaughtered. Worm counts and female worm fecundity were determined. Tannin consumption was associated with a significant reduction (P < 0.01) of Trichostrongylus populations and a close to significant reduction for Teladorsagia. No effect on fecundity was observed. Our results (1) confirm the consequences of condensed tannins on nematodes in goats as in sheep and (2) indicate divergent effects depending on the parasitic stage exposed to the condensed tannins. 相似文献