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1.
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
2.
Paolini V Prevot F Dorchies P Hoste H 《Veterinary journal (London, England : 1997)》2005,170(2):260-263
The effects of tannins on adult populations of Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta in goats are characterised mainly by a decrease in egg excretion without any significant changes in worm number. In contrast, the impact of tannins on T. colubriformis or T. circumcincta third-stage larvae (L3) is associated with a significant reduction in worm establishment. The objective of the present study was to examine the effects of quebracho extract tannins on H. contortus L3. The consequences of consumption of sainfoin hay were also examined. Twenty-one na?ve kids were divided into three experimental groups. Group Q received quebracho extract and group S received sainfoin hay from days D3 to D5. Group C remained as an infected control group. All kids received 1500 L3 H. contortus on D0, D1 and D2. On D18, post-infection, the kids were slaughtered and the worm populations compared in the different groups. Compared to the control values, the worm counts decreased, respectively, by 33% and 38% in groups Q and S but the differences were not significant. No differences were found in pathophysiological measurements between the three groups. The results confirm differences in tannin effect according to nematode species but not parasitic stage. 相似文献
3.
Moreno FC Gordon IJ Knox MR Summer PM Skerrat LF Benvenutti MA Saumell CA 《Veterinary parasitology》2012,187(1-2):237-243
The study of the anthelmintic properties of plants rich in plant secondary metabolites can provide ecologically sound methods for the treatment of parasites on grazing animals. The purpose of the present study was to evaluate the anthelmintic effect of five tropical native Australian plant species rich in plant secondary metabolites on adult Haemonchus contortus and Trichostrongylus colubriformis in experimentally infected goats. Thirty young, nematode-free goats were infected with 2500 H. contortus and 5000 T. colubriformis infective larvae thrice weekly for a week (day 1-7 of the experiment). On day 27 after first infection, the goats were allocated into six groups of five animals per group. From day 28 to day 35, fresh leaves from Acacia salicina, Acacia nilotica, Eucalyptus corymbia, Casuarina cunninghamiana and Eucalyptus drepanophylla were included in the goats diet. Five groups were offered leaves from one of these plant species and one group, the untreated control, received only the basal diet formulated with 20% Medicago sativa and 80% Avena sativa. Following plant material administration, the goats were monitored daily until day 40 and then slaughtered on day 41. Total faecal worm egg output, total production of larvae recovered from faecal cultures, total post-mortem worm burdens and the per capita fecundity of female worms were estimated. The toxicity of the plant species for the goats was measured by histopathological analyses of liver and kidney samples. Results showed that goats feeding on the plant material rich in plant secondary metabolites had significantly lower egg output compared to the control goats (P<0.05). A similar response was found for larval production in both H. contortus and T. colubriformis supporting that egg output was affected in both species. Although the total worm burdens were not affected by the plant material (P>0.05), the per capita fecundity was significantly reduced by E. corymbia, A. nilotica and A. salicina (P<0.05). No signs of toxicity were detected in the liver or kidney samples. It is concluded that goats can benefit from the short-term ingestion of plant secondary metabolites, which reduce the total faecal egg output and thus decrease the potential for re-infection from the pasture. 相似文献
4.
Joshi BR Kommuru DS Terrill TH Mosjidis JA Burke JM Shakya KP Miller JE 《Veterinary parasitology》2011,178(1-2):192-197
Effect of sericea lespedeza [SL; Lespedeza cuneata (Dum-Cours.) G. Don.] leaf meal feeding was evaluated in two experiments in indoor reared goats with experimental infection of Haemonchus contortus larvae. In the first experiment, ten 8-10 month old male Spanish and Alpine cross kids pair matched for body weight and age were fed SL or bermudagrass [BG; Cynodon dactylon (L.) Pers.] hay one week before infection and were infected with 5000 H. contortus L(3). The animals were maintained on the same diet for the remaining period and were slaughtered 28 days post-infection (DPI) to determine the establishment of incoming infective larvae. Goats fed SL had lower establishment (P<0.05) of H. contortus larvae than that of the control goats fed BG hay. In the second experiment, twenty-five 8-10 months old male Alpine cross, Saanen, Nubian×Saanen and Spanish kids reared in confinement on BG were experimentally infected with 5000 H. contortus L(3). On 35 DPI, the animals were allocated to two groups after blocking by fecal egg count (FEC), and one group was fed SL leaf meal (n=13), and another control group remained on BG (n=12). Four goats/group were slaughtered successively on days 7, 14, and 28 days post SL feeding, except on day 7, when five SL fed goats were slaughtered. Fecal egg counts and blood packed cell volume (PCV) were measured at weekly intervals and worm count, female worm fecundity, worm length and mucosal eosinophils, mast cells and globule leucocytes were measured after slaughter. Goats fed SL had a lower FEC (P<0.05) one week after feeding, as compared to those fed on BG, and the values remained at low level thereafter. Similarly, PCV was also significantly affected by feeding (P<0.01), and feeding and time interaction (P<0.05). However, worm burden, female worm fecundity, parasite length, and mucosal inflammatory cell count were similar between the groups. Feeding SL reduced the establishment of infective larvae and FEC of H. contortus in experimental studies and this plant could be used for biological control of parasite infection under field conditions to limit the harmful effects of the parasites in goats. 相似文献
5.
This study was carried out to determine the effects of Acacia karoo and Acacia nilotica diets on Haemonchus contortus infections in goats. Twenty-four Boer goats of mixed sex (live weight 17-22 kg) were randomly assigned to four treatment groups, namely: A. nilotica (AN) group, A. karoo (AK) group, control infected with H. contortus (HC) group and the non-infected control (NHC) group. Animals in the AN, AK and HC groups were orally infected with a single dose of 3000 HC third stage larvae. The AN and AK groups had dried leaves of AN and AK, respectively, included in their basal diet at a rate of 40% dry matter (DM) while the HC and NHC groups had the basal diet throughout the experiment. All animals received a total feed allowance of 500 g DM per day and Katambora Rhodes grass hay ad libitum for roughage. Parameters measured included faecal egg counts and live weight. At the end of the experiment, three animals from each group were slaughtered and abomasal worm burdens were determined. A significant decrease in the faecal egg counts was recorded in animals in the AK group (P<0.05) relative to those in the AN and HC groups. The worm burdens were reduced by 34% in the AK group (P<0.05) and by 10% in the AN group (non-significant) relative to the infected control group. The study indicates that the difference in the effects of the two forages on HC infections may be related to type and concentration of tannins. 相似文献
6.
Hounzangbe-Adote Zinsou FE Hounpke V Moutairou K Hoste H 《Tropical animal health and production》2005,37(3):205-214
Infections of the gastrointestinal tract with parasitic nematodes, and particularly Haemonchus contortus, represent one of the main pathological constraints on the breeding of small ruminants in tropical countries. Owing to the constant development of anthelmintic resistance in worm populations, alternative control methods are being evaluated, including an assessment of the value of the traditional plants. The effect of the consumption of Fagara leaves on sheep infected with gastrointestinal nematodes was therefore measured both under controlled conditions and in a field survey. In sheep experimentally infected with 2500 third-stage larvae of H. contortus, a three-day administration of Fagara was associated with a decrease in egg excretion and a significant reduction in the fertility of female worms, without changes in the worm number. A reduction in egg output was also confirmed from the results obtained of a survey or naturally infected sheep performed in smallholder farms. This survey also indicated that the repeated consumption of small amounts of Fagara leaves was more effective than a single three-day administration. Results of both studies suggest that Fagara leaves might be an alternative option to chemotherapy to modulate the epidemiology of H. contortus in tropical countries. 相似文献
7.
Twelve parasite-naive sheep were used to study the possible direct anthelmintic effect of a condensed tannin extract (quebracho) on the population and fecundity of the intestinal nematode Trichostrongylus colubriformis. The sheep were infected with a single dose of 20,000 L3 of T colubriformis. Twenty-eight days later, six of them were drenched daily for a week with quebracho extract at 8 per cent by weight of their food intake. All lambs were then slaughtered, and their small intestines removed to estimate the worm burdens and the numbers of eggs in utero. Two days after the first drench with tannin extract the faecal egg counts of the treated sheep were approximately 50 per cent of those of the control sheep (P<0.01), but there was no further reduction with continued drenching. In the treated sheep the worm burdens and number of eggs per gram faeces per worm were reduced by 30 per cent compared with the controls (P<0.05), but the sex ratios, the number of eggs in utero and length of the worms were not affected by drenching with tannin. 相似文献
8.
Due to the high prevalence of anthelmintic resistance in goats, the need to explore novel approaches to control nematodes and to reduce the exclusive reliance on chemotherapy is strongly demanded in this host species. In sheep, several studies have shown that the consumption of tannin-rich legume forages was associated with positive effects on host resilience and resistance to parasite infection. In goats, studies on such interactions between tanniferous plants and nematode infections remain few. The objectives of the current study were to examine under natural conditions the effects of consumption of sainfoin hay by goats on the parasite populations and on host resilience. Eighteen adult cull goats naturally infected with Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis were used in the study. At the start of the assay, the goats were allocated into two groups, balanced according to weight and the levels of egg excretion. The two groups grazed separate pastures for 3 months with similar stocking rates. Goats from group S received each month indoors, for 7 days, sainfoin hay and control goats (group C) received hay of ryegrass. The diets in both groups were made isoenergetic and isoproteic and the refusals measured. Individual parasitological and pathophysiological measurements were performed fortnightly in order to compare host resistance and resilience. At the end of the study, five goats per group were necropsied. The distribution of sainfoin was associated with: (1) a higher consumption of hay; (2) significant, lower levels of nematode egg excretion which was associated with a decrease in worm fertility but no change in worm population; however, the number of intestinal worms was reduced by 50% in group S; (3) a better host resilience. In particular, after 2 months of grazing, two control goats died and half of the remaining animals needed to be treated whereas this was not the case in group S. These differences were related to significant changes in pepsinogen and phosphate values (PCV) but not in pepsinogen and phosphate concentrations. These results demonstrate that a repeated distribution of sainfoin hay to grazing goats might be beneficial in regard of pasture contamination and host resilience. They suggest that administration of sainfoin hay might represent a valuable alternative and adjunct to reduce nematode infections in dairy goat flock. 相似文献
9.
Developing effective biological control without the systematic use of anthelmintics is necessary to reduce the impact of gastrointestinal nematodes on small ruminants. Therefore, grazing management systems that use different host species to dilute nematodes in pasture appear to be promising for worm control. A trial was carried out to investigate the specificity of Haemonchus contortus for goats and cattle and to evaluate cross-infection between ruminant species. The effect of an experimental infection of 12 heifers by the free-living stages of H. contortus collected from goats (500 larvae per kg liveweight) was evaluated and compared to uninfected controls. After 28 and 35 days, egg excretion was measured. The experimental infection of heifers by H. contortus was not significant, with no egg excretion. These results, i.e., the lack of cross-infection of GIN between goats and cattle, suggest that integrated grazing using such animals could be employed for pasture dilution and decontamination. 相似文献
10.
11.
Weight gain costs due to infection were higher in sheep than goats, 28 and 17.5%, respectively, for Trichostrongylus colubriformis and 48.7 and 32.2%, respectively, for Haemonchus contortus. The extent of bodyweight cost attributed to anorexia in sheep infected with H. contortus was higher (13.5 g/day) than in sheep infected with T. colubriformis (2.3 g/day). On the other hand, bodyweight cost due to the other pathogenic effects in sheep infected with T. colubriformis were higher (35.6 g/day) compared to sheep infected with H. contortus (10.9 g/day). A strong relationship between faecal egg count and worm count (r=0.79, P=0.006) was shown only in sheep infected with T. colubriformis. About half of the infected sheep and goats had low or zero faecal egg counts throughout the study. In about 40% the egg count rose initially but became low by weeks 10-16, whereas in about 10% counts increased progressively throughout the period of observation and these animals also had the highest numbers of worms at slaughter. Packed cell volume was reduced in sheep and goats infected with H. contortus but serum protein and haemoglobin levels were unaffected. Sheep infected with T. colubriformis had a higher level of eosinophilia after 8 weeks (18.4%) than sheep infected with H. contortus (11.4%), whereas this pattern was reversed in goats and levels were also lower (4.1 and 8.9%, respectively). There was no apparent relationship between eosinophilia and resistance to infection with H. contortus or T. colubriformis. 相似文献
12.
13.
Direct anthelmintic effects of condensed tannins towards different gastrointestinal nematodes of sheep: in vitro and in vivo studies 总被引：1，自引：0，他引：1
In vitro and in vivo studies were conducted to determine possible direct anthelmintic effects of condensed tannins towards different ovine gastrointestinal nematodes. A larval development/viability assay was used to investigate the effect of a condensed tannin extract (Quebracho) towards larvae of Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus vitrinus. The development to infective larvae and their viability was assessed in all three species and LD 50 values were calculated. The presence of Quebracho extract in the cultures decreased the viability of L3 in all species; the LD 50 were not significantly different for the different species. Forty-eight sheep were allocated to one of eight groups and were infected with a single dose of either 4000 L3 H. contortus (groups 1 and 2) or 5000 L3 T. colubriformis and 5000 L3 Nematodirus battus simultaneously (groups 3-6) or 10,000 L3 of T. circumcincta (groups 7 and 8). From day 28 until day 31 of the experiment, sheep infected with the intestinal species were drenched with Quebracho extract at 4, 8 or 16% w/w of food intake, or remained as undrenched controls; sheep infected with the abomasal species were either drenched with Quebracho extract at 8% w/w of food intake or remained as undrenched controls. All sheep were slaughtered 4 days after the end of the drenching period. Sheep infected with the intestinal species and drenched with 16% w/w Quebracho had lower FEC compared to sheep drenched with 8% w/w (P<0.05), which in turn were lower than in sheep either drenched with 4% Quebracho or which remained undrenched (P<0.05). The lowest intestinal worm burden was recovered from sheep drenched with 8% w/w Quebracho extract (P<0.05). The administration of Quebracho extract at 8% of food intake for 3 days did not affect FEC or worm burdens in sheep infected with the abomasal species compared to controls. 相似文献
14.
Brunet S de Montellano CM Torres-Acosta JF Sandoval-Castro CA Aguilar-Caballero AJ Capetillo-Leal C Hoste H 《Veterinary parasitology》2008,157(1-2):81-88
The consumption of tannin-rich (TR) forages has been associated with negative effects against gastrointestinal nematodes and with an improved host resilience. It has been hypothesized that tannins affect the capacity of infective larvae to establish in the mucosae of the host. In this study, we aimed at testing this hypothesis using Lysiloma latisiliquum, a tropical TR tree. The objectives were: (i) to evaluate the effect of the consumption of L. latisiliquum on the establishment of nematode third-stage larvae (L3) in goats; (ii) to define the role of tannins in these effects in vivo by using an inhibitor (polyethylene glycol, PEG); and (iii) to examine a possible indirect effect of tannins on the inflammatory response in the digestive mucosa. Eighteen Criollo goats composed three experimental groups. The control group received fresh leaves of Brosimum alicastrum, a plant with a low level of tannins. Two groups received L. latisiliquum leaves either with (L.L.+PEG) or without (L.L.) daily addition of 25g PEG. After a 7-day adaptation period, each goat was infected with both Haemonchus contortus and Trichostrongylus colubriformis (3000 L3 per species). The goats were slaughtered 5 days after infection and worm counts and histological analyses were performed. No difference in the voluntary feed intake of foliage was observed between the 3 groups. The consumption of L. latisiliquum significantly reduced the larval establishment of both nematode species compared to the control (P<0.01). For both worm species, the effects were totally alleviated with PEG (L.L.+PEG group), suggesting a major role of tannins in the observed effects. Only minor differences in the mucosal cellular response were observed between the 3 groups. These results confirm that the consumption of TR plants reduces the establishment of nematode larvae in the host and that a direct effect is principally involved. 相似文献
15.
Iqbal Z Sarwar M Jabbar A Ahmed S Nisa M Sajid MS Khan MN Mufti KA Yaseen M 《Veterinary parasitology》2007,144(1-2):125-131
Anthelmintic activity of condensed tannins (CT) was evaluated both in vitro and in vivo. In vitro tests included egg hatch test and paralysis/mortality assay on adult Haemonchus contortus. In vivo anthelmintic effect was determined by faecal egg count reduction test in lambs. To this end, 18 lambs were divided into three groups (low tannin, high tannin and control). The lambs of low and high tannin groups were fed diets containing 2 and 3% CT while the control group was fed on diets without CT. In vitro trials showed a dose-dependent inhibition of nematode egg hatching; whereas, there was no effect of CT on adult H. contortus. In vivo trials indicated reduction in faecal egg counts in lambs fed diets containing CT. Feed intake and nutrient digestibility of CT-fed sheep was lower and nitrogen balance was higher as compared to control. Maximum weight gain was observed in animals fed diets containing 3% CT. The direct anthelmintic effect of CT, therefore, was evidenced by inhibited egg hatching; whereas, faecal egg counts reduction in sheep was through improved nutrient utilization. 相似文献
16.
Bambou JC de la Chevrotière C Varo H Arquet R Kooyman FN Mandonnet N 《Veterinary parasitology》2008,158(4):311-318
The objective of this study was to evaluate the relationship of parasite-specific serum antibodies with the resistance status of Creole kids. The average breeding values on egg output predicted in a context of natural infection at 11 months of age were distant of 1.07 genetic standard deviation between resistant and susceptible animals. After drenching the animals were maintained worm-free during 1 month until experimental infection with 10,000 Haemonchus contortus infective larvae (L3). Enzyme-linked immunosorbent assay was carried out in serum samples to determine the level of IgG, IgA and IgE anti-H. contortus L3 crude extracts and adult excretion/secretion products (ESP). Parasitological and blood immunological parameters were measured on the 2 extreme groups. Despite the absence of any typical signs of haemonchosis, susceptible kids had more than 11 times higher faecal egg counts (FEC) at 35 days post-infection (d.p.i.) than resistant kids had. Levels of immunoglobulin against H. contortus L3 and ESP increased significantly after infection in both groups. However, no difference in the host immune response mediated by immunoglobulin against H. contortus was evidenced between groups. This finding suggests that, in goats previously infected by H. contortus, a degree of protection occurred and the phenotypic and genetic segregation in resistant and susceptible animals were not related to the humoral immune response. The correlation coefficients between FEC and IgE anti-ESP (r=0.593; P<0.05 was significant in both resistant and susceptible animals. Such correlation suggesting a hypersensitivity reaction dependent on worm prolificacy has never been described. This result needs further studies to understand the mechanisms underlying this observation. 相似文献
17.
Worm egg counts of yearling Angora or Merino wethers grazing in mixed flocks at either 4/ha or 8/ha were observed over a 5 month period. Based on faecal egg counts infection levels in the sheep increased for the first 3 months and then decreased as the animals developed resistance. Egg counts in the goats did not decrease during the experiment. Post mortem worm counts indicated that there was a significant host species--stocking rate interaction on worm burdens of Haemonchus contortus adults and Ostertagia circumcincta adults and larvae. Goats had more H. contortus and O. circumcincta adults than sheep at the 8/ha stocking rate. At 4/ha goats had fewer O. circumcincta fourth stage larvae than sheep. There was no stocking rate effect on the numbers of Trichostrongylus axei or T. colubriformis. Sheep had more T. axei and fewer T. colubriformis than goats. 相似文献
18.
The effectiveness of selective anthelmintic treatments and use of nematophagous fungi Duddingtonia flagrans in reducing levels of gastrointestinal nematodes in goats was investigated at Onderstepoort, South Africa. Nineteen (19) naturally infected indigenous male goats, aged 10 months, were separated into four groups and grazed in separate previously ungrazed paddocks for two worm seasons (February 2002-March 2003). Two groups of goats were fed D. flagrans chlamydospores daily and two groups did not receive fungi. The FAMACHA system was used to determine which goats required anthelmintic treatments. Twice as many goats in the no-fungi fed group required treatments as compared with the fungi fed group. Mean FAMACHA scores in the no-fungi fed group were higher during most of the sampling occasions compared to the group fed fungi, but the difference was not significant. The group-mean faecal egg counts and PCV% were comparable between the two treatment groups throughout the study. Haemonchus was the predominant parasite genus in composite group faecal cultures. Group-mean body weights and body condition scores were higher for the no-fungi fed group from May 2002 up to the end of the study, though statistical differences were not significant. Mean worm burdens indicated that the most abundant species infecting animals were Haemonchus contortus and Trichostrongylus spp. and were higher in the fungi fed group. More animals required individual anthelmintic treatments in the no-fungi fed group. The requirement for extra treatments in the no-fungi fed group must, however, be considered against the financial cost of the fungi, the requirement of daily feeding of the fungi, the lower performance and higher worm burdens in the fungi fed group. 相似文献
19.
N C Sangster H V Whitlock J D Kelly M Gunawan C A Hall 《Research in veterinary science》1979,26(1):85-89
Sheep infected with benzimidazole resistant strains of Haemonchus contortus and Trichostrongylus colubriformis were used to compare the anthelmintic efficacy of fenbendazole given as a single dose or administered in a divided dose regime over five days. Statistical analysis showed no significant difference between the two methods of administration for H contortus. On the other hand, divided dose fenbendazole was significantly less effective than single doses against adult T colubriformis at dose rates of 5 and 7.5 mg/kg. In the case of H contortus a highly significant correlation coefficient between post treatment egg counts and worm counts (r = 0.789) was obtained. This suggests that reduction in faecal egg output following drug treatment would provide a useful field indication of anthelmintic performance of fenbendazole (and possibly related compounds) against benzimidazole resistant strains of this parasite. 相似文献
20.
OBJECTIVE; To show that low bodyweight is a predisposing cause of high Trichostrongylus colubriformis and Haemonchus contortus burdens and egg counts in Merino lambs. DESIGN: A comparison was made, among lambs of different bodyweights, on the effect on immunity of a primary or secondary viable infection with T colubriformis or H contortus larvae. PROCEDURE: Sixty-one Merino lambs, 1 or 6 months of age, were penned indoors and given primary, or both primary and secondary, infection of T colubriformis or H contortus. Faecal egg counts, worm counts and parasite-specific immunoglobulin concentrations were examined for their relationships with bodyweight. RESULTS: Bodyweight at the start of a primary infection was correlated with worm burden, worm fecundity and jejunal IgA antibody concentration. Merino lambs weighing less than 23 kg at the time of first exposure to T colubriformis or H contortus had impaired ability to develop protective mucosal immunity and to resist homologous challenge. CONCLUSION: If the goal is to ensure that lambs develop immunity before weaning, then every endeavour should be made to achieve the combination of critical bodyweight and exposure to moderate levels of nematode infection as soon as possible. 相似文献