Vertical migration of Haemonchus contortus infective larvae on Cynodon dactylon and Paspalum notatum pastures in response to climatic conditions

2010 ◽  
Vol 170 (1-2) ◽  
pp. 78-87 ◽  
Author(s):  
Bimal S. Amaradasa ◽  
Robert A. Lane ◽  
Ananda Manage
Author(s):  
Jennifer Mayara Gasparina ◽  
Renata Grasieli Baby ◽  
Lidiane Fonseca ◽  
Patrizia Ana Bricarello ◽  
Raquel Abdallah da Rocha

Abstract The resistance of gastrointestinal nematodes (GIN) of sheep to anthelmintic treatment has motivated researchers to seek alternatives to reduce the use of these drugs in sheep farming and decontaminate pastureland based on knowledge about the survival dynamics of larvae. The aim of this work was to evaluate the migration of the infective larvae (L3) of Haemonchus contortus at different times of the day, strata, and sward heights, with and without shade after the deposition of contaminated sheep feces. The grass species used here was Cynodon dactylon cv. Tifton 85 in four treatments: low sward height shade; low sward height sunshine; high sward height shade; and high sward height sunshine. The number of L3 recovered from the pasture at different times of the day did not differ. The highest number of L3 recovered was in shade. The number of L3 at different times and strata occurred uniformly, confirming that L3 remain in the same place after migrating from dung at the hottest times of the day. Infective larvae of H. contortus were able to migrate across all the strata regardless of the time of day in the summer season in humid subtropical climate.


2008 ◽  
Vol 60 (4) ◽  
pp. 864-872 ◽  
Author(s):  
R.D. Carneiro ◽  
A.F.T. Amarante

To evaluate both the development and survival of free-living stages of Haemonchus contortus obtained from feces of infected ovine in the four seasons of the year, eggs of this nematode were deposited on three grass species commonly used as sheep pasture in Brazil (Brachiaria decumbens cv. Australian, Cynodon dactylon cv. Coast-cross, and Panicum maximum cv. Aruana). The grasses were cut 5 or 30cm height before depositing the feces. Samples of grasses and feces were collected in six sub-plots from each plot one, two, four, eight, 12, and 16 weeks after contamination to determine the recovery of infective H. contortus larvae. Most infective larvae were recovered from feces or grass samples deposited on 30cm height herbage. High temperature and precipitation levels during the rainy season reduced the infective larvae recovery period from the environment. The best weather conditions for larvae development and survival, in both feces and grasses, were lower temperatures, around 17ºC, in association with low precipitation levels. In general, more larvae were recovered when fecal samples were deposited on Aruana grass.


Parasitology ◽  
1950 ◽  
Vol 40 (1-2) ◽  
pp. 127-143 ◽  
Author(s):  
Gwendolen Rees

1. The cycle of vertical migration of the infective larvae of Haemonchus contortus on experimental plots of Lolium perenne S 24, kept out of doors, has been related to meteorological and micrometeorological factors.2. The three main factors concerned with vertical migration are temperature, humidity and light intensity.3. In the majority of cases the greatest number of larvae are on the grass blades in the early morning and in the evening, less being recovered at night and during the middle of the day. The time of the morning maximum becomes progressively earlier passing from winter to summer, and the time of the evening maximum progressively later. The reverse is true in the second half of the year.4. Low and high temperatures accompanied by low humidity inhibit vertical migration on the grass.5. High humidity (continuous precipitation) does not prevent migration, the two daily maxima are apparent, but the numbers climbing are less than in the absence of rain.


2008 ◽  
Vol 41 (5) ◽  
pp. 775-782 ◽  
Author(s):  
Aruaque L. F. Oliveira ◽  
Ciniro Costa ◽  
Roberto A. Rodella ◽  
Bruna F. Silva ◽  
Alessandro F. T. Amarante

1963 ◽  
Vol 37 (4) ◽  
pp. 251-254 ◽  
Author(s):  
M. G. Christie ◽  
J. E. Patterson

A pellet of sheep faeces containing eggs of Haemonchus contortus forms an adequate environment for the development of those eggs to third stage infective larvae, provided that it is kept moist. Observation shows a concentration of developing larvae on the external mucous coat of the pellet. These data suggest that optimum conditions for development would occur when pellets are separated one from another and standing on a water repellent surface, thus presenting the maximum free surface area and minimum opportunity for aggregation and hence of over crowding. The best method of recovering the infective larvae would be one that obtained larvae free from contamination without requiring them to expend energy in separating themselves from the contamination.


1950 ◽  
Vol 1 (3) ◽  
pp. 285 ◽  
Author(s):  
DF Stewart

All antigen was developed to detect circulating antibodies by means of the complement fixation test in sheep infested with Haemonchus contortus and Trichostrongylus spp. Extraction of worm material at 100°C. for 10 minutes was found to be the most satisfactory method for the preparation of antigens. Potent antigens were prepared from young adult H. contortus, from third-stage infective larvae, and from the eggs. Old mature adult H. contortus yielded antigens of low potency. No significant difference was found between the potency of antigens prepared from male and female adult H. contortus collected from the same sheep. Both adult Trichostrongylus spp. and third-stage infective larvae consistently yielded antigens of high potency. No significant difference was found in the results obtained with larval or adult H. contortus antigens, adjusted to the same potency and tested with natural H. contortus antisera. H. contortus and Trichostrongylus spp. absorbed the antiserum to each other. It was shown that a lipid was an essential constituent of the boiled antigen in the complement fixation reaction with natural antisera. Lipid-free antigens from H. contortus failed to react with natural antisera. The lipid was not antigenic when injected into rabbits. The carbohydrate fraction of H. contortus did not fix complement in the presence of natural antisera and was not antigenic when injected into rabbits. The lipid fraction of a variety of nematode parasites reacted with natural antisera to H. contortus infestation. Similar lipid fractions of two species of trematodes did not react with natural antisera to H. contortus infestation. Normal saline suspensions of the lipid-free material from a variety of helminths showed a greater degree of specificity when tested with artificially prepared antisera than did the lipid fractions.


2012 ◽  
Vol 21 (4) ◽  
pp. 372-378 ◽  
Author(s):  
Raquel Abdallah da Rocha ◽  
Patrizia Ana Bricarello ◽  
Gilberto Pedroso da Rocha ◽  
Alessandro Francisco Talamini do Amarante

This experiment aimed to assess the recovery of infective larvae (L3) of Trichostrongylus colubriformis from Brachiaria decumbens cv. Australiana, Cynodon dactylon cv. Coast-cross and Panicum maximum cv. Aruana. The experimental module comprised six plots, with two plots per herbage species. Larval survival was assessed from autumn to winter, under the effect of two herbage-paring heights (5 and 30 cm). TThe paring was carried out immediately before contamination with faces containing T. colubriformis eggs. The feces and herbage were collected at one, two, four, eight, 12 and 16 weeks after feces had been deposited in the experimental plots. In general, larvae were recovered from both herbage and feces until the 16th week. The longer persistence of these larvae in the environment was probably due to warmer temperatures. The number of L3 recovered from the pasture was not influenced by the height of plants, except for Brachiaria and Aruana herbage in the fourth week. Regarding the concentrations of larvae per kg of dry matter (L3/kg DM), recovery was higher from low pasture in all three herbage species. During the autumn, the development and survival of the T. colubriformis free-living stages were not affected by the different herbage species.


Parasitology ◽  
2002 ◽  
Vol 125 (1) ◽  
pp. 65-70 ◽  
Author(s):  
H. HERTZBERG ◽  
U. HUWYLER ◽  
L. KOHLER ◽  
St REHBEIN ◽  
M. WANNER

The aim of the study was to investigate the longitudinal changes of exsheathment of ovine and bovine 3rd-stage strongylid larvae in an artificial rumen (RUSITEC) and to compare the results with in vivo data obtained from rumen-fistulated sheep. Infective larvae were incubated in nylon mesh bags in the sheep rumen or the RUSITEC apparatus for periods of 1, 6 and 12 h, respectively. The 12 h exsheathment rates in the rumen and the RUSITEC apparatus (in parentheses) were as follows: Haemonchus contortus: 100% (100%), Ostertagia circumcincta: 100% (76%), O. leptospicularis: 100% (100%), O. ostertagi: 53% (59%), Trichostrongylus axei: 100% (100%), T. colubriformis: 37% (36%), Cooperia curticei: 94% (76%), C. oncophora: 95% (89%), Nematodirus filicollis: 0% (N.D.), N. spathiger: 11% (15%), N. battus: 7% (5%), Oesophagostomum venulosum: 17% (9%), Chabertia ovina: 7% (2%), Dictyocaulus filaria: 1% (N.D.). Larvae of Nematodirus spp. and T. colubriformis showed a quick rise of the exsheathment rate 2 h after transfer into the abomasum. These results confirm that exsheathment generally occurs in the part of the gastrointestinal tract immediately anterior to the habitat of the adult parasite. The overall similar course of exsheathment in both systems indicates that the essential stimuli for exsheathment were generated and maintained under in vitro conditions of the artificial rumen. In both systems, the bicarbonate concentration and the pH reflected a similar status of the H2CO3/HCO buffer system, which is known to provide the essential stimuli for larval exsheathment of the abomasal species. These results give evidence that the RUSITEC system represents a valid system for studying the kinetics of exsheathment of strongylid nematodes under in vitro conditions. For 7 of the species investigated the obtained results represent the first data on larval exsheathment in vivo and in vitro.


2018 ◽  
Vol 6 (1) ◽  
pp. 12-16
Author(s):  
Chalinda Koshitha Beneragama ◽  
Ganege Don Kapila Kumara

Drought responses of turf-type Bermuda grass (Cynodon dactylon (L.) Pers.) and Bahia grass (Paspalum notatum Flugge) in relation to their growth, carbon allocation and accumulation of nonstructural carbohydrates were investigated. Seedlings were exposed to a 20 day terminal drought, followed by 20 day recovery with irrigation. Leaf dry matter was lower in water-stressed plants than control plants by the end of drought, but did not differ in roots. For both species, more carbon was allocated towards roots in response to drought. Total nonstructural carbohydrate (TNC) concentration in shoots was increased in drought-stressed plants of both species. However, root TNC concentrations in Bahia grass were decreased after drought. TNC pool sizes also showed a similar variation, hence correlated with TNC concentrations. Bahia grass maintained a better quality than Bermuda grass after the drought, having recorded a higher aesthetic score, higher relative water content and a lower electrolyte leakage. Results suggest that, both species are considerably tolerant to short-term drought though Bahia grass seems more promising.Int. J. Appl. Sci. Biotechnol. Vol 6(1): 12-16


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