The Survival of Infective Larvae of Ostertagia ostertagi and Cooperia oncophora in Hayloft-dried Grass*

2010 ◽  
Vol 21 (8) ◽  
pp. 641-645 ◽  
Author(s):  
Lennart Persson
Keyword(s):  
Ostertagia Ostertagi ◽  
Infective Larvae ◽  
Cooperia Oncophora

The differentiation of the infective larvae of some common nematode parasites of cattle

1953 ◽  
Vol 1 (2) ◽  
pp. 223 ◽  
Author(s):  
RK Keith
Keyword(s):  
Differential Diagnosis ◽  
Body Length ◽  
Haemonchus Contortus ◽  
Body Width ◽  
Ostertagia Ostertagi ◽  
Infective Larvae ◽  
Nematode Parasites ◽  
Cooperia Oncophora

Studies are reported on the differential diagnosis of the infective larvae of Strongyloides papillosus, Haemonchus contortus, Ostertagia ostertagi, Trichostrongylus axei, Cooperia oncophora, C. punctata, C. pectinata, Bunostornum phlebotomum, Nematodirus sp., and Oesophagostomum (Bosicola) radiatum, all of which occur in cattle in Queensland. These larvae can be readily identified by the length and shape of the tail, assisted by body length, body width, certain head and tail structures, and by the presence or absence of a sheath. A key for the identification of the larvae is given. Photographs of the larvae are also provided to assist identification.

Arrested development of Ostertagia ostertagi and Cooperia oncophora

1975 ◽  
Vol 85 (1) ◽  
pp. 133-138 ◽  
Author(s):  
J.F. Michel ◽  
M.B. Lancaster ◽  
C. Hong
Keyword(s):  
Arrested Development ◽  
Ostertagia Ostertagi ◽  
Cooperia Oncophora

Experimental infections withCooperia oncophora(Railliet, 1918) in calves. Results of single infections with two graded dose levels of larvae

Parasitology ◽  
1979 ◽  
Vol 78 (3) ◽  
pp. 331-342 ◽  
Author(s):  
F. H. M. Borgsteede ◽  
J. Hendriks
Keyword(s):  
Small Intestine ◽  
Weight Gain ◽  
Worm Burden ◽  
Great Part ◽  
Clinical Signs ◽  
Larval Stages ◽  
Infective Larvae ◽  
Cooperia Oncophora ◽  
Dose Levels ◽  
Haematological Data

SUMMARYTwo experiments were carried out in which calves reared parasite-free were infected with a single dose of 3rd-stage larvae ofCooperia oncophora. In the first experiment the calves received 20000 or 200000 infective larvae and they were autopsied 28 or 56 days after the infection. In the second experiment the doses were the same but the animals were killed 14, 84 or 140 days after infection. If a dose of 20000 was given, clinical signs were never observed, while at a dose level of 200000 the weight gain was less on 56 and 84 days after the infection compared with the low-infected groups or the control animals. After 140 days the differences in weight gain were compensated. Faecal egg output was higher in the 200000 groups only in the first period of patency, thereafter the calves in the 20000 groups produced more. No obvious differences between the two infection levels were observed with regard to the haematological data. In the low-infected groups worm counts were only slightly lower when the results after 28 days were compared with those after 56 days. Also, the worm numbers after 14 days were almost equal to those after 84 days, while at 140 days 1 animal still had the same number, the other one had lost its worm burden. In the high-infected groups the worm loss was much quicker. After 28 days a great part of the population had already been lost. Obviously, at the 200000 level the reaction of the host against the parasite was much stronger. Adult worms were expelled at a higher rate than early 4th-larval stages. In the first experiment worm measurements revealed differences between the length of females, males and spicules of males, these being significantly longer in the low-infected groups. Analysis of the distribution of worms over the small intestine showed that in the low-infected groups worms were mainly restricted to the first 6 metres. In the high-infected groups the worm population was distributed more evenly over the whole small intestine.

Sign in / Sign up

Export Citation Format

Share Document