Gastrointestinal parasites in young cattle in Norway

Field experiments were carried out for three consecutive years to study the influence of gastrointestinal nematodes in young cattle during their first grazing season. Free-living stages of Ostertagia ostertagi and Cooperia oncophora were found to survive the winter in the pasture in sufficient numbers to cause reduced weight gain and clinical disease, including deaths, in the calves. The symptoms were most pronounced during the first half of the grazing season.The mean weight gain of calves on parasite-free pastures was 48.3, 15.5 and 31.2 kg above those on contaminated pastures during the 3 years.Calves grazing contaminated pasture from the spring onwards, treated with thiabendazole and moved to aftermath in July, showed significantly better weight gain during the last part of the grazing season than calves which remained on the same contaminated pasture. It was, however, suggested that the better grazing conditions were the main cause of the improved weight gain on aftermath.     

Internal parasites of Washington cattle.

The occurrence of internal parasites in Washinton cattle was estimated. During the survey period in 1972 and 1973, more than 3,700 fecal samples from 29 herds and 4 feedlots, and viscera from 55 cattle were examined. The percentage of fecal samples with parasite eggs or oocysts from herds was as follows: oocysts, 77%; "strongyline" eggs, 44%; Nematodirus eggs, 3%; Moniezia eggs, 3%; Fasciola eggs, 2%; Trichuris eggs, 2%; and Dictyocaulus larvae, 1%. The fecal samples from feedlots contained principally strongyline eggs which varied markedly in numbers among groups of cattle in the lots. The predominant parasite in viscera was Ostertagia spp, which was recovered from all of the cattle examined. Other parasites identified in the survey were found less frequently in these examinations. Cattle in dairy and beef operations utilizing irrigated pastures were particularly prone to Fasciola infections, and more strongyline eggs were observed there than in fecal samples from other management systems. Seasonal fluctuations in numbers of strongyline and Fasciola eggs were pronounced.     

Strategies to control internal parasites in cattle and swine

The complex relationship between livestock and their parasites is now much better understood. The pattern of infection and reinfection is a dynamic, but predictable, phenomenon that varies with geographic region, production system and grazing system used. Preventive programs that use anthelmintics offer the most efficient approach for grazing animals and confined species. Control strategies have been designed to prevent worm egg production and to limit parasite contamination and infection at critical periods in animal growth cycles.     

The control of external parasites of cattle

Extract

The important external parasites of cattle in New Zealand include the cattle tick, Haemaphysalis longicornis, which occurs mainly in northern districts, the biting louse, Damalinia bovis, and the long-nosed sucking louse, Linognathus vituli. There are two other lice, Haematopinus eurysternus, and Solenopotes capillatus but they are much less common. The mange mite, Chorioptes bovis, occurs mainly in the winter months and causes lesions on the legs, tail and escutcheon, and in bulls it may cause severe scrotal mange similar to that seen in rams. Demodex folliculorum causes lesions deep in the skin and these constitute a serious problem in the leather industry. Stable flies, Stomoxys calcitrans, are blood suckers and their attacks worry cattle on pasture and in the milking sheds. At milking time they may inhibit milk let-down and the teat cups may be kicked off by restless cows. Warble flies, Hypoderma spp., are seen only in imported cattle and have never become established in New Zealand.     

Impact of internal parasites on beef cattle

Internal parasitism is a pervasive constant that reduces returns in beef cattle production. Parasitism may influence production sufficiently so that data derived investigating performance response will be erroneous. The interaction of internal parasites of cattle with other facets of their lives makes it imperative that more parasite research be done on cattle to consider their impact. Results of trials designed to determine forage production at various stocking densities may not reflect the nutritive value of the forage, but instead the severity of parasite exposure. Relative resistance or susceptibility to certain parasites vary with the breed of livestock and the species of parasite. Extensive work to evaluate the ability of various breeds and sires to influence parasitic numbers has been conducted in sheep but not in cattle. Some parasite trials have ignored the effects of nutrition on the establishment and retention of parasites. This becomes especially important where multiple parasite exposure may occur. Susceptible cattle, even on an optimal diet, will become parasitized, but if reexposed to the same species of parasite, cattle on an optimal diet may be able to resist reinfection, whereas those on deficient diets will not.     

Treatment of external and internal parasites of cattle.

To control parasitic disease in cattle, one first has to determine what parasites he or she is trying to control--nuisance and biting flies in a milking parlor or ticks on range cattle? The determination may be based on geographic location, class of cattle, and their management. After determining what is there, then if the numbers are sufficient, justify treatment. Each livestock producer has a different array of parasites with which to deal, and in some circumstances, parasitic disease is below the economic threshold. Others may have occasional clinical disease associated with parasites, but most have situations in which the potential of economic loss is high enough to justify control.     

Nematode parasites of adult dairy cattle in the Netherlands

Abomasa, blood samples and faecal samples for examination of nematode infections were collected from 125 dairy cows during the period November 1997-October 1998. Of these, 12 had no grazing history and were, therefore, excluded from this study. From the remaining 113, 88.5% had nematode eggs in the faeces. Larval identification of the positive cultures showed that Ostertagia spp. larvae were most frequent (97%), followed by Trichostrongylus spp. (29%), Oesophagostomum spp. (23%), Cooperia punctata (20%), Cooperia oncophora (4%), Haemonchus contortus (2%) and Bunostomum phlebotomum (1%). The geometric mean EPG was 2.4. Two cows excreted larvae of Dictyocaulus viviparus (0.1 and 0.6 LPG resp.). Worms were found in the abomasa of 108 cows (96%). In all these abomasa Ostertagia spp. was present (100%). Trichostrongylus axei was found in 47 abomasa (43.5%) and two cows (2%) were infected with Capillaria bovis. The geometric mean of the total abomasal worm counts was 1743 and of Ostertagia spp. alone 1615. Almost all male worms were Ostertagia ostertagi, only occasionally Skrjabinagia lyrata10,000) total worm burden.Ostertagia specific antibodies were highest in late summer and autumn and lowest in spring and early summer. The same pattern, although not so pronounced, was observed for the serum pepsinogen values. No clear seasonal pattern was found for the Cooperia specific antibodies. Antibodies against D. viviparus were detected in seven cows (6%).     

A survey of gastrointestinal parasites in cattle of southeastern Nigeria

This paper presents the results of a survey of 1021 cattle in the southeastern area of Nigeria during August–October 1990 (wet season) and January–March 1991 (dry season) to study the effects of season, ecological zone, management system, breed and age on the occurrence of gastrointestinal parasites (GIP).

Strongyles (mainly Haemonchus spp.) were the commonest GIP (prevalence 47.8%; 95% CI; 44.8–51%; mean eggs per gram (epg) 387 ± SE 21.3) followed by coccidia (3.6%; 95% CI, 2.6–5%; mean oocysts per gram (opg) 2077 ± 778.4). The prevalence of other parasites encountered was comparatively very low. More infections were present in the wet than in the dry season (P<0.01). Whereas a higher prevalence (P<0.01) of strongyle infection was recorded in nomadic herds, that of coccidia was higher in sedentary herds. The prevalence of strongyle infection was lower in young animals (P<0.05), but they had higher epg (P<0.01) and also higher coccidia prevalences (P<0.01) than adults. Friesian and N'dama breeds under improved management in modern farms had lower strongyle and higher coccidia infections compared with zebu and muturu kept under the traditional management system The distribution of infection by ecological zone did not show any consistent trend, and this was attributed to the uneven distribution of the cattle breeds amongst the different zones.     

Reindeer as hosts for nematode parasites of sheep and cattle

The reindeer husbandry range of Scandinavia overlaps with sheep, goat, and cattle pastures. The aim of this study was to determine whether reindeer are suitable hosts for ovine or bovine nematode parasites, and thus may spread these parasites into the reindeer husbandry regions. To render worm-free, twelve 4-month-old male reindeer calves, six lambs, and six bovine calves were given ivermectin at 200 microg/kg body weight. Five weeks post-treatment, six reindeer calves were each artificially dosed with 10,000 third-stage larvae (L3) of gastrointestinal nematodes derived from sheep, and an additional six reindeer with L3 derived from cattle. Lambs and bovine calves received the same dose of ovine and bovine larvae as reindeer, from the same larval source, respectively. Faecal samples collected on five occasions after the larval dosing revealed that by the fourth week, all reindeer calves, lambs, and bovine calves were infected. Animals were slaughtered on days 40 (reindeer) or 47 (lambs and bovine calves) after the larval dosing. Reindeer calves were most susceptible to L3 derived from sheep. The overall mean intensity of Haemochus contortus, Trichostrongylus axei, and Teladorsagia circumcincta, did not differ between reindeer and sheep; however, early fourth-stage larvae of H. contortus were more abundant in reindeer (p = 0.002). The establishment of bovine-derived Ostertagia ostertagi was similar in reindeer (62%) and bovine calves (57%), but larval inhibition was much higher in reindeer (91%, p < 0.001) than in cattle (31%). Very poor establishment of bovine derived Cooperia oncophora was recorded in reindeer calves (2%) compared with bovine calves (59%). These results show that young reindeer are susceptible hosts to the important gastrointestinal parasites of sheep (T. circumcincta, H. contortus) and cattle (O. ostertagi), as well as being a suitable host for T. axei.     

PCR-based detection of blood parasites in cattle and adult Rhipicephalus appendiculatus ticks

To ascertain the infection rate for tick-borne pathogens in Zambia, an epidemiological survey of Theileria parva, Babesia bigemina and Anaplasma marginale in traditionally managed Sanga cattle was conducted using PCR. Of the 71 native Zambian cattle, 28 (39.4%) were positive for T. parva, 16 (22.5%) for B. bigemina and 34 (47.9%) for A. marginale. The mixed infection rate in cattle was 8.5% (6/71), 16.9% (12/71), 7.0% (5/71) and 2.8% (2/71) for T. parva/B. bigemina, T. parva/A. marginale, B. bigemina/A. marginale and T. parva/B. bigemina/A. marginale, respectively.To predict the risk for transmission of tick-borne pathogens from ticks to cattle, a total of 74 Rhipicephalus appendiculatus ticks were collected from a location where cattle had been found positive for T. parva. Of the ticks collected, 10 (13.5%) were found to be PCR-positive for T. parva. The results suggest that the infection rate for tick-borne pathogens was relatively high in Sanga cattle and that adult R. appendiculatus ticks were highly infected with T. parva.     

Effect of albendazole on gastrointestinal parasites of cattle.

The efficacy of albendazole in removing gastrointestinal nematodes and tapeworms was studied in 16 treated and 16 untreated (control) beef calves. The anthelmintic was administered as an oral drench at a dose level of 5 ml/45.5 kg of body weight (5 mg/kg). Percentage of efficacy against the various genera was: Trichostrongylus axei, Oesophagostomum radiatum, and Moniezia-100.0; Haemonchus placei, Cooperia spp, and Trichostrongylus colubriformis - greater than 99.0; Ostertagia ostertagi -98.3; and Bunostomum phlebotomum -96.2. Efficacy against Trichuris was 20.2. Efficacy against immature nematodes in the abomasum and small intestine was high, 91.9 and 86.4, respectively, but total numbers of nematodes were not large. Efficacy against immature stages in the cecum and remainder of the large intestine was 48.5. Signs of toxicosis were not observed in calves treated with albendazole.     

长沙县牛寄生虫感染情况调查

为了了解长沙县牛感染寄生虫的情况，于2000年7-11月进行了牛寄生虫调查。共对26头牛作了完全剖检，对187头牛进行了直肠取粪检查虫卵和卵囊，对105头牛进行了刮取病料镜检体表寄生虫。共检出体内外寄生虫17种，隶属5纲8目13科15属。