Abattoir condemnation due to parasitic infections and its economic implications in the region of Trikala,Greece

The prevalence of parasitic infections responsible for the condemnation of carcasses and viscera during meat inspection, and their economic implication, was estimated in a year long abattoir survey of 10 277 slaughtered farm animals in the region of Trikala, Greece. The organs examined for the presence of parasitic lesions during meat inspection were: liver and lungs of all animals, rumen of cattle, small intestine of lambs and kids, and muscles of cattle and swine. The parasitic lesions observed in the lungs of cattle, sheep and goats were caused only by hydatid cysts. No hydatid cysts were observed in the lungs of swine. The parasitic lesions observed in the liver of cattle, sheep and goats were as a result of hydatid cysts and flukes of Fasciola hepatica and Dicrocoelium dendriticum, while those of swine were due to milk spots only. Moniezia sp. proglottids were found in the small intestine of lambs only. The prevalence of parasites responsible for the condemnation of marketable organs was low (0.26%). Parasites were responsible for 22% of the total of condemned organs, and their annual cost was 99, 00 GDR (approximately 292 Euros). The parasites most contributing to marketable organ condemnation were hydatid cysts (26%) and D. dendriticum flukes (26%).     

Seasonal changes of gastrointestinal nematode burden in sheep under an intensive grazing system

A study was conducted of the monthly fluctuations of worm burdens and arrested development of gastrointestinal (GI) nematodes in sheep from a commercial farm of the Ebro valley (Spain). Twenty-four previously helminth-free female lambs (permanent lambs) grazed together with a flock of 500 resident ewes for 12 months following a three lambing/2-year reproductive management system. Two helminth-free lambs (tracer lambs) were added to the flock each month and allowed to graze for 4 weeks. Measurements were made of the population of infective larvae on the pasture, and of levels of serum pepsinogen and faecal worm eggs in ewes and lambs. Additionally, post-mortem worm counts from two tracer and two permanent lambs were used to establish the level of infection at monthly intervals. Three generations of parasites were identified in the experiment. The generation derived from eggs deposited the previous autumn gave rise to the first infection of the animals in January and May. This infection had low consequences for the animals, but it signified the initiation of infection and the resumption of the annual cycle of pasture contamination. The second generation, appearing between June and July, was the year's most important source of infection and gave rise to an outbreak of parasitism in permanent lambs. This was indicated by an increase in levels of serum pepsinogen, the appearance of diarrhoea, and an important decrease in lamb growth rates. The third wave of infection, occurring in October and November, there was less impact than the previous one with respect to the level of infection, but it was the origin of the future over-wintering population. Teladorsagia circumcincta was the predominant species, followed by Haemonchus contortus and Trichostrongylus colubriformis. The highest numbers of worm recovered from both the tracer and permanent lambs were observed in July, with average numbers of 7900 and 19,200, respectively.The inhibition phenomenon was more evident in permanent than in tracer lambs, and mainly affected H. contortus as evidenced by populations exhibiting arrested larvae values of over 70% in January and February.Results obtained in this study confirm the epidemiological importance of the over-wintering L(3) generation as the initial source of the animal's infection and the origin of the annual resumption of pasture contamination cycles.     

An epidemiological study of parasitic gastroenteritis in sheep under an intensive grazing system

Romanov X Rasa Aragonesa ewes rearing twins and kept on pasture at a mean stocking density of 35 ewes ha-1 were used to study the epidemiology of parasitic gastro-enteritis under an intensive grazing system on irrigated land in the northeast of Spain. Measurements were made of the population of infective larvae on the pasture, level of serum pepsinogen, faecal worm eggs in ewes and lambs, and lamb growth rates. In addition, postmortem worm counts from "indicator" lambs were used to establish the level of infection at each rotational grazing cycle. Two generations of parasites were identified in the experiment. One of them, derived from the eggs deposited the previous autumn, gave rise to the first infection of the animals in March and April. This was responsible for the first outbreak of parasitism in the lambs. This was indicated by an increase in serum pepsinogen levels, the appearance of diarrhoea and a significant decrease in lamb growth rates. Ostertagia spp., Nematodirus spp. and Trichostrongylus spp. were present. The second generation, which appeared during May, was derived from the eggs of the previous generation and gave rise to an outbreak of parasitism in the lambs at the beginning of May and the middle of June. Haemonchus spp. and Chabertia ovina were present. Under the conditions of this experiment, the overwintering larvae have an important epidemiological significance as the gastro-intestinal nematodes are one of the main limiting factors for developing intensive sheep production systems.     

Seasonal patterns of total and Ostertagia-specific IgE in grazing cattle.

Serum samples, collected monthly from January through December 1988 from 10 cows, their calves, and 10 yearling heifers, were used to determine total and Ostertagia-specific IgE levels. In addition, serum pepsinogen concentration, fecal egg counts, and body weights were measured. The following observations were made. (1) Total and Ostertagia-specific IgE levels followed similar seasonal patterns, being generally highest in the spring. (2) Breed and/or sire effects on total IgE levels were observed, with cattle from Angus-cross lines having higher levels than cattle of the other breeds tested. (3) Based on fecal egg counts, adult populations of Ostertagia ostertagi paralleled circulating IgE levels in the calves.     

The effect of dietary protein levels before turnout on subsequent faecal nematode egg output of grazing sheep in the Joannina region of Greece

The effect of dietary protein levels before turnout on the subsequent faecal egg output of gastrointestinal nematodes was examined in two genotypes of grazing sheep, with or without anthelmintic treatment. Lambs were given a low protein (LP) or a high protein (HP) diet for three months (December to March) until grazing started. Half of the animals in each diet group were given anthelmintic treatment (AT) in March and June. The four groups (LP-AT, LP-NT, HP-AT and HP-NT) each consisted of pure-bred Butsiko and cross-bred Butsiko/Karamaniko lambs and grazed separate plots that were initially parasitologically and nutritionally similar. Faecal egg counts were recorded monthly until the experiment ended in July. Mean faecal counts for strongyle-type eggs were higher in the LP-NT group than all the other groups and higher in the LP than the HP groups indicating that faecal egg counts during grazing were influenced by levels of dietary protein before turnout. This effect was intensified in the absence of anthelmintic treatment. No genotype differences were detected.     

Abattoir Condemnation due to Parasitic Infections and its Economic Implications in the Region of Trikala,Greece

The prevalence of parasitic infections responsible for the condemnation of carcasses and viscera during meat inspection, and their economic implication, was estimated in a year long abattoir survey of 10 277 slaughtered farm animals in the region of Trikala, Greece. The organs examined for the presence of parasitic lesions during meat inspection were: liver and lungs of all animals, rumen of cattle, small intestine of lambs and kids, and muscles of cattle and swine. The parasitic lesions observed in the lungs of cattle, sheep and goats were caused only by hydatid cysts. No hydatid cysts were observed in the lungs of swine. The parasitic lesions observed in the liver of cattle, sheep and goats were as a result of hydatid cysts and flukes of Fasciola hepatica and Dicrocoelium dendriticum, while those of swine were due to milk spots only. Moniezia sp. proglottids were found in the small intestine of lambs only. The prevalence of parasites responsible for the condemnation of marketable organs was low (0.26%). Parasites were responsible for 22% of the total of condemned organs, and their annual cost was 99 500 GDR (～€292). The parasites most contributing to marketable organ condemnation were hydatid cysts (26%) and D. dendriticum flukes (26%).     

Estimation of abomasum strongyle nematode infections in sheep at necropsy: tentative proposals for a simplified technique

Several necropsy techniques are available for estimating the abundance of gastro-intestinal nematodes in abomasum of ruminants. Standardization of techniques is needed to allow accurate comparisons between laboratories. Here we propose a standardized technique for estimating the abundance of worms. We intend to compare the worms' number estimations in lambs and ewes based on contents and washings, to determine the uniformity of worm counts in aliquots, and to estimate the total worm number from washings. The digesta (or "contents") and the washings of the abomasum are treated separately. The worms of each subsample are diluted with water and the total number of worms is estimated on a small volume (aliquots) of these subsamples. The use of aliquots assumes that the worms are uniformly distributed in the whole volume of each subsample. We first confirmed that the use of aliquots is appropriate in most cases. We then show that the use of the washings alone allows a faster and a suitable estimation of the total worm burden for all strongyle species of the abomasum in both ewes and lambs. The evaluation of our necropsy procedure is a first step to a standardized technique which should be improved by validation in other laboratories.     

Seasonal variation of Oestrus ovis-specific antibodies in sheep and goats mixed flocks in Greece

The aim of this survey was to investigate the year-round epidemiological patterns of Oestrus ovis ELISA sero-prevalence in sheep and goats kept together under the same husbandry system in an endemic area of Greece. Twenty-five adult female sheep and 25 adult female goats, coming from a large mixed flock, were randomly selected, eartaged and monthly blood sampled during 1 year period (November 1998-October 1999). Serological prevalence in sheep was 100% all around the year. Mean intensities of specific O. ovis antibodies follow a seasonal evolution with higher mean titers between March and July than in winter. In contrast, the serological prevalences in goats were low specially in winter months (from October to January). No significant difference were noticed in goats antibody levels during the year period. The possible reasons of this difference of O. ovis sero-prevalence between sheep and goats are discussed.     

Comparative study of strongyle infections of cattle and buffaloes in Mindanao, the Philippines

Faecal samples were collected from 500 cattle and 385 buffaloes belonging to backyard farmers from 24 villages in the province of Bukidnon, Mindanao, the Philippines. Strongyle nematode infections were studied on these samples by faecal egg counts and infective larvae differentiation. The effects of animal species and age on the prevalence and intensity of infections were studied. The overall prevalence of strongyle infection was 53% for cattle and 28% for buffaloes. The prevalence decreased with increasing age in both animal species. Faecal egg counts were significantly lower in buffaloes than in cattle. Adult animals had lower egg counts than calves. This age effect was most pronounced in buffaloes. Six genera of strongyle nematodes were identified from the faecal cultures in both animal species, Mecistocirrus, Haemonchus, Trichostrongylus, Cooperia, Bunostomum and Oesophagostomum. The distribution of larvae did not vary much with age.     

Epidemiology of gastrointestinal nematodes of sheep managed under traditional husbandry system in Kashmir valley

The present study was conducted with the objective to investigate the seasonal epidemiological prevalence of gastrointestinal tract (GIT) nematodes in different age groups, sexes and breeds (genotypes) of sheep through necropsy and faecal analysis over a period of 2 years in Kashmir valley, India. A total of 1533 sheep were examined [faecal examination: 1035 (year 1: 561, year 2: 474); necropsy: 498 (year 1: 232, year 2: 266)]. Out of these, 945 (61.64%) were found infected [faecal examination: 697 (67.34%, year 1: 390 (69.51%), year 2: 307 (46.99%); necropsy: 248 (49.79%, year 1: 123 (53.01%), year 2: 125 (64.69%)] with GIT nematodes. The over all prevalence of GIT nematodes in sheep in year 1 was 64.76 and 58.37% in year 2 (P=0.04). The parasites in decreasing order of prevalence (%) in sheep were Haemonchus contortus (59.6); Ostertagia circumcincta (38.0); Bunostomum trigonocephalum (37.7); Chabertia ovina (37.7); Trichostrongylus spp. (33.9); Nematodirus spathiger (29.4); Oesophagostomum columbianum (28.4); Trichuris ovis (23.5) and Marshallagia marshalli (22.1). Season, sex, age, and genotype were the factors that influenced the epidemiological prevalence of GIT nematodes in sheep in the present study. The maximum nematode infection was observed in summer season and lowest in winter (P=0.0005). Local Kashmiri breed was less infected as compared to other genotypes (P>0.05). Lower age groups were more infected than adult animals (P>/=0.05). Prevalence was higher in rams (males) than eves (females) (P>0.05). The present study will initially be of great significance to add to the existing knowledge of the epidemiology of GIT nematodes of small ruminants and the findings will be quite helpful to devise the appropriate control and prophylactic strategies for GIT nematodiasis of sheep reared under the temperate agro-climatic conditions.     

Effectiveness of clean grazing strategies in controlling Haemonchus contortus infections in sheep in the United Kingdom

The effectiveness of clean grazing systems for controlling the sheep abomasal parasite Haemonchus contortus under experimental conditions was monitored for a grazing season in ewes and lambs carrying either benzimidazole-susceptible or resistant populations of the parasite. Both preventive and evasive strategies failed to give effective control of H contortus. Lambs grazing with ewes that had received no anthelmintic showed clinical signs of haemonchosis by early July. Lambs from ewes dosed with a benzimidazole (mebendazole) before turn out, developed clinical signs of haemonchosis later in the season. The presence of anthelmintic resistant genotypes had a significant effect on the appearance of clinical signs, and on the epidemiology and control of disease. It was concluded that alternative worm control strategies will be required for the effective control of H contortus in the United Kingdom.     

The efficacy of fenbendazole in the control of immature strongyle infections in ponies

The efficacy of fenbendazole against immature stages of Trichonema spp., Strongylus vulgaris and Strongylus edentatus was evaluated. Naturally infected 6 to 12 month old ponies were given single, oral doses of 0, 15, 30 and 60 mg/kg of body weight. A dose response relationship was noted between increasing dose levels and efficiency against larval trichonemes and migrating stages of S. vulgaris and S. edentatus. Dose levels of 30 mg/kg and higher removed 93 per cent of mucosal stages of Trichonema spp., while doses of 60 mg/kg removed 83 per cent and 89 per cent of the migrating larvae of S. vulgaris and S. edentatus respectively.     

高寒草地放牧系统锰的季节变化及盈缺分析

对青海三角城种羊场夏（6月中旬）、秋（9月中旬）、冬（12月中旬）3季的水、土壤、牧草、绵羊被毛、血液、组织器官中锰含量进行了调查采样分析,结果表明,土壤锰含量夏季高于秋冬两季,都处于正常范围的下限,牧草和绵羊组织器官（肝脏除外）中锰为夏季>秋季>冬季,冬季则处于临界缺乏水平。从整个土壤-牧草-畜体生态体系来看,青海三角城种羊场绵羊冬季处于临界缺锰的营养状况。     

Epidemiological patterns of gastrointestinal and lung helminth infections in grazing calves in The Netherlands

The patterns of gastrointestinal and lung helminth infections in grazing calves were studied in two small grazing experiments carried out between May and October in 1985 and 1986, respectively, at Utrecht State University. For lungworm a very rapid translation of infective larvae was seen in both experiments, resulting in a rapid build-up of the worm burdens, and in July the second generation of Dictyocaulus caused husk. After the end of patency for lungworm, in the beginning of August, a rapid decrease in pasture infectivity, measured by pasture larval counts and worm counts of tracer calves, was observed. For the gastrointestinal nematodes the translation of infective larvae was much slower as a distinct 'midsummer increase' of pasture infectivity was not seen before the end of July. The worm counts of the tracer calves and the pasture larval counts showed that these larvae remained on pasture much longer than the lungworm larvae. As in Dictyocaulus, patency stopped in August-September in Nematodirus but not in Ostertagia and Cooperia, indicating a slower rate of development of immunity in both latter genera. In contrast to lungworm, the results indicate a clear and predictable seasonal pattern for gastrointestinal helminth infections.     

Parasites in sheep grazing on Kikuyu (Pennisetum clandestinum) pastures in the winter rainfall region

Regular worm counts were done post-mortem on sheep that had grazed on Kikuyu pastures at the Elsenburg Research Station near Stellenbosch, a winter rainfall region. Major species were Trichostrongylus colubriformis, Trichostrongylus axei, while Ostertagia circumcincta was usually present in large numbers. Minor species were Haemonchus contortus, Nematodirus spathiger, Dictyocaulus filaria, Oesophagostomum venulosum, Trichuris spp., Chabertia ovina and larvae of the arthropod Oestrus ovis. Muellerius capillaris caused the formation of nodules in the lungs but were not counted. The trial started in April 1982 and was concluded in March 1984. One hundred and four sheep died or were slaughtered and 99 were examined post-mortem during this period. Total worm burdens rose to a peak of 88,763 (range 67,281-124,735) worms in March 1983, i.e. sheep mortality was such that the flock had to be treated with an anthelmintic in April 1983 to prevent further losses. Kikuyu pastures provide shade, form an excellent mat, the humus layer under the grass retains moisture and is an excellent incubator for preinfective larvae and a protector for infective larvae. If these qualities are combined with more than 100 mm of rain in spring and summer, Kikuyu pastures are a paradise for the free-living stages.     

松嫩平原农牧交错区绵羊放牧系统粗饲料的链烷特征

链烷是一类普遍存在于植物表皮蜡质中的饱和直链碳氢化合物,应用链烷技术可以测定放牧动物采食量和食性组成,本试验采用气相色谱法对松嫩平原农牧交错区绵羊放牧系统(人工和天然羊草草地、玉米和大豆农田残茬)中主要粗饲料的链烷含量和特征进行了分析,以期为农牧交错区放牧绵羊营养研究提供基础数据。试验结果表明,松嫩平原草地和农田残茬饲料资源所含的链烷具有明显的种间特征,在C₂₁~C₃₅链烷之间,奇数链烷的含量总体上高于偶数链烷的含量,不同生长时期的全株羊草、5月份的野稗和碱蒿、5和8月份的苣荬菜、8月份的狗尾草、大豆和玉米残茬的茎、叶、荚中均以C₃₁含量最为丰富,马蔺C₂₉含量最为丰富,而羊草穗、7月份野稗、8月份的碱蒿以C₂₇含量最为丰富。     

Gastrointestinal nematode infections in small ruminants under the traditional husbandry system during the dry season in southern Ethiopia

A cross-sectional study was conducted from November 2008 to February 2009 to investigate the prevalence and intensity of infection and risk factors of gastrointestinal (GI) nematodes in small ruminants kept under the traditional husbandry system in two districts in southern Ethiopia. Faecal samples collected from a total of 510 small ruminants (284 sheep and 226 goats) and analysed by a modified McMaster technique revealed that 222 animals (43.5%) were found to be infected with one or more GI nematodes. Five identical genera of nematodes were found in both sheep and goats, which in order of predominance were Haemonchus (56.3%), Trichostrongylus (39.6%), Oesophagostomum (22.9%), Trichuris (21.6%) and Bunostomum (10.4%). No significant (p > 0.05) differences were observed between sheep and goats proportions except for Trichuris (p < 0.05). In both sheep and goats, most of the animals were heavily infected showing faecal egg counts (FECs) above 1,200 epg. Sheep had a significantly (p < 0.05) higher mean FEC than goats. In sheep and goats, both the prevalence of GI nematodes and mean FEC were significantly (p < 0.001) associated with body condition score and faecal consistency but not with district, sex and age (p > 0.05 for each factor). In conclusion, the observation of a strong association of GI nematodes with poor body condition coupled with heavy intensity of infection in the majority of infected animals and an abundance of nematode genera of widespread economic and pathological significance warrants the institution of appropriate control measures that should necessarily include improvement of the nutritional status of the animals.