Pasture Contamination Research Articles

Histological changes of oocytes of the cattle tick Rhipicephalus microplus (Canestrini, 1888) treated with copper solutions

Infections caused by the ectoparasite Rhipicephalus microplus can cause major health problems in cattle, including death. Tick control is regularly made using a range of acaricide products. As a consequence, tick populations have been heavily selected for drug resistance. The objective of this work was to determine the in vitro efficacy of copper chloride and sulfate (CuCl2 and CuSO4) solutions against R. microplus. The adult immersion test (AIT), which measures the egg-laying and egg-hatch effects, was used for the Cu-II solutions at 30, 60, 120, 240, 480, and 1000 mM, in triplicates. Distilled water and the combination of cypermethrin 20% and chlorpyrifos 50% were used as controls. Histological sections were performed from the ovaries of adult engorged female ticks treated with 240, 480, and 1000 mM of CuCl2 and CuSO4. We have established a histological index of the damage caused by the solutions to the tick oocytes. The overall efficacy (egg laying & egg hatch) for CuCl2 and CuSO4 was 81.3, 82.5, 89.8, 84.5, 100.0, and 100%, and 61.7, 43.4, 62.5, 93.1, 100.0, and 98.5% respectively. Smaller oocytes were found in the Cu-II groups compared to the negative control. The histological data showed a concentration-dependent degenerative lesion of oocytes, described as cytoplasmic vacuolation and nuclear disorganization. The combination of cypermethrin and chlorpyriphos showed 100% efficacy. Cu-II solutions showed in vitro efficacy against adult engorged ticks being particularly harmful to oocytes. Thus, bioactive metals could be a complementary biofriendly treatment to control R. microplus and these injuries could be responsible for preventing egg hatch, and reducing pasture contamination. Safety studies are underway demonstrating the Cu-II potential in naturally infected cattle and their persistence in the environment.

Hide ‘n seek: individual behavioural responses of cattle excreting different amounts of nematode eggs—potential threshold for pasture contamination assessment

The aim of this study was to investigate how the activity of cattle under natural grazing conditions is related to their individual parasite contribution (IPC). Potentially, the individuals contributing the most to the contamination of the pasture with gastrointestinal nematodes (GIN) could then be identified and selectively treated based on sensor data thresholds. A total of 58 steers of the dairy breeds Swedish Red (SR, n = 19) and Swedish Holstein (SH, n = 39) were used for sensor-based data collection that lasted for a total of 10 weeks from 4 May to 13 July 2022. All steers were inoculated with a priming dose of nematode larvae and weighed in conjunction with the pasture release. The animals were then divided into four experimental groups and treated with ivermectin (IVM PO, Boehringer Ingelheim, 0.5 mg/kg BW) at different intervals to obtain an exposure contrast (Group A was left untreated, Group B/IVM PO-4w was treated after 4 weeks, Group C/IVM PO-8w was treated after 8 weeks, and Group D/IVM PO-4&8w was treated after 4 weeks and then after 8 weeks). The steers were weighed on four further occasions, during which faecal samples were also taken for parasite testing. Activity data were collected using leg-mounted IceQube sensors and body weight data and faecal samples were collected bi-weekly. The new threshold metric (IPC) was proposed for individuals with different faecal egg count (FEC) levels [NO (no contribution) <20 EPG, LO (low contribution) = 20–150 EPG, ME (medium contribution) = 150–250 EPG, and HI (high contribution) ≥250 EPG] The effects of IPC on activity patterns were analysed stepwise using a Generalised Estimating Equations model implemented in Python programming language. Results showed significant effects of different IPC values on motion index and number of steps taken (adjusted p-value of 0.008, 0.018, 0.041, and 0.001 for individuals with NO, LO, ME, and HI IPC values, respectively). There were some breed effects on the average number of steps and minutes spent lying. The results also provide alternative threshold methods aimed at finding more sustainable ways of using anthelmintics and integrating individual data into future parasite control strategies.

An alien parasite in a changing world - Ashworthius sidemi has lost its traditional seasonal dynamics.

A non-native nematode Ashworthius sidemi has emerged in captive fallow deer in Central and Eastern Europe over the last decade. Although this parasite has been spreading in the wild outside it's native distributional range and colonising local European host species since the middle of the last century, limited information has been published on the seasonality of A. sidemi and its susceptibility to anthelmintics. To address this knowledge gap, we conducted a study to investigate seasonal dynamics of the non-native parasite in the current Central European climate conditions. We collected freshly voided faecal pellets at four-week intervals from February 2018 to February 2020 at a fallow deer reserve with a known history of A. sidemi presence. The faecal pellets obtained were pooled after each site visit (n = 25) and coprocultured to obtain the third stage larvae of trichostrongylid nematodes at monthly intervals. Total genomic DNA was extracted from the recovered larvae. Using real-time multiplex PCR, A. sidemi DNA was detected in 17 out of 25 larval samples (68% prevalence). During the monitoring period, the annual administration of ivermectin based premix (Cermix) took place in January 2018, 2019, and 2020, and additionally a mixture of rafoxanide and mebendazole (Rafendazol) was administered once in spring 2019. The probability of parasite presence was significantly influenced by the time since the drug administration (p = 0.048) and the mean temperature at the location (p = 0.013). Larval samples negative for A. sidemi were always identified shortly after the drug administration. However, rapid pasture contamination by the parasite eggs from two to three months after Cermix administration and within one month after Rafendazol administration suggest only a short-lived efficacy of both administered drugs. The abundance of A. sidemi DNA was positively affected by mean temperature (p = 0.044) and remained relatively stable throughout the monitoring period, with the highest peak in August 2018 and 2019. Pasture contamination with A. sidemi eggs occurred almost all year round, with the exception of the beginning of 2018, 2019, and 2020. These findings indicate adaptation of a non-native parasite to the current climatic conditions of the Czech Republic resulted in negligible seasonal patterns of parasite egg shedding.

Combined effects of Limonene and Ivermectin on P-glycoprotein-9 gene expression of lambs Infected with Haemonchus contortus

Although ivermectin (IVM) has a wide spectrum and long half-life, its frequent use as an anthelmintic for the last 42 years led to its worldwide tolerance by Haemonchus contortus. We evaluated the combination of limonene (LIM), a P-glycoprotein (Pgp) modulator, with IVM in lambs infected with a multidrug-resistant H. contortus. Twenty-four male Dorper lambs were artificially infected with two doses (seven days apart) of 8000 infective larvae of a multidrug-resistant isolate of H. contortus. The infection was patent 25 days later. Fifteen days before treatment with IVM (DAY –15), animals were divided into 4 groups: Infected-untreated control (CTL), IVM, LIM, and LIM+IVM. From DAY –15 to DAY + 14, groups LIM and LIM+IVM received 200 mg/kg of body weight/day of LIM via oral. On DAY 0, a single dose of IVM at 200 µg/kg of body weight was administered orally to groups IVM and LIM+IVM. On DAY + 7 and DAY + 14, fecal egg counts (FEC) were performed and on DAY + 14 animals were euthanized for total worm count (TWC), worm length, fecundity of females, and Pgp-9 gene expression. On DAY + 7, group LIM+IVM had 96.29% efficacy based on Fecal Egg Count Reduction TEST (FECRT) and a highly significant reduction in FEC (P = 0.0005) when compared to CTL. On DAY + 14, the efficacy of LIM+IVM was 82.87% on FECRT, although no differences were found among groups for FEC, TWC, worm length, or Pgp-9 gene expression. Female worms from the CTL group had higher egg counts in their uterus when compared to LIM. No differences were found for hematological or biochemical parameters, body weight, or weight gain among groups. Thus, LIM given daily at 200 mg/kg was safe for animals and, when combined with IVM, decreased egg shedding and could reduce pasture contamination, although it was unable to kill multidrug-resistant H. contortus.

Correlation of Faecal Egg Counts with Clinical Parameters and Agreement between Different Raters Assessing FAMACHA©, BCS and Dag Score in Austrian Dairy Sheep.

Gastrointestinal nematodes, most notably trichostrongylids, are known to cause significant losses in sheep production. Previous studies have shown that monitoring parameters (e.g., FAMACHA©, BCS, dag score) change with increasing egg excretion. These parameters are well known and frequently used for targeted selective treatment. Based on the willingness to participate in this study (based on a previous questionnaire distribution among sheep farmers in Austria) we investigated the associations between faecal egg counts and the FAMACHA©, BCS, and dag scores of 1195 dairy ewes. Faecal samples were analysed using the Mini-FLOTAC technique I and larval culture. Three raters assessed the FAMACHA©, BCS, and dag scores in sheep to calculate the inter-rater agreement and intraclass correlation coefficient. The responses to the questionnaire of 23 farms were used for the evaluation, of which 16 farms were visited. Trichostrongylid eggs were detected in 95% of the faecal samples. The BCS was negatively correlated with the eggs per gram of faeces (EpG) (r = -0.156; p < 0.001) and the FAMACHA© score was slightly positively correlated with EpG (r = 0.196; p < 0.001). A small proportion of sheep (25%) shed the majority of eggs (47% to 84%). A moderate to good agreement for the parameters was found between the raters. In conclusion, the clinical parameters showed only weak correlations with faecal egg counts, and we confirmed that a minority of the flock is responsible for the majority of the pasture contamination with trichostrongylid eggs. Clinical raters should be trained before a study to increase the agreement between them.

Epidemiology of infection with lung worms in sheep in Tikrit city, Salah Al Deen province

1.The study area spend Tikrit in Salah Aden province, and followed him from the aspects and villages and tubing such as Al-Alam district , Hawi Albu-Ajeel, Al-Naama areas, a series Hamrin mountains east of the Tigris River, stretching from north to south and Al Awja district, Aouinat, Mahzm, Al-Hamra and al-Jazeera to Lake Tharthar west of the Tigris River.&#x0D; &#x0D; were collected 1298 fecal sample from sheep and goats, of which 734 samples of sheep and 564 samples of the goats as "the beginning of the month of January until the end of the first December for the year (2014), have been examined and these samples to look for larvae of the lung worms in sheep of five races are Dictyocaulus, Muellerius, Protostrongylus, Cystocaulus and Neostrongylus test result showed the following:&#x0D; &#x0D; A.The effect of infection for the seasons of the year. The highest proportion of infection in the early winter (December first) while the lowest rate of infection in the mid-summer (July).&#x0D; &#x0D; Ratio of infection for genus lung worms. The rate of infection genus Dictyocaulus 21.5%, the highest rate while the rate of infection genus Neostrongylus 2.1%, representing the lowest percentage of infection among the five races the rest of the races where concatenated infection rates downward Muellerius 13.6% and then Protostrongylus 10.9 % then Cystocaulus .&#x0D; Ratio of infection single and mixed. Single scored infection rate of 13.79% and mixed infection rate of 15.48% during the year (2014).&#x0D; Show that the proportion of infection to the search area along the Tigris River is higher than the rest of the other search areas due to contamination of pasture and increase the availability of moisture and Alamadaiv moderation in all seasons of the year.&#x0D;

Faecal egg counts and nemabiome metabarcoding highlight the genomic complexity of equine cyathostomin communities and provide insight into their dynamics in a Scottish native pony herd

Understanding the composition of gastrointestinal nematode communities may help to mitigate or exploit parasite adaptations within their host. We have used nemabiome deep amplicon sequencing of internal transcribed spacer-2 (ITS-2) ribosomal DNA to describe the temporal and host species composition of gastrointestinal nematode communities following sampling of six Scottish ponies across 57 months. In the absence of parasite control, each horse showed seasonal trends of increases and decreases in faecal egg counts, consistent with the epidemiology of equine strongylid parasites, however, the composition of parasites within individuals changed over time. Sixteen presumptive strongylid species were identified in each of the horses, 13 of which were distributed in a complex clade together with small numbers of amplicon sequences which could not be classified beyond the Cyathostominae subfamily level. Egg shedding of seven trichostrongylid species, which had previously been identified in co-grazed Soay sheep, was identified during the early spring. Faecal egg counts and the percentage of amplicon sequences assigned to each gastrointestinal nematode species were combined to describe their relative abundance across both host and time. Significant differences in species diversity between horses and between months were observed, being greatest from March to May and least from October to December. The magnitude of the individual horse effect varied between months and, conversely, the magnitude of the seasonal effect varied between individual horses. The most abundant gastrointestinal nematode in each of the horses was Cylicostephanus longibursatus (46.6% overall), while the abundance of the other strongylid species varied between horses and relative to each other. Patent C. longibursatus infections over the winter months might represent a genetic adaptation towards longer adult worm survival, or a lower rate of developmental arrest in the autumn. This study provides insight into highly complex phylogenetic relationships between closely related cyathostomin species; and describes the dynamics of egg shedding and pasture contamination of co-infecting equine gastrointestinal nematode communities. The results could be applied to determine how climatic and management factors affect the equilibrium between hosts and their parasites, and to inform the development of sustainable gastrointestinal nematode control strategies for different host species.

Castor bean cake for the control of parasites in pasture-finished sheep.

The purpose of this study was to evaluate castor bean cake as alternative input in the control of gastrointestinal parasites in sheep raised on irrigated pasture under continuous stocking. The treatments consisted of sheep supplemented with standard diet and pasture fertilized with urea; sheep supplemented with alternative diet and pasture fertilized with urea; sheep supplemented with standard diet and pasture fertilized with in natura castor bean cake; and sheep supplemented with alternative diet and pasture fertilized with in natura castor bean cake. A randomized complete block design (CBD) was used, with 16 replications (sheep), with repeated measures over time, the plots being the treatments, and the subplots the collection times. Infective nematode larvae in the pasture (L3.g DM−1), number of eggs per gram of feces (EPG), globular volume (GV), and total plasma protein (TPP) were evaluated. For adult gastrointestinal parasite counts, CBD was also used with six replications. Except for FAMACHA© grade, all variables had effect (P < 0.01) of the time factor. The average number of L3.g DM−1 and EPG were 126 and 841, respectively, with no effect (P > 0.05) of the treatment factor. The values observed for GV and TPP were higher than 25.9% and 6.4 g·dL−1, respectively, which were considered normal. As organic fertilizer, the fractionated application of in natura castor bean cake does not reduce the contamination of pastures by nematode larvae. The evaluated feeds improve the resilience of the sheep to infection by gastrointestinal parasites. The treatments using castor bean cake reduced the adult parasites present in the abomasum of sheep.

Tracking gastrointestinal nematode risk on cattle farms through pasture contamination mapping

Gastrointestinal nematode (GIN) parasites in grazing cattle are a major cause of production loss and their control is increasingly difficult due to anthelmintic resistance and climate change. Rotational grazing can support control and decrease reliance on chemical intervention, but is often complex due to the need to track grazing periods and infection levels, and the effect of weather on larval availability. In this paper, a simulation model was developed to predict the availability of infective larvae of the bovine GIN, Ostertagia ostertagi, at the level of individual pastures. The model was applied within a complex rotational grazing system and successfully reproduced observed variation in larval density between fields and over time. Four groups of cattle in their second grazing season (n = 44) were followed throughout the temperate grazing season with regular assessment of GIN faecal egg counts, which were dominated by O. ostertagi, animal weight and recording of field rotations. Each group of cattle was rotationally grazed on six group-specific fields throughout the 2019 grazing season. Maps and calendars were produced to illustrate the change in pasture infectivity (density of L3 on herbage) across the 24 separate grazing fields. Simulations predicted differences in pasture contamination levels in relation to the timing of grazing and the return period. A proportion of L3 was predicted to persist on herbage over winter, declining to similar intensities across fields before the start of the following grazing season, irrespective of contamination levels in the previous year. Model predictions showed good agreement with pasture larval counts. The model also simulated differences in seasonal pasture infectivity under rotational grazing in systems that differed in temperature and rainfall profiles. Further application could support individual farm decisions on evasive grazing and refugia management, and improved regional evaluation of optimal grazing strategies for parasite control. The integration of weather and livestock movement is inherent to the model, and facilitates consideration of climate change adaptation through improved disease control.

Diversity, prevalence, and intensity of gastrointestinal helminth infections in migratory, resident, and sedentary plains zebras (Equus quagga) in Masai Mara National Reserve and Lake Nakuru National Park, Kenya.

The diversity, prevalence and intensity of parasitic infections are influenced by factors such as movement patterns and land area available to the host. Zebras are known to harbour various genera of gastrointestinal helminths and facilitate parasite movement across large geographic areas through migration. Despite the harmful effects of helminths and their consequences on host population dynamics, little is known regarding helminth infection patterns in migratory, resident, and sedentary zebras. This study compared the diversity, prevalence, and intensity of helminth infections in zebras with different host movement patterns and space availability. Faecal samples were collected from migratory, resident, and sedentary groups of zebras between 2014 and 2015 and screened for helminth infection. They were infected by diverse groups of helminths including nematodes, trematodes and cestodes with the most prevalent being strongyle type nematodes. No significant difference in the diversity and prevalence was observed between the "three groups". Larvae were also recovered and identified species, cyathostomes, Strongylus edentatus, S.vulgaris, S. equinus, and Trichostronglus in order of abundance. The intensity of infection with the strongyle type nematodes, was highest in the migratory, then sedentary and lowest in resident zebras. It is plausible that the migratory zebras have higher energy demands and poor nutrition, resulting in reduced immune function hence high nematode burdens. Similarly, the sedentary population had high nematode burdens possibly due to high pasture contamination and depressed immunity due to the artificially restricted movement. The latter observation is particularly important in the design and size of sanctuaries in relation to parasitism.

Study on Prevalence of Equine Strongylosis and Associated Risk Factors in and Around Guder, Oromia, Ethiopia

A Cross sectional study was conducted from April to June 2019 in and around Guder town to estimate the prevalence of strongyle infection and assess associated risk factors in the study area in donkeys, mules and horses. A total of 384 animals were randomly selected from different peasant associations in the study area and examined during the study period. Fecal examination for the detection of strongyle eggs was performed using floatation technique. The overall prevalence of strongyle parasites was 25.26% (97 from 384) with 14.58% in donkeys, 6.77% in mules and 3.9% in horses. The study has also showed variation in prevalence of strongyle parasites among different body condition scores and among purpose, higher prevalence was recorded in poor body condition (16.4%) and draft (14.06 %). The risk factors; body condition and purpose status of the equines in the study area were significantly associated with the occurrence of strongyle parasites (p&lt;0.05). In conclusion the current study revealed that stronglosis was found to be the major problem in the study area; hence Strategic deworming and minimizing overworking and extensive open grazing should be implemented to reduce pasture contamination.

Monitoring environmental conditions on the speed of development and larval migration of gastrointestinal nematodes in Urochloa decumbens in northeastern Brazil.

The study aimed to evaluate the speed of development of gastrointestinal nematodes (GIN) eggs to infective larvae (L3) and its migration under effect of meteorological variables: temperature, rainfall, relative humidity, solar radiation to Urochloa (=Brachiaria) decumbens grass pasture during rainy season, from June to September 2019, and dry season, October to March 2020, in Recôncavo baiano region of Bahia state, Brazil. Monthly, fecal samples obtained from goats with recurrent GIN infection were deposited in six plots of one square meter. In +7, +14 and+21-days post-deposition, lower and upper strata grass (0-15 and>15cm, respectively) and remaining feces were collected and submitted to Baermann's technique modified to perform larval count and identification. Meteorological data were obtained from a local weather station database. The log-transformed larval count results were analyzed regarding the collection day effect, stratum effect, comparing the means by Tukey's test (p<0.05). Multivariate regression analysis and correlation of meteorological variables with larval counts was performed. In the rainy season, the largest proportion of recovered L3 was concentrated in +7-days post-deposition in the months of June and July, both in the remaining feces and herbage samples, while in August development took place more slowly, after +14-days post-deposition. During the dry season, L3 development only occurred after the first collection in January and February. Lower strata had higher proportion of recovery than in upper strata. Negative correlation was found for solar radiation. Greater rainfall in the rainy season compared to dry season was a favorable condition for high contamination of grass samples. However, reduced vertical migration to upper strata may have been influenced by low temperatures during the rainy season. Regarding the genera present in the fecal samples used in the experiment were found Haemonchus sp., Trichostrongylus sp. and Oesophagostomum sp. Thus, it is possible to conclude that in the region of the study, during the rainy season, there is a rapid larval development and the L3 are able to migrate more effectively to the grass. On the other hand, in the dry season, larval development tends to be slower, with less migration to the grass. Solar radiation can be useful for predicting months with the highest risk of infection. Therefore, prophylactic measures should be employed in goat herds during the rainy season whilst natural reduced pasture contamination in the dry season may favor animal maintenance for a longer time.

A model for the development of the free-living stages of Ostertagia leptospicularis, used in conjunction with on-farm egg count data, to estimate sources of pasture contamination on New Zealand red deer (Cervus elaphus) farms

Farmed red deer face challenges from nematode parasites, primarily the pulmonary species Dictyocaulus eckerti and the complex of Ostertagiinae nematodes in the abomasum. Previous investigations on New Zealand deer farms identified limited seasonality in faecal egg and larval output in all stock classes, however, this does not indicate the key times of year those eggs develop into infective-stage larvae, and subsequently contribute to infection risk. A simple temperature-driven model was developed for the free-living stages of a representative deer-specific Ostertagiinae species; Ostertagia leptospicularis. The model was then validated using development data generated from seasonal plot trials. Using faecal egg counts and animal numbers from the previous monitoring study, and local weather data from each of the sampling farms, the relative contribution of each stock class to infective third-stage larvae population on pasture was estimated for each month of the year (2018–2019). The mixed-age adult females were the primary source of infective larvae on most of the sampled farms, principally due to their numerical dominance (i.e., venison breeding farms). The frequent anthelmintic use in the youngest stock class (< 12 months old) on some farms limited their output of eggs and hence their contribution to pasture infestation with infective larvae. However, the trends of larval development on pasture differed between the farms (due to local climate), and between the sampling years (2018–2019). Therefore, calendar-based application of anthelmintics to older stock is not recommended, as contribution to pasture contamination is multifactorial. The study provides a better understanding of deer parasite epidemiology on which to base improved management practices.

ANTHELMINTIC FOR MIXED PARASITOSIS

The antiparasitic program, which provides specific treatment and prevention regimens for fascioliasis, dictyoculosis, strongylatosis of the gastrointestinal tract and other parasitoses is the most effective link aimed primarily at removing helminths and preventing infection. Taking into account the total economic damage when helminthofauna in animals is represented simultaneously by parasitic species, it is necessary to be armed with anthelmintics of a wide spectrum of action. With their help, it is possible to carry out preventive measures most effectively and forced deworming, taking into account the epizootic situation and the present background of pathogens of invasions in the farm. As a result of the research, the higher efficiency and prospects of using Santel in the long-term forecast and Santomectin compared with the basic drugs of a narrow spectrum of action. Santomectin, acting on the larval and adult stages of fascioles, prevents the development of acute fascioliasis, as well as its transition to a chronic form; prevents the release of eggs of fascioles into the external environment, chronically ill animals, all this has the best effect on the epizootic situation, especially before being driven to pasture, and ultimately on the health and productivity of animals; it allows solving the problem of mixed parasitosis that cause the greatest economic damage; anthelmintics that are not active for larval stages of fascioles, slightly prevent contamination of pastures with trematodes, for the destruction of which repeated treatments are necessary

Dung beetle community composition affects dung turnover in subtropical US grasslands.

An important service in many ecosystems is the turnover and degradation of dung deposited by cattle. Dung beetles are the primary group of insects responsible for dung turnover, and factors affecting their abundance and distribution thus impact dung degradation. Lands lost to grazing due to dung buildup and pasture contamination total millions of acres per year in US pastures.We evaluated the structural differences in dung beetle assemblages in natural grasslands versus a managed agroecosystem in subtropical southeastern Florida (USA). We measured the direct effect of dung longevity when dung beetle fauna normally inhabiting dung pats were excluded.Our results indicate dung beetle abundance, functional diversity, and species richness have a substantial impact on the rate of dung turnover in subtropical pastoral lands with ~70% of dung removed from the soil surface after three months. Functional diversity and evenness did not have a significant positive effect on dung removal in managed, versus natural grasslands demonstrating a strong relationship between dung beetle assemblage composition and delivery of a key ecological process, dung degradation.We suggest the importance of trees, which provide a thermal refuge for beetles, should be dispersed within matrixes of open pasture areas and within proximity to adjacent closed‐canopy hammocks to facilitate the exchange of dung beetles between habitats and therefore maintain the provisioning of dung degradation services by dung beetle assemblages.

Prevalence of Bovine Fasciolosis and its Financial Loss at Gulliso Slaughter House, West Wallaga Zone Western Ethiopia

A cross-sectional study conducted in Guliso, from September 2021 to June 2022 sought to identify the kind and prevalence of common Fasciola species in cattle as well as the financial damage resulting from liver condemnation. The study's foundation was a post-mortem examination of the livers of animals that had been killed at the abattoir in the Guliso municipality and its environs. 384 study animals were chosen for post-mortem examination using random systematic sampling procedures in this investigation. In the study, 128 (33.3%) cows had bovine fasciolosis overall. 54 animals (14.1%) had Fasciola gigantica, 49 animals (12.3%) had Fasciola hepatica, and 25 animals (6.5%) had mixed infections. Within the various body condition ratings, there was a significant difference (P&lt;0.05) in the prevalence of bovine fasciolosis. Animals with poor and medium body condition ratings had the highest prevalence (96%) and lowest prevalence (84.7%), respectively, whereas animals with good body condition scores had the lowest prevalence (9.73%). Regarding age, sex, and animal origin, there was no statistically significant difference (P&gt;0.05) in the prevalence of bovine fasciolosis. The estimated yearly financial loss at the abattoir resulting from liver condemnation linked to liver flukes was 138,528 Ethiopian birr. Given the current findings, fasciolosis may be viewed as a serious issue in the area and its environs since the ecological parameters and management circumstances support the survival of both the parasite and its intermediate host, the snail. To prevent pasture contamination and lower the worm burden from affected animals, strategic treatments must be applied at the right time. To maximize the long-term returns from such endemic locations, integrated control techniques involving livestock owners must be developed to reduce the population and activity of snail intermediate hosts.

Investigating parasite dynamics of migratory ungulates for sustaining healthy populations: Application to critically-endangered saiga antelopes Saiga tatarica

Contact between wild and domestic ungulates is increasing across rangelands, enabling disease co-transmission. Disease management is difficult given uncertainties in complex system behavior, limited empirical data, and logistical obstacles to interventions. We studied gastrointestinal nematode (GIN) transmission in a rangeland shared by both livestock and the critically-endangered migratory saiga antelope, Saiga tatarica, in order to model infection dynamics under current and plausible future scenarios of increasing livestock numbers, climate change and anti-helminth treatments. Our model was parameterised for trichostrongylid GIN – a cause of mortality and morbidity in ungulates globally - using data on observed faecal nematode egg output and host numbers and distribution. Results showed that seasonal saiga migration leads to asymmetry in parasite transmission, with the majority of GIN acquired by saigas in their autumn and winter range through prior pasture contamination from livestock. Consequently, reducing parasite burdens in livestock early in the season in these areas could disproportionately reduce cross-transmission to saigas. Early-season GIN suppression in livestock in the saiga's spring and summer range was predicted to have weaker effect on parasite transmission to saigas but reduces infections during the calving period, potentially increasing population health and resilience at this critical time. Optimally timed treatments could offset the effects of increasing livestock numbers on GIN infection pressure, while climate warming had only marginal impacts on GIN transmission under all scenarios. Our findings could support better understanding and mitigation of factors affecting saiga health and rural livelihoods. Our approach is transferable to other systems, particularly those with migratory hosts.

Seasonal output of gastrointestinal nematode eggs and lungworm larvae in farmed wapiti and red deer of New Zealand

Gastrointestinal nematode parasites and lungworm are significant animal health issues for farmed wapiti and red deer (Cervus elaphus). Chronic infection with gastrointestinal nematodes, coupled with sporadic, often pathogenic, outbreaks of the lungworm Dictyocaulus eckerti in young deer has resulted in many farmers relying heavily on anthelmintic treatments. An improved understanding of the epidemiology of the parasites infecting farmed deer, including the sources and seasonality of pasture contamination on the farm, is essential to the development of more integrated and sustainable control programs.The numbers of strongyle nematode eggs and lungworm larvae shed by different stock classes (red and/ or wapiti mixed-age stags, mixed-age red hinds, rising 2-year-old red stags and mix-sex rising 1-year olds) were monitored monthly, across six farms located in different regions of New Zealand, from January 2018 to early 2020. Every month, 10 fresh on-pasture faecal samples were collected from each stock class and couriered overnight to the laboratory. Baermann apparatus to recover lungworm 1st-stage larvae were set up immediately on sample arrival. Faecal samples for nematode faecal egg count were stored at 4 °C until the number of strongyle eggs were counted by mini-FLOTAC. Additional information, including stocking density, grazing systems, and anthelmintic treatments, were also noted every collection month.Results indicate a relatively consistent proportion of animals within each stock class shedding low numbers of both gastrointestinal nematode eggs (about 75 %) and lungworm larvae (about 50 %) all year round. There was little apparent seasonality and few differences between farms (location). Further, the average number of eggs/larvae shed was also relatively constant across seasons and locations, within each stock class. Interestingly, there was little correlation between lungworm larval counts and egg counts suggesting that the same animals were not consistently shedding both parasites.The data indicate that in the presence of regular anthelmintic treatments to young deer (< 1 year old), the adult stock groups constitute a potentially significant source of pasture contamination, and hence future infection. However, these data do not incorporate the seasonal effects of weather on egg/larval development, nor the number of animals of each stock class on the farms. Incorporation of these variables will be necessary to identify the sources and timing of subsequent infection. This work is currently underway.

Study of the Dynamics of Distribution, Seasonality, and Degree of Infection with Bovine Theileriosis in the Territory of Turkestan Region

The relevance of the study is conditioned by the need for rational planning and timely implementation of therapeutic and preventive measures with cattle in various geographical regions, to prevent the spread of ticks and to form an objective understanding of the real features of the epizootic situation in these regions. The purpose of the study is to investigate the dynamics of the spread, the seasonality, and the degree of infection with bovine theileriosis in the Turkestan Region of the Republic of Kazakhstan. The leading approach is a combination of the method of determining the species composition of ixodic mites using the technique developed by V.I. Pomerantsev, with a practical investigation of the seasonality of the spread of ticks, through a survey of various pastures, and regular collection of ticks from cattle during a certain period of the pasture season in stationary points, to establish the species composition of ticks and the degree of contamination of pastures. The research was carried out using the capabilities of the laboratory of the Department of Veterinary Medicine of the regional veterinary laboratory and on the farms of the Turkestan Region. Practical results were obtained in the course of this study, indicating the main trends in the dynamics of the spread, seasonality, and degree of infection with bovine theileriosis in the territory of the Turkestan Region and the country as a whole. The study results and the conclusions formulated on their basis have significant practical significance for livestock workers of the Turkestan Region of Kazakhstan, whose professional duties include monitoring the condition of cattle on these farms and preventing the occurrence and spread of various epidemics among animals.

Sanitary and Hygienic Expertise of Seasonal Contamination of Pastures in the region North Caucasus with Invasive Elements of Nematodes of the Genus Nematodirus Ransom, 1907

Sanitary and Hygienic Expertise of Seasonal Contamination of Pastures in the region North Caucasus with Invasive Elements of Nematodes of the Genus Nematodirus Ransom, 1907