Biomarkers of gastrointestinal nematodes in beef cattle raised in a tropical area.

Biomarkers are specific molecular, histological, or physiological characteristics of normal or pathogenic biological processes and are promising in the diagnosis of gastrointestinal nematodes (GINs). Although some biomarkers have been validated for infection by Ostertagia sp. in cattle raised in temperate regions, there is a lack of information for tropical regions. The aim of this project was to assess potential biomarkers and validate the most promising. In the first study, 36 bovines (Nelore breed) naturally infected by GINs were distributed into two groups: infected (not treated with anthelmintic) and treated (treated with fenbendazole on days 0, 7, 14, 21, 28, 42, and 56). The variables of interest were live weight, fecal egg count, hemogram, serum biochemical markers, phosphorus, gastrin, and pepsinogen. In the second step, pepsinogen was assessed in cattle of the Nelore breed distributed among three groups: infected (not treated with anthelmintic), MOX (treated with moxidectin), and IVM + BZD (treated with ivermectin + albendazole). In the first study, no difference between groups was found for weight, albumin, hematocrit (corpuscular volume [CV]), erythrocytes, or hemoglobin. Negative correlations were found between pepsinogen and both CV and albumin, and albumin was negatively correlated with the percentage of Haemonchus sp. in the fecal culture. Among the biomarkers, only pepsinogen differentiated treated and infected (beginning with the 28th day of the study). In the second study, a reduction in pepsinogen was found after anthelmintic treatment. Therefore, pepsinogen is a promising biomarker of worms in cattle naturally infected by the genera Haemonchus and Cooperia in tropical areas.

Toltrazuril + fenbendazole for cattle: Pharmacokinetics and efficacy against Eimeria spp. and gastrointestinal nematodes.

The present work evaluated the pharmacokinetics and efficacy of the association of 15cmg/kg toltrazuril +5cmg/kg fenbendazole against Eimeria spp. and gastrointestinal nematodes (GINs) in calves of different regions of Brazil (Center-West, Southeast, and South). A total of seven experiments were carried out, five of which determined formulation efficacy against Eimeria spp., considering the following aspects: therapeutic, preventive, metaphylactic, and residual efficacy. Therapeutic efficacy experiments for GINs were carried out by parasitological necropsy. The toltrazuril + fenbendazole association demonstrated ≥95% efficacy against Eimeria spp. for 21 days post-treatment (DPT). When used preventively and metaphylatically, the same association demonstrated ≥97% efficacy against E. zuernii, E. ellipsoidalis, E. cylindrica, E. bovis, E. wyomingensis and E. auburnensis. Toltrazuril + fenbendazole administered seven days before challenge was 100% effective against all these Eimeria species. Results of therapeutic, preventive, metaphylactic and residual efficacies can be related to the pharmacokinetic results, especially considering toltrazuril sulfone, which was detected in animal plasma for a longer period than the parent compound. Toltrazuril + fenbendazole achieved 100% anthelminthic efficacy against the GINs Haemonchus placei (L4), Cooperia pectinata and Oesophagostomum radiatum; 99.94% against adult H. placei; and 99.98% against C. puntacta. The association of toltrazuril + fenbendazole, associated with other measures, is an important and suitable tool for the control and treatment of Eimeria spp. and GINs in young cattle.

Benzimidazole Resistance in Cattle: The First Report of the Presence of F200Y Mutation in Cooperia in Ecuador.

Anthelmintic resistance among GINs in cattle is a worldwide issue. Identifying the early signs of anthelmintic resistance (AR) is necessary to sustainably manage bovine parasitic infections. This study aimed to evaluate the resistance status of bovine parasitic nematodes against FBZ on a farm with a known history of broad-spectrum anthelmintic usage in Ecuador. FBZ efficacy was analyzed using a fecal egg count reduction test (FECR test) and ß-tubulin 1 mutation identification in Cooperia spp., the dominant nematode parasite identified before and after treatment. According to the FECR test, the nematode population was susceptible to FBZ. After amplifying and cloning the ß-tubulin 1 of Cooperia spp., an F200Y mutation was found in 43% of the pooled larva coproculture after treatment. This study reports, for the first time, the presence of F200Y resistance-conferring mutation in Cooperia spp. in Ecuador. Although the nematode population was phenotypically susceptible to FBZ, the presence of F200Y suggests the existence of resistance in the early stages. Our findings highlight the need to implement alternative control strategies for parasitic infections besides broad-spectrum anthelmintics.

Prevalence of trichostrongylus in sheep in the district Zhob, Balochistan, Pakistan / [Prevalência de trichostrongylus em ovelhas no distrito Zhob, Balochistão, Paquistão]

Trichostrongylid em ovelhas foi estudado no Distrito Zhob, Balochistan. Foram coletados 120 tratos gastrointestinais (GIT) de ovelhas do matadouro do distrito. Estas amostras foram processadas para isolamento e identificação de nematódeos tricostrônquicos no Laboratório do Hospital Veterinário do Distrito Zhob. A taxa de prevalência geral foi de 39,1% em machos e 60,8% em fêmeas (p=0,001). A taxa de prevalência em duas raças viz Balochi e Rakhshani foi de 58,3% e 41,6%, respectivamente (p=0,01). A prevalência da espécie observada com Trichostrongylus foi 19,1%, Haemonchus foi 20,8%, Cooperia foi 29,1% e Nematodirus foi 30,8% (p=0,087). Quanto a quantidade de espécies infestadas pelas ovelhas, um único tipo de parasita estava em 32,5% de animais, dois tipos de espécies parasitárias em 36,3% dos animais e três tipos de espécies parasitárias em 30,8% dos animais (p=0,366).(AU)

Primer registro de Cooperia curticei (Strongylida: Trichostrongylidae) en un ovino de la región del noroeste argentino / First report of Cooperia curticei (Strongylida: Trichostrongylidae) in sheep from northwestern Argentina

Resumen Cooperia curticei, es un nematodo afín a los ovinos que se aloja en el intestino delgado de estos. Su presencia en Argentina ha sido registrada en ambientes como la región semiárida en la Pampa, subhúmeda pampeana en Buenos Aires y en la región subtropical en Corrientes. El objetivo de este trabajo es notificar la presencia de Cooperia curticei en intestino delgado de un ovino proveniente de la localidad de Cerrillos en Salta. En el intestino delgado se determinó una carga de 600 formas adultas de Cooperia spp.Estas fueron identificadas como Cooperia curticei. Como características taxonómicas de relevancia las ramas del rayo dorsal se curvaban hacia atrás mostrando una forma de lira. En cuanto a las espículas, midieron en promedio 146,8 µm (± 5,24), con una concavidad marcada en parte media del cuerpo y con un tallo con una curvatura final similar a un pie. Este hallazgo constituye el primero en su tipo en la región del NOA y demuestra la adaptación de C. curticei a un clima de tipo serrano sub-andino. Este trabajo complementa lo descripto previamente en la región, en donde se menciona la presencia de Cooperia spp en ovinos, sin especificar su especie.

Abstract Cooperia curticei is a nematode related to sheep that is housed in the small intestine. Its presence in Argentina has been reported in environments such as the semi-arid region in the Pampa, the sub-humid Pampas in Buenos Aires and in the subtropical region in Corrientes. The objective of this work is to report the presence of Cooperia curticei in the small intestine of a sheep from the town of Cerrillos in Salta. A worm burden of 600 adult forms of Cooperia spp. was determined in the small intestine. These were identified as Cooperia curticei. As relevant taxonomic features the branches of the dorsal ray curved backwards showing a lyre shape. As for the spicules, they measured an average of 146.8 µm (± 5.24), with a marked concavity in the middle part of the body and with a stem with a final curvature similar to a foot. This finding is the first of its kind in the NOA region and demonstrates the adaptation of C. curticei to a sub-Andean mountain type climate. This work complement that previously described in the region, where the presence of Cooperia spp. in sheep was described but without species determination.

Impact on beef cattle productivity of infection with anthelmintic-resistant nematodes.

ABSTRACTAims: The main goal of the current study was to evaluate, on a commercial beef cattle farm, the impact of infection with gastrointestinal nematodes resistant to both ivermectin (IVM) and moxidectin (MXD) on the productivity of calves.Methods: Male Aberdeen Angus calves, aged 9-11 months, with faecal nematode egg counts (FEC) ≥200 epg and body weight ≥190 kg, were allocated to two herds. Herd A (n = 90) grazed a maize-winter forage crop rotation and Herd B (n = 90) grazed a 2-year-old Agropyrum pasture. On Day 0 in each herd, calves were randomly allocated into five groups (n = 18), which were treated with 0.2 mg/kg IVM; 0.2 mg/kg MXD; 3.75 mg/kg ricobendazole (RBZ), both IVM and RBZ, or remained untreated. Faecal samples collected on Days -1 and 19 were used to determine the percentage reduction in FEC, and genera of the nematodes were determined by the identification of the third-stage larvae recovered from faecal cultures. Total weight gain was determined from body weights recorded on Days -1 and 91.Results: Overall mean reduction in FEC was 42% for IVM, 67% for MXD, 97% for RBZ and 99% for IVM + RBZ. The reduction in FEC for Cooperia spp. was ≤78% for IVM and MXD, and for Haemonchus spp. was 0 and 36% for IVM and MXD, respectively, confirming the presence of parasites resistant to both anthelmintics. Only IVM + RBZ treatment resulted in 100% efficacy against Haemonchus spp. The overall estimated mean total weight gain for calves treated with IVM was 15.7 (95% CI = 11.9-19.7) kg and for calves treated with IVM + RBZ was 28.8 (95% CI = 25-32.5) kg (p < 0.001). Mean total weight gain for calves treated with MXD was 23.5 (95% CI = 19.7-27.2) kg.Conclusions and clinical relevance: In calves naturally infected with resistant nematodes, under the production system assessed here, weight gains were lower in calves treated with anthelmintics that were moderately or highly ineffective compared to those treated with highly effective anthelmintics. These results demonstrate to farmers and veterinarians the importance of a sustainable and effective nematode control under field conditions.

Economic analysis of strategic control program (5, 8, 11) for gastrointestinal nematodes in grazing beef cattle during the growing phase in Central Brazil / Análise econômica do programa de controle estratégico (5, 8, 11) de nematodas gastrointestinais em bovinos de corte em recria a pasto no Brasil Central

This study aimed to analyze economically different control protocols for beef cattle gastrointestinal nematodes in Brazil. Field study data previously published was used to compare three groups: 1) non-dosed; 2) current deworming program with two doses - May and November; and 3) alternative strategic control program with three doses - May, August, and November. An economic sensitivity analysis was performed based on beef carcass price (BCP) variation, thus creating three economic scenarios: 1) more probable (M) using the mean BCP in the studied region; 2) optimistic (O) using the mean BCP plus standard deviation; and 3) pessimistic (P) using the mean BCP minus standard deviation. Stock valuation (SV), operational result (OP), and treatment differential (TD) were calculated for each scenario. Average BCP was US$ 2.93 kg-1 carcass (± US$ 0.27 kg-1 carcass). The mean annual cost of deworming per animal was US$ 5.43 and US$ 7.97 for protocols with two and three doses, respectively. The cost of anthelmintic treatment represented 0.63% and 0.74% of operating results, both in M scenario. TD ranged from 9.5% to 27.6% for the assessed protocols. Regardless of the scenario, the protocol with three annual dosages presented the highest SV and OP, which economically justifies its implementation in strategic control of gastrointestinal nematodes in grazing beef cattle in Central Brazil. These results also demonstrate the relevance of strategic anthelmintic treatments in weaned stocker calves in tropical and humid subtropical areas.(AU)

O objetivo deste estudo foi analisar diferentes protocolos de controle de nematodas gastrointestinais em bovinos de corte no Brasil. Dados de estudo de campo publicados anteriormente foram utilizados para comparar três grupos: 1) não dosificado; 2) o programa de desverminação utilizado atualmente com duas dosificações - maio e novembro; e 3) um programa de controle estratégico com três dosificações - maio, agosto e novembro. A análise de sensibilidade econômica foi realizada com base na variação do Preço da Carcaça Bovina (PCB), assim criando três cenários econômicos: mais provável (M), utilizando o PCB médio na região do estudo; Otimista (O), usando o PCB mais o desvio padrão e pessimista (P), usando o PCB menos o desvio padrão. Para cada cenário, a valorização de estoque (VE), o resultado operacional (OP) e o diferencial de tratamento (DT) foram calculados. O PCB médio foi de US$ 2.93 kg-1 de carcaça (± US$ 0.27 kg-1 de carcaça). O custo médio anual de desverminação por animal foi US$ 5.43 e US$ 7.97 no protocolo com duas e três doses, respectivamente, e o custo do anti-helmíntico representou 0.63% e 0.74% do resultado operacional, ambos no cenário M. Os diferenciais de tratamento dos protocolos avaliados variaram de 9.5% a 27.6%. Independentemente do cenário econômico simulado, o protocolo com três dosagens anuais apresentou a maior VE e OP entre os protocolos avaliados, justificando economicamente sua implementação para o controle estratégico de nematodas gastrointestinais de bovinos de corte criados em pastagem no Brasil Central e também demonstram a relevância de tratamentos anti-helmínticos estratégicos em bezerros desmamados em áreas subtropicais tropicais e úmidas.(AU)

Economic analysis of strategic control program (5, 8, 11) for gastrointestinal nematodes in grazing beef cattle during the growing phase in Central Brazil / Análise econômica do programa de controle estratégico (5, 8, 11) de nematodas gastrointestinais em bovinos de corte em recria a pasto no Brasil Central

This study aimed to analyze economically different control protocols for beef cattle gastrointestinal nematodes in Brazil. Field study data previously published was used to compare three groups: 1) non-dosed; 2) current deworming program with two doses - May and November; and 3) alternative strategic control program with three doses - May, August, and November. An economic sensitivity analysis was performed based on beef carcass price (BCP) variation, thus creating three economic scenarios: 1) more probable (M) using the mean BCP in the studied region; 2) optimistic (O) using the mean BCP plus standard deviation; and 3) pessimistic (P) using the mean BCP minus standard deviation. Stock valuation (SV), operational result (OP), and treatment differential (TD) were calculated for each scenario. Average BCP was US$ 2.93 kg-1 carcass (± US$ 0.27 kg-1 carcass). The mean annual cost of deworming per animal was US$ 5.43 and US$ 7.97 for protocols with two and three doses, respectively. The cost of anthelmintic treatment represented 0.63% and 0.74% of operating results, both in M scenario. TD ranged from 9.5% to 27.6% for the assessed protocols. Regardless of the scenario, the protocol with three annual dosages presented the highest SV and OP, which economically justifies its implementation in strategic control of gastrointestinal nematodes in grazing beef cattle in Central Brazil. These results also demonstrate the relevance of strategic anthelmintic treatments in weaned stocker calves in tropical and humid subtropical areas.

O objetivo deste estudo foi analisar diferentes protocolos de controle de nematodas gastrointestinais em bovinos de corte no Brasil. Dados de estudo de campo publicados anteriormente foram utilizados para comparar três grupos: 1) não dosificado; 2) o programa de desverminação utilizado atualmente com duas dosificações - maio e novembro; e 3) um programa de controle estratégico com três dosificações - maio, agosto e novembro. A análise de sensibilidade econômica foi realizada com base na variação do Preço da Carcaça Bovina (PCB), assim criando três cenários econômicos: mais provável (M), utilizando o PCB médio na região do estudo; Otimista (O), usando o PCB mais o desvio padrão e pessimista (P), usando o PCB menos o desvio padrão. Para cada cenário, a valorização de estoque (VE), o resultado operacional (OP) e o diferencial de tratamento (DT) foram calculados. O PCB médio foi de US$ 2.93 kg-1 de carcaça (± US$ 0.27 kg-1 de carcaça). O custo médio anual de desverminação por animal foi US$ 5.43 e US$ 7.97 no protocolo com duas e três doses, respectivamente, e o custo do anti-helmíntico representou 0.63% e 0.74% do resultado operacional, ambos no cenário M. Os diferenciais de tratamento dos protocolos avaliados variaram de 9.5% a 27.6%. Independentemente do cenário econômico simulado, o protocolo com três dosagens anuais apresentou a maior VE e OP entre os protocolos avaliados, justificando economicamente sua implementação para o controle estratégico de nematodas gastrointestinais de bovinos de corte criados em pastagem no Brasil Central e também demonstram a relevância de tratamentos anti-helmínticos estratégicos em bezerros desmamados em áreas subtropicais tropicais e úmidas.

Helminth infections and hybridization between Haemonchus contortus and Haemonchus placei in sheep from Santana do Livramento, Brazil / Infecções helmínticas e hibridização entre Haemonchus contortus e Haemonchus placei em ovinos criados em Santana do Livramento, Brasil

The occurrence and intensity of helminth infections were evaluated in sheep from pastures shared with cattle. In 2015 and 2016, young male sheep acquired in Santana do Livramento, Rio Grande do Sul, Brazil, were finished in integrated crop-livestock system. We selected the 12 sheep that showed the highest number of nematode eggs per gram of faeces to search for worms in the gastrointestinal tract. Haemonchus contortus and Trichostrongylus colubriformis were the major parasites. H. contortus presented mean intensities of 1,159 and 257 worms in 2015 and 2016, respectively. T. colubriformis displayed mean intensities of 4,149 and 2,427 worms in 2015 and 2016, respectively. Of the 127 male specimens of Haemonchus spp. analysed by Polymerase Chain Reaction (PCR), 125 were H. contortus, one Haemonchus placei and one hybrid. Other species detected were Cooperia punctata , Cooperia pectinata, Cooperia spatulata, Cooperia curticei, Ostertagia ostertagi, Teladorsagia circumcincta , Trichostrongylus axei, Nematodirus spathiger , and Trichuris ovis. Twenty lambs presented cysts of Taenia hydatigena in the liver and mesentery. One lamb presented Coenurus cerebralis, the larval stage of Taenia multiceps, in the brain. In conclusion, sheep from pasture shared with cattle presented a high diversity of nematode species. H. contortus and H. placei co-infection occur with consequent hybridization.(AU)

A ocorrência de infecções helmínticas foi avaliada em ovinos que compartilhavam pastagem com bovinos. Em 2015 e em 2016, cordeiros machos foram adquiridos em Santana do Livramento, Rio Grande do Sul, para serem terminados em sistema de lavoura pecuária (ILP). Em cada ano, 12 cordeiros que tinham maior contagem de ovos nas fezes foram abatidos para recuperação dos vermes. Haemonchus contortus e Trichostrongylus colubriformis foram as principais espécies registradas. H. contortus apresentou intensidade média de 1159 e 257 vermes em 2015 e 2016, respectivamente. T. colubriformis apresentou intensidade média de 4149 e 2427 parasitas em 2015 e 2016, respectivamente. De 127 machos de Haemonchus spp. analisados por Polymerase Chain Reaction (PCR), 125 foram identificados como H. contortus, um como Haemonchus placei e um como híbrido. Cooperia punctata, Cooperia pectinata, Cooperia spatulata, Cooperia curticei, Ostertagia ostertagi, Teladorsagia circumcincta , Trichostrongylus axei, Nematodirus spathiger e Trichuris ovis foram as outras espécies de nematódeos registradas. Vinte cordeiros apresentaram cistos de Taenia hydatigena no mesentério e no fígado. Um cordeiro apresentou no cérebro Coenurus cerebralis, o estágio larval de Taenia multiceps . Em conclusão, ovinos criados com bovinos apresentam grande diversidade de nematódeos. A co-infecção de H. contortus e H. placei favorece a produção de híbridos.(AU)

Helminth infections and hybridization between Haemonchus contortus and Haemonchus placei in sheep from Santana do Livramento, Brazil / Infecções helmínticas e hibridização entre Haemonchus contortus e Haemonchus placei em ovinos criados em Santana do Livramento, Brasil

Abstract The occurrence and intensity of helminth infections were evaluated in sheep from pastures shared with cattle. In 2015 and 2016, young male sheep acquired in Santana do Livramento, Rio Grande do Sul, Brazil, were finished in integrated crop-livestock system. We selected the 12 sheep that showed the highest number of nematode eggs per gram of faeces to search for worms in the gastrointestinal tract. Haemonchus contortus and Trichostrongylus colubriformis were the major parasites. H. contortus presented mean intensities of 1,159 and 257 worms in 2015 and 2016, respectively. T. colubriformis displayed mean intensities of 4,149 and 2,427 worms in 2015 and 2016, respectively. Of the 127 male specimens of Haemonchus spp. analysed by Polymerase Chain Reaction (PCR), 125 were H. contortus, one Haemonchus placei and one hybrid. Other species detected were Cooperia punctata , Cooperia pectinata, Cooperia spatulata, Cooperia curticei, Ostertagia ostertagi, Teladorsagia circumcincta , Trichostrongylus axei, Nematodirus spathiger , and Trichuris ovis. Twenty lambs presented cysts of Taenia hydatigena in the liver and mesentery. One lamb presented Coenurus cerebralis, the larval stage of Taenia multiceps, in the brain. In conclusion, sheep from pasture shared with cattle presented a high diversity of nematode species. H. contortus and H. placei co-infection occur with consequent hybridization.

Resumo A ocorrência de infecções helmínticas foi avaliada em ovinos que compartilhavam pastagem com bovinos. Em 2015 e em 2016, cordeiros machos foram adquiridos em Santana do Livramento, Rio Grande do Sul, para serem terminados em sistema de lavoura - pecuária (ILP). Em cada ano, 12 cordeiros que tinham maior contagem de ovos nas fezes foram abatidos para recuperação dos vermes. Haemonchus contortus e Trichostrongylus colubriformis foram as principais espécies registradas. H. contortus apresentou intensidade média de 1159 e 257 vermes em 2015 e 2016, respectivamente. T. colubriformis apresentou intensidade média de 4149 e 2427 parasitas em 2015 e 2016, respectivamente. De 127 machos de Haemonchus spp. analisados por "Polymerase Chain Reaction" (PCR), 125 foram identificados como H. contortus, um como Haemonchus placei e um como híbrido. Cooperia punctata, Cooperia pectinata, Cooperia spatulata, Cooperia curticei, Ostertagia ostertagi, Teladorsagia circumcincta , Trichostrongylus axei, Nematodirus spathiger e Trichuris ovis foram as outras espécies de nematódeos registradas. Vinte cordeiros apresentaram cistos de Taenia hydatigena no mesentério e no fígado. Um cordeiro apresentou no cérebro Coenurus cerebralis, o estágio larval de Taenia multiceps . Em conclusão, ovinos criados com bovinos apresentam grande diversidade de nematódeos. A co-infecção de H. contortus e H. placei favorece a produção de híbridos.

Effect of Gliricidia sepium leaves intake on larval establishment of Cooperia punctata in calves and bio-guided fractionation of bioactive molecules.

The aims of this study were: 1) to assess the anthelmintic effect of Gliricidia sepium on the establishment of C. punctata third-stage larvae (L3) in calves, and 2) to isolate and to elucidate an anti-exsheathment phytochemical from the plant offered during the trial. Twelve ¾ Holstein × Zebu calves were divided in two experimental groups: control (T1) and treatment (T2) (n = 6). After adaptation, each calf was infected with an oral dose of 400 C. punctata L3/Kg LW. Basal diet consisted of Digitaria decumbens hay (6.27% CP) and commercial concentrate (12% CP). In addition, during the experimental period T2 received fresh G. sepium leaves (26.88% CP) ad libitum. On day 9 post-infection, three calves per treatment were randomly selected for slaughter, and worm counts were performed. Larval establishment rates obtained were 13.44 ±â€¯0.13% and 3.1 ±â€¯1.42% for T1 and T2, respectively (P < .05). The reduction of larval establishment was 76.9%. The total length of worms recovered from the animals was also affected by the intake of G. sepium (P < .05). Phytochemicals present in G. sepium leaves offered to calves were isolated through silica gel columns and elucidated through Magnetic Nuclear Resonance (1H and 13C). Bio-guided isolation procedures lead to the elucidation of Oxytroside (Kaempferol 3-O-rhamnopyranosyl-(1 → 6)-ß-D-glucopyranoside-7-O-rhamnopyranoside), which fully inhibited the C. punctata exsheathment process (2400 µg mL-1). Gliricidia sepium represents an alternative to prevent severe C. punctata infections by reducing larval establishment in cattle.

Epidemiologia de helmintos gastrintestinais em búfalos / Epidemiology of gastrointestinal helminths in buffaloes

Este trabalho objetivou avaliar a prevalência e a sazonalidade da infecção natural por parasitos gastrintestinais em bubalinos de aptidão leiteira de diferentes categorias, no município de Bandeirantes, Mato Grosso do Sul. Foram avaliados 41 búfalos da raça Murrah, divididos em três categorias, sendo 11 lactentes, com idade de 0 a 8 meses, 10 desmamados, de 8 a 18 meses, e 20 fêmeas adultas com idade superior a 18 meses. Os animais adultos apresentaram-se livres de parasitismo ou com carga parasitária muito baixa. A categoria lactente apresentou pico de contagem de ovos por grama de fezes (OPG=2038) em novembro, quando a precipitação acumulada foi de 69,3 mm e a temperatura 25,95 °C, enquanto a menor contagem de ovos (167) ocorreu em maio, dois meses após pico de 234,68 mm e 20,59 °C. Os búfalos desmamados apresentaram dois picos de OPG, de 1288 e 875, em setembro e junho, com precipitação de 41,45 e 18,4 mm e temperatura de 24,16 e 20,69 °C, respectivamente. Foi observada correlação significativa (p=0,01) e negativa (r=-0,33) entre o OPG dos bezerros lactentes e precipitação pluviométrica. Os parasitos gastrintestinais mais frequentes foram Haemonchus sp. e Cooperia sp.(AU)

This study evaluated the prevalence and seasonality of natural infection by gastrointestinal parasites and the susceptibility of different dairy buffalo categories in Bandeirantes, state of Mato Grosso do Sul, Brazil. Forty-one Murrah buffaloes were divided into three categories, 11 suckling calves (0-8 months old), 10 weaned calves (8-18 months old), and 20 adult females over the age of 18 months. Adult animals were free from parasitism or showed very low parasite load. The suckling calves showed a peak of egg per gram of feces (EPG = 2038) in November, when the average rainfall was 69.3 mm and the temperature 25.95 °C, while the lowest egg count (167) occurred in May, two months after the peak of 234.68 mm and 20.59 °C. Weaned calves showed two peaks of EPG from 1288.89 and 875 in September and June, with rainfall of 41.45 and 18.4 mm, temperature 24.16 and 20.69 °C, respectively. Significant (p = 0.01) and negative (r = -0.33) correlation between the EPG of suckling calves and precipitation was observed. The most common gastrointestinal parasites were Haemonchus sp. and Cooperia sp.(AU)

Epidemiologia de helmintos gastrintestinais em búfalos / Epidemiology of gastrointestinal helminths in buffaloes

Este trabalho objetivou avaliar a prevalência e a sazonalidade da infecção natural por parasitos gastrintestinais em bubalinos de aptidão leiteira de diferentes categorias, no município de Bandeirantes, Mato Grosso do Sul. Foram avaliados 41 búfalos da raça Murrah, divididos em três categorias, sendo 11 lactentes, com idade de 0 a 8 meses, 10 desmamados, de 8 a 18 meses, e 20 fêmeas adultas com idade superior a 18 meses. Os animais adultos apresentaram-se livres de parasitismo ou com carga parasitária muito baixa. A categoria lactente apresentou pico de contagem de ovos por grama de fezes (OPG=2038) em novembro, quando a precipitação acumulada foi de 69,3 mm e a temperatura 25,95 °C, enquanto a menor contagem de ovos (167) ocorreu em maio, dois meses após pico de 234,68 mm e 20,59 °C. Os búfalos desmamados apresentaram dois picos de OPG, de 1288 e 875, em setembro e junho, com precipitação de 41,45 e 18,4 mm e temperatura de 24,16 e 20,69 °C, respectivamente. Foi observada correlação significativa (p=0,01) e negativa (r=-0,33) entre o OPG dos bezerros lactentes e precipitação pluviométrica. Os parasitos gastrintestinais mais frequentes foram Haemonchus sp. e Cooperia sp.

This study evaluated the prevalence and seasonality of natural infection by gastrointestinal parasites and the susceptibility of different dairy buffalo categories in Bandeirantes, state of Mato Grosso do Sul, Brazil. Forty-one Murrah buffaloes were divided into three categories, 11 suckling calves (0-8 months old), 10 weaned calves (8-18 months old), and 20 adult females over the age of 18 months. Adult animals were free from parasitism or showed very low parasite load. The suckling calves showed a peak of egg per gram of feces (EPG = 2038) in November, when the average rainfall was 69.3 mm and the temperature 25.95 °C, while the lowest egg count (167) occurred in May, two months after the peak of 234.68 mm and 20.59 °C. Weaned calves showed two peaks of EPG from 1288.89 and 875 in September and June, with rainfall of 41.45 and 18.4 mm, temperature 24.16 and 20.69 °C, respectively. Significant (p = 0.01) and negative (r = -0.33) correlation between the EPG of suckling calves and precipitation was observed. The most common gastrointestinal parasites were Haemonchus sp. and Cooperia sp.

EPIDEMIOLOGIA DE HELMINTOS GASTRINTESTINAIS EM BÚFALOS

Abstract This study evaluated the prevalence and seasonality of natural infection by gastrointestinal parasites and the susceptibility of different dairy buffalo categories in Bandeirantes, state of Mato Grosso do Sul, Brazil. Forty-one Murrah buffaloes were divided into three categories, 11 suckling calves (0-8 months old), 10 weaned calves (8-18 months old), and 20 adult females over the age of 18 months. Adult animals were free from parasitism or showed very low parasite load. The suckling calves showed a peak of egg per gram of feces (EPG = 2038) in November, when the average rainfall was 69.3 mm and the temperature 25.95 ºC, while the lowest egg count (167) occurred in May, two months after the peak of 234.68 mm and 20.59 ºC. Weaned calves showed two peaks of EPG from 1288.89 and 875 in September and June, with rainfall of 41.45 and 18.4 mm, temperature 24.16 and 20.69 ºC, respectively. Significant (p = 0.01) and negative (r = -0.33) correlation between the EPG of suckling calves and precipitation was observed. The most common gastrointestinal parasites were Haemonchus sp. and Cooperia sp.

Resumo Este trabalho objetivou avaliar a prevalência e a sazonalidade da infecção natural por parasitos gastrintestinais em bubalinos de aptidão leiteira de diferentes categorias, no município de Bandeirantes, Mato Grosso do Sul. Foram avaliados 41 búfalos da raça Murrah, divididos em três categorias, sendo 11 lactentes, com idade de 0 a 8 meses, 10 desmamados, de 8 a 18 meses, e 20 fêmeas adultas com idade superior a 18 meses. Os animais adultos apresentaram-se livres de parasitismo ou com carga parasitária muito baixa. A categoria lactente apresentou pico de contagem de ovos por grama de fezes (OPG=2038) em novembro, quando a precipitação acumulada foi de 69,3 mm e a temperatura 25,95 ºC, enquanto a menor contagem de ovos (167) ocorreu em maio, dois meses após pico de 234,68 mm e 20,59 ºC. Os búfalos desmamados apresentaram dois picos de OPG, de 1288 e 875, em setembro e junho, com precipitação de 41,45 e 18,4 mm e temperatura de 24,16 e 20,69 ºC, respectivamente. Foi observada correlação significativa (p=0,01) e negativa (r=-0,33) entre o OPG dos bezerros lactentes e precipitação pluviométrica. Os parasitos gastrintestinais mais frequentes foram Haemonchus sp. e Cooperia sp.

The use of nemabiome metabarcoding to explore gastro-intestinal nematode species diversity and anthelmintic treatment effectiveness in beef calves.

Next-generation deep amplicon sequencing, or metabarcoding, has revolutionized the study of microbial communities in humans, animals and the environment. However, such approaches have yet to be applied to parasitic helminth communities. We recently described the first example of such a method - nemabiome sequencing - based on deep-amplicon sequencing of internal transcribed spacer 2 (ITS-2) rDNA, and validated its ability to quantitatively assess the species composition of cattle gastro-intestinal nematode (GIN) communities. Here, we present the first application of this approach to explore GIN species diversity and the impact of anthelmintic drug treatments. First, we investigated GIN species diversity in cow-calf beef cattle herds in several different regions, using coproculture derived L3s. A screen of 50 Canadian beef herds revealed parasite species diversity to be low overall. The majority of parasite communities were comprised of just two species; Ostertagia ostertagi and Cooperia oncophora. Cooperia punctata was present at much lower levels overall, but nevertheless comprised a substantive part of the parasite community of several herds in eastern Canada. In contrast, nemabiome sequencing revealed higher GIN species diversity in beef calves sampled from central/south-eastern USA and Sao Paulo State, Brazil. In these regions C. punctata predominated in most herds with Haemonchus placei predominating in a few cases. Ostertagia ostertagi and C. oncophora were relatively minor species in these regions in contrast to the Canadian herds. We also examined the impact of routine macrocyclic lactone pour-on treatments on GIN communities in the Canadian beef herds. Low treatment effectiveness was observed in many cases, and nemabiome sequencing revealed an overall increase in the proportion of Cooperia spp. relative to O. ostertagi post-treatment. This work demonstrates the power of nemabiome metabarcoding to provide a detailed picture of GIN parasite community structure in large sample sets and illustrates its potential use in research, diagnostics and surveillance.

In vitro larvicidal effect of a hydroalcoholic extract from Acacia cochliacantha leaf against ruminant parasitic nematodes.

The aim of this study was to evaluate the in vitro lethal effect of a hydroalcoholic extract (HAE) from Acacia cochliacantha leaf against three gastrointestinal nematodes species (Haemonchus contortus, H. placei and Cooperia punctata) of domestic ruminants. The HAE was assessed using five concentrations: 100, 125, 175, 150 and 200 mg/ml; 0.5% Ivermectin was used as a positive control and distilled water, as negative control. The data were normalized using the square root and analysed with a completely randomized design through ANOVA analysis using the general lineal model (GLM) of the SAS program. The HAE tannin content was determined through spectrophotometry (UV-visible) and the other major phenols, were identified by chromatographic processes. The results showed an in vitro larvicidal activity of the HAE against the three assessed nematode species with all assessed concentrations. A clear HAE increased concentration dependence effect was observed. The highest activity of the HAE was obtained at the highest concentration (close to 100%, P < 0.05). This result was similar to the one obtained with Ivermectin. On the other hand, the chemical analysis of HAE showed the presence of tannins, caffeoyls and coumaroyl derivates and quercetin as the main compounds. The results suggest that the HAE from this plant species possess in vitro anthelmintic properties. The identified compounds in this study would good candidates for further in vivo researches.

Anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, in combination or individually, in sheep worm control / Eficiência anti-helmíntica da doramectina, fenbendazole e nitroxinil, associados ou utilizados individualmente, no controle da verminose ovina

Abstract The anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, used individually or in combination, was determined by the Fecal Egg Count Reduction (FECR) test and cultivation of larvae of anthelminthic-treated sheep grouped as follows: G1 (doramectin), G2 (fenbendazole), G3 (nitroxynil), G4 (doramectin + fenbendazole), G5 (doramectin + nitroxynil), G6 (fenbendazole + nitroxynil), G7 (doramectin + nitroxynil + fenbendazole), G8 (untreated). In addition to individually used doramectin and fenbendazole, the helminths were also resistant to the combination of doramectin + fenbendazole; nitroxynil + fenbendazole; and doramectin + nitroxynil + fenbendazole, with their FECR rates ranging from 62-83%. The helminths showed possible nitroxynil-resistance, but had low resistance when the drug was administered in combination with doramectin. The evaluation of individual helminth species revealed that fenbendazole was fully effective against Cooperia; doramectin (G1), moderately effective against Haemonchus and insufficiently active against Cooperia; nitroxynil, effective against Haemonchus and insufficiently active against Cooperia. It was concluded from the results that herd nematodes are resistant to doramectin, fenbendazole, and nitroxynil, and that the combined use of the drugs not only fails to significantly improve the anthelmintic efficiency against Haemonchus and Cooperia, but is also cost-ineffective.(AU)

Resumo Eficiências da doramectina, fenbendazole e nitroxynil, utilizados individualmente ou associadamente, foram determinadas através do Teste de Redução na Contagem de Ovos nas Fezes (RCOF) e cultivo de larvas. Os grupos experimentais foram os seguintes: G1 (ovinos tratados com doramectina), G2 (fenbendazole), G3 (nitroxynil), G4 (doramectina + fenbendazole), G5 (doramectina + nitroxynil), G6 (fenbendazole + nitroxynil), G7 (doramectina + fenbendazole + nitroxynil) e G8, não tratados. Os helmintos foram considerados resistentes a doramectina e ao fenbendazole isoladamente e às associações doramectina + fenbendazole, fenbendazole + nitroxynil, e doramectina + fenbendazole + nitroxynil, com taxas de RCOF variando de 62-83%. Helmintos foram considerados suspeitos de resistência ao nitroxynil e apresentaram baixa resistência, quando esta droga foi associada à doramectina. Dos tratamentos isolados, o fenbendazole demonstrou total eficácia (100%) contra Cooperia. Doramectina (G1) foi moderadamente efetiva contra Haemonchus e insuficientemente ativa contra Cooperia, e o nitroxynil efetivo contra Haemonchus (93,2%) e insuficientemente ativo contra Cooperia (0%). Concluiu-se neste estudo que os nematódeos do rebanho são resistentes à doramectina, fenbendazole e nitroxynil, e que, ainda que associadas, não devem ser utilizadas no rebanho por não melhorarem a eficiência anti-helmíntica nem a efetividade contra Haemonchus e Cooperia e por não apresentarem custo-benefício justificado.(AU)

Anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, in combination or individually, in sheep worm control / Eficiência anti-helmíntica da doramectina, fenbendazole e nitroxinil, associados ou utilizados individualmente, no controle da verminose ovina

Abstract The anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, used individually or in combination, was determined by the Fecal Egg Count Reduction (FECR) test and cultivation of larvae of anthelminthic-treated sheep grouped as follows: G1 (doramectin), G2 (fenbendazole), G3 (nitroxynil), G4 (doramectin + fenbendazole), G5 (doramectin + nitroxynil), G6 (fenbendazole + nitroxynil), G7 (doramectin + nitroxynil + fenbendazole), G8 (untreated). In addition to individually used doramectin and fenbendazole, the helminths were also resistant to the combination of doramectin + fenbendazole; nitroxynil + fenbendazole; and doramectin + nitroxynil + fenbendazole, with their FECR rates ranging from 62-83%. The helminths showed possible nitroxynil-resistance, but had low resistance when the drug was administered in combination with doramectin. The evaluation of individual helminth species revealed that fenbendazole was fully effective against Cooperia; doramectin (G1), moderately effective against Haemonchus and insufficiently active against Cooperia; nitroxynil, effective against Haemonchus and insufficiently active against Cooperia. It was concluded from the results that herd nematodes are resistant to doramectin, fenbendazole, and nitroxynil, and that the combined use of the drugs not only fails to significantly improve the anthelmintic efficiency against Haemonchus and Cooperia, but is also cost-ineffective.

Resumo Eficiências da doramectina, fenbendazole e nitroxynil, utilizados individualmente ou associadamente, foram determinadas através do Teste de Redução na Contagem de Ovos nas Fezes (RCOF) e cultivo de larvas. Os grupos experimentais foram os seguintes: G1 (ovinos tratados com doramectina), G2 (fenbendazole), G3 (nitroxynil), G4 (doramectina + fenbendazole), G5 (doramectina + nitroxynil), G6 (fenbendazole + nitroxynil), G7 (doramectina + fenbendazole + nitroxynil) e G8, não tratados. Os helmintos foram considerados resistentes a doramectina e ao fenbendazole isoladamente e às associações doramectina + fenbendazole, fenbendazole + nitroxynil, e doramectina + fenbendazole + nitroxynil, com taxas de RCOF variando de 62-83%. Helmintos foram considerados suspeitos de resistência ao nitroxynil e apresentaram baixa resistência, quando esta droga foi associada à doramectina. Dos tratamentos isolados, o fenbendazole demonstrou total eficácia (100%) contra Cooperia. Doramectina (G1) foi moderadamente efetiva contra Haemonchus e insuficientemente ativa contra Cooperia, e o nitroxynil efetivo contra Haemonchus (93,2%) e insuficientemente ativo contra Cooperia (0%). Concluiu-se neste estudo que os nematódeos do rebanho são resistentes à doramectina, fenbendazole e nitroxynil, e que, ainda que associadas, não devem ser utilizadas no rebanho por não melhorarem a eficiência anti-helmíntica nem a efetividade contra Haemonchus e Cooperia e por não apresentarem custo-benefício justificado.

Changes in biochemical analytes in calves infected by nematode parasites in field conditions.

Parasitic infections caused by nematodes are a major problem in bovines that resulting in losses in animal health and production. Thus, the aim of this study was to evaluate alterations in selected serum biochemical analytes in calves naturally infected with gastrointestinal (GI) and pulmonary nematodes without clinical signs. For this, samples of feces and blood of 86 calves were collected. Fecal egg counts (FEC) were determined using the modified McMaster technique with a sensitivity of 50 eggs per gram of feces (EPG). Positive nematode FEC was processed for coproculture using pooled samples to identify Strongylidae infective larvae (L3). First stage-larvae (L1) of Dictyocaulus viviparous were identified by a modified Baermann method. The biochemical analytes determined were: acute phase proteins such as haptoglobin and paraoxonase type 1; the enzymes acetylcholinesterase; butyrylcholinesterase; the lipid profile (triglycerides and total, HDL, and LDL-cholesterol); serum iron profile (iron and unsaturated iron-binding capacity); total protein and albumin; pancreatic profile (amylase and lipase); and minerals (phosphorus and calcium). The calves were divided into four groups according to the results of EPG and the modified Baermann method. Group 1: healthy control animals (n=16); Group 2: calves with only GI parasites (n=51): This group was sub-divided into sub-groups according to the EPG threshold: 2a-GI parasites with low EPG (n=23), and 2b-GI parasites with high EPG (n=28). Group 3: animals with only lungworms (n=5), and Group 4: calves with lung+GI parasites (n=14). The more prevalent genera in all coprocultures were: Cooperia spp., Haemonchus spp., Oesophagostomum spp., and Trichostrongylus spp. The nonparametric Kruskal-Wallis test was used to compare the groups and Dunn's post-test was used for multiple comparisons as the data was not normally distributed (P<0.05). The haptoglobin concentration increased in calves with GI and pulmonary parasites. A significant increase in acetylcholinesterase was observed in calves infected with lungworms. Cholesterol, triglycerides, HDL, and LDL concentrations decreased but lipase concentration increased in calves with GI parasites. Therefore, this paper provides an overview of the biochemical effects produced by nematode parasites in calves in field conditions. These findings in calves without any evident clinical signs of disease could provide an indication of GI parasites and lungworm infection, especially in an endemic area for these parasites.

Actividad ovicida de extractos de cuatro especies de plantas contra el nematodo gastrointestinal Cooperia punctata / Ovicide activity of extracts of four plant species against the gastrointestinal nematode Cooperia punctata

El uso de plantas bioactivas representa una alternativa para el control de Cooperia punctata en el ganado de pastoreo. Los objetivos de este estudio fueron: (1) evaluar la actividad ovicida de extractos de cuatro especies de plantas contra C. punctata, (2) determinar la participación de los compuestos polifenólicos (cp) en la actividad antihelmíntica (ah) y (3) evaluar el mejor método de extracción para alcanzar una actividad ovicida. El bioensayo de inhibición de la eclosión de huevos (ieh) fue utilizado para evaluar el efecto ovicida de Leucaena leucocephala, Gliricidia sepium, Guazuma ulmifolia y Cratylia argentea; con diferentes métodos de extracción: acuoso (aq), acetona: agua (aw) y acetónico (ac). Los huevos de C. punctata fueron incubados por cuadruplicado a 0.6, 1.2, 2.4, 4.8 y 9.6 mg mL-1 de cada uno de los extractos de plantas. La participación de los cp fue determinada mediante el uso de polietilenglicol (peg). Los 12 extractos de plantas inhibieron la eclosión de huevos de modo dosis-dependiente, y las mejores concentraciones letales medias (CL50) fueron: 1.03 ± 0.17 para G. sepium-ac, y 7.90 ± 1.19 mg mL-1 para L. leucocephala-aq. Se observaron diferencias en la actividad ah según el método de extracción (P < 0.05). A mayor concentración, L. leucocephala-aq inhibió más del 50 % de la eclosión de C. punctata, entretanto, el extracto G. sepium-ac inhibió la eclosión en su totalidad. La adición de peg demostró la participación de los cp en la actividad ah de la mayoría de los extractos; no obstante, con G. sepium-ac, los cp no fueron los principales compuestos bioactivos. En general, el mejor método de extracción fue acetona:agua, pues permitió obtener una buena actividad ovicida, con un mayor rendimiento del extracto. Las tasas de inhibición sugieren que L. leucocephala y G. sepium podrían ser evaluadas con la finalidad de reducir la densidad larvaria en pastos.