Evaluation of different supportive treatments during packed cell volume replacement in calves naturally infected with tick fever agents.

This study evaluated the effect of different supportive treatments on PCV replacement of dairy calves naturally infected with tick fever (TF) agents, and treated with diminazene and enrofloxacin. Five products were tested as supportive treatments in four experiments. In these experiments, we used Girolando female calves (Gyr × Holstein, genetic ratio of 15/16 and 31/32 Holstein) four to six months old, raised in pasture, naturally infected with TF agents, and infested with R. microplus. Supportive treatment was administered once on day 0 of the study concurrently with specific treatment targeting TF agents. The animals were observed on days 0, 3, and 7. Oral or intravenous administration of a vitamin complex and mineral salts enhanced the increase in PCV and biochemical analytes present in the serum of calves naturally infected with TF agents. No positive effect on PCV values was observed with the administration of (1) invigorating tonic: calcium, casein-peptides and vitamin B12, (2) iron-based stimulant tonic and (3) metabolic tonic: vitamin A, vitamin D, and a fraction of polyunsaturated fatty acids. Supplementation by injection with Type III iron resulted in increased hemoglobin and PCV in treated animals. However, these results did not occur with iron citrate. Therefore, more studies with Type III iron need to be performed. Supportive treatment conferred no advantage in animals with no history of reduced PCV.

Traditional practices of the ethnoveterinary plants in the Kaghan Valley, Western Himalayas-Pakistan / Prácticas tradicionales etnoveterinarias de las plantas en el valle de Kaghan, Himalaya occidental Pakistán

Introduction: Indigenous people in a far-flung mountainous area without basic facilities, mainly rely on medicinal plants to cope with various veterinary health problems. Objective: The present study was carried out to explore the traditional knowledge of ethnoveterinary practices in Kaghan Valley, district Mansehra, Western Himalayas-Pakistan. Method: Ethnoveterinary data were collected between February to October 2014 from nine villages of the Kaghan Valley by involving 80 local people include traditional healers using a semi-structured interview. Results: A sum of 41 plant taxa of ethnoveterinary medicinal plants was documented for treating livestock ailments. Out of which, herbaceous plants were recorded with high percentage (27 species, 65.8 %). Most of the species were used to treat gastrointestinal diseases (12 taxa), followed by health improvement (7 taxa). The widely used part of plants for livestock aliments was the whole plant (9 species) followed by leaves (7 species), and preparation were paste (18 species) followed by powder with 10 species. The highest used values were recorded for Arisaema costatum (0.82), Primula denticulata (0.76), and high relative frequency citations for Berberis lyceum and Dryopteris ramosa with 0.37 each. Among the plant species Skimmia laureola, Thymus linearis and Phytolacca latbenia were among the taxa with cent fidelity level. Conclusion: The flora used in traditional remedies of the valley was found mostly endemic due to excessive utilization. Thus, further chemical investigation, better utilization and conservation of indigenous use of the reported species should be considered for future work.

Introducción: Los pueblos indígenas de zonas montañosas lejanas sin facilidades básicas dependen principalmente de las plantas medicinales para afrontar problemas de salud de tipo veterinario. Objetivo: Explorar el conocimiento tradicional en las prácticas etnoveterinarias en el valle de Kaghan, distrito de Mansehra, Himalaya occidental-Pakistán. Métodos: Se recopilaron datos etnoveterinarios mediante una entrevista semiestructurada entre febrero y octubre de 2014 en nueve aldeas del valle de Kaghan, con la participación de 80 habitantes locales, incluidos curanderos tradicionales. Resultados: Se documentó un total de 41 taxones de plantas medicinales etnoveterinarias para el tratamiento de enfermedades del ganado. Se registró un alto porcentaje de plantas herbáceas (27 especies, 65.8 %). La mayoría de las especies utilizadas han sido para tratar enfermedades gastrointestinales (12 taxones), y mejora de la salud (7 taxones). Para el tratamiento de enfermedades del ganado, lo más usual fue utilizar la planta entera (9 especies), seguida de las hojas (7 especies), con preparación en pasta (18 especies) y en polvo (10 especies). Las especies registradas con más uso fueron: Arisaema costatum (0.82), Primula denticulata (0.76) y Berberis lyceum y Dryopteris ramosa con la misma alta frecuencia relativa (0.37 cada una). Las especies Skimmia laureola, Thymus linearis y Phytolacca latbenia se reportaron entre los taxones con mayor nivel de fidelidad porcentual. Conclusión: La flora utilizada en los remedios tradicionales del valle de Kaghan fue mayoritariamente endémica. Se propone para trabajos futuros mayor investigación química, y mayor utilización y conservación en las especies de plantas reportadas por los indígenas.

Effect of the administration of Lactobacillus spp. strains on neonatal diarrhoea, immune parameters and pathogen abundance in pre-weaned calves.

Neonatal calf diarrhoea is one of the challenges faced by intensive farming, and probiotics are considered a promising approach to improve calves' health. The objective of this study was to evaluate the effect of potential probiotic lactobacilli on new-born dairy calves' growth, diarrhoea incidence, faecal score, cytokine expression in blood cells, immunoglobulin A (IgA) levels in plasma and faeces, and pathogen abundance in faeces. Two in vivo assays were conducted at the same farm in two annual calving seasons. Treated calves received one daily dose of the selected lactobacilli (Lactobacillus reuteri TP1.3B or Lactobacillus johnsonii TP1.6) for 10 consecutive days. A faecal score was recorded daily, average daily gain (ADG) was calculated, and blood and faeces samples were collected. Pathogen abundance was analysed by absolute qPCR in faeces using primers directed at Salmonella enterica, rotavirus, coronavirus, Cryptosporidium parvum and three Escherichia coli virulence genes (eae, clpG and Stx1). The faecal score was positively affected by the administration of both lactobacilli strains, and diarrhoea incidence was significantly lower in treated calves. No differences were found regarding ADG, cytokine expression, IgA levels and pathogen abundance. Our findings showed that oral administration of these strains could improve gastrointestinal health, but results could vary depending on the calving season, which may be related to pathogen seasonality and other environmental effects.

Palicourea marcgravii (Rubiaceae) poisoning in cattle grazing in Brazil.

Palicourea marcgravii is the most important poisonous plant of cattle in Brazil. It contains monofluoroacetic acid and causes sudden death associated with exercise. Herein, we describe the temporal and spatial distribution of the toxic disease. The survey was based on the epidemiological, clinical, and pathological data of the Setor de Anatomia Patológica (SAP) of the Universidade Federal Rural do Rio de Janeiro (UFRuralRJ) to report outbreaks of poisoning by P. marcgravii, from 1953 to 2018. Clinical signs were peracute and included labored breathing, loss of balance, muscle tremors, lateral recumbency, and limb paddling. Gross lesions such as congestion of large vessels and edema and pulmonary congestion were observed. Multifocal areas of vacuolar hydropic degeneration of distal contorted tubule cells with nuclear pyknosis were observed in the kidneys. The plant is found in forests, and the poisoning occurs mainly after clearing forests for pasture, in areas of natural forest recovery called "capoeira," which provide a favorable environment for maintaining P. marcgravii growth. Outbreaks of P. marcgravii poisoning coincided with periods of creation of large deforested pastures in the Southeast and Midwest regions of Brazil, and the poisoning should be considered an additional risk after deforestation. The most effective prophylaxis is fencing off the forest areas that contain these plants.

A new passive immune strategy based on IgY antibodies as a key element to control neonatal calf diarrhea in dairy farms.

BACKGROUND: Neonatal diarrhea remains one of the main causes of morbi-mortality in dairy calves under artificial rearing. It is often caused by infectious agents of viral, bacterial, or parasitic origin. Cows vaccination and colostrum intake by calves during the first 6 h of life are critical strategies to prevent severe diarrhea but these are still insufficient. Here we report the field evaluation of a product based on IgY antibodies against group A rotavirus (RVA), coronavirus (CoV), enterotoxigenic Escherichia coli, and Salmonella sp. This product, named IgY DNT, has been designed as a complementary passive immunization strategy to prevent neonatal calf diarrhea. The quality of the product depends on the titers of specific IgY antibodies to each antigen evaluated by ELISA. In the case of the viral antigens, ELISA antibody (Ab) titers are correlated with protection against infection in calves experimentally challenged with RVA and CoV (Bok M, et al., Passive immunity to control bovine coronavirus diarrhea in a dairy herd in Argentina, 2017), (Vega C, et al., Vet Immunol Immunopathol, 142:156-69, 2011), (Vega C, et al., Res Vet Sci, 103:1-10, 2015). To evaluate the efficiency in dairy farms, thirty newborn Holstein calves were randomly assigned to IgY DNT or control groups and treatment initiated after colostrum intake and gut closure. Calves in the IgY DNT group received 20 g of the oral passive treatment in 2 L of milk twice a day during the first 2 weeks of life. Animals were followed until 3 weeks of age and diarrhea due to natural exposure to infectious agents was recorded during all the experimental time. RESULTS: Results demonstrate that the oral administration of IgY DNT during the first 2 weeks of life to newborn calves caused a delay in diarrhea onset and significantly reduced its severity and duration compared with untreated calves. Animals treated with IgY DNT showed a trend towards a delay in RVA infection with significantly shorter duration and virus shedding compared to control calves. CONCLUSIONS: This indicates that IgY DNT is an effective product to complement current preventive strategies against neonatal calf diarrhea in dairy farms. Furthermore, to our knowledge, this is the only biological product available for the prevention of virus-associated neonatal calf diarrhea.

Intrauterine therapy with ozone reduces subclinical endometritis and improves reproductive performance in postpartum dairy cows managed in pasture-based systems.

New postpartum strategies have been developed in dairy cows to ameliorate uterine health and reproductive performance, especially the first service conception rates. This study aimed to assess the effect of intrauterine therapy with ozone (IUTO) in early postpartum on subclinical endometritis prevalence and reproductive parameters in dairy cows under commercial farm conditions. For this purpose, eighty clinically healthy cows with a body condition score between 3.0 and 3.5, from four dairy farms, were randomly allocated into two groups: ozone therapy group (OG, n = 40), which were subjected to IUTO, and control group (CG, n = 40). Content of uterine polymorphonuclear (PMN) leukocytes and subclinical endometritis (SE) percentage were assessed at 35 days after calving by uterine cytology. A second cytology was performed 72 h after IUTO. Reproductive parameters such as interval calving to first service (IFS), number of services per conception (nSC), interval calving to conception (ICC) and first service conception rate (FSCR) were analysed. The second endometrial cytology demonstrated that IUTO reduced (P < 0.01) both PMN (3.7 ± 1.4 vs. 7.6 ± 1.1%) and SE (5.0 vs. 50.0%) percentages compared with CG. Likewise, after ozone treatment, both nSC (2.1 ± 0.3 vs. 3.1 ± 0.2; P < 0.01) and ICC (126.2 ± 9.7 vs. 149.0 ± 9.0; P = 0.0672) decreased, and FSCR increased (50.0 vs. 16.2%; P < 0.01) compared with CG. In conclusion, intrauterine ozone therapy applied at 35 days after calving reduced subclinical endometritis prevalence and improved reproductive performance in postpartum dairy cows managed in a pasture-based system.

Efectividad de Beauveria bassiana (Baubassil®) sobre la garrapata común del ganado bovino Rhipicephalus microplus en el Departamento de la Guajira, Colombia / Effectiveness of Beauveria bassiana (Baubassil®) on the common cattle tick Rhipicephalus microplus in the Department of Guajira, Colombia

Se evaluó la efectividad de Baubassil® (Beauveria bassiana) sobre la garrapata Rhipicephalus (Boophilus) microplus. En la fase in vitro, se determinaron la temperatura óptima de germinación del hongo mediante microcultivos a 25, 30 y 35° C, y la mortalidad de las garrapatas. En campo, en un diseño aleatorio, se utilizaron 30 vacas cebuinas; 15 vacas se trataron con Baubassil® una vez por semana con 1 x 10(6) conidias/ml y un grupo control se dejó sin tratamiento. Se observó que a temperaturas de 25, 30 y 35 °C, la germinación del entomopató-geno fue del 97,5, el 94,7 y el 6,3%, respectivamente. En los animales tratados con Baubassil® se obtuvo una efectividad corregida del 96,8%. En el Caribe Seco, Baubassil® constituiría una alternativa de control del ectoparásito, pues no existen registros anteriores en La Guajira del control sostenible de esta garrapata.

The effectiveness of Baubassil® (Beauveria bassiana) on the tick Rhipicephalus (Boophilus) microplus was evaluated. In the in vitro phase, the optimal germination temperature of the fungus was determined by microcultures at 25, 30 and 35 °C and the mortality of ticks. In the field, in a randomized design, 30 cebuine cows; 15 cows were treated with Baubassil® once a week at a 1 x 10(6) conidia/ml, and a control group was left untreated. It was observed that at temperatures of 25, 30 and 35 °C, germination of the entomopathogen was 97.5, 94.7 and 6.3%, respectively. In animals treated with Baubassil® obtained a corrected effectiveness of 96.8% on ticks in the fifth week of application. The use of Baubassil® would be a valid alternative for controlling the cattle tick under the agroecological conditions of the Dry Caribbean.

Lameness on Brazilian pasture based dairies - Part 2: Conversations with farmers and dairy consultants.

A farmer or a dairy consultant's ability to identify and properly treat lame dairy cows is key to managing lameness on farms. However, this ability is dependent on their knowledge and perceptions regarding lameness. To date these topics are poorly understood in all dairy systems. To our knowledge, this is the first study that uses a qualitative approach to describe the perception of lameness in Brazilian pasture-based dairy farms. The aim of this study was firstly, to contextualize farmers and dairy consultants' culture and knowledge on the topic of lameness and, secondly, to understand how these factors may influence lameness management on the farms. In-depth face-to-face semi-structured interviews were done with participating farm owners (n = 21) and dairy consultants (n = 13). Thematic analyses of the interview content provided evidence that the dairy community's overarching culture around lameness acts as a barrier preventing positive actions targeting lameness control and prevention. The emerging themes identified indicate that lameness is a vague, ill-defined concept among both farmers and dairy consultants working in this region. There was a shared belief that pasture-based systems have a low risk for lameness. Furthermore, the prevailing culture for tackling lameness was reactive, particularly in the case of lame cows affected by physical trauma or environmental factors. Treatment was frequently delayed and the misuse of antibiotics was evident. Described community culture was rationalised via the cognitive dissonance and health belief models. We suggest that increased dialogue, including educational efforts within the community, may lead to increased sensitivity of risk perception of lameness within the community and in turn trigger appropriate diagnosis and treatment of lame cows.

Coadministration of Nematophagous Fungi for Biological Control over Nematodes in Bovine in the South-Eastern Brazil.

This study compared the coadministration among the three nematode predatory fungi, Duddingtonia flagrans, Monacrosporium thaumasium, and Arthrobotrys robusta, in the biological control of cattle gastrointestinal nematodiasis in comparison with the use of the fungus D. flagrans alone. Five groups consisting of eight Girolando heifers were kept in paddocks of Brachiaria decumbens for six months. Each heifer received 1 g/10 kg of pellets containing the fungi (0.2 g of fungus/10 kg b.w.). Group 1 (G1) received pellets with D. flagrans and M. thaumasium in coadministration, G2 received D. flagrans and A. robusta, G3 received M. thaumasium, A. robusta, and D. flagrans, and G4 received the fungus D. flagrans alone. Group 5 (control) received pellets without fungi. The monthly mean of fecal egg count (FEC) of Groups 1, 2, 3, and 4 were 93.8, 85.3, 82.7, and 96.4% smaller than the mean of control group. The treatments with pellets containing D. flagrans or D. flagrans + M. thaumasium produced significantly better results than the D. flagrans + A. robusta or the combination of the three fungi. The associations which include A. robusta were less efficient in this study than D. flagrans alone or associated with M. thaumasium.

Probiotic properties of native Lactobacillus spp. strains for dairy calves.

The use of native microorganisms with probiotic capacity is an alternative tool for the treatment and prevention of several diseases that affect animals, such as neonatal calf diarrhoea. The selection of probiotic strains within a collection is based on different in vitro and in vivo assays, which predict their potential. The aim of this study was to characterise a group of native Lactobacillus spp. strains isolated from faeces of healthy calves using an in vitro approach and to assess their ability to colonise the gastrointestinal tract (GIT) of calves. Native Lactobacillus spp. strains were evaluated on their capacity to survive low pH conditions and bile salts presence, biofilm formation and adhesion to both mucus and Caco-2 cells. Based on the in vitro characterisation, four strains (Lactobacillus johnsonii TP1.1, Lactobacillus reuteri TP1.3B, L. johnsonii TP1.6 and Lactobacillus amylovorus TP8.7) were selected to evaluate their capacity to colonise and persist in the GIT of calves. The assessment of enteric persistence involved an in vivo assay with oral administration of probiotics and quantification in faeces of the administered bacterial species with real-time quantitative PCR (qPCR). The study was conducted using 15 calves (1-month-old) which were divided into five groups of three animals, four of which were treated with four different selected strains and one was the control group. Strains TP1.3B and TP1.6 managed to persist in treated animals until ten days after the end of the administration period, indicating that they could be promising candidates for the design of probiotics for calves.

[Effectiveness of Beauveria bassiana (Baubassil®) on the common cattle tick Rhipicephalus microplus in the Department of Guajira, Colombia]. / Efectividad de Beauveria bassiana (Baubassil®) sobre la garrapata común del ganado bovino Rhipicephalus microplus en el Departamento de la Guajira, Colombia.

The effectiveness of Baubassil®(Beauveria bassiana) on the tick Rhipicephalus (Boophilus) microplus was evaluated. In the in vitro phase, the optimal germination temperature of the fungus was determined by microcultures at 25, 30 and 35°C and the mortality of ticks. In the field, in a randomized design, 30 cebuine cows; 15 cows were treated with Baubassil® once a week at a 1×106 conidia/ml, and a control group was left untreated. It was observed that at temperatures of 25, 30 and 35°C, germination of the entomopathogen was 97.5, 94.7 and 6.3%, respectively. In animals treated with Baubassil® obtained a corrected effectiveness of 96.8% on ticks in the fifth week of application. The use of Baubassil® would be a valid alternative for controlling the cattle tick under the agroecological conditions of the Dry Caribbean.

Economic evaluation and efficacy of strategic-selective treatment of gastrointestinal parasites in dairy calves.

In the Experimental Farm of the Universidade Federal de Lavras (EF-UFLA), state of Minas Gerais, Brazil, on their day of birth, female Holstein calves were randomly selected and placed into two groups containing fifteen animals each: Strategic-Selective Treatment (S-ST) or Conventional Treatment (CT). In the S-ST, calves were treated after coproparasitological examinations according to criteria established previously by the researchers. Calves in the CT were treated according to the opinion of the veterinarian of EF-UFLA. For statistical analysis, the frequency (%) of fecal samples with count of eggs per gram of feces (EPG) ≥300, count of oocysts per gram of feces (OoPG) ≥500 and fecal samples with count of cysts of Giardia spp. ≥1 were conducted. The overall average frequency of fecal samples with EPG ≥300, OoPG ≥500 and Giardia spp. cysts ≥1, respectively, was similar (p >0.05) between S-ST (20.3%; 17.3%; and 31.5%) and CT (26.4%; 23.9%; and 37.3%). The effective operational cost, per animal, in 12 months, was of R$ 784.58 (US$ 241.41) and R$ 83.90 (US$ 25.81) in S-ST and CT, respectively. The S-ST requires adjustments to be used as a technically efficient and economically viable alternative for the control of gastrointestinal parasitosis in female Holstein calves.

Defective sperm head decondensation undermines the success of ICSI in the bovine.

The efficiency of intracytoplasmic sperm injection (ICSI) in the bovine is low compared to other species. It is unknown whether defective oocyte activation and/or sperm head decondensation limit the success of this technique in this species. To elucidate where the main obstacle lies, we used homologous and heterologous ICSI and parthenogenetic activation procedures. We also evaluated whether in vitro maturation negatively impacted the early stages of activation after ICSI. Here we showed that injected bovine sperm are resistant to nuclear decondensation by bovine oocytes and this is only partly overcome by exogenous activation. Remarkably, when we used heterologous ICSI, in vivo-matured mouse eggs were capable of mounting calcium oscillations and displaying normal PN formation following injection of bovine sperm, although in vitro-matured mouse oocytes were unable to do so. Together, our data demonstrate that bovine sperm are especially resistant to nuclear decondensation by in vitro-matured oocytes and this deficiency cannot be simply overcome by exogenous activation protocols, even by inducing physiological calcium oscillations. Therefore, the inability of a suboptimal ooplasmic environment to induce sperm head decondensation limits the success of ICSI in the bovine. Studies aimed to improve the cytoplasmic milieu of in vitro-matured oocytes and to replicate the molecular changes associated with in vivo capacitation and acrosome reaction will deepen our understanding of the mechanism of fertilization and improve the success of ICSI in this species.

Economic evaluation and efficacy of strategic-selective treatment of gastrointestinal parasites in dairy calves / Avaliação econômica e eficácia do tratamento estratégico-seletivo de parasitos gastrointestinais em bezerras leiteiras

In the Experimental Farm of the Universidade Federal de Lavras (EF-UFLA), state of Minas Gerais, Brazil, on their day of birth, female Holstein calves were randomly selected and placed into two groups containing fifteen animals each: Strategic-Selective Treatment (S-ST) or Conventional Treatment (CT). In the S-ST, calves were treated after coproparasitological examinations according to criteria established previously by the researchers. Calves in the CT were treated according to the opinion of the veterinarian of EF-UFLA. For statistical analysis, the frequency (%) of fecal samples with count of eggs per gram of feces (EPG) ≥300, count of oocysts per gram of feces (OoPG) ≥500 and fecal samples with count of cysts of Giardia spp. ≥1 were conducted. The overall average frequency of fecal samples with EPG ≥300, OoPG ≥500 and Giardia spp. cysts ≥1, respectively, was similar (p >0.05) between S-ST (20.3%; 17.3%; and 31.5%) and CT (26.4%; 23.9%; and 37.3%). The effective operational cost, per animal, in 12 months, was of R$ 784.58 (US$ 241.41) and R$ 83.90 (US$ 25.81) in S-ST and CT, respectively. The S-ST requires adjustments to be used as a technically efficient and economically viable alternative for the control of gastrointestinal parasitosis in female Holstein calves.(AU)

Na Fazenda Experimental da Universidade Federal de Lavras (FE-UFLA), Minas Gerais, Brasil, no dia do nascimento, bezerras da raça holandesa foram sorteadas de forma aleatória para compor um dos dois grupos, formados por 15 animais cada: Tratamento Estratégico-Seletivo (TE-S) ou Tratamento Convencional (TC). No TE-S, as bezerras foram tratadas após exames coproparasitológicos de acordo com critérios previamente estabelecidos pelos pesquisadores. No TC, as bezerras foram tratadas conforme orientação do veterinário da FE-UFLA. Em ambos grupos, as bezerras foram monitoradas a cada 14 dias, do nascimento até os 12 meses de idade, por meio de exames coproparasitológicos. Para análise estatística, considerou-se a frequência (%) de amostras fecais com contagem de ovos por grama de fezes (OPG) ≥300, contagem de oocistos por grama de fezes (OoPG) ≥500, e amostras fecais com contagem de cistos de Giardia spp. ≥1. A frequência média global de amostras fecais com contagem de OPG ≥300, OoPG ≥500 e cistos de Giardia spp. ≥1, respectivamente, foi similar (p >0,05) entre TE-S (20,3%; 17,3%; e 31,5%) e TC (26,4%; 23,9%; e 37,3%). O custo operacional efetivo, por animal, em 12 meses, foi R$ 784,58 (US$ 241.40) e R$ 83,90 (US$ 25.81) para TE-S e TC, respectivamente. O TE-S necessita de ajustes para que possa ser indicado como uma alternativa, tecnicamente eficiente e economicamente viável, no controle das parasitoses gastrointestinais em bezerras leiteiras.(AU)

Economic evaluation and efficacy of strategic-selective treatment of gastrointestinal parasites in dairy calves / Avaliação econômica e eficácia do tratamento estratégico-seletivo de parasitos gastrointestinais em bezerras leiteiras

Abstract In the Experimental Farm of the Universidade Federal de Lavras (EF-UFLA), state of Minas Gerais, Brazil, on their day of birth, female Holstein calves were randomly selected and placed into two groups containing fifteen animals each: Strategic-Selective Treatment (S-ST) or Conventional Treatment (CT). In the S-ST, calves were treated after coproparasitological examinations according to criteria established previously by the researchers. Calves in the CT were treated according to the opinion of the veterinarian of EF-UFLA. For statistical analysis, the frequency (%) of fecal samples with count of eggs per gram of feces (EPG) ≥300, count of oocysts per gram of feces (OoPG) ≥500 and fecal samples with count of cysts of Giardia spp. ≥1 were conducted. The overall average frequency of fecal samples with EPG ≥300, OoPG ≥500 and Giardia spp. cysts ≥1, respectively, was similar (p >0.05) between S-ST (20.3%; 17.3%; and 31.5%) and CT (26.4%; 23.9%; and 37.3%). The effective operational cost, per animal, in 12 months, was of R$ 784.58 (US$ 241.41) and R$ 83.90 (US$ 25.81) in S-ST and CT, respectively. The S-ST requires adjustments to be used as a technically efficient and economically viable alternative for the control of gastrointestinal parasitosis in female Holstein calves.

Resumo Na Fazenda Experimental da Universidade Federal de Lavras (FE-UFLA), Minas Gerais, Brasil, no dia do nascimento, bezerras da raça holandesa foram sorteadas de forma aleatória para compor um dos dois grupos, formados por 15 animais cada: Tratamento Estratégico-Seletivo (TE-S) ou Tratamento Convencional (TC). No TE-S, as bezerras foram tratadas após exames coproparasitológicos de acordo com critérios previamente estabelecidos pelos pesquisadores. No TC, as bezerras foram tratadas conforme orientação do veterinário da FE-UFLA. Em ambos grupos, as bezerras foram monitoradas a cada 14 dias, do nascimento até os 12 meses de idade, por meio de exames coproparasitológicos. Para análise estatística, considerou-se a frequência (%) de amostras fecais com contagem de ovos por grama de fezes (OPG) ≥300, contagem de oocistos por grama de fezes (OoPG) ≥500, e amostras fecais com contagem de cistos de Giardia spp. ≥1. A frequência média global de amostras fecais com contagem de OPG ≥300, OoPG ≥500 e cistos de Giardia spp. ≥1, respectivamente, foi similar (p >0,05) entre TE-S (20,3%; 17,3%; e 31,5%) e TC (26,4%; 23,9%; e 37,3%). O custo operacional efetivo, por animal, em 12 meses, foi R$ 784,58 (US$ 241.40) e R$ 83,90 (US$ 25.81) para TE-S e TC, respectivamente. O TE-S necessita de ajustes para que possa ser indicado como uma alternativa, tecnicamente eficiente e economicamente viável, no controle das parasitoses gastrointestinais em bezerras leiteiras.

Metarhizium anisopliae for controlling Rhipicephalus microplus ticks under field conditions.

Metarril SP Organic is a product based on the fungus Metarhizium anisopliae, which was developed for controlling agricultural pests. The present study evaluated the effect of Metarril SP Organic plus 10% mineral oil, for controlling Rhipicephalus microplus under field conditions. Three groups were formed: Control group, which received no treatment; Oil control group, which was bathed only with water, Tween 80 and mineral oil; and Metarril group, bathed in the oil-based formulation Metarril SP Organic. Two treatments per group were performed and to verify the effect of the treatments, all R. microplus ticks between 4.5 and 8.0mm in length on the left side of the cattle were counted on days +7, +14 and +21 after each treatment, and a sample of engorged females was collected for evaluation of biological parameters. The Metarril SP Organic oil formulation showed efficacy ranging from 8.53 to 90.53%. The average efficacy of the oil-based formulation of Metarril SP Organic was 75.09 and 46.59% compared with the groups Control and Oil control, respectively. There were no significant changes in biological parameters of engorged R. microplus females collected from animals. Although there was no significant difference in the amount of ticks between the Oil control and Metarril groups, it is believed that the association of mineral oil with Metarril SP Organic product is effective in R. microplus tick control in field. Thus, this association has potential to be used in strategic control programs of cattle tick.

Integrated control of an acaricide-resistant strain of the cattle tick Rhipicephalus microplus by applying Metarhizium anisopliae associated with cypermethrin and chlorpyriphos under field conditions.

The efficacy of the fungus Metarhizium anisopliae to control ticks has been shown in several in vitro experiments. However, few studies have been undertaken in field conditions in order to demonstrate the applicability of its use as a biological control of ticks and its combination with chemical acaricides. The aim of the present study was to evaluate the efficacy of M. anisopliae to control an acaricide-resistant strain of Rhipicephalus microplus under laboratory and field conditions. First, the compatibility of M. anisopliae strain (TIS-BR03) with commercial acaricides and its potential to control the cattle tick were evaluated in vitro. In general, acaricide treatments had mild effects on fungus viability. In the field experiment, the median of treatment efficacy with acaricide only, M. anisopliae only and combination of M. anisopliae with acaricide were 71.1%, 56.3% and 97.9%, respectively. There is no statistical difference between groups treated with M. anisopliae and acaricide alone. Thus, in this work we have demonstrated the applicability of M. anisopliae use associated or not with chemical acaricides on field conditions in order to control an acaricide-resistant strain of the cattle tick R. microplus.

An isolate of the nematophagous fungus Monacrosporium thaumasium for the control of cattle trichostrongyles in south-eastern Brazil.

A mycelial formulation in sodium alginate pellets of the nematophagous fungus Monacrosporium thaumasium (isolate NF34A) was assessed in the biological control of beef cattle trichostrongyles in tropical Brazil. Two groups of ten male Nellore calves aged 6 months, a fungus-treated group and a control group, were fed on a pasture of Brachiaria decumbens naturally infected with larvae of cattle trichostrongyles. The fungus-treated group received doses of sodium alginate mycelial pellets orally (1 g pellets (0.2 g fungus)/10 kg live weight) twice a week for 12 months. At the end of the study there was a significant reduction (P< 0.01) in the number of eggs per gram of faeces and coprocultures of the fungus-treated group--47.8% and 50.2%, respectively--in relation to the control group. There was a 47.3% reduction in herbage samples, collected up to 0-20 cm from faecal pats, between the fungus-treated and control groups, and a 58% reduction when the sampling distance was 20-40 cm from faecal pats (P< 0.01). The treatment with sodium alginate pellets containing the nematode-trapping fungus M. thaumasium reduced trichostrongyles in tropical south-eastern Brazil and could be an effective tool for the biological control of this parasitic nematode in beef cattle. However, in such a tropical climate with low rainfall the fungal viability can be reduced.