Detection of Malassezia spp. from healthy cattle and cattle with otitis by direct xamination and culture

The occurrence of bovine external otitis in tropical regions is predominantly assigned to parasitic infestations . These infections represent a significant problem and can be associated with vestibular disease and death. Yeasts of the genus Malassezia are members of the normal microbiota on human and animal skin, and may also be associated with bovine parasitic otitis. The purpose of this study was to evaluate the prevalence of the genus Malassezia in healthy cattle and cattle with otitis by direct microscopic examination and culture. Specimens of 1010 cattle were collected with sterile swabs, inoculated onto Mycosel medium, supplemented with olive oil, and incubated at 32oC for one week. In addition, 200 cattle (143 healthy and 57 with otitis) were also evaluated by direct microscopic examination using a Gram staining method to detect Malassezia spp.. Using the direct examination of the specimens no significant difference was observed between the presence of Malassezia spp. from 143 healthy animals (30.7%) and from 57 animals with otitis (26.3%). Culture was positive for Malassezia spp. in 329 (38.12%) of a total of 863 healthy cattle and in 93 (63.27%) of 147 cattle with otitis (

Interação microbiana e metanogênese em ruminantes – uma revisão

A produção animal contribui de forma significativa na emissão de gases de efeito estufa de origem antropogênica. A fermentação entérica e ruminal produz metano que representa o gás de maior relevância nesse efeito. Nesta revisão objetivou-se analisar os efeitos das práticas utilizadas para mitigação da emissão do metano (CH4) na interação microbiológica do rúmen. O CH4 entérico emitido pelos ruminantes resulta da atividade da população de archaeas metanogênicas que desenvolveram relação evolutiva complexa com a comunidade de protozoários ciliados, bactérias e fungos anaeróbicos. Esses microrganismos produzem substratos que são utilizados pelas metanogênicas no metabolismo energético, gerando CH4. Em termos produtivos, representa baixa eficiência na utilização da energia do alimento ingerido, porém, metabolicamente é um processo favorável para o ecossistema ruminal. A manipulação do ambiente ruminal com vista a reduzir a emissão de metano e melhorar a eficiência energética, tem se baseado na melhora da qualidade das pastagens, manejo nutricional e alimentar, seleção e melhoramento genético. Ademais, a utilização dessas práticas resultam em modificações na estrutura microbiana e nos mecanismos fermentativos a curto prazo. Contudo, estudos são recomendados para avaliar os efeitos das diversas técnicas à longo prazo no ambiente ruminal

Consumo e digestibilidade em ovinos alimentados com dietas contendo resíduos da bananicultura

The objective of this work was to evaluate the effects of the inclusion of banana leaf or pseudostem hay in complete diets on the intake, nutrient digestibility, and ruminal short-chain fatty acid production by lambs. A total of 30 Santa Inês x Dorper lambs were allocated to five treatments: 400 g kg-1 Cynodon spp. hay; 200 g kg-1 banana leaf hay + 200 g kg-1 Cynodon spp. hay; 400 g kg-1 banana leaf hay; and 200 g kg-1 banana pseudostem hay + 200 g kg-1 Cynodon spp. hay and 400 g kg-1 banana pseudostem hay. The inclusion of banana crop residues had no effect on dry matter intake, organic matter, crude protein, neutral detergent fiber (NDF), acid detergent fiber, non-fiber carbohydrates, and total carbohydrates, which presented averages of 1,086.8, 1,000.1, 182.7, 374.3, 194.7, 390.2, and 771.6 g per day, respectively. There was a reduction in NDF digestibility with the inclusion of 400 g kg-1 leaf hay, but no differences were observed in the other treatments. The addition of both banana leaf and pseudostem hay can replace Cynodon spp. hay without affecting intake, nutrient digestibility, and ruminal concentration of short-chain fatty acids.O objetivo deste trabalho foi avaliar os efeitos da inclusão de feno de folha ou pseudocaule de banana em dietas completas sobre a ingestão, a digestibilidade de nutrientes e a produção ruminal de ácidos graxos de cadeia curta em cordeiros. Foram utilizados 30 cordeiros Santa Inês x Dorper, alocados em cinco tratamentos: 400 g kg-1 de feno de Cynodon spp.; 200 g kg-1 de feno de folha de bananeira + 200 g kg-1 de feno de Cynodon spp.; 400 g kg-1 de feno de folha de bananeira; e 200 g kg-1 de feno de pseudocaule de banana + 200 g kg-1 de feno de Cynodon spp. e 400 g kg-1 de feno de pseudocaule de banana. A inclusão de resíduos culturais de banana não teve efeito sobre consumo de matéria seca, matéria orgânica, proteína bruta, fibra em detergente neutro (FDN), fibra em detergente ácido, carboidratos não fibrosos e carboidratos totais, cujas médias foram de 1.086,8, 1.000,1, 182,7, 374,3, 194,7, 390,2 e 771,6 g por dia, respectivamente. Houve redução na digestibilidade da FDN com a inclusão de 400 g kg-1 de feno de folhas, mas não foram observadas diferenças nos outros tratamentos. A adição de feno de folha e de pseudocaule de banana pode substituir o feno de Cynodon spp. sem alterar a ingestão, a digestibilidade de nutrientes e a concentração ruminal de ácidos graxos de cadeia curta

Performance of calves fed silage transition milk

O objetivo deste trabalho foi avaliar o desempenho de bezerros da raça Holandesa, aleitados com leite ou silagem de leite de transição diluída em água ou misturada ao leite, bem como realizar análise econômica das dietas. Foram utilizados 18 animais, com peso corporal inicial médio de 36,50±4,03 kg, alojados individualmente em baias. Os animais receberam quatro litros de dieta líquida por dia, durante 54 dias. Os dados de consumo, ganho de peso diário, medidas de crescimento e conversão alimentar foram analisados em parcelas subdivididas; e o peso corporal final, o ganho total e a ocorrência de diarreia foram analisados em delineamento inteiramente casualizado. A silagem de leite de transição não alterou o consumo de concentrado e o total de matéria seca, nem a ocorrência de diarreia. O desempenho dos animais foi reduzido, quando a silagem foi diluída em água, o que resultou em menor peso final e menor ganho total de peso. Os animais tratados com silagem misturada ao leite tiveram desempenho similar aos tratados com leite, o que possibilita menor custo por quilograma de ganho de peso total e se mostra como opção viável para o aleitamento de bezerros leiteiros.The objective of this work was to evaluate the performance of Holstein calves fed with milk or transition milk silage diluted on water or mixed with whole milk, as well as to determine the economic viability of the diets. Eighteen calves, with an average initial body weight of 36.50±4.03 kg, were individually housed in stalls. The animals were fed four liters of the liquid diet a day, during 54 days. Consumption data, daily weight gain, growth measurements, and feed conversion were analyzed in split plots. Final body weight, total weight gain, and occurrence of diarrhea were analyzed in a completely randomized design. Transition milk silage did not affect concentrate intake, total dry matter intake and the occurrence of diarrhea. Animal performance was reduced when silage was diluted on water, resulting in lower final weight and lower total weight gain. Animals treated with transition milk silage mixed with whole milk had a similar performance to the ones treated with whole milk, which allows a lower cost per kilogram of total weight gain, and shows to be a viable option for the feeding of milking calves

Anthelmintic activity of Annona crassiflora leaves against Haemonchus contortus: part 1: in vitro inhibition of the hatchability and larval development

We evaluated the activity of Annona crassiflora leaves against Haemonchus contortus resistant to albendazol.  Aqueous (AE), ethanolic (EE) and ethyl acetate (EAE) extracts were produced and the predominant presence of flavonoids was observed in HPLC-DAD chromatograms. Initially we evaluated the larval development inhibition (LDI) of dry A. crassiflora leaf powder or its AE directly in fecal quantitative cultures. The efficacies of the extracts, with or without tannins, on egg hatching inhibition (EHI) were investigated reveling that the EE was the most effective (LC90 = 8.96 mg/mL). However, after tannin removal, AE showed the highest activity (LC90 = 4.27 mg/mL). In the LDI test, the LC90 of AE was < 6.25 mg/g of fecal culture and to leaf powder of leaves was 69.14 mg/g.  High efficacies of AE and EE for EHI were detected and the tannins were not the main active metabolites. The anthelmintic potential of this plant could be attributed to association between flavonoids and other metabolites

Anthelmintic activity of Annona crassiflora leaves against Haemonchus contortus: part 2: efficacy in vivo and blood parameters

In this study we evaluated the oral toxicity of leaf extracts of Annona crassiflora of for mice and the blood and parasitological parameters of lambs experimentally infected with Haemonchus contortus and treated with leaves of this plant. The highest dose of AE (aqueous extract) administered to mice (203.0 mg/kg bw) was well tolerated, suggesting low toxicity. At necropsy, macroscopic examination revealed no abnormalities of the evaluated viscera.  Lambs infected with the nematode were divided one group treated with leaf powder and a control group that did not treat. Split-plot design analysis was performed where the treatments were defined as plots and three periods of collection were defined as subplots. Similar performances to weight gain were observed among the lamb groups. The oral administration of leaf powder at 2.75g /Kg bw did not alter the physiological blood parameters in comparison to untreated lambs; however, this dose was not efficient to fecal egg reduction.    We consider that other formulations and administration protocols should be evaluated to promote an effective alternative control using the leaves of this plant

Control of Haematobia irritans in the Minas Gerais Semiarid

Background: Beef cattle is considered to be one of the most important economic activities, however, it presents problems in the production chain such as the occurrence of parasites that reduce the growth, performance, productivity and may cause mortalities occasionally. The chemical control is the most used alternative to reduce ectoparasites. Nevertheless, inappropriate management of insecticides has contributed to the selection of population resistant to the products available on the market. This paper aimed to evaluate the practices of management and the application of insecticides used to control horn flies in farms of dairy cattle in the North of the state of Minas Gerais.Materials, Methods & Results: It was visited 62 rural properties, which produce milk. Semi-structured questionnaires were applied in order to obtain information on the characteristics of the properties (location, size and type of the cattle), on the knowledge about the epidemiology of the horn flies, and on the practices adopted to the control of those parasites. The practices adopted include the moment of application of the insecticides, frequency of the cattle treatment, used products, method of application, number of animals treated, and choice and substitution criteria of insecticides. The data collected were tabulated in contingency tables, and they were analyzed using the chi-square test, considering a significance of 5%. The racial composition of the cattle in the farms was mainly mixed-race of unknown origin, representing 77% of the animals evaluated. In this research, it was reported a greater incidence of horn flies infestation on adult beef herd, and 23.6% of the producers reported occurrences of infestation in the whole herd, not differing by categories. The infestation peaks of the fly occurred from November to March. It was also found a greater frequency of pyrethroid use in the region (P < 0.001), where 43.1% of the producers used associations of pyrethroid or organophosphate to control the flies, high efficiency being reported. From the properties assessed, 92% presented inadequacy in the practices of control of horn flies, for instance, the lack of using cattle manure tank, the accumulation of open waste, the lack of rotation of insecticides, which can favor the selection of resistant flies.Discussion: In this paper, it was reported 77.19% of predominance of Haematobia irritans infestation from November to March mainly in animals with a higher percentage of European or mixed-race genetics. Such results corroborate with the literature, because it was verified the influence of race and hair color in the level of infestation in the animals, although, in the same race, each individual presents different susceptibilities. Taurine beef cattle are more susceptible to infestation by horn flies than zebu cattle. Thus, the lower the proportion of zebu cattle genetics in the herd, the greater the infestation. Taurine beef cattle are more infested because shows a greater number of sebaceous glands and greater concentration of testosterone being attractive before the calves castrated, cows, and after, young animals. Cypermethrin was predominant in most part of the commercial insecticides used in the properties to control this ectoparasite, which could be justified by the large number of products available on the market with such compound in the formulations. The high efficiency of the associations of the insecticides reported by the producers could justify itself by the presence of active ingredients with different mechanisms of action. However, the limitation on the use of these associations is that not always the chemical compounds contained in the drug act simultaneously, being able to favor the selection of parasites resistant to different insecticides present in these formulations