Infecção por Neospora spp. e Toxoplasma gondii em rebanhos ovinos no Rio Grande do Sul, Brasil

Neospora caninum and Toxoplasma gondii are coccidian parasites (protozoa: Apicomplexa) that cause reproductive losses in ruminants. Although, in sheep, abortion is generally related to T. gondii, potential damage caused by N. caninum must be considered. The aims of this study were to evaluate the frequencies of antibodies against Neospora spp. and T. gondii, and to identify the risk factors related to neosporosis and toxoplasmosis in sheep from ten flocks located in Central-Western, Northwestern, Southwestern, and Southeastern mesoregions of the Rio Grande do Sul state, southern Brazil. Blood samples were collected from 300 sheep (30 per flock) and an epidemiological questionnaire was completed by the farmers. The presence of canids, felids, and rodents, the sources of water for the animals, and their reproductive history were investigated as potential epidemiological factors related to the studied infections. Serum samples were tested by the indirect fluorescent antibody test for the presence of antibodies against Neospora spp. (cutoff 1:50) and T. gondii (cutoff 1:64), with respective frequencies detected being 16.3% (49/300) and 41.3% (124/300). Seropositivity to both parasites was observed in 8% (24/300) of the animals. Neospora spp. and T. gondii were present in 90% (9/10) and 100% (10/10) of the flocks, respectively. The presence of cats in the pastures, pens, and barns was significantly associated (p=0.047) with high frequencies (53.3% to 70%) of antibodies against T. gondii in the flocks. However, no associations were detected (p>0.05) between each of the other risk factors and the frequency of antibodies against Neospora spp. or T. gondii. Results of this study showed a broad distribution of both protozoa in evaluated sheep flocks.Neospora caninum e Toxoplasma gondii são parasitos coccídeos (protozoa: Apicomplexa) que causam perdas reprodutivas em ruminantes. Embora o aborto em ovinos geralmente esteja associado a T. gondii, potenciais perdas causadas por N. caninum devem ser consideradas. Os objetivos deste estudo foram avaliar as frequências de anticorpos contra Neospora spp. e T. gondii e identificar fatores de risco para neosporose e toxoplasmose em ovinos de dez rebanhos localizados nas mesorregiões Centro- Ocidental, Noroeste, Sudoeste e Sudeste, no estado do Rio Grande do Sul, Brasil. Foram coletadas amostras de soro sanguíneo de 300 ovinos (30 por rebanho) e foi aplicado inquérito epidemiológico aos proprietários dos rebanhos. A presença de canídeos, felídeos e roedores, as fontes de água dos animais, e seu histórico reprodutivo, foram investigados como potenciais fatores epidemiológicos relacionados às infecções estudadas. As amostras de soro foram testadas pela técnica de imunofluorescência indireta para presença de anticorpos contra Neospora spp. (ponto de corte 1:50) e T. gondii (ponto de corte 1:64), sendo encontradas frequências de 16,3% (49/300) e de 41,3% (124/300), respectivamente. Soropositividade para ambos os agentes foi observada em 8% (24/300) dos animais. Neospora spp. e T. gondii estavam presentes em 90% (9/10) e 100% (10/10) dos rebanhos, respectivamente. A presença de gatos nas pastagens, currais e depósitos esteve significativamente associada (p=0,047) com altas frequências de anticorpos (entre 53,3% a 70%) contra T. gondii nos rebanhos. Não houve associação (p>0,05) entre os demais fatores de risco e a frequência de anticorpos contra Neospora spp. ou T. gondii. Os resultados deste estudo demonstraram ampla distribuição de ambos os protozoários nos rebanhos ovinos avaliados

Efficacy of commercial synthetic pyrethroids and organophosphates associations used to control Rhipicephalus (Boophilus) microplus in Southern Brazil

<div><p>Abstract This study evaluated the acaricidal efficiency of synthetic pyrethroids (SP) associated with organophosphates (OP) against Rhipicephalus (Boophilus) microplus populations in the state of Rio Grande do Sul, Southern Brazil. Ticks were collected in 54 cattle farms and tested using in vitro adult immersion test against four commercially available acaricide mixtures of SP and OP. Only one of four acaricides, comprising a mixture of cypermethrin, chlorpyrifos, and fenthion, had a mean efficiency higher than 95%, and was effective in 94.44% (51/54) of the cattle farms tested. The acaricide with a mixture of cypermethrin, chlorpyrifos, and citronelall had the lowest mean efficiency (62.11%), and was effective in 29.62% (16/54) of cattle farms tested. Furthermore, R. (B.) microplus in Southern Brazil exhibited differing degrees of resistance to SP and OP mixtures. The results suggest that the presence of fenthion contributes to the higher efficiency of the formulation with this active principle. This is possibly due to its recent commercial availability, as tick populations have been lower challenged with this product. Monitoring the resistance of ticks to carrapaticides is essential to maximize the efficiency of these products in the control of R. (B.) microplus.</p></div

ANÁLISE ECONÔMICA DETERMINÍSTICA DA TERMINAÇÃO EM CONFINAMENTO DE NOVILHOS ABATIDOS COM DISTINTOS PESOS

The aim of this study was to evaluate the economic viability of feedlot-finished steers through financial indicators of risk and return, via deterministic analysis, based on average values quotations practiced in Rio Grande do Sul state in the years 2004-2012. We used 18 Charolais steers with average initial age of 30 months and average initial weight of 297.0kg ± 11.5kg. We evaluated three predetermined slaughter weights: 420, 460 and 500kg, being the weights obtained of 421, 461 and 495kg, respectively. Variable costs represented 98% of total cost, and of these, the most representative were purchase of feeder cattle and food (forage + concentrate). The estimates of the financial indicators to slaughter weights of 421, 461 and 495kg were, respectively: R$-266.30, -323.49 and -417.18 for gross margin; R$ -289.70, -440.59 and 346.90 for net margin; R$-344.89, -419.93 and -536.24 for profit; R$ -316.78, -381.92 and -483.67 for net present value; 0.85, 0.83 and 0.81 for index benefit:cost, -2.65%, -2.52% and -2.58% for additional return on investment; -5.02%, -4.57% and -4.56% for the internal rate of return (a.m.); and 7.05, 8.37 and 9.86 months for discounted payback. Although these results indicate infeasibility of termination at any slaughter weight, lower weights resulted in lower economic losses, making this technology of high economic risk

Deterministic economic analysis of feedlot Red Angus young steers: slaughter weights and bonus

The joint analysis of indicators of the investment project is very relevant in making decisions, resulting in more consistent information regarding risk assessment and its confrontation with the possibility of return. This research aimed to evaluate the economic feasibility of Red Angus young steers finished in feedlot, slaughtered at 340, 373, 396 or 430kg with use of various financial indicators, marketed with or without bonus. The purchase of feeder cattle and feeding were variable costs with a higher share in the total cost. In the analysis with bonus, the regression analysis to gross margin, net margin, net present value, benefit:cost index and additional return on investment showed quadratic behavior, with the point of maximum at 406kg (R$185.17), 406kg (R$ 161.76) , 393kg (R$128.29), 392kg (1.12), 392kg (11.98$ 110.31 and R$ 86.90, respectively), while for the other indicators, there was a linear reduction as an increase in slaughter weight

Economic analysis of finishing feedlot steers fed different proportions of sugar cane and concentrated

Submitted by Franciele Moreira ([email protected]) on 2017-10-25T16:29:55Z No. of bitstreams: 2 Artigo - Paulo Santana Pacheco - 2014.pdf: 680165 bytes, checksum: da3de645aff54ce4b0192df2ce71ac33 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2017-10-26T11:12:34Z (GMT) No. of bitstreams: 2 Artigo - Paulo Santana Pacheco - 2014.pdf: 680165 bytes, checksum: da3de645aff54ce4b0192df2ce71ac33 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2017-10-26T11:12:34Z (GMT). No. of bitstreams: 2 Artigo - Paulo Santana Pacheco - 2014.pdf: 680165 bytes, checksum: da3de645aff54ce4b0192df2ce71ac33 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-04Objetivou-se avaliar a economicidade da terminação em confinamento de novilhos mestiços zebuínos, recebendo dietas com 40, 60 ou 80% de concentrado (base na matéria seca), através de indicadores financeiros. Foram utilizados 30 animais com idade e peso médios iniciais de 26 meses e 348 ± 32 kg, respectivamente, alimentados por 90 dias, sendo abatidos com peso médio de 449 ± 40 kg. O delineamento experimental foi o inteiramente casualizado, com três tratamentos e dez repetições, procedendo-se análise de regressão. Houve incremento linear no custo total por animal com o aumento no nível de concentrado, oriundo das diferenças verificadas em alguns itens do custo variável, sendo que o custo com alimentação volumoso reduziu e, com a alimentação concentrado, outros e oportunidade do capital investido aumentaram com o incremento no nível de concentrado da dieta. Quanto aos indicadores financeiros, os níveis de concentrado de 40, 60 e 80% apresentaram similaridade (P>0,05), sendo as estimativas médias de R$-119,77 para margem bruta, R$-129,63 para margem líquida, de R$-162,14 para lucro, de R$-144,01 para valor presente líquido, de 0,8994 para índice benefício:custo e -10,06% para retorno adicional sobre o investimento. As estimativas foram de -3,84% para taxa interna de retorno, de 0,1370 para relação taxa mínima de atratividade:taxa interna de retorno e 5,58 meses para payback descontado. Os indicadores financeiros evidenciaram inviabilidade econômica da terminação em confinamento, com menor retorno e maior risco conforme incrementou o nível de concentrado na dieta. Houve concordância entre os valores dos indicadores utilizados, demonstrando sua relevância na tomada de decisão.The objective of this study was to evaluate the economic viability of feedlot finishing of crossbred zebu, fed diets with 40, 60 or 80% concentrate (dry matter basis), by financial indicators. A total of 30 animals with age and initial weight average of 26 months and 348 ± 32 kg, respectively, fed for 90 days and slaughtered at an average weight of 449 ± 40 kg. The experimental design was completely randomized with three treatments and ten replicates, proceeding to the regression analysis. There was a linear increase in the total cost per animal with increasing concentrate level, arising from differences in some items of variable cost, being the cost with forage feed reduced and feed concentrate, other and opportunities on invested capital increased with increase in the level of dietary concentrate. As for financial indicators, the concentrate levels of 40, 60 and 80% had similar (P> 0.05), being the average estimates of R$-119.77 to gross margin, R$ -129.63 to net margin, from R$-162.14 to profit, R$ -144.01 to net present value, rate of 0.8994 for the benefit:cost and -10.06% for additional return on investment. The estimates were -3.84% for the internal rate of return, rate of 0.1370 to minimum rate of attractiveness: internal rate of return and discounted payback of 5.58 months. The financial indicators showed economic infeasibility of feedlot finishing, a lower return and higher risk with increased as the level of concentrate. There was agreement between the values of the indicators used, showing its relevance in decision making

Bovine upper alimentary squamous cell carcinoma associated with bracken fern poisoning: Clinical-pathological aspects and etiopathogenesis of 100 cases.

Upper digestive tract (UDT) cancer is rare in cattle, however in Southern Brazil, the UDT squamous cell carcinomas (SCCs) are relatively common and have been associated with bracken fern consumption and the presence of papillomas. Although a theory of pathogenesis considers bovine papillomavirus type 4 (BPV-4) as a cofactor in the development of these SCCs, some aspects of the etiopathogenesis of this disease need to be more investigated. In fact, detection of BPV-4 in UDT papillomas is scarce in other regions of the world and has not been performed in Brazil. Therefore, this study had two aims: 1) to analyze the epidemiological, clinical and pathological aspects of 100 natural cases of SCCs in the UDT of cattle grazing on bracken fern (Pteridium arachnoideum) highly contaminated areas, investigating the associations between these parameters; and 2) to investigate the presence of papillomavirus DNA by polymerase chain reaction (PCR) in the UDT papillomas (n = 47) from 30 cattle that also had UDT SCCs. There were statistically significant associations between clinical signs and tumor localization in the UDT; between histological grade of differentiation and tumor localization; and a trend towards significant association between histological grade of differentiation and presence of metastases. The average age of cattle with oropharyngeal SCCs was 7.39 years, with statistically significant difference comparing to cattle with esophageal SCCs (8.6 years). No statistical association was observed among other clinical-pathological parameters (growth pattern and primary site of the tumor) analyzed. No BPV DNA was detected in papillomas by PCR. Therefore, these results suggest the possibility that papillomas of the UDT are not necessarily associated with BPV infection