Relação entre desempenho e infecções por nematódeos gastrintestinais em bovinos Nelore em crescimento

Este estudo teve por objetivo verificar a associação entre o desempenho e a carga parasitária de 28 machos inteiros da raça Nelore (a partir de um ano de idade), naturalmente infectados por nematódeos gastrintestinais. de novembro de 1999 a junho de 2000, os animais foram pesados quinzenalmente, período no qual foram colhidas amostras de fezes e de sangue para a realização, respectivamente, de exames coprológicos e sangüíneos. Os dados da contagem de ovos por grama de fezes (OPG) ajustaram-se ao modelo de distribuição binomial negativa, indicando que a distribuição de nematódeos no rebanho é agregada. Não ficou evidenciada associação entre ganho de peso e contagem de OPG, e entre contagem de OPG e volume globular (VG). de 10 coeficientes de correlação entre ganho de peso e VG, oito foram negativos, mas apenas dois significativos (P<0,05). As estimativas de repetibilidade da contagem de OPG, LOG (OPG+1) e VG foram de 0,26, 0,25 e 0,33, respectivamente. Cooperia punctata foi a espécie mais freqüentemente encontrada parasitando os animais. Além dessa espécie, foram detectados os seguintes nematódeos: Haemonchus placei, Haemonchus similis, Trichostrongylus axei, Bunostomum phlebotomum e Oesophagostomum radiatum. O parasitismo por nematódeos gastrintestinais aparentemente não prejudicou o desenvolvimento dos animais estudados.

Moxidectin-resistant nematodes in cattle in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological and morphometric comparisons of the first zoea of four species of purse crabs (Decapoda: Brachyura: Leucosiidae) from the Brazilian South Atlantic

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differential benthic occupation by crabs in the Ubatuba bay, São Paulo, Brazil

The goal of this work was to examine the occurrence of brachyurans in soft bottom sublittoral habitats and their association with some environmental factors. The relative abundance of crabs in two depth strata (from 4.5 to 9 m and from 9 to 18 m) was quantified. Crabs were collected with an otter-trawl with 3.7 m of mouth opening and 12-mm mesh in the cod end. Monthly sampling, consisted of a single trawl in each stratum during a 1-yr period, were carried out. Fifteen brachyuran and six anomuran species were found, including Callinectes ornatus Ordway, 1863; Callinectes danae Smith, 1869; Hepatus pudibundus (Herbst, 1785); Libinia spinosa H. Milne-Edwards, 1834; Persephona punctata (Linnaeus, 1758), and P. mediterranea (Herbst, 1794), which were the most abundant and frequent in the area. The most abundant swimming crabs in both strata were C. ornatus and C, dan(re. Size differences in C. ornatus were observed between strata, suggesting a spatial separation of juveniles and adult crabs.

Endectocide activity of a new long-action formulation containing 2.25% ivermectin+1.25% abamectin in cattle

The present work aimed to evaluate the endectocide activity of a new injectable long-action formulation, containing ivermectin (IVM) and abamectin (ABA). In each one of the four experiments performed, the following groups were formed: group I: 2.25% IVM (450 mu g/kg) + 1.25% ABA (250 mu g/kg), group II: 3.15% IVM (630 mu g/kg) and group III: control. Eighteen bovine naturally infected by gastrointestinal nematoda were selected for anthelmintic evaluation and necropsied on posttreatment day (PTD) 14 to estimate the total parasitic burden. For the Rhipicephalus (Boophilus) microplus field trial, 30 bovine were selected by means of counts of semi-engorged R. (B.) microplus and the therapeutic and residual efficacy evaluated by tick counts on PTDs 1, 3, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84 and 91. In the stall test, 15 calves were artificially infested with 5000 R. (B.) microplus (Mozzo strain) larvae three times a week and daily collections of all the engorged female ticks detached from each calf were performed until the PTD 80. Forty bovine naturally infected with Dermatobia hominis larvae were selected and the number of larvae was counted by visual and tactile inspection on PTDs 3, 7, 14, 28, 35, 49, 63, 77, 91 and 105. In this trial, a formulation containing 1% doramectin (200 mu g/kg) was also used. IVM + ABA formulation and 3.15% IVM eliminated four of the eight species of nematode identified. The anthelmintic efficacy of the avermectins association against Haemonchus placei, Cooperia spatulata and C. punctata was 89.64%, 98.84% and 97.69%, while 3.15% IVM achieved 30.98%, 84.79% and 75.56%, respectively. The two formulations evaluated showed reduced acaricide action on the PTD I and 3, reaching high efficacy percentages from PTD 14 onward. The IVM + ABA showed efficacy above 95% in the period between PTDs 21 and 49. In the stall test, it observed no difference (P > 0.05) between the two formulations regarding the R. (B.) microplus counts during the entire evaluation period. IVM + ABA reduced the number of ticks from the PTD 1 to 77 (P < 0.05) and 3.15% IVM reduced (P < 0.05) the tick number from PTD 4 up to PTD 80. The three endectocides showed no difference (P > 0.05) regarding the number of D. hominis larvae and prevented this parasite reestablishment until PTD 105. These results indicate that the IVM + ABA association showed higher anthelmintic activity and similar efficacy against arthropods to the formulation containing 3.15% IVM. (C) 2008 Elsevier B.V. All rights reserved.

Influência de herbicidas em macrófitas aquáticas

The effects of the herbicides atrazine, 2,4-D, glyphosate (direct and rodeo) and trifluralin were determined on the growth and death of fronds of the aquatic macrophytes Spirodela punctata (G.F.W. Meyer) Thompson and Salvinia minima Baker, through three series of concentrations of each herbicide in climatic chamber (3000 lux, 12/12 hours photoperiod, temperature 23 ± 1°C). After seven days, the concentrations of series 1 (0.025, 0.125, 0.625 and 3.125 mg.L -1) inhibited the growth of Salvinia minima. In Spirodela punctata, only the herbicides rodeo and trifluralin caused growth inhibition. These concentrations did not caused death of fronds in the species. The concentrations of series 2 (40, 60, 80 and 100 mg.L -1) of the herbicides 2,4-D, direct e trifluralin decreased growth of Salvinia minima; death of fronds was caused by 2,4-D and trifluralin to Salvinia minima, and by direct and trifluralin to Spirodela punctata. For the series 3 (200, 400, 600, 800 and 1000 mg.L -1), the herbicide 2,4-D caused growth decrease of both species. The herbicides rodeo and trifluralin showed to be the most lethal for both species. The herbicide atrazine caused death of fronds in Spirodela punctata.

Sheep and cattle grazing alternately: Nematode parasitism and pasture decontamination

Three grazing management systems were compared to examine pasture decontamination of gastrointestinal nematode parasites (GIN) of sheep (Ovies aries) and cattle (Bos taurus). They consisted of sheep and cattle grazing paddocks alternately for 32, 96 or 192 days over 2 years. Pastureland (8.43 ha) was subdivided into six areas of eight paddocks each to produce an eight-paddock rotational grazing system. Every paddock was grazed for 4 days and then rested for 28 days. Sixty-six Ile de France ewes and 12 steers were randomly divided into three groups (22 sheep and four cattle per group). Each grazing system included a cattle area and a sheep area. Sheep and cattle interchanged areas every 32 days in system 1 (Group 1), every 96 days in system 2 (Group 2) and every 192 days in system 3 (Group 3). Fecal examination and larvae counting on pasture were performed every 32 days. During summer, winter and spring 2005, tracer lambs free of nematode infection were introduced into each sheep group and later sacrificed for quantification and identification of GIN species. All cattle were sacrificed for the same purpose. The main parasites found in tracer lambs were Haemonchus contortus and Trichostrongylus colubriformis, and in cattle, Haemonchus similis, Cooperia punctata and Oesophagostomum radiatum. Pasture contamination by sheep-infective GIN larvae was considerably reduced after 96 or 192 days of cattle grazing. Cross-infections between sheep and cattle GIN were not significant, which suggested that integrated grazing using such animals could be used for pasture decontamination. However, as effective anthelmintics were not available, decontamination was not sufficient for proper prophylaxis of GIN infections in Ile de France sheep, which are quite susceptible to such parasites. © 2007 Elsevier B.V. All rights reserved.

Resistance against gastrointestinal nematodes in Crioulo Lageano and crossbred Angus cattle in southern Brazil

Gastrointestinal nematode (GIN) infection is a major cause of production losses in cattle. This study was carried out to evaluate the natural resistance against nematode infection in Crioulo Lageano and crossbred Angus male calves. Crioulo Lageano is a local cattle breed in the state of Santa Catarina, in southern Brazil. Ten weaned calves of each breed were grazed together on pasture and naturally infected with nematodes between July 2009 and December 2010. Once every 28 days, we collected fecal and blood samples for parasitological and immunological tests, as well as recording body weights. After 19 samplings, all animals were slaughtered for quantification and identification of GINs. We found that the animals had been infected with the following nematode species, in decreasing order by the mean number of specimens: Trichostrongylus axei, Cooperia punctata, Ostertagia ostertagi, Haemonchus placei, Oesophagostomum radiatum, and Trichuris spp. There were no significant differences between the Crioulo Lageano and crossbred Angus groups in terms of worm burden or nematode fecal egg count, nor in terms of the mean levels of immunoglobulin (G and A) against C. punctata and H. placei antigens, except in IgA mean level in abomasal mucus against H. placei adult worms that was significantly higher in crossbred Angus cattle (p<0.05). At the end of the study, the crossbred Angus cattle were heavier than were the Crioulo Lageano cattle (mean live weight, 507.35 and 390.3. kg, respectively). Comparative parasitological and immunological evaluation revealed no difference between two breeds in terms of their natural resistance against GINs. © 2012 Elsevier B.V.

Persistent efficacy of 3.5% doramectin compared to 3.15% ivermectin against gastrointestinal nematodes in experimentally-infected cattle in Brazil

The present study aimed to evaluate the persistent efficacy of a 3.5% doramectin* (700μg/kg) formulation compared to 3.15% ivermectin** (630μg/kg) treatment, administered subcutaneously at a dose of 1mL/50kg body weight in cattle experimentally infected with gastrointestinal nematodes. Seventy-two male crossbred Holstein cattle that were negative for helminth infection were divided into nine groups. Treatments of 3.5% doramectin (Groups 2, 4, 6 and 8) and 3.15% ivermectin (Groups 3, 5, 7 and 9) were administered on days 49, 42, 35 and 28 prior to challenge with infectious nematode larvae (L3). Animals in the control group (Group 1) received saline solution on day 49 before challenge. Beginning on day zero, each animal received 50mL orally of a mixed culture containing approximately 3,000 third stage larvae (L3) of Haemonchus (60%), Oesophagostomum (20%), Cooperia (15%) and Trichostrongylus (5%) for seven consecutive days, resulting in a total challenge of 21,000 larvae/animal. Due to the large number of cattle, autopsies were performed between days 28 and 35 after the last day of inoculation. The formulation containing doramectin (700 mcg/kg) achieved persistent efficacy against H. placei and C. punctata for 49 and 35days, respectively. The persistent efficacy of ivermectin (630 mcg/kg) against H. placei lasted for 49days, but this treatment was ineffective against C. punctata. Both formulations demonstrated persistent efficacy against T. axei for 49days. The persistent efficacy of doramectin (700 mcg/kg) and ivermectin (630 mcg/kg) lasted for 49 and 42days against O. radiatum, respectively. © 2012 Elsevier Ltd.

Epibiosis in decapod crustaceans by stalked barnacle Octolasmis lowei (Cirripedia: Poecilasmatidae)

Stalked barnacles Octolasmis lowei Darwin, 1851 are frequently found attached to decapod crustaceans. Their epibiotic association depends on many factors, which are mainly related to characteristics of the host's biology. This study evaluated the infestation and distribution of stalked barnacles in the branchial chambers of crabs, and analyzed the data with respect to the host's sex, maturity stage, molt cycle and size. The crab species Arenaeus cribrarius Lamarck, 1818, Callinectes danae Smith, 1869, Callinectes ornatus Ordway, 1863, Hepatus pudibundus Herbst, 1785, Libinia ferreirae Brito Capello, 1871, and Persephona punctata Linnaeus, 1758 were sampled and found to be infested by O. lowei. No juvenile crabs were infested. The prevalence of infestation by O. lowei was significantly different among C. danae, C. ornatus, and H. pudibundus males and females. All infested hosts were in the intermolt period. The mean size of infested crabs was larger than that observed for non-infested individuals. Internally, stalked barnacles were concentrated on the central gills or walls and floor of branchial chambers, suggesting that these gills provide more favorable conditions for the settlement and development of these epibionts. These results highlight the relationship between epibiont infestation and host biology, as well as the role of decapod crustaceans as a suitable substrate for the development of stalked barnacle O. lowei. © 2013 Sociedade Brasileira de Zoologia All rights reserved.

Relative growth, sexual maturity, and breeding season of three species of the genus Persephona (Decapoda: Brachyura: Leucosiidae): A comparative study

The relative growths of Persephona lichtensteinii, P. mediterranea, and P. punctata were investigated on the south-eastern Brazilian coast, focusing on differences in the growth rates between immature and mature phases, the onset of morphological sexual maturity, and the breeding seasons of these species. Crabs were collected every two months from January 1991 through to November 1992, from a shrimp fishing boat equipped with two otter-trawl nets. Significant differences in the patterns of body growth were observed between immature and mature phases of all three species. Changes in the growth rates of the chelipeds (males) and abdomen (females) observed for P. lichtensteinii, P. mediterranea, and P. punctata, seem to be related to the puberty moult for both sexes. Males of P. mediterranea and P. punctata reached larger mean sizes of carapace width than females, whereas no difference was recorded for P. lichtensteinii. The body size at which 50% of males attained sexual maturity was also larger in P. mediterranea and P. punctata, and smaller in P. lichtensteinii. The absence of a pronounced sexual dimorphism and the size at the onset of sexual maturity observed only for P. lichtensteinii might be explained by distinct reproductive strategies of males. The presence of ovigerous females during the entire sampling period suggests that all three species have a continuous reproduction pattern at the Ubatuba region. Future studies on the population structure, functional maturity, and mating system should improve the understanding of factors driving the biology and ecology of these species at a subtropical region. © Marine Biological Association of the United Kingdom 2013.

Palinologia do grupo Itararé em Salto, Estado de São Paulo (Bacia do Paraná, carbonífero superior)

Pós-graduação em Geologia Regional - IGCE

Atividade endectocida e desenvolvimento ponderal comparativos entre bovinos medicados com duas formulações de ivermectina (4% e 3,15%)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diagnóstico da resistência de nematódeos à ivermectina (630 e 700 mcg/Kg) em bovinos necropsiados prodedentes das regiões Sul e Sudeste do Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Parâmetros farmecocinéticos e atividade endectocida de uma nova formulação contendo avermectinas, via tópica (pour-on), em bovinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)