Caracterização do microambiente em secção transversal de um galpão do tipo "free-stall" orientado na direção norte-sul

O trabalho teve o objetivo de caracterizar o microambiente climático das baias de um galpão de confinamento para gado leiteiro, modelo "free-stall", no sentido transversal da instalação. O "free-stall" é orientado na direção norte-sul, localizado em Marechal Cândido Rondon, região Oeste do Paraná, com capacidade para abrigar 40 vacas em lactação (40 baias). Visando à determinação do Índice de Temperatura do Globo e Umidade (ITGU) e da Carga Térmica de Radiação (CTR), foram instalados quatro globos negros, no centro de baias dispostas no sent ido transversal, dispondo dois globos no lado oeste e dois globos no lado leste (separados pelo corredor de alimentação). Lateralmente ao galpão, no lado leste, havia vegetação a 4 m da instalação, que promovia sombreamento nas primeiras horas do dia. Pode-se concluir que, nas primeiras horas do dia, não há diferença significativa entre os valores de ITGU e CTR encontrados, indicando que o sombreamento, devido à vegetação, foi capaz de amenizar os efeitos da radiação solar. Às 17 h 30 min, verificou-se que há ocorrência de maiores valores, tanto de ITGU quanto de CTR, nas baias localizadas no lado oeste do "free-stall".

Análise do investimento em climatização para bovinos de leite em sistema de alojamento free-stall

A dificuldade de adaptação das raças leiteiras européias no Brasil afeta diretamente o setor produtivo de leite. As condições climáticas do País são desfavoráveis, e o desenvolvimento de novas tecnologias é imprescindível para que o potencial genético e a capacidade de conversão alimentar sejam evidenciados nos animais. Dessa forma, a análise econômica do investimento na climatização de instalações do tipo free-stall torna-se necessária para estimar os aspectos relacionados à rentabilidade, capacidade de pagamento e tempo necessário para recuperar o capital investido. O objetivo deste trabalho foi o de avaliar a influência da climatização no processo produtivo de bovinos de leite e realizar uma análise econômica do investimento. Foram utilizadas 470 vacas com características genéticas e morfológicas homogêneas, de alta produção, analisadas em dois períodos semelhantes. Os cálculos do investimento foram efetuados por meio do programa Excell®. Os resultados das análises indicam que deve haver retorno do capital investido em curto prazo (57 dias).

Prediction of free-stall occupancy rate in dairycattle barns through fuzzy sets

The goal of this study was to develop a fuzzy model to predict the occupancy rate of free-stalls facilities of dairy cattle, aiding to optimize the design of projects. The following input variables were defined for the development of the fuzzy system: dry bulb temperature (Tdb, °C), wet bulb temperature (Twb, °C) and black globe temperature (Tbg, °C). Based on the input variables, the fuzzy system predicts the occupancy rate (OR, %) of dairy cattle in free-stall barns. For the model validation, data collecting were conducted on the facilities of the Intensive System of Milk Production (SIPL), in the Dairy Cattle National Research Center (CNPGL) of Embrapa. The OR values, estimated by the fuzzy system, presented values of average standard deviation of 3.93%, indicating low rate of errors in the simulation. Simulated and measured results were statistically equal (P>0.05, t Test). After validating the proposed model, the average percentage of correct answers for the simulated data was 89.7%. Therefore, the fuzzy system developed for the occupancy rate prediction of free-stalls facilities for dairy cattle allowed a realistic prediction of stalls occupancy rate, allowing the planning and design of free-stall barns.

Anti-Rickettsia spp. antibodies in free-ranging and captive capybaras from southern Brazil

Capybaras (Hydrochaeris hydrochaeris) are among the main hosts of Amblyomma spp. ticks, which is able to transmit Rickettsia species to human beings and animals. Since they are often infested with potential vector ticks, capybaras may be used as sentinels for rickettsiosis, such as the Brazilian Spotted Fever. The aim of the present study was to determine the prevalence of antibodies against Rickettsia spp. using the indirect immunofluorescence assay (IFA) in 21 free-ranging and 10 captive animals from the Zoological Park of the 'Bela Vista Biological Sanctuary' (BVBS), Itaipu Binational, Foz do Iguaçu, Southern Brazil. Antigens of six rickettsial species already identified in Brazil (Rickettsia rickettsii, R. parkeri, R. bellii, R. rhipicephali, R. amblyommii and R. felis) were used for IFA. Ticks from each capybara were collected for posterior taxonomic identification. A total of 19 (61.3%) samples reacted to at least one of tested species. Seropositivity was found in 14 (45.2%), 12 (38.7%), 5 (16.1%), 4 (12.9%), 3 (9.7%) and 3 (9.7%) animals for R. rickettsii, R. bellii, R. parkeri, R. amblyommii, R. felis and R. rhipicephali, respectively. Two captive capybaras presented suggestive titers of R. rickettsii infection and one sample showed homologous reaction to R. parkeri. Only one free-ranging capybara presented evidence R. bellii infection. Ticks collected on capybaras were identified as Amblyomma dubitatum e Amblyomma sp. Results evidenced the rickettsial circulation in the area, suggesting a potential role of capybaras on bacterial life cycle.

Serologic and molecular diagnostic and bioassay in mice for detection of Toxoplasma gondii in free ranges chickens from Pantanal of Mato Grosso do Sul

The aim of this study was to investigate the occurrence of Toxoplasma gondii and compare the results obtained in the Modified Agglutination Test (MAT), Polimerase Chain Reaction (PCR) and bioassay in mice. In order to accomplish this, 40 free-range chickens from eight farms in neighboring areas to the Pantanal in Nhecolândia, Mato Grosso do Sul, were euthanized and blood samples, brain and heart were collected. The occurrence of anti-T. gondii antibodies found in chickens was 67.5% (27 samples), considering as a cutoff point the dilution 1:5. Among the samples analyzed, 7 (25.9%) were positive in the dilution 1:5, 3 (11.1%) in 1:10, 2 (7.4%) in 1:20, 3 (11.1%) in 1:320, 1 ( 3.7%) in 1:640, 3 (11.1%) in 1:1280, 2 (7.4%) in 1:2560, 4 (14.8%) in 1:5120 and 2 (7.4%) in 1:10.240. From the mixture of tissue samples (brain and heart) from the chickens analyzed, 16 (40%) presented electrophoretic bands compatible with T. gondii by PCR (gene B1). In the comparison of techniques, 59.26% positivity in PCR was revealed among animals that were seropositive in MAT (cutoff 1:5). From 141 inoculated mice, six (4.44%) died of acute toxoplasmosis between 15 and 23 days after inoculation. Surviving mice were sacrificed at 74 days after inoculation, and a total of 28 cysts were found in the brains of 10 distinct groups. From the seropositive hens, 27 bioassays were performed and 11 (40.7%) isolates were obtained. A greater number of isolations happened in mice that were inoculated with tissues from chickens that had high titers for anti-T. gondii antibodies. Chronic infection in mice was observed in nine groups (33.3%) from five different properties. Among the surviving mice, 25.6% were positive for T. gondii in MAT (1:25). From mice positive in PCR, 87.5% were also positive in MAT. Among the PCR-negative mice, 5.2% were positive for T. gondii in MAT. It can be concluded through this study that the occurrence of infecton by T. gondii in the rural properties studied was high, that PCR directed to gene B1 does not confirm the viability of the parasite, but it can be used as a screening method for the selection of chickens infected by T. gondii, that the animals with titer greater than 10 must be prioritized for the selection of animals for bioassay, since for them, the chances of isolating the parasite are greater and that seroconversion in experimentally infected mice is not a good indicator for isolating the agent.

Molecular detection of Neorickettsia risticii in Brazilian free-tailed bats (Tadarida brasiliensis) from Buenos Aires , Argentina

Neorickettsia risticii is the causative agent of Potomac Horse Fever, a severe febrile disease affecting horses, transmitted by trematodes species with a complex life cycle. A total of 30 insectivorous bats (Brazilian free-tailed bat Tadarida brasiliensis) were analyzed by PCR for presence of genus Anaplasma, Ehrlichia, Neorickettsia and Rickettsia. Three samples showed positive reactions for genus Anaplasma, Ehrlichia and Neorickettsia, and the sequences were 99.67% identical to Neorickettsia risticii. The role of bats in the life cycle of N. risticii has yet to be elucidated; however bats may be reservoirs for this bacterium. To our knowledge, this is the first evidence of N. risticii in Argentina.

Porcine follicular fluid concentration of free insulin-like growth factor-I collected from different diameter ovarian follicles

The study aimed to quantify the concentrations of free IGF-I in serum and fluid of ovarian follicles in pre-pubertal gilts and describe the ovarian morphology by measuring the size of the ovaries and counting the number of surface follicles. Ovaries (n=1,000) from pre-pubertal gilts were obtained immediately after slaughter. A total of 10 samplings were performed, with ovaries obtained from 50 females for each collection. The follicles situated on the surface of each ovary were classified as small (SFs, 2 to 5mm in diameter) or large (LFs 6 to 10mm in diameter) and the follicular fluid was obtained by follicle aspiration. The collection of serum samples was performed after the gilts exsanguination using sterile tubes. From the pool of serum and follicular fluid obtained from 50 females, the concentration of free IGF-I was determined in each sample using an enzyme immunoassay kit (ELISA). The description of ovarian morphometry was performed in 100 ovaries from randomly selected gilts. The larger and smaller lengths of ovaries were measured, and the total number of SFs and LFs present on the surface of each ovary were also counted. The IGF-I concentration was greater (P<0.05) in LFs (170.92±88.29 ng/mL) compared with SFs (67.39±49.90ng/mL) and serum (73.48±34.63ng/mL). The largest and smallest length of the ovaries was 26.0±3.0 and 19.0mm ±2.0mm, respectively. The number of SFs (70.86±25.76) was greater (P<0.01) than LFs (6.54±5.26). The study concluded that LFs present greater levels of IGF-I when compared with SFs and blood, which is related to increased activity of the LFs and its differentiation to ovulation. In addition, ovaries of pre-pubertal gilts have a higher number of SFs compared to LFs. Therefore, our study demonstrated unique data regarding the physiological concentration of free IGF-I in ovarian follicles, that can be used in future research to evaluate the addition of this hormone in the in vitro production media of porcine embryos with the goal to improve the technique efficiency.

Serosurvey of Leptospirainterrogans, Brucellaabortus and Chlamydophilaabortus infection in free-ranging giant anteaters (Myrmecophaga tridactyla) from Brazil

Abstract:A serological survey for antibodies against Leptospira interrogans, Brucella abortus, and Chlamydophila abortus was conducted in 21 clinically healthy, free-ranging giant ant- eaters (Myrmecophaga tridactyla) from Parque Nacional das Emas (Goiás State, Brazil; n=6), Parque Nacional da Serra da Canastra (Minas Gerais State, Brazil; n=9), and RPPN SESC Pantanal (Mato Grosso State, Brazil; n=6) between July 2001 and September 2006. Sera were screened for antibodies against 22 serovars of Leptospira interrogans with a microscopic agglutination test. Twelve tested positive for L. interrogansserovars sentot (n=5 in PN Emas, n=2 in PN Serra da Canastra), butembo (n=2 in PN Serra da Canastra), autumnalis, bataviae, and shermani/icterohaemorrhagiae(n=1 each in SESC Pantanal)One adult female tested positive for B. abortus with the buffered plate antigen test. All sera were negative for C. abortususing the complement fixation text. This is the first report of pathogens that may interfere with the reproduction and population dynamics of free-ranging giant anteaters.

Occurrence of antibodies against Leptospira spp. In free-ranging wild canids from the Brazilian savanna

Abstract: The Brazilian savanna, also known as Cerrado, is one of the world's richest and most ecologically invaluable tropical savanna regions. There are few studies in Brazil about the diseases that affect the wild canids of this biome, which may be harmful to wildlife populations and public health. The aim of this study was to evaluate the occurrence of antibodies against Leptospira spp. in three Cerrado wild canids species using the microscopic agglutination test (MAT). Serum samples were tested from 19 crab-eating foxes (Cerdocyon thous), 14 maned wolves (Chrysocyon brachyurus), and seven hoary foxes (Lycalopex vetulus), all free-ranging animals found in the municipalities of Araguari and Uberlândia, Minas Gerais State, and Cumari, Goiás State, Brazil. Fourteen (35%) of these samples were seropositive. The most frequent serovars detected in the samples were Copenhageni and Hardjo, but reactions to the serovars Autumnalis, Grippotyphosa, Hebdomadis, Wolffi, and Icterohaemorrhagiae also occurred. Notwithstanding other reported results, this study is the first to report the presence of antibodies against Leptospira spp. in L. vetulus. The three species of wild canids examined may act as potential hosts for several serovars of leptospira in Brazil's savanna environment.

Parâmetros reprodutivos e produtivos em vacas leiteiras de manejo free stall

Resumo Avaliou-se parâmetros reprodutivos e produtivos em vacas da raça Holandês-PB no pós-parto imediato, manejadas em free stall . Utilizou-se 51 vacas entre primíparas e pluríparas. Os valores obtidos foram: escore de condição corporal ao parto 3,47±0,4; intervalos do parto à primeira ovulação 5,89±3,4 semanas; ao primeiro serviço 112,5±57,0 dias; a taxa de gestação ao primeiro serviço foi 43,6% e no período experimental 76,4%, não sendo observada diferença para ordens de parto (P>0,05). A produção de leite acumulada à concepção, produção diária leite até a concepção e produção de leite ajustado para 305 foi respectivamente, 3.335,6±1.488,4; 25,8±5,4 e 7.424,0±1.877,8 litros. Conclui-se que no manejo de Free stall , a detecção de estro, foi o principal fator limitante para alcançar melhor eficiência reprodutiva.

EFFECTS OF PLANTING DATE AND SPATIAL ARRANGEMENT ON COMMON BEAN (Phaseolus vulgaris) YIELD UNDER WEED-FREE AND WEEDY CONDITIONS

ABSTRACTTo evaluate the effect of planting date and spatial pattern on common bean yield under weed-free and weed-infested conditions, an experiment was conducted in Kelachay, Northern Iran, in 2013. The experimental design was a randomized complete block in a factorial arrangement with three replicates. Factors were planting date (10 August and 20 August), spatial pattern (square and rectangular planting pattern, with a planting distance of 30 x 30 cm and 45 x 20 cm, respectively), and weed management regime (weed-free and weedy conditions, weeded and not weeded throughout the growing season, respectively). Results showed that the main effect of planting date was significant only for pod number per plant and seed number per pod. At the same time, pod number per plant, seed number per pod, pod length, and grain yield were influenced significantly by spatial pattern. Results of ANOVA have also indicated that all traits, except pod length, were influenced significantly by weed-management regimes. Moreover, effect of planting date and spatial pattern were nonsignificant for weed dry weight. Mean comparison has expressed a significant increment in seed yield for square planting arrangement (1,055 kg ha-1) over rectangular (971 kg ha-1). Weeding has also presented an overall 12% and 8% improvement in grain and pod yield over control (weedy check), respectively. Based on the results of this study, weed control, as well as square planting pattern, are recommended for obtaining the highest seed yield in common bean.

Nonspecific blockade of vascular free radical signals by methylated arginine analogues

Methylated arginine analogues are often used as probes of the effect of nitric oxide; however, their specificity is unclear and seems to be frequently overestimated. This study analyzed the effects of NG-methyl-L-arginine (L-NMMA) on the endothelium-dependent release of vascular superoxide radicals triggered by increased flow. Plasma ascorbyl radical signals measured by direct electron paramagnetic resonance spectroscopy in 25 rabbits increased by 3.8 ± 0.7 nmol/l vs baseline (28.7 ± 1.4 nmol/l, P<0.001) in response to papaverine-induced flow increases of 121 ± 12%. In contrast, after similar papaverine-induced flow increases simultaneously with L-NMMA infusions, ascorbyl levels were not significantly changed compared to baseline. Similar results were obtained in isolated rabbit aortas perfused ex vivo with the spin trap a-phenyl-N-tert-butylnitrone (N = 22). However, in both preparations, this complete blockade was not reversed by co-infusion of excess L-arginine and was also obtained by N-methyl-D-arginine, thus indicating that it is not related to nitric oxide synthase. L-arginine alone was ineffective, as previously demonstrated for NG-methyl-L-arginine ester (L-NAME). In vitro, neither L-arginine nor its analogues scavenged superoxide radicals. This nonspecific activity of methylated arginine analogues underscores the need for careful controls in order to assess nitric oxide effects, particularly those related to interactions with active oxygen species.

Antioxidant and free radical scavenging effects in extracts of the medicinal herb Achyrocline satureioides (Lam.) DC. ("marcela")

Achyrocline satureioides (Lam.) DC. (Compositae) is a medicinal herb used in Argentina, Uruguay, Brazil and Paraguay for its choleretic, antispasmodic and hepatoprotective properties. The presence of the flavonoid quercetin and its derivatives, and of different phenolic acids such as caffeic, chlorogenic and isochlorogenic acids in the aerial parts of this plant has led us to study the antioxidant activity of its extracts using different bioassays. The inhibition of luminol-enhanced chemiluminescence by the aqueous and methanolic extracts was used to show that their total reactive antioxidant potential index (TRAP; in µM Trolox equivalents) was 91.0 ± 15.4 and 128.1 ± 20.1 µM, respectively, while the total antioxidant reactivity index (TAR) was calculated to be 1537 ± 148 and 1910 ± 171 µM. Only the methanolic extract was capable of reducing iron (II)-dependent DNA damage. Lipid peroxidation was assessed by two different methods. The aqueous extract reduced hydroperoxide-initiated chemiluminescence in rat liver homogenates at all concentrations in a dose-dependent manner, with a calculated IC50 = 225 µg/ml, while the methanolic extract was only effective at higher concentrations (100 and 1000 µg/ml). Both aqueous and methanolic extracts were capable of reducing the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates, with an IC50 >1000 µg/ml. The results obtained suggest that the extracts of A. satureioides possess significant free radical scavenging and antioxidant activity in vitro, a fact that should encourage future in vivo studies.

Differential in vitro pathogenicity of predatory fungi of the genus Monacrosporium for phytonematodes, free-living nematodes and parasitic nematodes of cattle

In vitro tests were carried out on the pathogenicity of nine isolates of the predatory fungi of the genus Monacrosporium (5 M. sinense isolates, 3 M. appendiculatum and 1 M. thaumasium isolate) for a phytonematode (second stage juveniles from Meloidogyne incognita, race 3), a free-living nematode (Panagrellus spp), and two gastrointestinal parasitic nematodes of cattle (infective larvae of Cooperia punctata and Haemonchus placei). A suspension containing 2,000 nematodes from each species was added to Petri dishes containing fungi and grown on 2% water-agar medium at 25oC in the dark for up to 7 days. The dishes were examined every other day for 7 days and predation-free nematodes were counted. The results showed that the free-living nematodes, Panagrellus spp, were the most susceptible (P<0.05), followed by the phytonematode M. incognita, while the controls were ³98.5% viable. However, a variable susceptibility of the nematodes to different fungi was observed. This indicates that the use of predatory fungi for the environmental control of nematodes will be limited by the multiplicity of nematodes in the environment and their differential susceptibility to fungal isolates of the same genus.

Pancreatic nitric oxide and oxygen free radicals in the early stages of streptozotocin-induced diabetes mellitus in the rat

The objective of the present study was to explore the regulatory mechanisms of free radicals during streptozotocin (STZ)-induced pancreatic damage, which may involve nitric oxide (NO) production as a modulator of cellular oxidative stress. Removal of oxygen species by incubating pancreatic tissues in the presence of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD) (1 U/ml) produced a decrease in nitrite levels (42%) and NO synthase (NOS) activity (50%) in diabetic but not in control samples. When NO production was blocked by N G-monomethyl-L-arginine (L-NMMA) (600 µM), SOD activity increased (15.21 ± 1.23 vs 24.40 ± 2.01 U/mg dry weight). The increase was abolished when the NO donor, spermine nonoate, was added to the incubating medium (13.2 ± 1.32). Lipid peroxidation was lower in diabetic tissues when PEG-SOD was added (0.40 ± 0.02 vs 0.20 ± 0.03 nmol/mg protein), and when L-NMMA blocked NOS activity in the incubating medium (0.28 ± 0.05); spermine nonoate (100 µM) abolished the decrease in lipoperoxide level (0.70 ± 0.02). We conclude that removal of oxygen species produces a decrease in pancreatic NO and NOS levels in STZ-treated rats. Moreover, inhibition of NOS activity produces an increase in SOD activity and a decrease in lipoperoxidation in diabetic pancreatic tissues. Oxidative stress and NO pathway are related and seem to modulate each other in acute STZ-induced diabetic pancreas in the rat.