171 resultados para Authoritative feeding


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This study investigates the presence and the localization of acid phosphatase and ATPase in the salivary glands of Rhipicephalus (Boophilus) microplus female ticks during feeding. Semi-engorged females showed a larger amount of acid phosphatase compared to those at beginning of feeding, localized mainly in the apical portion of the secretory cells, and in the basal labyrinth of the interstitial cells. Ultrastructural observations also demonstrated its presence in secretion granules and inside some nuclei of secretory cells at beginning of feeding. Acid phosphatase in a free form probably has a hemolymph and/or ribosomal origin and participates in salivary gland secretion control. ATPase was detected in basal membrane of all types of acini and/or in the cytoplasm of the secretory cells at both feeding stages. The enzyme activities found strongly suggests that cell death by apoptosis occurs during the degenerative process. © 2006 Elsevier Inc. All rights reserved.

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Larvae of Chrysomya albiceps (Wiedemann) and Chrysomya putoria (Wiedemann) were reared on liver tissues from a rabbit that had a malignant tumor in the thoracic cavity. Larval rearing of both blowfly species was conducted at ambient temperature. Larvae that fed on tissues from the rabbit with the tumor developed at significantly faster rates than those feeding on tissues from the control animal.

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Functional feeding habits of Chironomidae larvae (Insecta, Diptera) in a lotic system from Mid-western region of São Paulo State, Brazil were analyzed. Collectors were the dominant organisms, repre-sented by genera Chironomus, Fissimentum and Cryptochironomus, following by shredders and predators.

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In addition to providing nutrition and immunological protection, breast-feeding has positive effects on the development of the infant's oral cavity. The aim of the present study is to assess breast-feeding patterns and to analyze the influence of breast-feeding practices and maternal sociodemographic variables on the prevalence of non-nutritive sucking habits in a sample of Brazilian infants. This cross-sectional study was carried out in Southern Brazil. A random sample of 100 mothers of infants up to 12 months of age was interviewed during the National Vaccination Campaign Day. The prevalence and median duration of breast-feeding were assessed. Breast-feeding practice, the exposure factor, was categorized as exclusive breast-feeding, predominant breast-feeding, complementary breast-feeding, or weaning. Maternal sociodemographic variables included age, race, marital status, educational level, profession, and family income. The outcome investigated was the prevalence of sucking habits (pacifier use and thumb sucking). We used two-sample tests, the chi-square test and Fisher exact test0 for statistical analyses of the data. The study revealed that 75% of infants were being breast-fed. Pacifier use and thumb sucking were common in 55%. Bottle-feeding was prevalent in 74% of infants. Breast-feeding was negatively correlated with pacifier use and thumb sucking (OR = 0.11; 95% CI: 0.03 to 0.4). Bottle-feeding was strongly associated with weaning (p = 0.0003). Among the sociodemographic variables, only marital status showed a statistical association with sucking habits (p = 0.04). These findings suggest that breast-feeding can prevent the occurrence of sucking habits. Although we could not evaluate causality assessment, malocclusion prevention seems to be yet one more reason for promoting breast-feeding practices.

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The objective of this study was to evaluate the feeding management of pacu juveniles (P. mesopotamicus) under different feeding rates and its relation with productive performance, body composition and hematological characteristics. A total of 300 fish with initial weight of 84.75±4.52 g were distributed in a completely randomized design composed of four treatments (100, 90, 80 and 70% of feed supply) and five repetitions. The amount of feed was stipulated according to the quantity supplied in the treatment until apparent satiation (100%) of the day before. The decrease in the feeding rate to 70% over satiation apparently improves the apparent feed conversion without harming performance, body composition or biochemical and hematological characteristics of pacu juveniles reared in net cages. © 2012 Sociedade Brasileira de Zootecnia.

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This study presents new information on feeding habits of Guiana dolphins, Sotalia guianensis, in south-eastern Brazil, together with new regression equations to evaluate the weight and length of fish from otoliths, showing an overview on the knowledge about this species-diet in this area. Eighteen stomach contents had been analysed and compared to 180 samples collected in another eight feeding studies. The analysed specimens were either incidentally caught in gillnets used in coastal waters by the fleet based in the Cananéia main harbour (25°00âS 47°55âW), south of São Paulo State, or found dead in inner waters of the Cananéia estuary between 2003 and 2009. Based on the index of relative importance analysis, the most important fish species were the banded croaker, Paralonchurus brasiliensis. Doryteuthis plei was the most representative cephalopod species. Stellifer rastrifer was the most important fish species observed in dolphins in inner estuarine waters and P. brasiliensis in recovered dolphins from coastal waters. Loliguncula brevis is the only cephalopod species reported from dolphins found in inner estuarine waters up to date. Doryteuthis plei was the most important cephalopod species observed in coastal dolphins. When considering other feeding studies, the most representative fish family in the diet of S. guianensis was Sciaenidae, which is mainly represented by demersal fishes. The main preys of S. guianensis are abundant in the studied areas, which may indicate an opportunistic feeding habit. The majority of them are not the most important target species by the commercial fishery in south-eastern Brazil. © 2012 Marine Biological Association of the United Kingdom.

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Parental effort may influence the fitness and survivorship of adult birds and their offspring from one breeding season to the next. Although much is known about parental feeding effort in tyrant flycatchers, many species remain understudied. In this study, I examined parental feeding effort of the White-headed Marsh-Tyrant (Awndinicola leucocephala) at a pond in southeastern Brazil. I conducted 10.3 hrs of observations from two locations: a high place with all view of the whole pond, that allowed me to observe flight distances of parents hunting for prey; and from near the nest to observe frequency of visits to the nest. The female marsh-tyrant flew farther while hunting prey and made more visits to the nest than did the male. The adults (mainly the female) provided a variety of terrestrial and aquatic arthropods to the nestlings. Additionally, parents removed fecal sacs from the nest and nestlings eliminated arthropod remains from the nest, the first records of nest sanitation activities by this species. Nonexclusive hypotheses that may explain the lower level of parental care provided by the male include: higher predation risk due its more conspicuous plumage, commitment of male to territory defense, and its selfish behavior influenced by indirect genotype fitness inherited by the offspring. © The Neotropical Ornithological Society.

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The intestinal epithelial cells of ticks are fundamental for their full feeding and reproductive success, besides being considered important sites for the development of pathogens. Rhipicephalus sanguineus ticks are known for their great medical and veterinary importance, and for this reason, the knowledge of their intestinal morphology may provide relevant subsidies for the control of these animals, either by direct acaricidal action over these cells or by the production of vaccines. Therefore, this study aimed to describe the midgut morphology of male and female R. sanguineus ticks in different feeding stages, by means of histological analysis. Significant differences were observed between the genders, and such alterations may refer mainly to the distinct demands for nutrients, much higher in females, which need to develop and carry out the egg-laying process. In general, the midgut is coated by a thin muscle layer and presents a pseudostratified epithelium, in which two basic types of cells can be observed, connected to a basal membrane - generative or stem and digestive cells. The latter was classified as follows: residual, deriving from the phase anterior to ecdysis; pinocytic, with vesicles containing liquid or pre-digested components of blood; phagocytic, with entire cells or remnants of nuclear material inside cytoplasmic vesicles; and mature, free in the lumen. Digestion is presumably intracellular and asynchronous and corresponds to a process which starts with the differentiation of generative cells into pinocytic digestive cells, which subsequently start to phagocytize intact blood cells and finally detach from the epithelium, being eliminated with feces. © 2012 Springer-Verlag Berlin Heidelberg.

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This study analyzed the histopathology of rabbit skin, previously immunized with SGE2, SGE4, and SGE6 gland extracts prepared from salivary glands of Rhipicephalus sanguineus female with 2, 4, and 6 days of feeding, at the region of the R. sanguineus female feeding lesion 2, 4, and 6 days after tick attachment. In this work, infestation-naïve New Zealand White rabbits were inoculated either with the extracts (test group (TG)) or with phosphate buffer and complete Freund's adjuvant mixture (control group 2 (CG2)). Each extract-inoculated- (TG and CG2) and non-inoculated (CG1) rabbit was subsequently infested with R. sanguineus. Skin biopsies were collected from the rabbit at the tick feeding lesion at 2, 4, and 6 days of feeding. Results revealed that rabbit immunization with gland extracts induced acquisition of resistance against this species. It should be stated that the SGE4 extract was the most effective in developing an immune-inflammatory response against ectoparasites, being this process characterized by the presence of an early and intense inflammatory cell infiltrate. On the other hand, SGE6 extract caused a later appearance of resistance with less infiltrate occurrence and intense edema at the feeding lesion site. As to the inflammatory process deriving from SGE2 extract inoculation, it was the less intense. It was concluded that immunization with different extracts from R. sanguineus female salivary glands did not change microscope features of the inflammatory process, although an earlier or more intense and later response, which was also dependent on the inoculate extract, was noticed. © 2012 Springer-Verlag Berlin Heidelberg.

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Nile tilapia fish were individually reared under similar light levels for 8 weeks under five colored light spectra (maximum wavelength absorbance): white (full light spectrum), blue (~452 nm), green (~516 nm), yellow (~520 nm) or red (~628 nm). The effects of light on feeding, latency to begin feeding, growth and feed conversion were measured during the last 4 weeks of the study (i.e., after acclimation). We found that red light stimulates feeding, as in humans, most likely by affecting central control centers, but the extra feeding is not converted into growth. © 2013 Volpato et al.

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Anuran larvae, which are otherwise simple in shape, typically have complex keratinized mouthparts (i.e. labial teeth and jaw sheaths) that allow them to graze upon surfaces. The diversity in these structures among species presumably reflects specializations that allow for maximal feeding efficiency on different types of food. However, we lack a general understanding of how these oral structures function during feeding. We used high-speed digital imaging (500 Hz) to observe tadpoles of six species from the anuran family Hylidae grazing on a standardized food-covered substrate. Tadpoles of these species vary in the number of labial tooth rows, belong to two different feeding guilds (benthic and nektonic), and inhabit ponds and streams. We confirmed that the labial teeth in these species serve two functions: anchoring the mouth to the substrate and raking material off of the substrate. In general, tadpoles with a larger maximum gape or those with fewer labial tooth rows opened and closed their mouths slower than tadpoles with smaller gape or more tooth rows. Nektonic feeding tadpoles released each of their tooth rows proportionally earlier in the gape cycle compared with benthic feeding tadpoles. Lastly, we found some support for the idea that deformation of the jaw sheaths during a feeding cycle is predictable based on tadpole feeding guild. Collectively, our data show that anatomical (e.g. number of labial teeth) and ecological features (e.g. feeding guild) of tadpoles significantly influence how tadpoles open and close their mouths during feeding. © 2013. Published by The Company of Biologists Ltd.

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This study investigated the protective effect of spray-dried açaí powder (AP) intake on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in male Wistar rats. After 4. weeks of DMH administrations, the groups were fed with standard diet, a diet containing 2.5% or 5.0% AP or a diet containing 0.2% N-acetylcysteine (NAC) for 10. weeks, using aberrant crypt foci (ACF) as the endpoint. Additionally, two groups were fed with standard diet or a diet containing 5.0% AP for 20. weeks, using colon tumors as the endpoint. In ACF assay, a reduction in the number of aberrant crypts (ACs) and ACF (1-3 AC) were observed in the groups fed with 5.0% AP (37% AC and 47% ACF inhibition, p=. 0.036) and 0.2% NAC (39% AC and 41% ACF inhibition, p=. 0.042). In tumor assay, a reduction in the number of invasive tumors (p<. 0.005) and tumor multiplicity (p=. 0.001) was observed in the group fed with 5.0% AP. Also, a reduction in tumor Ki-67 cell proliferation (p=. 0.003) and net growth index (p=. 0.001) was observed in the group fed with 5.0% AP. Therefore the findings of this study indicate that AP feeding may reduce the development of chemically-induced rat colon carcinogenesis. © 2013 Elsevier Ltd.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Breeder feed restriction may negatively affect broiler progeny immunity. Sources of trace minerals (TM) with higher bioavailability in breeder diets have been reported to enhance humoral and cellular immunity in broiler progeny. An experiment was conducted to examine the effects of breeder feeding programs and TM dietary sources on maternal antibody transfer and humoral immune response of progeny to a live vaccine against Newcastle disease virus (NDV). Cobb 500 breeders were fed according to 2 feed allocation programs, sigmoid late fast and sigmoid late slow, from 14 to 29 wk of age. From 56 to 62 wk of age, breeders were fed with either inorganic TM or an organic source (OTM) to replace 30% of Cu, Zn, and Mn. Progeny broilers were vaccinated intraocularly with La Sota NDV vaccine at 7 d of age. Blood samples were collected at hatching, 4, and 14 d postvaccination. Serum antibody levels against NDV were assessed by ELISA and cytokine expression by real time PCR. At hatching, late slow breeder progeny fed diets with 30% OTM had higher antibody titers as compared with progeny of breeders fed 100% inorganic TM. Similar results were observed 2 wk postvaccination. Breeder feeding programs and TM sources affected the expression level of IL-4 in NDV vaccinated broiler progeny. It was concluded that breeder feeding programs influenced humoral immune response to NDV vaccine in the broiler progeny, and 30% OTM may increase these responses. © 2013 Poultry Science Association, Inc.