Universidade Federal de Roraima (UFRR)
Recent publications
The ongoing COVID-19 pandemic caused a significant loss of human lives and a worldwide decline in quality of life. Treatment of COVID-19 patients is challenging, and specific treatments to reduce COVID-19 aggravation and mortality are still necessary. Here, we describe the discovery of a novel class of epiandrosterone steroidal compounds with cationic amphiphilic properties that present antiviral activity against SARS-CoV-2 in the low micromolar range. Compounds were identified in screening campaigns using a cytopathic effect-based assay in Vero CCL81 cells, followed by hit compound validation and characterization. Compounds LNB167 and LNB169 were selected due to their ability to reduce the levels of infectious viral progeny and viral RNA levels in Vero CCL81, HEK293, and HuH7.5 cell lines. Mechanistic studies in Vero CCL81 cells indicated that LNB167 and LNB169 inhibited the initial phase of viral replication through mechanisms involving modulation of membrane lipids and cholesterol in host cells. Selection of viral variants resistant to steroidal compound treatment revealed single mutations on transmembrane, lipid membrane-interacting Spike and Envelope proteins. Finally, in vivo testing using the hACE2 transgenic mouse model indicated that SARS-CoV-2 infection could not be ameliorated by LNB167 treatment. We conclude that anti-SARS-CoV-2 activities of steroidal compounds LNB167 and LNB169 are likely host-targeted, consistent with the properties of cationic amphiphilic compounds that modulate host cell lipid biology. Although effective in vitro, protective effects were cell-type specific and did not translate to protection in vivo, indicating that subversion of lipid membrane physiology is an important, yet complex mechanism involved in SARS-CoV-2 replication and pathogenesis.
There are many claims that gamification (i.e., using game elements outside games) impact decreases over time (i.e., the novelty effect). Most studies analyzing this effect focused on extrinsic game elements, while fictional and collaborative competition have been recently recommended. Additionally, to the best of our knowledge, no long-term research has been carried out with STEM learners from introductory programming courses (CS1), a context that demands encouraging practice and mitigating motivation throughout the semester. Therefore, the main goal of this work is to better understand how the impact of a gamification design, featuring fictional and competitive-collaborative elements, changes over a 14-week period of time, when applied to CS1 courses taken by STEM students (N = 756). In an ecological setting, we followed a 2x7 quasi-experimental design, where Brazilian STEM students completed assignments in either a gamified or non-gamified version of the same system, which provided the measures (number of attempts, usage time, and system access) to assess user behavior at seven points in time. Results indicate changes in gamification’s impact that appear to follow a U-shaped pattern. Supporting the novelty effect, the gamification’s effect started to decrease after four weeks, decrease that lasted between two to six weeks. Interestingly, the gamification’s impact shifted to an uptrend between six and 10 weeks after the start of the intervention, partially recovering its contribution naturally. Thus, we found empirical evidence supporting that gamification likely suffers from the novelty effect, but also benefits from the familiarization effect, which contributes to an overall positive impact on students. These findings may provide some guidelines to inform practitioners about how long the initial contributions of gamification last, and how long they take to recover after some reduction in benefits. It can also help researchers to realize when to apply/evaluate interventions that use gamification by taking into consideration the novelty effect and, thereby, better understand the real impact of gamification on students’ behavior in the long run.
In Smart Cities (SC), the efficient management of services such as health, transport, public safety, and especially the electricity ensures the welfare of citizens. In recent years, the insertion of renewable sources (RSs) (e.g., solar and wind) in the power grid (PG) of SCs has contributed to meeting the electricity needs of the various consumer units. However, the large-scale integration of these RSs can fatigue the assets, leading to their premature aging and, consequently, compromising the quality of electricity supply. To overcome these challenges, the implementation of Neighboring Energy Storage Communities (NESCs) employing demand response (DR) strategies along with efficient coordination of storage batteries (SBs) could be a promising alternative. In this sense, the present work proposes a mixed-integer linear programming (MILP) model to efficiently manage SBs and the set of household appliances, including charging electric vehicles (EVs), in an NESC provided solely by PG. The proposed model aims to minimize: the total costs related to energy consumption, the peak rebound effect on the total consumption profile, energy wastage through load factor (LF) improvement, and the deep discharges in the SBs during their daily operational cycle. Operational constraints related to the home appliances, such as average usage time, the number of times that the appliance is used daily, etc., are taking into account. The EV state-of-charge (SOC), EV charging rate limits, and initial and final SOC of the SBs, are also considered. A Monte Carlo Algorithm (MCA) is used to simulate the habitual consumption patterns of each customer. The proposed model was implemented in AMPL and solved using CPLEX. The performance of this proposed model is evaluated considering two NESCs differentiated by the number of consumer communities. A first NESC (small-scale) is analyzed considering only two consumer communities. In this NESC, two case studies (Case 1 and 2) are discussed. Next, the second NESC (large-scale) that considers 14 consumer communities is analyzed for the most complete case study (Case 2). Within each NESC, consumer communities are differentiated by the household income and the types of SBs (individual and shared) that support each community. The results corroborate the applicability of the MILP model to real case studies on a diverse scale, guaranteeing the efficient use of PG at the same time that each SB seeks the most optimized operation.
Triplocania Roesler, 1940 has a high rate of endemism per country, with only five species out of a total of 118 described species, occurring in more than one country. Brazil is the second most diverse country in terms of Triplocania species, with 34 species recorded. In this paper, Triplocania furcatoides González-Obando, Carrejo-Gironza & García Aldrete, 2017 was recorded for Brazil and new records of Triplocania furcata New, 1972 made for four Brazilian states (Amazonas, Pará, Roraima and Tocantins), thus decreasing Wallace shortfall of these two species.
The purpose of this study was to evaluate the inclusion of cardanol in the diet of quails on productive performance, egg quality, reproductive performance, and progeny performance. A total of three hundred European quail breeders of 32 weeks of age, with average body weights of 305.98 g, were housed in laying cages in groups (4 females and 1 male), following a distribution in a completely randomized design with 5 treatments and 6 replications of 10 quails, being the experimental unit constituted by the set of two cages. The treatments consisted of diets with 0, 0.25, 0.50, 0.75, and 1.00% of cardanol. There was reduction in the performance of the quail with the inclusion of 1.00% of cardanol in the diet when compared to the control treatment, while egg weight and egg mass were lower in the treatments with 0.75 and 1.00% of cardanol, respectively. It was observed that there was decrease in the specific gravity, and increase in color and TBARS value of the yolk in all treatments with cardanol. The inclusion of 0.50% of cardanol decreased the percentage of albumen, and increased the percentage of yolk, while the shell thickness decreased with 0.75%. The weight of the incubated eggs and the chick weight at hatching were lower in the treatments with 0.75 and 1.00% of cardanol. In the evaluation of the progeny performance, it was found that the weight at 7 days of age of chicks from breeders fed the diet containing 1.00% of cardanol was decreased when compared to the chicks from breeders fed the control diet. It was concluded that the inclusion of cardanol did not present benefits to the quail breeders.
A crise sanitária provocada pela pandemia do COVID-19 exigiu medidas de distanciamento social, ampliando o uso da tecnologia digital, em distintos setores. Na educação, tal tecnologia tornou-se ferramenta essencial, com a adoção do ensino remoto. Nesse contexto, discute-se o Estágio Supervisionado (ES), na licenciatura em Matemática, em tempos de pandemia, em duas universidades públicas brasileiras, a Universidade Federal de Roraima (UFRR) e a Universidade Estadual de Goiás (UEG), a partir da seguinte questão investigativa: de que modo as propostas de ES dos cursos de licenciatura em Matemática, das referidas Instituições, foram adaptadas ao ensino remoto e as possíveis implicações na formação do futuro professor de Matemática? Para respondê-la, utilizou-se metodologia de natureza qualitativa, do tipo estudo de caso, com base na análise dos relatórios de Estágio elaborados pelos licenciandos, em 2020 e 2021, e reflexões acerca das práticas formativas adotadas pelas professoras formadoras no desenvolvimento das atividades que viabilizaram a execução do Estágio. Como resultados, destaca-se que as adequações das atividades de Estágio ao ensino remoto foram positivas, visto que os licenciandos ressaltam como importantes as experiências de ensino vivenciadas por tecnologias digitais. Com isso, evidenciaram maior tempo dedicado ao planejamento das aulas e dos materiais didáticos, bem como dificuldades em obter feedback dos alunos e realizar processos avaliativos de forma virtual.
There is a concern that environmental threats that result in local biodiversity loss compromise traditional peoples’ livelihoods and their traditional ecological knowledge (TEK). Nonetheless, studies usually only analyze how people’s characteristics influence TEK. Here, we investigated both: how the personal characteristics of local specialists (forest experience, gender, and origin) and environmental threats (deforestation, mining, and fires) influence some components of TEK associated with forests. From 2015 to 2019, we conducted free-listing interviews with 208 specialists from 27 communities in and near 10 protected areas (PAs) in Brazilian Amazonia. We recorded forest trees and palms that the specialists mentioned as used, managed, and traded. Plant knowledge was variable, since 44% of the 795 ethnospecies were mentioned only once. Using Mixed-Effects Models, we identified that people with longer forest experience and men tended to cite more used and traded ethnospecies. Women knew more about human food, while men knew more about construction and animal food. Specialists with greater forest experience knew more about protective management and planting. Specialists living in communities influenced by mining cited fewer used ethnospecies, and those in more deforested communities cited proportionally more planting. Environmental threats had smaller effects on TEK than personal characteristics. The components of TEK that we assessed highlight the forest’s great utility and the importance of management of PAs to maintain biodiversity and traditional people’s livelihoods. The communities’ stocks of TEK persisted in the face of environmental threats to PAs, highlighting the resistance of traditional peoples in the face of adversities. This quantitative approach did not show the trends that are generally imagined, i.e., loss of forest TEK, but demonstrates that if we want to change the Amazonian development model to keep the forest standing, knowledge exists and resists.
This is the third year of the SARS-CoV-2 pandemic, and yet most children remain unvaccinated. COVID-19 in children manifests as mostly mild or asymptomatic, however high viral titers and strong cellular and humoral responses are observed upon acute infection. It is still unclear how long these responses persist, and if they can protect from re-infection and/or disease severity. Here, we analyzed immune memory responses in a cohort of children and adults with COVID-19. Important differences between children and adults are evident in kinetics and profile of memory responses. Children develop early N-specific cytotoxic T cell responses, that rapidly expand and dominate their immune memory to the virus. Children’s anti-N, but not anti-S, antibody titers increase over time. Neutralization titers correlate with N-specific antibodies and CD8 ⁺ T cells. However, antibodies generated by infection do not efficiently cross-neutralize variants Gamma or Delta. Our results indicate that mechanisms that protect from disease severity are possibly different from those that protect from reinfection, bringing novel insights for pediatric vaccine design. They also underline the importance of vaccination in children, who remain at risk for COVID-19 despite having been previously infected.
This study evaluated cassava stems (CS) as support material and a potential co-substrate in dark fermentation. Pre-tests were carried out with cell immobilization in CS without hydrolysis and submitted to acid and steam hydrolysis. Subsequently, hydrogen production was evaluated in an anaerobic sequencing batch biofilm reactor inoculated with biomass immobilized in CS, using cassava starch wastewater as substrate (OLR of 11 and 15 gCarb L⁻¹d⁻¹). The reactor was run for 180 cycles with maximum volumetric hydrogen productivity and a yield of 1.48 LH2 L⁻¹d⁻¹ and 1.98 molH2 kg⁻¹Carb (OLR 15 gCarb L⁻¹d⁻¹). The carbohydrate conversion remained above 97% in both assays, with a predominance of the acetate-ethanol route. During the assays, the Food/Microorganisms ratio remained between 0.8 to 1.0 gCarb gTVSd⁻¹, promoting the biomass control in the reactor. The structural characterization of CS before and after fermentation indicates that the cellulose, hemicellulose, and lignin content in the stems were changed after hydrolysis and fermentation, confirming the material degradation. In addition, the hydrolysis increased the CS surface area and favored cell immobilization of hydrogen-producing microorganisms such as bacteria of the genus Clostridium and Hydrogenispora, demonstrating that CS can be an alternative support material and co-substrate to be explored in dark fermentation.
Fruticulture in the Amazonian Rainforest is one of the main causes of deforestation, biodiversity loss, and soil erosion. Fruticulture plays a key role in the soil traits and soil organic matter (SOM) compartments by altering the soil ecosystem. Our aim was to assess the influence of Forest-Fruticulture conversion on soil traits, and SOM fractions in Brazil's Legal Amazon. The experiment was carried out in field conditions using four land uses as main treatments: Bixa orellana, Theobroma grandiflorum, Paullinia cupana, and the Amazon Rainforest. The soil physicochemical traits were analyzed using samples that were collected from 0-5, 5-10, and 10-20 cm soil depth by using grids (10 × 10 m) with 36 sampling points. Our results showed that the Fruticulture promoted an increase in bulk density, GMD, aggregate diameter, soil porosity, gravimetric moisture, sand, clay, carbon associated with humic acid, and, the sum of bases (K + , Ca 2+ , and Mg 2+), while the Amazon Rainforest showed the highest values of silt, soil P content, SOC, p-SOC, m-SOC, carbon associated with fulvic acid, humine, and soil C stock. Overall, the fruticulture farming systems have negative effects on SOM compartments. The results of our study highlight the importance of considering fruticulture with endemic plant species by promoting soil fertility and soil aggregation.
The present research aimed to evaluate the shrimp waste meal (SWM) in the diet of European quails in the production phase. Firstly, a metabolism trial was carried out with 96 quails of 28 days of age distributed in an completely randomized design (CRD) with three treatments (reference diet and two test diets in which SWM replaced 20% and 40% of the reference diet) and four replications of eight birds. It was observed that the nutritional composition of SWM is within the variation found in the literature, differing only in the sodium content. There was no difference in apparent metabolizable energy (AME) and apparent corrected for nitrogen balance (AMEn) values. In the performance trial 200 quails of 28 weeks of age were distributed in a CRD with four treatments (0, 5, 10 and 15.0% of inclusion of SWM) and five replications of ten birds. There was reduction in the nitrogen metabolization coefficient (NMC) with the inclusion of 15% SWM. The feed intake, production and egg mass worsened with 15% inclusion, causing a linear reduction of these variables. The inclusion of SWM at all levels reduced the values of specific gravity and Hugh units, and the level 15% promoted reduction in shell percentage and shell thickness. No difference was observed on any of the economic variables. It was concluded that the AMEn of SWM is 2,377 kcal/kg DM and that the inclusion of SWM in the diet of quails in production can be up to 10%.
Psychotria viridis (Rubioideae: Rubiaceae), popularly known as chacrona, is commonly found as a shrub in the Amazon region and is well-known to produce psychoactive compounds, such as the N,N-dimethyltryptamine (DMT). Together with the liana Banisteropsis caapi, P. viridis is one of the main components of the Amerindian traditional, entheogenic beverage known as ayahuasca. In this work, we assembled and annotated the organellar genomes (ptDNA and mtDNA), presenting the first genomics resources for this species. The P. viridis ptDNA exhibits 154,106 bp, encoding all known ptDNA gene repertoire found in angiosperms. The Psychotria genus is a complex paraphyletic group, and according to phylogenomic analyses, P. viridis is nested in the Psychotrieae clade. Comparative ptDNA analyses indicate that most Rubiaceae plastomes present conserved ptDNA structures, often showing slight differences at the junction sites of the major four regions (LSC-IR-SSC). For the mitochondrion, assembly graph-based analysis supports a complex mtDNA organization, presenting at least two alternative and circular mitogenomes structures exhibiting two main repeats spanning 24 kb and 749 bp that may symmetrically isomerize the mitogenome into variable arrangements and isoforms. The circular mtDNA sequences (615,370 and 570,344 bp) encode almost all plant mitochondrial genes (except for the ccmC, rps7, rps10, rps14, rps19, rpl2 and rpl16 that appears as pseudogenes, and the absent genes sdh3, rps2, rsp4, rsp8, rps11, rpl6, and rpl10), showing slight variations related to exclusive regions, ptDNA integration, and relics of previous events of LTR-RT integration. The detection of two mitogenomes haplotypes is evidence of How to cite this article Varani AM, Silva SR, Lopes S, Barbosa JBF, Oliveira D, Corrêa MA, Moraes AP, Miranda VFO, Prosdocimi F. 2022. The complete organellar genomes of the entheogenic plant Psychotria viridis (Rubiaceae), a main component of the ayahuasca brew. heteroplasmy as observed by the complex organization of the mitochondrial genome using graph-based analysis. Taken together, these results elicit the primary insights into the genome biology and evolutionary history of Psychotria viridis and may be used to aid strategies for conservation of this sacred, entheogenic species.
Tomando os meios de comunicação digitais não como instrumentos de organização das dinâmicas cotidianas, mas como parte da estruturação do social (GOMES, 2017), esta pesquisa pretende pensar a constituição dos Territórios Midiáticos nas práticas comunicacionais do Movimento Indígena. Para tanto, valendo-se da midiatização como conceito-chave, trabalhamos a definição do que chamamos de Territórios Midiáticos através de duas frentes: 1) como conjunto de representações sobre o território (RAFFESTIN, 1993); e 2) como espaço/bios midiático (SODRÉ, 2002). O estudo pautase na realização de uma análise diacrônica dos processos de midiatização do território nas práticas de etnocomunicação do Conselho Indígena de Roraima a fim de acompanhar o movimento de instalação dos processos de midiatização do território e/ou dos chamados Territórios Midiáticos.
Phyllomedusa bicolor (Phyllomedusidae), popularly known as the kambô in Brazil, is a tree frog that is widely distributed in South American countries and is known for producing a skin secretion that is rich in bioactive peptides, which are often used in indigenous rituals. The biological effects of the skin secretion were observed in the first studies with indigenous communities. Over the last six decades, researchers have been studying the chemical composition in detail, as well as the potential pharmacological applications of its constituents. For this reason, indigenous communities and health agents fear the misuse of the kambô, or the inappropriate use of the species, which can result in health complications or even death of users. This article seeks to provide a transdisciplinary review that integrates knowledge regarding the biology of P. bicolor, ethnoknowledge about the ritual of the kambô, and the chemistry and pharmacology of the skin secretion of this species, in addition to medical aspects of the indiscriminate use of the kambô. Furthermore, this review seeks to shed light on perspectives on the future of research related to the kambô.
Lakes are features found in Brazil’s northern region, commonly formed in sandy-clay layers of the Plio-Pleistocene, in a setting of the extensive flat surface, and under a high precipitation rate. Our goal in this work is to understand the sediment transport dynamic and its relation to the hydrological behavior of the regional lacustrine system. Two lakes were selected, Lago do Italiano (LIT) and Lago do Bicho (LB), situated in the municipality of Bonfim in the state of Roraima, Brazil. The lakes differ in hydrological regime, depth, and vegetation. The methodology involved bibliographical and remote sensor data and field surveys followed by laboratory processing. The results revealed that the lakes are composed of sandy materials, with layers what reach 95% of sand. The grains is medium to fine texture, with morphology angular (0 a 50%) and subangular (18% a 43%) grains, disposed at different depths. The grains’ morphology suggests that their sediment provider source is near and, at the same time, indicates a low energy environment. Concerning the mineralogical attributes, the sediments are of a quartzose nature, which permits their correlation with the arenites of the Boa Vista Formation, a sub-cropping unit. The sediment input is controlled by the seasonal oscillation of the groundwater level and inundation pulses that reach the fluviolacustrine plain of the Tacutu River in which the lakes are inserted.
Copaifera L. is a woody legume genus with 42 species that produce valuable terpenoid oleoresins used in medicine and industrial activities. Copaifera belongs to the Detarieae (Detarioideae) and is part of a clade together with five other genera. We describe the seedling morphology of Copaifera pubiflora Benth. based on plant architectural analysis to shed light on its post-seminal shoot development. Seeds of this species were collected from a wild population in Roraima State, Brazil. Seedlings of C. pubiflora have preformed shoots with determinate and rhythmic growth. Each growth unit has two reduced leaf scales that correspond to a pair of prophylls followed by two or three scale-like stipules and one distal eophyll. Besides, C. pubiflora has a monochasial sympodial branching with delayed branches. Current evidence indicates that most Copaifera species, including C. pubiflora, have phanerocotylar, epigeal, reserve seedlings with a cataphyll-free epicotyl and scale-like structures on the first internode after the epicotyledonary axis. Based on the available data, a comprehensive view of Copaifera seedlings from both the Old and New Worlds is also presented.
This paper focuses on the (ought-to-be) deontic, which is analyzed from the concepts of obligation discussed in Castañeda (1970), Feldman (1986) and Hacquard (2006, 2010). From co-occurrence tests of an ought-to-be modal with other elements in the CP layer – in particular, with the wh-phrase por que ( why ) and with adverbial elements, it was found that ought-to-be is interpreted between the high projections IntP and ModP. It was also shown that an ought-to-be can be used in an utterance with or without a specific addressee and that this difference reflects in the syntax. The proposal is to extend the analysis by Portner, Pak and Zanuttini (2019), developed for Korean speech style particles, to the ought-to-be deontic, postulating that this deontic, when used with a specific addressee, integrates a structure in which the cP category is projected, which allows features that express the speaker-addressee relation, such as status, to be checked. Consequently, this modal is restricted to the matrix domain. When, however, it appears in an utterance without a specific addressee, it integrates a structure without the projection of cP, since it does not refer to the speaker-addressee relationship. In this case, it can appear in both the matrix and embedded domains. ought-to-be deontic modality; speaker-addressee relationship; cP category
Objetivos Traçar o perfil fenotípico dos doadores do grupo sanguíneo O, avaliando a presença dos antígenos D, C, “c”, E, “e”, K, “k”, Kpa, Kpb, Fya, Fyb, Jka, Jkb, M, N, S, “s”, Lea, Leb, Lua, Lub e P1 identificando o perfil fenotípico dos doadores de sangue do serviço de hemoterapia. Material e métodos Estudo retrospectivo, realizado com 1.248 doadores de sangue do Hemocentro de Roraima que doaram sangue no período de outubro de 2021 a março de 2022, com algum grau de fenotipagem. Fenotipagens Rh/K foram realizadas em microplaca ou gelcentrifugação. Os dados foram retirados do sistema Hemovida e analisados através do Qui-Quadrado de aderência, com p0,005, pelo software livre R Core Team (2021). Essa pesquisa foi aprovada pelo Comitê de Ética e Pesquisa pelo número 51447821.8.0000.5302. Resultados Dos 1248 doadores avaliados em relação aos antígenos do sistema Rh, D+: 81,73% (1020), D-: 18,27% (228), C+: 59,9% (747), E+: 31,19% (389), “c”+: 81,96% (1022), “e”+: 95,74% (1192). Em relação ao sistema Kell, K+: 3,53% (44), “k”+: 100% (710), Kpa+: 0,85% (6), Kpb+:99,72%(708). Em relação ao sistema Duffy, Fya+:66,86% (466), Fyb+: 64,13% (447). Em relação ao sistema Kidd, Jka+:75,21% (534), Jkb+: 67,84% (481). Em relação ao sistema MNS, M+: 83,21% (580), N+: 66,24% (461), S+: 47,2% (329), “s”+: 91,39% (637). Em relação ao sistema Lewis, Lea+:9,98% (51), Leb+: 68,88% (352). Em relação ao sistema Lutheran, Lua+: 6,1% (31), Lub+: 99,61% (352) e em relação ao sistema P1, P1+: 80,63% (412). Discussão Os antígenos encontrados com maior frequência foram “k”, Kpb, Lub, “e”e “s”respectivamente, “k”tem frequência igual a negros (100%), Kpb. “s”e “e”têm frequência similar aos caucasianos (100%; 93%; 98%), Lub tem alta frequência como em todas as populações do mundo (99,8%). Os antígenos com menor frequência encontrados foram Kpa, K, Lua, Lea e E respectivamente, Kpa e E tem frequência próxima a caucasianos (2%; 29%), K e Lua tem frequência próxima a negros (2%; 5%). Leatem frequência menor do que a encontrada em caucasianos e negros (22%; 23%). Todos os antígenos do sistema Rh tiveram frequências similares aos caucasianos. Leb a frequência encontrada é intermediária entre caucasianos e negros (72%, 55%). Fya tem similaridade com caucasianos (66%) e Fybtem frequência menor que em caucasianos (83%) e maior que em negros (23%). Jka e Jkb tem frequência aproximada com caucasianos (77%; 74%). M e N, a frequência encontrada foi próxima a de caucasianos (78%; 72%). Conclusão O antígeno mais frequente na população estudada foi “k”e o menos frequente foi Kpa. É necessário que os hemocentros tenham banco de dados de seus doadores em relação às fenotipagens para poder atender aos pacientes que necessitam receber bolsas fenotipadas como profilaxia contra aloimunização ou devido à presença de aloanticorpos ou autoanticorpos, melhorando a qualidade dos serviços hemoterápicos.
The use of sunflower cake (SC) in animal feed has been studied mainly due to the characteristics that are given to them, since this byproduct when incorporated in the feed can increase the economic viability and the nutritional value of the diet. The objective of this study was to evaluate the inclusion of sunflower cake in lightweight pullet diets and check their nutrient digestibility and metabolizable energy for several parameters, including diet, performance, body composition, nutrient retention, energy metabolism at the growth phase, performance of egg production, sexual maturity, and egg quality at the beginning of the laying phase. We distributed a total of 648 pullets in our study, which was a completely randomized design including six treatments with six replicates of 18 pullets each. The treatments included diets with 0, 5, 10, 15, 20, and 25% SC. Our study results concluded that pullets fed with diets containing SC showed a reduction (P<0.01) in nutrient digestibility and metabolizable energy compared to those fed with the control diet. Pullets fed with 25% SC showed an increase (P<0.01) in feed intake and feed conversion ratio. However, dietary inclusion of SC in pullet diets did not influence (P>0.05) their body composition, nutrient retention, energy metabolism, sexual maturity, egg-laying performance, and egg quality of laying hens between 18 and 35 weeks of their age. Therefore, up to 25% of SC could be included in the diet of lightweight laying pullets in the growth phase since it exhibited no residual effect on their productive performance at the beginning of the laying phase. Index terms: Egg quality; energy metabolism; Helianthus annuus; laying hens; laying performance.
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