ABSTRACT In this study, we evaluated how guanidinoacetic acid (GAA) addition in diets with various metabolizable energy (ME) contents affects the performance of broiler chickens. We also estimated the equivalence of GAA in ME. We distributed 1,280 one-day-old broilers in a completely randomized design with eight treatments, eight replicates, and twenty birds per experimental unit. Treatments were based on ME levels (2,775-2,875-2,975 kcal/kg; 2,850-2,950-3,050 kcal/kg; 2,925-3,025-3,125 kcal/kg; or 3,000-3,100-3,200 kcal/kg, from 1 to 7, 8 to 21, and 22 to 42 days of age) and the inclusion of GAA (0 or 600 mg/kg). Supplementation of GAA increased weight gain in broilers at an energy level of 2,908 kcal/kg and improved feed conversion ratio (FCR) at energy levels of 2,908 and 2,983 kcal/kg. There was a linear reduction in feed intake and an improvement in FCR of broilers with increasing levels of energy in diets, with and without GAA addition. Solving the equivalence equation, by applying each of the weighted average energy levels studied. indicates the GAA equivalence of 133, 103, 74, and 44 kcal/kg of diet. In conclusion, GAA supplementation improves broilers’ efficiency of energy use; the average ME equivalence of 600 mg/kg of GAA is 88.5 kcal/kg.

Abstract The objective of this work was to investigate the application of microwave vacuum drying (MWVD) as a fast drying method to produce salted-and-dried beef cuts. Moreover, aiming to reduce the sodium content in the meat product, the partial replacement of NaCl by KCl during the salting stage was also investigated. To this end, beef cuts were salted by immersion in one of three saline solutions before drying: Solution A- 100% NaCl; Solution B- 75% NaCl and 25% KCl; and (iii) Solution C- 50% NaCl and 50% KCl. The proposed MWVD method was compared with convective drying (CD) and vacuum drying (VD) in terms of drying kinetics as well as physicochemical and mechanical properties of obtained samples. The average drying times for the samples to reach water activity of 0.7 was more than 40 h for CD, 36 h for VD, and 0.45 h for MWVD. The salting with different solutions had no influence in these times. Moreover, the MWVD samples presented higher values of porosity and rehydration capacity. Thus, the results presented in this study have technological importance for the design of new industrial technologies to produce salted-and-dried meat, as charque and jerked beef, with lower sodium content.

ABSTRACT Presence of toxic compounds in marine coastal waters has increased exponentially since Industrial Revolution. In this way, we aimed to evaluate biochemical and physiological changes occurring within Hypnea musciformis after short-term exposure to gasoline. Hypnea musciformis was cultivated without gasoline and then exposed to various concentrations of it (0.001 % - 1.0 %, v/v) for periods of 30 min, 1 h, 12 h and 24 h. A Pricncipal Compound Analysis of UV-vis spectral window (200-700 nm) was able to discriminate gasoline-exposed samples according to both exposure time and gasoline concentration. Changes in carotenoid profile composition were observed. Decreased carotenoid content was associated to gasoline exposure time, being lutein and trans-β-carotene the major compounds found. Higher gasoline concentrations negatively interfered with phenolic compounds accumulation. In addition, increased gasoline concentrations corresponded to decreased intracellular starch grains content as well as increased its deposition on cell wall external surface. Data obtained allow us to conclude that gasoline can damage Hypnea musciformis physiology and cell morphology. This is important, considering Hypnea musciformis carotenoids and phenolics are potential biomarkers of environmental stress investigated, as well as its increased cell wall thickness to avoid gasoline diffusion.

Resumo O município de Caçapava do Sul é responsável por 80% da produção de pó de rocha do estado, e seu 1° distrito se localiza no entorno de quatro mineradoras de mármore. O aumento significativo da extração mineral no Brasil implica em sérios problemas ambientais. Um desses fatores é o desenvolvimento e a proliferação de patologias diretamente relacionadas aos recursos hídricos. A proposta desse estudo foi investigar a composição da água na área do 1º distrito. A investigação geoquímica das águas revelou águas classificadas como mole e duras, com pH neutro e alcalino. A condutividade elétrica varia de 95,7 a 548 μs cm-1, e a alcalinidade total varia de 57 a 241 mg L-1. Os teores de Ca e Mg variam entre 6,01 a 54,1 e 4,6 a 32,75, respectivamente. Todos os valores medidos atendem os padrões de potabilidade para consumo humano estabelecido pelas Portarias nº 2.914 de 2011 e nº 36/GM de 1990 e nº 1469 de 2000.

Abstract Caçapava do Sul, RS, Brazil produces 80% of the State’s rock-dust, and its 1st district is located near four marble quarries. A significant increase in Brazilian mineral extraction has caused serious environmental problems, such as the development and proliferation of diseases directly related to water resources. This study sought to investigate the water composition in the 1st district area. Geochemical investigation revealed waters classified as soft and hard, neutral and alkaline pH. Electric conductivity ranged from 95.7 to 548 μs cm-1, and total alkalinity ranged from 57 to 241 mg L-1. Ca and Mg ranged from 6.01 to 54.1 and from 4.6 to 32.75, respectively. All measured values met the potability standards for human consumption established by Ordinance Nos. 2914 (2011), 36-GM/1990, and1469/2000.

Abstract The objective of this research was to evaluate the ability and efficiency of different software tools for the deconvolution of DSC thermograms of protein denaturation in salted beef. The salted samples were obtained by immersing beef pieces in NaCl solutions with concentrations of 20, 50, 100 and 330 g NaCl L-1 of water for 48 hours at 10 °C. The raw beef were used as control samples. Three software tools were considered: (i) Pyris7, (ii) OriginPro v.8, and (iii) Solver tool from MS-Excel. These computer programs were used for estimating the thermal denaturation temperature of myosin, sarcoplasmic proteins, and actin, as well as the value of denaturation enthalpy of these proteins. Based on the results obtained, we concluded that the model developed and programmed in MS-Excel showed better agreement with the data found in literature than the results obtained with the Pyris and OriginPro tools.

The aim was to know the perception of crack/cocaine users about the use and treatment in a midsize general hospital, located in Rio Grande do Sul. It is a qualitative, descriptive and exploratory research that used semi-structured interviews with eight crack users, from September to October 2010. To analyze the data, we used content analysis from which two semantic categories emerged: drug use and seeking treatment. It was evidenced that drug use initiation in adolescence is related to social access or easy economic access, excessive load on studies and work, stress and not knowing about the possibility of chemical dependency, friends and family members influences, who also influence them on seeking treatment. We conclude that it is necessary to investigate the issue of crack users better and support actions on consume reduction, prevention and education to users.

El objetivo fue conocer la percepción de los consumidores de crack sobre el uso y tratamiento en un hospital general de tamaño mediano, que se encuentra en Río Grande do Sul. Se trata de una investigación cualitativa, descriptiva y exploratoria que utilizó la entrevista semiestructurada con ocho usuarios de crack, de septiembre a octubre de 2010. Para analizar los datos, se utilizó el análisis de contenido a partir de la cual emergieron dos temas: el uso de drogas y la búsqueda de tratamiento. Se evidenció que el inicio del consumo de drogas en la adolescencia se relaciona con acceso social o económico fácil, la carga excesiva de los estudios y trabajo, estrés y no saber acerca de la posibilidad de la dependencia química, amigos y miembros de la familia influye tanto que estos influyen también en la búsqueda de tratamiento. Llegamos a la conclusión de que es necesario conocer mejor el problema del crack y apoyar las acciones de reducción de consumo, prevención y educación a los usuarios.

O objetivo foi conhecer a percepção dos usuários de crack em relação ao uso e ao tratamento, em hospital geral, de médio porte, localizado no Rio Grande do Sul. Trata-se de uma pesquisa qualitativa, descritiva e exploratória, que utilizou a entrevista semiestruturada, com oito usuários de crack, de setembro a outubro de 2010. Para analisar os dados, utilizou-se a análise de conteúdo da qual emergiram duas categorias temáticas: uso de drogas e busca por tratamento. Evidenciou-se que o início do uso das drogas, na adolescência, relaciona-se ao acesso social ou econômico fácil, à carga excessiva no estudo e trabalho, ao estresse e ao desconhecimento da possibilidade de dependência química, influências de amigos e de familiares, sendo que estes também influenciam na busca pelo tratamento. Concluiu-se que é necessário conhecer melhor o problema do crack e apoiar as ações voltadas à redução do consumo, da prevenção e da educação aos usuários.

O objetivo foi conhecer a percepção dos usuários de crack em relação ao uso e ao tratamento, em hospital geral, de médio porte, localizado no Rio Grande do Sul. Trata-se de uma pesquisa qualitativa, descritiva e exploratória, que utilizou a entrevista semiestruturada, com oito usuários de crack, de setembro a outubro de 2010. Para analisar os dados, utilizou-se a análise de conteúdo da qual emergiram duas categorias temáticas: uso de drogas e busca por tratamento. Evidenciou-se que o início do uso das drogas, na adolescência, relaciona-se ao acesso social ou econômico fácil, à carga excessiva no estudo e trabalho, ao estresse e ao desconhecimento da possibilidade de dependência química, influências de amigos e de familiares, sendo que estes também influenciam na busca pelo tratamento. Concluiu-se que é necessário conhecer melhor o problema do crack e apoiar as ações voltadas à redução do consumo, da prevenção e da educação aos usuários.

The aim was to know the perception of crack/cocaine users about the use and treatment in a midsize general hospital, located in Rio Grande do Sul. It is a qualitative, descriptive and exploratory research that used semi-structured interviews with eight crack users, from September to October 2010. To analyze the data, we used content analysis from which two semantic categories emerged: drug use and seeking treatment. It was evidenced that drug use initiation in adolescence is related to social access or easy economic access, excessive load on studies and work, stress and not knowing about the possibility of chemical dependency, friends and family members influences, who also influence them on seeking treatment. We conclude that it is necessary to investigate the issue of crack users better and support actions on consume reduction, prevention and education to users.

El objetivo fue conocer la percepción de los consumidores de crack sobre el uso y tratamiento en un hospital general de tamaño mediano, que se encuentra en Río Grande do Sul. Se trata de una investigación cualitativa, descriptiva y exploratoria que utilizó la entrevista semiestructurada con ocho usuarios de crack, de septiembre a octubre de 2010. Para analizar los datos, se utilizó el análisis de contenido a partir de la cual emergieron dos temas: el uso de drogas y la búsqueda de tratamiento. Se evidenció que el inicio del consumo de drogas en la adolescencia se relaciona con acceso social o económico fácil, la carga excesiva de los estudios y trabajo, estrés y no saber acerca de la posibilidad de la dependencia química, amigos y miembros de la familia influye tanto que estos influyen también en la búsqueda de tratamiento. Llegamos a la conclusión de que es necesario conocer mejor el problema del crack y apoyar las acciones de reducción de consumo, prevención y educación a los usuarios.

Com o objetivo de determinar a exigência nutricional de treonina digestível para poedeiras comerciais leves de segundo ciclo de produção (79 a 95 semanas de idade), foi conduzido um experimento com 180 poedeiras Lohmann LSL, distribuídas em cinco dietas (0,380; 0,413; 0,446; 0,479; e 0,512% de treonina digestível), seis repetições e seis aves por unidade experimental. Os níveis de treonina na ração tiveram efeito quadrático sobre o consumo de ração, a conversão alimentar por massa e por dúzia de ovos, a taxa de postura, o peso e a massa de ovos. Não foi observado efeito significativo dos níveis de treonina na ração sobre o ganho de peso, a unidade Haugh, o índice de gema e de albúmen e a porcentagem de gema e de albúmem, com exceção da porcentagem de casca, que sofreu efeito quadrático. Mediante análise estatística e interpretação biológica e tomando-se a conversão alimentar por dúzia de ovos como parâmetro decisório, a exigência de treonina digestível no período de 79 a 95 semanas de idade é de 0,469%, que corresponde a um consumo de treonina de 459 mg/ave/dia.

In order to determine nutritional requirement of digestible threonine for white-egg laying hens in the second production cycle (from 79 to 95 weeks of age), it was carried out an experiment with 180 commercial Lohmann LSL laying hens, distributed in five diets (0.380; 0.413; 0.446; 0.479 and 0.512% digestible threonine), six replicates and six birds per experiment unit. Levels of threonine in the ration quadratically affected feed intake, feed conversion per mass and per dozen of eggs, laying rate, weight and mass of eggs. It was not observed significant effect of the levels of threonine in the ration on weight gain, Haugh unity, index of yolk and albumen and percentage of yolk and albumen, except for shell percentage, which was quadratically affected. Through statistic analyzes and biological interpretation and using feed conversion per dozen of eggs as a decision parameter, the requirement of digestible threonine in the period from 79 to 95 weeks of age is 0.469%, corresponding to a threonine consumption of 459 mg/bird/day.

Foi conduzido um experimento com o objetivo de estabelecer a exigência nutricional de metionina+cistina para poedeiras leves no segundo ciclo de produção. Foram utilizadas 180 poedeiras leves no período de 79 a 95 semanas de idade, submetidas a uma ração basal deficiente em metionina+cistina e suplementada com 0,00; 0,053; 0,108; 0,161; ou 0,214% de DL-metionina (98%), de forma a proporcionar 0,490; 0,542; 0,594; 0,648; e 0,698% de metionina+cistina digestíveis nas rações. Os níveis de suplementação obedeceram às relações de metionina+cistina:lisina de 75, 83, 91, 99 e 107 com a lisina fixada em 0,653%. O delineamento experimental foi inteiramente casualizado, com cinco níveis de metionina+cistina, seis repetições e seis aves por unidade experimental. Os níveis de metionina+cistina na ração tiveram efeito linear sobre a conversão alimentar por dúzia e por massa de ovos, a taxa de postura, a massa de ovos e o índice de albúmen e efeito quadrático sobre o peso dos ovos e a unidade Haugh. A porcentagem dos componentes dos ovos não foram influenciada pelos níveis de metionina+cistina na ração. A exigência de metionina+cistina para poedeiras leves é superior a 0,698%, valor que corresponde a consumo de pelo menos de 796 mg/ave/dia.

It was conducted an experiment with the objective of setting the nutritional requirement of methionine+cystine for white-egg laying hens in the second production cycle. It was used 180 white-egg laying hens from 79 to 95 weeks of age submitted to a basal diet deficient in methionine+cystine, supplemented with 0.00; 0.053; 0.108; 0.161 or 0.214% of DL-methionine (98%) to provide 0.490; 0.542; 0.594; 0.648 and 0.698% of digestible methionine+cystine in the rations. Levels of supplementation followed ratios of methionine+cystine:lysine of 75, 83, 91, 99 and 107 with lysine fixed at 0.653%. A complete randomized design with five levels of methionine + cystine was used, with six replicates and six birds per experimental unit. Levels of methionine+cystine in the ration linearly affected feed conversion per dozen of eggs and mass of eggs, laying rate, egg mass and albumen index and they quadratically affected weight of eggs and Haugh unity. Percentage of components of the eggs was not affected by levels of methionine+cystine in the ration. Requirement of methionine+cystine for white-egg laying hens is higher than 0.698%, which corresponds to a consumption of at least 796 mg/bird/day.

Um experimento foi conduzido com o objetivo de estimar o nível ótimo de treonina digestível para poedeiras leves e semipesadas no segundo ciclo de postura. Foram utilizadas 360 aves, sendo 180 poedeiras leves e 180 poedeiras semipesadas, distribuídas em delineamento inteiramente casualizado, num arranjo fatorial 5 x 2 (5 níveis de treonina x 2 linhagens de poedeiras). Os níveis de treonina digestível utilizados foram de 0,380; 0,413; 0,445; 0,478 e 0,511%. Foram avaliados os dados de desempenho (produção, peso e massa de ovo), componentes dos ovos (albúmen, gema e casca), a qualidade interna dos ovos (unidades Haugh, índice de albúmen e de gema), percentual de ovos não comerciais e parâmetros de peso corporal. Pelos resultados obtidos, estimou-se para poedeiras leves nível de 0,446% de treonina digestível, correspondendo a um consumo diário de 487 mg/ave e relação treonina/lisina igual a 68, enquanto que para poedeiras semipesadas o nível estimado foi de 0,465% de treonina digestível, com consumo diário de 505 mg/ave e relação treonina/lisina igual a 71. Comparando a relação mg de treonina digestível por grama de ovo produzido, foram estimados valores de 9,5 e 10,0 mg de treonina/grama de ovo produzida.

An experiment was carried out to estimate the optimum level of digestible threonine for white-egg and brown-egg laying hens in the second laying cycle. It was used 360 laying hens, 180 were white-egg and 180 were brown-egg laying hens which were distributed in a complete randomized design in 5 x 2 factorial arrangement (5 levels threonine x 2 lines of laying hens). The levels of digestible threonine used were the following: 0.380, 0.413, 0.445, 0.478 and 0.511%. It was evaluated performance data (production, egg weight and mass), egg components (albumen, yolk and shell), egg internal quality (Haugh units, albumen and yolk indexes) and percentage of non-commercial eggs and body weight parameters. Through the obtained results, it was estimated for white-egg laying hens, levels of digestible threonine of 0.446%, which matches a daily intake of 487 mg/hens and a lysine: threonine relationship equal to 68; for brown-egg laying hens, the estimate level of digestible threonine was 0.465% with a daily intake of 505 mg/hens and a lysine: threonine relationship of 71. By comparing the relationship mg digestible threonine per gram of produced eggs, values of 9.5 and 10.0 mg threonine/gram egg are estimate; gram of produced egg.

Com o objetivo de determinar a exigência nutricional de treonina digestível para poedeiras comerciais de segundo ciclo de produção, período de 79 a 95 semanas de idade, foi conduzido um experimento com 180 poedeiras semipesadas, distribuídas em cinco níveis de treonina digestível (0,380; 0,413; 0,446; 0,479; e 0,512%), cada um com seis repetições de seis aves. Os níveis de treonina na ração tiveram efeito quadrático sobre o consumo de ração, a conversão alimentar por massa e por dúzia de ovos, a taxa de postura, o peso e a massa de ovos. O consumo de treonina digestível aumentou linearmente de acordo com os níveis de treonina na ração. Não foi observado efeito dos níveis de treonina digestível na ração sobre o ganho de peso, os índices de gema e de albúmen e as porcentagens de casca, gema e albúmen do ovo, com exceção da unidade Haugh, que aumentou de forma quadrática conforme os níveis de treonina digestível da ração. Considerando a conversão alimentar por dúzia de ovos, a exigência de treonina digestível para poedeiras comerciais no período de 79 a 95 semanas de idade é de 0,467%, que corresponde a um consumo de 462 mg de treonina/ave/dia.

The objective of this work is to determine the nutritional requirement of digestible threonine for brown-egg laying hens between 79 to 95 weeks of age. For this experiment, 180 commercial Lohmann Brown laying hens were used, distributed in five digestible threonine levels (0.380; 0.413; 0.446; 0.479 and 0.512%), each one with six replicates and six hens/replicate. It was observed a quadratic effect of threonine levels on the feed intake, egg mass conversions, egg dozen conversions, egg production, egg weight, and egg mass. The digestible threonine intake increased linearly in function of diet threonine levels. It was not observed effect of diet threonine levels for weight gain, yolk index, albumen index, shell percentage, yolk percentage and albumen percentage, except for the Haugh units, which increased in a quadratic way according to digestible threonine levels in the feed. Regarded to the food conversion per egg dozen, the requirement of digestible threonine for commercial hens in the period between 79 to 95 weeks of age is 0.467%, which corresponds to an intake of 462 mg threonine/hen/day.

The effect of fluoride ions concentration on the electrochemical behavior of Ti grade 2 and Ti6Al4V in citrate buffers was studied. Open circuit potential (OCP) measurements and voltammetric studies of the samples in the fluoride containing citrate buffers revealed a dissolution process when the pH falls below 5.0 and the NaF content is higher than 0.01 M. However, in citrate pH 7.6 the materials showed a passive behavior even in 0.1 M NaF. Some micrographs of Ti grade 2 obtained after longer immersion times in citrate pH 5.0 with 0.01 M NaF showed a surface attack. EIS (Electrochemical Impedance Sprectroscopy) data obtained at the OCP revealed that the film resistance decreases when the immersion time is increased in pH 5.0 containing 0.1 M NaF. In the citrate pH 7.6 the EIS data indicated a two-layer model of an oxide film consisting of a more compact inner layer and a porous outer layer. On the other hand, the EIS results in citrate pH 4.0 change significantly when the fluoride ions concentration increases from 0.01 to 0.05 M. The electrochemical data revealed that the corrosion behavior of Ti grade 2 and Ti6Al4V in the citrate buffers depends on the pH, the fluoride content and the exposure time.

Um experimento foi conduzido com o objetivo de estabelecer a exigência nutricional de metionina + cistina (met + cist) para poedeiras semipesadas no segundo ciclo de produção. Utilizaram-se 180 poedeiras semipesadas no período de 79 a 95 semanas de idade alimentadas com uma ração basal deficiente em met + cist (0,490%) suplementada com 0,00; 0,053; 0,108; 0,161; e 0,214% de DL-metionina (98%), de forma a proporcionar 0,490; 0,542; 0,594; 0,648; e 0,698% de met + cist digestível. Os níveis de suplementação de met + cist obedeceram, respectivamente, às relações de 75, 83, 91, 99 e 107 com lisina. O delineamento experimental foi o inteiramente casualizado com cinco níveis de met + cist, seis repetições e seis aves por unidade experimental. Avaliaram-se os consumos de ração e de met + cist, a conversão alimentar por dúzia e por massa de ovos, o ganho de peso, a taxa de postura, o peso e a massa de ovos, a porcentagem dos componentes dos ovos e a qualidade interna dos ovos. Os níveis de met + cist tiveram efeito linear positivo sobre a conversão alimentar por dúzia de ovos, efeito quadrático sobre o consumo de ração, o ganho de peso e a conversão alimentar. Os níveis de met + cist tiveram efeito linear positivo sobre a taxa de postura e efeito quadrático sobre o peso e a massa de ovos. Observaram-se ainda efeito quadrático sobre a unidade Haugh e efeito linear sobre o índice de gema. A exigência de met + cist é igual ou superior a 0,698%, que corresponde a consumo mínimo de 786 mg de met + cist digestível/ave.dia.

An experiment study was carried out to establish the nutritional requirement of methionine + cystine (met + cyst) for brown-egg laying hens, in the second production cycle. One hundred and eighty Lohmann Brown birds from 79 and 95 weeks of age were used fed a base diet deficient in met + cyst, supplemented with 0.00; 0.053; 0.108; 0.161 and 0.214% DL-Methionine (98%), providing 0.490; 0.542; 0.594; 0.648 and 0.698% digestible met + cyst. The levels supplementation of met + cyst followed the lysine relations (0.653%) of 75, 83, 91, 99 and 107. A complete randomized design with five levels of met + cyst, six replications/treatment and six birds per experimental unit was used. The feed intake, met + cyst intake, feed conversion per dozen eggs and egg mass, weight gain, egg production, egg weight, egg mass, percentage of the egg components and the internal quality of the eggs were evaluated. A positive linear effect was obtained for food conversion per dozen eggs. A quadratic effect was observed of the met + cyst levels on diet intake, weight gain and food conversion. The met + cyst levels had a positive linear effect on the laying rate and quadratic effect on egg weight and mass. A quadratic effect was also observed of the on the Haugh unit and linear effect on yolk index. The requirement of met + cyst is higher or equal to 0.698%, that corresponds to a minimum intake of at least 786 mg digestible met + cyst/bird/day.

Com o objetivo de determinar a exigência nutricional de lisina digestível para poedeiras de segundo ciclo de produção no período de 79 a 95 semanas de idade, conduziu-se um experimento utilizando 180 poedeiras Lohmann Brown, distribuídas em cinco níveis de lisina digestível (0,555; 0,605; 0,655; 0,705; e 0,755%), seis repetições e seis aves por unidade experimental. O consumo de ração e a conversão alimentar por dúzia de ovos não foram influenciados pelos níveis de lisina. O efeito foi linear positivo sobre o consumo de lisina e quadrático sobre a conversão alimentar por massa de ovos. O peso e a massa de ovos apresentaram resposta quadrática aos níveis de lisina. A porcentagem dos componentes dos ovos e a qualidade interna não foram influenciadas pelos níveis de lisina, com exceção do índice de gema, que sofreu efeito quadrático. A exigência de lisina digestível para poedeiras semipesadas no segundo ciclo de postura foi estimada em 0,681%, o que equivale a consumo diário de 783 mg de lisina digestível.

With the objective of determining the nutritional requirement of digestible lysine for brown-egg laying hens from 79 to 95 weeks of age, an experiment was carried out using 180 commercial Lohmann Brown laying hens, distribuited in five treatments (0.555; 0.605; 0.655; 0.705 and 0.755%), six replications and six birds birds/replication. The feed intake and the food conversion per dozen of eggs were not influenced by the lysine levels. There was a positive linear effect on lysine intake and quadratic on feed conversion for egg mass. Egg mass and weight presented a quadratic response to the lysine levels. The egg component percentage and the internal quality were not influenced by the levels of lysine, except for the yolk index, which showed quadratic effect. The digestible lysine requirement for brown-egg laying hens on the 2nd production cycle of production was 0.681% lysine, that corresponds to a daily intake of 783 mg digestible lysine.