This study was designed to determine the impact of glycerol hyperhydration, compared with a placebo hyperhydration, on the run performance during an Olympic distance triathlon. Ten competitive triathletes (mean peak oxygen consumption, VO2 peak = 65.5 ± 5.5 ml.kg.-1min-1) undertook two simulated Olympic Distance Triathlons in 31° C and 61% relative humidity. The trials were split into two work phases: a fixed workload phase comprising a 18-20 min swim and a 60 min cycle and, a self regulated time trial run over 10 kilometres conducted on a treadmill. One hundred and fifty min prior each trial, either a glycerol solution (1 g.kg.-1 body mass (BM) in a 4% carbohydrate – electrolyte drink) or a placebo of equal volume of the 4% carbohydrate-electrolyte solution was ingested over one hour. The total fluid intake in each trial was 23 ml.kg.-1 BM. A randomised, double blind, cross over design was used. Due to either 1) the arduous nature of the trials 2) the side effects associated with the ingestion of glycerol 3) or the combination of the two aforementioned reasons, only five of the 10 subjects completed the final 10 km self regulated time trial for both treatments. Only the data obtained from these five subjects were reported in this study. Glycerol ingestion expanded body water over the placebo by 154 ml (26%). At 60 and 90 min after the start of drinking, urine output was significantly higher with glycerol than placebo treatment (216.4, 366.4 ml vs 81.0, 242.0 ml, respectively) but significantly higher at 120 min in the placebo (421.6 ml vs 131.2 ml). There were no significant differences in heart rate and rectal temperature during the swim and cycle phases. However, there were significant increases in heart rate (at 5, 10, 15, 25 and 30 min) and rectal temperature (at 5, 20 and 30 min) during the 10 km run in the glycerol trial. The mean 10 km run time for the placebo trial was 40 min 21 sec (± 2.9 min) while the glycerol trial was 39 min 22 sec (± 2.0 min). The mean difference of 2.1% in finishing time between trials was not significant. Three of the five subjects in the glycerol trial improved their 10 km time by 7.0, 2.4 and 2.7%, respectively. The finishing time for one subject did not change for both trials while another subject had deteriorated by 2.3% in the glycerol trial. In the glycerol treatment, five subjects complained of bloating and nausea while only one subject complained of feeling unwell in the placebo treatment. Data from this study have shown that glycerol hyperhydration did not significantly improve performance while plasma volume expansion and subsequent lower rectal temperature and lower heart rates were not evident. The exact mechanisms of how glycerol hyperhydration can improve performance warrant further investigation. / Masters in Applied Science

This study was designed to determine the impact of glycerol hyperhydration, compared with a placebo hyperhydration, on the run performance during an Olympic distance triathlon. Ten competitive triathletes (mean peak oxygen consumption, VO2 peak = 65.5 ± 5.5 ml.kg.-1min-1) undertook two simulated Olympic Distance Triathlons in 31° C and 61% relative humidity. The trials were split into two work phases: a fixed workload phase comprising a 18-20 min swim and a 60 min cycle and, a self regulated time trial run over 10 kilometres conducted on a treadmill. One hundred and fifty min prior each trial, either a glycerol solution (1 g.kg.-1 body mass (BM) in a 4% carbohydrate – electrolyte drink) or a placebo of equal volume of the 4% carbohydrate-electrolyte solution was ingested over one hour. The total fluid intake in each trial was 23 ml.kg.-1 BM. A randomised, double blind, cross over design was used. Due to either 1) the arduous nature of the trials 2) the side effects associated with the ingestion of glycerol 3) or the combination of the two aforementioned reasons, only five of the 10 subjects completed the final 10 km self regulated time trial for both treatments. Only the data obtained from these five subjects were reported in this study. Glycerol ingestion expanded body water over the placebo by 154 ml (26%). At 60 and 90 min after the start of drinking, urine output was significantly higher with glycerol than placebo treatment (216.4, 366.4 ml vs 81.0, 242.0 ml, respectively) but significantly higher at 120 min in the placebo (421.6 ml vs 131.2 ml). There were no significant differences in heart rate and rectal temperature during the swim and cycle phases. However, there were significant increases in heart rate (at 5, 10, 15, 25 and 30 min) and rectal temperature (at 5, 20 and 30 min) during the 10 km run in the glycerol trial. The mean 10 km run time for the placebo trial was 40 min 21 sec (± 2.9 min) while the glycerol trial was 39 min 22 sec (± 2.0 min). The mean difference of 2.1% in finishing time between trials was not significant. Three of the five subjects in the glycerol trial improved their 10 km time by 7.0, 2.4 and 2.7%, respectively. The finishing time for one subject did not change for both trials while another subject had deteriorated by 2.3% in the glycerol trial. In the glycerol treatment, five subjects complained of bloating and nausea while only one subject complained of feeling unwell in the placebo treatment. Data from this study have shown that glycerol hyperhydration did not significantly improve performance while plasma volume expansion and subsequent lower rectal temperature and lower heart rates were not evident. The exact mechanisms of how glycerol hyperhydration can improve performance warrant further investigation. / Masters in Applied Science

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Thesis (Ph.D.)--University of Wyoming, 2008. / Title from PDF title page (viewed on August 9, 2009). Includes bibliographical references (p. 160-199).

Thesis (Ph. D.) -- University of Texas Southwestern Medical Center at Dallas, 2006. / Embargoed. Vita. Bibliography: 134-139.

Orientador: Rosemeire da Silva Filardi / Resumo: Em diversas regiões do Brasil, o desempenho das aves é afetado negativamente pelas variações climáticas. Altas temperaturas associadas a alta umidade relativa do ar determinam muitas alterações fisiológicas, dentre elas os distúrbios acidobásicos, diminuição no desempenho produtivo das aves e na qualidade externa dos ovos. Dentro desta problemática, o estudo avaliou os efeitos de níveis do balanço parcial de cátions-ânions na dieta (Na+ + K+ - Cl-), balanço eletrolítico (BE), sobre as respostas produtivas, qualidade dos ovos, hemograma e parâmetros bioquímicos de poedeiras comerciais em segundo ciclo de produção, mantidas em condições de altas temperaturas e umidade. Cento e vinte e oito poedeiras comerciais em segundo ciclo produtivo, com 122 semanas de idade, foram distribuídas em um delineamento inteiramente casualizado em esquema de parcelas subdivididas, onde ciclo foi considerado como apenas uma medida repetida no tempo, composto por quatro balanços eletrolíticos (170, 220, 270, 320 mEq.kg-1), quatro repetições de oito aves cada em quatro ciclos de 14 dias, perfazendo um total de 56 dias de experimento. Ao final do experimento foram obtidas amostras sanguíneas de duas aves por parcela para determinar o hemograma e parâmetros bioquímicos sanguíneos. Os BE influenciaram o consumo de ração (P<0,01), a produção (P<0,05) e massa de ovos (P<0,01), tendo comportamento quadrático para essas variáveis. Considerando-se o comportamento da produção e da massa de ovos o valor médio ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In several regions of Brazil, the performance of laying hens is affecting negatively by climatic variations. High temperatures and relative humidity determine many physiological changes, among them the acid-base disturbances, decrease in the productive performance of the laying hens and the external quality of the eggs. In this problem, the study evaluated the effects of partial levels of cation-anions in the diet (Na+ + K+ - Cl-), electrolytic balance (BE), on productive responses, egg quality, hemogram and biochemical parameters of laying hens in the second production cycle maintained under high temperature and humidity conditions. One hundred and twenty-eight commercial laying hens in the second productive cycle, at 122 weeks of age, were distributed in a completely randomized design in subdivided plots scheme, where cycle was considered as only one measure repeated in time, composed of four electrolytic balances (170 , 220, 270, 320 mEq.kg-1), four replicates of eight laying hens each in four cycles of 14 days, making a total of 56 days of experiment. At the end of the experiment blood samples of two laying hens were obtained per plot to determine the hemogram and blood biochemical parameters. The BE influenced feed intake (P <0.01), production (P <0.05) and egg mass (P <0.01), with quadratic behavior for these variables. Considering the production behavior and egg mass, the mean electrolytic balance value 265.24 mEq.kg-1 provided the best result. Within the ranges of the... (Complete abstract click electronic access below) / Mestre

LIMA, Raffaella Castro. Níveis de sódio para codornas japonesas (Coturnix xotunix japonica) nas fases de crecimento e postura. 2009. 92 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Zootecnia, Programa de Pós-Graduação em Zootecnia, Fortaleza-CE, 2009. / Submitted by guaracy araujo (guaraa3355@gmail.com) on 2016-08-09T18:38:29Z No. of bitstreams: 1 2009_dis_rclima.pdf: 280140 bytes, checksum: ec9fb17c2197428e5f5b407d68b654a2 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-10T15:19:18Z (GMT) No. of bitstreams: 1 2009_dis_rclima.pdf: 280140 bytes, checksum: ec9fb17c2197428e5f5b407d68b654a2 (MD5) / Made available in DSpace on 2016-08-10T15:19:18Z (GMT). No. of bitstreams: 1 2009_dis_rclima.pdf: 280140 bytes, checksum: ec9fb17c2197428e5f5b407d68b654a2 (MD5) Previous issue date: 2009 / With the aim to evaluate the effects of the sodium levels in the growth and laying phases of Japanese quails, we conducted two experiments in which we evaluated the sodium levels of de 0,07%; 0,12%; 0,17%; 0,22%; 0,27% and 0,32%. In the first experiment (growth phase), 480 quails with one day were distributed in a completely randomized design with six treatments of eight replications of ten birds each. According to the results, in the period from 1 to 21 days, there was a linear increase in feed and water intake with the increase in sodium levels and a quadratic effect in the weight gain and feed conversion with optimum sodium levels of 0,23% and 0,21%, respectively. In the period from 21 to 42 days, there was a linear reduction in the weight gain, linear increase in water intake and worse in feed conversion with the increase in sodium in the ration, while feed intake was not affected. In the total period (1 to 42 days of age) with the increase in sodium in the ration, we observed a linear increase in the water intake and in the excreta moisture and a quadratic effect on the digestibility of the dry matter (DCMS), nitrogen (CDN), gross energy (DCEB) and values of apparent metabolizable energy (AME) and apparent corrected (AMEn) with estimated optimum levels of 0,20% for DCMS, 0,27% for CDN and 0,19% for DCEB, AME and AMEn. Moreover, in this experiment we observed that the performance of the laying phase was not influenced significantly by the sodium level supplied to quails in the growth phase. In the second experiment, 288 quails with 16 weeks of age were distributed at random in six treatments with eight replications of six birds each. There was a linear increase in feed intake, in water intake, and in egg weight with the increase in sodium levels and a quadratic effect for egg production, egg mass and feed conversion with optimum sodium levels of 0,23%, 0,24% and 0,23%, respectively. Also, there was a quadratic effect of the sodium levels for percentages the yolk, shell and albumen, obtaining a maximum proportion of albumen and shell and a minimum proportion of yolk with a 0,21% sodium level. There was no significant effect of the sodium levels for the Haugh Units. However, there was a quadratic for specific gravity, with an optimum sodium level of 0.22%. The increase in sodium content did not affect the excreta moisture, but there was a quadratic effect on the digestibility of dry matter (DCMS), nitrogen (CDN), gross energy (DCEB) and values of apparent metabolizable energy (AME) and apparent corrected (AMEn) with estimated optimum levels of 0,24% for CDMS, 0,22% for CDN, 0,21% for CDEB and 0,18% for AME and AMEn. Considering the results, we can recommend that the diets for Japanese quails in the growth phase (1 to 42 days) are formulated with sodium levels between 0,12% and 0,23% and in the production phase with sodium levels between 0,18% and 0,23% / Com o objetivo de avaliar os efeitos dos níveis de sódio da ração nas fases de crescimento e de postura de codornas japonesas foram realizados dois experimentos, nos quais, foram avaliados os níveis de 0,07; 0,12; 0,17; 0,22; 0,27 e 0,32% de sódio. No primeiro experimento (fase de crescimento), 480 codornas com um dia de idade, foram distribuídas em um delineamento inteiramente casualizado, com seis tratamentos de oito repetições de dez aves cada. Conforme os resultados, no período de 1 a 21 dias, houve aumento linear do consumo de ração e água com aumento dos níveis de sódio e efeito quadrático no ganho de peso e conversão alimentar com níveis ótimos de 0,23% e 0,21% de sódio, respectivamente. De 21 a 42 dias, houve redução linear no ganho de peso, aumento linear no consumo de água e prejuízo na conversão alimentar com o acréscimo de sódio na ração, enquanto, o consumo de ração não foi influenciado. No período total (1 a 42 dias de idade) com o aumento de sódio na ração, observou-se aumento linear no consumo de água e na umidade das excretas e efeito quadrático sobre a digestibilidade da matéria seca (CDMS), nitrogênio (CDN), energia bruta (CDEB) e valores energia metabolizável aparente (EMA) e aparente corrigida (EMAn) com níveis ótimos estimados de 0,20% para CDMS, 0,27% para o CDN e 0,19% para CDEB, EMA e EMAn. Ainda, nesse ensaio, observou-se que o desempenho da fase de postura não foi influenciado significativamente pelo nível de sódio recebido pelas codornas na fase de crescimento. No segundo experimento, 288 codornas com 16 semanas de idade foram distribuídas ao acaso em seis tratamentos com oito repetições de seis aves por unidade experimental. Houve aumento linear do consumo de ração, consumo de água e peso do ovo com o acréscimo de sódio e efeito quadrático para produção de ovos, massa de ovo e conversão alimentar com níveis ótimos de 0,23%, 0,24% e 0,23% de sódio, respectivamente. Também, houve efeito quadrático dos níveis de sódio para as percentagens de gema, casca e albúmen, obtendo-se máxima proporção de albúmen e casca e mínima de gema com 0,21% de sódio. Não houve efeito significativo dos níveis de sódio para Unidades Haugh, entretanto houve feito quadrático para gravidade específica, com nível ótimo de 0,22% de sódio. O acréscimo de sódio não afetou a umidade das excretas, mas houve efeito quadrático sobre a digestibilidade da matéria seca (CDMS), nitrogênio (CDN), energia bruta (CDEB) e valores energia metabolizável aparente (EMA) e aparente corrigida (EMAn) com níveis ótimos estimados de 0,24% para CDMS, 0,22% para CDN, 0,21% para CDEB e 0,18% para EMA e EMAn. Considerando os resultados, pode-se recomendar que as rações para codornas japonesas na fase de crescimento (1 a 42 dias) sejam formuladas com níveis de sódio entre 0,12% e 0,23% e na fase de produção, com níveis entre 0,18% e 0,23% de sódio

Submitted by Leonardo Tedeschi null (leonardotedeschi@uol.com.br) on 2016-04-30T14:07:00Z No. of bitstreams: 1 Dissertacao-LeonardoTedeschi.pdf: 1623389 bytes, checksum: 41374a3d719687f19252e03b62fc4848 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-03T16:25:14Z (GMT) No. of bitstreams: 1 tedeschi_l_me_ilha.pdf: 1623389 bytes, checksum: 41374a3d719687f19252e03b62fc4848 (MD5) / Made available in DSpace on 2016-05-03T16:25:14Z (GMT). No. of bitstreams: 1 tedeschi_l_me_ilha.pdf: 1623389 bytes, checksum: 41374a3d719687f19252e03b62fc4848 (MD5) Previous issue date: 2016-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste trabalho foi avaliar a viabilidade técnica e econômica da utilização de diferentes formas de cálculo e valores de balanço eletrolítico na formulação de rações para poedeiras comerciais no segundo ciclo de produção. Foram utilizadas 216 poedeiras comerciais leves, da linhagem Lohmann, em segundo ciclo de produção, distribuídas em um delineamento inteiramente casualizado em esquema fatorial (2 x 4 + 1) com parcela subdividida no tempo. Duas fórmulas de cálculo do Balanço Eletrolítico (Mongin = [Na+ + K+] – [Cl-] e Ender = [Na+ + K+] - [Cl- + S2-]) e quatro valores de Balanço Eletrolítico (170, 220, 270 e 320 mEq.kg-1) e uma dieta testemunha (sem fórmula ou valor para balanço eletrolítico) perfazendo um total de nove tratamentos com quatro repetições de seis aves cada, dividido em quatro ciclos, sendo que cada ciclo foi composto por 28 dias. Foram analisados parâmetros de desempenho das aves, qualidade dos ovos e qualidade dos ovos na vida de prateleira. As diferenças entre os tratamentos compostos pelas formulas e balanços eletrolíticos e o testemunha foram pouco consistentes sobre o desempenho ou qualidade dos ovo quando comparada a uma ração formulada sem esse conceito, porém a combinação da fórmula de Ender e do balanço eletrolítico de 270 mEq.kg-1 determinou maior retorno econômico. Na fórmula de Mongin o balanço eletrolítico determinou um comportamento quadrático para consumo de ração, massa de ovos, unidade Haugh de ovos frescos e estocados, indicando melhores resultados na faixa de 241,84 mEq.kg-1, porém o BE 170 mEq.kg-1 favoreceu a qualidade de ovos frescos ou armazenados. Para fórmula de Ender, o aumento no balanço eletrolítico determinou diminuição linear no consumo de ração, produção e massa do ovo e aumento linear na unidade Haugh de ovos frescos e armazenados. No balanço eletrolítico de 270 mEq.kg-1 o uso da fórmula de Ender se mostrou eficiente, conferindo melhor conversão alimentar e maior gravidade específica, além de proporcionar um maior retorno econômico. O aumento nos níveis de balanço eletrolítico promoveu maior excreção de água e potássio. / The objective of this study was to evaluate the technical and economic viability of using different forms of calculation and electrolyte balance in feed formulation for laying hens in the second production cycle. They were used 216 light commercial layers, Lohmann, second production cycle, distributed in a completely randomized design in a factorial scheme (2 x 4 + 1) with split-plot in time. Two calculation formulas of Electrolyte Balance (Mongin = [Na+ + K +] - [Cl] and Ender = [Na+ + K+] - [Cl- + S2-]) and four Electrolyte balance values (170, 220, 270 and 320 mEq.kg-1) and a control diet (no formula or value for electrolyte balance) for a total of nine treatments with four replicates of six birds each, divided into four cycles, each cycle consisted of 28 days. Performance parameters were analyzed for hens, egg quality and egg quality in shelf life. The differences between the treatments comprise the formulas and electrolyte balance and the witness were inconsistent about the performance or quality of the egg compared to a formulated diet without this concept, but the combination of Ender's formula and electrolyte balance 270 mEq.kg-1 determined a higher economic return. In Mongin’s formula the electrolyte balance determined a quadratic behavior for feed intake, egg mass, Haugh unit of fresh and stored eggs, indicating better results in the range of 241.84 mEq.kg-1, but electrolyte balance 170 mEq.kg-1 promoteted the quality of fresh or stored eggs. To Ender's formula, the increase in electrolyte balance determined linear decrease in feed intake, production and mass of the egg and linear increase in the Haugh unit of fresh and stored eggs. In the electrolyte balance of 270 mEq.kg-1 the use of Ender's formula proved to be efficient, providing better feed conversion ratio and higher specific gravity, in addition to providing greater economic return. The increase in electrolyte balance levels promoted increased excretion of water and potassium. / FAPESP: 2014/12820-5

Submitted by JESSICA PINOTI CAVALHIERI (j.cavalhieri@gmail.com) on 2018-05-09T16:12:04Z No. of bitstreams: 1 Jéssica Pinoti Cavalhieri-Dissertação.pdf: 1197873 bytes, checksum: cf0a8f252ebc6e8ade82bb4e367d0ee3 (MD5) / Approved for entry into archive by Cristina Alexandra de Godoy null (cristina@adm.feis.unesp.br) on 2018-05-09T17:41:06Z (GMT) No. of bitstreams: 1 cavalhieri_jp_me_ilha.pdf: 1197873 bytes, checksum: cf0a8f252ebc6e8ade82bb4e367d0ee3 (MD5) / Made available in DSpace on 2018-05-09T17:41:06Z (GMT). No. of bitstreams: 1 cavalhieri_jp_me_ilha.pdf: 1197873 bytes, checksum: cf0a8f252ebc6e8ade82bb4e367d0ee3 (MD5) Previous issue date: 2018-03-02 / Em diversas regiões do Brasil, o desempenho das aves é afetado negativamente pelas variações climáticas. Altas temperaturas associadas a alta umidade relativa do ar determinam muitas alterações fisiológicas, dentre elas os distúrbios acidobásicos, diminuição no desempenho produtivo das aves e na qualidade externa dos ovos. Dentro desta problemática, o estudo avaliou os efeitos de níveis do balanço parcial de cátions-ânions na dieta (Na+ + K+ - Cl-), balanço eletrolítico (BE), sobre as respostas produtivas, qualidade dos ovos, hemograma e parâmetros bioquímicos de poedeiras comerciais em segundo ciclo de produção, mantidas em condições de altas temperaturas e umidade. Cento e vinte e oito poedeiras comerciais em segundo ciclo produtivo, com 122 semanas de idade, foram distribuídas em um delineamento inteiramente casualizado em esquema de parcelas subdivididas, onde ciclo foi considerado como apenas uma medida repetida no tempo, composto por quatro balanços eletrolíticos (170, 220, 270, 320 mEq.kg-1), quatro repetições de oito aves cada em quatro ciclos de 14 dias, perfazendo um total de 56 dias de experimento. Ao final do experimento foram obtidas amostras sanguíneas de duas aves por parcela para determinar o hemograma e parâmetros bioquímicos sanguíneos. Os BE influenciaram o consumo de ração (P<0,01), a produção (P<0,05) e massa de ovos (P<0,01), tendo comportamento quadrático para essas variáveis. Considerando-se o comportamento da produção e da massa de ovos o valor médio de balanço eletrolítico 265,24 mEq.kg-1 proporcionou melhor resultado. Dentro dos intervalos dos balanços eletrolíticos avaliados não foram detectadas diferenças na qualidade externa dos ovos. Os resultados sanguíneos e bioquímicos não permitiram a indicação de balanço eletrolítico que possa favorecer uma melhor resposta das aves às condições de altas temperaturas e umidade. / In several regions of Brazil, the performance of laying hens is affecting negatively by climatic variations. High temperatures and relative humidity determine many physiological changes, among them the acid-base disturbances, decrease in the productive performance of the laying hens and the external quality of the eggs. In this problem, the study evaluated the effects of partial levels of cation-anions in the diet (Na+ + K+ - Cl-), electrolytic balance (BE), on productive responses, egg quality, hemogram and biochemical parameters of laying hens in the second production cycle maintained under high temperature and humidity conditions. One hundred and twenty-eight commercial laying hens in the second productive cycle, at 122 weeks of age, were distributed in a completely randomized design in subdivided plots scheme, where cycle was considered as only one measure repeated in time, composed of four electrolytic balances (170 , 220, 270, 320 mEq.kg-1), four replicates of eight laying hens each in four cycles of 14 days, making a total of 56 days of experiment. At the end of the experiment blood samples of two laying hens were obtained per plot to determine the hemogram and blood biochemical parameters. The BE influenced feed intake (P <0.01), production (P <0.05) and egg mass (P <0.01), with quadratic behavior for these variables. Considering the production behavior and egg mass, the mean electrolytic balance value 265.24 mEq.kg-1 provided the best result. Within the ranges of the electrolytic balance, no differences were detected in the external quality of the eggs. The blood and biochemical results did not allow the indication of electrolyte balance that could favor a better response of the laying hens to the conditions of high temperatures and relative humidity.

Orientador: Rosemeire da Silva Filardi / Resumo: O objetivo deste trabalho foi avaliar a viabilidade técnica e econômica da utilização de diferentes formas de cálculo e valores de balanço eletrolítico na formulação de rações para poedeiras comerciais no segundo ciclo de produção. Foram utilizadas 216 poedeiras comerciais leves, da linhagem Lohmann, em segundo ciclo de produção, distribuídas em um delineamento inteiramente casualizado em esquema fatorial (2 x 4 + 1) com parcela subdividida no tempo. Duas fórmulas de cálculo do Balanço Eletrolítico (Mongin = [Na+ + K+] – [Cl-] e Ender = [Na+ + K+] - [Cl- + S2-]) e quatro valores de Balanço Eletrolítico (170, 220, 270 e 320 mEq.kg-1) e uma dieta testemunha (sem fórmula ou valor para balanço eletrolítico) perfazendo um total de nove tratamentos com quatro repetições de seis aves cada, dividido em quatro ciclos, sendo que cada ciclo foi composto por 28 dias. Foram analisados parâmetros de desempenho das aves, qualidade dos ovos e qualidade dos ovos na vida de prateleira. As diferenças entre os tratamentos compostos pelas formulas e balanços eletrolíticos e o testemunha foram pouco consistentes sobre o desempenho ou qualidade dos ovo quando comparada a uma ração formulada sem esse conceito, porém a combinação da fórmula de Ender e do balanço eletrolítico de 270 mEq.kg-1 determinou maior retorno econômico. Na fórmula de Mongin o balanço eletrolítico determinou um comportamento quadrático para consumo de ração, massa de ovos, unidade Haugh de ovos frescos e estocados, indicando mel... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to evaluate the technical and economic viability of using different forms of calculation and electrolyte balance in feed formulation for laying hens in the second production cycle. They were used 216 light commercial layers, Lohmann, second production cycle, distributed in a completely randomized design in a factorial scheme (2 x 4 + 1) with split-plot in time. Two calculation formulas of Electrolyte Balance (Mongin = [Na+ + K +] - [Cl] and Ender = [Na+ + K+] - [Cl- + S2-]) and four Electrolyte balance values (170, 220, 270 and 320 mEq.kg-1) and a control diet (no formula or value for electrolyte balance) for a total of nine treatments with four replicates of six birds each, divided into four cycles, each cycle consisted of 28 days. Performance parameters were analyzed for hens, egg quality and egg quality in shelf life. The differences between the treatments comprise the formulas and electrolyte balance and the witness were inconsistent about the performance or quality of the egg compared to a formulated diet without this concept, but the combination of Ender's formula and electrolyte balance 270 mEq.kg-1 determined a higher economic return. In Mongin’s formula the electrolyte balance determined a quadratic behavior for feed intake, egg mass, Haugh unit of fresh and stored eggs, indicating better results in the range of 241.84 mEq.kg-1, but electrolyte balance 170 mEq.kg-1 promoteted the quality of fresh or stored eggs. To Ender's formula, the... (Complete abstract click electronic access below) / Mestre