Dietary fiber and zinc additives on performance and intestinal health of Escherichia coli challenged piglets

This study aimed to evaluate the effects of zinc oxide and a low level of encapsulated zinc oxide, with or without dietary fiber, on the performance and intestinal health of weaned piglets. A total of 112 piglets were used, divided into four treatment groups: basal diet with zinc oxide (ZnO); basal diet with zinc oxide and dietary fiber (ZnO+DF); basal diet with encapsulated low zinc oxide (LZnOE); and basal diet with LZnOE and DF (LZnOE+DF). Piglets were challenged with E . coli K88 + , weighed weekly and the fecal score was evaluated daily. One pig per pen was slaughtered to evaluate the production of volatile fatty acids, intestinal microbial populations, intestinal morphology, and digestibility. The encapsulated zinc resulted in lower body weight and average daily gain, but, when associated with dietary fiber, had similar results to zinc oxide. Until 49 days of age, zinc oxide reduced diarrhoea ( p 0.05). At 63 days of age the piglets subjected to LZnOE+DF treatment had lower diarrhoea than the pigs subjected to LZnOE treatment but higher than the ZnO and the ZnO+DF groups. Final weight and incidence of diarrhoea of pigs receiving LZnOE was worse than ZnO. LZnOE associated with DF provided the same final weight of piglets from the ZnO group.

Dietary fiber and zinc additives on performance and intestinal health of Escherichia coli challenged piglets

This study aimed to evaluate the effects of zinc oxide and a low level of encapsulated zinc oxide, with or without dietary fiber, on the performance and intestinal health of weaned piglets. A total of 112 piglets were used, divided into four treatment groups: basal diet with zinc oxide (ZnO); basal diet with zinc oxide and dietary fiber (ZnO+DF); basal diet with encapsulated low zinc oxide (LZnOE); and basal diet with LZnOE and DF (LZnOE+DF). Piglets were challenged with E . coli K88 + , weighed weekly and the fecal score was evaluated daily. One pig per pen was slaughtered to evaluate the production of volatile fatty acids, intestinal microbial populations, intestinal morphology, and digestibility. The encapsulated zinc resulted in lower body weight and average daily gain, but, when associated with dietary fiber, had similar results to zinc oxide. Until 49 days of age, zinc oxide reduced diarrhoea ( p 0.05). At 63 days of age the piglets subjected to LZnOE+DF treatment had lower diarrhoea than the pigs subjected to LZnOE treatment but higher than the ZnO and the ZnO+DF groups. Final weight and incidence of diarrhoea of pigs receiving LZnOE was worse than ZnO. LZnOE associated with DF provided the same final weight of piglets from the ZnO group.(AU)

Evaporative cooling system for gestating and lactating sows: a systematic review / Sistema de resfriamento evaporativo para porcas gestantes e lactantes: uma revisão sistemática

Climatic characteristics of the production sites of pigs influence the yield of the system, with breeding sows being a category extremely sensitive to high temperatures, especially when their upper critical temperature is reached. This review evaluated the effects of the evaporative cooling system on environmental, physiological and performance parameters in breeding sows. By means of this review, a bibliographic search was performed using the following keywords: sow; swine; gilt and pig combined individually with the expression evaporative cooling. A total of 11 papers met the prerequisites determined to compose the systematic review and the studies involved gestating and lactating sows maintained in environments that presented ambient temperatures between 21.5 and 34.8 °C and relative humidity between 32.2 and 84.2%. The evaporative cooling system was used in order to cool the macro or micro environment. It can be concluded that the use of evaporative cooling system promotes increase in feed intake per lactating sow, decrease in weight loss in lactation, increase of weight of piglets at weaning, temperature reduction of the barns and decrease of the respiratory rate of the sows. For gestating sows, no changes in reproductive performance were reported.(AU)

As características climáticas dos locais de produção de suínos influenciam na produtividade do sistema, sendo as fêmeas em reprodução uma categoria extremamente sensível a elevadas temperaturas, principalmente, quando é atingida sua temperatura critica superior. Por meio desta revisão, avaliou-se os efeitos do sistema de resfriamento evaporativo sobre parâmetros ambientais, fisiológicos e de desempenho em fêmeas suínas em reprodução. Uma pesquisa bibliográfica foi realizada utilizando as palavras-chave: sow; swine; gilt e pig combinadas individualmente com a expressão evaporative cooling. Um total de 11 artigos atendeu aos pré-requisitos determinados para compor a revisão sistemática, sendo que os estudos envolveram fêmeas gestantes e lactantes mantidas em ambientes que apresentaram temperaturas entre 21,5 e 34,8 °C, e umidade relativa entre 32,2 e 84,2%. O sistema de resfriamento evaporativo foi usado de forma a resfriar o macro ou micro ambiente. Pode-se concluir que o uso do sistema de resfriamento evaporativo promove aumento do consumo de ração para porcas em lactação, diminuição da perda de peso na lactação, aumento do peso dos leitões ao desmame, redução da temperatura dos galpões e diminuição da frequência respiratória das porcas. Para porcas gestantes, não foram encontradas alterações no desempenho reprodutivo.(AU)

Thermo-acoustic environment of a pig farm facility with different superimposed bed materials

The objective of this work was to compare different bedding materials in swine production systems by evaluating noise and thermal environment indexes. The experiment was performed during June and July, in the finishing phase, in a pig farm facility using superimposed beds. Three treatments were compared: superimposed beds comprised of shavings + sugarcane bagasse (S + B), superimposed bed comprised of sugarcane bagasse (BAG) and superimposed bed comprised of shavings (SHA); there was a concrete floor underneath all beds. Thermal comfort was evaluated by means of the black globe temperature (BGTI), temperature humidity index (THI), thermal radiation charge (TRC) and enthalpy (h) of the environment. The average noise level (dB) was also calculated. Significant differences between the BGHI means were observed between the evaluated treatments. The highest BGHI values occurred for treatment (S + B) in most time periods in relation to the other treatments. The lowest BGHI values were observed in the morning and evening, while the highest values occurred between 11:00 am and 03:00 pm. There was no significant difference between the treatments for the enthalpy values. The highest noise values were observed in treatment (SHA). However, in all treatments, noise remained below the levels recommended by the norm (NR- 15). The system with superimposed beds comprised by shavings provided highest thermal comfort for the animals in the finishing phase.(AU)

Thermo-acoustic environment of a pig farm facility with different superimposed bed materials

The objective of this work was to compare different bedding materials in swine production systems by evaluating noise and thermal environment indexes. The experiment was performed during June and July, in the finishing phase, in a pig farm facility using superimposed beds. Three treatments were compared: superimposed beds comprised of shavings + sugarcane bagasse (S + B), superimposed bed comprised of sugarcane bagasse (BAG) and superimposed bed comprised of shavings (SHA); there was a concrete floor underneath all beds. Thermal comfort was evaluated by means of the black globe temperature (BGTI), temperature humidity index (THI), thermal radiation charge (TRC) and enthalpy (h) of the environment. The average noise level (dB) was also calculated. Significant differences between the BGHI means were observed between the evaluated treatments. The highest BGHI values occurred for treatment (S + B) in most time periods in relation to the other treatments. The lowest BGHI values were observed in the morning and evening, while the highest values occurred between 11:00 am and 03:00 pm. There was no significant difference between the treatments for the enthalpy values. The highest noise values were observed in treatment (SHA). However, in all treatments, noise remained below the levels recommended by the norm (NR- 15). The system with superimposed beds comprised by shavings provided highest thermal comfort for the animals in the finishing phase.

Behavioral and physiological responses of different genetic lines of free-range broiler raised on a semi-intensive system

The aim of the study was evaluate the ability of adaptation of seven different genetic lines of free-range broilers to a semi-intensive raising system. Four hundred and twenty chicks of the Pescoço Pelado (PP), Carijó (CG), Colorpak (CPK), Tricolor (TRC), Caboclo (CBC), Gigante Negro (GNG) and Pesadão Vermelho (PS) genetic groups were used. At 28 days of age the birds were allowed access the paddocks and after three days of adaptation the monitoring of the animals has started, being performed behavioral visual observations from 07:00 to 17:00. Cloacal temperature (CT) and respiratory rate (RR) were collected once a week. The environment was monitored considering the temperature, relative humidity and black globe temperature at various points of the paddocks and the shed. The physiological variables were evaluated using a randomized complete block design with a split plot arrangement. Behavioral variables were analyzed using nonparametric Friedman test. Birds of Carijó and Colorpak genetic line presented greater RR, 34.6 mov/min and 36.0 mov/min respectively, compared to the birds of the Caboclo and Gigante Negro genetic line, 29.0 mov/min and 28.4 mov/min respectively. The average values of RR and CT for all genetic lines were higher in the afternoon. At 7:00 and 17:00 the foraging behavior was more intense. The Caboclo and Gigante Negro genetic line were those that stood out in the behavior of foraging, consequently, they are more able to adapt to the semi-intensive raising system.(AU)

Behavioral and physiological responses of different genetic lines of free-range broiler raised on a semi-intensive system

The aim of the study was evaluate the ability of adaptation of seven different genetic lines of free-range broilers to a semi-intensive raising system. Four hundred and twenty chicks of the Pescoço Pelado (PP), Carijó (CG), Colorpak (CPK), Tricolor (TRC), Caboclo (CBC), Gigante Negro (GNG) and Pesadão Vermelho (PS) genetic groups were used. At 28 days of age the birds were allowed access the paddocks and after three days of adaptation the monitoring of the animals has started, being performed behavioral visual observations from 07:00 to 17:00. Cloacal temperature (CT) and respiratory rate (RR) were collected once a week. The environment was monitored considering the temperature, relative humidity and black globe temperature at various points of the paddocks and the shed. The physiological variables were evaluated using a randomized complete block design with a split plot arrangement. Behavioral variables were analyzed using nonparametric Friedman test. Birds of Carijó and Colorpak genetic line presented greater RR, 34.6 mov/min and 36.0 mov/min respectively, compared to the birds of the Caboclo and Gigante Negro genetic line, 29.0 mov/min and 28.4 mov/min respectively. The average values of RR and CT for all genetic lines were higher in the afternoon. At 7:00 and 17:00 the foraging behavior was more intense. The Caboclo and Gigante Negro genetic line were those that stood out in the behavior of foraging, consequently, they are more able to adapt to the semi-intensive raising system.

Performance and behavior of pigs in finish phase subject to different programs of lighting / Desempenho e comportamento de suínos em fase de terminação submetidos a diferentes programas de luz

The aim of this study was to evaluate the use of lighting programs on performance, plasma concentration of melatonin and behavior of finishing pigs. The experiment was conducted in the pig farming sector UFLA, using 32 pigs in the finishing phase, for 48 days. The animals were housed in groups of two in each pen (experimental unit), distributed in a randomized block design, according to the initial weight. Four light periods were used (treatments): T1: natural light (LN); T2: 15 hours of light and dark by day nine (15L: 9E); T3: 19 hours light per day (19L: 5E); T4: 23 hours of light per day (23L: 1D). The variables analyzed were the performance (average daily feed consumption, average daily gain weight and feed conversion), the plasma concentrations of melatonin and the behavior (drinking, sniffing, leisure and eating). The change in photoperiod did not affect performance or melatonin concentration in pigs. The behavioral variables "digging", "eating", "drinking", did not differ in any of the periods studied, but leisure behavior was more occurring to the pigs receiving 15 hours of light. The increase in photoperiod showed no significant changes in performance or behavior of the animals.(AU)

Objetivou-se com esse trabalho avaliar o uso de programas de luz sobre o desempenho, concentração plasmática de melatonina e comportamento de suínos em fase de terminação. O experimento foi conduzido no setor de suinocultura da UFLA, utilizando-se 32 suínos em fase de terminação, por 48 dias. Os animais foram alojados em grupos de dois em cada baia (unidade experimental), distribuídos em delineamento em blocos casualizados, de acordo com o peso inicial com quatro tratamentos e quatro blocos. Foram utilizados quatro programas de luz (tratamentos), sendo T1: luz natural (LN); T2: 15 horas de luz e nove de escuro por dia (15L: 9E); T3: 19 horas de luz por dia (19L: 5E); T4: 23 horas de luz por dia (23L: 1E). As variáveis analisadas foram o desempenho (consumo de ração médio diário, ganho de peso médio diário e conversão alimentar), concentração plasmática de melatonina e o comportamento (bebendo, fuçando, ócio e comendo). A alteração no fotoperíodo não alterou o desempenho ou a concentração plasmática de melatonina nos suínos. As variáveis comportamentais fuçando, comendo, bebendo, não diferiram em nenhum dos períodos estudados, porém o comportamento ócio foi mais ocorrente nos suínos que receberam 15 horas de luz. O aumento no fotoperíodo não permitiu expressivas alterações de desempenho ou de comportamento dos animais.(AU)

Performance and behavior of pigs in finish phase subject to different programs of lighting / Desempenho e comportamento de suínos em fase de terminação submetidos a diferentes programas de luz

The aim of this study was to evaluate the use of lighting programs on performance, plasma concentration of melatonin and behavior of finishing pigs. The experiment was conducted in the pig farming sector UFLA, using 32 pigs in the finishing phase, for 48 days. The animals were housed in groups of two in each pen (experimental unit), distributed in a randomized block design, according to the initial weight. Four light periods were used (treatments): T1: natural light (LN); T2: 15 hours of light and dark by day nine (15L: 9E); T3: 19 hours light per day (19L: 5E); T4: 23 hours of light per day (23L: 1D). The variables analyzed were the performance (average daily feed consumption, average daily gain weight and feed conversion), the plasma concentrations of melatonin and the behavior (drinking, sniffing, leisure and eating). The change in photoperiod did not affect performance or melatonin concentration in pigs. The behavioral variables "digging", "eating", "drinking", did not differ in any of the periods studied, but leisure behavior was more occurring to the pigs receiving 15 hours of light. The increase in photoperiod showed no significant changes in performance or behavior of the animals.

Objetivou-se com esse trabalho avaliar o uso de programas de luz sobre o desempenho, concentração plasmática de melatonina e comportamento de suínos em fase de terminação. O experimento foi conduzido no setor de suinocultura da UFLA, utilizando-se 32 suínos em fase de terminação, por 48 dias. Os animais foram alojados em grupos de dois em cada baia (unidade experimental), distribuídos em delineamento em blocos casualizados, de acordo com o peso inicial com quatro tratamentos e quatro blocos. Foram utilizados quatro programas de luz (tratamentos), sendo T1: luz natural (LN); T2: 15 horas de luz e nove de escuro por dia (15L: 9E); T3: 19 horas de luz por dia (19L: 5E); T4: 23 horas de luz por dia (23L: 1E). As variáveis analisadas foram o desempenho (consumo de ração médio diário, ganho de peso médio diário e conversão alimentar), concentração plasmática de melatonina e o comportamento (bebendo, fuçando, ócio e comendo). A alteração no fotoperíodo não alterou o desempenho ou a concentração plasmática de melatonina nos suínos. As variáveis comportamentais fuçando, comendo, bebendo, não diferiram em nenhum dos períodos estudados, porém o comportamento ócio foi mais ocorrente nos suínos que receberam 15 horas de luz. O aumento no fotoperíodo não permitiu expressivas alterações de desempenho ou de comportamento dos animais.

Performance, behaviour and physiological responses of finishing pigs under different lighting programs / Desempenho, comportamento e respostas fisiológicas de suínos em terminação submetidos a diferentes programas de luz

Technologies that improve productivity are essentials for competitiveness in the pork market. The consumer market is always requiring information about the technologies applied in swine production, mainly from the perspective of animal welfare. The aim of this study was to evaluate the influence of lighting on performance, behavioral and physiological characteristics in finishing pigs. Thirty-six pigs were distributed in a completely randomized design with three treatments and six replications. The animals were subjected to three light programs: natural light (NL), 16 hours of light and eight hours of dark (16L:8D) and 23 hours of light and one hour of dark (23L:1D) for 28 days. Daily feed intake (DFI), average daily gain (ADG) and feed conversion (FC) were evaluated. The physiological parameters evaluated were rectal temperature (RT), respiratory rate (RR) and surface temperature (ST). The behavioral standards observed were: standing, lying, eating, drinking, sniffing, interacting, sitting, urinating and defecating. The lighting programs did not affect animal performance. However, pigs that received 23L:1D, showed, in the afternoon, ST upper than others treatments. Providing supplemental light promoted the elevation of RR, also in the afternoon. The RT was not influenced by treatments. The extended light program altered the behavior of the animals, which animals were most active, especially at night. Anyway, there was no improvement or reduction of the performance with the use of different lighting programs for finishing pigs. (AU)

Ferramentas capazes de melhorar a produtividade são essenciais para a competitividade no mercado da carne suinícola. Cada vez mais, o mercado consumidor exige informações sobre as tecnologias aplicadas na produção, principalmente sob a ótica do bem-estar animal. Desse modo, objetivou-se avaliar a influência da iluminação sobre características de desempenho, comportamentais e fisiológicas de suínos em fase de terminação. Para isso, foram utilizados 36 suínos distribuídos em delineamento inteiramente ao acaso em três tratamentos com seis repetições. Os animais foram submetidos a três programas de luz: luz natural (LN), 16 horas de luz e oito horas de escuro (16L:8E) e 23 horas de luz e uma de escuro (23L:1E), durante 28 dias. Foi observado consumo de ração diário (CRD), ganho de peso diário (GPD) e conversão alimentar (CA). Os parâmetros fisiológicos avaliados foram temperatura retal (TR), frequência respiratória (FR) e temperatura superficial (TS). Os padrões comportamentais observados foram: em pé, deitado, comendo, bebendo, fuçando, interagindo, sentado, urinando e defecando. Os programas de iluminação utilizados não influenciaram o desempenho dos animais. Entretanto, os suínos que receberam 23L:1E, apresentaram, no período da tarde, maior TS. O fornecimento de luz suplementar promoveu a elevação da FR, também no período da tarde. A TR não foi influenciada pelos tratamentos. Os programas de iluminação estendida alteraram o comportamento dos animais, que ficaram mais ativos, principalmente durante a noite. De toda forma, não se verificou benefício ou malefício no uso de programas de luz quanto ao desempenho de suínos em terminação. (AU)

Performance, behaviour and physiological responses of finishing pigs under different lighting programs / Desempenho, comportamento e respostas fisiológicas de suínos em terminação submetidos a diferentes programas de luz

Technologies that improve productivity are essentials for competitiveness in the pork market. The consumer market is always requiring information about the technologies applied in swine production, mainly from the perspective of animal welfare. The aim of this study was to evaluate the influence of lighting on performance, behavioral and physiological characteristics in finishing pigs. Thirty-six pigs were distributed in a completely randomized design with three treatments and six replications. The animals were subjected to three light programs: natural light (NL), 16 hours of light and eight hours of dark (16L:8D) and 23 hours of light and one hour of dark (23L:1D) for 28 days. Daily feed intake (DFI), average daily gain (ADG) and feed conversion (FC) were evaluated. The physiological parameters evaluated were rectal temperature (RT), respiratory rate (RR) and surface temperature (ST). The behavioral standards observed were: standing, lying, eating, drinking, sniffing, interacting, sitting, urinating and defecating. The lighting programs did not affect animal performance. However, pigs that received 23L:1D, showed, in the afternoon, ST upper than others treatments. Providing supplemental light promoted the elevation of RR, also in the afternoon. The RT was not influenced by treatments. The extended light program altered the behavior of the animals, which animals were most active, especially at night. Anyway, there was no improvement or reduction of the performance with the use of different lighting programs for finishing pigs.

Ferramentas capazes de melhorar a produtividade são essenciais para a competitividade no mercado da carne suinícola. Cada vez mais, o mercado consumidor exige informações sobre as tecnologias aplicadas na produção, principalmente sob a ótica do bem-estar animal. Desse modo, objetivou-se avaliar a influência da iluminação sobre características de desempenho, comportamentais e fisiológicas de suínos em fase de terminação. Para isso, foram utilizados 36 suínos distribuídos em delineamento inteiramente ao acaso em três tratamentos com seis repetições. Os animais foram submetidos a três programas de luz: luz natural (LN), 16 horas de luz e oito horas de escuro (16L:8E) e 23 horas de luz e uma de escuro (23L:1E), durante 28 dias. Foi observado consumo de ração diário (CRD), ganho de peso diário (GPD) e conversão alimentar (CA). Os parâmetros fisiológicos avaliados foram temperatura retal (TR), frequência respiratória (FR) e temperatura superficial (TS). Os padrões comportamentais observados foram: em pé, deitado, comendo, bebendo, fuçando, interagindo, sentado, urinando e defecando. Os programas de iluminação utilizados não influenciaram o desempenho dos animais. Entretanto, os suínos que receberam 23L:1E, apresentaram, no período da tarde, maior TS. O fornecimento de luz suplementar promoveu a elevação da FR, também no período da tarde. A TR não foi influenciada pelos tratamentos. Os programas de iluminação estendida alteraram o comportamento dos animais, que ficaram mais ativos, principalmente durante a noite. De toda forma, não se verificou benefício ou malefício no uso de programas de luz quanto ao desempenho de suínos em terminação.

Balanço eletrolítico e redução da proteína bruta da ração sobreparâmetros fisiológicos e sanguíneos de frangos de corte no calor / Electrolyte balance and crude protein reduction in physiologic and blood parameters of broiler chickens in heat

Um experimento foi conduzido, objetivando-se avaliar o efeito do balanço eletrolítico (BER) e a redução da proteína bruta (PB) da ração sobre a frequência respiratória, temperatura cloacal, concentrações de Na+, K+, Cl- e ácido úrico em frangos de corte. Foram utilizados 800 pintos de corte, machos da linhagem Cobb, alojados em 20 boxes, distribuídos em delineamento inteiramente casualizado com quatro tratamentos, cinco repetições e 40 aves por unidade experimental. Os tratamentos foram: T1 - ração basal; T2 - ração corrigida para BER de 250 mEq kg-1; T3 - ração com redução de PB, sem correção de BER; T4 - ração com redução de PB corrigida para BER de 250 mEq kg-1. As condições ambientais evidenciaram que os animais estavam em estresse por calor. As aves que receberam rações com correção do BER apresentaram menores valores (p < 0,05) de frequência respiratória nas fases estudadas, assim como de temperatura cloacal, na fase de sete a 21 dias. Não houve variação (p > 0,05) da temperatura cloacal no período total. A redução da PB diminuiu (p < 0,05) a concentração de sódio no soro. Aos 42 dias houve influência (p < 0,05) da utilização do eletrólito sobre a concentração de sódio. A suplementação com eletrólitos melhorou a homeostase dos frangos em condições de estresse por calor.(AU)

An experiment was carried with the An experiment was carried with the objective of evaluating the effect of diet electrolyte balance (DEB) and crude protein (CP) reduction on respiratory rate, cloacal temperature and concentrations of Na+, K+, Cl- and uric acid of broiler chickens. Eight-hundred male Cobb broiler chickens were randomly allocated in 20 boxes, with four treatments and five replicates of 40 birds per experimental unity. The treatments were: T1 - basal diet; T2 - diet adjustment until DEB = 250 mEq kg-1; T3 - diet with reduction of CP and without adjustment of DEB; T4 - diet with reduction of CP and adjustment of DEB to 250 mEq kg-1. The thermal environment was not favorable during the experimental period. The birds that received diets with correction of electrolyte balance showed low values (p < 0.05) of respiratory rate in the phases studied, as well as of cloacal temperature in the phase between 7 and 21 days. Results of cloacal temperature in the total period were not affected (p > 0.05). Reduction of crude protein decreased (p < 0.05) the concentration of sodium in the serum. The use of electrolyte in the concentration of sodium was influenced (p > 0.05) at 42 days. The supplementation with electrolytes improved homeostasis of the broilers in heat stress conditions. (AU)

Balanço eletrolítico e redução da proteína bruta da ração sobreparâmetros fisiológicos e sanguíneos de frangos de corte no calor / Electrolyte balance and crude protein reduction in physiologic and blood parameters of broiler chickens in heat

Um experimento foi conduzido, objetivando-se avaliar o efeito do balanço eletrolítico (BER) e a redução da proteína bruta (PB) da ração sobre a frequência respiratória, temperatura cloacal, concentrações de Na+, K+, Cl- e ácido úrico em frangos de corte. Foram utilizados 800 pintos de corte, machos da linhagem Cobb, alojados em 20 boxes, distribuídos em delineamento inteiramente casualizado com quatro tratamentos, cinco repetições e 40 aves por unidade experimental. Os tratamentos foram: T1 - ração basal; T2 - ração corrigida para BER de 250 mEq kg-1; T3 - ração com redução de PB, sem correção de BER; T4 - ração com redução de PB corrigida para BER de 250 mEq kg-1. As condições ambientais evidenciaram que os animais estavam em estresse por calor. As aves que receberam rações com correção do BER apresentaram menores valores (p 0,05) da temperatura cloacal no período total. A redução da PB diminuiu (p < 0,05) a concentração de sódio no soro. Aos 42 dias houve influência (p < 0,05) da utilização do eletrólito sobre a concentração de sódio. A suplementação com eletrólitos melhorou a homeostase dos frangos em condições de estresse por calor.

An experiment was carried with the An experiment was carried with the objective of evaluating the effect of diet electrolyte balance (DEB) and crude protein (CP) reduction on respiratory rate, cloacal temperature and concentrations of Na+, K+, Cl- and uric acid of broiler chickens. Eight-hundred male Cobb broiler chickens were randomly allocated in 20 boxes, with four treatments and five replicates of 40 birds per experimental unity. The treatments were: T1 - basal diet; T2 - diet adjustment until DEB = 250 mEq kg-1; T3 - diet with reduction of CP and without adjustment of DEB; T4 - diet with reduction of CP and adjustment of DEB to 250 mEq kg-1. The thermal environment was not favorable during the experimental period. The birds that received diets with correction of electrolyte balance showed low values (p 0.05). Reduction of crude protein decreased (p 0.05) at 42 days. The supplementation with electrolytes improved homeostasis of the broilers in heat stress conditions.