Salmonella typhimurium vaccine to control a brazilian Salmonella heidelberg strain in broiler chickens / Vacina de Salmonella typhimurium para controlar cepa brasileira de Salmonella heidelberg em frangos de corte

Foodborne Salmonella infections in humans, which results from the consumption of contaminated poultry meat and eggs, are a major public health concern. Vaccination of animals against Salmonella is one strategy to prevent these infections and reduce the risks to public health. Live attenuated Salmonella enterica vaccines can confer protection against salmonellosis by inducing both cell-mediated and mucosal immune responses. This study assessed a live, attenuated Salmonella enterica Typhimurium (ST) vaccine in broiler chickens against a heterologous challenge with Salmonella Heidelberg (SH) by evaluating bacterial quantification, immune cells infiltration, and cytokine gene expression in the cecum. The treatments were: T1, non-vaccinated, non-challenged; T2, non-vaccinated, SH-challenged; T3, ST-vaccinated and SH-challenged. At 28 days of age, the ST-vaccinated group had significantly recovered reduction of SH in the crop (P<0,01) and cecum (P = 0,021) compared to the non-vaccinated SH-challenged group, with no significant changes (P˃0,05) in macrophages, T CD4+, or T CD8+ cells dynamics during the same period. Aerosol vaccination on the first day promoted greater interleukin-12 expression in the liver (P<0,05) and interleukin-10 expression and T CD8+ cells in the ileum 16 hours after housing. After prime-boosted oral immunization on the 13th day, the vaccinated group had greater expression of macrophages and T CD4+ cells in the liver (P<0,05) than the control group. Two doses of a live ST-attenuated vaccine promoted a partial cross-protective effect against SH strain UFPR1 challenge in broilers.

Infecções por Salmonella transmitidas por alimentos como consumo de carne de frango e ovos contaminados em seres humanos constituem um importante problema de saúde pública. A vacinação de animais contra Salmonella é uma estratégia para prevenir essas infecções e reduzir o risco para a saúde pública. As vacinas vivas atenuadas de Salmonella enterica podem conferir proteção contra a salmonelose, induzindo respostas imunológicas mediadas por células e em mucosas. Este estudo avaliou uma vacina viva e atenuada de Salmonella enterica Typhimurium (ST) em frangos de corte contra um desafio heterólogo com Salmonella Heidelberg (SH), avaliando a quantificação de Salmonella, infiltração de células imunes e a expressão de genes de citocinas no ceco. Os tratamentos foram: T1, não vacinado, não desafiado; T2, não vacinado, desafiado com SH; T3, ST-vacinado, desafiado com SH. Aos 28 dias de idade, o grupo vacinado com ST apresentou significativa redução de SH no papo (P<0,01) e no ceco (P = 0,021) comparado ao grupo T2-não vacinado SH-desafiado, sem alterações significativas na dinâmica celular de macrófagos, T CD4+ ou T CD8+ (P˃0,05) durante o mesmo período. A vacinação por aerossol no primeiro dia promoveu maior expressão de IL-12 no fígado (P<0,05), maior expressão de IL-10 e células T CD8+ no íleo, 16 horas após o alojamento. Após o reforço de imunização oral ao 13º dia, o grupo vacinado apresentou maior expressão de macrófagos e células T CD4+ no fígado (P<0,05) do que o grupo controle. Duas doses de uma vacina viva atenuada de ST promoveram um efeito de proteção cruzada parcial contra o desafio da cepa de Salmonella Heidelberg cepa UFPR1 em frangos de corte.

Salmonella typhimurium vaccine to control a brazilian Salmonella heidelberg strain in broiler chickens / Vacina de Salmonella typhimurium para controlar cepa brasileira de Salmonella heidelberg em frangos de corte

Foodborne Salmonella infections in humans, which results from the consumption of contaminated poultry meat and eggs, are a major public health concern. Vaccination of animals against Salmonella is one strategy to prevent these infections and reduce the risks to public health. Live attenuated Salmonella enterica vaccines can confer protection against salmonellosis by inducing both cell-mediated and mucosal immune responses. This study assessed a live, attenuated Salmonella enterica Typhimurium (ST) vaccine in broiler chickens against a heterologous challenge with Salmonella Heidelberg (SH) by evaluating bacterial quantification, immune cells infiltration, and cytokine gene expression in the cecum. The treatments were: T1, non-vaccinated, non-challenged; T2, non-vaccinated, SH-challenged; T3, ST-vaccinated and SH-challenged. At 28 days of age, the ST-vaccinated group had significantly recovered reduction of SH in the crop (P<0,01) and cecum (P = 0,021) compared to the non-vaccinated SH-challenged group, with no significant changes (P˃0,05) in macrophages, T CD4+, or T CD8+ cells dynamics during the same period. Aerosol vaccination on the first day promoted greater interleukin-12 expression in the liver (P<0,05) and interleukin-10 expression and T CD8+ cells in the ileum 16 hours after housing. After prime-boosted oral immunization on the 13th day, the vaccinated group had greater expression of macrophages and T CD4+ cells in the liver (P<0,05) than the control group. Two doses of a live ST-attenuated vaccine promoted a partial cross-protective effect against SH strain UFPR1 challenge in broilers.(AU)

Infecções por Salmonella transmitidas por alimentos como consumo de carne de frango e ovos contaminados em seres humanos constituem um importante problema de saúde pública. A vacinação de animais contra Salmonella é uma estratégia para prevenir essas infecções e reduzir o risco para a saúde pública. As vacinas vivas atenuadas de Salmonella enterica podem conferir proteção contra a salmonelose, induzindo respostas imunológicas mediadas por células e em mucosas. Este estudo avaliou uma vacina viva e atenuada de Salmonella enterica Typhimurium (ST) em frangos de corte contra um desafio heterólogo com Salmonella Heidelberg (SH), avaliando a quantificação de Salmonella, infiltração de células imunes e a expressão de genes de citocinas no ceco. Os tratamentos foram: T1, não vacinado, não desafiado; T2, não vacinado, desafiado com SH; T3, ST-vacinado, desafiado com SH. Aos 28 dias de idade, o grupo vacinado com ST apresentou significativa redução de SH no papo (P<0,01) e no ceco (P = 0,021) comparado ao grupo T2-não vacinado SH-desafiado, sem alterações significativas na dinâmica celular de macrófagos, T CD4+ ou T CD8+ (P˃0,05) durante o mesmo período. A vacinação por aerossol no primeiro dia promoveu maior expressão de IL-12 no fígado (P<0,05), maior expressão de IL-10 e células T CD8+ no íleo, 16 horas após o alojamento. Após o reforço de imunização oral ao 13º dia, o grupo vacinado apresentou maior expressão de macrófagos e células T CD4+ no fígado (P<0,05) do que o grupo controle. Duas doses de uma vacina viva atenuada de ST promoveram um efeito de proteção cruzada parcial contra o desafio da cepa de Salmonella Heidelberg cepa UFPR1 em frangos de corte.(AU)

Influence of covering reused broiler litter with plastic canvas on litter characteristics and bacteriology and the subsequent immunity and microbiology of broilers

In broiler production, the litter is reused for consecutives flocks, and it is treated during down time between flocks to reduce its microbial load. Although covering the litter with a plastic canvas is a common litter treatment in the field, there is little scientific information available on its efficacy. The aim of this study was to evaluate the effects of covering broiler litter with a plastic canvas for eight days on litter microbiological, physical, and chemical parameters, and on the intestinal microbiota and immunity of broilers. In the first trial, reused litter from a previous flock was distributed into three treatments, with six replicates each: L1 (negative control, litter free from Salmonella Enteritidis (SE) and Eimeria maxima (EM) and not covered), L2 (positive control, litter with SE and EM, and not covered), and L3 (litter with SE and EM, and covered with plastic canvas for eight days). Litter total bacteria, Enterobacteria, Lactobacillus, SE, and EM counts, and litter pH, temperature, moisture, and ammonia emission were determined on days 1 and 8. In the second trial, broilers were housed on those litters according to the treatments described above, and their intestinal microbiota, gut CD4+ and CD8+ lymphocytes and macrophages, and liver and intestinal pro-inflammatory interleukin (IFN-, IL-1 e IL-18) levels were evaluated on days 14 and 28. A significant reduction of litter bacterial populations was observed in the litter covered with plastic canvas. A significantly higher mRNA IFN- gene expression (12.5-fold) was observed in the jejunum and liver of broilers reared on the litter with Enterobacteria counts. No EM reduction was observed in the covered litter. Covering reused broiler litter with plastic canvas reduces initial litter bacterial load as a result of the interaction between physical and chemical parameters.

Influence of covering reused broiler litter with plastic canvas on litter characteristics and bacteriology and the subsequent immunity and microbiology of broilers

In broiler production, the litter is reused for consecutives flocks, and it is treated during down time between flocks to reduce its microbial load. Although covering the litter with a plastic canvas is a common litter treatment in the field, there is little scientific information available on its efficacy. The aim of this study was to evaluate the effects of covering broiler litter with a plastic canvas for eight days on litter microbiological, physical, and chemical parameters, and on the intestinal microbiota and immunity of broilers. In the first trial, reused litter from a previous flock was distributed into three treatments, with six replicates each: L1 (negative control, litter free from Salmonella Enteritidis (SE) and Eimeria maxima (EM) and not covered), L2 (positive control, litter with SE and EM, and not covered), and L3 (litter with SE and EM, and covered with plastic canvas for eight days). Litter total bacteria, Enterobacteria, Lactobacillus, SE, and EM counts, and litter pH, temperature, moisture, and ammonia emission were determined on days 1 and 8. In the second trial, broilers were housed on those litters according to the treatments described above, and their intestinal microbiota, gut CD4+ and CD8+ lymphocytes and macrophages, and liver and intestinal pro-inflammatory interleukin (IFN-, IL-1 e IL-18) levels were evaluated on days 14 and 28. A significant reduction of litter bacterial populations was observed in the litter covered with plastic canvas. A significantly higher mRNA IFN- gene expression (12.5-fold) was observed in the jejunum and liver of broilers reared on the litter with Enterobacteria counts. No EM reduction was observed in the covered litter. Covering reused broiler litter with plastic canvas reduces initial litter bacterial load as a result of the interaction between physical and chemical parameters.(AU)

Effect of Broiler Breeder Age and Glutamine Supplementation on the Development of the Intestinal Mucosa of 7-Day-Old Chicks

The aim of this study was to evaluate the possible effects of glutamine and broiler breeder age on the development of intestinal mucosa in broiler chicks during first week of age. For this purpose, 32 one-day-old broiler chicks were distributed according to a completely randomized experimental design in a 2 x 2 factorial arrangement. Treatments consisted of two broiler breeder ages (30 and 60 weeks) and two dietary glutamine supplementation levels (0% and 1%). The morphological development of intestinal mucosa, particularly villus height and crypt depth, was evaluated. The results showed that the supplementation with 1% of glutamine influenced the development of villus height in the duodenum (p=0.009), jejunum (p = 0.006), and ileum (p = 0.001), as well as crypt depth in the jejunum (p = 0.037) of 7-day-old broilers. These results suggest that the presence of glutamine influenced the development of intestinal mucosa during the first week of age, when these tissues are highly influenced by dietary components, especially by trophic agents. The results show that broiler breeder age (30 or 60 weeks) did not influence the evaluated parameters.

Effect of broiler breeder age on the intestinal mucosa development of the embryos at 20 days of incubation

This study investigated the effect of broiler breeder age on the morphological development of the small intestine broiler embryos (villus height, crypt depth, microvillus height, and villus density) at 20 day of incubation. Eggs obtained from 30- and 60-wk-old broiler breeders were used. The results showed that embryos from older broiler breeders presented longer villi in the duodenum, jejunum, and ileum compared with younger broiler breeders. In addition, embryos from older broiler breeders presented deeper crypts in the jejunum and ileum, longer microvilli in jejunal enterocytes, and lower villus density (microvillus number/mm2) in the duodenum and ileum than younger breeders. These results suggest that breeder age influences the gut mucosa development of broiler embryos. Embryos from older broiler breeder showed greater development of the small intestine mucosa than those from younger broiler breeder.

Effect of broiler breeder age on the intestinal mucosa development of the embryos at 20 days of incubation

This study investigated the effect of broiler breeder age on the morphological development of the small intestine broiler embryos (villus height, crypt depth, microvillus height, and villus density) at 20 day of incubation. Eggs obtained from 30- and 60-wk-old broiler breeders were used. The results showed that embryos from older broiler breeders presented longer villi in the duodenum, jejunum, and ileum compared with younger broiler breeders. In addition, embryos from older broiler breeders presented deeper crypts in the jejunum and ileum, longer microvilli in jejunal enterocytes, and lower villus density (microvillus number/mm2) in the duodenum and ileum than younger breeders. These results suggest that breeder age influences the gut mucosa development of broiler embryos. Embryos from older broiler breeder showed greater development of the small intestine mucosa than those from younger broiler breeder.(AU)

Effect of Broiler Breeder Age and Glutamine Supplementation on the Development of the Intestinal Mucosa of 7-Day-Old Chicks

The aim of this study was to evaluate the possible effects of glutamine and broiler breeder age on the development of intestinal mucosa in broiler chicks during first week of age. For this purpose, 32 one-day-old broiler chicks were distributed according to a completely randomized experimental design in a 2 x 2 factorial arrangement. Treatments consisted of two broiler breeder ages (30 and 60 weeks) and two dietary glutamine supplementation levels (0% and 1%). The morphological development of intestinal mucosa, particularly villus height and crypt depth, was evaluated. The results showed that the supplementation with 1% of glutamine influenced the development of villus height in the duodenum (p=0.009), jejunum (p = 0.006), and ileum (p = 0.001), as well as crypt depth in the jejunum (p = 0.037) of 7-day-old broilers. These results suggest that the presence of glutamine influenced the development of intestinal mucosa during the first week of age, when these tissues are highly influenced by dietary components, especially by trophic agents. The results show that broiler breeder age (30 or 60 weeks) did not influence the evaluated parameters.(AU)

Evaluation of yeast cell wall on the performance of broiles fed diets with or without mycotoxins

This experiment aimed at evaluating the effects of the interactions between aflatoxin (500 or 250 ppb) and ochratoxin (500 or 250 ppb), and the possible benefits of adding yeast cell wall to prevent the effects of these mycotoxins in broiler chickens. Relative organ weight gain and live performance were evaluated at 21 and 42 days of age. Results indicated that at the levels of mycotoxins included in the experimental diets, ochratoxin reduced feed intake and body weight gain, and aflatoxin only affect feed intake of 21-day-old birds. No interaction was observed between aflatoxin and ochratoxin at the levels used in experimental study. Yeast cell wall did not significantly reduced the deleterious effects of ochratoxins. No significant differences were observed in relative organ weight gain. Yeast cell wall improved feed conversion ratio when birds were fed either contaminated or non-contaminated feeds.

Evaluation of yeast cell wall on the performance of broiles fed diets with or without mycotoxins

This experiment aimed at evaluating the effects of the interactions between aflatoxin (500 or 250 ppb) and ochratoxin (500 or 250 ppb), and the possible benefits of adding yeast cell wall to prevent the effects of these mycotoxins in broiler chickens. Relative organ weight gain and live performance were evaluated at 21 and 42 days of age. Results indicated that at the levels of mycotoxins included in the experimental diets, ochratoxin reduced feed intake and body weight gain, and aflatoxin only affect feed intake of 21-day-old birds. No interaction was observed between aflatoxin and ochratoxin at the levels used in experimental study. Yeast cell wall did not significantly reduced the deleterious effects of ochratoxins. No significant differences were observed in relative organ weight gain. Yeast cell wall improved feed conversion ratio when birds were fed either contaminated or non-contaminated feeds.

Effect of energy levels of diets formulated on total or digestible amino acid basis on broiler performance

This study was conducted to evaluate the performance and carcass and breast yields of broilers fed two different energy levels (3,200 or 2,900 kcal ME/kg) and two ways of expressing amino acid requirements (total - TAA or digestible - DAA) between 21 and 42 days of age. The results showed that broilers fed the diet containing 3,200 kcal ME/kg had higher weight gain (P=0.015), better feed conversion (P=0.001), and higher abdominal fat deposition (P=0.001) as compared to those fed the diet containing 2,900 kcal ME/kg. Diets formulated on DAA basis promoted higher weight gain (P=0.043), better feed conversion (P=0.010) and better conversion of ME intake into weight gain (P=0.007) as compared to those formulated on TAA basis. The results of this study suggest that formulation based on DAA is necessary if the diets contain protein sources that are not reliable in terms of amino acid digestibility. The response to formulation based on DAA was minimized when birds received the low energy level diet (2,900 kcal ME/kg).

Effect of broiler breeder age on pancreas enzymes activity and digestive tract weight of embryos and chicks

A study was carried out to evaluate the effect of broiler breeder age on the development of the digestive tract of embryos and chicks. Fertilized eggs Cobb from 30 and 60 week-old broiler breeder was utilized in this experiment. The results showed that eggs from older (60 weeks of age) broiler breeders were heavier (p = 0.001) than those from younger (30 weeks of age) broiler breeder. In addition, older broiler breeder had larger (p = 0.001) embryos showing a higher yolk sac (p = 0.001) and higher gastrointestinal tract relative weight (p = 0.007) than those from younger broiler breeder. The activities of pancreatic lipase and trypsin enzymes were also higher in embryos from older broiler breeder than those from younger broiler breeder (p = 0.001 and p = 0.002, respectively). Nevertheless, at the seven-day-old chick, no difference was observed in relative weight of gastrointestinal tract or pancreatic lipase and trypsin activities between older and younger broiler breeder age. However chicks from older broiler breeder were heavier than those from younger broiler breeder (p = 0.005). These data suggest that broiler breeder age is important on grower and on the development of the gastrointestinal tract and pancreatic lipase and trypsin activities of embryo. However after one week of hatching the morphophysiological difference disappear.

Effect of broiler breeder age on pancreas enzymes activity and digestive tract weight of embryos and chicks

A study was carried out to evaluate the effect of broiler breeder age on the development of the digestive tract of embryos and chicks. Fertilized eggs Cobb from 30 and 60 week-old broiler breeder was utilized in this experiment. The results showed that eggs from older (60 weeks of age) broiler breeders were heavier (p = 0.001) than those from younger (30 weeks of age) broiler breeder. In addition, older broiler breeder had larger (p = 0.001) embryos showing a higher yolk sac (p = 0.001) and higher gastrointestinal tract relative weight (p = 0.007) than those from younger broiler breeder. The activities of pancreatic lipase and trypsin enzymes were also higher in embryos from older broiler breeder than those from younger broiler breeder (p = 0.001 and p = 0.002, respectively). Nevertheless, at the seven-day-old chick, no difference was observed in relative weight of gastrointestinal tract or pancreatic lipase and trypsin activities between older and younger broiler breeder age. However chicks from older broiler breeder were heavier than those from younger broiler breeder (p = 0.005). These data suggest that broiler breeder age is important on grower and on the development of the gastrointestinal tract and pancreatic lipase and trypsin activities of embryo. However after one week of hatching the morphophysiological difference disappear.

Effect of energy levels of diets formulated on total or digestible amino acid basis on broiler performance

This study was conducted to evaluate the performance and carcass and breast yields of broilers fed two different energy levels (3,200 or 2,900 kcal ME/kg) and two ways of expressing amino acid requirements (total - TAA or digestible - DAA) between 21 and 42 days of age. The results showed that broilers fed the diet containing 3,200 kcal ME/kg had higher weight gain (P=0.015), better feed conversion (P=0.001), and higher abdominal fat deposition (P=0.001) as compared to those fed the diet containing 2,900 kcal ME/kg. Diets formulated on DAA basis promoted higher weight gain (P=0.043), better feed conversion (P=0.010) and better conversion of ME intake into weight gain (P=0.007) as compared to those formulated on TAA basis. The results of this study suggest that formulation based on DAA is necessary if the diets contain protein sources that are not reliable in terms of amino acid digestibility. The response to formulation based on DAA was minimized when birds received the low energy level diet (2,900 kcal ME/kg).

Efeitos de Produto de Exclusão Competitiva na Prevenção dos Efeitos Tóxicos da Ocratoxina A em Frangos

This experiment aimed at evaluating the action of competitive exclusion (CE) on the effects of ochratoxin A (OA). Birds fed 2ppm OA in the diet had significant lower feed intake, weight gain, and feed conversion than birds not exposed to OA in the diet. The use of CE on the first day of age did not minimize these effects nor the performance parameters studied. Birds fed OA has lower vaccinal titers of Newcastle disease virus, showing the interference of this mycotoxin on the humoral immune response of broilers. CE did not interfere in the humoral immune response of broilers vaccinated for Newcastle disease. OA and CE did not influence villus height, crypt depth, nor villus:crypt ratio in seven-day-old birds as compared to control broilers of the same age.

Esse experimento foi realizado com o objetivo de avaliar a ação de produto de exclusão competitiva (EC) sobre os efeitos da ocratoxina A (OA). As aves alimentadas com 2 ppm de OA na dieta reduziram significativamente o consumo de ração e ganho de peso, além de apresentarem pior conversão alimentar quando comparadas às aves não expostas à OA na dieta. O emprego da EC no primeiro dia de vida não minimizou esses efeitos, bem como não afetou os parâmetros zootécnicos estudados. Aves alimentadas com OA apresentaram diminuição nos títulos vacinais contra o vírus da doença de Newcastle, evidenciando-se assim a interferência dessa micotoxina na resposta imune humoral de frangos de corte. De outra forma, a EC não interferiu na resposta imune humoral de frangos de corte vacinados contra a doença de Newcastle. Tanto a AO como a EC não alteraram os dados de altura de vilo, profundidade de cripta e relação vilo:cripta nas aves aos sete dias de idade quando comparados àqueles do grupo controle na mesma idade

Utilização de Prebióticos, Probióticos ou Simbióticos em Dietas para Frangos

This study was carried out with the objective to test the substitution of antibiotics by prebiotics, probiotics or symbiotics in broiler chickens diet up to 45 days of age. Day-old chicks (n=750) were divided in five treatments, as follow: T1-no additives, T2-antibiotics (Olaquindoxâ e Nitrovinâ ), T3-prebiotic (0.2% de S. cerevisiae cell wall), T4-probiotics (300ppm B.subtilis) and T5-symbiotic (T3+ T4). The performance of broilers up to 45 days of age was influenced by treatments, with better weight gain observed in the birds fed with symbiotics, followed by antibiotcs, prebiotics and probiotics. The worse body weight gain was obtained by the broilers whose diet was not supplemented by any additive. During this period, feed conversion was also affected depending on the additive used, since the birds not supplemented showed the worse results when compared to the birds of the other treatments. The findings of this study suggest that the substitution of antibiotics by symbiotics in broiler chicken diets is an alternative to poultry industry, since no negative effect was found on performance. However, the total absence of additives in the diets worsened the broiler chicken performance.

Foi investigado o efeito da substituição de antibióticos por prebiótico, probiótico e simbiótico em dietas para frangos de corte de 1 a 45 dias de idade. Foram utilizados 750 pintos de 1 dia de idade, distribuídos em cinco tratamentos, sendo: T1-sem aditivos, T2-antibiótico (Olaquindox FONT FACE=Symbol>â /FONT> e Nitrovin FONT FACE=Symbol>â /FONT> ), T3-prebiótico (0,2% de parede celular de S. cerevisiae), T4-probiótico (300 ppm de B. subtilis) e T5-simbiótico (T3 + T4). O desempenho dos frangos de 1-45 dias de idade foi influenciado pelos diferentes tratamentos, sendo o melhor ganho de peso observado em aves que receberam o simbiótico, seguido daquelas com antibiótico, prebiótico e probiótico. O pior ganho de peso foi observado nas aves que não receberam qualquer tipo de aditivo na dieta. A conversão alimentar, no período de 1 a 45 dias de idade, também foi influenciada pelo tipo de aditivo. As aves que não receberam suplementação apresentaram pior conversão alimentar quando comparadas com as aves dos demais tratamentos. Os resultados deste experimento permitem concluir que a substituição de antibióticos por simbióticos na ração de frangos é uma alternativa viável, pois não compromete o desempenho das aves, contudo a ausência de aditivos na dieta piora o desempenho das mesmas.

Utilização de Prebióticos, Probióticos ou Simbióticos em Dietas para Frangos

This study was carried out with the objective to test the substitution of antibiotics by prebiotics, probiotics or symbiotics in broiler chickens diet up to 45 days of age. Day-old chicks (n=750) were divided in five treatments, as follow: T1-no additives, T2-antibiotics (Olaquindoxâ e Nitrovinâ ), T3-prebiotic (0.2% de S. cerevisiae cell wall), T4-probiotics (300ppm B.subtilis) and T5-symbiotic (T3+ T4). The performance of broilers up to 45 days of age was influenced by treatments, with better weight gain observed in the birds fed with symbiotics, followed by antibiotcs, prebiotics and probiotics. The worse body weight gain was obtained by the broilers whose diet was not supplemented by any additive. During this period, feed conversion was also affected depending on the additive used, since the birds not supplemented showed the worse results when compared to the birds of the other treatments. The findings of this study suggest that the substitution of antibiotics by symbiotics in broiler chicken diets is an alternative to poultry industry, since no negative effect was found on performance. However, the total absence of additives in the diets worsened the broiler chicken performance.

Foi investigado o efeito da substituição de antibióticos por prebiótico, probiótico e simbiótico em dietas para frangos de corte de 1 a 45 dias de idade. Foram utilizados 750 pintos de 1 dia de idade, distribuídos em cinco tratamentos, sendo: T1-sem aditivos, T2-antibiótico (Olaquindox FONT FACE=Symbol>â /FONT> e Nitrovin FONT FACE=Symbol>â /FONT> ), T3-prebiótico (0,2% de parede celular de S. cerevisiae), T4-probiótico (300 ppm de B. subtilis) e T5-simbiótico (T3 + T4). O desempenho dos frangos de 1-45 dias de idade foi influenciado pelos diferentes tratamentos, sendo o melhor ganho de peso observado em aves que receberam o simbiótico, seguido daquelas com antibiótico, prebiótico e probiótico. O pior ganho de peso foi observado nas aves que não receberam qualquer tipo de aditivo na dieta. A conversão alimentar, no período de 1 a 45 dias de idade, também foi influenciada pelo tipo de aditivo. As aves que não receberam suplementação apresentaram pior conversão alimentar quando comparadas com as aves dos demais tratamentos. Os resultados deste experimento permitem concluir que a substituição de antibióticos por simbióticos na ração de frangos é uma alternativa viável, pois não compromete o desempenho das aves, contudo a ausência de aditivos na dieta piora o desempenho das mesmas.

Efeitos de Produto de Exclusão Competitiva na Prevenção dos Efeitos Tóxicos da Ocratoxina A em Frangos

This experiment aimed at evaluating the action of competitive exclusion (CE) on the effects of ochratoxin A (OA). Birds fed 2ppm OA in the diet had significant lower feed intake, weight gain, and feed conversion than birds not exposed to OA in the diet. The use of CE on the first day of age did not minimize these effects nor the performance parameters studied. Birds fed OA has lower vaccinal titers of Newcastle disease virus, showing the interference of this mycotoxin on the humoral immune response of broilers. CE did not interfere in the humoral immune response of broilers vaccinated for Newcastle disease. OA and CE did not influence villus height, crypt depth, nor villus:crypt ratio in seven-day-old birds as compared to control broilers of the same age.

Esse experimento foi realizado com o objetivo de avaliar a ação de produto de exclusão competitiva (EC) sobre os efeitos da ocratoxina A (OA). As aves alimentadas com 2 ppm de OA na dieta reduziram significativamente o consumo de ração e ganho de peso, além de apresentarem pior conversão alimentar quando comparadas às aves não expostas à OA na dieta. O emprego da EC no primeiro dia de vida não minimizou esses efeitos, bem como não afetou os parâmetros zootécnicos estudados. Aves alimentadas com OA apresentaram diminuição nos títulos vacinais contra o vírus da doença de Newcastle, evidenciando-se assim a interferência dessa micotoxina na resposta imune humoral de frangos de corte. De outra forma, a EC não interferiu na resposta imune humoral de frangos de corte vacinados contra a doença de Newcastle. Tanto a AO como a EC não alteraram os dados de altura de vilo, profundidade de cripta e relação vilo:cripta nas aves aos sete dias de idade quando comparados àqueles do grupo controle na mesma idade

Influência da infusão transcervical de plasma seminal ou de estrógeno na concepção, no ciclo estral e na ovulação de porcas / Influence of transcervical infusion of seminal plasma or oestrogen on conception, oestrus cycle and ovulation in sows

O objetivo deste trabalho foi o de avaliar o desempenho de 211 porcas da linhagem Camborough 22 Marca Registrada, de diferentes ordens de parto, submetidas à infusão transcervical de plasma seminal ou de estrógeno no início do estro. Após o desmame, elas foram examinadas duas vezes ao dia para a detecção do estro, na presença de um macho sexualmente maduro, e da ovulação, com auxílio da ultrasonografia transcutânea. No início do estro as fêmeas receberam aleatoriamente uma infusão transcervical de plasma seminal, de estrógeno ou permaneceram como grupo-controle. Todas as fêmeas foram inseminadas no turno seguinte à detecção do estro, recebendo no máximo três inseminações com intervalos de 8 a 16h. No grupo-controle as fêmeas de primeiro parto ovularam mais precocemente que as fêmeas com maior número de partos (P<0,05). Os tratamentos não influenciaram a duração do estro e o momento da ovulação. O número total de leitões nascidos não diferiu entre os tratamentos. (AU)

The aim of this work was to evaluate the reproductive performance of sows from different parities after transcervical infusion of seminal plasma or oestrogen at onset of oestrus. Two hundred and eleven Camborough 22â sows were used and classified according to the parity. Oestrus detection was performed twice daily after weaning in the presence of a mature boar. The ovulation was detected with a transcutaneous ultrasonography. At onset of oestrus the sows were randomly infused with seminal plasma, oestrogen or not infused (control group). All the females were inseminated in a maximum of three times into 8 and 16 hours intervals. In the control group first parity females ovulated earlier than second or higher parity females (P<0.05). Treatments did not influence neither oestrus length nor ovulation time. Litter size was not different among treatments. (AU)

Electrolytic Balance in Broiler Chicks During the First Week of Age

Two experiments were carried out using 712 day-old chicks to evaluate the electrolytic balance (Na+K-Cl) in pre-starter (1-7 days) broiler diets. The feed, based on corn and soybean meal with 21.5 % protein and 2,900 kcal ME/kg, was offered ad libitum. In experiment I, K level was fixed, and Na and Cl levels were changed, using four 4 treatments and eight replicates of 16 birds. In experiment II, increasing levels of Na and K were used, with a total of four treatments and five repetitions of 10 birds. In both experiments, the dietary electrolytic balance was 40; 140; 240 and 340 mEq/kg. Electrolytic balance caused a quadratic effect on weight gain and feed:gain ratio, and a linear increase in feed intake when the electrolytic balance was increased by the single supplementation of Na, indicating that this ion stimulates feed intake of birds at this stage. However, feed intake was maximum for 202 mEq/kg, when K and Na levels were concurrently increased in the diet, indicating that there is a limit over which feed intake is depressed as a function of excessive K. The ideal electrolytic dietary balance was between 246 and 277 mEq/kg, obtained by the manipulation of Na and Cl levels.

Foram conduzidos dois experimentos, utilizando-se 712 pintos de corte para avaliar o efeito do balanço eletrolítico (Na+K-Cl) em rações pré-iniciais (1-7 dias) de frangos de corte. As rações à base de milho e farelo de soja, com 21,5 % de proteína e 2.900 kcal EM/kg, foram oferecidas à vontade. No experimento I, o nível de K foi fixado e os níveis de Na e Cl foram manipulados, em 4 tratamentos com 8 repetições de 16 aves cada. No experimento II, níveis mais elevados de Na e K foram usados, com 4 tratamentos e 5 repetições de 10 aves cada. Em ambos os experimentos, os balanços eletrolíticos foram de 40; 140; 240 e 340 mEq/kg de ração. O balanço eletrolítico causou um efeito quadrático no ganho de peso e na conversão alimentar e um aumento linear no consumo de alimento quando o balanço eletrolítico foi aumentado pela suplementação de Na, indicando que esse íon estimula o consumo de alimento das aves nesse período. Porém, o consumo de alimento foi máximo em 202 mEq/kg, quando os níveis de K e Na foram simultaneamente aumentados na dieta, indicando que o limite superior de consumo de alimento é deprimido em função do K em excesso. O balanço eletrolítico ideal foi entre 246 e 277 mEq/kg obtidos pela manipulação dos níveis de Na e Cl.