José Otávio Berti Sorbara - Academia.edu (original) (raw)

Papers by José Otávio Berti Sorbara

Research paper thumbnail of Effects of different carbohydrates in the feed of newly hatched chicks on performance and organs allometric growth

Research paper thumbnail of Probióticos não alteram os índices zootécnicos e a estrutura da comunidade microbiana intestinal de frangos de corte

Research paper thumbnail of Effects of different protein sources in the feed of newly hatched on broiler performance

Research paper thumbnail of Oxidative stability of thigh meat from broilers fed oxidized poultry offal fat

Research paper thumbnail of Efeito do peso de pintos de corte ao alojamento sobre o desempenho de frangos até 42 dias

Research paper thumbnail of Energy and nutrient utilisation of broilers fed soybean meal from two different Brazilian production areas with an exogenous protease

Animal Feed Science and Technology, 2016

A study was conducted to evaluate the effects of an exogenous protease added to diets having soyb... more A study was conducted to evaluate the effects of an exogenous protease added to diets having soybean meal (SBM) from two geographic areas in Brazil (South or North). Evaluation was conducted on energy utilisation and nutrient digestibility using 224 slow feathering Cobb × Cobb 500 male broilers. Birds were fed a common starter diet to d 15. Semi-purified experimental diets containing 555 g/kg SBM and 408 g/kg maize starch plus minerals and vitamins were provided afterwards until 24 d. Diets had 0.1 g/kg phytase and 10 g/kg Celite (indigestible marker). Birds were randomly distributed in a 2 × 2 factorial arrangement of the two SBM with or without protease supplementations (0 or 15,000 protease units/kg) from 17 to 24 d. Excreta were collected from 21 to 23 d and ileal content was collected from all birds. Samples of feed, excreta, and ileal content were analysed for determination of total tract retention and ileal apparent digestibility. No interactions between SBM and protease were observed. Broilers fed semi-purified diets formulated with South SBM had lower (P < 0.05) ileal digestibility of crude protein and also from most amino acids (AA) when compared with birds fed North SBM. Ileal digestible energy was increased (P < 0.01) by 0.51 MJ/kg when birds were fed the diet supplemented with protease. Indispensable and dispensable AA digestibility also increased (P < 0.05) with protease supplementation. Ileal digestibility coefficients of Met, Lys, Thr and Val were increased (P < 0.05) by 3.1%, 3.1%, 4.8%, and 3.3%, respectively when birds were fed the diet supplemented with protease. Results from this experiment show that utilisation of energy and AA from SBM depends on its origin, but protease supplementation improved their utilisation regardless of the SBM source.

Research paper thumbnail of Performance and Carcass Composition of Broilers Fed Different Carbohydrate and Protein Sources in the Prestarter Phase

Journal of Applied Poultry Research, 2007

Chicken growth rate has increased substantially in the past decades, causing slaughter weight to ... more Chicken growth rate has increased substantially in the past decades, causing slaughter weight to be attained sooner and increasing the representativeness of the first days of life. Prestarter diets are presently used in a variety of situations in poultry production and are interpreted as investment, not a cost in production. Studies to define the nutrient requirements in the prestarter period are seconded by the necessity to search for ingredients with high nutrient availability that will result in improved animal performance associated with good carcass quality. Alternative ingredients with excellent digestibility must be used in diets for newly hatched chicks, because their digestive system is not completely adapted to the digestion and absorption of feeds. This research evaluated the effects of alternative carbohydrate and protein sources in prestarter broiler chicken diets on the performance, digestive organ morphometry, and carcass composition and yield. The effects of different carbohydrate and protein sources found at the prestarter phase were not maintained in subsequent phases.

Research paper thumbnail of Dietary protein and amino acids-consideration of the undigestible fraction

Poultry science, 2014

A case is made for the application of true ileal amino acid digestibility and true ileal reactive... more A case is made for the application of true ileal amino acid digestibility and true ileal reactive lysine digestibility (lysine availability) in poultry nutrition. Technical aspects of the true ileal digestibility assays are reviewed, as are factors influencing amino acid digestibility in the broiler. There is considerable variation in amino acid digestibility and lysine availability both within and among diverse feedstuffs. Differences in mean amino acid digestibility among feedstuffs, and the variability in the digestibility of an amino acid within a feedstuff should both be taken into account during least-cost dietary formulation.

Research paper thumbnail of Why is it important to understand substrates if we are to optimize exogenous enzyme efficacy?

Poultry science, 2014

The use of exogenous enzymes in feeds for poultry has increased dramatically between 1990 and 201... more The use of exogenous enzymes in feeds for poultry has increased dramatically between 1990 and 2013. Today, the use of enzymes is broad, going beyond phytases and β-glucanases and xylanases to include other carbohydrases and proteases as well as lipases. The number of scientific articles and publications related to enzymes in feed clearly shows that this has been an area of intense and broad interest for scientists and nutritionists. However, knowledge of the different substrates available in the feed and how these substrates change depending on feed ingredient selection has not received the same level of attention. Understanding substrates is key to better developing and implementing exogenous enzymes. Of importance today is to potentiate endogenous digestive capabilities and use exogenous enzymes to optimize nutrient digestion and use. Our aim with this symposium was to call attention to the importance of having a more in-depth knowledge about substrates and to fill the large gaps ...

Research paper thumbnail of Carboidratos na dieta pré-inicial de frangos de corte

Revista Brasileira de Zootecnia, 2005

Objetivou-se, com este estudo, determinar a energia metabolizável aparente corrigida (EMAn) de in... more Objetivou-se, com este estudo, determinar a energia metabolizável aparente corrigida (EMAn) de ingredientes como fonte de carboidrato para frangos de corte de 1 a 7 dias de idade, bem como avaliar a utilização destes diferentes ingredientes em dietas pré-iniciais sobre o desenvolvimento inicial de órgãos do trato gastrintestinal (TGI) e desempenho das aves. No Experimento 1, foi utilizado o método de coleta total das excretas com 220 pintos de 4 a 7 dias de idade, alojados em baterias em delineamento inteiramente casualizado com cinco tratamentos (uma dieta-referência e quatro dietas com inclusão de 20% do ingrediente-teste - amido de milho [AMI], amido de mandioca [AMA], glicose [GLI] e sacarose [SAC]) e quatro repetições de 11 aves. No Experimento 2, foram utilizados 520 pintos de corte machos de um dia de idade, distribuídos em delineamento inteiramente casualizado, com cinco tratamentos e quatro repetições de 26 aves. Os tratamentos foram aplicados de 1 a 7 dias e, no período su...

Research paper thumbnail of Diferentes fontes de proteína na dieta pré-inicial de frangos de corte

Revista Brasileira de Zootecnia, 2005

Objetivou-se, com este estudo, determinar o valor de energia metabolizável aparente corrigida (EM... more Objetivou-se, com este estudo, determinar o valor de energia metabolizável aparente corrigida (EMAn) de ingredientes protéicos alternativos, para frangos de corte na fase pré-inicial, e avaliar os efeitos da utilização desses ingredientes na primeira semana de vida de frangos sobre o desempenho e o desenvolvimento do trato gastrintestinal (TGI). No ensaio de metabolismo, 288 aves (4 a 7 dias de idade) foram distribuídas em seis tratamentos (uma dieta-referência e cinco dietas com inclusão dos ingredientes-teste: isolado protéico de soja [IS], ovo em pó [OP], plasma sangüíneo [PS], farelo de glúten de milho [GM] e levedura seca [LS]) e quatro repetições de 12 aves. Na avaliação do desempenho e do TGI, 624 aves foram alojadas em baterias com seis tratamentos e quatro repetições de 26 aves. Os tratamentos consistiram em: 1 - dieta de milho e farelo de soja, 2 - dieta de milho e farelo de soja + IS, 3 - dieta de milho e farelo de soja + OP, 4 - dieta de milho e farelo de soja + PS, 5 - ...

Research paper thumbnail of Oxidação lipídica do óleo de vísceras de aves para redução de seu conteúdo de energia metabolizável para frangos de corte na fase de crescimento

Revista Brasileira de Zootecnia, 2004

Com a finalidade de determinar os teores de energia metabolizável aparente (EMA) e de energia met... more Com a finalidade de determinar os teores de energia metabolizável aparente (EMA) e de energia metabolizável aparente corrigida para o nitrogênio (EMAn) do óleo de vísceras de aves fresco e oxidado, foi conduzido um ensaio metabólico utilizando-se 48 machos AgRoss com 31 dias de idade. As aves foram alojadas em gaiolas metabólicas e o método utilizado foi o de coleta total de excretas. Foi fornecida uma dieta-referência com ou sem substituição de 10% pelo óleo de vísceras de aves fresco ou oxidado, sendo que cada dieta foi oferecida a quatro repetições de quatro aves. O período de coleta foi de quatro dias após três dias de adaptação às dietas e às gaiolas. O óleo de vísceras de aves foi adquirido de um produtor local e armazenado sob congelamento a -18ºC (óleo fresco). O óleo oxidado foi obtido por aquecimento em banho-maria com temperatura entre 80 e 90ºC. Durante o período de aquecimento, a qualidade deste óleo foi controlada por avaliações periódicas da absorbância específica, qu...

Research paper thumbnail of Effects of canthaxanthin on the productive and reproductive performance of broiler breeders

Poultry Science, 2012

The effects of supplementing canthaxanthin on productive and reproductive aspects of broiler bree... more The effects of supplementing canthaxanthin on productive and reproductive aspects of broiler breeders were examined in this study. In total, 360 female pullets and 36 roosters were placed in an open-sided house with 12 pens, each pen with an area of 7.0 m(2) (3.5 × 2.0 m). At 42 wk of age, the breeder hens and roosters were distributed into 2 experimental groups with similar BW and uniformity. From 46 to 66 wk of age, one group received 6 mg/kg of canthaxanthin supplemented in the diet and the other group received the diet without the addition of canthaxanthin (control diet). Body weight was measured every 28 d, the laying rate was calculated weekly, and mortality was evaluated at the end of the study. Twenty-one weekly incubations were performed to evaluate fertility and incubation responses. To evaluate the antioxidant effect of canthaxanthin at different storage times and during the incubation process, eggs from each treatment were subject to thiobarbituric reactive substances analysis. Body weight, mortality, and laying rate were not affected by the inclusion of canthaxanthin in the breeder&amp;amp;amp;amp;amp;amp;#39;s diets. An increase in hatchability of total and fertile eggs (P ≤ 0.0001 and P ≤ 0.0003, respectively) in breeders fed canthaxanthin during the experimental period was observed. Canthaxanthin also improved breeder fertility and reduced embryo mortality. This can be attributed to reductions in embryo mortality in the first 48 h of incubation and in the last wk of incubation. No differences were observed in BW and quality of the chicks. A reduction of thiobarbituric reactive substances was observed in yolks from stored hatching eggs produced by breeders fed diets plus canthaxanthin. The same effect was observed in yolks of eggs stored for 4 d and incubated for 7 d. The supplementation of broiler breeder diets with canthaxanthin improved the hatchability rate, fertility, and reduced the presence of thiobarbituric reactive substances in eggs.

Research paper thumbnail of Intestinal Bacterial Community and Growth Performance of Chickens Fed Diets Containing Antibiotics

Poultry Science, 2006

This study was conducted to relate the performance of broiler chickens fed diets containing growt... more This study was conducted to relate the performance of broiler chickens fed diets containing growth-promoting antibiotics to changes in the intestinal microbiota. The technique of denaturing gradient gel electrophoresis (DGGE) of amplicons of the region V3 of 16S rDNA was used to characterize the microbiota. Two experiments were conducted, one with broilers raised in battery cages and the other with broilers raised in floor pens. Antibiotics improved the performance of the chickens raised in floor pens only. Avilamycin, bacitracin methylene disalicylate, and enramycin induced changes in the composition of the intestinal bacterial community of the birds in both experiments. The number of bacterial genotypes found in the intestinal tract of chickens was not reduced by the antibiotics supplemented in either environment. However, the changes in the composition of the intestinal bacterial community induced by antibiotics may be related to improvement in growth performance. This was indicated by the suppression of 6 amplicons and the presence of 4 amplicons exclusive to the treatment that had the best performance in the floor pen experiment.

Research paper thumbnail of Enzymatic programs for broilers

Brazilian Archives of Biology and Technology, 2009

Two trials were conducted on floor pens to evaluate the performance of broilers fed with diets co... more Two trials were conducted on floor pens to evaluate the performance of broilers fed with diets contained different carbohydrases enzyme programs at different ages. Trial 1- The body weight gain (BWG) was affected by the Negative Control (NC) treatment (P<0.05). However, when the birds were fed with the NC diet + Amilase (AMY)+Xilanase (XYL), the BWG improved and reached the same level as the Positive Control (PC). Trial 2- The birds received enzymes supplementation in the total phase and others only in the grower phase.The ME reduction by 120 kcal/kg increased the feed conversion ratio (FCR) (P<0.05) when compared to PC and none of the enzyme programs was able to recover the performance. It can be concluded that it is possible to supplement with AMY during the role period of broiler chicken life or use an enzymatic program with AMY or AMY+XYL only in the grower phase.

Research paper thumbnail of Allometric growth of the gastrointestinal tract of broilers from 1 to 7 day-old

The study of broiler chicken pre-starter nutrition is an important tool to maximize the expressio... more The study of broiler chicken pre-starter nutrition is an important tool to maximize the expression of growth potential. The objective of this trial was to analyze the allometric growth of the gastrointestinal tract of chicks fed different carbohydrates sources from 1 to 7 days of age. Birds were distributed in a completely randomized experimental design in brooder batteries with six treatments (feed with 20% ME requirement from glucose, sucrose, corn starch, cassava starch or 5% from lactose) and four replicates of 26 chicks each. Two chicks per experimental unit were daily euthanized to analyze the allometric growth of the gastrointestinal organs from days 1-7. The following generated equations describe intestinal tract development: Yolk sac (%BW) = 7.7753-2,8574x+0.2564x² (R²=0.84); Proventriculus (%BW) =0.9859+0.2018x-0.0264x² (R²=0.28); Gizzard (%BW) = 5.7252+0.0387x-0.0349x² (R²=0.73); Small Intestine weight (%BW) = 2.3806+1.0076x-0.0887x² (R²=0.63); Small Intestine length (cm) = 40.1310+13.2326x-0.6647x² (R²=0.92); Weight/Length ratio (g/cm) = 0.0234+0.0097x (r²=0.83); Pancreas (%BW) = 0.1536+0.1433x-0.0138x² (R²=0.61); Liver (%BW) = 2.7400+1.1235x-0.1264x² (R²=0.52); where x is bird age. Yolk sac, pancreas and proventriculus were not affected by the treatments, while different carbohydrate sources influenced gizzard, liver and small intestine weight (%BW) and small intestine length (cm) and density (g/cm). Contrast analyses of the gizzard showed higher %BW in control vs. treated birds, sucrose vs. glucose, and lactose vs. sugars and starch. Liver was affected by the treatments, particularly by glucose (5.3%BW) as compared to birds fed lactose, which had the lowest %BW (4.7%BW). Small intestine weight was significantly affected by lactose treatment (4.6%BW-highest value) and glucose (4.1%BW-lowest value). Small intestine length was only affected by the lactose treatment, presenting a longer small intestine.(79.7 vs. 76.7 cm). Contrast analyses of small intestine weight/length ratio were significant only for the glucose vs. sucrose contrast (0.0617g/cm vs. 0.0659g/cm, respectively).

Research paper thumbnail of Effects of different carbohydrates in the feed of newly hatched chicks on performance and organs allometric growth

Research paper thumbnail of Probióticos não alteram os índices zootécnicos e a estrutura da comunidade microbiana intestinal de frangos de corte

Research paper thumbnail of Effects of different protein sources in the feed of newly hatched on broiler performance

Research paper thumbnail of Oxidative stability of thigh meat from broilers fed oxidized poultry offal fat

Research paper thumbnail of Efeito do peso de pintos de corte ao alojamento sobre o desempenho de frangos até 42 dias

Research paper thumbnail of Energy and nutrient utilisation of broilers fed soybean meal from two different Brazilian production areas with an exogenous protease

Animal Feed Science and Technology, 2016

A study was conducted to evaluate the effects of an exogenous protease added to diets having soyb... more A study was conducted to evaluate the effects of an exogenous protease added to diets having soybean meal (SBM) from two geographic areas in Brazil (South or North). Evaluation was conducted on energy utilisation and nutrient digestibility using 224 slow feathering Cobb × Cobb 500 male broilers. Birds were fed a common starter diet to d 15. Semi-purified experimental diets containing 555 g/kg SBM and 408 g/kg maize starch plus minerals and vitamins were provided afterwards until 24 d. Diets had 0.1 g/kg phytase and 10 g/kg Celite (indigestible marker). Birds were randomly distributed in a 2 × 2 factorial arrangement of the two SBM with or without protease supplementations (0 or 15,000 protease units/kg) from 17 to 24 d. Excreta were collected from 21 to 23 d and ileal content was collected from all birds. Samples of feed, excreta, and ileal content were analysed for determination of total tract retention and ileal apparent digestibility. No interactions between SBM and protease were observed. Broilers fed semi-purified diets formulated with South SBM had lower (P < 0.05) ileal digestibility of crude protein and also from most amino acids (AA) when compared with birds fed North SBM. Ileal digestible energy was increased (P < 0.01) by 0.51 MJ/kg when birds were fed the diet supplemented with protease. Indispensable and dispensable AA digestibility also increased (P < 0.05) with protease supplementation. Ileal digestibility coefficients of Met, Lys, Thr and Val were increased (P < 0.05) by 3.1%, 3.1%, 4.8%, and 3.3%, respectively when birds were fed the diet supplemented with protease. Results from this experiment show that utilisation of energy and AA from SBM depends on its origin, but protease supplementation improved their utilisation regardless of the SBM source.

Research paper thumbnail of Performance and Carcass Composition of Broilers Fed Different Carbohydrate and Protein Sources in the Prestarter Phase

Journal of Applied Poultry Research, 2007

Chicken growth rate has increased substantially in the past decades, causing slaughter weight to ... more Chicken growth rate has increased substantially in the past decades, causing slaughter weight to be attained sooner and increasing the representativeness of the first days of life. Prestarter diets are presently used in a variety of situations in poultry production and are interpreted as investment, not a cost in production. Studies to define the nutrient requirements in the prestarter period are seconded by the necessity to search for ingredients with high nutrient availability that will result in improved animal performance associated with good carcass quality. Alternative ingredients with excellent digestibility must be used in diets for newly hatched chicks, because their digestive system is not completely adapted to the digestion and absorption of feeds. This research evaluated the effects of alternative carbohydrate and protein sources in prestarter broiler chicken diets on the performance, digestive organ morphometry, and carcass composition and yield. The effects of different carbohydrate and protein sources found at the prestarter phase were not maintained in subsequent phases.

Research paper thumbnail of Dietary protein and amino acids-consideration of the undigestible fraction

Poultry science, 2014

A case is made for the application of true ileal amino acid digestibility and true ileal reactive... more A case is made for the application of true ileal amino acid digestibility and true ileal reactive lysine digestibility (lysine availability) in poultry nutrition. Technical aspects of the true ileal digestibility assays are reviewed, as are factors influencing amino acid digestibility in the broiler. There is considerable variation in amino acid digestibility and lysine availability both within and among diverse feedstuffs. Differences in mean amino acid digestibility among feedstuffs, and the variability in the digestibility of an amino acid within a feedstuff should both be taken into account during least-cost dietary formulation.

Research paper thumbnail of Why is it important to understand substrates if we are to optimize exogenous enzyme efficacy?

Poultry science, 2014

The use of exogenous enzymes in feeds for poultry has increased dramatically between 1990 and 201... more The use of exogenous enzymes in feeds for poultry has increased dramatically between 1990 and 2013. Today, the use of enzymes is broad, going beyond phytases and β-glucanases and xylanases to include other carbohydrases and proteases as well as lipases. The number of scientific articles and publications related to enzymes in feed clearly shows that this has been an area of intense and broad interest for scientists and nutritionists. However, knowledge of the different substrates available in the feed and how these substrates change depending on feed ingredient selection has not received the same level of attention. Understanding substrates is key to better developing and implementing exogenous enzymes. Of importance today is to potentiate endogenous digestive capabilities and use exogenous enzymes to optimize nutrient digestion and use. Our aim with this symposium was to call attention to the importance of having a more in-depth knowledge about substrates and to fill the large gaps ...

Research paper thumbnail of Carboidratos na dieta pré-inicial de frangos de corte

Revista Brasileira de Zootecnia, 2005

Objetivou-se, com este estudo, determinar a energia metabolizável aparente corrigida (EMAn) de in... more Objetivou-se, com este estudo, determinar a energia metabolizável aparente corrigida (EMAn) de ingredientes como fonte de carboidrato para frangos de corte de 1 a 7 dias de idade, bem como avaliar a utilização destes diferentes ingredientes em dietas pré-iniciais sobre o desenvolvimento inicial de órgãos do trato gastrintestinal (TGI) e desempenho das aves. No Experimento 1, foi utilizado o método de coleta total das excretas com 220 pintos de 4 a 7 dias de idade, alojados em baterias em delineamento inteiramente casualizado com cinco tratamentos (uma dieta-referência e quatro dietas com inclusão de 20% do ingrediente-teste - amido de milho [AMI], amido de mandioca [AMA], glicose [GLI] e sacarose [SAC]) e quatro repetições de 11 aves. No Experimento 2, foram utilizados 520 pintos de corte machos de um dia de idade, distribuídos em delineamento inteiramente casualizado, com cinco tratamentos e quatro repetições de 26 aves. Os tratamentos foram aplicados de 1 a 7 dias e, no período su...

Research paper thumbnail of Diferentes fontes de proteína na dieta pré-inicial de frangos de corte

Revista Brasileira de Zootecnia, 2005

Objetivou-se, com este estudo, determinar o valor de energia metabolizável aparente corrigida (EM... more Objetivou-se, com este estudo, determinar o valor de energia metabolizável aparente corrigida (EMAn) de ingredientes protéicos alternativos, para frangos de corte na fase pré-inicial, e avaliar os efeitos da utilização desses ingredientes na primeira semana de vida de frangos sobre o desempenho e o desenvolvimento do trato gastrintestinal (TGI). No ensaio de metabolismo, 288 aves (4 a 7 dias de idade) foram distribuídas em seis tratamentos (uma dieta-referência e cinco dietas com inclusão dos ingredientes-teste: isolado protéico de soja [IS], ovo em pó [OP], plasma sangüíneo [PS], farelo de glúten de milho [GM] e levedura seca [LS]) e quatro repetições de 12 aves. Na avaliação do desempenho e do TGI, 624 aves foram alojadas em baterias com seis tratamentos e quatro repetições de 26 aves. Os tratamentos consistiram em: 1 - dieta de milho e farelo de soja, 2 - dieta de milho e farelo de soja + IS, 3 - dieta de milho e farelo de soja + OP, 4 - dieta de milho e farelo de soja + PS, 5 - ...

Research paper thumbnail of Oxidação lipídica do óleo de vísceras de aves para redução de seu conteúdo de energia metabolizável para frangos de corte na fase de crescimento

Revista Brasileira de Zootecnia, 2004

Com a finalidade de determinar os teores de energia metabolizável aparente (EMA) e de energia met... more Com a finalidade de determinar os teores de energia metabolizável aparente (EMA) e de energia metabolizável aparente corrigida para o nitrogênio (EMAn) do óleo de vísceras de aves fresco e oxidado, foi conduzido um ensaio metabólico utilizando-se 48 machos AgRoss com 31 dias de idade. As aves foram alojadas em gaiolas metabólicas e o método utilizado foi o de coleta total de excretas. Foi fornecida uma dieta-referência com ou sem substituição de 10% pelo óleo de vísceras de aves fresco ou oxidado, sendo que cada dieta foi oferecida a quatro repetições de quatro aves. O período de coleta foi de quatro dias após três dias de adaptação às dietas e às gaiolas. O óleo de vísceras de aves foi adquirido de um produtor local e armazenado sob congelamento a -18ºC (óleo fresco). O óleo oxidado foi obtido por aquecimento em banho-maria com temperatura entre 80 e 90ºC. Durante o período de aquecimento, a qualidade deste óleo foi controlada por avaliações periódicas da absorbância específica, qu...

Research paper thumbnail of Effects of canthaxanthin on the productive and reproductive performance of broiler breeders

Poultry Science, 2012

The effects of supplementing canthaxanthin on productive and reproductive aspects of broiler bree... more The effects of supplementing canthaxanthin on productive and reproductive aspects of broiler breeders were examined in this study. In total, 360 female pullets and 36 roosters were placed in an open-sided house with 12 pens, each pen with an area of 7.0 m(2) (3.5 × 2.0 m). At 42 wk of age, the breeder hens and roosters were distributed into 2 experimental groups with similar BW and uniformity. From 46 to 66 wk of age, one group received 6 mg/kg of canthaxanthin supplemented in the diet and the other group received the diet without the addition of canthaxanthin (control diet). Body weight was measured every 28 d, the laying rate was calculated weekly, and mortality was evaluated at the end of the study. Twenty-one weekly incubations were performed to evaluate fertility and incubation responses. To evaluate the antioxidant effect of canthaxanthin at different storage times and during the incubation process, eggs from each treatment were subject to thiobarbituric reactive substances analysis. Body weight, mortality, and laying rate were not affected by the inclusion of canthaxanthin in the breeder&amp;amp;amp;amp;amp;amp;#39;s diets. An increase in hatchability of total and fertile eggs (P ≤ 0.0001 and P ≤ 0.0003, respectively) in breeders fed canthaxanthin during the experimental period was observed. Canthaxanthin also improved breeder fertility and reduced embryo mortality. This can be attributed to reductions in embryo mortality in the first 48 h of incubation and in the last wk of incubation. No differences were observed in BW and quality of the chicks. A reduction of thiobarbituric reactive substances was observed in yolks from stored hatching eggs produced by breeders fed diets plus canthaxanthin. The same effect was observed in yolks of eggs stored for 4 d and incubated for 7 d. The supplementation of broiler breeder diets with canthaxanthin improved the hatchability rate, fertility, and reduced the presence of thiobarbituric reactive substances in eggs.

Research paper thumbnail of Intestinal Bacterial Community and Growth Performance of Chickens Fed Diets Containing Antibiotics

Poultry Science, 2006

This study was conducted to relate the performance of broiler chickens fed diets containing growt... more This study was conducted to relate the performance of broiler chickens fed diets containing growth-promoting antibiotics to changes in the intestinal microbiota. The technique of denaturing gradient gel electrophoresis (DGGE) of amplicons of the region V3 of 16S rDNA was used to characterize the microbiota. Two experiments were conducted, one with broilers raised in battery cages and the other with broilers raised in floor pens. Antibiotics improved the performance of the chickens raised in floor pens only. Avilamycin, bacitracin methylene disalicylate, and enramycin induced changes in the composition of the intestinal bacterial community of the birds in both experiments. The number of bacterial genotypes found in the intestinal tract of chickens was not reduced by the antibiotics supplemented in either environment. However, the changes in the composition of the intestinal bacterial community induced by antibiotics may be related to improvement in growth performance. This was indicated by the suppression of 6 amplicons and the presence of 4 amplicons exclusive to the treatment that had the best performance in the floor pen experiment.

Research paper thumbnail of Enzymatic programs for broilers

Brazilian Archives of Biology and Technology, 2009

Two trials were conducted on floor pens to evaluate the performance of broilers fed with diets co... more Two trials were conducted on floor pens to evaluate the performance of broilers fed with diets contained different carbohydrases enzyme programs at different ages. Trial 1- The body weight gain (BWG) was affected by the Negative Control (NC) treatment (P<0.05). However, when the birds were fed with the NC diet + Amilase (AMY)+Xilanase (XYL), the BWG improved and reached the same level as the Positive Control (PC). Trial 2- The birds received enzymes supplementation in the total phase and others only in the grower phase.The ME reduction by 120 kcal/kg increased the feed conversion ratio (FCR) (P<0.05) when compared to PC and none of the enzyme programs was able to recover the performance. It can be concluded that it is possible to supplement with AMY during the role period of broiler chicken life or use an enzymatic program with AMY or AMY+XYL only in the grower phase.

Research paper thumbnail of Allometric growth of the gastrointestinal tract of broilers from 1 to 7 day-old

The study of broiler chicken pre-starter nutrition is an important tool to maximize the expressio... more The study of broiler chicken pre-starter nutrition is an important tool to maximize the expression of growth potential. The objective of this trial was to analyze the allometric growth of the gastrointestinal tract of chicks fed different carbohydrates sources from 1 to 7 days of age. Birds were distributed in a completely randomized experimental design in brooder batteries with six treatments (feed with 20% ME requirement from glucose, sucrose, corn starch, cassava starch or 5% from lactose) and four replicates of 26 chicks each. Two chicks per experimental unit were daily euthanized to analyze the allometric growth of the gastrointestinal organs from days 1-7. The following generated equations describe intestinal tract development: Yolk sac (%BW) = 7.7753-2,8574x+0.2564x² (R²=0.84); Proventriculus (%BW) =0.9859+0.2018x-0.0264x² (R²=0.28); Gizzard (%BW) = 5.7252+0.0387x-0.0349x² (R²=0.73); Small Intestine weight (%BW) = 2.3806+1.0076x-0.0887x² (R²=0.63); Small Intestine length (cm) = 40.1310+13.2326x-0.6647x² (R²=0.92); Weight/Length ratio (g/cm) = 0.0234+0.0097x (r²=0.83); Pancreas (%BW) = 0.1536+0.1433x-0.0138x² (R²=0.61); Liver (%BW) = 2.7400+1.1235x-0.1264x² (R²=0.52); where x is bird age. Yolk sac, pancreas and proventriculus were not affected by the treatments, while different carbohydrate sources influenced gizzard, liver and small intestine weight (%BW) and small intestine length (cm) and density (g/cm). Contrast analyses of the gizzard showed higher %BW in control vs. treated birds, sucrose vs. glucose, and lactose vs. sugars and starch. Liver was affected by the treatments, particularly by glucose (5.3%BW) as compared to birds fed lactose, which had the lowest %BW (4.7%BW). Small intestine weight was significantly affected by lactose treatment (4.6%BW-highest value) and glucose (4.1%BW-lowest value). Small intestine length was only affected by the lactose treatment, presenting a longer small intestine.(79.7 vs. 76.7 cm). Contrast analyses of small intestine weight/length ratio were significant only for the glucose vs. sucrose contrast (0.0617g/cm vs. 0.0659g/cm, respectively).