Efficacy of the phytogenic feed additive oregano essential oil (OEO) (Origanum vulgare L.) was assessed as an alternative to an antibiotic as a growth promoter (AGP) in broiler diets. Three hundred male broiler chicks were assigned to five treatments, which consisted of diets with different levels of OEO (300, 600, and 900 mg/kg of diet), a negative control, and a positive control. Broiler performance was evaluated from 1 to 21 and 1 to 39 days old. From 1 to 39 days old, the broilers of the negative control group presented lower feed intake than those fed OEO300. No significant effect was observed on weight gain. The greatest feed conversion ratio occurred in the positive control group. Broilers treated with OEO300 had greater carcass yield than those in the positive control group. The haemogram, leukogram, and heterophil/lymphocyte ratio were positively influenced by OEO300. Red blood cell and leukocyte counts increased in a dose-dependent manner in broilers fed OEO-supplemented diets, while broilers in the positive control group had the lowest levels of haematocrit, mean corpuscular haemoglobin concentration, and plasma protein. Differential leukometry revealed lymphocyte numbers were increased with OEO treatment and reduced in the positive control group. For hepatic and renal metabolism, the broilers in the positive control group exhibited the greatest serum activities of aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, and alkaline phosphatase. Although more studies on its efficacy are needed, OEO at 300 mg/kg may be used as a phytogenic additive in broiler diets, especially those without AGP.

Five experiments were conducted to estimate the digestible threonine requirements of slow-growing broilers: experiment 1, starter phase (days 10 to 28); experiment 2, grower I phase (days 29 to 49); experiment 3, grower II phase (days 50 to 69); experiment 4, finisher phase (days 70 to 84); and experiment 5, which was specifically conducted to determine the production of intestinal mucin over two periods (days 50 to 69 and 70 to 84). Different birds were used in all experiments. A completely randomized design with five treatments and four replicates was used. Treatments consisted of increasing the values of digestible threonine in the diet through basal feed supplementation with L-threonine (98.5%), which was added instead of cornstarch. The following values of digestible threonine were investigated: 0.622, 0.697, 0.772, 0.847, and 0.922% in experiment 1; 0.586, 0.662, 0.738, 0.814, and 0.890% in experiment 2; 0.570, 0.640, 0.71, 0.780, and 0.850% in experiments 3 and 5; and 0.520, 0.595, 0.670, 0.745, and 0.820% in experiments 4 and 5. The digestible threonine values presented quadratic effects on feed conversion ratio in experiments 1, 2, and 3. Digestible threonine values of 0.628 and 0.609% resulted in higher villus height and greater duodenal crypt depth, respectively. Digestible threonine values of 0.762, 0.767, and 0.733% may be recommended for the starter, grower I, and grower II phases, respectively, based on the best feed conversion ratio. In addition, a digestible threonine level of 0.694% may be recommended for the finisher phase based on the highest production of intestinal mucin.

RESUMO -Um experimento foi realizado para avaliar a influência da forma física da ração sobre o desempenho e as características da carcaça de frangos de corte. Foram utilizados 240 pintos de corte machos, distribuídos e alojados em baterias metálicas de três andares em delineamento de blocos ao acaso com 4 formas físicas de ração e 6 repetições com 10 aves por unidade experimental, considerando cada andar um bloco. Os tratamentos consistiram em rações farelada, peletizada, expandida e expandida peletizada. Os índices de desempenho foram analisados no período de 1 a 22 e 1 a 39 dias de idade das aves. Duas aves com peso médio do grupo foram retiradas de cada repetição e abatidas aos 40 dias de idade para avaliação da carcaça. A forma física da ração afetou o desempenho e as características da carcaça dos frangos. Nos períodos de 1 a 22 dias e de 1 a 39 dias, os frangos que consumiram o alimento farelado apresentaram menor consumo de ração, peso médio e ganho de peso, enquanto aqueles que receberam ração peletizada não apresentaram diferença no peso médio, ganho de peso e conversão alimentar em relação àqueles que receberam ração expandida peletizada. Os maiores resultados para essas variáveis foram observados para aves alimentadas com ração peletizada ou expandida peletizada. As aves que receberam ração expandida peletizada apresentaram melhores resultados de peso de carcaça e dos cortes em relação àquelas que receberam a ração farelada e este melhor resultado não diferiu do encontrado para as aves alimentadas com ração peletizada. Recomenda-se o uso de rações na forma física peletizada ou expandida peletizada, pois promoveram os melhores índices zootécnicos. Palavras-chave: aves, nutrição, processamento da ração Performance and carcass characteristics of broilers fed diets of different physical formsABSTRACT -An experiment was conducted to evaluate the influence of the physical form of feed on performance and carcass characteristics of broilers. A total of 240 male broiler chicks were assigned and housed in metal cage of three floors in a randomized block design with 4 physical forms of feed and 6 repetitions with 10 birds per experimental unit, where each floor represented a block. Treatments consisted of: mash, pelleted, expanded and expanded pelleted diets. Performance indexes were analyzed in the period from 1 to 22 and 1 to 39 days of birds' life. Two birds with an average weight of the group were taken from each repetition and slaughtered at 40 days of age for carcass evaluation. The physical form of ration affected the performance and carcass characteristics of broilers. For the period from 1 to 22 days and from 1 to 39 days, chickens that consumed the mashed food had lower feed intake, weight and weight gain, whereas birds fed pelleted diets showed no difference in weight, weight gain or feed conversion from those fed expanded pelleted diets. The major results for these variables were observed for birds fed pelleted or expanded pelleted diets. Birds fed expanded pelleted diets showed the best results for...

Background: Kaolin may improve quail performance by maintaining intestinal integrity and improving nutrient absorption. Objective: To evaluate the overall performance, egg quality, moisture, nitrogen and calcium content in the excreta, intestinal morphology and financial analysis of kaolin in Japanese quail feed during the production phase. Methods: A total of 192 Japanese quails, distributed in a completely randomized design with four treatments and six repetitions with eight birds each, were used. Kaolin levels added to the diet were 0, 1.5, 3.0, and 4.5%. Results: Kaolin reduced feed consumption. Additionally, egg production, feed conversion and viability increased. Moisture, nitrogen and calcium in the excreta decreased. Height and width of the intestinal villi increased with increasing levels of kaolin in the diet. Kaolin had no effect on egg quality. Inclusion level of 1.5% kaolin allowed for greater economic gains. Conclusion: Kaolin improved performance, intestinal morphology, and reduced the moisture, nitrogen and calcium contents in the excreta. Egg quality remained unchanged with the addition of kaolin, and the best economic response resulted with the addition 1.5% kaolin.

O caulim adsorve toxinas e patógenos no trato gastrointestinal permitindo maior digestão e absorção de nutrientes, podendo propiciar melhor qualidade óssea de poedeiras na fase final de produção, mas adsorção de minerais, redução da digestibilidade da ração, também podem ser observados, dependendo do nível de inclusão da argila. Portanto o objetivo deste estudo é verificar a inclusão de caulim na ração de galinhas poedeiras semipesadas no final do ciclo produtivo e sua influência sobre a digestibilidade aparente da matéria seca, retenção e excreção mineral e qualidade óssea. Foram alojadas 144 galinhas em delineamento inteiramente casualizado, em seis tratamentos: controle (sem a inclusão do aditivo); e inclusão de 1, 2, 3, 4 e 5% de caulim na dieta. Às 85 semanas de idade das aves foram mensuradas a digestibilidade aparente da matéria seca da ração (Digap), a excreção e retenção de matéria mineral, e a excreção de cálcio e fósforo, para qualidade óssea foram mensurados o índice Seedor e a matéria mineral e resistência a quebra da tíbia. Após análise de variância, os dados foram submetidos à analise de regressão ao nível de significância de 5%. A Digap e a excreção de matéria mineral pioraram (P<0,05) com a elevação da concentração de caulim na ração, já a retenção de matéria mineral se comportou de maneira quadrática, não houve diferença significativa (P>0,05) na excreção de cálcio e fósforo. O índice de seedor aumentou de maneira linear (P<0,05), não havendo diferença significativa para os demais parâmetros ósseos (P>0,05). A inclusão de caulim favoreceu a retenção de minerais e a qualidade óssea em galinhas poedeiras no final do ciclo produtivo, não promovendo alteração na retenção do cálcio e do fósforo e reduziu a digestibilidade da ração.

RESUMO Objetivou-se avaliar o uso de rações, contendo prebiótico ou antibiótico, nas fases pré e pós-alojamento sobre o desempenho de frangos de corte. Foram utilizados 720 pintos de um dia, machos, da linhagem Cobb-3500, distribuídos em blocos casualizados com quatro tratamentos, com seis repetições de 30 aves cada. Os tratamentos consistiram em: Antibiótico - aves que consumiram ração com adição de antibiótico nas fases pré e pós-alojamento; Prebiótico - aves que consumiram ração com adição de prebiótico nas fases pré e pós-alojamento; Sem aditivo- aves que consumiram ração sem aditivo nas fases pré e pós-alojamento; Jejum - aves que permaneceram em jejum na fase pré-alojamento e consumo de ração com antibiótico nas fases pós-alojamento. O fornecimento de ração pré-alojamento, dentro das caixas de transporte se iniciou no incubatório, sendo o tempo pré-alojamento de 24 horas. Para avalição do desempenho produtivo das aves, aferiram-se as variáveis de: peso médio, consumo de ração, ganho de peso, conversão alimentar, fator de produção e viabilidade criatória. A utilização de ração préalojamento com prebiótico ou antibiótico promoveu melhorias significativas (P<0,05) no peso vivo e no ganho de peso dos pintos na fase de 1 a 7 dias. Tal fato ocorreu, independente do uso de aditivos nas rações fornecidas no préalojamento e na fase pré-inicial. O desempenho final dos frangos de corte não foi influenciado (P>0,05) pela utilização de aditivo nas fases de pré e pós-alojamento. Assim, conclui-se que o fornecimento de ração pré-alojamento não é necessária para frangos de corte, no período de jejum testado.

The objective of the present study was to evaluate the effects of xylanase and probiotic supplementation on the performance, carcass characteristics, intestinal pH, intestinal viscosity, and ileal microbiota of broiler chickens fed diets containing wheat bran. The study animals were kept in metal cages, and the study was performed using a completely randomized design, with four treatments, six birds per treatment, and six replicates. The four treatments included a control group, a probiotic-supplemented group, a xylanase-supplemented group, and a group that received both xylanase and probiotic supplementation. The diets of all four groups contained wheat bran (50 and 30 g/kg for the starter and grower phases, respectively) and phytase, and at 10 d after hatching, the experimental birds were challenged orally with Eimeria sp commercial vaccine. During the initial phase, supplementation with xylanase, probiotics, or their combination yielded greater weight gains than the control diet; however, considering the period from 10-35 d, the chickens receiving xylanase + probiotic and the diet without the additives showed lower weight gain (2.746 and 2.600 kg, respectively). All the supplemented diets reduced cecum viscosity, and supplementation with probiotic showed a significantly lower pH (6.11). The ileal microbiota was also influenced by xylanase and probiotic supplementation, modulating the frequencies of the genera Lactobacillus and Clostridium. The positive effects of supplementation with xylanase or probiotics alone were similar to those of co-supplementation, and no associative effect was observed.

The intestinal health makes it possible to maintain the efficient and sustainable physiology of the gastrointestinal tract of birds. The gastrointestinal tract has digestive, absorptive, metabolic, immunological and endocrine functions. Thus, impaired intestinal health can systematically affect various functions of the body. The objective of this review is to characterize the importance of intestinal health in broilers. The methodology adopted was the bibliographic study, and the information obtained from documentary sources. Gastrointestinal functionality was found to be the stable state in which the microbiome and intestinal tract exist in symbiotic balance, with animal welfare and performance not restricted by intestinal dysfunction. Gastrointestinal functionality has gained prominence in poultry because of the growing demands for economic efficiency, welfare, food security, reduction of environmental impacts and restrictions on the use of performance enhancing antimicrobials. Among the essential factors for bird intestinal health are the care of chicks in the first weeks of life, enteric diseases, the quality of feed ingredients and the use of additives that favor the preservation of enterocytes. The intestinal health of broiler chickens is an important characteristic to be maintained and observed in poultry production. A healthy gut is necessary so that the bird can properly perform the physiological processes inherent in its organism and express its productive potential, with diet manipulation being a promising strategy for positively modulating the intestinal microbiota of poultry. The use of agents that have trophic effects on intestinal mucosa contributes to improve the digestibility of nutrients, growth performance and intestinal health of broilers.