ABSTRACT Apparent calcium (Ca) retention and digestibility coefficients are affected by limestone particle size in the diet of laying hens. This study aimed to determine the apparent retention and digestibility coefficients of Ca in limestone of different particle sizes in laying hens. The study comprised 288 Lohmann Brown laying hens (50 weeks of age; 1,964 ± 98 g) distributed in a completely randomized experimental design with a 3 × 2 factorial arrangement [three Ca concentrations (10, 20, and 30 g kg–1) × two limestone particle sizes (480 and 1,978 µm)] with eight repetitions per treatment and six birds per experimental unit. The experiment included five days for adaptation and five days for total excreta collection. All birds were slaughtered at the end of the ten days to collect the ileal contents. The total or ileal Ca content was plotted against the Ca of diets concentration using linear regression analysis. The regression line slope represented the apparent retention (CaR) and digestibility coefficients of Ca (CaD) in limestone. There was interaction between Ca concentration in the diet and limestone granulometry on CaD (p = 0.001) and CaR (p < 0.001). The CaD and CaR of fine- and coarse-grained limestone increased linearly with increasing Ca concentrations in the diet. The apparent digestibility coefficients estimated for laying hens fed with fine-grained and coarse-grained limestone were 0.72 and 0.35, respectively. The apparent retention coefficients estimated for laying hens fed fine-grained and coarse-grained limestone were 0.96 and 0.47, respectively.

ABSTRACT The objective of this study was to evaluate the effects of different levels of microencapsulated carvacrol and cinnamaldehyde on metabolizable energy, feed digestibility, intestinal morphometric analysis, and antioxidant parameters in broilers. A completely randomized design with five treatments and eight replications of eight broilers (Cobb male) was used, and collections were carried out at 20 and 42 days of age. Carvacrol and cinnamaldehyde concentrations (mg/kg) were: 0 (control), 50, 100, 150, and 200. Carvacrol and cinnamaldehyde improved apparent metabolizable energy but did not change protein and ether extract digestibility. Supplementation increased intestinal villus height and villi:crypt ratio; in which 100 mg/kg produced the greatest villus height. Serum uric acid levels were lower in birds receiving supplementation. Improvement in the activity of glutathione peroxidase and glutathione-S-transferase was observed, while lower uric acid, thiobarbituric acid reactive substances, and reactive oxygen species levels were observed. Microencapsulated carvacrol and cinnamaldehyde improve apparent metabolizable energy and can be administered in broiler feed without risk to the bird’s health. These supplements may serve as alternative products to aid the performance of commercial poultry.

ABSTRACT The objective of this study was to evaluate whether the addition of the enzymes phytase and xylanase, isolated or associated, in the liquid form after feed pelletization could improve energy utilization and digestibility of calcium and phosphorus by broiler chickens. Three experiments were performed using 120 birds each, divided into five treatments with eight replicates per group (n = 3), identified as: experiment 1 (xylanase: control, 1000 IU, 1500 IU, 2000 IU, 2500 IU), experiment 2 (phytase: control, 500 FTU, 1000 FTU, 1500 FTU, 2000 FTU), experiment 3 (xylanase + phytase: control, 3000 IU + 500 FTU, 3000 IU + 1000 FTU, 3000 IU + 1500 FTU, 3000 IU + 2000 FTU). Samples for digestibility tests were collected at 14 to 21 days of age. Therefore, the inclusion of liquid phytase and liquid phytase + xylanase after pelletization in broiler diets has become a relevant way to reduce the inclusion of inorganic P, which can reduce the cost of feed and P excretion in the environment. Furthermore, it is an interesting strategy to avoid enzyme denaturation in the pelleting process.

ABSTRACT The objective of this study was to evaluate whether the addition of different levels of capsaicin in the diet of female turkeys has beneficial effects on growth performance and the antioxidant and oxidant status in serum and meat. A total of 150 female turkeys were distributed in a completely randomized design with three treatments with five replicates per treatment and ten birds per experimental unit. Treatments were identified as control (without additive); T400 – basal diet containing 400 mg/kg of pepper extract per kg of feed; and T800 – basal diet supplemented with 800 mg/kg of pepper extract per kg of feed. Growth performance was measured on days 1 and 20 of the experiment. Blood samples were collected at 20 days of the experiment for analysis of the oxidant and antioxidant status, and at 20 days, five birds were euthanized per treatment for the analysis of the oxidant and antioxidant status of the meat. The turkeys fed diet supplemented with capsaicin had lower feed intake and better feed:gain ratio. Turkeys in the T800 treatment showed a reduction in serum levels of reactive oxygen species (ROS) and thiobarbituric acid, and this same effect was observed for ROS in their breast meat. Capsaicin supplementation improves feed conversion and reduces feed intake without altering weight gain in female turkeys. Furthermore, the addition of 800 g/ton reduces lipid peroxidation and protein oxidation in the serum and reduces protein oxidation in broiler turkey meat.

ABSTRACT The objective of this study was to evaluate performance, hematological parameters, leukocyte counts, and respiratory microbiota of broilers under heat stress receiving eucalyptus oil supplementation. Cobb broilers (n = 1200) were randomly distributed on the first day of life in a factorial arrangement with additional treatment (2 × 2 + 1) with two periods of oil administration via drinking water (daily, from 18 to 35 days of life) and two periods of oil administration via spray (daily, from 18 to 35 days of age) plus a control treatment, consisting of twelve replications, with 20 animals each. The birds were kept in a controlled environment with constant temperature at 32 °C to induce heat stress by infrared heaters. Eucalyptus oil was supplied by drinking water (1 L of oil to 4000 L of water) or by spray applications with a pump (1 L of oil to 200 L of water). Bird weight was recorded at 42 days of age, along with remaining feed, to determine weight gain, feed intake, and feed conversion. In addition, one blood sample from each bird repetition was collected for hematological and leucocytic evaluation. To assess respiratory microbiota, a tracheal flushing was performed for bacteria counts. There was no difference in performance, hematological parameters, and leukocyte counts, except hematocrit, which was lower in birds that received eucalyptus oil after 18 days of age. No significant differences were observed in the respiratory microbiota comparing oil-treated and -untreated groups. Although it was not possible to verify statistical difference, the birds that received eucalyptus oil via spray plus spray from 18 days old showed lower bacterial counts and absence of isolation of Gram negatives, while the control group was the one with the highest number of Gram negatives. Therefore, eucalyptus oil can be used for heat-stressed broilers without impairing their development.

Em vista da constante evolução do melhoramento genético de frangos de corte, torna-se necessária a determinação das exigências nutricionais dessas aves, para assegurar seu desempenho. Assim sendo, dois experimentos foram realizados, com o objetivo de avaliar diferentes relações de metionina + cistina / lisina digestível sobre o desempenho de frangos de corte, nas fases de 11 a 21 e 22 a 35 dias de idade. O delineamento experimental nas duas fases avaliadas foi o de blocos casualizados, em arranjo fatorial 2x5+2, (2 sexos e 5 diferentes relações met+cis/lis digestível e um tratamento controle para cada sexo), com oito repetições de 23 e 20 aves (COBB 500) por unidade experimental, nas fases descritas. As dietas atenderam às exigências, exceto para metionina + cistina e lisina. Para evitar o excesso de lisina digestível, seu nível foi calculado para 97% do recomendado para todas as fases. O tratamento controle foi adequado em lisina e metionina + cistina. As relações metionina + cistina/lisina digestível, para máximo desempenho de frangos de corte, machos e fêmeas, respectivamente, são de 75,53 e 78,23%, na fase de 11 a 21 dias, e 78,83 e 79,82%, na fase de 22 a 35 dias.

The continual evolution of poultry breeding brings about the need to determine the nutritional requirements of these birds to ensure performance. Therefore, this study carried out two experiments to evaluate different methionine + cystine / digestible lysine ratios on the performance of broiler growing phases starter (11 - 21 days) and growth (22 - 35 days). The experiment evaluated the two phases using a randomized block design in a factorial arrangement 2x5 +2, (2 sexes and 5 different Met + Cys / digestible Lys ratios and a control treatment for each sex) with 8 repetitions of 23 and 20 birds (COBB 500) per experimental unit in the two phases. The diets met the requirements except for methionine + cysteine and lysine. To avoid excess lysine, its level was calculated to be 95% of the recommended level for all phases. The control treatment was adequate in lysine and methionine + cystine. The methionine + cystine / digestible lysine ratios for maximum performance of male and female broiler chicks, respectively, are 75.53 and 78.23% in the phase 11 to 21 days and 78.83 and 79.82% in the phase 22 to 35 days.

A grande evolução da avicultura brasileira e o consequente aumento da produção de resíduos, bem como as exigências impostas pela União Europeia, quanto ao controle da excreção de poluentes, resultam na busca de novos conceitos relativos à nutrição animal. Dentre esses conceitos, destaca-se o uso da proteína ideal, da injeção de nutrientes in ovo, da alimentação dos animais em fases e a suplementação de aditivos como prebióticos, probióticos, enzimas, extratos herbais e minerais orgânicos nas dietas das aves. Várias pesquisas têm sido feitas a fim de comprovar a eficiência dessas práticas de nutrição e muitas delas concluem que a aplicação de estratégias nutricionais tem um significativo potencial de redução da excreção de nutrientes pelos frangos de corte, além de terem ainda, a vantagem de reduzir os custos de produção.

The great evolution of the Brazilian poultry industry, the consequent increased production of waste and the requirements imposed by the European Union concerning the control of the excretion of pollutants result in the search for new concepts of animal nutrition. Among these concepts, we can mention the use of ideal protein, the injection of nutrients in the egg, the animal nutrition based on phases and supplementation of additives such as prebiotics, probiotics, enzymes, herbal extracts and organic minerals in the diets of birds. Several studies have been conducted to prove the effectiveness of these practices of nutrition and many of them conclude that the application of nutritional strategies have significant potential to reduce nutrient excretion by broiler chickens, and have also the advantage of reducing the production costs.

Two experiments were conducted to evaluate different digestible isoleucine/lysine ratios on diets for broiler chickens in the starter (7 to 21 days) and finishing (30 to 43 days) phases. For the tests, the experimental design was of randomized blocks with seven treatments (six different digestible isoleucine/lysine ratios and a control treatment) and eight repetitions of 25 and 20 birds (COBB males) per experimental unit in the starter and finishing phases, respectively. The diets met the requirements, except for isoleucine and lysine. To avoid excess lysine in the experimental diets, the digestible lysine content was calculated to be 87% and 89% of the recommended for the starter and finishing phases, respectively. The control treatment was adequate in lysine and isoleucine. Feed intake, weight gain, feed conversion and carcass yield in the two phases were evaluated. There was quadratic effect of different ratios on feed intake in the finishing phase and on weight gain and feed conversion rate in both phases. There was quadratic effect on breast meat yield and breast fillets in the starter phase, but there was no significant effect on carcass yield in the finishing phase. The digestible isoleucine/lysine ratio recommended for broilers in the starter phase (7 to 21 days) is 66% and for the finishing phase (30 to 43 days), it is 68%.

The objective of this study was to evaluate the effect of feeding herbal extracts for broilers on performance and histology of the intestinal mucosa and its effects on the profiting from the metabolizable energy of experimental diets. For so, two experiments were conducted. In experiment I, the inclusion of different herbal extracts in diets on performance and intestinal histology of broilers was evaluated, and in experiment II, the values of apparent metabolizable energy and metabolizable energy corrected by the nitrogen balance of the experimental diets were studied. Treatments consisted of: positive control diet; positive control + avilamycin; negative control; negative control + 100 ppm of a complex containing three different herbal medicines (pepper, cinnamon and oregano); negative control + 75 ppm garlic extract; negative control + 150 ppm garlic extract. In the performance experiment, which comprised the period of 1 to 40 days of age, 960 male broilers were distributed in a randomized block design, with six treatments and eight replicates, with 20 birds per experimental unit. In experiment II, the method adopted was the traditional of total excreta collection with male broiler chicks in the age of 14 to 24 days, in a completely randomized design, with six treatments and eight replicates with five birds per experimental unit. The intestinal villus height was improved with addition of the composite containing the three herbal extracts; however, crypt depth and villus/crypt ratio were not affected. The use of herbal extract in diets for broilers promotes performance similar to that with the use of antibiotics. Herbal extracts can be incorporated into diets replacing antibiotics without compromising the metabolizable energy of diets, performance or intestinal mucosa for broilers in the period of 1 to 40 days of age.

The assay was carried out to determine the effect of phytase supplementation on performance of broilers from 1 to 21 and 1 to 40 days of age. Twelve hundred and fifty male broilers (Ross) were distributed in a randomized experimental design, with five treatments, 10 repetitions and 25 birds per experimental unit. The treatments consisted of evaluating the phytase supplementation in diets with reductions in nutritional levels, compared with the positive control. The nutrient contents in negative controls one and two were reduced progressively and these diets were supplemented with phytase levels of 250 and 500 ftu/kg of the diet, respectively. Two diets were formulated: pre-starter/starter, 1-21 days, and growth/finishing, from 21 to 40 days). In both phases, with the phytase supplementation in diets that had their nutritional levels reduced (negative control one + 250 ftu and negative control two + 500 ftu), feed intake, weight gain and feed conversion of the birds were similar to the positive control. In the period from 1 to 40 days of age, with the diets supplemented with phytase, the productive efficiency index of the birds was similar to that of the positive control group. Supplementation with 250 ftu/kg and 500 ftu/kg phytase in diets with reduced nutritional levels improved broiler performance, resulting in parameters similar to those shown by broilers fed with the diet with normal levels of nutrients.

Foi realizado um experimento para avaliar os efeitos da inclusão de farelo de girassol em rações para frangos de corte sobre o desempenho, o rendimento de carcaça e dos cortes e a viabilidade econômica. O delineamento experimental foi em blocos casualizados com cinco níveis de farelo de girassol (0, 5, 10, 15 e 20% da dieta basal), oito repetições e 20 aves por unidade experimental. As aves e as rações foram pesadas no início e ao final de cada fase do período experimental (1 a 21 dias e 22 a 42 dias) para obtenção do consumo de ração, do ganho de peso e da conversão alimentar. Duas aves de cada repetição foram abatidas aos 42 dias de idade para avaliação da carcaça. Com a inclusão do farelo de girassol, o consumo diminuiu linearmente na fase inicial (y = 1185,1 - 2,1x; R² = 0,97), enquanto a conversão alimentar melhorou de forma linear no período total (y = 1,6404 - 0,0018x; R² = 0,62) e de forma quadrática na fase inicial (y = 1,3943 - 0,0069x + 0,0002x²; R² = 0,96). Não foi encontrada diferença significativa no rendimento de carcaça e dos cortes. Os melhores desempenhos econômicos foram obtidos quando as aves foram alimentadas com rações contendo 5% de farelo de girassol na fase inicial e 0% na fase de crescimento e no período total. A adição de 20% de farelo de girassol em rações para frangos de corte até os 42 dias de idade não prejudica o desempenho produtivo das aves.

A trial was carried out to evaluate the effect of sunflower meal inclusion in the broiler diets on the performance, carcass yield and cuts and the economics viability. A randomized block experimental design was used, with five treatments and eight replications of 20 birds per experimental unit. Treatments consisted of including 0, 5, 10, 15, or 20% sunflower meal in a basal diet. Birds and diets were weighed at the beginning and at the end of each experimental phase (1 to 21 days and 22 to 42 days) to determine feed intake, weight gain, and the feed:gain ratio. Two birds per replication were slaughtered at 42 days of age for carcass evaluation. Feed intake was linearly reduced in the starter phase (y = 1185.1 - 2.1x; R² = 0.97), with sunflower meal inclusion in the basal diet, and the feed:gain ratio linearly improved in the total period (y = 1.6404 - 0.0018x; R² = 0.62), whereas a quadratic effect on the feed:gain ratio was observed in the starter phase (y = 1.3943 - 0.0069x + 0.0002x²; R² = 0.96). No significant differences were observed for carcass yield and cuts. The best economic performances were achieved when the birds were fed diets containing 5% sunflower meal in the starter phase, and 0% in the grower phase and total period. The inclusion of 20% sunflower meal in the diet of broilers up to 42 days of age did not show harmful effects on performance.