Standardized ileal digestibility of amino acids of protein sources associated with exogenous enzymes for broilers.

OBJECTIVE: Two experiments were conducted to evaluate the effect of enzyme complex (EC) on the standardized ileal digestibility (SID) of amino acids (AA) in corn gluten meal (60%) (CGM), soy protein concentrate (SPC), dried bovine plasma (DBP), and poultry offal meal (POM). Experiments I and II were conducted with broilers in the pre-starter (1 to 7 days of age) and starter (1 to 21 days of age) phases, respectively. METHODS: The treatments consisted of a protein-free diet (PFD) containing feedstuffs either supplemented with EC (xylanase, amylase, and protease) or not. In Experiment I, a total of 360 one-day-old male Cobb-500 broiler chicks were randomly housed in 45 pens, resulting in five replicates with eight birds each, totalizing eight treatments and one PFD group. In Experiment II a total of 270 one-day-old male Cobb-500 broiler chicks were randomly housed in 45 pens, resulting in five replicates with six birds each, totalizing eight treatments and one PFD group. The PFD groups were used to assess the endogenous AA losses. The birds were slaughtered to collect the ileal content. RESULTS: In the pre-starter phase, the SID of arginine, branched chain-aminoacids, glycine, serine, aspartate, and glutamic acid increased with EC addition. The EC improved the SID of arginine and glutamic acid of CGM; the SID of valine and cystine of SPC; the SID of leucine, glycine, and aspartate of POM and the SID of isoleucine of DBP. In the starter phase, the SID of isoleucine, phenylalanine and glycine increased in EC-supplemented diets. The EC improved the SID of isoleucine of DBP; the SID of phenylalanine of CGM and POM. The SID of AA of SPC was not influenced by the EC. CONCLUSION: The addition of an EC to broiler pre-starter and starter diets is efficient in increasing the SID of AA on SPC, POM, and DBP.

Feeding dry stevia leaf (Stevia rebaudiana) or xylanase improves the hepatic antioxidative status of broiler chickens.

Four diets, formulated with and without stevia and with and without exogenous xylanase, following a 2 × 2 factorial design, were prepared. Each diet was fed ad libitum to birds in eight pens (three birds in each pen) in a randomised block design. It was found that birds fed xylanase grew faster, used the feed more efficiently and had an increased concentration of hepatic α-tocopherol and vitamin E concentrations (P < 0.05). Feeding stevia did not affect growth performance (P > 0.05), but increased hepatic CoQ10 (P = 0.05), lutein, zeaxanthin and total carotenoids (P < 0.001) concentrations. There were no dietary stevia by xylanase interactions (P > 0.05) for any of the studied variables. The results showed that alone, dietary stevia and dietary xylanase can improve the antioxidative status of birds through enhancing dietary antioxidant availability.

Feeding dihydroquercetin and vitamin E to broiler chickens reared at standard and high ambient temperatures.

The use of natural antioxidants, in particular polyphenols such as dihydroquercetin (DHQ), in animal nutrition has recently increased in popularity. This may partly be due to the risk of increased incidences of heat stress associated with raising livestock in warmer ambient temperatures, facilitated by global warming, reducing antioxidant capacity. The current research demonstrates the effect of dietary DHQ, vitaminEand standard or high ambient temperatures on growth performance, energy and nutrient metabolism, gastrointestinal tract (GIT) development, jejunal villus morphometry and antioxidant status in broiler chickens. Each of the four experimental diets was fed to 16 pens of five birds, which were allocated to four rooms (four pens in each room). The temperature in two rooms was maintained at aconstant 35°C (high temperature; HT), and the temperature in the other two rooms was gradually reduced from 27°C at 7 dof age to 22°C at 20 dof age (standard temperature; ST). Rearing birds at HT reduced feed intake, weight gain, weight of small intestine, total GIT, liver, spleen, heart, villus height, villus surface area and lowered blood glutationperoxidase (GSH-Px). Dietary DHQ increased blood GSH-Px and total antioxidant status, increased heart weight and reduced caecal size. When fed separately, DHQ and vitamin E improved hepatic vitamin E concentration. Feeding vitamin Eincreased spleen and liver weights. When fed together, DHQ and vitamin Ereduced villus height, villus height to crypt depth ratio and villus surface area. Temperature and antioxidants did not affect energy and nutrient metabolism. There were no effects of dietary antioxidants on growth performance of broiler chickens and there were no mortalities. At present, it is unclear if feeding antioxidants (in particular DHQ) at different levels, using different dietary formulations, and rearing birds under arange of environmental conditions may be effective at enhancing production performance and bird health in hot ambient climates.

Adição de óleos de copaíba (Copaifera langisdorffii) e sucupira (Pterodon emarginatus) na alimentação de poedeiras: estabilidade lipídica de gema de ovos armazenados em diferentes temperaturas / Effect of dietary supplementation with oils of copaíba (Copaifera langsdorffii) and sucupira (Pterodon emarginatus): lipid oxidation of egg yolks stored in different temperatures

The aim of this study was to evaluate the antioxidant effect of dietary supplementation of plant oil resins in laying hens on the oxidative stability of cooked egg yolk kept at 4ºC for 30 days, and fresh eggs stored under refrigeration (R) at the same temperature for 60 days or kept in room temperature (RT) for 30 days. Hens were fed corn- and soybean-based diets (15% CP and 2,900 kcal kg-1) and supplemented with two levels of Copaifera langsdorffii oil resin (CP-0.03; 0.06 and 0.09%) or Pterodon emarginatus oil resin (SC-0.03 and 0.06%), plus a negative control (CN). At 37 weeks of age, 667 eggs were collected and randomly distributed in different storage conditions, in natura or cooked. The progression of lipid oxidation of egg yolk in natura was quantified in quadruplicate and cooked egg yolks in duplicate, using pool of 3 egg yolks/treatment to analyze TBARS (thiobarbituric acid reactive substances) concentration in quadruplicate. Data analysis was performed using a mixed model and Tukey test, at a 5% significance level. The storage period was considered a longitudinal factor, which varied from five times, for R cooked yolk and TA fresh yolk (0-30 days), to nine times, for R fresh yolk (0-60 days). For fresh eggs stored at RT or R, the supplementation of plant oils did not protect egg yolks from lipid oxidation, compared to NC. However, for cooked egg yolks, the addition of 0.03 and 0.06% of CP oil resin showed antioxidant activity since it reduced lipid oxidation up to day 21 of storage, but had a prooxidant effect for 0.09%. Therefore, it can be concluded that the supplementation of copaíba oil resin had an antioxidant protection of cooked egg lipids...

O objetivo deste trabalho foi avaliar a atividade antioxidante da adição de óleos de copaíba (CP) e sucupira (SC) na alimentação de poedeiras sobre a oxidação lipídica de ovos in natura armazenados em temperatura ambiente (TA) por 30 dias e sob refrigeração (R) a 4ºC por 60 dias, e de gemas cozidas mantidas sob R por 30 dias. As poedeiras foram alimentadas com ração isoproteica (15% PB) e isoenergética (2900 kcal kg-1) à base de milho e farelo de soja, com inclusão de óleo de Copaifera langsdorffii (CP) nas proporções de 0,03; 0,06 e 0,09% ou de Pterodon emarginatus (SC) nas proporções de 0,03 e 0,06%, mais um controle negativo (CN). Foram coletados 667 ovos às 37 semanas de idade e distribuídos aleatoriamente nas diferentes condições de armazenamento (TA ou R). A oxidação dos lipídios de ovos in natura foi quantificada em quadruplicata e das gemas cozidas em duplicata, utilizando-se pool de 3 gemas/tratamento para as análises de TBARS (thiobarbituric acid reactive substances). Os dados foram avaliados adotando um modelo misto e as médias foram comparadas pelo teste de Tukey em 5% de nível de significância e o período de armazenamento foi considerado como um fator longitudinal, variando de cinco tempos no experimento com gemas cozidas, e nos ovos in natura sob R e em TA (0 a 30 dias), até nove tempos sob R (0 a 60 dias). Foi observado que a adição de óleo de CP e SC não reduziu os valores de TBARS em ovos in natura armazenados em TA e sob R em relação ao CN. No armazenamento de gemas cozidas, a inclusão CP (0,03 e 0,06%) protegeu os lipídios até os 21 dias, mas apresentou efeito pró-oxidante quando suplementado a 0,09%. Concluiu-se que a inclusão de até 0,06% de óleorresina de CP nas rações de poedeiras pode proteger os lipídios da gema cozida contra a oxidação durante o armazenamento refrigerado por até 21 dias...