Lipid stability of egg and laying performance of Japanese quail feed with extract of guava (Psidium guajava L.).

Two experiments were conducted in order to evaluate the effect of dietary inclusion of guava extract on laying performance and lipid stability of egg of Japanese quails. For the first experiment, 384 Japanese quails with 42 days old were distributed in a completely randomized design with four treatments (0.0; 3.0; 6.0; 9.0 g.kg-1 guava extract), 6 replicates, and 16 birds/replicate. The experimental period lasted 84 days, divided into 4 cycles of 21 days. The parameters evaluated were: feed consumption, egg production, egg mass, feed conversion ratio, egg weight, and egg internal and external qualities. On the second experiment, 400 eggs from Japanese quails fed with diets containing four levels of guava extract were distributed in a completely randomized design with a 4x4 factorial arrangement (guava extract levels and storage time: 0, 9, 18, 27 days) with 5 replicates. Analysis of thiobarbituric acid reactive substances was performed on egg yolks. Data were submitted to regression analysis, using α=0.05. On the first experiment, the laying performance parameters were not influenced by the inclusion of guava extract in the feed, and eggshell thickness decreased linearly. On the second experiment an interaction was observed between the studied factors, affecting lipid oxidation in egg yolks. At nine days of storage, there was a quadratic effect of levels of dietary guava extract on lipid oxidation of yolk, being observed that using 4.8 g.kg-1 of guava extract on feed results in less lipid oxidation.

Results of hatching and rearing broiler chickens in different incubation systems.

Hatchery efficiency is based on hatchability and the number of salable chicks. The hatchery sector has been seeking new alternatives to optimize production rates, including the use of different systems (multistage [MS] or single-stage [SS] machines) to improve incubation conditions. The present study aimed to compare results for hatchability, chick quality, and broiler performance of chicks from 2 incubator systems-MS and SS. The experimental design for hatchability, hatch window, egg weight loss, and chick performance variables was completely randomized with 2 treatments (MS and SS). Performance variables were analyzed as a 2 x 2 factorial arrangement (incubator type x chick sex). Egg weight loss between incubation and transfer was higher for eggs incubated in MS (P < 0.05). Hatchability was higher for eggs incubated in SS (P < 0.05), and chicks in SS had a longer hatch window (P < 0.05). Embryo diagnosis revealed higher final mortality for embryos incubated in MS (P < 0.05), as well as higher percentages of alive and dead pipped and cracked eggs (P < 0.05). Physical quality was better for chicks from SS (P < 0.05). There was no interaction between the studied factors for performance results (P > 0.05). Incubator type did not affect broiler performance for any of the studied ages (P > 0.05), whereas male broilers had better performance than females (P < 0.05). The SS incubation system proved better than the MS system at meeting embryo requirements during embryo development, with better hatching rates and chick quality, although performance variables were not influenced by incubation type.

Effect of dietary inclusion of guanidinoacetic acid on broiler performance / Efecto de la inclusión dietética del ácido guanidinoacético en el desempeño de pollos de engorde / Efeito da inclusão dietética do ácido guanidinoacético no desempenho de frangos de corte

Abstract Background: Creatine and its precursor, guanidinoacetic acid (GAA), decrease protein degradation, avoiding amino acid offset to gluconeogenesis. Objective: To evaluate the inclusion of GAA in the pre-initial diet (1 to 7 days) on performance, digestibility, and blood parameters of broilers from one to 21 days of age. Methods: 252 male broiler chickens aged one day were distributed in a completely randomized design with seven replicates and 12 animals per experimental unit. Treatments consisted of a basal diet, and the basal added with 0.10 and 0.20% GAA. Results: From days 1 to 7, a tendency on improved feed conversion (FC) was observed for broilers receiving 0.20% GAA (p<0.10). Between 7 and 14 days, FC improved, as well as a tendency was observed on improved weight gain in animals fed 0.20% GAA. Animals that received 0.20% GAA showed higher blood concentrations of creatine kinase. Blood creatine and blood glucose did not differ between treatments at day six. The assimilation coefficient of crude protein increased during days 3 to 7 for animals receiving 0.20% GAA. On the period between 17 and 21 days, no difference was observed between treatments. Intestinal weight and length did not show significant differences. Conclusion: Dietary inclusion of 0.20% GAA during the pre-initial stage could improve weight gain and feed conversion of broilers between 1 and 14 days of age.

Resumen Antecedentes: La creatina suministra energía y el ácido guanidinoacético (GAA) es su precursor y actúa como sustrato energético, reduciendo la degradación proteica y evitando el desvío de aminoácidos para gluconeogénesis. Objetivo: Evaluar el GAA en la dieta de pre-iniciación (1 a 7 dias) sobre el desempeño, la digestibilidad y los parámetros sanguíneos de pollos entre 1 y 21 dias de edad. Métodos: Se utilizaron 252 pollitos de engorde machos de un día de edad, distribuidos en un diseño completamente al azar, con siete repeticiones y 12 aves por unidad experimental. Los tratamientos consistieron en: ración basal y ración basal adicionada con 0,10 y 0,20% de GAA. Resultados: En el período de 1 a 7 días se observó una tendencia de mejora de la conversión alimenticia (FC) en las aves que recibieron 0,20% de GAA (p<0,10). De 7 a 14 días hubo mejoría en FC y tendencia de mejora en ganancia de peso de los animales que recibieron 0,20% de GAA. Los animales que recibieron 0,20% de GAA presentaron mayor concentración sanguínea de creatina quinasa. La creatinina y la glucosa sanguínea a los seis días no difirieron entre los tratamientos. El coeficiente de metabolización de la proteína bruta aumentó en el período de 3 a 7 días en los animales que recibieron 0,20% de GAA. Para el período de 17 a 21 días no hubo diferencia entre los tratamientos. Para peso y longitud del intestino no se presentaron diferencias significativas. Conclusión: El GAA a un nivel de 0,20% en la dieta pre- inicial podria mejorar la ganancia de peso, y la conversión alimenticia en el período de 1 a 14 días de edad en pollos de engorde.

Resumo Antecedentes: A creatina é uma substância que fornece energia e o ácido guanidinoacético (GAA) é seu precursor atuando como substrato energético, menor degradação proteica evitando o desvio de aminoácidos para gliconeogênese. Objetivo: Avaliar o GAA em dietas pré-iniciais sobre o desempenho, a digestibilidade e parâmetros sanguíneos. Métodos: Foram utilizados 252 pintos de corte machos de um a 21 dias de idade distribuído sem delineamento inteiramente casualizado, sete repetições e 12 aves por unidade experimental. Os tratamentos consistiram: ração basal e rações com 0,10 e 0,20% de GAA. Resultados: No período de 1 a 7 dias foi observada tendência de melhora da conversão alimentar (FC) (p<0,10) quando as aves receberam 0,20% de GAA. No período de 7 a 14 dias houve melhora na FC e tendência de melhora do ganho de peso dos animais que receberam 0,20% de GAA. Animais que receberam 0,20% de GAA apresentaram concentração sanguínea da enzima creatina quinase maior. A creatinina sanguínea aos seis dias e glicose sanguínea não diferiram entre os tratamentos. O coeficiente de metabolização da proteína bruta foi aumentado no período de 3 a 7 dias para animais que receberam 0,20% de GAA, para o período de 17 a 21 dias não houve diferença entre os tratamentos. Peso e comprimento do intestino não apresentaram diferenças significativas. Conclusão: O GAA em nível de 0,20% na dieta pré-inicial melhoram o ganho de peso, e a conversão alimentar no período de 1 a 14 dias de idade em frangos.