RESUMO
A coupled numerical approach is used to evaluate the influence of pore connectivity and microcracks on leaching kinetics in fully saturated cement paste. The unique advantage of the numerical model is the ability to construct and evaluate a material with controlled properties, which is very difficult under experimental conditions. Our analysis is based on two virtual microstructures, which are different in terms of pore connectivity but the same in terms of porosity and the amount of solid phases. Numerical fracturing was performed on these microstructures. The non-fractured and fractured microstructures were both subjected to chemical leaching. Results show that despite very different material physical properties, for example, pore connectivity and effective diffusivity, the leaching kinetics remain the same as long as the amount of soluble phases, i.e., buffering capacity, is the same. The leaching kinetics also remains the same in the presence of microcracks.
RESUMO
In this study, productive performance, quality of eggs and histological analysis of intestinal villi of the duodenum (length and width) was evaluated in Bovans laying hens of 63 weeks of age, with the addition of butyrate in the diet ( 0, 300, 500 ppm). The results obtained in ten weeks of experimentation showed a response (P < 0.05) on egg production percentaje (86.4, 92.2 and 89.6), egg weight (63.4, 63.4 and 64.1 g), feed consumption/bird/day (111.4, 111.9 and 113.4 g), feed conversion (2.09, 1.95 and 2.03), micro-fractures percentaje (20.8, 14.9 and 12.9), broken eggs percentaje (2.6, 2.1 and 0.6), length of villi (1.15, 1.22 and 1.32 mm) and villi width (0.467, 0.500 and 0.532 mm) to the addition of butyrate. These results indicate the beneficial effect of butyrate in laying hens in the last third of its first production cycle. From information obtained in this study, it is concluded that sodium butyrate on diets at 500 ppm for Bovans laying hens of 63 weeks of age, improves the productive performance, shell quality and intestinal villi integrity.
En el presente estudio se evaluó el comportamiento productivo, calidad del huevo y análisis histológico de vellosidades intestinales de duodeno (largo y ancho) en gallinas de la estirpe Bovans, de 63 semanas de edad, con adición de butirato en la dieta (0, 300, 500 ppm). Los resultados obtenidos en diez semanas de experimentación mostraron respuesta (P < 0.05) en porcentaje de postura (86.4, 92.2 y 89.6), peso del huevo (63.4, 63.4 y 64.1 g) consumo/ave/día (111.4, 111.9 y 113.4 g), conversión alimentaria (2.09, 1.95 y 2.03), de microfracturas (20.8, 14.9 y 12.9), de huevos rotos (2.6, 2.1 y 0.6), longitud de vellosidades (1.15, 1.22 y 1.32 mm) y ancho de vellosidades (0.467, 0.500 y 0.532 mm) a la adición de butirato. Los resultados indican el efecto benéfico del butirato en gallinas ponedoras en el último tercio de su primer ciclo de producción. De la información obtenida en el presente estudio se concluye que el butirato de sodio en dietas a 500 ppm para gallinas Bovans, de 63 semanas de edad, mejora el comportamiento productivo, la calidad del cascarón y la integridad de las vellosidades intestinales.