Marcos Barros-Rodríguez

Effects of two intake levels of Leucaena leucocephala on rumen function of sheep

Ruminant production systems based on grass pastures often produce only poor animal performance as expressed by growth or reproductive rates. The nutrient imbalance affecting rumen function is due to low energy and protein intake. The incorporation of leguminous forages such as Leucaena leucocephala, in the diet of ruminants, can stimulate rumen function by providing protein-rich forage (Barros-Rodriguez et al. 2012). This increases the availability of compounds such as ammonia, amino acids and peptides as well as branched short-chain fatty acids, which are produced as a result of degradation of proteins. These substances promote fiber breakdown by acting as ruminal growth activators for rumen bacteria, especially cellulolytic bacteria (Hoover and Stokes 1991). This study aimed to evaluate the effects of 2 intake levels of L. leucocephala (leucaena) on rumen function of sheep fed Pennisetum purpureum.

Effect of intake of diets containing tannins and saponins on in vitro gas production and sheep performance

The aim of this study was to evaluate the effect of the intake of leucaena, Enterolobium cyclocarpum, fruits and a mixture of both feeds on in vitro gas production and in vivo sheep productive performance. The experiment was conducted at the University of Yucatan, Mexico. Twenty-four Pelibuey sheep, 20.28 ± 2.99 kg average liveweight (LW), were used. Animals were randomly assigned to the following experimental treatments: T1: 100% Pennisetum purpureum, T2: 30% Leucaena leucocephala foliage + 70% P. purpureum, T3: 30% E. cyclocarpum fruits + 70% P. purpureum, T4: 30% L. leucocephala foliage + 30% E. cyclocarpum fruits + 40% P. purpureum. Voluntary intake was higher in T4 (grass + leucaena + E. cyclocarpum) (P = 0.0001). Higher LW gain was observed in animals fed with T4 (P = 0.0001) and the lowest LW gains were recorded with grass (T1) and grass + leucaena (T2) (78.9 and 99.2 g/day, respectively). Similarly, the feed conversion efficiency was improved with treatment T4 (P = 0.0030). The in vitro gas production (48 h) was lower by 30 mL/0.5 g fermented DM in T4 compared with the other treatments (P = 0.0001). Apparent DM digestibility was higher in T3 and T4 (P = 0.0005). The protozoa counts were lower in T2, T3 and T4 (P = 0.0001). Higher intake, digestibility and sheep performance with diets containing grass + leucaena + E. cyclocarpum mixture arise from an improved nutritional diet as these sources have higher protein, lower cell walls and higher DM digestibility.

Efecto de la inclusión de Azolla en la dieta de codornices japonesas sobre el consumo de voluntario, digestibilidad aparente y producción de huevos

El objetivo de esta investigacion fue evaluar el efecto de la inclusion de Azolla en la dieta de codornices japonesas sobre el consumo voluntario, digestibilidad aparente de los nutrientes y produccion de huevos. Se utilizaron 240 codornices de 16 semanas de edad iniciando el primer tercio de postura. Las aves se alojaron en 24 jaulas elevadas (10 aves por jaula). Se utilizo un diseno completamente al azar con cuatro tratamientos: T1: 0%, T2: 5%, T3: 10% y T4: 15% de inclusion de Azolla en la dieta por 60 dias. El consumo voluntario de nutrientes fue mayor en los tratamientos con Azolla (p<0.05). El menor rendimiento de huevos g/ave/dia1 fue en T4 (p<0.0001) y la mejor conversion alimenticia fue en T1 y T2 (p<0.0001). La digestibilidad aparente de la materia seca y materia organica no mostro diferencia significativa entre tratamientos. La mayor digestibilidad de proteina cruda fue en T1 (46.1%) y T2 (44.5 %) (p<0.0001), y para fibra detergente neutra fue en T2 (63.6%) (p=0.034). La incorporacion de Azolla en un 5% en la dieta de codornices produce un efecto similar en la produccion de huevos y conversion alimenticia que la dieta control, pudiendo utilizarse como un producto no convencional de bajo costo.