Ruminal digestion and chemical composition of new genotypes of buffelgrass (cenchrus ciliaris l.)

This study evaluates and compares the dry matter production (TDM), chemical composition and effective degradability of dry matter (EDDM), crude protein (EDCP) and neutral detergent fiber (EDNDF) of the Nueces hybrid and five new genotypes of buffelgrass growing in Northeastern Mexico. Potential intake of minerals by cattle consuming the new genotypes was also estimated. All grasses were established in a completely randomized design with three replicates in a rain fed experiment. Plants were hand harvested on Nov. 14, 2000 at Nuevo Leon, Mexico. TDM was not significantly different among genotypes. Crude protein content and cell wall and its components (cellulose, hemicellulose, and lignin) were significantly different among grasses. Also, EDDM, EDCP, and EDNDF were significantly different among the buffelgrass genotypes. The Nueces hybrid had the highest degradability values; in contrast, PI 2 had the lowest values. It seems that high lignin content in new genotypes may negatively influence nutrient digestion in the rumen of sheep. Only the K, Fe and Co contained in all grasses would be sufficient to meet the requirements of grazing cattle. Data of dry matter production and nutritional dynamics, suggest that the new genotypes PI 1 and PI 4 could be considered as good substitutes of the Nueces hybrid for grazing ruminants in northeastern Mexico.