Bromatological and fermentative characteristics of elephant grass silages with the addition of annato by-product

The objective of the present study was to evaluate the nutritional value of elephant grass (Pennisetum purpureum, Schum.) silages with the addition of 0; 4; 8; 12 and 16% of the by-product from SPU annato (Bixa orellana, L.) based on natural matter. A complete random design was used with four replications. The nutritional composition, pH, ammonical nitrogen and lactic, acetic, propyonic and butyric acids were determined. Levels of annato by-product had an increasingly linear effect on contents of dry matter, organic matter, crude protein, ether extract, non-fibrous carbohydrates, propionic acid and ammonical nitrogen. The insoluble nitrogen contents in detergent and acid detergent, calculated on the percentage of total nitrogen and lactic, acetic and butyric acids were not altered by adding the annato by product. The annatto by-product improves the bromatological characteristics of the silages and it can be added in levels up to 16% of the natural matter at the moment of elephant grass ensilage