Predicting the digestibility of Sahelian roughage feeds from the crude protein content in faeces of cattle, sheep and goats using an established first-order exponential function

Abstract

SummaryAn equation predicting organic matter digestibility (OMD) of the diet from faecal crude protein content (FCP) was established by Lukas (2002) with data from cows fed various diets based on roughage of temperate origin. The suitability of this equation to predict OMD of tropical roughages was tested with data from grazing and stall-fed cattle, sheep and goats. The correlation between measured OMD and that estimated from the average FCP of a group of animals consuming the same diet was r=0.91, and the deviation between estimated and measured values averaged 6%. Poor estimates were obtained for feeds with high biological tannin activity. Using the equation provides an easy assessment of OMD of tropical roughages that do not contain biologically traceable amounts of anti-nutrients.