In Vitro Semi-Solid Fermentation of Two Prickly Pear (Opuntia sp.) Cultivars as Food Supplement for Ruminants

Objective: To increase the protein content of two commercial prickly pear cultivars, fermenting and adding some components, in order to complement the diet of ruminants in areas whose conditions impose limitations upon agriculture. Design/Methodology/Approach: A randomized complete bock design and a factorial treatment arrangement were used to test two prickly pears cultivars (Cristalino (Opuntia albicarpa) and Rojo Pelón (Opuntia ficus-indica)), two particle sizes (chopped and blended), and two non-protein nitrogen (NPN) sources and their combination (1 % urea, 0.1 % ammonium sulfate, and urea + ammonium sulfate). The substrates were fermented for 9 h. One percent yeast (Saccharomyces cerevisiae) and 0.25 % Saccharum spp. treacle were added to the substrates. Results: The levels of the tested factors recorded significant differences (p