Potential of Tunisian carob pulp as feed for ruminants: chemical composition and in vitro assessment

The nutritive value of the carob fruits harvested from ten different geographic regions of the North and the Center of Tunisia was assessed on the basis of chemical composition and in vitro rumen fermentation kinetic. Results showed that the chemical composition (ash, crude protein, fat, and sugar) of carob pods was highly influenced by geographic origin. Neutral detergent fiber varied from 24.37 to 35.58 g/100 g DM, acid detergent fiber from 13.24 to 25.15 g/100 g DM, and acid detergent lignin from 4.72 to 11.09 g/100 g DM. Total phenol, flavonoids, and condensed tannin contents varied from 2.55 to 6.84 g gallic acid equivalents (GAE)/100 g DM, from 74.89 to 276.51, and from 0.23 to 1.63 mg catechin equivalents (CE)/100 g DM, respectively. The samples varied widely in asymptotic gas production (66.6–86.34 ml/300 mg DM). The calculated metabolizable energy and digestible organic matter contents of carob pods ranged from 65.09 to 84.65% and 9.84 to 12.82 MJ/kg DM, respectively.