CALCIUM, ZINC AND PHYTATE INTERRELATIONSHIPS IN FONIO (Digitaria exilis AND Digitaria iburua) OFFALS

Abstract

Fonio (Digitaria exilis and Digitaria iburua) offals are sought as alternative fibre sources in monogastric feed formulations because they are less expensive, readily and locally available in areas where they are produced. Calcium and zinc in plant sources are usually not available for monogastric animals due to the presence of phytate and monogastrics lack phytase enzyme that will digest it. Therefore, this paper aimed at determining the calcium, zinc and phytate interrelationships of fonio (D. exilis and D. iburua) offals. The molar ratios [Phy]: [Zn], [Ca]: [Phy] and [Ca][Phy]: [Zn] were used. The calculation showed that [Phy]: [Zn] molar ratios of both offals were greater than 10 and less than 15 (critical level is value lower than 10 and greater than 15). Also, the [Ca]: [Phy] molar ratios of both offals were above 6.1 (critical level is value lower than 6.1); and the [Ca][Phy]: [Zn] molar ratios of both offals were also lower than 200 (critical level is value greater than 200). In conclusion it can be predicted that phytate content in fonio offals may not be high to prevent the absorption of calcium and zinc. Therefore, fonio offals are recommended for monogastric species