Abstract:
This study was carried out to chemically assess the nutritional value of unfermented and microbially fermented citrus peel meal with a view to suggesting their possible use in animal feeding. Fresh citrus peels (Citrus sinensis) were washed, sundried, ground and inoculated with three different microorganisms; namely Saccharomyces cerevisae, Lactobaccillus delbruckii and Lactobacillus coryneformis; at the rate of single, double and triple combination in a plastic container under aerobic condition. They were fermented for a period of 0, 3 and 7 days. The fermented samples thereafter, were sundried and chemically analyzed. The crude protein (CP) content increased with the mean value of 17.84% as the day of fermentation increased from 0 to 7 days while, the manner of inoculation led to 20.21% - 23.50% increment with a concomitant decrease in crude fibre (CF) by 13.75% and 20.67% as the fermentation days increased from 0 through 3 to 7 days. The manner of inoculation led to a decrease of CF by 8.42% to 45.65% with significant (p<0.01) interaction of the two main effects. The anti-nutritional factors typified by oxalate, phytate and flavanoid decreased as the fermentation days increased (p<.001) with the manner of inoculation. Except for the tannic acid equivalent, the value of the other anti-nutritional factors quantified significantly (p<0.05) depended on the two factors examined. All the fibre fractions (except Acid Detergent Lignin) decreased as the fermentation days increased and with the manner of inoculation (p<.001) with significant interaction (p<.001) of the two factors. The energy values of the fermented citrus peel meal varied (p<0.001). While Phy:Zn molar ratio and [Ca][Phy]:[Zn] decreased with increased in fermentation period and manner of inoculation (p<.001), the Ca:Phy molar ratio increased (p<.001) as the day of fermentation and manner of inoculation increased, suggesting that in the peel’s Ca and Zn are bio-available. In conclusion, fermenting sweet orange (Citrus sinensis) fruit peel, an agro waste, as done in this study, yielded a feeding stuff comparable in nutritive quality to maize, which could be used in animal nutrition
