Effect of freeze-dried kefir culture inoculation on nutritional quality, in vitro digestibility, mineral concentrations, and fatty acid composition of white clover silages

Abstract

In this investigation, the aim was to examine the impact of freeze-dried kefir culture (KC) on fermentation characteristics, aerobic stability, nutritive value, in vitro digestibility, some micro- and macronutrient concentration, and fatty acid (FA) composition of white clover (WC) silages. White clover silages were either uninoculated (Con) or inoculated with KC at the following application rates: 10 mg/kg (K10), 50 mg/kg (K50), 100 mg/kg (K100) on a fresh basis, and ensiled in laboratory-scale silos for 270 days, followed by 5 days of aerobic exposure. Changes in fermentation characteristics and nutritive value, in vitro digestibility and gas production (GP), mineral concentrations, and FA composition were assessed in terminal silages. The results showed that KC could effectively reduce neutral detergent fiber, hemicellulose, and ammonia-N contents. The increased acetic acid content of KC-treated silages improved aerobic stability. Freeze-dried kefir culture made no significant difference in cumulative GP and estimated parameters except for 48 and 72 h. It is evidently clear from the findings that KC reduced the K, Na, Se, and B concentrations of WC silages, whereas Ca, Zn, and Fe concentrations increased. In addition, KC significantly increased the proportion of saturated FA (SFA) in WC silages, whereas the proportion of polyunsaturated FA (PUFA) decreased. However, KC did not significantly affect the monounsaturated FA proportion of WC silages. Overall, it is concluded that adding 50-100 mg/kg of KC on a fresh basis is appropriate to improve the nutritional value of WC silages.