Effects of Three Additives on the Fermentation Quality of Alfalfa Silage

In order to study the effects of three different additives on the silage quality of alfalfas,the second cut Algongum alfalfa with 70% moisture content were ensiled with addding Radix astragalus(0,5,10 g·kg-1),formic acid(0,6 mL·kg-1),sucrose(0,20 g·kg-1),respectively.At the end of ensiling period(45 days),the silages were sampled and the fermentation quality,chemical composition and LAB counts were analyzed.Results showed that the pH values of silages were significantly lower in all additive treatments(5 g·kg-1 Radix astragalus except) in comparison with control(P0.01).Lactic acid contents and lactic acid/acetic acid ratios showed significantly higher than control(P0.05).NH3-N/total N ratios in all additive treatments(except sucrose) were significantly decreased(P0.05).The effect of formic acid on NH3-N/total N ratios was better than Radix astragalus.However,formic acid had a certain corrosive.Lactic acid bacteria were significantly increased in 10 g·kg-1 Radix astragalus treatment(P0.05).From a safety point of view and silage quality considerations,the 10 g·kg-1 of Radix astragalus was recommended as silage additives.