Effect Of Lactobacillus Plantarum And Lactobacillus Buchneri On The Quality,Aerobic Stability Of Italian Ryegrass(Loium Multiflorum Lam.)Silage

Italian Ryegrass(Loium multiflorum Lam.)has the largest cultivated area in southwest of China,whereas the aerobic deterioration of Italian Ryegrass silage is a vital problem in subtropical areas and it has a detrimental effect on both local feed production and animal health.Besides,the number of lactic acid bacteria on Italian Ryegrass is low and lactic aicd-fermentation is not sufficient,decreasing the quality of silage.Four treatments(Lactobacillus plantarum,L.plantarum;Lactobacillus buchneri,L.buchneri;both;Control)were arranged so as to improve the quality and aerobic stability of Italian Ryegrass silage.The inoculant number was applied at 2×106 colony forming units/g.Samples were analyzed for fermentation quality on 2,5,7,16,32,and 45d of fermentation,respectively;the nutritive value and safety quality were investigated on 45d of fermentation;after 45d of fermentation,the silages were subjected to an aerobic stability test lasting 5 d.The results of this experiment were as follows.1.Fermentation quality of silageL.plantarum treatment had lower pH compared with L.buchneri on 5,7,16,32,and 45d of fermentation(P<0.05);L.plantarum treatment had lower pH compared with Control on 5 and 16 d of fermentation(P<0.05);the silages treated with L.plantarum had a little lower pH compared to the combination of L.plantarum and L.buchneri during the fermentation but the differences were not significant(P>0.05);the combination of L.plantarum and L.buchneri lowered pH compared with L.buchneri but the differences were not significant(P>0.05).L.buchneri or in combination with L.plantarum treatment had higher concentrations of acetic acid compared to other treatments during the fermentation(P<0.05),and L.buchneri treatment had higher concentrations of acetic acid compared to the combination of L.plantarum and L.buchneri during the fermentation(P<0.05);the silages treated with L.plantarum had lower concentrations of acetic acid during the fermentation in comparison with Control(P<0.05).The silages treated with L.plantarum or the combination of L.plantarum and L.buchneri had higher concentrations of lactic acid in comparison with other treatments(P<0.05),and the silages treated with L.plantarum had higher concentrations of lactic acid in comparison with the combination of L.plantarum and L.buchneri(P<0.05);the silages with Control had higher concentrations of lactic acid in comparison with L.buchneri(P<0.05).The silages treated with L.plantarum or in combination with L.buchneri had lower concentrations of ammonia-nitrogen in comparison with other treatments on 2,5,16,32 and 45 of fermentation(P<0.05)and the silages treated with L.plantaru,m had lower concentrations of ammonia-nitrogen in comparison with the combination of L.plantarum and L.buchneri but the differences were not significant(P>0.05).2.Nutritive value of silageThe differences on crude protein among all treatments were not significant(P>0.05);the silages treated with the combination of L.plantarum and L.buchneri had a little lower concentrations of crude protein in comparison with L.plantarum and L.buchneri.The differences on acid detergent fiber among all treatments were not significant(P>0.05);the silages treated with the combination of L.plantarum and L.buchneri had a little lower concentrations of acid detergent fiber compared with other treatments and the neutral detergent fiber in silages treated with the combination of L.plantarum and L.buchneri had similar law.The silages with Control had higher concentrations of water soluble carbohydrates in comparison with other treatments(P<0.05),and the differences on water soluble carbohydrates among other treatments were not significant(P>0.05).3.Safety quality of silageThe silages with Control had the highest concentrations of nitrate(66.46 mg/kg,DM)and had higher concentrations of nitrate compared with other treatments(P<0.05);The silages treated with L.lantarum had lower concentrations of nitrate compared with L buchneri or the combination of L.plantarum and L.buchneri(P<0.05)but the differences between L.buchneri and the combination of L.plantarum and L.buchneri were not significant(P>0.05).The silages with Control had the highest concentrations of nitrite(1.48 mg/kg,DM)and had higher concentrations of nitrite compared with other treatments(P<0.05),but the differences among other treatments were not significant(P>0.05).4.Aerobic stability of silageThe silages treated with L.buchneri or in combination with L.plantarum had lower pH compared with other treatments(P<0.05),and the silages treated with L.buchneri had a little lower pH compared with the combination of L.plantarum and L.buchneri but the differences were not significant(P>0.05).The silages treated with L.plantarum had the largest concentrations of CO2 in all silages and had higher concentrations of CO2(59.26 g/kg,DM)compared with other treatments(P<0.05).The silages treated with L.buchneri had the largest number of lactic acid bacteria and the silages with Control had the smallest number of lactic acid bacteria in all silages;the silages treated with the combination of L.plantarum and L.buchneri had a larger number of lactic acid bacteria compared with Control and L.plantarum(P<0.05).The silages treated with L.buchneri or in combination with L.plantarum had a smaller number of yeasts compared with other treatments(P<0.05),and the silages treated with L.buchneri had a little smaller number of yeasts compared with the combination of L.plantarum and L.buchneri but the differences were not significant(P>0.05);the silages treated with L.plantarum had the largest number of yeasts in all silages and the silages with Control had a larger number of yeasts,too.The silages treated with L.buchneri or in combination with L.plantarum had a smaller number of molds compared with other treatments(P<0.05),and the silages treated with L.buchneri had a little smaller number of molds compared with the combination of L.plantarum and L.buchneri but the differences were not significant(P>0.05);the silages treated with L.plantarum had the largest number of molds in all silages and the silages with Control had a larger number of molds,too.In general,L.plantarum treatment improved the fermentation quality and lowered the concentrations of both nitrate and nitrite remarkably in Italian Ryegrass silage;L.buchneri treatment improved the aerobic stability and lowered the concentrations of both nitrate and nitrite remarkably of silage;the combination of L.plantarum and L.buchneri treatment improved the fermentatin quality and aerobic stability,and lowered the concentrations of both nitrate and nitrite remarkably of silage.The effects of adding both L.plantarum and L.buchneri on Italian Ryegrass silage were better than other treatments.Therefore,the combination of L.plantarum and L.buchneri can be explored and applied to practical production of Italian Ryegrass silage in subtropical areas.