Testing of a novel dual purpose silage strain combination on various different crops

Abstract

Introduction Homo- and heterofermentative strains are used for fast pH reduction at the beginning of the ensiling process and secure long aerobic stability, respectively. Combining those two groups of lactic acid bacteria is not always delivering the expected result. Recently, a novel Lactococcus lactis O224 DSM11037 strain has been introduced, which is superior in oxygen scavenging and also relatively fast in reducing pH (Hindrichsen et al., 2012). Combining this L. lactis O224 DSM11037 strain with Lactobacillus buchneri DSM 22501 have shown better results on aerobic stability than previously seen with combinations of L. buchneri and high lactate producing strains, such as L. plantarum. Our objective with the current study was to evaluate the effi cacy of the new L. lactis O224 DSM11037/L. buchneri DSM 22501 combination on various forages by measuring both fermentation characteristics and aerobic stability. The additive was compared to an untreated reference in laboratory-scale experiment. Materials and methods Silages were prepared from grass (32.82 % DM; 2.03 % water soluble carbohydrate (WSC) of fresh matter (FM), alfalfa (34.11 % DM; 1.45 % WSC FM), alfalfa/grass (35 % DM; 2.34 % WSC FM) and whole crop maize 38.55 % DM; 2.53 % WSC FM) after treatment with the following LAB combination, SiloSolve FC (TA) L. buchneri DSM22501 and L. lactis O224 DSM11037, Chr. Hansen A/S, Denmark. The application rate was 4 ml inoculant suspension/kg forage targeting 150,000 cfu/g forage. The untreated control (UT) received 4 ml water/kg forage. Herbages were ensiled in 3 l laboratory silos (each treatment and crop was replicated 5 times) and analyzed after 90 d of storage at 20oC. Aerobic stability (AS) was determined by monitoring the temperature increase in silages stored in insulated PVC-tubes at 20 ºC ambient temperature and defi ned as a temperature increase of 3°C above the ambient temperature. Data were statistically ana