The objective of this study was to select lactic acid bacteria (LAB) isolated from the rumen fluid and feces of dairy cows, and evaluate their effects on silage quality of alfalfa after 30 or 60 days of ensiling. One hundred and four LAB strains were isolated from rumen fluid and feces of six dairy cows, of which four strains (Lactobacillus plantarum F1, L. plantarum F50, Lactobacillus salivarius L100, and Lactobacillus fermentum L120) and one commercial inoculant (GFG) isolated from forage were employed for further study. The silages treated with F1 had the lowest (P < 0.05) pH value and the highest (P < 0.05) lactic acid (LA) content in all treatments. Besides, higher (P < 0.05) in vitro digestibility was also observed in F1-treated silage after 60 days of ensiling. The microbial analysis showed that the Lactobacillus abundance in the F1-treated silages increased to 60.32%, higher than other treatments (5.12-47.64%). Our research indicated that strain F1 could be an alternative silage inoculant, and dairy cows could be a source for obtaining excellent LAB for ensiling.

The effect of silage additives on ensiling characteristics and nutritive value of Napier grass (Pennisetum purpureum) silages was studied. Napier grass silages were made with no additive, fermented juice of epiphytic lactic acid bacteria (FJLB), molasses or cassava meal. The ensiling characteristics were determined by ensiling Napier grass silages in airtight plastic pouches for 2, 4, 7, 14, 21 and 45 d. The effect of Napier grass silages treated with these additives on voluntary feed intake, digestibility, rumen fermentation and microbial rumen fermentation was determined in 4 fistulated cows using 4×4 Latin square design. The pH value of the treated silages rapidly decreased, and reached to the lowest value within 7 d of the start of fermentation, as compared to the control. Lactic acid content of silages treated with FJLB was stable at 14 d of fermentation and constant until 45 d of ensiling. At 45 d of ensiling, neutral detergent fiber (NDF) and acid detergent fiber (ADF) of silage treated with cassava meal were significantly lower (p<0.05) than the others. In the feeding trial, the intake of silage increased (p<0.05) in the cow fed with the treated silage. Among the treatments, dry matter intake was the lowest in the silage treated with cassava meal. The organic matter, crude protein and NDF digestibility of the silage treated with molasses was higher than the silage without additive and the silage treated with FJLB. The rumen parameters: ruminal pH, ammonia-nitrogen (NH3-N), volatile fatty acid (VFA), blood urea nitrogen (BUN) and bacterial populations were not significantly different among the treatments. In conclusion, these studies confirmed that the applying of molasses improved fermentative quality, feed intake and digestibility of Napier grass.

A fermented juice from macerated napiergrass containing epiphytic lactic bacteria (FJLB) and napiergrass was prepared, mixed with defatted rice bran (FJLB + DRB) or dried green tea waste (FJLB + DTW) and freeze-dried. Silage was treated with FJLB + DRB, FJLB + DTW, DRB or DTW in powder form at levels of 2, 10 and 50 g kg −1 fresh matter (FM). FJLB in liquid form was added at a level of 10 mL kg −1 FM. All treated silages were well preserved, with lower pH, acetic acid and NH 3 -N content and higher lactic acid content than that of the control. Butyric acid was present only in the control silage and those treated with DRB or DTW. Without powdered FJLB additives, napiergrass silages had higher pH values, butyric acid and NH 3 -N content, but low lactic acid content compared with powdered FJLB silages. Increasing the amount of all powdered additives had effect on lactic acid and NH 3 -N content. It may thus be concluded that the powder form of FJLB was as effective in improving the fermentative quality of napiergrass as the liquid form.

Two experiments were conducted to evaluate the effects of fermented juice of epiphytic lactic acid bacteria (FJLB) prepared with glucose, sucrose or molasses as additives on the fermentative quality of guineagrass silage. The numbers of lactic acid bacteria (LAB) in all FJLB increased from 105 c.f.u. mL−1 to 108−109 c.f.u. mL−1 after 2 days of anaerobic incubation. FJLB mixed with 3% of the three sugar substrates were added at various volumes (0.2, 0.5 and 1%[v/w]) in experiment 1. As the volume of FJLB added increased, increases in lactic acid and decreases in butyric acid and the pH value were observed, except when FJLB prepared with molasses was used. In experiment 2, FJLB prepared with various levels of glucose, sucrose and molasses were made and added to guineagrass. The level of lactic acid production in silage was higher (P < 0.05) when treated with glucose‐FJLB than with sucrose‐FJLB or molasses‐FJLB. The fermentative quality of silages tended to increase with increasing levels of sucrose or molasses in the FJLB preparation. We suggest that both increasing the volume of FJLB and increasing the level of sugar substrates in FJLB will produce high fermentative quality in guineagrass silage. Glucose‐FJLB is effective even when prepared with a low level of glucose.

ObjectiveThis study aims to evaluate the chemical composition, fermentation quality and in vitro ruminal fermentation of various ratios and storage periods of liquid brewer’s yeast (LBY) mixed with cassava pulp (CVP).MethodsFour mixtures of fresh LBY and CVP were made (LBY0, LBY10, LBY20, and LBY30 for LBY:CVP at 0:100, 10:90, 20:80, and 30:70, respectively) on a fresh matter basis, in 500 g in plastic bags and stored at 30 to 32°C. After storage, the bags were opened weekly from weeks 0 to 4. Fermentation quality and in vitro gas production (IVGP) were determined, as well as the dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber, acid detergent fiber and acid detergent lignin contents.ResultsThe contents of CP and EE increased, whereas all other components decreased, in proportion to LBY inclusion (p<0.01). The DM and OM contents gradually decreased in weeks 3 and 4 (p<0.05), while EE contents were lowest in week 0. The pH, ammonia nitrogen per total nitrogen (NH3-N/TN) and V-score in each mixture and storage period demonstrated superior fermentation quality (pH≤4.2, NH3-N/TN≤12.5%, and V-score>90%). The pH increased and NH3-N/TN decreased, with proportionate increases of LBY, whereas the pH decreased and NH3-N/TN increased, as the storage periods were extended (p<0.01). Although IVGP decreased in proportion to the amount of LBY inclusion (p<0.01), in vitro organic matter digestibility (IVOMD) was unaffected by the mixture ratios. The highest IVGP and IVOMD were observed in week 0 (p<0.01).ConclusionThe inclusion of LBY (as high as 30%) into CVP improves the chemical composition of the mixture, thereby increasing the CP content, while decreasing IVGP, without decreasing fermentation quality and IVOMD. In addition, a preservation period of up to four weeks can guarantee superior fermentation quality in all types of mixtures. Therefore, we recommend limiting the use of CVP as a feed ingredient, given its low nutritional value and improving feed quality with the inclusion of LBY.