Lactobacillus spp. from an inoculant andWeissella and Leuconostoc spp. from forage crops were characterized, and their influence on silage fermentation was studied. Forty-two lactic acid-producing cocci were obtained from forage crops and grasses. All isolates were gram-positive, catalase-negative cocci that produced gas from glucose, and produced more than 90% of their lactate in the d-isomer form. These isolates were divided into groups A and B by sugar fermentation patterns. Two representative strains from the two groups, FG 5 and FG 13, were assigned to the species Weissella paramesenteroides and Leuconostoc pseudomesenteroides, respectively, on the basis of DNA-DNA relatedness. Strains FG 5, FG 13, and SL 1 (Lactobacillus casei), isolated from a commercial inoculant, were used as additives to alfalfa and Italian ryegrass silage preparations. Lactic acid bacterium counts were higher in all additive-treated silages than in the control silage at an early stage of ensiling. During silage fermentation, inoculation with SL 1 more effectively inhibited the growth of aerobic bacteria and clostridia than inoculation with strain FG 5 or FG 13. SL 1-treated silages stored well. However, the control and FG 5- and FG 13-treated silages had a significantly (P < 0.05) higher pH and butyric acid and ammonia nitrogen contents and significantly (P < 0.05) lower lactate content than SL 1-treated silage. Compared with the control silage, SL 1 treatments reduced the proportion ofd-(−)-lactic acid, gas production, and dry matter loss in two kinds of silage, but the FG 5 and FG 13 treatments gave similar values in alfalfa silages and higher values (P < 0.05) in Italian ryegrass silage. The results confirmed that heterofermentative strains of W. paramesenteroides FG 5 andL. pseudomesenteroides FG 13 did not improve silage quality and may cause some fermentation loss.

Two selected strains, Lactobacillus casei FG 1 and Lactobacillus plantarum FG 10 that were isolated from forage crops were used as additives at 1.0 x 10(5) cfu/g of fresh matter to alfalfa, Italian ryegrass, and sorghum, and their effect on fermentation characteristics and aerobic deterioration of silage was studied. The three silages treated with strains FG 1 or FG 10 were well preserved; had significantly lower pH values, butyric acid, propionic acid, and ammonia N concentrations, gas production, and dry matter losses; and had significantly higher contents of residual water-soluble carbohydrates and lactic acid than did the respective control silages. Yeast counts were high in all treated silages and increased rapidly during aerobic exposure. As a result, treated silages spoiled faster upon aerobic exposure than did the respective control silages. Most yeasts isolated from deteriorated silages showed high tolerance to lactic acid but low tolerance to butyric acid, and they were able to grow at low pH conditions and assimilate lactic acid. The results confirmed that L. casei and L. plantarum improved fermentation quality but did not inhibit the growth of silage yeast or aerobic deterioration of the silage.

Pediococcus species isolated from forage crops were characterized, and their application to silage preparation was studied. Most isolates were distributed on forage crops at low frequency. These isolates could be divided into three (A, B, and C) groups by their sugar fermentation patterns. Strains LA 3, LA 35, and LS 5 are representative isolates from groups A, B, and C, respectively. Strains LA 3 and LA 35 had intragroup DNA homology values above 93.6%, showing that they belong to the species Pediococcus acidilactici. Strain LS 5 belonged to Pediococcus pentosaceus on the basis of DNA-DNA relatedness. All three of these strains and strain SL 1 (Lactobacillus casei, isolated from a commercial inoculant) were used as additives to alfalfa and Italian ryegrass silage preparation at two temperatures (25 and 48°C). When stored at 25°C, all of the inoculated silages were well preserved and exhibited significantly (P < 0.05) reduced fermentation losses compared to that of their control in alfalfa and Italian ryegrass silages. When stored at 48°C, silages inoculated with strains LA 3 and LA 35 were also well preserved, with a significantly (P < 0.05) lower pH, butyric acid and ammonia-nitrogen content, gas production, and dry matter loss and significantly (P < 0.05) higher lactate content than the control, but silages inoculated with LS 5 and SL 1 were of poor quality. P. acidilactici LA 3 and LA 35 are considered suitable as potential silage inoculants.

No abstract

Six wethers were used in a replicated 3 x 3 Latin square to study the fermentation quality and nutritive value of total mixed ration (TMR) silages that included wet coffee grounds (WCG). The TMR were prepared using a commercial compound feed, timothy hay, alfalfa hay, dried beet pulp, and a vitamin-mineral supplement in a ratio of 36.5:30:20:12:1.5, respectively, on a DM basis, with timothy hay and alfalfa hay being replaced by WCG at 0, 10, or 20%. All TMR silages, irrespective of WCG addition, were well preserved, with a low pH and ammonia-N content and a high lactic acid content. Intakes by wethers of TMR silages containing 0 and 10% WCG were 96.6 and 94.8 g/kg of BW(0.75), and did not differ (P > 0.05). Intake of TMR silage containing 20% WCG was 76.8 g/kg of BW(0.75), which was equal to 80% of that of the TMR silage with no WCG (quadratic: P < 0.01). Increasing concentrations of WCG in the rations decreased the digestibility of DM, CP, ADF, NDF, and energy, and increased that of ether extract (P < 0.05). The TDN and DE contents of the TMR silages with 0 and 10% WCG were similar, but the TMR silage with 20% WCG was lower (P < 0.05). With progressive increases in WCG concentrations, N intake did not differ, but fecal and urinary N increased linearly (P < 0.001), and retained N decreased linearly (P < 0.001). This study demonstrated that the proportion of WCG to be incorporated into TMR silages should not exceed 10% of the DM.