Seare T. Desta

Ensiling characteristics, structural and nonstructural carbohydrate composition and enzymatic digestibility of Napier grass ensiled with additives

Ensiling characteristics, structural and nonstructural carbohydrate composition and enzymatic digestibility (ED) of Napier grass silage was examined. Napier grass ensiled with no additive control, 0.2% formic acid, 0.4% molasses, and 0.3% fibrolytic enzyme for, 7, 30, 60 and 90days. Additives increased lactic acid, soluble carbohydrate and decreased all of lignocellulosic contents except acid detergent lignin and pH than control. The highest value of nonstructural carbohydrate and large reduction in lignocellulosic contents was observed in formic acid and fibrolytic enzyme silage respectively. The content of glucose and fructose showed rapid drop in the first 7days of ensilage. Ensilage decreased lignocellulosic contents and increased ED compared to fresh material. The ED of formic acid and molasses silage was significantly higher than control and fibrolytic enzyme silages in all tested days. In summery the ensiling quality structural and nonstructural carbohydrate and ED value of mature Napier grass silage improved through additives.

Effects of four short-chain fatty acids or salts on the dynamics of nitrogen transformations and intrinsic protease activity of alfalfa silage

BACKGROUND Short-chain fatty salts have been widely used as food and forage preservatives because of their antimicrobial properties. This study evaluated the effects of four chemical compounds with antimicrobial properties on nitrogen transformations and intrinsic protease activity of alfalfa silage. RESULTS Potassium diformate (PD) and formic acid (FA) rapidly reduced silage pH. Silages treated with sodium diacetate (SD) and calcium propionate (CAP) had higher final peptide N concentrations than other silage. The free amino acid N contents in PD and FA treated silages were lower than other silages at all intervals of ensilage. The ammonia N concentrations in FA and PD silages were the lowest, followed by SD and CAP silages. As ensiling progressed, the aminopeptidase activity was completely lost by day 5 for FA and PD silages and inactive by day 7 for SD silage, while it remained active after day 7 for control and CAP silage. The carboxypeptidase activities in FA and PD silages were already reduced below 50% by day 1 of ensiling. CONCLUSION Potassium diformate was as effective as formic acid in depressing the proteolysis, while sodium diacetate and calcium propionate were inferior to formic acid in protecting alfalfa proteins from being hydrolysed.

Characterization of Enterococcus faecalis JF85 and Enterococcus faecium Y83 isolated from Tibetan yak (Bos grunniens) for ensiling Pennisetum sinese

Two bacteria strains with cellulolytic potential isolated from Tibetan yak (Bos grunniens) rumen were identified as Enterococcus faecalis (JF85) and Enterococcus faecium (Y83). Isolates grow well within a range of temperature 15 to 55 °C and pH 3.0-7.0, respectively. Two strains were inoculated with or without Lactobacillus plantarum (Lp) to Pennisetum sinese silage for 90 days. All inoculants increased lactic acid content, decreased pH and lignocellulose contents compared with silage without additives (control). The lowest pH, highest lactic acid and largest reduction in lignocellulose contents were observed in JF85+Lp and Y83+Lp silages. Isolates alone or in combination with Lp significantly increased WSC, mono- and disaccharides contents as compared to the control. Combined addition efficiently improved enzymatic hydrolysis of Pennisetum sinese silage, indicated by higher glucose yield and cellulose convertibility. Pennisetum sinese ensiled with combined additives is a suitable storage and pretreatment method prior to sugars production from energy crop.

Effects of Lactobacillus plantarum and fibrolytic enzyme on the fermentation quality and in vitro digestibility of total mixed rations silage including rape straw

Abstract The aim of the current study was to investigate the effects of a lactic acid bacteria inoculant ( Lactobacillus plantarum, LP), fibrolytic enzyme (EN), combination of LP and EN (LP+EN) on fermentation quality, nutritive characteristics and in vitro digestibility of total mixed ration (TMR) silages containing 0, 7.5 and 15.0% (on dry matter basis) of rape ( Brassica campestris L.) straw (RS) (denoted as CTMR, LTMR and MTMR, respectively). After ensiling for 60 days, TMR silages without additives were well preserved, but MTMR had higher pH than CTMR and LTMR. There were no differences in other parameters of fermentation quality, microbial composition, nutrition and in vitro digestibility between CTMR and LTMR except for yeast and mold number and crude protein (CP) content. CTMR and LTMR silage had higher CP content, in vitro neutral detergent fiber digestibility (IVNDFD) and in vitro acid detergent fiber digestibility (IVADFD), lower acid detergent fiber (ADF) content than MTMR silage. LP and EN decreased pH and increased dry matter (DM) recovery of TMR silages. LP+EN improved the fermentation quality, nutritive characteristics and in vitro digestibility of TMR silages, showed by lower pH, ADF content, higher lactic acid content, in vitro dry matter digestibility (IVDMD) and IVNDFD. Therefore, It was suggested that TMR silage contained 7.5% RS on a DM basis and treated with LP+EN can be as a useful feed for ruminant.

Effects of sodium diacetate on the fermentation profile, chemical composition and aerobic stability of alfalfa silage

Objective The objective of this study was to evaluate the effect of sodium diacetate (SDA) on fermentation profile, chemical composition and aerobic stability of alfalfa (Medicago sativa L.) silage. Methods Fresh alfalfa was ensiled with various concentrations of SDA (0, 3, 5, 7, and 9 g/kg of fresh forage). After 60 days of the ensiling, the samples were collected to examine the fermentative quality, chemical composition and aerobic stability. Results The application of SDA significantly (p<0.05) decreased silage pH with the lowest value in silage with 7 g/kg of SDA. The proliferations of enterobacteria, yeasts, molds and clostridia were inhibited by SDA, resulted in lower ethanol, propionic and butyric acid concentrations and dry matter loss in SDA treated silages than control. The increasing SDA linearly decreased free amino acid N (p<0.001), ammonia N (p = 0.018) and non-protein N (p<0.001), while linearly increased water soluble carbohydrate (p<0.001) and peptide N (p<0.001). It is speculated that SDA accelerated the shift from homofermentative to heterofermentative lactic acid bacteria during the silage fermentation, indicated by lower lactic acid production in SDA-9 than SDA-7 silages after 60 days of ensiling. Alfalfa silages treated with SDA at 7 g/kg had highest Flieg’s point and remained stable more than 9 d during aerobic exposure under humid and hot conditions in southern China. Conclusion SDA may be used as an additive for alfalfa silages at a level of 7 g/kg.

Effects of ethanol, molasses and Lactobacillus plantarum on the fermentation quality, in vitro digestibility and aerobic stability of total mixed ration silages in the Tibetan plateau of China.

In Tibet, it is common practice to make and relocate total mixed ration (TMR) silages before feeding due to the uneven distribution of forages temporally and spatially. This study was conducted to investigate the effects of Lactobacillus plantarum (L), molasses (M) or ethanol (E) on the fermentation quality and aerobic stability of local adaptive TMR silage. After 45 days of ensiling, pH and ammonia nitrogen in inoculated TMR silages were significantly lower than control. During the first 6 days of the aerobic exposure test, a small fluctuation in lactic acid concentration for all TMR silages was observed, and then silages with ethanol continued this trend, while lactic acid in silage without ethanol sharply decreased until the end of the aerobic exposure period. Meanwhile, pH gradually increased along the aerobic exposure; silages treated with ethanol showed lower pH after 9 days of aerobic exposure. The population of yeast gradually increased during 6 days of aerobic exposure, after that an accelerated rise was observed in TMR silages without ethanol. The combinational beneficial effect of L. plantarum and ethanol was found in combined addition of ethanol and Lactobacillus plantarum silages (EL), indicated by intermediate fermentation quality and higher aerobic stability.

Effects of four short-chain fatty acids or salts on fermentation characteristics and aerobic stability of alfalfa (Medicago sativa L.) silage

BACKGROUND The objective of the present study was to evaluate the effects of four chemicals on the fermentation quality and aerobic stability of alfalfa (Medicago sativa L.) silage. Wilted alfalfa was ensiled without additive (control), or with formic acid (FA), potassium diformate (KDF), sodium diacetate (SDA) or calcium propionate (CAP). RESULTS After 60 days of ensiling, the pH values in FA, KDF and SDA silages were lower (P < 0.05) compared to that of control and CAP silages, and chemicals (P < 0.05) decreased butyric acid and ammonia N concentrations and populations of aerobic bacteria and yeasts compared to the control. The SDA and CAP silages had a higher (P < 0.05) lactic acid bacteria content compared to the FA and KDF silages. The SDA and CAP silages had higher (P < 0.05) acetic and propionic acid contents compared to the other silages, respectively. The ammonia N concentrations in the FA and KDF silages were lower compared to the other silages during the first 5 days of aerobic exposure, and then increased sharply to 105 and 100 g kg-1 total N, respectively, which was higher (P < 0.05) than that of the SDA and CAP silages on day 9 of aerobic exposure. Yeasts and aerobic bacteria counts in SDA silage slowly increased and remained at lower levels compared to the other silages after 7 days of aerobic exposure. CONCLUSION Additives prolonged the aerobic stability duration compared to the control, and the SDA and CAP silages remained stable for more than 216 h, followed by the KDF and FA silages (202 and 196 h, respectively).

Effects of calcium propionate on the fermentation quality and aerobic stability of alfalfa silage

Objective To assess the potency of calcium propionate (CAP) used as silage additive, an experiment was carried out to evaluate the effect of CAP on the nitrogen transformation, fermentation quality and aerobic stability of alfalfa silages. Methods Alfalfa was ensiled with four levels of CAP (5, 10, 15, and 20 g/kg of fresh weight [FW]) in laboratory silos for 30 days. After opening, the silages were analyzed for the chemical and microbiological characteristics, and subjected to an aerobic stability test. Results The increasing proportion of CAP did not affect pH, lactic acid (LA) concentrations and yeast counts, while linearly decreased counts of enterobacteria (p = 0.029), molds (p<0.001) and clostridia (p<0.001), and concentrations of acetic acid (p<0.001), propionic acid (p<0.001), butyric acid (p<0.001), and ethanol (p = 0.007), and quadratically (p = 0.001) increased lactic acid bacteria counts. With increasing the proportion of CAP, the dry matter (DM) loss (p<0.001), free amino acid N (p<0.001), ammonia N (p = 0.004), and non-protein N (p<0.001) contents were linearly reduced, whereas DM (p = 0.048), water soluble carbohydrate (p<0.001) and peptide N (p<0.001) contents were linearly increased. The highest Flieg’s point was found in CAP10 (75.9), represented the best fermentation quality. All silages treated with CAP improved aerobic stability as indicated by increased stable hours compared with control. Conclusion The addition of CAP can suppress the undesirable microorganisms during ensiling and exposure to air, thereby improving the fermentation quality and aerobic stability as well as retarding the proteolysis of alfalfa silage. It is suggested that CAP used as an additive is recommended at a level of 10 g/kg FW.

Fermentation quality, in vitro digestibility and aerobic stability of total mixed ration silages prepared with whole-plant corn (Zea mays L.) and hulless barley (Hordeum vulgare L.) straw

This study was carried out to assess the effects of adding Lactobacillus plantarum, molasses or/and ethanol on the fermentation quality, in vitro digestibility and aerobic stability of total mixed ration (TMR) silage, which is well accepted in small-scale dairy farms in Tibet. Total mixed ration were ensiled in laboratory silos (1 L) and treated with (1) no additive (Control), (2) ethanol (E, 25 ml/kg fresh weight (FW)), (3) molasses (M, 30 g/kg FW); (4) Lactobacillus plantarum (L, 106cfu/g FW); (5) ethanol + molasses (EM); and (6) ethanol + Lactobacillus plantarum (EL). After 45 days of ensiling, six silos per treatment were opened for the fermentation quality and in vitro digestibility analyses, whereas 18 silos were used for the aerobic stability test for the following 9 days. All TMR silages were well preserved with dominant lactic acid (LA), low pH and ammonia nitrogen, and negligible propionic and butyric acid. The L and EL silages had the lowest pH and highest LA concentrations. The addition of ethanol did not inhibit silage fermentation as there were no significant differences for the pH, LA, acetic acid, negligible propionic acid or ammonia nitrogen content, lactic acid bacteria and yeast counts between Control and the E silage. During the aerobic stability test, pH increased by 1.39, 1.67, 1.69 and 0.74 for the Control, M, L and EM silages, but only 0.40 and 0.34 for E and EL silages, respectively. Upon exposure to air, the LA concentration in the L silage was evidently (P < 0.05) decreased, whereas LA concentration in the EL silage remained the highest value after the third day of aerobic exposure. Mean populations of aerobic bacteria and yeast in the E and EL silages were lower (P < 0.05) than those of the Control. These findings suggested that L. plantarum is effective in improving fermentation quality of TMR silages. Although the addition of ethanol in our study did not depress the fermentation of the TMR silages, it showed potential to inhibit the aerobic spoilage of TMR silages, either alone or in combination with the L. plantarum. It is concluded that L. plantarum combined with ethanol not only ensures better fermentation but also could improve aerobic stability.