Wilted Alfalfa Silage Research Articles

Effects of temperature and lactic acid Bacteria additives on the quality and microbial community of wilted alfalfa silage

This study investigated the influence of different temperatures (35℃ High temperature and average indoor ambient temperature of 25℃) and lactic acid bacterial additives (Lactiplantibacillus plantarym, Lentilactobacillus buchneri, or a combination of Lactiplantibacillus plantarym and Lentilactobacillus buchneri) on the chemical composition, fermentation quality, and microbial community of alfalfa silage feed. After a 60-day ensiling period, a significant interaction between temperature and additives was observed, affecting the dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) of the silage feed (p < 0.05). Temperature had a highly significant impact on the pH value of the silage feed (p < 0.0001). However, the effect of temperature on lactic acid, acetic acid, propionic acid, and butyric acid was not significant (p > 0.05), while the inoculation of additives had a significant effect on lactic acid, acetic acid, and butyric acid (p > 0.05). As for the dynamic changes of microbial community after silage, the addition of three kinds of bacteria increased the abundance of lactobacillus. Among all treatment groups, the treatment group using complex bacteria had the best fermentation effect, indicating that the effect of complex lactic acid bacteria was better than that of single bacteria in high temperature fermentation. In summary, this study explained the effects of different temperatures and lactic acid bacterial additives on alfalfa fermentation quality and microbial community, and improved our understanding of the mechanism of alfalfa related silage at high temperatures.

Effects of Ensiling Density on the Fermentation Profile and Aerobic Stability of Wilted Alfalfa Silage

Silage quality and aerobic stability are the key factors affecting the utilization efficiency of silage feed, and ensiling density stands as the fundamental principle of silage making. The experiment presented here evaluates the effects of ensiling density on the silage quality and aerobic stability of alfalfa silage. In this experiment, alfalfa was harvested, wilted, chopped, and subsequently packed into 10 L laboratory silos. The ensiling densities were set to 800 g/L, 700 g/L, and 600 g/L, respectively, with three replicates in each group. Sampling and analysis were carried out at 45 days of silage and 8 days of aerobic exposure. The results showed that ensiling density significantly (p &lt; 0.05) affected the content of ammonia nitrogen, Flieg score, the counts of yeast, and mold. After 45 days of ensiling, 800 g/L silage had the highest contents of dry matter, water-soluble carbohydrates, crude protein, lactic acid, and total organic acids, and the lowest pH and ammonia nitrogen compared to the 700 g/L and 600 g/L silage (p &lt; 0.05). The Flieg score of 800 g/L silage was higher than those of the 700 g/L and 600 g/L silage. The counts of yeast and mold of 800 g/L silage was significantly lower than those of the 700 g/L and 600 g/L silage. During aerobic exposure, a consistent decrease in lactic acid and an increase in pH were observed among all silages. The aerobic stability of 800 g/L silage (156 h) was significantly higher than that in the 700 g/L (136 h) and 600 g/L silage (111 h). It was suggested that the increasing ensiling density above 800 g/L was an effective method to improve both the silage quality and the aerobic stability of alfalfa silage.

Dynamics of the bacterial communities and predicted functional profiles in wilted alfalfa silage.

To investigate the fermentation characteristics, bacterial community and predicted functional profiles during the ensiling of wilted alfalfa (Medicago sativa L.). First-cutting alfalfa was harvested at the early bloom stage, wilted for 6h, and ensiled in laboratory-scale silos (1L capacity). Triplicate silos were sampled after 1, 3, 7, 15, 30 and 60days of ensiling, respectively. The bacterial communities of wilted alfalfa and silages on day3 and 60 were assessed through high throughput sequencing technology, and their functional characteristics were evaluated according to the Kyoto Encyclopedia of Genes and Genomes using Tax4Fun. After 60days of ensiling, alfalfa silage showed a moderate fermentation quality, indicated by high lactic acid (56.7gkg-1 dry matter [DM]) and acetic acid (39.4gkg-1 DM) contents, and low concentrations of butyric acid (2.12gkg-1 DM) and ammonia nitrogen (128gkg-1 total nitrogen). Lactobacillus rapidly became predominant on day3 and increased to 60.4% on day60. Results of functional prediction analyses showed that the metabolism of amino acid, energy, cofactors and vitamins were reduced, while metabolism of nucleotide and carbohydrate were increased during ensiling. Fructokinase, 1-phosphofructokinase and pyruvate kinase played important roles in producing lactic acid. The production of acetic acid may be correlated with the enhancement of 6-phosphogluconate dehydrogenase and acetyl-CoA synthetase. Knowledge regarding bacterial dynamics and their metabolic pathways during alfalfa ensiling is important for understanding the fermentation process and may contribute to the production of nutritious and stable alfalfa silage. High throughput sequencing technology combined with 16S rRNA gene-predicted functional analyses could provide a new and comprehensive insight into bacterial community dynamics and functional profiles to further improve the silage quality.

Fermentative profile and lactic acid bacterial dynamics in non-wilted and wilted alfalfa silage in tropical conditions.

This study was conducted to evaluate the fermentative profile and microbial populations of wilted and non-wilted alfalfa silages ensiled with or without inoculant and the population dynamics of lactic acid bacteria (LAB) of wilted alfalfa plant and theirs silage. A 2 × 2 × 6 factorial arrangement was used, with the absence or presence of wilting (W), with and without bacterial inoculant (I) and six fermentation periods (P) (1, 3, 7, 14, 28 and 56 days), in a completely randomized design, with three replicates. The alfalfa was slightly wilted for 6h and increased the dry matter content from 133.9 to 233.4g/kg. It was performed the cultivation, followed by the isolation of LAB from samples of alfalfa forage before ensiling and its silage only in non-inoculated silages, after different fermentation periods. DNA was extracted from the isolated strains of LAB; the 16S rRNA gene sequences were amplified by PCR and the sequences were compared to those available from the GenBank database. Wilting provided silages with lower pH, ammonia nitrogen and acetic acid concentrations. The wilting process did not alter the amount of LAB; however, it affected the LAB diversity of the silages. The Lactobacillus plantarum was the predominant species in non-wilted and wilted silages.

Comparative microbiota assessment of wilted Italian ryegrass, whole crop corn, and wilted alfalfa silage using denaturing gradient gel electrophoresis and next-generation sequencing.

The microbiota of pre-ensiled crop and silage were examined using denaturing gradient gel electrophoresis (DGGE) and next-generation sequencing (NGS). Wilted Italian ryegrass (IR), whole crop corn (WC), and wilted alfalfa (AL) silages stored for 2months were examined. All silages contained lactic acid as a predominant fermentation product. Across the three crop species, DGGE detected 36 and 28 bands, and NGS identified 253 and 259 genera in the pre-ensiled crops and silages, respectively. The NGS demonstrated that, although lactic acid bacteria (LAB) became prevalent in all silages after 2months of storage, the major groups were different between crops: Leuconostoc spp. and Pediococcus spp. for IR silage, Lactobacillus spp. for WC silage, and Enterococcus spp. for AL silage. The predominant silage LAB genera were also detected by DGGE, but the presence of diverse non-LAB species in pre-ensiled crops was far better detected by NGS. Likewise, good survival of Agrobacterium spp., Methylobacterium spp., and Sphingomonas spp. in IR and AL silages was demonstrated by NGS. The diversity of the microbiota described by principal coordinate analysis was similar between DGGE and NGS. Our finding that analysis of pre-ensiled crop microbiota did not help predict silage microbiota was true for both DGGE and NGS.

Performance, Ruminal Fermentation, and Site of Starch Digestion in Early Lactation Cows Fed Corn Grain Harvested and Processed Differently1,2

Two experiments were conducted to assess the effects of corn grain processing on performance, ruminal fermentation, and starch digestion in early lactation dairy cows. Diets were based on wilted alfalfa silage and high moisture or dry corn grain that was either ground or rolled. Thirty-four cows (17 multiparous) were used to measure effects on intake and lactational performance in a free-stall environment during wk 2 to 15 postpartum. Grinding increased dry matter intake, particularly for cows fed diets containing dry corn, and tended to increase yields of milk, protein, lactose, and SNF. Cow performance was not affected by the moisture content of the corn grain.In the digestion experiment, six cows (43 d of lactation) with ruminal, duodenal, and ileal cannulas were used to measure ruminal and intestinal digestion. Starch digestion in the rumen and small intestine was greater for high moisture corn, but disappearance of starch in the large intestine was greater for dry corn. Both the grinding process and the high moisture content of the corn increased starch digestibility in the total tract. Flow of microbial N in the duodenum was not affected by treatment. High moisture corn increased starch digestion in the rumen and total tract and enhanced ruminal fermentation as indicated by increased volatile fatty acids and decreased NH3 concentrations in the rumen. In the production experiment, however, only grinding improved the value of corn; ensiling at high moisture content had little effect.

Response of Lactating Cows to Methionine or Methionine Plus Lysine Added to High Protein Diets Based on Alfalfa and Heated Soybeans

Lactation diets based on wilted alfalfa silage and heated whole soybeans are common in the mid-western US. We examined the milk production response of multiparous Holstein cows to the addition of ruminally protected methionine at two percentages to a basal total mixed ration. An additional total mixed ration included both methionine and lysine supplementation. Sixteen Holstein cows in early lactation were used in a replicated 4 x 4 Latin square design with 21-d periods. Milk production, milk composition, and dry matter intake were determined for the last 5 d of each period. Milk production (41.5 kg/d), dry matter intake (25.9 kg/d), and milk fat concentration (3.26%) were unaffected by the supplementation of amino acids. The addition of methionine increased milk protein concentration and yield linearly. Each gram of methionine increased milk protein yield by 4g, and milk protein concentration increased from 2.89 to 2.99% with the addition of 10.5 g/d of methionine. The proportion of casein N in total milk N was unaffected by treatment. The addition of lysine did not elicit a response. Total mixed rations based on alfalfa haylage, heated soybeans, and animal proteins were clearly limited by their methionine content but were adequate in their lysine content.

Effect of a microbial inoculant (Ecosyl ™ and/or a glycopeptide antibiotic (vancomycin) on fermentation and aerobic stability of wilted alfalfa silage

First cutting alfalfa was wilted (420 g dry matter kg −1) and was untreated (control) or treated with a microbial inoculant (Ecosyl ™, Lactobacillus plantarum), a glycopeptide antibiotic (vancomycin, 50 or 150 ppm), or combinations of inoculant and antibiotic before ensiling. Microbial inoculation increased initial counts of lactic acid bacteria from approximately 3.5 to 4.9 log 10 cfu g −1 forage. Inoculation markedly improved fermentation as evident by lower silage pH ( P < 0.01), acetic acid ( P < 0.05) and NH 3-N ( P < 0.05) contents and greater amounts of lactic acid after 56 days of ensiling. Inoculation also caused a rapid decrease in coliform bacteria and yeasts and molds. Treatment with vancomycin resulted in an immediate decrease in coliform bacteria and a tendency for lower yeast and molds throughout ensiling. Antibiotic-treated silage also had a lower silage pH ( P < 0.01) relative to control silage in the early, but not the later stages of ensiling. Other aspects of fermentation were not consistently improved by vancomycin. Silages treated with both inoculant and antibiotic had fermentations similar to silages treated only with the inoculant. No additive effects of inoculant and antibiotic were detected. The pH of control silage and silage treated only with inoculant was stable up to 4 days of aerobic exposure. However, silage treated with inoculant plus antibiotic had a reduced aerobic stability as pH increased to above pH 6, and total yeasts and molds were more than 6.5 log 10 cfu g −1 silage after 4 days of aerobic exposure.

SIMULATION OF THE EFFECT OF ADDITIVES ON AEROBIC STABILITY OF ALFALFA AND CORN SILAGES

ABSTRACT Simulation models of silage fermentation and aerobic deterioration, previously developed and validated, are used to study the effects of varying application rates of inoculants, sugars, amylases, formic acid, and propionic acid on silage composition and resistance to heating in air (aerobic stability). Inoculants which reduce silage pH and increase the ratio of lactic to acetic acids are predicted to increase slightly the aerobic stability of 35% dry matter (DM) corn silage but to have minimal effects on the stability of 20, 35, and 45% DM alfalfa silage. Sugars and amylases may extend the fermentation process in alfalfa when the concentration of water-soluble carbohydrates (WSC) limits fermentation; their effect on aerobic stability is variable depending on whether there is residual WSC after fermentation. Formic acid, which inhibits fermentation by reducing pH, is predicted to have no effect on stability of wilted alfalfa silage; on unwilted silage, stability is reduced at application rates exceeding 1.3% of DM. Propionic acid is predicted to increase stability in proportion to application rate, and is the only additive in this study to have a substantial effect on stability. Management practices which exclude oxygen during filling and storage and result in lower fungal concentrations are predicted to increase aerobic stability and the effectiveness of additives which improve stability.

COMPARISON OF WILTED-ALFALFA SILAGE AND ALFALFA HAY PRESERVED WITH PROPIONIC ACID IN CORN-SILAGE-BASED DIETS FOR MILKING COWS

Thirty cows (9 uniparous and 21 multiparous) were fed three diets during weeks 5–16 of lactation. The dietary ingredients were adjusted weekly to reflect their oven dry matter (DM). The control diet was a low-fiber diet containing urea-treated corn silage (UCS), well-dried alfalfa hay and buffered concentrate (525:125:350 DM basis). The two test diets contained corn silage and either wilted-alfalfa silage (WAS) or alfalfa hay treated with propionic acid (PAH) and concentrate (300:300:400 DM basis). For the three blended diets, acid detergent fiber (169, 195 and 212 g kg−1 DM) and digestible energy (12.73, 12.50 and 12.25 MJ kg−1 DM) were different (P &lt; 0.05). The crude protein content of the WAS diet was higher (P &lt; 0.05) than that of the PAH diet (164 vs. 154 g kg−1 DM). Average DM intakes (21.8, 22.5 and 21.2 kg d−1) and solids-corrected milk yields (26.9, 27.9 and 26.6 kg d−1) were similar for the three treatments. Also there was no treatment effect (P &gt; 0.05) on milk composition and acetate/propionate ratios of rumen fluid. Thus WAS and PAH diets supported similar production and equalled the low fiber control diet. Key words: Lactation, urea, corn silage, alfalfa, wilted silage, propionic acid treatment.

Wet Corn Gluten Feed as a Supplement for Lactating Dairy Cattle and Growing Heifers

A lactation trial and a heifer growth trial were conducted to evaluate use of wet corn gluten feed by dairy herds. Twelve multiparous and 4 primiparous Holsteins were assigned to 4×4 Latin squares blocked according to previous production or parity. Animals received increasing amounts of wet corn gluten feed, up to 36% of ration DM, in place of a dry corn and soybean meal concentrate mixture. Each kilogram of wet corn gluten feed DM replaced .9kg concentrate DM. Diets were based on ensiled forage with 33% of forage DM from wilted alfalfa silage and the remainder from corn silage. Forage and supplement were fed separately. Milk production, composition, and DM intake were not affected by increased feeding of wet corn gluten feed. Higher producing cows performed well on this feed. Wet corn gluten feed was generally acceptable when fed separately, but two animals refused sizable portions when fed the highest amount. Wet corn gluten feed can be utilized in traditional stall feeding of dairy cattle, and individual feeding should allow better management of this feed resource by limiting the amount offered to cattle that find it unpalatable. Wet corn gluten feed is also an adequate supplement for raising dairy replacements, allowing more rapid utilization of this perishable feed resource by the dairy herd.

Particle Size Reduction of Alfalfa Silage Did Not Alter Nutritional Quality of High Forage Diets for Dairy Cattle

Twelve multiparous, lactating Holsteins were fed an energy adequate diet (50% wilted alfalfa silage) and two isonitrogenous diets containing 80% of the same silage. The two 80% alfalfa diets were identical in all respects except that for one diet 38% of the alfalfa silage was rechopped after fermentation to reduce the particle length from 5.63 to 3.12mm. Feeding the 80% alfalfa diets decreased milk production due to limitation of digestible energy intake. Under conditions of energy restriction, reduction of particle size of alfalfa silage after fermentation did not result in any changes in feed intake, feed digestibility, or milk production. The results do not preclude the possibility of some changes for intake or digestibility with more extensive reductions in particle length of alfalfa silage. However, because the extent of forage particle size reduction is limited by nutritional and economic constraints, the results of this study indicate that there is no practical advantage to reducing the particle size of fermented alfalfa beyond that required for adequate fermentation.

COMPARISON OF WILTED SILAGES OF ALFALFA CUT AT TWO STAGES OF MATURITY WITH FORMIC-ACID-TREATED SILAGE FROM EARLY-CUT ALFALFA

First cut alfalfa was harvested at early bloom and stored as early-cut formic-acid-treated silage (EFS) and early-cut wilted silage (EWS). Late-cut wilted alfalfa silage (LWS) was harvested 15 days later. Dry matter (DM) yields were 2.91, 2.82 and 3.12 tonnes/ha, respectively, for EFS, EWS and LWS. In the same order, for feeding in spring of the subsequent year, recoveries from storage were 79.8, 85.6 and 86.0% of DM; 84.1, 92.3 and 88.1 of energy; and 77.6, 91.5 and 92.2% of crude protein (CP). Ad libitum DM intakes were not significantly different (102.6, 99.7 and [Formula: see text] for the three treatments, respectively). Late-cut forages (both fresh and wilted) were significantly (P &lt; 0.05) higher in fiber fractions (lignin and acid detergent insoluble nitrogen) than the early-cut forages. Similar trends persisted among the silages at feeding time after 9 mo of storage. Differences in the chemical composition and digestibilities of nutrients for EFS and EWS were small and statistically not significant (P &gt; 0.05). When fed at maintenance level, the digestibility values for DM, energy and cellulose were significantly (P &lt; 0.05) higher for EWS than for LWS but not for EFS. However, when fed ad libitum in combination with corn silage (1:1 DM basis), there were no significant effects of either harvesting date or wilting vs. formic acid treatments on the digestibility of nutrients. Key words: Alfalfa, silages, digestibility, formic acid, maturity stage, wilted silage

Solubility and flow of calcium, magnesium and phosphorus in the digestive tract of sheep given maize or alfalfa silages

Four sheep, each fitted with a rumen cannula and a re-entrant cannula in the proximal duodenum and terminal ileum, were used for collection of rumen, duodenal and ileal digesta. Four normal sheep were used for collection of faeces. They were given maize silage, maize silage ensiled with urea, wilted alfalfa silage or formic acid-treated alfalfa silage. Although the solubility of the calcium (Ca) in the duodenal digesta was higher with sheep on maize silages than with those on alfalfa silages, sheep fed on maize silage showed negative apparent absorption (−32.7 and −16.5%) owing to the low concentration of Ca in whole-plant maize. The apparent absorption of magnesium (Mg) was 40.6–42.3% for maize silages and 24.2–26.8% for alfalfa silages. The differences between silages with respect to apparent absorption of phosphorus (P) were not significant and ranged between 1.5 and 10.9%. There were no appreciable differences in soluble proportions, flow and apparent absorption of Ca, Mg and P between the two maize silages or the two alfalfa silages. There was a net absorption of Ca and Mg and a net secretion of P in the stomach of animals on all silages.

FLOW AND SOLUBLE PROPORTIONS OF ZINC, MANGANESE, COPPER AND IRON IN THE GASTROINTESTINAL TRACT OF SHEEP FED CORN OR ALFALFA SILAGES

A set of four sheep, each fitted with a rumen cannula and a re-entrant cannula in the ascending duodenum and terminal ileum, were used for collection of rumen, duodenal and ileal digesta. A second set of four normal sheep was used for collection of feces and urine. The sheep were fed corn silage, urea-added corn silage, formic acid-treated alfalfa silage or wilted alfalfa silage in latin square design. Soluble proportions of manganese in rumen fluid, ileal digesta and feces were much lower on alfalfa silages than on corn silages although the soluble proportions in the duodenal digesta were not different. The soluble proportions of zinc, copper and iron were not as consistent as those of manganese. The apparent absorption of zinc was negative on alfalfa silages, and was associated with the lower soluble proportion of zinc in duodenal digesta and higher in the ileal digesta, as compared to corn silages. The apparent absorption of iron was much higher on corn silages than on alfalfa silages. Addition of urea to corn at ensiling resulted in an improvement of apparent absorption of copper. Key words: Trace elements, solubility, absorption, corn silage, alfalfa silage, sheep

DIGESTION OF CORN AND ALFALFA SILAGES IN THE STOMACH AND SMALL INTESTINE OF SHEEP PREPARED WITH TWO RE-ENTRANT CANNULAS

Four wethers, each fitted with a re-entrant cannula in the proximal duodenum and terminal ileum, were used to study digestion of corn and alfalfa silages. The four silages fed were (1) corn silage (2) corn silage with 0.6% urea (fresh weight basis) added at the time of ensiling (3) direct-cut alfalfa silage treated with formic acid (5 g/kg fresh alfalfa) and (4) wilted alfalfa silage. Urea additions to corn silage increased crude protein from 8.1 to 13.2% which resulted in an increase (P &lt; 0.05) in microbial yield from 1.99 to 3.23 g N/100 g organic matter (OM) apparently digested in the stomach. The apparent digestion of OM in the stomach was lower (P &lt; 0.05) with formic-acid-treated alfalfa silage (48.6%) compared to the wilted alfalfa silage (56.1%), but this difference had disappeared at the ileum. The preservation of alfalfa silage with formic acid compared to wilting resulted in a greater (P &lt; 0.05) flow from the stomach and digestion within the small intestine of non-ammonia nitrogen. This effect of formic acid on non-ammonia dynamics was unrelated to microbial yield.

Comparison of Alfalfa Hay and Alfalfa Silage Alone and with Supplements of Grain, Hay, or Corn Silage for Growing Dairy Calves

Summary It was again demonstrated that dairy heifers can be successfully reared to calving time on a ration using only 370lb. of whole milk, 400–500lb. of grain, and unlimited quantities of good alfalfa hay. Substituting a mixture of wilted alfalfa and corn silages for the hay in such a feeding schedule produced very low rates of gain and feed consumption. As a result, the final weight of heifers so fed was only 76% of normal. The performance of heifers fed the corn and alfalfa silages was below that of other heifers fed straight wilted alfalfa silage. Feeding wilted alfalfa silage plus a supplement of either hay (1 lb/cwt) or grain (2 lb/day) produced heifers that were only slightly smaller at 2 yr. of age than heifers reared on alfalfa hay. Heifers fed the silage ration consumed less dry matter than heifers fed hay. Reasons for the voluntary decrease in consumption of heifers fed silage are not apparent.

Vitamin D Content of Roughages

Very little vitamin D generally is considered to exist in the green growing plant. Ergosterol or some other provitamin is present and may be changed over to vitamin D when the plant is cut and exposed to the radiant energy of the sun, as in the sun curing of roughages. From this viewpoint it could be assumed that flue or barn-cured hay would have less vitamin D than sun-cured hay and that little or no vitamin D would be present in roughages cured in the dark or artificially dried with no sun exposure. However, this is not the case according to results obtained at this Station. Assays made on sun-cured and barn-cured hays show practically equal amounts of vitamin D in the two hays. Furthermore, appreciable amounts of vitamin D arc present in hays dried without exposure to the sun, as in a dehydrating machine or natural-drying in a dark place. A few trials at other stations have been reported showing that the nutritive and antirachi~ic values of barn-cured hay compare favorably with that of sun-cured hay for dairy animals, as based on such criteria as rate of growth, physical condition and analyses of certain bones from slaughtered animals. However, no vitamin D contents of the hays were given. Wylie et al. (8), in a trial with yearling heifers, compared the feeding value of barn-cured hay with that of sun-cured hay. The feeding periods extended through three successive winters, each trial being 150 days in length. Each animal received daily 2 lb. of grain, 10 lb. of corn silage and hay ad libitum. The heifers in both groups made normal growth with no marked difference in favor of either. Moore and Thomas (4) report the results of a feeding trial with dairy calves comparing the antiraehitic values of field-cured alfalfa hay, barndried alfalfa hay and wilted alfalfa silage. They used three groups of dairy calves, six in each group. The calves were first depleted of their body stores of vitamin D and then fed on the above roughages for a period of 6 months. From the results obtained, it was concluded that further fundamental work is necessary. The indications to date are that barn-dried hay and wilted silage will provide sufficient vitamin D for normal functions in growing calves when fed at the usual levels of roughage feeding, i.e., at the rate of 2 to 3 lb. of hay, or the equivalent, per 100 lb. of body weight. EXPERIMENTAL