Biomedical subjects

L Kung

Publications and source records attributed to L Kung.

At least 19 recordsLinked to original sources

PubMed2006

The effects of Lactobacillus buchneri 40788 and Pediococcus pentosaceus R1094 on the fermentation of corn silage.

The effect of inoculating whole-plant corn at the time of harvest with Lactobacillus buchneri 40788 (4 x 10(5) cfu/g of fresh forage) combined with Pediococcus pentosaceus R1094 (1 x 10(5) cfu/g) on the fermentation and aerobic stability of corn silage (37% dry matter) through 361 d of ensiling was investigated. Dry matter recovery was similar between treatments throughout the study except at one early time point (14 d), when treated silage had a lower recovery than untreated silage. The concentration of lactic acid was unaffected by inoculation but inoculated silages had greater concentrations of 1,2-propanediol and acetic acid from 56 to 361 d of storage. In general, inoculation decreased the concentration of water-soluble carbohydrates but increased the concentration of ethanol. The numbers of yeasts was lower in inoculated silage at 42, 56, 70, and 282 d of ensiling. However, inoculation did not consistently improve the aerobic stability of silage, suggesting that microbes other than yeasts may have been responsible for aerobic instability in this study. Even after prolonged storage (361 d), silage treated with L. buchneri 40788 and P. pentosaceus R1094 had normal silage fermentation characteristics.

Acetic Acid↗

PubMed2006

A meta-analysis of the effects of Lactobacillus buchneri on the fermentation and aerobic stability of corn and grass and small-grain silages.

The results of adding Lactobacillus buchneri to silages from 43 experiments in 23 sources reporting standard errors were summarized using meta-analysis. The effects of inoculation were summarized by type of crop (corn or grass and small grains) and the treatments were classified into the following categories: 1) untreated silage with nothing applied (LB0), 2) silage treated with L. buchneri at < or = 100,000 cfu/g of fresh forage (LB1), and 3) silage treated with L. buchneri at > 100,000 cfu/g (LB2). In both types of crops, inoculation with L. buchneri decreased concentrations of lactic acid, and this response was dose-dependent in corn but not in grass and small-grain silages. Treatment with L. buchneri markedly increased the concentrations of acetic acid in both crops in a dose-dependent manner. The numbers of yeasts were lower in silages treated with LB1 and further decreased in silages treated with LB2 compared with untreated silages. Untreated corn silage spoiled after 25 h of exposure to air but corn silage treated with LB1 did not spoil until 35 h, and this stability was further enhanced to 503 h with LB2. In grass and small-grain silages, yeasts were nearly undetectable; however, inoculation improved aerobic stability in a dose-dependent manner (206, 226, and 245 h for LB0, LB1, and LB2, respectively). The recovery of DM after ensiling was lower for LB2 (94.5%) when compared with LB0 (95.5%) in corn silage and was lower for both LB1 (94.8%) and LB2 (95.3%) when compared with LB0 (96.6%) in grass and small-grain silages.

Acetic Acid↗

PubMed2005

The effects of various antifungal additives on the fermentation and aerobic stability of corn silage.

In 2 consecutive years, whole plant corn was ensiled in laboratory silos to investigate the effects of various silage additives on fermentation, dry matter (DM) recovery and aerobic stability. In yr 1, chopped forage was treated with 1) no additive (untreated, U), 2) Lactobacillus buchneri 40788, 4 x 10(5) cfu/g of fresh forage (LLB4), 3) L. buchneri 11A44, 1 x 10(5) cfu/g (PLB), 4) Biomax 5 (Lactobacillus plantarum PA-28 and K-270), 1 x 10(5) cfu/g (B5), 5) Silo Guard II (sodium metabisulfite and amylase), 0.05% of fresh forage weight (SG), 6) a buffered propionic acid-based additive, 0.1% (Ki-112), 7), sodium benzoate, 0.1% of fresh weight (SB), or 8) potassium sorbate:EDTA (1:1), 0.1% of fresh weight (PSE). Silage treated with LLB4 had the highest concentration of acetic acid compared with other treatments, and yeasts were undetectable in LLB4 ( 210 h.

Acetic Acid↗

PubMed2004

The effects of buffered propionic acid-based additives alone or combined with microbial inoculation on the fermentation of high moisture corn and whole-crop barley.

Buffered propionic acid-based additives (BP) alone or in combination with a microbial inoculant containing lactic acid bacteria (MI) were mixed with ground, high moisture corn or whole-crop barley and ensiled in triplicate laboratory silos to investigate their effects on silage fermentation and aerobic stability. The inoculant and chemicals were applied separately for treatments that included both additives. The addition of MI alone had no effect on DM recovery, fermentation end products, or aerobic stability of high moisture corn. However, treatments with 0.1 and 0.2% BP (alone and the combination) had more than 10- and 100-fold fewer yeasts, respectively, and they also had greater concentrations of propionic acid than did untreated corn. Corn treated with only 0.1 (161 h) and 0.2% (218 h) BP tended to be more stable when exposed to air than untreated corn (122 h). Treatment with MI + 0.2% BP markedly improved the aerobic stability (>400 h) of high moisture corn. With whole-crop barley, the addition of MI alone, BP alone, and combinations of MI and BP prevented the production of butyric acid that was found in untreated silage (0.48%). All barley silages that had MI in their treatments underwent a more efficient fermentation than treatments without MI, as evident by a greater ratio of lactic:acetic acid and more DM recovery than in untreated silage. Increasing levels (0.1 to 0.2%) of BP added together with MI improved the aerobic stability of barley (190 and 429 h) over the addition of MI alone (50 h). These data show that buffered propionic acid-based products are compatible with microbial inoculants and, in some circumstances when used together, they can improve the fermentation and aerobic stability of silages.

Acetic Acid↗

PubMed2004

A comparison of processed conventional corn silage to unprocessed and processed brown midrib corn silage on intake, digestion, and milk production by dairy cows.

We studied the effects of mechanical processing and type of hybrid on the nutritive value of corn silage for lactating cows. Treatments were brown midrib (BMR) corn silage that was unprocessed (U-BMR), BMR corn silage that was processed (P-BMR), and a conventional corn silage that was processed (P-7511). All silages were harvested at a theoretical chop length of 19 mm. The chemical compositions of the silages were similar among treatments except that BMR silages were lower in lignin and higher in protein than P-7511. Brown midrib silages had greater 30-h in situ and in vitro NDF digestion than did P-7511, and processing had no effect on 30-h in situ and in vitro fiber digestion, but it increased in situ starch digestion after 3 and 12 h of incubation. Both processed silages had a smaller proportion of particles >1.91 cm and fewer whole corn kernels compared with unprocessed silage. Lactating cows were fed a total mixed ration (TMR) consisting of 42% of each silage type, 40% concentrate, 10% alfalfa silage, and 8% alfalfa hay (DM basis). Cows fed TMR containing P-BMR ate more DM and produced more milk than cows fed P-7511. At feeding, the TMR containing U-BMR had a larger proportion of particles >1.91 cm when compared with the TMR of cows fed processed silages, and after 24 h the difference was even greater, indicating that cows fed unprocessed corn silage sorted more. Cows fed TMR with P-7511 and P-BMR had greater total tract digestibility of organic matter, crude protein, and starch compared with cows fed U-BMR. In vivo digestibility of neutral detergent fiber was greatest for cows fed P-BMR when compared with the other treatments.

Animals↗

PubMed2003

Effects of 9,10 anthraquinone on ruminal fermentation, total-tract digestion, and blood metabolite concentrations in sheep.

The objective of this study was to evaluate the effects of adding 9,10 anthraquinone, a known inhibitor of methanogenesis and sulfate reduction, on blood metabolites, digestibility, and distribution of gas in sheep. In all experiments, we fed a complete pelleted diet that contained 17.5% crude protein and 24.5% acid detergent fiber. In an 8-wk study, feeding up to 66 ppm (dry matter basis) of 9,10 anthraquinone had no adverse effects on blood metabolites including indicators of normal enzyme function, mineral concentrations, and hematological measurements. Feeding 9,10 anthraquinone had no effect on average daily gain, although sheep fed a diet containing 66 ppm of 9,10 anthraquinone numerically gained the least weight. The ruminal molar proportions of acetic acid were decreased (P < 0.05) and the molar proportions of propionic acid were increased (P < 0.05) in sheep fed 1.5 and 66 ppm 9,10 anthraquinone when compared to those fed an unsupplemented diet. In a digestion trial, 9,10 anthraquinone (33 and 66 ppm) had no effect on the apparent digestion of nutrients in the total gastrointestinal tract. In a metabolism study, ruminal gasses were collected by rumenocentesis and analyzed for methane and hydrogen concentrations. Feeding 500 ppm of 9,10 anthraquinone to sheep resulted in a decrease (P < 0.07) in the concentration of methane, but an increase (P < 0.05) in hydrogen concentration of ruminal gas throughout the 19 d of feeding. There was no indication of ruminal adaptation throughout this time. These results are the first to show that 9,10 anthraquinone can partially inhibit in vivo rumen methanogenesis, which supports previous in vitro findings. In addition, at the concentrations used in this study, 9,10 anthraquinone was not toxic to ruminants.

Animals↗

PubMed2003

The effect of treating alfalfa with Lactobacillus buchneri 40788 on silage fermentation, aerobic stability, and nutritive value for lactating dairy cows.

Lactobacillus buchneri 40788 and enzymes (beta-glucanase, alpha-amylase, xylanase, and galactomannase) were applied to chopped alfalfa (39% DM) to study their effects on the fermentation and nutritive value of the silage. Alfalfa was treated with nothing, or L. buchneri 40788, for a final application rate of 1 x 10(5), 5 x 10(5), or 1 x 10(6) cfu/g of fresh forage and ensiled in laboratory silos for 2, 4, 8, and 56 d. Treatment with L. buchneri 40788 had few effects on the end products of fermentation through 8 d of ensiling. However, after 56 d of ensiling, treated silages had a higher pH (4.55 vs. 4.38) and higher concentrations of acetic acid (6.40 vs. 4.24%), propionic acid (0.18 vs. 0.06%), and ammonia-N (0.35 vs. 0.29%) when compared to untreated silage. Lactic acid was also numerically lower in treated (3.51%) than untreated (4.12%). Silages treated with the moderate and highest dose of L. buchneri 40788 also resulted in greater recoveries of DM than did untreated silage. Alfalfa (43% DM) was also untreated or treated with a commercial application of L. buchneri 40788 (4 x 10(5) cfu/g, a commercial dose) in farm-scale bag silo. Holstein cows were fed a diet comprised of 32% untreated or treated alfalfa silage, 11% corn silage, 5% chopped alfalfa hay, and 52% of concentrate (DMB) for a 6-wk treatment period. Dry matter intake and milk composition were unaffected by treatment, but cows fed silage treated with L. buchneri 40788 produced 0.8 kg more milk than did cows fed untreated silage. Treated silage had a higher concentration of acetic acid (5.67 vs. 3.35%) but lower lactic acid (3.50 vs. 4.39%) than untreated silage. When exposed to air, the total mixed ration containing treated alfalfa silage remained stable for 100 h, whereas the ration containing untreated silage spoiled after 68 h. Treating alfalfa silage with L. buchneri 40788 increased the concentration of acetic acid, and when the silage was combined into a total mixed ration and fed to lactating cows, it improved the aerobic stability of the ration and increased milk production.

Acetic Acid↗

PubMed2003

Effects of cutting height and maturity on the nutritive value of corn silage for lactating cows.

We studied the effect of increasing the cutting height of whole-plant corn at the time of harvest from 12.7 (NC) to 45.7 (HC) cm on yield and nutritive value of silage for dairy cows. Three leafy corn silage hybrids were harvested at NC and HC at about 34% dry matter (E) and 41% DM (L) and ensiled in laboratory silos. Increasing the height of cutting lowered yields of harvested DM/ha. In addition, the concentrations of DM and starch were higher but the concentrations of lactic acid, crude protein, neutral detergent fiber (NDF), and acid detergent fiber were lower in HC than in NC. The concentration of acid detergent lignin was also lower in HC, but only in corn harvested at E. In vitro digestion (30 h) of NDF was greater in HC (50.7%) than NC (48.3%). Calculated yield of milk per tonne of forage DM was greater for HC than for NC at E but not at L. In a lactation experiment, increasing the height of cutting of another leafy corn silage hybrid, TMF29400, in general also resulted in similar changes in nutrient composition as just described. When fed to lactating dairy cows, HC corn silage resulted in tendencies for greater NDF digestion in the total tract, higher milk production and improved feed efficiency, but there were no differences in 3.5% fat corrected milk between treatments. Results of this study suggest that increasing the cutting height of whole plant corn at harvest can improve the nutritive value of corn silage for lactating dairy cows.

Animal Nutritional Physiological Phenomena↗

PubMed2002

The effect of Lactobacillus buchneri 40788 on the fermentation and aerobic stability of high moisture corn in laboratory silos.

The production of antifungal compounds during fermentation could be a useful mechanism to improve the aerobic stability of fermented feeds when they are exposed to air. High moisture corn (26% moisture) was ground and inoculated with various amounts of Lactobacillus buchneri 40788, a heterolactic acid bacteria, and ensiled in laboratory silos. Inoculation with L. buchneri 40788 from 1 x 10(5) to 1 x 10(6) cfu/g of corn had minor effects on the end products of fermentation during the early stage of ensiling (< or = 14 d). However, after 49, 92, and 166 d of ensiling, increasing the application rate of L. buchneri 40788 applied to corn increased the concentration of acetic acid when compared to untreated corn. Addition of L. buchneri 40788 had few other effects on the end products of fermentation. Dry matter recovery and aerobic stability were measured after 92 and 166 d of ensiling. At these times, dry matter recovery was not different among treatments, and numbers of yeasts and molds tended to decrease as the application rate of L. buchneri 40788 increased. Aerobic stability (number of h prior to a 2 degrees C rise in temperature after exposure to air) was markedly improved by the addition > or = 5 x 10(5) cfu/g of L. buchneri 40788. Combining L. buchneri 40788 with L. plantarum did not impart better aerobic stability than when L. buchneri 40788 was applied alone to corn. Addition of L. buchneri 40788 did not affect the rate of fermentation in high moisture corn, but after prolonged storage higher application rates increased production of acetic acid and markedly improved aerobic stability.

Acetic Acid↗

PubMed2002

The effect of treating whole-plant barley with Lactobacillus buchneri 40788 on silage fermentation, aerobic stability, and nutritive value for dairy cows.

Chopped barley forage was ensiled untreated or treated with several doses (1 x 10(5) to 1 x 10(6) cfu/g of fresh forage) of Lactobacillus buchneri 40788 in laboratory silos and untreated or treated (4 x 10(5) cfu/g) in a farm silo. Silage from the farm silos was fed to lactating cows. In the laboratory silo, the effects of inoculation on fermentation and aerobic stability were also compared to silage treated with a commercial inoculant and a buffered propionic acid additive. Inoculation with L. buchneri 40788 decreased the final concentrations of lactic acid but increased concentrations of acetic acid and ethanol in silage from laboratory and farm silos. Silages stored in laboratory silos did not heat after exposure to air for 7 d and were then mixed with alfalfa silage and a concentrate to form total mixed rations (TMR) that were further exposed to air. The TMR containing silages treated with L. buchneri 40788 or a buffered propionic-acid-based additive took longer to heat and spoil than the TMR containing untreated silage or silagetreated with the commercial inoculant. Silage stored in a farm silo and treated with L. buchneri 40788 had fewer yeasts and molds than did untreated silage. Aerobic stability was greater in treated silage alone and in a TMR containing treated silage. Dry matter intake (18.6 kg/d), milk production (25.7 kg/d), and milk composition did not differ between cows fed a TMR containinguntreated or treated silage. These findings show that L. buchneri can improve the aerobic stability of barley silage in laboratory and farm silos and that feeding treated silage had no negative effect on intake or performance.

Acetic Acid↗

PubMed2002

The effect of delayed ensiling and application of a propionic acid-based additive on the fermentation of barley silage.

Prolonged exposure to air can adversely affect the silage fermentation process. To investigate a possible method to overcome this problem, we determined if a buffered propionic acid-based additive, applied to chopped, whole-plant barley exposed to air before ensiling, would affect the subsequent fermentation. Wilted forage was chopped and treated with nothing, or with 0.1% (wt/wt wet forage) of a buffered propionic acid-based additive and ensiled immediately in quadruplicate 20-L laboratory silos. Portions of the chopped forage, untreated and treated, were left in loose piles in a barn for 24 h before ensiling. Another portion of the untreated silage exposed to air for 24 h was also treated with 0.1% of the additive just before ensiling. Prolonged exposure to air before ensiling increased the numbers of yeasts on forages by more than 1,000-fold. The concentrations of water-soluble carbohydrates decreased by more than 50%; the ammonia-N concentrations increased 40%, and pH increased by more than 1 unit as a result of exposure to air. These changes were less in forage that was treated with the additive at chopping. After 60 d, silages of forages that were exposed to air before ensiling had a higher pH, higher concentrations of ammonia-N and butyric acid, and lower concentrations of lactic and acetic acids than silages of forage that had been ensiled immediately after harvest. In situ DM digestibility was lowest in untreated silages that had been exposed to air before ensiling. In contrast, treatment with the additive, applied before or after exposure to air, prevented the reduction in in vitro digestion.

Acetic Acid↗

PubMed2002

The effect of fibrolytic enzymes sprayed onto forages and fed in a total mixed ratio to lactating dairy cows.

We investigated the effect of spraying different combinations of fibrolytic enzymes onto forages on their nutritive value for lactating cows. Holstein cows were fed a TMR consisting of 30% corn silage, 15% alfalfa hay, and 55% concentrate (dry matter basis). During a 12-wk treatment period, the forages were treated with no enzymes (control), cellulase D and sultanas B, or cellulase D and xylanase C. Enzymes were diluted in water and sprayed onto the forages while mixing. Both combinations of enzymes supplied similar amounts of fibrolytic activity based on classical enzyme assays conducted at 50 degrees C. Cows fed forages treated with cellulase D and xylanase B tended to produce more 3.5% FCM (+2.5 kg/d) than did cows fed the untreated forages. Dry matter intake, milk production, milk fat, and milk protein were unaffected by treatment. In vitro production of gas from forages treated with enzymes was greater than from untreated forage, but 96-h volatile fatty acid production was not different among treatments. With an alternative enzyme assay based on the depolymerization of dyed substrate at 40 degrees C, activity of xylanase C was greatest at a pH of 6.5 but was substantially reduced as the pH of the assay was decreased. In contrast, xylanase B showed highest activity at pH 5 and enzyme activity was twice that of xylanase B at pH 5.5 and 6. Overall, the results of this study provide more evidence that fibrolytic enzymes can be used to improve milk production in lactating cows.

Animal Feed↗

PubMed2001

Tissue distribution of calcineurin and its sensitivity to inhibition by cyclosporine.

The immunosuppressive activity of cyclosporine is mediated by inhibiting calcineurin phosphatase. However, calcineurin is widely distributed in other tissues. We examined the degree of calcineurin inhibition by cyclosporine in various tissues. In vitro, the cyclosporine concentration inhibiting 50% (IC50) of calcineurin was to approximately 10 ng/mL in human and mouse leukocytes suspensions. In vitro and in vivo IC50s of cyclosporine in homogenates of mouse kidney, heart, liver, testis, and spleen were also comparable (9-48 ng/mL). The maximum calcineurin inhibition by cyclosporine varied, from 83 to 95% of calcineurin activity in spleen, kidney, liver, and testis to 60% in heart and only 10% in brain. Maximum calcineurin inhibition was increased by the addition of cyclophilin A, indicating that cyclophilin concentrations were limiting in some tissues, at least in this assay. Western analysis of mouse tissues showed significantly less cyclophilin in heart than other tissues. cyclosporine concentrations per weight of tissue protein were highest in kidney and liver and lowest in brain and testis after oral dosing, with intermediate levels in spleen, heart, and whole blood. Thus each cyclosporine dose produces rapid and wide-spread inhibition of calcineurin in tissues, with differences in total susceptibility of each tissue.

Animals↗

PubMed2001

The effect of Lactobacillus buchneri and other additives on the fermentation and aerobic stability of barley silage.

Whole-plant barley (39.4% dry matter) was treated with various chemical and biological additives to assess their effects on silage fermentation and aerobic stability. Treatments were untreated forage, forage treated with several amounts of Lactobacillus buchneri and enzymes (L. buchneri at 1 x 10(5), 5 x 10(5), and 1 x 10(6) cfu/g of fresh forage), forage treated with an inoculant containing (Lactobacillus plantarum, Pediococcus pentosaceus, Propionibacterium freudenreichii, and enzymes), or forage treated with a buffered propionic acid-based additive (0.2% of fresh weight). Sixty-nine d after ensiling, silages treated with L. buchneri and enzymes had lower pH, but had higher concentrations of acetic and propionic acids and higher concentrations of ethanol when compared with untreated silage. Silage treated with the multistrain inoculant containing L. plantarum had lower pH and higher concentrations of lactic acid, but lower concentrations of ammonia-N, neutral detergent fiber, and acid detergent fiber than did untreated silage. The addition of the buffered propionic acid additive resulted in silage with higher concentrations of lactic and acetic acid compared with untreated silage. Numbers of yeasts in all silages were low at silo opening (less than 3.0 log cfu/g) and were numerically the lowest in silages treated with L. buchneri but only treatment with the intermediate and high level of L. buchneri improved the aerobic stability of silage. Because of the altered fermentation pattern, inoculation with L. buchneri, when applied at equal to or more than 5 x 10(5) cfu/g, and enzymes improved the aerobic stability of barley silage.

Acetic Acid↗

PubMed2001

The effect of a dry or liquid application of Lactobacillus plantarum MTD1 on the fermentation of alfalfa silage.

Alfalfa was wilted to 30 and 54% dry matter and was untreated or treated with Lactobacillus plantarum MTD1 applied either as a liquid or dry inoculant to determine whether form of inoculation affected silage fermentation. In silages with 30% dry matter, both forms of inoculation resulted in silages with more lactic acid and a lower pH than in untreated silage after 2 d of ensiling. In addition, both forms of inoculation resulted in silages with lower concentrations of acetic acid between 8 and 45 d of ensiling than in untreated silage. The ammonia-N content was also lower in silages that had been treated with both forms of inoculation during the early and intermediate stages of ensiling, but not after 45 d of ensiling. In silages containing 54% dry matter, dry and liquid inoculation produced a more rapid decrease in pH from d 4 to 14 when compared with untreated silage, but the effect was greater when the inoculant was applied in water. In contrast to findings from 30% silages, the inoculated silages with 54% dry matter had lower concentrations of ammonia-N than untreated silage from d 8 to 45, and both forms of inoculation were equally effective. The results of this study agree with previous research that shows that microbial inoculation can improve the fermentation of alfalfa silage. However, this report shows that a microbial inoculant was more effective when applied in a liquid- rather than a dry-form to alfalfa with a high DM content.

Acetic Acid↗

PubMed2000

Immunophilins may limit calcineurin inhibition by cyclosporine and tacrolimus at high drug concentrations.

BACKGROUND: The immunosuppressive drugs cyclosporine (CsA) and tacrolimus (FK506 or FK) are qualitatively similar but differ in molar potency. Both drugs sterically inhibit the phosphatase activity of calcineurin (CN) but differ in molar potency. In our study we explored whether differential inhibition of CN explained the differences in molar potency of FK versus CsA. METHODS: We compared their effects on NFATC2 dephosphorylation using Western analysis, interferon-gamma production using ELISA, and CN phosphatase activity using the CN assay in human peripheral blood leukocytes (PBL) and mouse spleen cell suspension. RESULTS: The FK concentration inhibiting 50% (IC50) of all three activities was approximately 0.2 microg/ml in human PBL, versus 5-20 microg/ml for CsA. Although inhibition of interferon-gamma secretion and NFATC2 dephosphorylation was complete, inhibition of CN phosphatase activity was incomplete with both drugs at saturation, particularly with FK. Inhibition of CN phosphatase activity was incomplete whether FK treatment was in vivo in mouse or in vitro in various human and mouse tissues, especially brain. Exogenous FKBP12 or CyPA increased CN phosphatase inhibition, suggesting that incomplete inhibition of CN phosphatase activity reflected limiting amounts of active immunophilin. CONCLUSIONS: These data contradict the prevailing assumption that immunophilins are abundant and not limiting for inhibition of CN by CsA or FK. Further, the observation that FK and CsA completely inhibit immune function without completely inhibiting CN suggests that the inhibition of immune function is not mediated by general CN inhibition but by inhibition of a subset of CN which is critical for lymphocyte activation.

Animals↗

PubMed2000

The effect of treating forages with fibrolytic enzymes on its nutritive value and lactation performance of dairy cows.

Forages (corn silage and alfalfa hay) were sprayed with liquid enzymes prior to combining with a concentrate to form a total mixed ration (50% forage:50% concentrate, dry matter basis) and fed to lactating cows. In the first year, treatments were 1) no enzymes, 2) an enzyme complex containing 3500 carboxymethyl cellulase (CMCase) and 16,000 xylanase units per kilogram of forage dry matter, or 3) an enzyme complex containing 8800 CMCase units and 40,000 xylanase units. In the second year, the treatments were 1) no enzymes, 2) an enzyme complex as in yr 1 containing 3700 CMCase and 14,000 xylanase units, or 3) an enzyme complex using an alternative cellulase and containing 3600 CMCase and 11,000 xylanase units. In the first year, cows fed diet 2 tended to produce more milk (39.5 kg/d) than those fed diet 1 (37.0 kg/d) or those fed diet 3 (36.2 kg/d). The high level of enzyme treatment in diet 3 decreased the output of milk protein and fat compared to the low level of enzyme treatment. In the second year, cows fed diet 3 produced more milk (35.4 kg/d) than did those fed diet 1 (32.9 kg/d) and numerically more than those fed diet 2 (33.6 kg/d). Milk fat and protein were similar among treatments but numerically lower for cows fed enzyme-treated forages. Dry matter intake (kg/d) was similar among treatments in both years. Spraying certain doses and combinations of enzymes directly onto forages prior to feeding can improve milk yields but enzyme sources and dose levels are of critical importance.

Animal Nutritional Physiological Phenomena↗

PubMed2000

The effect of Lactobacillus buchneri, Lactobacillus plantarum, or a chemical preservative on the fermentation and aerobic stability of corn silage.

Several microorganisms and one chemical preservative were tested for their effects on the fermentation and aerobic stability of corn silage. Whole-plant corn (one-half milk line, 31.3% dry matter) was ensiled in quadruplicate 20-L laboratory silos untreated or after the following treatments: Lactobacillus buchneri at 1 x 10(5) and 1 x 10(6) cfu/g of fresh forage; two different strains of L. plantarum, each at 1 x 10(6) cfu/g; and a buffered propionic acid-based product at 0.1% of fresh forage weight. After 100 d of ensiling, silage treated with L. buchneri (1 x 10(6) cfu/g) had a lower concentration of lactic acid compared with the untreated silage, but was similar to other treated silages. The silage treated with the high (1 x 10(6) cfu/g), but not the moderate rate (1 x 10(5) cfu/g) of L. buchneri also had a greater concentration of acetic acid (3.60%) and less yeasts (2.01 log cfu/g) when compared with other treatments (average of 1.88% acetic acid and 5.85 log cfu of yeasts/g). Silages treated with L. plantarums, the moderate rate of L. buchneri, and the chemical preservative took longer to heat than untreated silage when exposed to air, but improvements were numerically small (6.3 to 10.5 h). In contrast, silage treated with the high rate of L. buchneri never heated throughout a 900-h period of monitoring. Inoculating corn silage with 1 x 10(6) cfu/g of L. buchneri resulted in a more heterolactic fermentation and dramatically improved the aerobic stability of corn silage.

Acetic Acid↗