Sam Churl Kim

Effect of applying inoculants with heterolactic or homolactic and heterolactic bacteria on the fermentation and quality of corn silage

This study examined the effect of applying different bacterial inoculants on the fermentation and quality of corn silage. Corn plants were harvested at 35% DM, chopped, and ensiled in 20-L mini silos after application of (1) deionized water (CON) or inoculants containing (2) 1 × 10(5) cfu/g of Pediococcus pentosaceus 12455 and Propionibacteria freudenreichii (B2); (3) 4 × 10(5) cfu/g of Lactobacillus buchneri 40788 (BUC); or (4) 1 × 10(5) cfu/g of Pediococcus pentosaceus 12455 and 4 × 10(5) cfu/g of L. buchneri 40788 (B500). Four replicates of each treatment were weighed into polyethylene bags within 20-L mini silos. Silos were stored for 575 d at ambient temperature (25°C) in a covered barn. After silos were opened, aerobic stability, chemical composition, and yeast and mold counts were determined. The DNA in treated and untreated silages was extracted using lysozyme/sodium dodecyl sulfate lysis and phenol/chloroform and used as a template for a conventional PCR with primers designed on the 16S rRNA gene to detect the presence of L. buchneri in all silage samples. Acetic acid concentration was greater in B2 silages versus others (6.46 vs. 4.23% DM). Silages treated with BUC and B500 had lower pH and propionic acid concentration and greater lactic acid concentration than others. The B500 silage had the greatest lactic:acetic acid ratio (1.54 vs. 0.41), and only treatment with BUC reduced DM losses (5.0 vs. 14.3%). Yeast and mold counts were less than the threshold (10(5)) typically associated with silage spoilage and did not differ among treatments. Consequently, all silages were very stable (>250 h). Aerobic stability was not improved by any inoculant but was lower in B500 silages versus others (276 vs. 386 h). The conventional PCR confirmed the presence of similar populations of L. buchneri in all silages. This may have contributed to the prolonged aerobic stability of all silages.

Effect of fibrolytic enzyme application to low- and high-concentrate diets on the performance of lactating dairy cattle

The objective of this study was to examine the effect of applying a fibrolytic enzyme preparation to diets with high (48% of diet dry matter, DM) or low (33% of diet DM) proportions of concentrate on production performance of lactating dairy cows. Sixty lactating Holstein cows (589 kg ± 20; 22 ± 3 d in milk) were stratified according to milk production and parity and randomly assigned to 4 treatments with a 2 × 2 factorial arrangement. Dietary treatments included the following: 1) low-concentrate diet (LC); 2) LC plus enzyme (LCE); 3) high-concentrate diet (HC); and 4) HC plus enzyme (HCE). The enzyme was sprayed at a rate of 3.4 mg of enzyme/g of DM on the total mixed ration daily and the trial lasted for 63 d. A second experiment with a 4 × 4 Latin square design used 4 ruminally fistulated cows to measure treatment effects on ruminal fermentation and in situ ruminal dry matter degradation during four 18-d periods. Enzyme application did not affect dry matter intake (DMI; 23.9 vs. 22.3 kg/d) or milk production (32.8 vs. 34.2 kg/d) but decreased estimated CH(4) production, increased total volatile fatty acid concentration (114.5 vs. 125.7 mM), apparent total tract digestibility of DM (69.8 vs. 72.6%), crude protein (CP; 69.2 vs. 73.3%), acid detergent fiber (50.4 vs. 54.8%), neutral detergent fiber (53.7 vs. 55.4%), and the efficiency of milk production (1.44 vs. 1.60 kg of milk/kg of DMI). Feeding more concentrates increased DMI (21.5 vs. 24.8 kg/d), milk yield (32.2 vs. 34.7 kg/d), milk protein yield (0.89 vs. 0.99 kg/d), and DM (69.9 vs. 72.6%), but decreased ruminal pH (6.31 vs. 6.06). Compared with cows fed HC, those fed LCE had lower DMI (20.8 vs. 25.7 kg/d) and CP intake (3.9 vs. 4.8 kg/d), greater ruminal pH (6.36 vs. 6.10), and similar milk yield (33.2 ± 1.1 kg/d). Consequently, the efficiency of milk production was greater in cows fed LCE than those fed HC (1.69 vs. 1.42 kg of milk/kg of DMI). This fibrolytic enzyme increased the digestibility of DM, CP, neutral detergent fiber, and acid detergent fiber and the efficiency of milk production by dairy cows. Enzyme application to the low-concentrate diet resulted in as much milk production as that from cows fed the untreated high-concentrate diet.

Effect of applying molasses or inoculants containing homofermentative or heterofermentative bacteria at two rates on the fermentation and aerobic stability of corn silage

This study determined how the fermentation and aerobic stability of corn silage are affected by treatment with molasses or 2 dual-purpose inoculants applied at or above the recommended rate. Corn forage (DeKalb 69-70) was harvested at 39% dry matter (DM) and ensiled after treatment with no additives (control, CON), molasses (MOL), Buchneri 500 inoculant, or Pioneer 11C33 inoculant. Molasses was applied at 3% of forage DM. Buchneri 500 was applied at the recommended rate of 8 mg/kg fresh forage to supply 1 x 10(5) cfu/g of Pediococcus pentosaceus 12455 and 4 x 10(5) cfu/g of Lactobacillus buchneri 40788 (BB) or at twice the recommended rate (DBB). Pioneer 11C33 inoculant was applied at the recommended rate of 1.1 mg/kg fresh forage to supply 1 x 10(5) cfu/g of a mixture of Lactobacillus plantarum, L. buchneri, and Enteroccocus faecium (PN) or at twice the recommended rate (DPN). Each treatment was applied in quadruplicate and the treated forages were ensiled within 20-L mini silos for 135 d at 18 to 35 degrees C. Molasses-treated silages had greater ash and starch concentrations than CON silages and greater lactate and ethanol concentrations than other silages. Like CON silages, MOL silages had high yeast counts (>10(5) cfu/g); consequently, they deteriorated within 30 h as shown by temperature increase. Inoculant-treated silages had lower lactate to acetate ratios than CON or MOL silages largely because they had greater acetate concentrations. Consequently, all inoculant-treated silages had fewer yeasts (<10(5) cfu/g) and were more stable (>30 h) than CON and MOL silages. When applied at recommended rates, PN and BB had similar effects on silage chemical composition, fermentation, fungal counts, and aerobic stability, except for a lower lactate concentration in PN silages. Concentrations of VFA, and NH(3)-N, pH, and extent of aerobic stability were similar for PN, DPN, BB, and DBB silages. However, lactate concentration was greater in DPN than in PN. In conclusion, MOL application increased ethanol and lactate concentration and did not improve aerobic stability. Both dual-purpose inoculants made the fermentation more heterolactic and thereby improved the aerobic stability of corn silage. Doubling the rate of application of either inoculant did not further improve fermentation or aerobic stability.

Effects of an esterase-producing inoculant on fermentation, aerobic stability, and neutral detergent fiber digestibility of corn silage

This experiment evaluated effects of an inoculant containing esterase-producing bacteria on fermentation, aerobic stability, in situ dry matter digestibility (DMD), and neutral detergent fiber (NDF) digestibility (NDFD) of corn silage. Two corn hybrids grown on adjacent fields [Croplan Genetics 851RR2 (CS1) and Vigoro 61R36 (CS2)] were harvested at approximately 39% dry matter. Each forage was conserved in quadruplicate in 20-L mini silos with or without application of an inoculant at a level to achieve 1.0 x 10(4) cfu/g of Lactobacillus casei and 1.0 x 10(5) cfu/g of Lactobacillus buchneri. After 110 d of ensiling, silos were opened and silages were analyzed for chemical composition, fermentation indices, microbial counts, and aerobic stability. In situ DMD, 24-h and 48-h DMD, and NDFD were measured by incubating ground (6-mm) samples in triplicate in each of 2 lactating, fistulated dairy cows fed a corn silage-based diet. Inoculation decreased concentrations of total fermentation acids and lactate, as well as lactate to acetate ratio, and increased propionate concentration compared with the uninoculated control in CS1 but not CS2. Inoculation tended to decrease yeast counts of CS1 but increased yeast counts and tended to increase the mold counts of CS2. Consequently, inoculation improved the aerobic stability of CS1 by 57.3 h (98%) but decreased that of CS2 by 20.5 h (20%). Inoculation also increased the potentially degradable fraction of CS1 and the total degradable fraction, 24-h and 48-h DMD, and 48-h NDFD of CS2. Inoculation of CS1 modified the fermentation, improved the aerobic stability, and increased the potentially degradable DM fraction. Inoculation of CS2 did not affect fermentation, but decreased the aerobic stability and increased the total degradable DM fraction, 24-h and 48-h DMD, and 48-h NDFD.

Effects of feeding crude glycerin on performance and ruminal kinetics of lactating Holstein cows fed corn silage- or cottonseed hull-based, low-fiber diets

The objective was to determine whether crude glycerin could partially replace concentrate ingredients in corn silage- or cottonseed hull-based diets formulated to support minimal milk fat production without reducing milk production. Multiparous, lactating Holstein cows (n=24; 116 ± 13d in milk) were assigned to dietary treatments arranged in a 2 × 3 factorial design; namely, 2 dietary roughage sources (cottonseed hulls or corn silage) and 3 dietary concentrations of glycerin [0, 5, or 10% on a dry matter (DM) basis]. Four different cows received each dietary treatment in each of 3 periods such that each diet was evaluated using 12 cows. Crude glycerin, produced using soybean oil, contained 12% water, 5% oil, 6.8% sodium chloride, and 0.4% methanol. Glycerin partially replaced ground corn, corn gluten feed, and citrus pulp. Diets of minimum fiber concentrations were fed to lactating dairy cows and resulted in low concentrations of milk fat (averaging 3.12% for cows fed diets without glycerin). The effects of glycerin on cow performance and ruminal measurements were the same for both dietary roughage sources with the exception of feed efficiency. Replacing concentrate with crude glycerin at 5% of dietary DM increased DM intake without increasing milk yield. Concentration and yield of milk fat were reduced when glycerin was fed at 10% of dietary DM. This was accompanied by a 30% reduction in apparent total-tract digestion of dietary neutral detergent fiber. Crude glycerin affected the microbial population in the rumen as evidenced by increased molar proportions of propionic, butyric, and valeric acids and decreased molar proportions of acetic acid. Efficiency of N utilization was improved as evidenced by lower concentrations of blood urea nitrogen and ruminal ammonia-N. Cows fed cottonseed hull-based diets consumed 5.3 kg/d more DM but produced only 1.7 kg/d more milk, resulting in reduced efficiency. Increased production of ruminal microbial protein, molar proportion of propionic acid, and passage of ruminal fluid resulted from feeding the cottonseed hull- versus corn silage-based diets, although apparent digestibilities of DM and neutral detergent fiber were reduced. Replacing 5 and 10% of concentrate ingredients with crude glycerin improved efficiency of 4% fat-corrected milk production when corn silage-based diets were fed but decreased it when cottonseed hull-based diets were fed.

Effect of applying bacterial inoculants containing different types of bacteria to corn silage on the performance of dairy cattle

This study examined the effect of applying different bacterial inoculants to corn silage at the time of ensiling on the performance of lactating dairy cows. Corn plants were harvested at 35% dry matter (DM), chopped, and ensiled in 2.4-m-wide bags after application of (1) no inoculant (CON); (2) Biotal Plus II (B2) containing Pediococcus pentosaceus and Propionibacteria freudenreichii; (3) Buchneri 40788 (BUC) containing Lactobacillus buchneri; or (4) Buchneri 500 (B500) containing Pediococcus pentosaceus and L. buchneri. All inoculants were supplied by Lallemand Animal Nutrition (Milwaukee, WI). Each of the 4 silages was included in separate total mixed rations consisting of 44% corn silage, 50% concentrate, and 6% alfalfa hay (DM basis). Fifty-two lactating Holstein cows were stratified according to milk production and parity and randomly assigned at 22 d in milk to the 4 dietary treatments. Cows were fed for ad libitum consumption and milked twice daily for 49 d. Dietary treatment did not affect intakes (kg/d) of DM (20.0), crude protein (CP; 3.7), neutral detergent fiber (NDF; 5.7), or acid detergent fiber (ADF; 3.6), or digestibility (%) of DM (73.9) or CP (72.4). However, NDF digestibility was lower in cows fed B2 compared with those fed other diets (45.3 vs. 53.0%). Consequently, cows fed B2 had lower digestible NDF intake (kg/d) than those fed other diets (2.5 vs. 3.0 kg/d). Dietary treatment did not affect milk yield (32.3 kg/d), efficiency of milk production (1.61), concentrations of milk fat (3.18%) and protein (2.79%), or yields of milk fat (1.03 kg/d) and protein (1.26 kg/d). Inoculant application to corn silage did not affect milk yield or feed intake of cows.

Stay-green ranking and maturity of corn hybrids: 1. Effects on dry matter yield, nutritional value, fermentation characteristics, and aerobic stability of silage hybrids in Florida.

This study determined effects of maturity, stay-green (SG) ranking, and hybrid source on dry matter (DM) yield, nutritive value, fermentation, and aerobic stability of corn hybrids. One high stay-green (HSG) hybrid and one average stay-green (ASG) hybrid with similar relative maturity (117 d) from each of 2 seed companies (Croplan Genetics, St. Paul, MN; Pioneer Hi-Bred International, Des Moines, IA) were grown on 1-× 6-m plots at random locations within each of 4 blocks. The hybrids were harvested at 25, 32, and 37% DM from each plot and separated into thirds for botanical fractionation and analysis, whole-plant chemical analysis, and ensiling. Chopped, whole plants were ensiled (8 kg) in quadruplicate in 20-L mini-silos for 107 d. A split-plot design was used for the study. Yields of whole-plant and digestible DM and concentrations of starch and DM increased with maturity, whereas concentrations of crude protein, water-soluble carbohydrates, and neutral detergent fiber decreased. High SG hybrids had greater DM yield than ASG hybrids when harvested at 25 and 37%, but not 32% DM. Unlike those from Croplan Genetics, the Pioneer HSG hybrid had greater ear and whole-plant DM concentration than their ASG hybrids. Stover moisture and CP concentration were greater among HSG versus ASG hybrids, particularly among Croplan Genetics hybrids. Croplan Genetics HSG hybrids had greater neutral and acid detergent fiber concentrations and lower in vitro DM digestibility in the unensiled whole-plant, the stover, and the silage than their ASG hybrids, whereas contrasting trends were evident for Pioneer hybrids. Silage fermentation indices were largely unaffected by hybrid SG ranking, maturity, or source. Yeast counts increased with maturity and exceeded 10(5) cfu/g; therefore, all silages deteriorated with 26 h, irrespective of treatment. Among the hybrids examined, the optimal maturity for optimizing DM yield and nutritive value of the ASG and HSG hybrids was 37% DM. Stay-green ranking had maturity-dependent effects on the yield of hybrids but had varying effects on nutritional value depending on the source of the hybrid.

Anticoccidial effect of supplemental dietary Galla Rhois against infection with Eimeria tenella in chickens

The anticoccidial effects of Galla Rhois (GR) powder, which contains a major tannin-derived component of 52.7%, were evaluated in chickens following oral infection with Eimeria tenella. One-day-old chickens were assigned to five groups (control, unsupplemented, GR 0.5% supplemented [GRS 0.5%], GRS 1.0% [GRS 1.0%] and salinomycin supplemented [SS]). The chickens were fed a standard diet supplemented or not supplemented with GR or salinomycin for 10 days prior to infection. The birds received the supplemented diets continuously until 10 days post infection. The effects of GR on a E. tenella infection were evaluated by several parameters, including body weight gain, feed intake, oocyst excretion, bloody diarrhoea, and lesion scores. Infected chickens on the GRS and SS diets had a relatively moderate body weight loss (reduction ratio < 15%) and improved feed conversion. GRS and SS chickens produced significantly fewer faecal oocysts (P<0.05) and showed milder bloody diarrhoea compared with the E. tenella-infected control group. Furthermore, the lesion scores of both the GRS 0.5% and GRS 1.0% groups were significantly lower than the scores of the unsupplemented group on day 5 post infection. The lesion scores for the GR groups were similar to the scores for the SS group. In conclusion, this study suggests that GR appears to be as efficacious as salinomycin against E. tenella infection. GR supplementation leads to a reduction in infected chickens, although infected chickens are still affected compared with the uninfected control group. GR-based diets may be beneficial in preventing or treating coccidial infections in poultry.

Methanogenic archaea diversity in Hanwoo (Bos taurus coreanae) rumen fluid, rectal dung, and barn floor manure using a culture-independent method based on mcrA gene sequences.

The diversity of methanogenic archaea associated with Korean Hanwoo cattle was analyzed using mcrA gene sequences from samples of rumen fluid (RF), rectal dung (RD), and barn floor manure (BFM). The predominant species were Methanobrevibacter ruminantium in RF and BFM(63.6% and 62.4%, respectively) and Methanocorpusculum labreanum in RD (53.2%).

Effect of treatment with a mixture of bacteria and fibrolytic enzymes on the quality and safety of corn silage infested with different levels of rust

This project aimed to determine if a dual-purpose bacterial inoculant could mitigate potential adverse effects of increasing levels of rust infestation on the quality, aerobic stability, and safety of corn silage. Corn plants with no rust infestation (NR), or medium (all leaves on the lower half of the plant affected, MR), or high (all leaves affected, HR) levels of southern rust infestation were harvested at random locations on a field, chopped, and ensiled without (control, CON) or with a dual-purpose inoculant applied at a rate that supplied 1×10(5) cfu/g of Pediococcus pentosaceus 12455 and 4×10(5) cfu/g of Lactobacillus buchneri 40788. Each treatment was prepared in quadruplicate in 20-L mini silos and ensiled for 97 d. As the level of rust infestation increased, the concentrations of dry matter (DM) and neutral detergent fiber increased, whereas DM digestibility decreased by up to 16%. Control HR silages also had lower 24-h neutral detergent fiber digestibility (NDFD; 36.2% of DM) than CON MR (39.8%) or NR silages (38.1%). Inoculation increased the NDFD of NR (43.4%) and MR silages (45.7%) but not HR silages (33.0%). Concentrations of lactate and volatile fatty acids decreased with increasing rust infestation in CON silages, but this trend was absent in inoculated silages. In HR silages, inoculation increased aerobic stability by 75% (77.3 vs. 44 h), and prevented production of aflatoxin (5.2 vs. 0 mg/kg). The concentration of aflatoxin in uninoculated HR silages exceeded action levels stipulated by the US Food and Drug Administration. In conclusion, increasing rust infestation was associated with reductions in the nutritive value and fermentation of corn silage. Inoculation reduced adverse effects of rust infestation on the fermentation, increased 24-h NDFD of NR and MR silages, and decreased aerobic spoilage and aflatoxin production in HR silages.