Jong-Su Eun

To identify whether the supplement of anaerobic fungi isolates with cellulolytic activities accelerates the silage fermentation. Three fungal isolates with the highest cellulolytic activities among 45 strains of anaerobic fungal stock in our laboratory were selected and used as silage inoculants. The rice straw (RS) was ensiled for 10, 30, 60, 90 and 120 days with four treatments of anaerobic fungi derived from the control (no fungus), Piromyces M014 (isolated from the rumen of the Korean native goat), Orpinomyces R001 (isolated from the duodenum of Korean native cattle) and Neocallimastix M010 (isolated from the guts of termites), respectively. The silages inoculated with pure strains of fungi showed a higher fungal population (P < 0·05) when compared to the control silage. In situ ruminal DM disappearance of RS silage (RSS) was improved with fungal treatment. SEM observation showed live fungal cells inoculated in RS could survive during the ensiling process. Overall, this study...

Abstract Text: Two grazing experiments were performed to 1) investigate the effects of supplementing condensed tannins (CT)-containing pine bark (PB) powder on ADG, ruminal fermentation, and gut microbial diversity dynamics, and 2) to quantify the influence of different sources of tannins supplementations on ruminal fermentation and gut microbial diversity changes of goats grazing winter pea and ryegrass dominant forages. In Exp. 1, 20 Kiko cross male goats (Capra hircus; initial BW = 39.7 ± 2.55 kg) were randomly assigned to 2 experimental diets (alfalfa pellet vs. PB powder). Alfalfa pellet (no CT as a control) or PB (11% CT) was supplemented at 0.8% BW for targeted total DMI of 1.2% BW. The remainder DMI of each diet was obtained from grazing for 60 d. In Exp. 2, 12 Kiko cross goats were used to measure ADG, ruminal fermentation, and gut microbial population in the rumen of goats grazing bermudagrass. The animals were randomly assigned to 3 experimental diets: 1) no tannins (cont...

Abstract Text: This experiment was performed to test a hypothesis that quality of alfalfa hay (AH) would affect nutritive benefits of feeding high moisture corn (HMC) due to their associative effects on nutrient utilization efficiency. Eight multiparous lactating Holstein cows were used; 4 were surgically fitted with ruminal cannula. Days-in-milk averaged 184 ± 10.7 at the start of the experiment. The experiment was performed in a duplicate 4 × 4 Latin square design. Within each square, cows were randomly assigned to a sequence of 4 diets during each of the four 21-d periods (14 d of treatment adaptation and 7 d of data collection and sampling). A 2 × 2 factorial arrangement was used; fair quality AH (FAH; 39.6% NDF and 17.9% CP) or high quality AH (HAH; 33.6% NDF and 21.9% CP) was combined with steam-flaked corn (SFC) or HMC to form 4 treatments: FAH with SFC, FAH with HMC, HAH with SFC, and HAH with HMC. The AH was fed at 32% DM, whereas HMC was included at 17% DM. Quality of AH d...

A lactating dairy cow experiment was conducted to determine the influence of a ruminal buffer product contain-ing magnesium-exchanged zeolite on ruminal fermentation and lactational performance. The experimental TMR diet consisted of 38% alfalfa hay, 19% corn silage, 14% corn grain, and 30% concentrate mix on a DM basis, and it was fed ad libitum. Thirty primiparous and multiparous lactating Holstein cows (52 ± 23.0 DIM) were assigned to 1 of 3 dietary treatments with 10 cows in each treatment: control (TMR diet without ruminal buffer), TMR diet with 1.4% sodium bicarbonate (SBD), and TMR diet with 1.4% zeolite product (ZD). The experiment was a completely random-ized design performed over 12 wk. Intake of DM was similar (26.5 kg/d) across treatments. Milk yield was similar among the 3 treatments (40.7 kg/d on aver-age), and efficiency (4% FCM/DMI) was not affected by treatments. Milk fat concentration did not differ among treat-ments, whereas milk protein concen-tration tended to b...

A grazing study was conducted to determine if growth performance and carcass characteristics of beef steers would be affected by N fertilization on tall fescue (TF) pasture. Eighteen Angus crossbred steers (394 ± 5.5 kg of BW) were grazed on the following two treatments: TF without N fertilizer (TF–NF) and TF with N fertilizer (TF+NF). A total of 168 kg/ha N fertilizer was applied in three split applications of 56 kg/ha to the TF+NF. The treatments were arranged in a randomized complete block design with 3 pasture replicates and 3 steers per pasture. Replicated 0.47-ha paddocks were established during spring 2010 and were grazed with beef steers from May through September 2010 for total of 16 wk. Grazing was for 7 d per paddock on a 28-d rotation interval. After the completion of 16-wk grazing, ultrasound measurements were performed to assess carcass characteristics. Intake of DM averaged 7.51 kg/d throughout grazing, and it did not differ between treatments (P > 0.26). In respon...

A continuous-culture experiment was performed to investigate the effects of tall fescue (TF)-to-legume ratios (TF:legume = 75:25, 50:50, or 25:75 on a DM basis) of 3 different TF-legume mixed diets [TF-alfalfa (TF+AF), TF-birdsfoot trefoil (TF+BT), or TF-cicer milkvetch (TF+CM)] on in vitro fermentation characteristics. Nine dietary treatments were tested in a 3 (TF-legume ratio) × 3 (TF-legume mixed diet) split-plot design. Dietary treatments did not affect the concentrations of total VFA, acetate, and butyrate, whereas increasing legume proportion increased propionate concentration (P = 0.03). Regardless of TF-legume ratio, feeding TF+CM resulted in the greatest propionate concentration, whereas TF+AF and TF+BT maintained a similar concentration of propionate. The TF+AF combination resulted in a greater acetate-to-propionate ratio than TF+BT or TF+CM (P = 0.03). Decrease in ammonia-N concentration (P < 0.01) was noticed when legume proportion decreased. Ammonia-N concentration ...

A 2-yr study was conducted to evaluate the effects of finishing beef cattle grazed on tall fescue (TF) pastures without or with N fertilization on growth performance, ruminal fermentation, and carcass characteristics. In each grazing season, 18 Angus crossbred steers were arranged in a completely randomized design with repeated measures on the following 2 treatments: TF without N fertilizer (TF–NF) and TF with N fertilizer (TF+NF). Three replicated pastures with 3 steers per replicate were assigned to each treatment. A total of 168 kg/ha N fertilizer was applied in 3 split applications at 56 kg/ha each to the TF+NF in each grazing season. Steers rotationally grazed on 0.47-ha pasture for 7 d with a 28-d rotation interval for a total of 16 wk. Body weight data and pasture forage samples were collected every 4 wk, whereas ruminal fluid was collected at wk 4, 10, and 16. After the completion of 16-wk grazing, ultrasound measurement was performed to assess carcass characteristics. In re...

Feeding high-grain diets to finishing beef cattle results in high proportions of saturated fatty acids (SFA) in the beef, which is considered to confer negative impacts on human health. In contrast, pasture-finished cattle produce lower proportion of SFA, greater n-3 and less n-6 polyunsaturated fatty acids (PUFA), and higher conjugated linoleic acids (CLA) compared to high grain-finished beef (Noviandi et al. 2012). Increased n-3 PUFA, especially C18:3 n-3, can reduce the risk of heart disease, hypertension, inflammation, and mammary cancer, and lower cholesterol concentration in blood (De Deckere et al. 1998; Tapiero et al. 2002). Nitrogen fertilisation can increase biomass production and nitrogen (N) concentration of tall fescue (TF; Festuca arundinacea) (Berg and Sims 2000; Teuton et al. 2007), which positively affected beef cattle performance (Berg and Sims 1995). However, the metabolism of fatty acids (FA) in pasture-finished beef steers due to N fertilization on TF has not ye...

A continuous culture experiment was performed to investigate effects of tall fescue (TF)-legume mixed pasture forages [TF-alfalfa (TF+ALF), TF-birdsfoot trefoil (TF+BFT), or TF-cicer milkvetch (TF+CMV)] with 3 different composition ratios at 25:75, 50:50, or 75:25 on a DM basis on in vitro fermentation characteristics. Nine dietary treatments were tested in a completely randomized design with a 3 (TF-legume mixtures) × 3 (TF:legume ratios) factorial arrangement. Each culture fermentor was offered a total of 15 g DM/d in 4 equal portions at 0600, 1200, 1800, and 2400 h. Average daily culture pH ranged from 6.10 to 6.29 and was affected by TF-legume mixture and composition ratio (P < 0.01). Total VFA concentration averaged 51.4 mM and was not affected by treatments. While acetate concentration was similar across treatments, propionate concentration increased by the TF+CMV (P < 0.01). Decreasing legume proportion in the forage mixtures decreased propionate concentration (P = 0.03...

Teff (Erogrostis tef [Zucc.], Poaceae) is a warm-season annual grass and has attracted much interest among hay growers in the United States due to its rapid growth, palatability, and high quality and yield. The objective of this study was to assess growth performance and ruminal fermentation of growing beef steers and dairy heifers when fed teff hay-based diets. Twelve growing beef steers and 12 dairy heifers were used in a completely randomized design to test 2 dietary treatments: alfalfa hay-based TMR (AHT) and teff hay-based TMR (THT). In beef steer diets, the AHT contained 20.5% alfalfa hay and 43.0% corn silage, whereas the THT had 44.0% teff hay and 20.7% corn silage. In dairy heifer diets, the AHT contained 54.1% alfalfa hay and 24.8% corn silage, while the THT had 8.5% alfalfa hay, 42.0% teff hay, and 11.3% corn silage. All animals were placed in individual pens, and the experiment lasted 12 wk. Intake of DM increased by feeding the THT to beef steers and dairy heifers (P = ...

An exogenous proteolytic enzyme (EPE) has been previously found to increase in vitro NDF degradability of dried distillers grains with solubles (DDGS). To further investigate the effects of EPE, 48 Angus crossbred growing beef steers (292 ± 25.2 kg BW) were used to assess the growth performance when fed a DDGS-based TMR diet without or with an EPE supplementation in a completely randomized design. The growing TMR diet consisted of 13.6% alfalfa hay, 50.3% corn silage, 30.7% DDGS, and 5.4% feedlot supplement (DM basis). The EPE contained 38,622 U/g protease activity with negligible fibrolytic activities. The EPE was diluted with water and added at a rate of 0.52 g/kg DM TMR as it was mixing for the group of EPE treatment. Four animals were placed in each pen, and 6 pens allocated to each treatment. All steers were adapted to the TMR diet for a 2-week period before start of the trial. Feed was offered for ad libitum consumption once daily at 0800 h with free access to water. Feed inta...

A livestock study was conducted to evaluate the effects of pasture finishing vs. feedlot finishing beef steers on subcutaneous adipose tissue fatty acid (FA) composition. Twenty-seven Angus crossbred steers were arranged on the following 3 treatments: grazing on tall fescue without N fertilizer (TF–NF), grazing on tall fescue with N fertilizer (TF+NF), and feeding TMR on feedlot (FLT). A total of 168 kg/ha N fertilizer was applied in 3 split applications of 56 kg/ha to the TF+NF. The treatments were arranged in a randomized complete block design with 3 replicates and 3 steers per replicate. The pasture-finished steers grazed on replicated 0.47-ha paddocks from May through September 2010 for total of 16 wk. The steers on FLT were housed in 3 group pens with 3 animals per pen and fed a typical finishing diet containing 83% barley grain. Adipose tissue biopsies were obtained on wk 4, 12, and 16. There were no effects of time and treatment × time interaction on FA composition (P > 0....

Eight dual-flow continuous culture fermentors (700 mL) were used to assess effects of energy supplementation [no concentrate, 30% ground corn, or 30% dried distilled grains with solubles (DDGS)] with 4 pasture forages [tall fescue (TF) without N fertilizer (TF-NF), TF with N fertilizer (TF+NF), TF-alfalfa mixture, and TF-birdsfoot trefoil mixture (TF+BFT)] on in vitro ruminal fermentation and N utilization. Twelve dietary treatments were tested in a completely randomized design with a 3 (energy supplements) × 4 (pasture forages) factorial arrangement. Each culture fermentor was offered a total of 15 g DM/d. Forages were supplied in 4 equal portions at 0600, 1200, 1800, and 2400 h, while energy supplements were fed in 2 equal portions at 1200 and 2400 h. Three replicated runs lasted 10 d each, with the first 7 d allowed for microbial adaptation to the diets, and 3 d for sampling. Average daily culture pH was affected by energy supplementation (P < 0.05), but not by forage, ranging ...

Abstract Text: Ruminal fermentation characteristics were investigated with 36 Angus crossbred steers grazing 4 treatments: 1) tall fescue (TF) with no fertilizer (TF–NF), 2) TF with N fertilizer (TF+NF), 3) TF-alfalfa mixture (TFALF), and 4) TF-birdsfoot trefoil mixture (TFBFT). Treatments were tested in a randomized complete block design with 3 pasture replicates, 4 paddocks per pasture, and 3 steers per pasture. Replicated 0.47-ha paddocks were grazed with beef steers from May through September in 2013 for total of 16 wk. Steers grazed for 7 d per paddock on a 28-d rotation interval. Pasture forage samples were collected at 4-wk intervals throughout the experiment. Ruminal fluid samples were obtained from all steers using a Geishauser probe at wk 4, 8, 12, and 16 to measure pH and analyze VFA profiles and ammonia-N (NH3-N) concentration. Concentration of CP in pasture forages was greater (P < 0.01) in mixtures than grass monocultures at wk 4 (12.8 vs. 7.89%), but it was similar...

A lactation experiment was conducted to determine the influence of quebracho condensed tannin extract (CTE) on ruminal fermentation and lactational performance of dairy cows. The cows were fed a high forage (HF) or a low forage (LF) diet with a forage-to-concentrate ratio of 59:41 or 41:59 on a dry matter (DM) basis, respectively. Eight multiparous lactating Holstein cows (62 ± 8.8 d in milk) were used. The design of the experiment was a double 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments, and each period lasted 21 d (14 d of treatment adaptation and 7 d of data collection and sampling). Four dietary treatments were tested: HF without CTE, HF with CTE (HF+CTE), LF without CTE, and LF with CTE (LF+CTE). Commercial quebracho CTE was added to the HF+CTE and the LF+CTE at a rate of 3% of dietary DM. Intake of DM averaged 26.7 kg/d across treatments, and supplementing CTE decreased intakes of DM and nutrients regardless of forage level. Digestibilities of DM and nu...

Due to the increasing cost of soybean meal and concerns of excess N being excreted into the environment, new protein supplements have been developed. Two products that have shown potential in increasing N utilization efficiency are slow-release urea (SRU; Optigen; Alltech Inc., Nicholasville, KY) and ruminal-escape protein derived from yeast (YMP; DEMP; Alltech Inc.). The objective of this study was to assess the effects of feeding these 2 supplements in alfalfa hay-based [45.7% of forage dietary dry matter (DM)] dairy diets on nutrient utilization, feed efficiency, and lactational performance of dairy cows. Twelve multiparous dairy cows were used in a triple 4 × 4 Latin square design with one square consisting of ruminally cannulated cows. Treatments included (1) control, (2) SRU-supplemented total mixed ration (SRUT), (3) YMP-supplemented total mixed ration (YMPT), and (4) SRU- and YMP-supplemented total mixed ration (SYT). The control consisted only of a mixture of soybean meal a...

This experiment was conducted to determine the effects of corn silage hybrids and nonforage fiber sources (NFFS) in high forage diets formulated with high dietary proportions of alfalfa hay (AH) and corn silage (CS) on ruminal fermentation and productive performance by early lactating dairy cows. Eight multiparous Holstein cows (4 ruminally fistulated) averaging 36±6.2 d in milk were used in a duplicated 4 × 4 Latin square design experiment with a 2 × 2 factorial arrangement of treatments. Cows were fed 1 of 4 dietary treatments during each of the four 21-d replicates. Treatments were (1) conventional CS (CCS)-based diet without NFFS, (2) CCS-based diet with NFFS, (3) brown midrib CS (BMRCS)-based diet without NFFS, and (4) BMRCS-based diet with NFFS. Diets were isonitrogenous and isocaloric. Sources of NFFS consisted of ground soyhulls and pelleted beet pulp to replace a portion of AH and CS in the diets. In vitro 30-h neutral detergent fiber (NDF) degradability was greater for BMR...

A series of in vitro fermentation experiments was performed to assess the effects of 4 feed enzyme products (FE) that varied in enzymatic activities on the degradation of alfalfa hay and corn silage. The FE contained a range of endoglucanase, exoglucanase, xylanase, and protease activities, and a range of dose rates (DR) was used. The objective of the study was to identify effective formulations and optimum DR, and to establish if combining FE would further improve fiber degradation. For alfalfa hay, quadratic increases in gas production and degradation of dry matter (DM) and fiber were observed for all FE, with maximum responses at low to medium DR. For corn silage, none of the FE increased gas production or DM degradation, but all FE increased NDF degradation, with optimum DR in the low to medium range. The proteolytic enzyme papain improved fiber degradation of alfalfa hay and corn silage in a manner similar to that observed for polysaccharidase FE. Among the polysaccharidase FE,...

Two in vitro experiments were performed to identify promising exogenous fibrolytic enzyme products (EFE) and optimum dose rates (DR) for improving the degradation of alfalfa hay and corn silage. The relationship between enzymatic activity and fermentation responses was examined to identify optimum formulations. In experiment 1, 5 EFE containing mainly endoglucanase and xylanase activities, with different ratios between the 2 activities, were assessed at a DR of 0.7, 1.4, and 2.1 mg/g of DM forage. Milled alfalfa hay or corn silage was incubated in an in vitro batch culture with buffer, ruminal fluid, and EFE. Gas production (GP) was measured during 24 h of incubation, and degradabilities of DM and fiber were measured after terminating the incubation at 24 h. Two (E1 and E3) EFE substantially improved GP and degradation of alfalfa hay and corn silage fiber. The optimum DR of these EFE was 1.4 mg/g of DM for both forages with improvements in NDF degradability up to 20.6% for alfalfa h...

The effects of exogenous proteolytic enzyme (EPE) on intake, digestibility, ruminal fermentation, and lactational performance were determined using 8 lactating Holstein cows in a double 4 x4 Latin square experiment with a 2 x2 factorial arrangement of treatments. Diets based on barley silage and alfalfa hay as the forage sources were formulated to maintain different forage to concentrate ratios [60:40 vs. 34:66, dry matter (DM) basis]. Four dietary treatments were tested: high forage (HF) without EPE (HF-EPE), HF with EPE (HF+EPE), low forage (LF) without EPE (LF-EPE), and LF with EPE (LF+EPE). The EPE, which contained proteolytic activity but negligible fibrolytic activity, was added to the concentrate portion of the diets after pelleting at a rate of 1.25 mL/kg of DM. Adding EPE to the diet increased total tract digestibilities of DM, organic matter, N, acid detergent fiber, and neutral detergent fiber, with larger increases in digestibility observed for cows fed LF+EPE. Effects o...

Mechanical processing of whole crop barley before ensiling may be useful for improving nutrient use by dairy cattle. The objective of this study was to assess the effects of feeding mechanically processed barley silage as the main forage source on lactational performance. Twenty-four Holstein cows, 16 primiparous (187 +/- 52 days in milk) and 8 multiparous (87 +/- 69 days in milk) cows, were used in a completely randomized design with a 2-wk covariate period and a 6-wk treatment period. The 2 treatments were: 1) total mixed ration (TMR) containing regular barley silage (RBS-TMR), and 2) TMR containing mechanically processed barley silage (MPBS-TMR). Barley silage and alfalfa hay supplied 41 and 5% of the dietary dry matter (DM), respectively. Intake, body weight, and milk production were measured during the covariate and treatment periods. In addition, 2 multiparous cows were used for in situ measurements of the ruminal DM and fiber degradation kinetics of the barley silages and TMR...

This study evaluated the effects of dilution rate and forage-to-concentrate ratio on gas production by rumen microbes. Continuous cultures were used to monitor methane production at three liquid dilution rates (3.2, 6.3, or 12.5%/h) and three forage-to-concentrate ratios (70:30, 50:50, or 30:70). Filtered ruminal contents were allowed 6 d of adaptation to diets followed by 7 d of data collection. Forage consisted of pelleted alfalfa and the concentrate mix included ground corn, soybean meal, and a mineral and vitamin premix. The experiment was replicated in a split-plot design. Total volatile fatty acid production averaged 58.0 mmol/d and was not affected by treatment. Molar proportion of acetate increased with increasing forage-to-concentrate ratio. Molar proportion of propionate tended to decrease at dilution rate of 12.5%/h and increased with the medium and low forage-to-concentrate ratio. Culture pH tended to be greater at a dilution rate of 12.5%/h. Methane production that was ...

ABSTRACT A series of in vivo experiments was conducted for the effects of supplementing corn-based dried distillers grains with solubles (DDGS) to a barley ration for growing and finishing beef steers on growth performance, digestibility, ruminal fermentation and carcass characteristics. Forty-five predominantly British-based crossbred steers (initial body weight (BW)=257±16kg) were used in these trials. Steers were housed in groups of 5 in shaded pens, and they received one out of three treatment diets: control without DDGS (C), low inclusion level of DDGS (LD) and high inclusion level of DDGS (HD). The concentrate of the C diet consisted of only dry rolled barley, whereas the LD and the HD diets contained both dry rolled barley and DDGS. While the growing diet contained 105 and 175g DDGS/kg diet dry matter (DM) to the LD and HD diets, the finishing diet comprised 114 and 183g DDGS/kg diet DM to the LD and HD diets, respectively. In a completely randomized design, the growing and the finishing trials lasted for 84 and 112 d, respectively, and BW change, DM intake, average daily gain (ADG), gain to feed ratio (G:F) and carcass characteristics were measured. Right after completion of the performance trials, a digestibility trial was performed to test the C and HD diets used in the growing trial to assess digestibility and ruminal fermentation in a replicated 2×2 Latin square design using four beef cows.Initial and final BW did not differ among treatments in the growing and the finishing trials (P>0.55). However, growing steers fed the HD diet gained the largest BW followed by the LD and the C diets (P=0.05). Intake of DM decreased as more DDGS were included in the growing diets (P0.48), neutral detergent fiber (aNDF) digestibility tended (P=0.14) to increase with feeding the HD diet. Ruminal pH numerically increased with the HD diet, but it failed to have a significant effect (P=0.33). Supplementing DDGS in a barley ration to growing and finishing steers resulted in no adverse effects on performance, digestion, ruminal fermentation and carcass characteristics, although DM intake was reduced at relatively lower inclusion rates of DDGS compared with those typically used in other studies. The LD and HD diets improved ADG and G:F of growing steers, whereas both diets resulted in similar responses on ADG and G:F of finishing steers compared to the C diet. The positive responses of growing steers are likely due to increases in ruminal pH and aNDF digestion. With increasing availability and economic feasibility, DDGS can be effectively supplemented to barley-based beef diets up to 183g/kg diet DM.