• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.7
• /
• pp.929-939
• /
• 2011

The effects of micronization on in situ and in vitro nutrient disappearances of wheat, barley and corn were investigated in a series of experiments. In Experiment 1, chemical composition and in situ dry matter disappearance (DMD) of six varieties of wheat were determined. In addition, an in vitro study was completed using ground micronized and unmicronized wheat (var. Kansas). In Experiment 2, three varieties of wheat (Kansas, Sceptre and Laura) and in Experiment 3, three cereal grains (wheat, barley and corn) were either micronized for 1 min to attain internal kernel temperatures of 90-100$^{\circ}C$ or not (controls), and DM, protein and starch disappearances were estimated. In Experiment 2, an in vitro study was also completed using ground micronized and unmicronized wheat (var. Kansas). Wheat samples varied with respect to crude protein (10.0-21.2%), starch (61.6-73.9%), NDF (8.5-11.8%), volume weight (753-842 g/L) and kernel hardness (0.0-32.0). Rate (p = 0.003) and extent (p = 0.001) of in situ DMD differed among wheat varieties. Correlations between in situ kinetics, and chemical and physical properties of wheat varieties showed that protein content was negatively correlated with the rate of disappearance ($r^2$ = -0.77). Micronization of all grains markedly reduced (p = 0.001) the rate and extent of DM, and protein disappearances as compared to control samples. Micronization increased (p<0.05) the digestion of starch in wheat. However, release of ammonia into the incubation medium was markedly reduced (p<0.05), suggesting that micronization increased the resistance of protein to microbial digestion. Disappearances of DM, protein and starch differed (p = 0.001) among cereal grains with wheat>barley>corn. Micronization reduced the rate of DM disappearance (p = 0.011) and slowly degradable protein fractions (p = 0.03), however, increased (p = 0.004) slowly degradable starch fractions of all three cereals. Examination of in situ samples by scanning electron microscopy confirmed that microbial colonization focused on starch granules in micronized grains, and that the protein matrix exhibited resistance to microbial colonization. These results suggest that micronization may be used to increase the ruminal escape value of protein in cereal grains, but may lead to increased starch digestion if grains are finely ground.

• Animal Bioscience
• /
• v.36 no.5
• /
• pp.720-730
• /
• 2023

Objective: This study investigated the effects of corn silage as a source of microbial inoculant containing antifungal and carboxylesterase-producing bacteria on fermentation, aerobic stability, and nutrient digestibility of fermented total mixed ration (FTMR) with different energy levels. Methods: Corn silage was used as a bacterial source by ensiling for 72 d with an inoculant mixture of Lactobacillus brevis 5M2 and L. buchneri 6M1 at a 1:1 ratio. The corn silage without or with inoculant (CON vs MIX) was mixed with the other ingredients to formulate for low and high energy diets (LOW vs HIGH) for Hanwoo steers. All diets were ensiled into 20 L mini silo (5 kg) for 40 d in quadruplicate. Results: The MIX diets had lower (p<0.05) acid detergent fiber with higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber compared to the CON diets. In terms of fermentation characteristics, the MIX diets had higher (p<0.05) acetate than the CON diets. The MIX diets had extended (p<0.05) lactic acid bacteria growth at 4 to 7 d of aerobic exposure and showed lower (p<0.05) yeast growth at 7 d of aerobic exposure than the CON diets. In terms of rumen fermentation, the MIX diets had higher (p<0.05) total fermentable fraction and total volatile fatty acid, with lower (p<0.05) pH than those of CON diets. The interaction (p = 0.036) between inoculant and diet level was only found in the immediately fermentable fraction, which inoculant was only effective on LOW diets. Conclusion: Application of corn silage with inoculant on FTMR presented an antifungal effect by inhibiting yeast at aerobic exposure and a carboxylesterase effect by improving nutrient digestibility. It also indicated that fermented feedstuffs could be used as microbial source for FTMR. Generally, the interaction between inoculant and diet level had less effect on this FTMR study.

• Korean Journal of Agricultural Science
• /
• v.23 no.2
• /
• pp.188-205
• /
• 1996

This study was conducted to examine the effects of dietary energy and protein sources on the rumen microbial population of sheep. The results obtained were summarized as the follows; 1. Ruminal pH was highest in sheep fed the diet rapidly degraded in the rumen(F-F) as a energy (barley plus beet pulp) and protein source (rapeseed meal), and lowest in the diet (F-S) of rapidly degradable energy source plus slowly degradable protein source (corn gluten meal + cotton seed meal) without affecting by postfeeding time. 2. Ruminal ammonia concentration was higher in corn (slowly degradable) for energy source and rapeseed meal (rapidly degradable) for protein source (S-F) than others, and abruptly increased at 1 hr after feeding regardless of treatments. 3. Concentration of ruminal total volatile fatty acid, acetate and propionate were highest in F-S and peaked at 1 hr after feeding firstly and formed second peak at 9hrs, respectively. 4. Digestibilities of the proximates and ADF were not affected by treatment but NDF was highest in F- F. 5. Nitrogen retention was highest in S-F and lowest in F-F and F-S. 6. Digestibility and metabolizability of energy, contents of OCP, TDN, DE and ME were not affected by treatment.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.3
• /
• pp.487-494
• /
• 1992

This experiment was conducted to study the effect of addition of Lucerne juice (LJ) obtained by mechanical extraction of freshly harvested crop on the nutritive value of rice straw silage. Rice straw (RS) was ensiled with intact, NaOH or $NH_3$ treated LJ at 3:7 ratio on fresh weight basis (LJ RS, LJ NaOH RS and LJ $NH_3$ RS, respectively). Each alkali was mixed with fresh juice at a level of 4% of rice straw dry matter just before ensiling. Rice straw ensiled with water was prepared as the control (W RS). In the digestion trial, goats were allocated in a $4{\times}4$ Latin-square design and fed the diet containing three parts of RS silage and one part of wheat bran (DM basis). For the goats receiving the control silage, urea was supplemented at feeding time so as to adjust the nitrogen intake except for goats on LJ $NH_3$ RS silage. Crude protein content of RS silage was increased from 5.2 to 9.1% (DM basis) by the addition of intact LJ and to about 24% by $NH_3$ treated LJ. The control W RS silage contained only trace amount of lactic acid and was dominated by acetic and butyric acid. The addition of intact LJ reduced butyric acid content and $NH_3-N/TN$ of the silage whereas the addition of alkalized LJ increased those values and shifted to a butyrate type fermentation. Nutrient digestibilities and nitrogen balance of goats were almost the same when they were fed W RS and LJ RS silage indicating the addition of intact LJ did not improve the nutritive value. The addition of alkalized LJ significantly increased the fiber digestibilities of RS silage and $NH_3$ treatment was more effective than NaOH treatment. Postprandial ruminal $NH_3-N$ and blood urea nitrogen (BUN) concentrations were decreased by feeding LJ NaOH RS silage suggesting ruminal protein synthesis was enhanced along with the increase of energy supply for supply for rumen microbes by the alkali treatment. The advantageous fiber digestibilities of LJ $NH_3$ RS silage compared with those of LJ NaOH RS silage might be attributable to a sufficient nitrogen supply for microbial fiber digestion in the rumen.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.3
• /
• pp.365-371
• /
• 2016

This study was aimed to evaluate the stability of conjugated linoleic acids (CLAs) by nano-encapsulation against in vitro ruminal biohydrogenation by microbial enzymatic conversion. CLAs (free fatty acid form of CLA [CLA-FFA], nano-encapsulated CLA-FFA, triglyceride form of CLA [CLA-TG], and nano-encapsulated CLA-TG) were used in the in vitro fermentation experiments. When Butyrivibrio fibrisolvens (B. fibrisolvens) was incubated with CLA-FFAs, the concentrations of cis-9, trans-11 CLA and vaccenic acid (VA) slightly was decreased and increased by nano-encapsulation, respectively. When B. fibrisolvens was incubated with CLA-TG, the concentrations of cis-9, trans-11 CLA and VA decreased, but these were increased when B. fibrisolvens was incubated with nano-encapsulated CLA-TG. The nano-encapsulation was more effective against the in vitro biohydrogenation activity of B.fibrisolvens incubated with CLA-FFA than with CLA-TG. In the in vitro ruminal incubation test, the total gas production and concentration of total volatile fatty acids incubated with nano-encapsulated CLA-FFA and CLA-TG were increased significantly after 24 h incubation (p<0.05). Nano-encapsulated CLA-FFA might, thus, improve the ruminal fermentation characteristics without adverse effects on the incubation process. In addition, nano-encapsulated CLA-FFA increased the population of Fibrobacter succinogenes and decreased the population of B. fibrisolvens population. These results indicate that nano-encapsulation could be applied to enhance CLA levels in ruminants by increasing the stability of CLA without causing adverse effects on ruminal fermentation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.2
• /
• pp.211-218
• /
• 2016

This study evaluated the effect of Candida norvegensis (C. norvegensis) viable yeast culture on in vitro ruminal fermentation of oat straw. Ruminal fluid was mixed with buffer solution (1:2) and anaerobically incubated with or without yeast at $39^{\circ}C$ for 0, 4, 8, 16, and 24 h. A fully randomized design was used. There was a decrease in lactic acid (quadratic, p = 0.01), pH, (quadratic, p = 0.02), and yeasts counts (linear, p<0.01) across fermentation times. However, in vitro dry matter disappearance (IVDMD) and ammonia-N increased across fermentation times (quadratic; p<0.01 and p<0.02, respectively). Addition of yeast cells caused a decrease in pH values compared over all fermentation times (p<0.01), and lactic acid decreased at 12 h (p = 0.05). Meanwhile, yeast counts increased (p = 0.01) at 12 h. C. norvegensis increased ammonia-N at 4, 8, 12, and 24 h (p<0.01), and IVDMD of oat straw increased at 8, 12, and 24 h (p<0.01) of fermentation. Yeast cells increased acetate (p<0.01), propionate (p<0.03), and butyrate (p<0.03) at 8 h, while valeriate and isovaleriate increased at 8, 12, and 24 h (p<0.01). The yeast did not affect cellulolytic bacteria (p = 0.05), but cellulolytic fungi increased at 4 and 8 h (p<0.01), whereas production of methane decreased (p<0.01) at 8 h. It is concluded that addition of C. norvegensis to in vitro oat straw fermentation increased ruminal fermentation parameters as well as microbial growth with reduction of methane production. Additionally, yeast inoculum also improved IVDMD.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.7
• /
• pp.962-970
• /
• 2012

This study aimed to investigate the effects of ruminal infusion of garlic oil (GO) on fermentation dynamics, fatty acid (FA) profile, and abundance of bacteria involved in biohydrogenation in the rumen. Six wethers fitted with ruminal fistula were assigned to two groups for cross-over design with a 14-d interval. Each 30-d experimental period consisted of a 27-d adaptation and a 3-d sample collection. Goats were fed a basal diet without (control) or with GO ruminal infusion (0.8 g/d). Ruminal contents collected before (0 h) and at 2, 4, 6, 8, and 10 h after morning feeding were used for fermentation analysis, and 0 h samples were further used for FA determination and DNA extraction. Garlic oil had no influence on dry matter intakes of concentrate and hay. During ruminal fermentation, GO had no effects on total VFA concentration and individual VFA molar proportions, whereas GO increased the concentrations of ammonia nitrogen and microbial crude protein (p<0.05). Compared with control, GO group took a longer time for total VFA concentration and propionate molar proportion to reach their respective maxima after morning feeding. The ratio of acetate to propionate in control reduced sharply after morning feeding, whereas it remained relatively stable in GO group. Fatty acid analysis showed that GO reduced saturated FA proportion (p<0.05), while increasing the proportions of C18, t11-18:1 (TVA), c9,t11-conjugated linoleic acid (c9,t11-CLA), t10,c12-CLA, and polyunsaturated FA (p<0.05). The values of TVA/(c9,t11-CLA+TVA) and C18:0/(TVA+C18:0) were reduced by GO (p<0.05). Real-time PCR showed that GO tended to reduce Butyrivibrio proteoclasticus abundance (p = 0.058), whereas GO had no effect on total abundance of the Butyrivibrio group bacteria. A low correlation was found between B. proteoclasticus abundance and C18:0/(TVA+C18:0) (p = 0.910). The changes of fermentation over time suggested a role of GO in delaying the fermentation process and maintaining a relatively modest change of ruminal environment. The inhibitory effects of GO on the final step of biohydrogenation may be related to its antibacterial activity against B. proteoclasticus and other unknown bacteria involved.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.34 no.3
• /
• pp.193-201
• /
• 2014

This study was conducted to examine the effects of defaunation (removal of live protozoa) on fermentation characteristics, degradation of ryegrass hay and $CH_4$ (methane) production by rumen microbes when incubated with plant oils (SO, sunflower oil and LO, linseed oil) in vitro. Sodium lauryl sulfate (0.000375 g/ml) as a defaunation reagent was added into the culture solution and incubated anaerobically up to 24 h at $39^{\circ}C$. pH from defaunation was increased for all treatments from 6 h incubation times (p<0.01-0.001) compared with those from fauantion. Concentration of ammonia-N from defaunation is higher than that from faunation at 3 h (p<0.001), 12 h (p<0.05) and 24 h (p<0.001) incubation times. Defaunation decreased (p<0.01-0.001) total volatile fatty acid concentration at all incubation times. Molar proportions of $C_2$ (acetate, p<0.05-0.001) and butyrate (p<0.01-0.001) were also decreased by defaunation at all incubation times. Molar proportion of $C_3$ (propionate), however, was increased by defaunation at all incubation times (p<0.001). Thus the rate of $C_2$ to $C_3$ was decreased by defaunation at all incubation times (p<0.001). Defaunation decreased ED (effective degradability) of dry matter (p<0.001) and ED of neutral detergent fiber (p<0.001) of ryegrass hay. Defaunation decreased total gas, $CH_4$ production, $CH_4$ % in total gas and $CH_4/CO_2$ at all incubation times (p<0.001). Oil supplementation decreased total gas (p<0.05-0.001), $CH_4$ production (p<0.001) and $CH_4$ % in total gas (p<0.001) compared with control at all incubation times. The result of this study showed that defaunation combined with oil supplementation may cause an alteration of microbial communities and further medicate the fermentation pattern, resulting in both reduction of degradation of ryegrass hay and $CH_4$ production. No difference, however, was observed in all the examinations between SO and LO.

• Animal Bioscience
• /
• v.34 no.12
• /
• pp.1940-1950
• /
• 2021

Objective: The objective of this study was to explore the effects of maize straw treated with calcium oxide (CaO) and various moisture, on the composition and molecular structure of the fiber, and gas production by fermentation in an in vitro rumen environment. Methods: The experiment used 4×3 Factorial treatment. Maize straws were treated with 4 concentrations of CaO (0%, 3%, 5%, and 7% of dry straw weight) and 3 moisture contents (40%, 50%, and 60%). Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray fluorescence spectroscopy were employed to measure the surface texture, secondary molecular structure of carbohydrate, and calcium (Ca) content of the maize straw, respectively. The correlation of secondary molecular structures and fiber components of maize straw were analyzed by CORR procedure of SAS 9.2. In vitro rumen fermentation was performed for 6, 12, 24, 48, and 72 h to measure gas production. Results: Overall, the moisture factor had no obvious effect on the experimental results. Neutral detergent fiber (NDF), acid detergent fiber, acid detergent lignin, hemicellulose and cellulose contents decreased (p<0.05) with increasing concentrations of CaO treatment. Surface and secondary molecular structure of maize straw were affected by various CaO and moisture treatments. NDF had positive correlation (p<0.01) with Cell-H (H, height), Cell-A (A, area), CHO-2-H. Hemicellulose had positive correlation (p<0.01) with Lignin-H, Lignin-A, Cell-H, Cell-A. Ca content of maize straw increased as the concentration of CaO was increased (p<0.01). Gas production was highest in the group treated with 7% CaO. Conclusion: CaO can adhere to the surface of the maize straw, and then improve the digestibility of the maize straw in ruminants by modifying the structure of lignocellulose and facilitating the maize straw for microbial degradation.

• Journal of Animal Science and Technology
• /
• v.48 no.4
• /
• pp.513-520
• /
• 2006

A series of four in vitro experiments were conducted to evaluate condensed molasses solubles (CMS) as a source of nitrogen for ruminal microbes. In experiment 1, as compared with urea, the value of CMS as a nitrogen source was examined. In experiment 2, to determine the time needed for maximal response of microbial synthesis, the treatments were incubated for increasing times (from 6 h to 16 h). Because a sediment that was assumed to cause nitrogen loss was found after incubation in experiments 1 and 2, it was decided to avoid formation of sediment using sugar instead of molasses or a shorter time incubation (experiments 3 and 4). Furthermore, in experiment 4, because the extent to which ammonia nitrogen is released from CMS and urea before 6 h of incubation was uncertain, it was decided to examine the peaks of concentrations of ammonia nitrogen released from CMS and urea by sampling after 2 h incubation. There was no significant difference in the concentration of microbial-N between molasses/CMS and molasses/ urea treatments in experiment 1, although there were greater decreases in ammonia concentration with the molasses/CMS treatment. The microbial protein synthesis was increased progressively until 10 h for both treatments (experiment 2). Although ingredients that were completely soluble (sucrose, urea) were used in experiment 3, the sediment was still evident suggesting that the sediment was largely of microbial not feed origin. Ammonia release from CMS was much faster than from urea during 2 h incubation. In conclusion, the results of the present studies suggest that the feed value of CMS as a source of nitrogen for ruminal bacteria was similar to that of urea when it was estimated in vitro.