• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.699-707
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• 1992

Three goats were fed with $^{15}N$-labelled rice straw to study the characteristics of digestion, assimilation, metabolism and excretion of C and N compounds from rice straw. It was shown that the amount of $^{15}N$ assimilated into the bodies of the two slaughtered goats accounted for 38.5 and 23.6% of the total amount of $^{15}N$ ingestion in the experimental diet by each goat. The $^{15}N$ excreted via the feces and urine for the three goats accounted for 34.8, 33.2 and 33.9% of the total amount of $^{15}N$ ingested in the feed of the 3 goats. The recoveries of $^{15}N$ from the two slaughtered goats were 73.3 and 57.5%, with the corresponding rates of $^{15}N$ loss 26.7 and 42.5% respectively. The amino acids digestibilities were 68.7 and 54.0%, while the digestibilities of carbohydrates were 74.8 and 67.7% respectively for goats 1 and 3.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.4
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• pp.561-567
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• 1993

Twenty Korean native bulls averaging 181 kg body weight were fed a fixed amount (1.5% of live weight) of concentrate and free choice roughage cubes which had four ratios of rice straw and orchard grass hay; 100:0, 85:15, 70:30 and 55:45 on a weight basis. Five bulls were assigned to each treatment and fed for 98 days in a confinement house. Nutrient digestibility and available energy content of mixed rations (40% concentrate and 60% roughage cubes) was determined in a digestion trial with twelve wethers. In vitro dry matter digestibility (IVDMD) and in situ dry matter disappearance of the roughage cubes were also determined. The ratio of grass hay to rice straw did not influence dry matter intake. Significant improvements in body weight gains and feed/gain ratios were obtained as grass hay levels increased. Average daily gain and feed/gain for each treatment was 0.83, 0.88, 0.98 and 0.99 kg; 7.63m 7.59, 6.83 and 6.41, respectively. Digestibility of the nutrients was improved with increasing levels of grass hay in the cubes. The IVDMD of roughage samples having a ritio of 100:0, 85:15, 70:30 and 55:45 between rice straw and orchard grass hay were 31.0, 37.1, 41.8 and 43.4%, respectively. Grass hay improved the IVDMD of rice straw diets in a linear manner up to 30%. In situ dry matter disappearance rate was also increased as the level of orchard grass hay increased.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.487-494
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• 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
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• v.11 no.6
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• pp.692-696
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• 1998

An experiment was conducted with eight growing sheep (average initial weight 20.6 kg and average final weight 23.7 kg) in a $4{\times}4$ Latin square design to study the effect of type of forage supplementation to a basal diet of rice straw (ad libitum) and cassava (Manihot esculanta, approximately 9 g of dry matter $(DM).kg^{-0.75}{\cdot}day^{-1}$) on voluntary intake, digestion, rumen microbial protein synthesis and daily weight gain. Forages used were Leucaena (L, Leucaena leucocephala), Gliricidia (G, Gliricidia maculata) and Tithonia (T, Tithonia diversifolia, wild sunflower) at a DM supplementation level of approximately $13g.kg^{-0.75}.day^{-1}$. Organic matter intake was 40.4, 55.5, 55.0 and $54.9g{\cdot}kg.^{-0.75}{\cdot}day^{-1}$ for control (C, ad libitum straw and cassava), L, G and T. respectively, significantly lower for C than for the supplemented diets. Intake of supplementary forage had also a significantly positive effect on voluntary rice straw intake. All forage supplemented diets showed a significantly higher whole diet organic matter digestion than C ($488g{\cdot}kg^{-1}$), while T ($557g{\cdot}kg^{-1}$) differed significantly from L ($516g{\cdot}kg^{-1}$) but not from G ($526g{\cdot}kg^{-1}$). Daily weight gain was -1.7, 5.2, 5.4 and $4.7g{\cdot}kg^{-0.75}$, for C, L, G and T. respectively, significantly lower for C than for the forage-supplemented diets. Efficiency of microbial protein synthesis estimated from urinary excretion of purine derivatives was lower for C (3.8 g microbial N. (kg digestible organic matter intake $(DOMI))^{-1}$ than for the forage supplemented diets (11.3, 9.0 and 9.4 g microbial $N.(kg\;DOMI)^{-1}$ for L, G and T. respectively).

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.11-20
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• 2015

In the present work, a basic study on the in-situ biogenic methane generation from low grade coal bed was conducted. Lignite from Indonesia was used as a sample feedstock. A series of BMP (Biochemical Methane Potential) tests were carried out under the different experimental conditions. Although nutrients and anaerobic digester sludge were added to the coal, the produced amount of methane was limited. Both temperature control and particle size reduction showed little effect on the increase of methane potential. When rice straw was added to lignite as an external carbon source, methane yield of 94.4~110.4 mL/g VS was obtained after 60 days of BMP test. The calorific value of lignite after BMP test decreased (4.5~12.1 %) as increasing the content of rice straw (12.5~50 wt % of lignite), implying that anaerobic digestion of rice straw led to partial degradation of lignite. Therefore, rice straw could be used as an external carbon source for the start-up of in-situ biogas generation from low grade coal bed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.35-43
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• 2017

This study was to research the relationships between rice straw degradation and changes of fibrolytic bacteria population during the in vitro rumen fermentation. Dry matter(DM) digestion of rice straw and population of fibrolytic bacteria were measured at the 0. 4, 8, 12 and 48 hours during the incubation. The populations of F. succinogenes. R. albus and R. flavefaciens were defined as log copy number of 16S rDNA by technical method of Quantitative real-time PCR. Total population of F. succinogenes, R. flavefaciens and R. albus was sum of bactera attached on rice straw and suspended in medium. It's population was increased with incubation, reached top level of 29.0 Log copy No at the 24 hour and then decreased. In the meantime, DM digestion of rice straw showed the higher increasement from the 8 hour to the 24 hour than from the 0 hour to the 8 hour, and then a slowdown in increasing trend of digestibility. Attachments of F. succinogenes, R. flavefaciens and R. albus were detected immediately after start of in vitro rumen incubation. At the same time, the colonized bacterial share were respectively 34.5%, 84.4% and 67.9% in total population. All of them was reached the highest colonized bacterial share above 94.7% at the 4 hour incubation. However population of attached bacteria was shown the highest level at the 12 hour or the 24 hour incubation. Kinetics of colonization were formed area of top speed from the 12 hour to the 24 hour and respectively reached 10.33, 9.28 및 8.30 Log copy No/h/g DM at the 24 hour by F. succinogenes, R. flavefaciens and R. albus. The kinetics of rice straw degradation was formed top level of 0.95% DM/h at the 24 hour. The present results gave clear evidence that degradation of rice straw was increased with the development of total fibrolytic bacteria in process of rumen fermentation. Also, their attachment was largely occurred immediately after insertion of rice straw, the colonized bacteria was actively proliferated, and then degradation of rice straw was maximized.

• Animal Bioscience
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• v.34 no.6
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• pp.1038-1048
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• 2021

Objective: The study aimed to evaluate the effect of storage time and formic acid (FA) on fermentation characteristics, epiphytic microflora, carbohydrate components and in vitro digestibility of rice straw silage. Methods: Fresh rice straw was ensiled with four levels of FA (0%, 0.2%, 0.4%, and 0.6% of fresh weight) for 3, 6, 9, 15, 30, and 60 d. At each time point, the silos were opened and sampled for chemical and microbial analyses. Meanwhile, the fresh and 60-d ensiled rice straw were further subjected to in vitro analyses. Results: The results showed that 0.2% and 0.6% FA both produced well-preserved silages with low pH value and undetected butyric acid, whereas it was converse for 0.4% FA. The populations of enterobacteria, yeasts, moulds and aerobic bacteria were suppressed by 0.2% and 0.6% FA, resulting in lower dry matter loss, ammonia nitrogen and ethanol content (p<0.05). The increase of FA linearly (p<0.001) decreased neutral detergent fibre and hemicellulose, linearly (p<0.001) increased residual water soluble carbohydrate, glucose, fructose and xylose. The in vitro gas production of rice straw was decreased by ensilage but the initial gas production rate was increased, and further improved by FA application (p<0.05). No obvious difference of FA application on in vitro digestibility of dry matter, neutral detergent fibre, and acid detergent fibre was observed (p>0.05). Conclusion: The 0.2% FA application level promoted lactic acid fermentation while 0.6% FA restricted all microbial fermentation of rice straw silages. Rice straw ensiled with 0.2% FA or 0.6% FA improved its nutrient preservation without affecting digestion, with the 0.6% FA level best.

• Animal Bioscience
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• v.35 no.7
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• pp.999-1009
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• 2022

Objective: To improve the feeding value of rice straw (RS), this study evaluated the potential of rice straw fermented with Pleurotus sajor-caju (FRS) as dairy goat feed. Methods: Spent Pleurotus sajor-caju mushroom substrate was used as fungi inoculum to break the lignocellulose linkage of rice straw, which was solid-fermented at 25℃ to 30℃ for 8 weeks. The ruminal degradation of pangolagrass hay (PG), FRS, and RS were measured in situ for 96 hours in three dry Holstein cows, respectively. Effect of fungi fermented RS on milking performance was studied in feeding trials. A total of 21 Alpine goats a trial were divided into 3 groups: a control group in which PG accounted for 15% of the diet dry matter, and FRS or RS was used to replace the PG in the control group. Goats were fed twice a day under two 28-day trial in individual pens. Meanwhile, a 3×3 Latin square trial (14 days/period) was conducted to study the rumen digestion of three diets by using three fistulated dry goats. Rumen contents were collected for metabolite analyses every one to three hours on the last two days. Results: In situ study showed that fermentation could elevate the rumen degradable fraction and effective degradability of RS (p<0.05). Effective degradability of FRS dry matter was significantly increased from 29.5% of RS to 41.7%. Lactating trial results showed that dry matter intake and milk yield in the PG group and FRS group were similar and higher than those in RS group (p<0.05). The concentration of propionic acid and total volatile fatty acid in the RS group tended to be lower than those in PG group (p<0.10). There were no differences in rumen pH value and ammonia nitrogen level among the groups tested. Conclusion: Fermentation of rice straw by spent Pleurotus sajor-caju mushroom substrate could substantially enhance its feeding value to be equivalent to PG as an effective fiber source for dairy goat. The fermented rice straw is recommended to account for 15% in diet dry matter.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.4
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• pp.615-623
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• 1989

Three sheep fitted with rumen cannulae and abomasal cannulae were given daily 750 g (DM) of three diets consisting of straw-manure silage and barley mixture in the ratios of 75:25, 50:50 and 25:75. As the proportion of barley in the diet increased, there was an increase in the amount of OM apparently digested in the rumen and thole tract (P<.01). But ADF digestion was decreased. For the 25:75 diet the $NH_3-N$ content in the rumen showed the highest value, but the total VFA was the lowest. The rumen volume and dilution rate increased with increasing ratio of silage in diets. There were no significant differences between diets in abomasal NAN flow, and the bacterial-N for the 25:75 diet was 7.3 g N as compared with 9.2-9.6 g N for the other diets (P<.01). Rates of bacterial nitrogen synthesis in the rumen were 30.5, 24.1 and 14.9 g N per Kg OM apparently digested in the rumen for the 75:25, 50:50 and 25:75 diets, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.3 no.3
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• pp.195-203
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• 1990

Thirty-six yearling (18 bulls, 18 heifers) swamp buffaloes (Bubalus bubalis) with average liveweight $177{\pm}26kg$, were randomly allotted to receive 6 dietary treatments according to a $2{\times}3$ factorial arrangement in a completely randomized design (CRD). Factor A assigned for two types of straw; untreated rice straw (RS) and urea-treated (5%, w/w) rice straw (UTS). Factor B assigned for three ratio of roughage to concentrate (R:C) at 80:20, 50:50 and 20:80. Feeding trial lasted for 9 months during which respective feeds were offered at 3% body weight and adjusted at bi-weekly intervals using corresponding liveweights. Parameters measured under this experiment were feed intake, ruminal fluid for pH, $NH_3-N$, volatile fatty acids (VFA), liveweight change at bi-weekly intervals, carcass characteristics and cost-net profit analysis. It was found that intakes and digestion coefficients of DM, OM, CP except NDF and ADF were improved appreciably when ratio of concentrate increased. The average daily gain (ADG) and feed conversion ratio (FCR) were highest in group fed urea-treated rice straw at R:C levels of 20:80 (551.2 g/d, 10.7 kg/kg) and 50:50 (542.3 g/d, 10.6 kg/kg). It was obvious that FCR was best in the group fed on urea-treated rice straw (13.8 kg/kg) as compared to untreated rice straw fed-group (24 kg/kg). Carcass compositions of buffaloes measured resulted in 48.2 dressing percentage in all treatments offered at R:C levels of 50:50 and 20:80, however, loin eye area were 46.0, 53.6, 50.0 and $54.0cm^2$ for RS and UTS at respective levels of R:C. It was notable that carcass fat content was low which resulted in higher content of lean meat particularly in group fed UTS at 50:50 ratio R:C. Simple cost-net profit analysis was performed, it was found that net profits were obtained as follows 27, 30, -47, 44, 58, 22 $US/hd for respective treatment groups of RS and UTS at respective R:C levels. As shown, the best net profit resulted in group fed UTS at 50:50 R:C level.