Chopped Rice Straw Research Articles

Effect of water regimes and organic matters on transport of arsenic in summer rice ( Oryza sativa L.)

The arsenic contamination in soil-water-plant systems is a major concern of where, the groundwater is being contaminated with arsenic (above 0.01 mg/L) in the Indian subcontinent. The study was conducted with organic matter to find out the reducing effect on arsenic load to rice (cv. Khitish). It was observed that intermittent ponding reduced arsenic uptake (23.33% in root, 13.84% in shoot and 19.84% in leaf) at panicle initiation stage, instead of continuous ponding. A decreasing trend of arsenic accumulation (root > straw > husk > whole grain > milled grain) was observed in different plant parts at harvest. Combined applications of lathyrus + vermicompost + poultry manure reduced arsenic transport in plant parts (root, straw, husk, whole grains and milled grain) which was significantly at par (p > 0.05) with chopped rice straw (5 tons/ha) + lathyrus green manuring (5 tons/ha) in comparison to control and corresponding soils. A significant negative correlation of arsenic with phosphorus (grain P with arsenic in different parts R 2 = 0.627-0.726 at p > 0.01) was observed. Similarly, soil arsenic had a negative correlation with soil available phosphorus (R 2 = 0.822 at p > 0.001) followed by soil nitrogen (R 2 = 0.762 at p > 0.01) and soil potassium (R 2 = 0.626 at p > 0.01). Hence, effective management of contaminated irrigation water along with organic matter could reduce the arsenic build up to plants and soil.

Effects of Treating Whole-plant or Chopped Rice Straw Silage with Different Levels of Lactic Acid Bacteria on Silage Fermentation and Nutritive Value for Lactating Holsteins

Two experiments were carried out to investigate i) the effects of four levels of lactic acid bacteria inoculants (LAB; 0, 2×10 5 3×10 5 and 4×10 5 cfu/g fresh forage) and two physical forms of rice straw (whole and chopped rice straw) on silage fermentation quality and nutritive value of rice straw (RS) silage for lactating Holsteins and ii) the effects of the replacement of corn silage (CS) with different inclusion levels (0, 25 and 50%) of LAB treated RS on lactating performance of Holstein dairy cows. Rice straw packed with stretch film was ensiled for 45 d. The results showed that the higher level of LAB inoculants in the silage quadratically decreased pH, NH 3 -N and acetic acid concentrations and increased the contents of lactic acid and total organic acids. The CP content and DM losses in the silage declined linearly as the level of LAB addition was increased. Compared with whole-plant rice straw silage (WRS), chopped rice straw silage (CRS) dramatically reduced pH by 0.83. The concentrations of NH 3 -N were similar in WRS and CRS and both were less than 50 g/kg of total N. Chopping rice straw before ensiling significantly enhanced the lactic acid concentration and total organic acids content whereas the concentration of acetic acid declined. The CP, NDF and ADF content of CRS was 13.4, 5.9 and 10.2% lower than in WRS, respectively. Except for butyric acid concentration, significant interaction effects of inoculation level and physical form of RS were found on all fermentation end-products. Our findings indicated that milk yield and composition were not affected by different level of RS inclusion. However, because of the lower cost of WRS, cows consuming a ration in which WRS was partially substituted for CS had 3.48 Yuan (75% CS+25% WRS) and 4.56 Yuan (50% CS+50% WRS) more economic benefit over those fed a CS-based ration. It was concluded that the chopping process and LAB addition could improve the silage quality, and that substitution of corn silage with RS silage lowered the cost of the dairy cow ration without impairing lactation performance.

Effect of Elemental Sulfur Supplementation on Rumen Environment Parameters and Utilization Efficiency of Fresh Cassava Foliage and Cassava Hay in Dairy Cattle

Effect of sulfur (S) on utilization efficiency of fresh cassava foliage and cassava hay in dairy cows was evaluated using thirty-two I st -2 nd lactation Holstein-Friesian crossbred dairy cows. The experimental treatment was a 2x2 factorial arrangement in a randomized complete block design (RCBD) using two roughages (rice straw+fresh cassava foliage (FCF) and rice straw+cassava hay (CH)) and two elemental sulfur (S) levels (0.15 and 0.4% S of dry matter (DM)), respectively. Four dietary treatments (FCF+0.15, FCF+0.4, CH+0.15 and CH+0.4) were offered ad libitum in the form of a total mixed ration (TMR) with concentrate to roughage (chopped rice straw+chopped cassava foliage) ratio at 60:40. Fresh cassava foliage or cassava hay resulted in similar dry mater intake, rumen ecology parameters, total tract digestibility, blood chemistry, milk production and composition. However, HCN intake, blood and milk thiocyanate concentration were significantly higher (p<0.01) in cows fed fresh cassava foliage with no sign of potential toxicity. Dry matter intake, body weight changes, molar percentage of propionate in rumen, neutral detergent fiber (NDF) digestibility and nitrogen (N) retention of cows tended to be increased while DM digestibility (65.6, 72.7, 68.6 and 72.1% of total DM intake for the respective treatments), rumen bacteria population (1.4, 1.7, 1.6 and 1.7x10 11 cell/ml for respective treatments), fungal zoospore population (0.4, 0.6, 0.4 and 0.5x10 6 cell/ml for respective treatments), urinary allantoin (25.3, 28.0, 26.3 and 27.6 g/d for respective treatments), microbial N yield (136.0, 154.6, 142.8 and 151.3 g N/d for respective treatments) and milk protein content (3.4, 3.5, 3.2 and 3.5% for respective treatments) were significantly (p<0.05) higher in cows fed on supplemented sulfur at 0.4% of DM in comparison with 0.15% S-supplemented diets. Based on these results, it is concluded that cassava foliage could be used as a portion of roughage for dairy cows and supplementation of S would be nutritionally beneficial.

Organic Mulching on Carrot Yield and Quality

ABSTRACT Mulching can affect temperature in the first 20- to 30-cm depth in soils. The objectives of this study were to characterize the possibility of using organic based mulches to modify carrot (Daucus carota L.), cv. Forto Royal, plant growth and determine effects on yield and quality. Mulch treatments included rice (Oriza sativa L.) hulls, sawdust (Populus deltoids Bartram ex Marshall var. deltoides), and chopped rice straw. Total yield, root weight, root length, and total soluble solids for plants grown with organic mulches were better than the bare soil control. No significant differences were found in plant height, root diameter, inner and outer core diameter, root color, dry matter, and ash percentage due to treatment. Mulching with organic materials provided some benefit to root development, yield, and total soluble solids content and its use is recommended to promote the carrot root development.

EVALUATION OF ENRICHED COMPOST AND ITS ROLE IN SYNERGY WITH RHIZOBACTERIA AND N-FERTILIZATION FOR IMPROVING MAIZE PRODUCTIVITY IN SANDY SOIL

Chopped rice straw supplemented with differ-ent amendments, namely organic (farmyard ma-nure and vinass); bio (mixture of Trichoderma har-zianum and Trichoderma viridi) and mineral (rock phosphate, bentonite, elemental sulfur and com-mercial nitric acid) to prepare enriched compost. After elapsing of composting process the prepared compost was monitored for its physio-chemical and microbiological characteristics as well as some maturity indices. Afterwards, enriched compost was evaluated in synergy with rhizobacteria (mix-ture of Serratia sp and Paenibacillus polymyxa) and graded levels of N-fertilizer as integrated ferti-lizer strategy for improving the growth and produc-tivity of maize plants grown in sandy soil through two field experiments executed at Ismailia Agricul-ture Research Station during successive summer season of 2005 and 2006. Results of enriched compost monitoring revealed that this product has an acceptable degree of the main physio-chemical properties such as color, bulk density, WHC, pH, EC and C/N ratio. Also, enriched compost exhibit-ed a valuable degree of fertilizer value, which re-flected by its content from macro and micronutri-ents. This end product has a high degree of micro-biological traits, which exhibited through the high counts of the main groups of microorganism and remarkable values of dehydrgenase and nitrogen-ase activities. In addition, all examined maturity indices exerted that this product has a reasonable degree of maturity and it can applied to plants without causing phytotoxicity or immobilization. Results of field experiments showed that growth aspects of maize plants were extremely affected by the mineral fertilization rather than organic and/or bio one. However, the highest values of plant vigor and N-content were attained as a results of the integrated fertilization strategy, particularly when maize plants received 120kg N/fed in combination with compost (at rate of 5 ton/fed) and rhizobacte-ria. The maize yield and its attributes appeared high response to applied N-fertilizer levels and organic fertilization. Irrespective of bio-organic ferti-lization, addition of N-fertilizer at levels of 60, 90 and 120 kg N/fed led to increase the grain yield by 103.70, 141.12 and 174.77%, respectively over control treatment (30 kg N/fed). On the other hand, topdressing of soil with enriched compost led to increase the grain yield of maize by 19.70% and this percentage increase raised to 25.76% when the organic manuring was conjugated with rhizo-bacteria under any level of N-fertilizer. However, the highest yield of maize was achieved in case of synergy between the high dose of N-fertilizer and 5 ton/fed from enriched compost for rhizobacterial inoculated grains.

Effect of Level of Crude Protein and Use of Cottonseed Meal in Diets Containing Cassava Chips and Rice Straw for Lactating Dairy Cows

The effects of different levels of crude protein (CP) and cottonseed meal replacing for soybean meal in cassava chips and rice straw-based diets for mid-lactating cows (100-150 day in milk [DIM]), were studied using 32 multiparous Holstein Fresian crossbred dairy cows. Diets containing 10.5, 12.5, 13.7, 14.4% CP of the rations and 0, 12.1, 14.9, 17.8% cottonseed meal were fed to cows for 60 days. Thirty two cows were randomly divided into four dietary treatments using a Randomized complete block design. Four dietary treatments were offered in the form of total mixed ration (TMR) with concentrate to roughage (chopped rice straw) at 60:40 and offered ad libitum. Dry matter (DM) and neutral detergent fiber (NDF) intakes tended to linearly increase with increasing dietary CP levels. Intakes and digestibility of crude protein increased linearly with increasing dietary CP level (p<0.01). Crude protein digestibility of the 10.5% CP diet was lower (p<0.05) than that in diets with higher levels of CP, while there were no significant differences among the other three levels of CP (12.5, 13.7 and 14.4%). Daily milk yield tended to increase with increased CP from 10.5 to 14.4%. Income over feed in terms of USS/kg of milk increased with increased CP from 10.5 to 13.7% and decreased when the CP level was higher than 13.7% (quadratic effect p<0.09). Milk composition was not significantly affected by increasing level of CP, however there were relatively high contents of protein and fat among treatments. The proportion of milk-urea N (MUN), ammonia-N (NH 3 -N) and blood-urea N (BUN) were closely correlated and increased linearly with increasing CP levels (p<0.01). Balanced diet was found in diet containing 12.5 and 13.7% CP of the rations when BUN and MUN were used as indicators of the protein to energy ratio in the diet. Conclusions can be made that increasing dietary CP levels from 10.5 to 13.7% using cottonseed meal as the main source to completely replace soybean meal was beneficial to cows consuming rice straw and cassava chips based-diets. Increasing the CP level above 13.7% of total ration did not additionally improve milk yield and composition or net income.

Biodegradation of gossypol by the white oyster mushroom, Pleurotus florida, during culturing on rice straw growth substrate, supplemented with cottonseed powder

The capacity of the white oyster mushroom, Pleurotus florida to biodegrade gossypol was studied, when grown on rice straw supplemented with cottonseed powder. The mushroom fruiting bodies did not contain any residues of gossypol at concentrations of cottonseed powder ≡0.15–0.60% nitrogen contents of rice straw at the end of mycelial ramification. However, the cottonseed supplementation (at 0.30% N level itself) caused a doubling in the mushroom yield and its protein content, per unit weight straw substrate. The mushroom mycelium when grown on synthetic medium in liquid cultures was able to biodegrade gossypol. A pre-incubation period of 5 days before the addition of gossypol into the culture medium, an inoculum load ≡10 mg and an incubation period of 10 days at 25 °C caused the biodegradation of 100 μg gossypol. Increased concentrations of gossypol required increased duration and increased inoculum levels to effect biodegradation. However, the effect was more pronounced with an increase in inoculum density. The fungal monoculture when grown in rice straw (powder) (5%) + glucose (1%) liquid culture medium, showed an increase in hexosamine content and laccase activity that produced an increased degradation of gossypol over an incubation period from 5 to 25 days. Enzymic extracts of the mycelial monoculture raised on the chopped rice straw substrate when incubated with 100 μg of gossypol demonstrated its biodegradability; the increase in enzyme concentration showed enhanced gossypol degradation. This study adds to the world list of organic compounds that Pleurotus is able to biodegrade, and explains the cause of non-yellowing of the white oyster mushroom (P. florida) fruiting bodies, during culture on rice straw with supplementation of cottonseed powder for enhancing the mushroom yields.

Rumen Parameters and Urea Kinetics in Goats and Sheep

The effects of animal species and supplements on rumen fluid characteristics, plasma urea-N (PUN) concentration, plasma urea-N pool size, urea-N degradation in the gut and urea-N net flux (urea-N synthesis rate) were studied in goats and sheep, with some minor differences detected. The animals were fed either chopped rice straw ad libitum+200 g soybean meal (SBM), or chopped rice straw ad libitum+190 g soybean meal+300 g sago meal (SBM+SM) for 14 days. The supplements were isonitrogenous (80 g crude protein/animal/d). [14C]-urea was used as the marker for urea metabolism studies. Two animals from each species were fed either supplement in a cross-over design in two periods. The results showed that rumen pH was significantly (p<0.001) lower in animals fed SBM+SM than those fed SBM supplement. The ammonia concentrations of rumen fluid were significantly (p<0.01) higher in sheep (382.9 mg N/L) than goats (363.1 mg N/L) when fed SBM supplement but lower (282.5 mg N/L) than that of goats (311.0 mg N/L) when fed SBM+SM supplement. Total VFA concentrations were significantly (p<0.05) higher in animals fed SBM+SM supplement than those fed SBM supplement. Goats had significantly (p<0.01) higher molar proportions of acetate (79.1, 77.7%, respectively) than sheep (75.8, 74.0%, respectively) in both supplements. The molar proportion of acetate was significantly (p<0.05) higher, while that of butyrate lower in animals fed SBM supplement than those fed SBM+SM supplement. In animals fed SBM supplement, the molar proportion of propionate was significantly (p<0.01) higher in sheep (18.0%) than in goats (15.6%), but in animals fed SBM+SM, the molar proportion of butyrate was significantly (p<0.01) higher (9.6%) in sheep than in goats (7.2%). Plasma urea-N concentration, plasma urea-N pool size, urea-N degradation in the gut, urea-N net flux and the fraction of urea-C from the blood entering the rumen were not significantly different between goats and sheep fed either supplement. However, PUN concentration was significantly (p<0.05) lower in animals fed SBM+SM supplement (average of 13.8 mg N/100 ml) than in those fed SBM supplement (average of 16.5 mg N/100 ml). The urea net flux was significantly (p<0.05) higher in goats (average of 14.5 g N/d) than sheep (average of 12.9 g N/d), and animals fed SBM supplement showed higher (average of 14.9 g N/d) urea net flux than animals fed SBM+SM supplement (average of 12.9 g N/d) A significant (p<0.05) positive correlation was observed between urea-N net flux and urea-N degradation; urea-N net flux and pool size; urea-N net flux and urea excretion in the urine; and PUN and rumen ammonia in goats. While in sheep, significant (p<0.05) positive correlation was observed between urea-N net flux and urea excretion in the urine; and PUN and rumen ammonia.

Effects of Protein and Carbohydrate Supplements on Feed Digestion in Indigenous Malaysian Goats and Sheep

Experiments were conducted to determine the effects of soybean meal (SBM) as a source of protein and sago meal (SM) as a source of carbohydrate on in situ and in vivo digestibility of dietary components in four male goats (Kambing Katjang) and four male sheep (Malin) weighing 25-35 kg. Rumen volume, as well as rumen fluid dilution rate were also determined. The animals were housed in single pens with individual feeding and drinking troughs and each animal was fitted with a rumen fistula. They were fed two diets : chopped rice straw+200 g soybean meal (SBM), and chopped rice straw+190 g soybean rneal+300 g sago meal (SBM+SM). Rice straw was offered ad libitum. The supplements were isonitrogenous (80 g crude protein/animal/d), but the proportions of dry matter (DM), organic matter (OM), crude fibre (CF), neutral detergent fibre (NDF) and acid detergent fibre (ADF) were lower in the SBM supplement (191, 165, 11, 40, 15 g/animal/d for DM, OM, CF, NDF and ADF, respectively) than in the SBM+SM supplement (445, 423, 25, 102, 38 g/animal/d for DM, OM, CF, NDF and ADF, respectively). Two animals from each species were fed either supplement in a cross-over design in two periods. Each period lasted for four weeks. In situ and in vivo digestibility studies were carried out, followed by the determination of rumen volume and rumen fluid dilution rate. The results showed that straw DM and total DM intakes of goats (average of 48.7 g/kg W0.75, 72.7 g/kg W0.75, respectively) were significantly (p<0.01) higher than sheep (average of 35.6 g/kg W0.75, 61.6 g/kg W0.75, respectively), but OM, N and GE intakes were not significantly different between the two animal species. When the effect of supplements was compared, animals fed SBM+SM supplement had significantly (p<0.001) higher DM, OM and GE intakes than animals fed SBM supplement. Potential degradabilities of rice straw DM were significantly (p<0.01) higher in goats (average of 48.8%) than in sheep (average of 46.1%). The supplements had no significant effect on the potential degradabilities of DM, OM and NDF, but they had a significant (p<0.05) effect on the degradation rates of DM and NDF. The addition of sago meal in the diet reduced the degradation rates of DM and NDF of rice straw in the rumen. Potential degradability of DM of soybean meal was not significantly different between animal species as well as between supplements. Sago meal was highly degradable. At 24 h of incubation in the rumen, 90-95% of DM loss was observed. There was a significant interaction between animal species and supplements in the m vivo digestibility of ADF and GE. In animals fed SBM supplement, the in vivo digestibility of ADF was significantly (p<0.05) higher in goats (50.6 ± 4.22%) than in sheep (44.4 ± 3.21%), but digestibility of GE was significantly (p<0.05) higher in sheep (70.2 ± 1.93%) than in goats (63.0 ± 3.07%). The digestibility values of CP and OM were significantly (p<0.05) higher in sheep when compared to goats. Animals fed SBM+SM supplement showed significantly (p<0.05) higher DM and OM digestibility values than animals fed SBM supplement, but digestibility values of CP were significantly (p<0.05) higher in animals fed SBM supplement. Differences in in vivo digestibility values of CF and NDF were not significantly different between animal species or supplements. Water intake, rumen volume (1/kg W0.75), rumen fluid dilution rate and mean retention time were similar between the two animal species. However, rumen fluid dilution rate and mean retention time was significantly (p<0.01) affected by supplements. Animals fed SBM+SM had faster rumen fluid dilution rate and consequently shorter mean retention time.

Conjugated Linoleic Acid Concentrations in Adipose Tissues of Japanese Black Fattening Steers

In the present study, we investigated conjugated linoleic acid(CLA) concentrations in the adipose tissues from carcasses of Japanese Black fattening steers and was correlated with the roughage intake. Subcutaneous, intermuscular and peninephric fats were collected from 8 Japanese Black fattening steers with mean body weight of 670±79kg. The animals were fed with concentrate and chopped rice straw ad libitum for 11 months, from 15 to 26 months of age. Conjugated linoleic acid concentrations in subcutaneous, intermuscular and perinephric fats were 0.44, 0.34 and 0.25%, respectively. The difference in mean CLA concentrations among the adipose tissues was significant (P<0.01). The coefficients of correlation between the percentages of CLA in subcutaneous and intermuscular fat was 0.897 (P<0.01), in subcutaneous and perinephric fat was 0.680, and in intermuscular and perinephric fat was 0.643. The correlations between the proportion of the roughage to the total feed consumed and CLA concentrations in the subcutaneous fat, intermuscular fat and perinephric fat were 0.761 (P<0.05), 0.658 and 0.393, respectively. Roughage intake was significantly correlated with CLA concentrations in the subcutaneous fat. Relatively higher percentage of CLA was obtained in the subcutaneous fat of the beef cattle which had higher intake of fibrous feed. Results suggest that feeding management of beef cattle should be geared towards higher proportion of fibrous dietary intake to increase CLA, which is beneficial.

A study of plaster binding to prevent cracking which favours Triatomine infestation.

Poor housing has always favoured domiciliary Triatominae (R Briceno-Leon 1990, La casa enferma. Editorial Acta Cientifica Venezolana, Caracas, Venezuela, 149 p.). In the past, house improvement has been a feature of Brazilian National Control Programmes (RS De Brito 1968, As realizacoes do Departamento Nacional de Endemias Rurais no campo da profilaxia da doenca de Chagas, p. 560-574. In JR Cancado, Doenca de Chagas, Imprensa do Estado, Belo Horizonte, MG). In our study area of Mambai, Goias where residual insecticide spraying was iniated in 1980 (MTA Garcia-Zapata & PD Marsden 1992, Am J Trop Med Hyg 46: 440-443), we have only reported one house with persistent Triatoma infestans infestation which was plastered (MTA Garcia-Zapata et al. 1992 J Trop Med Hyg 95: 420-423). House plastering to produce smooth walls is an ancient technique for rural dwellings. For example mutton fat and sheeps wool were common binding agents for plastering rural cottages in England. In Brazil many colonial buildings have molasses or whale oil as binding agents. Poor hygiene is a major factor in the persistence of triatomines in the homes of Mambai (MTA Garcia-Zapata & PD Marsden 1994 Bol Of San Panam 116: 97110). House improvement restores pride in the home and better hygiene. To establish for Mambai municipality the best binding agents to be used in wall plastering we constructed six experimental walls (Fig.) of field brick of 1 m2 covered with roofing tiles to mimic the field situation. A control wall was plastered with a mixture of two parts earth, two parts sand and one part cement. On the other five walls an addition of one part of the following binding agents was made to the plaster namely chopped dried manioc stem, maize husk, rice straw, ground urucum fruit and cow faeces, all materials readily available to the subsistence farmer in Mambai. Mean yearly rainfall and temperature variation for the area during the observation time was as follows: temperature (°C): Max. 28.6 , Min. 19.5, Mean: 23.4; humidity (%): Max. 79, Min. 48, Mean: 66.6. Thirty months after construction inspection showed that the wall with most cracking was the control wall in which no binding agent had been used. However the cracks were so fine as to only permit egg laying and not bug entry. The only two walls without cracking were those where maize husk and rice straw had been used. These will be the formulations we will recommend to householders in Mambai planning replastering. It must be pointed out that the three basic ingredients of soil, sand and cement will vary from one area to another. Mambai on the high plateau of Central Brazil has red laterite arenaceous soil, cement made from incinerating local rock and a characteristic sand deposit. In areas where house improvement of the type mentioned here is contemplated these experiments will have to be repeated to establish the best mixture in that geological area to produce effective plastering. It is probable that the “Incas”, one of the most important and oldest indian cultures in South America, used maize formulations and other binding agents in such building construction. As the basic layer of domestic wall plastering the japanese used mud and chopped rice straw in traditional homes -shita-nuri(ES Morse 1961, Japanese homes and their surroundings, Dover Publications, New York, 372 pp.). Acknowledgements: to the DEPLAN, Ministerio do Meio Ambiente and Instituto Nacional de Meteorologia (INMET), Divisao de Meteorologia Aplicada, Banco de Dados Meteorologicos, Brasilia DF, for temperature and humidity data for the Mambai region.

The improvement of rice straw quality by urea-molasses treatment

A study was conducted in Balai Penelitian Temak Bogor to evaluate the effect of urea-molasses treatment on the quality of rice straw . Five levels of urea were 0%, 0.5%, 1%, 1 .5% and 2% and 4 levels of molasses were 0%, I%, 2% and 3%. The study was conducted based on factorial completely randomized design with 3 replications . Urea and molasses were mixed with 5 kg chopped rice straw and stored for 21 days in plastic bag . Parameters observed were dry matter, organic matter, crude protein, crude fibre, and silica contents . Nutritive value of rice straw was measured by proximate analysis and its nutrient digestibility by in-vitro using rumen liquid of fistulated Ongole-crossed cattle . The results showed that urea and molasses treatment on rice straw decreased the dry matter and silica contents but increased the crude protein content of rice straw (P<0 .01). Dry matter and organic matter digestibility of rice straw didn't show the significant different among urea treatment but highly significant increased (P<0.01) by the molasses treatment. It was concluded that urea and molasses treatment on rice straw could improve the quality so that by the levels of 1 .5% urea and 3% molasses produced the similar quality with napier grass . Key words: Rice straw, urea, molasses,nutritive value

Kinetics of composting rice straw with glue waste at different carbon: Nitrogen ratios in a semiarid environment

Abstract Glue waste was mixed with chopped rice straw at carbon:nitrogen (C:N) ratios of 1.5, 24.8, 30.3, 35.4, 39.9, and 116.3 and allowed to compost for 128 days under aerobic conditions. Moisture was kept constant at 65% (w/w). Organic carbon was determined at 0, 6, 14, 20, 26, 32, 44, 56, 68, 80, 92, 104, 116, and 128 days. Two parallel first‐order kinetics were found for describing the process of composting. Decomposition percentage increased linearly with the composting rate constant k 2 of fast‐decaying component. Composting rate constant k 1, A 0/C 0, and (C 0 — C)/C 0 were C:N ratio dependent. Optimal C:N ratio for obtaining early and efficient composting was 30.3. Half‐life of fast decaying component was within one week for different materials. Glue waste compost had a nitrogen loss of 44.7%. This study evolved a cheap and practical biotechnology to convert agricultural and industrial waste into a beneficial compost by increasing decomposition rate, reducing pungent odor of glue waste, and narrowing C:N ratio to acceptable limits.

Nutritive value of rice straw ( Oryza sativa) ensiled with animal excreta and rumen digesta

Three types of silages prepared on a commercial scale contained rice straw and either cattle faeces at 40% (CD40), poultry excreta at 40% (PD40) or rumen digesta at 50% (RD50) (fresh weight basis). These proportions were based on the results of a preliminary study in vitro. After a 45-day ensiling period, all the silages were golden yellow in colour with a pleasant aroma and soft texture, indicating optimum fermentation. Counts of total bacteria and coliforms were negligible. The crude protein content of the dry matter (DM) of the silages was 8.9–11.8%. Four experimental diets containing (1) 1.2 kg concentrate mixture plus ad libitum chopped rice straw, (2) CD40 silage, (3) PD40 silage and (4) RD50 silage were tested with four fistulated cross-bred bulls (Ongole × Holstein-Friesian) to assess nutrient digestibility and utilization, and rumen fermentation patterns. Voluntary intake of DM was higher (7.0 kg) with PD40 ( P < 0.01) than with the other diets which ranged from 4.4 to 6.4 kg. Digestibility of DM, organic matter (OM), crude protein (CP) and crude fibre (CF) and, for Diets 1–4, was: DM - 52.4, 58.1, 52.6 and 61.3; OM - 56.4, 61.1, 57.0 and 64.3; CP - 49.5, 51.2, 54.0 and 61.4; CF - 69.4, 73.8, 69.9 and 76.6. However, the differences were not statistically significant. All the animals were in positive nitrogen, calcium and phosphorus balance. Rumen liquor concentrations were: total N - 54.9, 42.5, 64.9 and 34.9; ammonia N - 4.7, 1.1, 5.9 and 1.1; residual N - 19.3, 14.3, 20.3 and 12.5; food and protozoal N - 27.5, 20.7, 37.1 and 17.9 mg per 100 ml with Experimental Diets 1, 2, 3 and 4, respectively. Total N, NH 3-N and food and protozoal N were higher ( P < 0.01) with Experimenttal Diet 3 than with the other diets. The three silage diets gave a significantly higher pH and lower volatile fatty acid concentration of rumen liquor than the control diet.

Biogasification of cattle dung and cattle dung—rice straw mixture at different solid concentrations

Experiments were carried out, using batch digesters, to study the effect of solid concentration on gas production. Nearly the same amount of gas was produced per gram of solids converted when the solid concentration of the cattle dung slurry was 7·7%, 10·2% or 14·8%. A larger percentage of the solids was converted when the solids concentration was high. The percentage of methane in the gas showed little variation with the change in the solids concentration. A mixture of cattle dung and chopped rice straw in the ratio of 1:2 (on a dry weight basis) and containing 15·2% solids compared well with cattle dung slurry in conversion of solids and production of gas.

Effect of different sources of urease on the treatment time and digestibility of urea-ammonia treated rice straw

Chopped (2–3 cm) rice straw (var. H 4) was treated with urea solution (4 g/100 g dry matter in 100 ml water) alone or with a source containing urease enzyme. Five sources containing urease were used: soya bean seeds, watermelon seeds, pumpkin seeds, jack bean seeds and winged bean seeds. Each of the sources was included at 3 levels: 2, 4 or 8 g/100 g treated-straw dry matter. Untreated straw and those treated with urea solution alone for periods up to 21 days were used as controls. The urease sources, their levels, treatment time and their interactions produced significant ( P < 0·01) effects. Inclusion of a urease reduced the treatment time to less than 5 days and at the same time produced IVO MD values similar to 14 to 21 days treatment without urease. Untreated straw had an IVO MD of 40%.

Urea-ammonia treatment of rice straw to improve its nutritive value for ruminants

Three experiments were conducted to evaluate the effectiveness of urea as a source of ammonia in an ‘ensiling’ process for improving the nutritive value of chopped rice straw. In Experiment 1 rice straw treated with six levels of urea was ensiled in sealed polythene bags for periods varying from 1 to 6 weeks. In vitro digestibility increased significantly with increasing level of urea but ensiling beyond 3–4 weeks had no further effect. The optimum level of treatment appeared to be around 4% urea with an ensiling period of 3–4 weeks. In Experiment 2 two levels of urea (4% and 8%) were used to ensile rice straw for 4 weeks. These two treatments were compared with a control treatment having 4% urea sprinkled over the straw prior to feeding, using growing sheep fed ad libitum on straw with 100 g concentrate mixture per animal per day. The ensiling process had a significant effect on digestibility. Doubling the quantity of urea had no effect on digestibility but voluntary dry matter (DM) intake increased by 25%. In Experiment 3 the loss of urea as ammonia, on exposure of ensiled straw to the atmosphere, was estimated as 25% over a period of 2h. It is concluded that rice straw can be successfully upgraded in feeding value by urea-ensiling for 3–4 weeks. More research is, however, required before the method is extended to the farmer.

The effect of diet supplements and gamma irradiation on dissimilation of low-quality roughages by ruminants: III. Effects of feeding gamma-irradiated base diets of wheaten straw and rice straw to sheep

SUMMARYResults of two experiments in which gamma-irradiated low-quality cereal straws were fed ad libitum to sheep, with and without supplements, are reported.In Exp. I 12 adult Merino wethers were fed chopped wheaten straw irradiated at 50 Mrad or non-irradiated wheat straw, each roughage was fed with and without a supplement of urea, minerals and vitamins. In Exp. II 16 adult Merino wethers were fed diets of chopped rice straw or chopped rice straw irradiated at 25, 50 or 75 Mrad; each of these roughages was fed with and without a supplement of casein, minerals and vitamins.Gamma-irradiated diets were invariably associated with reduced mean retention times of undigested feed particles in the digestive tract, and a depressed apparent digestibility of dietary dry matter. Voluntary feed intake of sheep given unsupplemented wheat straw irradiated at 50 Mrad was not significantly affected; nor was the voluntary feed intake of sheep fed unsupplemented irradiated rice straw. Irradiation depressed apparent dry-matter digestibility of unsupplemented wheat straw by 5·2 percentage units; irradiated rice straw diets were depressed by 20·2 (25 Mrad); 9·0 (50 Mrad) and 27·2 (75 Mrad) percentage units compared to non-irradiated diets.Supplementation of irradiated wheat-straw diets tended to restore them to a nutrient worth approximating their original levels in terms of digestibility and intake. Supplementation of rice-straw diets increased voluntary feed intake, because mean retention time was reduced, but diet dry-matter digestibility remained depressed. Supplementation always increased the animals’ state of nitrogen balance; irradiation per se had little effect.Distribution of gastro-intestinal-tract dry-matter content showed a strong tendency for a greater proportion of the ingesta to be located in the hind gut of animals fed irradiated rice-straw diets, thus confirming the enhanced rate of passage of these diets through the tract as determined by the use of dual stained feed-particles. For sheep fed wheat straw the average mean retention time for non-irradiated particles was 50·9 % greater than for irradiated particles. For rice straw diets non-irradiated feedparticles had mean retention time (pooled across supplementation and irradiation treatments) 30·8% greater than for irradiated particles.Distinct changes occurred in the ratio of acetic to propionic acid in the rumen liquor of sheep fed irradiated diets which are suggestive of an alteration in species composition of the foregut microbial population.Evidence is presented for the presence in irradiated diets of a factor or factors toxic to the ruminal microbiota.Irradiation at the levels used decreased feed particle size, but any advantage so obtained was offset by an enhanced rate of passage of feedstuff through the tract with consequent depression in digestibility. It is concluded that further work is required to elucidate the effects reported and to further establish optimum conditions for use of gamma irradiation as a technique in the treatment of low-quality roughages for use by ruminants.

埋草の生化學の研究

The material of silage was Astragalus sinicus L. The additional substances used in the present experiment were A. I. V., -acid, DEFU-solution, formic acid, common salt, saltpeter, bleaching powder, salicylic acid, carbon disulphide, formic acid with formalin, wheat bran, rice bran, corn meal, rice straw meal, sweet potato meal, potato, and grated sweet potato. The most excellent silage was made by the addition of formic acid. Formic acid with formalin is considerably effective within the range of the quantity of the present experiment, but in some measure inferior to formic acid alone and mineral acid. In the case of ensiling the material of high moisture content, it is advantageous that the bottom of a silo would be filled with rice straw meal or chopped rice straw as basal layer in order to absorb the juice exuded from the material. Moreover, a good silage may be obtained also from this rice straw meal.