Unit Of Dry Matter Research Articles

Performance and welfare of high-yielding dairy cows subjected to 5 or 8 cooling sessions daily under hot and humid climate

The objectives were to determine the effects of cooling of high-yielding dairy cows under a hot and humid climate on intake, milk yield, rumination time, and welfare parameters. Forty-two multiparous Israeli Holstein dairy cows were divided into 2 treatment groups and were housed in an open barn divided into 2 pens. The groups were subjected to different cooling schedules, in a crossover design as follows: cows were exposed to 5 or 8 cooling sessions per day (designated 5CS and 8CS, respectively) in the holding area of the milking parlor. Each period lasted 4 wk, and then treatments were switched for another 4-wk period. Each cooling session lasted 45min, comprising cycles of 30s of showering and 4.5min of ventilation without showering. Respiration rate and rectal temperature were recorded twice per week (Monday and Thursday) at 0630 and 1600h. Rumination and lying times were recorded automatically. Rectal temperatures were 0.16 and 1.08°C lower in 8CS than in 5CS cows in the morning and afternoon, respectively. Respiration rate was lower in 8CS than in 5CS cows in the morning (49.1 and 54.6 breaths/min, respectively), and more so in the afternoon (50.0 and 83.0 breaths/min, respectively). Dry matter intake and milk yields were 9.3 and 9.6% higher in the 8CS than in the 5CS cows (27.0 vs. 24.7 and 40.1 vs. 36.6kg/d, respectively), with no differences in milk fat and protein contents. Daily rumination time was 7.4% longer in the 8CS than in the 5CS (440.1 and 409.6min/d, respectively); however, rumination time per unit of dry matter or neutral detergent fiber consumed was higher in the 5CS than in the 8CS cows. Although the 8CS cows moved 3 times more to the milking area for extra cooling sessions than the 5CS ones, they spent 9.9min/d more than the 5CS ones in lying down (484.4 and 474.5min/d, respectively), and used more of their free time (excluding milking and feeding time) in resting than the 5CS cows: 52.0 and 43.9%, respectively. It appears that increasing the cooling frequency from 5 to 8 times per day improved their feeling of welfare, so they could spend more time lying and ruminating. In conclusion, increasing the cooling frequency of high-yielding dairy cows under hot and humid conditions from 5 to 8 times a day increased their intake and milk yield, and lowered their respiration rate and rectal temperature. Moreover, the 8CS cows spent more time resting than 5CS cows, an indication that increasing cooling frequency improved animal welfare.

Kinetics of methane fermentation yield in biogas reactors: Genetic variation and association with chemical composition in maize

Abstract Maize ( Zea mays L.) is the most competitive crop for methane production in Germany. Methane fermentation yield per unit of dry matter (MFY) is a determinant of methane yield, but little information is available on this trait. Our objectives were to investigate the kinetics of MFY during fermentation of maize, estimate quantitative-genetic parameters for different traits related to MFY and examine the relationship of MFY with chemical composition and silage quality. Whole-plant material of 16 inbreds and their 32 testcrosses was analyzed for MFY over 35 days of fermentation using a discontinuous laboratory assay. Data were also generated on chemical composition and in vitro digestible organic matter (IVDOM). Significant genotypic variances and high heritabilities were observed for MFY at early fermentation stages (up to 5 days) probably due to different concentrations of easily degradable chemical components. However, genotypic variances and heritability of MFY reduced as fermentation progressed, because of complete or partial degradation of all chemical components. Further, there were strong correlations of MFY with chemical components at early fermentation stages but not at later stages. Therefore, MFY at later stages, which is closer to potential MFY, does not seem to be amenable to selection. High heritability of IVDOM and its strong correlation with MFY in testcrosses indicated its possible use for preliminary or indirect selection. Keeping in view the magnitude of genetic variance that was low for MFY and high for dry matter yield (DMY), the other component of methane yield, more emphasis on breeding for DMY seems appropriate.

Phenology, heat unit accumulation and dry matter partitioning behavior of two rice cultivars transplanted on different dates

Phenology, heat unit accumulation and dry matter partitioning behavior of two rice cultivars transplanted on different dates

Digestible nutrients and available (ATP) energy contents of two varieties of kiwifruit (Actinidia deliciosa and Actinidia chinensis)

A model, which combines a dual in vivo–in vitro digestibility assay and stoichiometric relationships describing nutrient catabolism, has been recently developed to allow prediction of the available energy (AE) content of a food in terms of its ATP yield. The model uses the growing pig as an in vivo model for upper gastrointestinal tract digestion in humans. Terminal ileal digesta from the pig are incubated with human faecal inocula (in vitro fermentation model) to simulate human hindgut fermentation. The respective in vivo and in vitro digestibility assays provide predictions of the ileal absorbed and hindgut-fermented nutrient contents of a food which are then used to predict ATP production post-absorption, based on known stoichiometric relationships. In this study, the model was used to determine the AE contents of fresh, ripe Hayward (Actinidia deliciosavar Hayward) and Hort16A (Actinidia chinensis var Hort16A) kiwifruit. Kiwifruit pulp, containing 3gkg−1 of titanium dioxide, included as an indigestible marker, was fed to growing pigs and terminal ileal digesta were collected. Ileal nutrient digestibilities were determined. A sample of digesta was incubated in vitro with a fresh human faecal inoculum and the fermentable organic matter determined. The predicted available (ATP) energy contents of the Hayward and Hort16A kiwifruits were 5.9 and 6.2kJg−1 dry matter, respectively, approximately 44–47% of the determined apparent digestible energy (ADE) content. The AE contents of the kiwifruit, expressed relative to the AE content of dextrin (a highly digestible source of glucose) were 0.57 and 0.61 for Hayward and Hort16A, respectively. Comparable ratios for metabolisable energy (ME) were 0.74 and 0.73. The predicted AE from kiwifruit was much lower than the predicted ME from kiwifruit when compared to dextrin. The ME values overestimate the energy content of kiwifruit that is available to the cell. AE was not only lower than ME but the two energy systems ranked the kiwifruit types differently in terms of energy supply to the body. The relatively low energy content per unit of dry matter and high water content of kiwifruit make kiwifruit an ideal weight loss food.

Determination of Methane Fermentation Yield and its Kinetics by near Infrared Spectroscopy and Chemical Composition in Maize

Maize ( Zea mays L.) is the most commonly used substrate for methane production through anaerobic fermentation and is gaining further importance in Germany. Laboratory assays used for the determination of methane fermentation yield (MFY), i.e. the amount of methane produced per unit of dry matter, are complex and costly. Thus, the adoption of near infrared (NIR) spectroscopy, which is already successfully used for fast and cost-effective examination of animal feeds, would remedy this problem. The objectives of this study were to examine the potential of employing NIR spectroscopy to predict MFY as measured in a discontinuous fermenter, investigate the reliability of prediction of parameters related to the kinetics of MFY and compare models based on NIR spectroscopy with that on chemical composition for reliable prediction of MFY. Samples of dried whole plant material from 55 maize genotypes, grown in six environments, were analysed for their MFY using a discontinuous fermentation assay for different fermentation times. Further, chemical composition of the samples was analysed and NIR spectra were measured. Calibration models were developed to predict MFY and related traits based on NIR spectroscopy or chemical composition. Prediction of MFY after a short fermentation time ( R2= 0.88 after five days) was better than after complete fermentation ( R2= 0.77 after 35 days). Chemical composition models were always inferior to NIR spectroscopy models and showed a strong decrease in performance to predict MFY with ongoing fermentation time. The superiority of NIR spectroscopy is most likely attributable to higher information content in the NIR spectra. The fast determination of MFY by NIR spectroscopy will enable the examination of a larger number of samples and, therefore, allow for the use of MFY in maize breeding for biogas production.

Yield comparison for synthetic-derived bread wheat genotypes with different water uptake abilities under increasing soil water deficits

The drought stress in the rain-fed regions of West Asia and North Africa strongly depends on residual soil water available for the reproductive plant growth. The water uptake ability (i.e. water consumption per unit dry matter per day) of three synthetic-derived bread wheat genotypes, SYN-8, SYN-10 and SYN-15, and their parental variety Cham 6 were examined under controlled conditions. In addition, yield performance was compared under one artificial environment with supplemental irrigation and ten rain-fed environments at two locations over five cropping seasons. Large differences were found in water uptake ability among the four wheat genotypes; SYN-8 had the highest and SYN-10 the lowest ability. These differences were reflected in decrease of soil water content and increase of leaf temperature after irrigation. Under field conditions of supplemental irrigation, there were no significant differences in grain yield among genotypes Cham 6, SYN-8 and SYN-10; however, SYN-15 had lower grain yield due to low...

Accumulation and distribution of arsenic and cadmium by tea plants

It is important to research the rules about accumulation and distribution of arsenic and cadmium by tea plants, which will give us some scientific ideas about how to control the contents of arsenic and cadmium in tea. In this study, by field investigation and pot trial, we found that mobility of arsenic and cadmium in tea plants was low. Most arsenic and cadmium absorbed were fixed in feeding roots and only small amount was transported to the above-ground parts. Distribution of arsenic and cadmium, based on their concentrations of unit dry matter, in tea plants grown on un-contaminated soil was in the order: feeding roots>stems approximately main roots>old leaves>young leaves. When tea plants were grown on polluted soils simulated by adding salts of these two metals, feeding roots possibly acted as a buffer and defense, and arsenic and cadmium were transported less to the above-ground parts. The concentration of cadmium in soil significantly and negatively correlated with chlorophyll content, photosynthetic rate, transpiration rate and biomass production of tea plants.

Adjusting worm egg counts for faecal moisture in sheep

The number of eggs from gastrointestinal nematodes per gram of faeces (worm egg count WEC) is commonly used to determine the need for anti-parasite treatments and the breeding value of animals when selecting for worm resistance. Diarrhoea increases faecal moisture and may dilute the number of worm eggs observed. To quantify this effect, egg counts in sheep at pasture were simulated by dosing 15 animals with chromic oxide particles. The simulated WEC diminished as faecal moisture increased. When faeces were dried, simulated WEC per unit dry matter was not influenced by the amount of faecal moisture present prior to drying. The results suggest that adjustment for faecal moisture may provide an improved estimate of FEC. Drying faeces to calculate the WEC per unit dry matter would provide such an adjustment but may not be practical for industry application. In the past, the CSIRO McMaster Laboratory has used an adjustment factor developed by Gordon based on the classification of faecal consistency derived from the morphology of faeces. To examine the utility of an adjustment factor based on faecal consistency score (FCS), the relationships between FCS and simulated WEC and dry matter were examined. Dry matter and simulated WEC exhibited an exponential decline as FCS increased. The relationship between FCS and dry matter was further examined in 368 samples collected over 12 months from sheep at pasture, where it was observed that dry matter showed a linear decline as FCS increased. Adjustment factors based on dry matter were similar to those proposed by Gordon however adjustment factors predicted from simulated WEC diverged from the remainder for FCS > 4. As no samples scored FCS 5 in the study of simulated FEC, the adjustment factors based on the larger study that included samples with FCS 5 was therefore considered more robust. Adjustment factors were given by the equation: WEC estimated = (WEC observed/(34.21 − 5.15 FCS)) × 29.06. This equation estimates for samples with FCS > 1 the WEC that would be expected if the samples were FCS 1, the faecal consistency score for normal faeces. The impact of adjustment of observed WEC for faecal moisture predicted by FCS on decision points for treatment and on estimated breeding values requires further examination.

Optimization of Reaction Conditions for Enzymatic Viscosity Reduction and Hydrolysis of Wheat Arabinoxylan in an Industrial Ethanol Fermentation Residue

This study examined enzyme-catalyzed viscosity reduction and evaluated the effects of substrate dry matter concentration on enzymatic degradation of arabinoxylan in a fermentation residue, "vinasse", resulting from industrial ethanol manufacture on wheat. Enzymatic catalysis was accomplished with a 50:50 mixture of an enzyme preparation from Humicola insolens, Ultraflo L, and a cellulolytic enzyme preparation from Trichoderma reesei, Celluclast 1.5 L. This enzyme mixture was previously shown to exhibit a synergistic action on arabinoxylan degradation. The viscosity of vinasse decreased with increased enzyme dosage and treatment time at pH 5, 50 degrees C, 5 wt % vinasse dry matter. After 24 h of enzymatic treatment, 76-84%, 75-80%, and 43-47%, respectively, of the theoretically maximal arabinose, xylose, and glucose releases were achieved, indicating that the viscosity decrease was a result of enzyme-catalyzed hydrolysis of arabinoxylan, beta-glucan, and cellulose. In designed response surface experiments, the optimal enzyme reaction conditions with respect to pH and temperature of the vinasse, the vinasse supernatant (mainly soluble material), and the vinasse sediment (mainly insoluble substances) varied from pH 5.2-6.4 and 41-49 degrees C for arabinose release and from pH 4.9-5.3 and 42-46 degrees C for xylose release. Even though only limited hydrolysis of the arabinoxylan in the vinasse sediment fraction was obtained, the results indicated that the same enzyme activities acted on the arabinoxylan in the different vinasse fractions irrespective of the state of solubility of the substrate material. The levels of liberated arabinose and xylose increased with increased dry matter concentration during enzymatic hydrolysis in the vinasse and the vinasse supernatant, but at the same time, increased substrate dry matter concentrations gave corresponding linear decreases in the hydrolytic efficiency as evaluated from levels of monosaccharide release per weight unit dry matter. The study thus documents that enzymatic arabinoxylan hydrolysis of the vinasse significantly decreases the vinasse viscosity and that a compromise in the dry matter must be found if enzymatic efficiency must be balanced with monosaccharide yields.

Carbon content variation in boles of mature sugar maple and giant sequoia

At present, a carbon (C) content of 50% (w/w) in dry wood is widely accepted as a generic value; however, few wood C measurements have been reported. We used elemental analysis to investigate C content per unit of dry matter and observed that it varied both radially and vertically in boles of two old-growth tree species: sugar maple (Acer saccharum Marsh.) and giant sequoia (Sequoiadendron giganteum (Lindl.) Bucholz). In sugar maple there was considerable variation in tree ring widths among four radii for particular annual layers of xylem, revealing that the annual rate of C assimilation differs around the circumference and from the base of each tree to its top, but the observed variation in C content was unrelated to diameter growth rate and strongly related to the calendar year when the wood was formed. Carbon content in sugar maple wood increased in an approximately linear fashion, from < 50 to 51% from pith to cambium, at both the base and top of the boles. In giant sequoia, C was essentially constant at > 55% across many hundreds of years of heartwood, but it declined abruptly at the sapwood-heartwood boundary and remained lower in all sapwood samples, an indication that heartwood formation involves anabolic metabolism. Factors that may be responsible for the different C contents and trends with age between sugar maple and sequoia trees are considered. Tree-ring data from this study do not support some of the key assumptions made by dendrochronology.

Effects of forage type on particle size distribution of ruminal digesta and faeces of non-lactating cows fed high quality forage

This experiment was conducted to determine the effects of forage type on particle comminution in the rumen and on the critical particle size (CPS) for escape from the rumen in cattle fed high-quality forages at maintain allowance of NRC. Twelve ruminal fistulated non-lactating Holstein cows were offered one of four forage diets (long alfalfa hay (ALH), chopped alfalfa round bale silage (ALS), long orchard grass hay (OGH), and chopped corn silage (CS) with similar dry matter digestibility using a random block design. Whereas the eating time per unit of dry matter (DM) intake was similar for ALH and OGH, mean particle size (MPS) of the ruminal digesta at 3-h post feeding for ALH was lower than that for OGH, and was similar to those for ALS or CS. The ruminating time per unit NDF intake for OGH was lower than those for other diets. MPS of the ruminal digesta at 24-h post-feeding for OGH was significantly lower than that for CS, and was similar to those for ALH or ALS. From these results, a large proportion of the particle size reduction seemed to occur during rumination for OGH, and a large proportion of the particle size reduction seemed to occur during eating for ALH. The weight percentage of faecal DM retained on the 1-mm screen was 28.0%, 25.2%, 12.6%, and 26.2%, for ALH, ALS, OGH and CS, respectively. The MPS of the faeces in the cows fed was 309, 181, 104 and 514 ìm for ALH, ALS, OGH and CS, respectively. These results indicate that the critical particle size for escape from the reticular-rumen in non-lactating cows appeared to be larger than 1.18 mm and the particle size reduction and the passage of digesta from the rumen seemed to be due to factors intrinsic to the forage.

Productivity and water relations of burnt and long-unburnt semi-arid shrubland in Western Australia

This study provides a comparison between vegetation of relatively recent and long-unburnt shrubland in terms of structural and functional groups, annual net primary productivity and water relations. Adjacent areas of vegetation long-unburnt or burnt 5 years previously were compared within a remnant block of Acacia–Allocasuarina–Melaleuca arid shrubland at Kalannie, south west Western Australia. Species were classified according to growth and life form, fire response, phenology and rooting morphology and densities, mean plant above-ground dry weights and shoot:root dry mass ratios of each assessed. Species compositions, seedling densities and absence of recruitment in the long-unburnt area suggested marked dependence on fire in maintenance of biodiversity. Comparisons of above-ground standing dry biomass and annual net primary productivity of total (above-ground plus below-ground) dry matter showed the 4.09 kg m−2 biomass of long-unburnt vegetation to be increasing at 0.52 kg m−2 year−1 versus 0.45 and 0.18 kg m−2 year−1 for vegetation of the burnt area. Water relations of soils indicated consistently wetter profiles in burnt than long-unburnt areas and no deep drainage during the year of study. Lower water stress of key species in burnt than long-unburnt areas were indicated by less negative pre-dawn water potentials and higher stomatal conductance during the year of study and more negative carbon-isotope composition (δ13C) in wood laid down over the past 5 years. Budgets for water use were estimated for both sites and compared with annual net primary productivities. Data suggested much greater transpiration loss per unit dry matter gain by the rapidly growing plants at the burnt site (437 ml H2O g−1 DM) than by the plants of the long-unburnt community (92 ml H2O g−1 DM). Results are discussed in relation to composition and functioning of other Western Australian ecosystems. It is clear that time since fire affects productivity and water-use of vegetation of semi-arid shrublands and is therefore an important consideration for management and protection of remnant vegetation.

The effect of drying on unsaturated fatty acids and trypsin inhibitor activity in soybean

A study was conducted to assess and compare the effect of forced convection drying (FC) and microwave assisted drying (MW) on some unsaturated fatty acids and trypsin inhibitor activity (TIA) in soybeans. Samples were collected at regular intervals during drying at 60 °C (for food purposes), 40 °C (for seed purposes) and 100 °C (to simulate harsh conditions). All samples were dried to a final moisture content (MC) of 10 or 13% before being analyzed. Treated samples contained significantly lower quantities of unsaturated fatty acids ( P<0.05) per unit dry matter than untreated samples and MW was less destructive to fatty acids and TIA than FC. Although fatty acid destruction was more rapid at higher temperatures, the extent of degradation was dependent on both the drying temperature and drying time. Soybeans dried using FC contained acceptable low levels of TIA, making them adequately processed for food purposes, but suffered greater degrees of fatty acid degradation. Soybeans dried using MW retained higher levels of (TIA). Recoveries were >84%.

Logistic rice model for dry matter and nutrient uptake

The temporal variation of cumulative dry matter can be represented by a sigmoidal curve and the temporal variation of nutrient uptake follows this characteristic shape. Therefore, modeling the temporal variation of cumulative dry matter allows estimating nutrient uptake along the crop cycle. The objective of this study was to propose a sine model to estimate dry matter and macronutrient uptake, and to estimate the moments of maximum N and K uptake rates for the rice crop. The field experiment was carried out on a wetland area of Piracicaba, SP, Brazil, consisting of an Humic Haplaquept. The chosen rice variety was IAC 103, a middle season cycle and high yield. Observed variables were dry matter of different plant parts (root, leaf and stem, and panicle) and macronutrient contents per unit dry matter. A sine model was proposed for the cumulative variation of these variables, based on biological events that occurred during the crop cycle. The temporal variation of nutrient uptake was estimated and a lower accuracy was observed for K uptake. The maximum absorption rate for N and K was found at 56% of the relative development of the crop, corresponding to 60 days after emergence in this experiment. The proposed model presented a satisfactory behavior to define the order of magnitude of estimated dry matter and macronutrient uptake by the rice crop and maximum N and K uptake rates.

The effect of dry matter concentration of liquid diets on the growth performance of grower-finisher pigs

There is a considerable body of information on the voluntary feed intake of pigs fed on dry diets. However, there is a paucity of information on the factors affecting feed intake of pigs fed liquid diets. Pigs have a limit to their volumetric intake and will normally maximise dry matter intake when fed dry diets, ad libitum. For pigs fed dry feed the requirement for water per unit of dry matter will be dependent upon the composition of the feed and the requirement for renal clearance of nitrogen and minerals. What is not clear, is whether presenting the feed mixed with water results in excessive water intake that produces a point loading of the stomach, which in turn limits voluntary feed intake, i.e. whether physical bulk limitations override the normal homeostatic control. Therefore, it is not possible to extrapolate from data generated with dry fed pigs and anticipate voluntary intake of pigs fed dilute liquid diets. The aim of this study was to determine the effect of dry matter concentration of liquid feed on feed intake and growth performance of grower-finisher pigs.

Regrowth and Nutrient Composition of Different Plant Organs in Grass-clover Canopies as Affected by Phosphorus and Potassium Availability

Regrowth after cutting and the distribution of nitrogen (N), phosphorus (P) and potassium (K) in different plant organs of white clover and perennial ryegrass growing in pure or mixed swards were investigated under field conditions in a soil with a low-to-moderate availability of P and K. In all treatments, white clover constituted more than 70% of the above-ground biomass in the mixed swards. The petioles were the dominant pool of dry matter throughout regrowth and contained the greatest amounts of N, P and K. Increased supply of P and K increased the growth of ryegrass, but not that of white clover in the mixed swards. The increased competition from ryegrass led to a decline in the yield of white clover laminae as well as in the N content per unit of dry matter in laminae, petioles and stolons. The P content of all white clover organs also declined following P application to the mixed swards, whereas K application increased their K contents. In the pure swards of ryegrass and white clover, yields and contents of N, P and K in the dry matter were either not affected or increased following P and K application. It was concluded that commonly-used defoliation heights may remove 80% or more of the nutrient and dry matter pools located in the petioles but the remaining quantities of dry matter and nutrients in the petioles will normally exceed the corresponding quantities in the stolons.

Effect of rare earth elements on growth and nutrition of coconut palm and root competition for these elements between the palm and calotropis gigantea

Absorption of rare earth elements (REEs) namely lanthanum (La), cerium (Ce), praseodymium (Pr), and neodymium (Nd) by coconut, competition between coconut and Calotropis gigantea L. for these elements in mixed culture and the effects of the REEs on growth and nutrition of the palm were studied in a pot culture. At a low rate of application, REEs promoted root growth in coconut, but at a higher level, absorption of phosphorus (P) and zinc (Zn) by the palm was reduced significantly. Absorption of REEs by the palm tended to increase with increasing application rates, but the increases were not statistically significant. Although Calostropis gigantea accumulated more REEs per unit dry matter than coconut, it failed to compete effectively for REEs in mixed culture with coconut. However, in mixed culture, coconut depressed the absorption of REEs by Calostropis gigantea.

The effect of feed deprivation on gastrointestinal respiration and Na+, K+-ATPase in chicks

In order to investigate the effect of nutrient availability on energy metabolism of the gastrointestinal tract (GIT) of chicks, two experiments were conducted. In exp. 1, jejunal slices from male White Leghorn chicks at 14 d were incubated in salt-based balanced medium (SBM) or complex medium (CM) for 30 min. The total O2 (TO2) and ouabain-sensitive O2 (OSO2) consumption in jejunal slices were significantly decreased in SBM. The results from exp. 1 imply that when the GIT mucosa is subjected to nutrient deprivation, the utilization of oxygen consumption is altered primarily by shifting active Na+ pump activity. Changes in the TO2, OSO2 and amiloride-sensitive O2 (ASO2) uptake in response to feed deprivation in the small intestine of male White Leghorn chicks were investigated in exp. 2. There was little change in TO2, OSO2 and ASO2 per unit of dry matter of the small intestine from birds subjected to fasting, except for a TO2 decrease in the jejunum of 48 h fasted chicks. However, there were significant reductions in TO2, OSO2 and ASO2 in the jejunum when data were expressed per unit DNA. Na+, K+-ATPase-dependent respiration represented 31–37% of TO2 in the avian jejunoileum. Amiloride-sensitive respiration accounted for 10–18% of TO2 in the jejunoileum. The maximal amount of 3Houabain binding sites of jejunal enterocytes was significantly decreased in chicks fasted for 48 h (P &lt; 0.05). Key words: Oxygen consumption, fasting, Na+, K+-ATPase, ouabain, jejunum, ileum, chicks

A computer program to calculate the cost of providing ruminants with home-produced feedstuffs

A computer program was developed to facilitate the rapid and standardised calculation of the cost of providing home-produced feedstuffs for ruminants in Ireland. The user, most likely an advisor, researcher, specialist or consultant, is guided via a menu system through a sequence of options (for each of which defaults are provided that can easily be replaced) to choose the management, physical, biological and financial components of producing, harvesting, storing, processing and feeding various crops, as appropriate. Direct and indirect (e.g. land charge) costs, inherent efficiencies, subsidies (e.g. European Union area aid), etc. can all be taken into account. Feeds are costed per unit of dry matter (DM), digestible DM or metabolisable energy (ME) available for consumption. Among the unit costs determined were those of providing ruminants with grazed grass, individual harvests of grass silage or hay, maize silage, fodder beet roots (or whole crop silage) and wheat, barley or oats grain (or whole crop silage).

Effect of available phosphorus in paddy soils on phosphorus uptake of rice

Relation between available phosphorus in 6 types of paddy soil in, Human Province and its uptake by rices was studied by32P tracing. The result indicated that the P uptake by rices varied with available P content in the paddy soils. When the content was high, the rice absorbed more P nutrient from the soil and decreased the P uptake from the P fertilizer, which showed a poor contribution of the P fertilizer to the rice yield increase, and vice versa. The recovery of the P fertilizer varied with the soil types. Ranked the first was in paddy soils derived from lacustrine deposite but little rice yield increased. While in paddy soils derived from limestone, the yield greatly increased although the recovery of P fertilizer was the lowest. Rice absorbed P nutrient during its whole growth duration. No matter the different uptake amount due to the P supply by the different soils, rice plant generally had the greatest P nutrient uptake from tillering stage to elongation stage, and along with the rise of the rices dry matter, amount of P uptake was gradually increased but the P content in unit dry matter was tended to decrease.