bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of different concentrations of atmospheric CO2on growth and yield components of wheat
Authors: Sionit N. , Strain B. R. , Hellmers H. 
Published: March 2009

SummaryGrowth and yield components of a semi-dwarf spring wheat (Triticum aestivumL., cv. GWO 1809) were determined under three different atmospheric CO2a concentrations (350, 675 and 1000 μ1/1) in controlled environment chambers of the Duke University Phytotron. CO2 enrichment enhanced tiller and head emergence and increased the number of head-producing tillers and the total dry weight of the plants. Total leaf area, stem height and root/shoot ratio of the plants were greater at high CO2concentrations than at low. Net assimilation rate (NAR) increased with increasing CO2concentration and decreased with plant size. There was little effect of CO2enrichment on leaf weight ratio (LWR) and leaf area ratio (LAR) and no significant effect on specific leaf area (SLA). The weight and number of seeds were significantly higher with increasing CO2concentration. The results of this study provide evidence that important changes in plant growth and development may occur during the next century if global CO2enrichment continues. Some of these changes would have important ecological impact in natural and managed ecosystems in the future.
Factors affecting body weight and growth rate of Awassi lambs
Authors: Bhat P. N. , Koul G. L. , Koul S. K. , Kumar R. , Garg R. C. 
Published: March 2009

SummaryAn experiment was carried out to study the effect of early weaning on body weight and growth rate of Awassi lambs raised at Abu-Ghurib Experiment Station, Baghdad, Iraq. Sex, type of birth and weaning age significantly influenced the body weight and growth rate of lambs at all the ages studied. Dam's age and weight at lambing, however, did not affect the growth rate of the lambs. The average body weights of lambs at 4 and 6 months of age were 23·8±0·28 and 32·3 ± 0·36 kg. The average daily gain in weight up to 120 and 180 days of age was 162·3 ±2·57 and 153·7 ±1·94 g/day respectively. Males were heavier than females and singles were heavier than twins at all the ages. Lambs weaned at 60 days of age were heavier and had a faster growth rate than those weaned at 90 or 120 days of age. Males born to 2-year-old dams grew fastest while the females born to them had the lowest body weights and growth rate.
Use of a cellulolytic enzyme digestion technique to distinguish bloat-causing from non-bloat-causing legumes and to select for speed of mesophyll cell-wall disintegration in red clover (Trifolium pratense L.)
Authors: Sant F. I. , Wilson D. 
Published: March 2009

SUMMARYCell walls of three bloat-causing legumes, lucerne, red clover and white clover tended to be thinner and disintegrated significantly (P < 0·05) faster during cellulase digestion than those of two non-bloat-causing legumes, sainfoin (reported to contain tannins) and cicer milkvetch (reported not to contain tannins). Response to one generation of selection for speed of mesophyll cell-wall disintegration was marked in a diploid red clover (h2 = 0·66, 1·13) but slight in a tetraploid (h2 = 0·10, 0·13).
Absorption of glucose by lamb proximal colon measured during early postnatal development
Authors: Smith M. W. , James P. S. 
Published: March 2009

SUMMARYPieces of proximal colon taken from lambs during the first 2 weeks of postnatal life were incubated in vitro for measurement of short-circuit current and unidirectional glucose fluxes.The short-circuit current of colons taken from newborn and 1-day-old lambs was increased significantly in the presence of 5 mM D-glucose. This is taken as evidence for the presence of an active transport system for monosaccharides in this tissue. No such effect was seen using colons taken from 2-week-old lambs.Direct measurement of glucose transport showed a net absorption to take place across the proximal colon of newborn and 1-day-old lambs. There was no net movement across colons taken from lambs aged 1 week and over. Essentially similar results were obtained when measuring the amount of glucose influx inhibited by 10−5 M phloridzin.Colonic decline of glucose transport follows a time course different from that reported previously for the small intestine. It probably arises from rapid maturation of the colonic mucosa postnatally rather than from any gradual absence of substrate occurring during rumen development.
Utility of Rhizobium in the phyllosphere of crop plants in nitrogen-free sand culture
Authors: Nandi A. S. , Sengupta B. , Sen S. P. 
Published: March 2009

SUMMARYSoya bean, mung bean, Bengal gram and lentil grown in nitrogenless sand culture and sprayed with suspensions of different strains ofRhizobiumshowed increases in dry weight, chlorophyll and N-content. In a few cases the performance ofRhizobiumapplied to the phyllosphere was almost as good as a seed inoculation treatment. The beneficial effect of sprayingRhizobiumstrains was independent of the specificity of cross-inoculation groups. Nitrogenase activity as indicated by acetylene reduction by theRhizooium-leafassociation varied between 460 and 723 nmol/g leaf/h.
Investigations into the role of specific micro-organisms in the aerobic deterioration of maize silage
Authors: Woolford M. K. , Wilkie Ann C. 
Published: March 2009

SummaryTwo experiments were undertaken with maize silage, which had been sterilized by subjecting it to a 6 Mrad dose of γ radiation, inoculated with micro-organisms implicated in the aerobic deterioration of silage and subsequently exposed to air. The inocula employed comprised mixed strains of yeasts, bacilli and lactic acid bacteria and combinations of these. The changes which accompanied aerobic deterioration were observed. The major losses of fermentation acids, ethanol, ammonia and dry matter, and increases in total nitrogen and temperature were associated with inocula in which yeasts were represented. Similar changes of a lower magnitude were also observed in silage treated with inocula containing bacteria only, although these were not always accompanied by the growth of these organisms or loss of dry matter. However, when employed in mixed inocula with yeasts, the bacteria proliferated and tended in some instances to increase losses further, suggesting an association between the groups of micro-organisms in the aerobic deterioration process. Losses were also sustained in sterile silage which received no inoculum and the possible reasons for this are discussed.
The role of foliar fertilizers in tolerance of the cotton leafworm to certain insecticides
Authors: Moustafa Omayma K. , El Attal Z. M. , Doban Amal F. 
Published: March 2009

SummaryEvaluation of some insecticides against nine strains of S. littoralis, selected with decamethrin and foliar fertilizers separately and their combinations for three successive generations, was conducted to elucidate the effects of fertilizers on the tolerance pattern. The results indicate that the selection with fertilizers induced a low level of tolerance to both cyolane and profenofos. The LC50 of chlorpyrifos for all fertilizers' strains was lower than that of the susceptible strain. The efficiency of cyolane and fenvalerate on strains developed by the selection with decamethrin-fertilizer combinations was remarkably increased. Since the selection with fertilizers has induced a tolerance to some insecticides such as cyolane and profenofos and as the efficiency of these insecticides was enhanced on strains developed by the pressure of decamethrinfertilizer combinations, it is preferable to use decamethrin simultaneously in admixture with foliar fertilizers for pest control.
The lactation performance of red deer on hill and improved species pastures
Authors: Loudon A. S. I. , Darroch A. D. , Milne J. A. 
Published: March 2009

SummaryThree groups of red deer hinds of 9–10 years of age were grazed upon an indigenous hill pasture (A), an improved species grass sward (predominantly perennial ryegrass) maintained at < 1500 kg D.M./ha (B), and one maintained at 2000 kg D.M./ha (C) from immediately after calving on 29 May until weaning on 22 September. Numbers of hinds in each treatment were 8, 6 and 9 respectively. Milk yields of hinds were estimated on swards A and C by the calf-suckling technique and hind and calf live-weight changes and hind grazing behaviour were recorded on all three swards during lactation.Hinds on award C yielded on average 60% more milk over the lactation period than hinds on sward A, day 40 yields being 2·2 and 1·5 kg/day respectively. Calf growth rates (treatment A, 257 ± 9·5, B, 324 ± 12·1 and C, 369 ± 14·5 g/day) were higher on the improved species sward than on the hill sward and higher on the improved sward with the greater herbage mass. On treatments A and C calf growth rates were significantly (P < 0·05, r = 0·69) correlated with milk yield throughout lactation. At weaning, calves on sward C were 7·5 and 4·5 kg heavier than those on swards A and B respectively. Biting rates were lower (33 v. 56 bites/min) and grazing times higher (11.7 v. 6.0 h) on sward A than swards B and C. The poorer performance of hinds and their calves on sward A was considered to be due to a lower quality of diet ingested, and to behavioural limitations on intake occurring when hinds graze indigenous swards of relatively high species diversity. These results are discussed in relation to the grazing behaviour of cattle and sheep on similar swards.The significance of the results to red deer farming in the U.K. is briefly discussed.
Tillage under controlled conditions: its effect on emergence and yield of spring barley
Authors: Brown N. J. , North P. F. 
Published: March 2009

SummaryEffects of controlled tillage and soil-water conditions at the time of cultivation on emergence and grain yield were measured for a spring barley crop grown on a silty clay loam soil. A range of soil densities was achieved using conventional implements (tine-cultivator and roller) in combination with three levels of soil wetness. Concrete tracks supported both tractor and implements to prevent compaction due to wheelings, and rain-activated mobile shelters excluded precipitation from the field site.Tillage treatments had large and significant effects on plant establishment. Both rate of emergence and final emergence were lowest where the soil was rolled at a high moisture content, and greatest where it was cultivated dry. Time for 50% plant emergence, rate of emergence and final plant population density all tended to be linearly correlated with the bulk density of the prepared seed bed. Despite large differences in plant establishment, later compensatory growth caused final yields of grain to show no significant response to tillage treatment.
Metabbolism of perfused ruminant muscle
Authors: Coward B. Jane , Buttery P. J. 
Published: March 2009

SUMMARYSubstrate and nitrogen metabolism of ruminant muscle was studiedin vitrousing a perfused sheep hemidiaphragm preparation. Glucose, acetate, propionate and butyrate were taken up by the perfused muscle at a constant rate over 2 h. Rate of acetoacetate uptake declined over the perfusion period. Net production of 3-hydroxybutyrate over the perfusion period was observed.Release of alanine and glycine by the perfused muscle could not be accounted for by protein breakdown, implicating muscle as a site of synthesis of these amino acids. The perfused muscle metabolized aspartate and arginine to a considerable extent, but the branched-chain amino acids only to a small extent. Only a small proportion, approximately 5%, of the alanine produced by the perfused muscle was derived from glucose.In the presence of amino acids, at twice the concentration found in plasma, and insulin, some amino acids showed a net uptake by the diaphragm but when cysteine was omitted from the perfusate, all amino acids with the exception of arginine showed a net output. Evidence was obtained that protein synthesis was reduced in the absence of cysteine. The output of Nτ methylhistidine by the preparation was much higher than could be accounted for by estimates of protein breakdown using isotope dilution techniques. These data are, however, consistent with the view that Nτ methylhistidine is not a good index of muscle protein breakdown in sheep.
Effect of root zone temperature on early growth, nodulation and nitrogen fixation in soya beans
Authors: Matthews D. J. , Hayes P. 
Published: March 2009

SUMMARYSoya-bean plants were grown for 40 days in a range of root temperatures from 10 to 25°C either in a root medium containing N but uninoculated or in a N-free medium but inoculated withRhizobium japonicum. Low root temperature restricted growth in both cases but the plants depending solely on symbiotic N-fixation were much more affected. At 10 CC root temperature plants failed to nodulate but both nodulation and nitrogen fixation increased greatly in the range 15–25°C. It is concluded that soya beans sown in cool soils would benefit from applied nitrogen at sowing time.
Towards more efficient soil-water modelling: moisture profiles for constant application or removal of water at the surface
Authors: Towner G. D. 
Published: March 2009

SUMMARYSoil-water profiles are often calculated using models based on the application to successive soil layers of an approximate formulation of Darcy's Law. An arbitrary decision is usually made concerning the magnitude of the layer thickness, Δz, and time increment Δt, a decision often based on the intuitive criterion that both should be as small as possible. An unsuitable choice can either give rise to oscillations in the solutions that can be eliminated only by recalculation using different increments, or can culminate in an accuracy unjustified by the precision of the data, both cases resulting in unnecessarily lengthy and wasteful computing. However, mathematicians have shown, for problems which are analogous to particular soil-water models, that oscillations will not occur if τ = D(Δt)/(Δz)2 ≥ 0·50 (where D is the soil-water diffusion coefficient, assumed constant).This paper considers the development of moisture profiles in soils with a constant rate of loss (e.g. evaporation) or entry (e.g. irrigation) of water imposed at the surface, and demonstrates that the criterion τ ≥ 0·50 can be extended to apply to waterdependent diffusion coefficients by re-interpreting D as the maximum value occurring in the profile. Examples for 10-layer models suggest that it is sufficient for practical purposes to start with Δt values that give τ-values close to 0·50, and to proceed to smaller Δt-values only when necessary. The total gain or loss of water given by integrating the calculated profiles is compared with the known amount entering or leaving at the surface.The profiles for both evaporation and irrigation are found to advance too rapidly.
Effect of pasture growth rate on live-weight gain of grazing beef cattle
Authors: Ebersohn J. P. , Moir K. W. 
Published: March 2009

SummaryLive-weight gain of beef cattle grazing all-grass or grass-clover pastures, details of which have been reported previously, was significantly (P < 0·01) correlated with pasture growth rate, but not with pasture dry matter on offer (either total or green), or with dietary-energy concentration. From ideas generated from the relationship between live-weight gain and pasture growth rate, and using intake values measured from the number and size of prehension bites, it is shown how high live-weight gain for measured dietary-energy concentration could be explained by differential contribution to digestibility and voluntary intake from pasture new growth.
Histochemical localization of enzymes of various metabolic pathways in the testes of buffaloes, goats and rams
Authors: Bilaspuri G. S. , Guraya S. S. 
Published: March 2009

SummaryIsocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), β-hydroxybutyrate dehydrogenase (β-OH-BDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) were histochemically located in the testes of buffaloes, goats and rams. The enzyme activities varied with the enzyme, species and cell type. The activities in the seminiferous tubules were correlated with the stages of seminiferous epithelial cycle (SEC). During this cycle, the activities in the Sertoli cells, spermatogonia and spermatocytes remained unaltered in contrast to those in the spermatids. The activities of SDH, ICDH and MDH were relatively greater in buffalo, while goat and ram resembled each other quite closely. ICDH and MDH preferred NADP to NAD. In the three species, the activities of ICDH, SDH and MDH generally followed an increasing order. G-6-PDH was greater in the interstitial tissue of buffalo than in goat and ram; the maximum activity of this enzyme in each species was found in the spermatogonia. In comparison with G-6-PDH, GDH was less evident in the interstitial tissue of buffalo and goat; Sertoli cells and spermatogonia also showed relatively less MDH activity whereas the other germ cells may have relatively less, similar or more, GDH activity depending on the species. β-OHBDH activity was similar in the interstitial tissue of the three species, but in the seminiferous tubule, the activity was less in goat. But for GDH and β-OH-BDH which could show different results, the activities of other enzymes generally decreased from spermatogonia through spermatocytes to spermatids but increased during spermiogenesis. In spermatozoa, the enzymes were observed only in the mid-piece. The possible physiological significance of the results is discussed in relation to different metabolic pathways.
Some observations on phosphorus homoeostasis and requirements of sheep
Authors: Braithwaite G. D. 
Published: March 2009

SummaryThe results of phosphorus kinetic studies from 149 sheep used in previous studies of calcium and P metabolism have been analysed statistically, to provide information on the mechanism of control of P homoeostasis.Whereas the rate of absorption of dietary P was increased in direct relation to P intake, the efficiency of absorption was decreased. Both the rate and efficiency of absorption, however, were increased in response to increased P demands. These results suggest that P may be absorbed by two processes: a passive one, related to P intake, and an active one, related to P demands.Endogenous loss of P in the faeces was directly related to both P intake and P absorption but inversely related to P demands. Salivary secretion of P was directly related to P absorption and increased at a rate of 1 mg/day/kg body weight for each 1 mg/day/kg body weight increase in absorption. This finding supports the suggestion that the inevitable endogenous faecal loss of P, in animals fed exactly according to their P requirements, is not constant but varies in direct relation to the rate of P absorption, and hence to the P intake needed to supply these requirements.Urinary loss of P was generally low, but high values were found in some animals and were associated with increased rates of P absorption and decreased rates of endogenous faecal loss of P. Possible reasons for these high rates of urinary P are discussed.Increased P demands were met by a combination of an increase in P absorption and a decrease in endogenous faecal loss of P, and P retention was directly related to Ca retention.The relevance of these results to the calculation of P requirements and to the control of P homoeostasis is discussed.
Effect of weight change on the performance of autumn-calving suckler cows
Authors: Chestnutt D. M. B. 
Published: March 2009

SummaryOver a period of 3 years 18 autumn-calving, single suckled, April-weaned cows were stocked at three rates at pasture to gain 132, 70 or 25 kg (H, M and L respectively) between April and August and fed to lose 100, 54 or – 13 kg (H, M and L respectively) while housed between November and April, the relative total energy intake over winter being 0·64, 0·83 and 1·00 respectively. Milk yield was reduced by 2·68 kg/day on the H and 1·25 kg/day on the M treatment and as a result calves gained 37 and 10 kg less respectively over winter than on the L treatment. However, despite poorer calf performance economic considerations would indicate a preference for high weight gain during the grazing season and a corresponding loss over winter.
The effect of application of nitrogen fertilizer on the growth of opium poppy in north central India
Authors: Yadav R. L. , Mohan R. , Singh R. , Verma R. K. 
Published: March 2009

SummaryIn a 2-year field study conducted at Lucknow (26·5° N, 80·5° E and 120 m altitude), plant height, leaf area index, dry-matter accumulation and N uptake of opium poppy (Papaver somniferum L.) followed a sigmoid path. After attaining a peak of accumulation at 120 days, dry matter declined in plots given N fertilizer but remained static in the control. N application (50, 100, 150 and 200 kg/ha) increased the opium, seed and morphine yields compared with the control. Morphine concentration (%) in the opium, however, increased up to 100 kg N/ha and decreased when N doses exceeded that level. Divided application of N, i.e. half at sowing and remainder at the stem elongation stage, proved beneficial for opium, seed and morphine yields.
The selenium concentration of cereal grain and conserved and fresh herbage from farms in England and Wales
Authors: Heys Vivienne , Hill R. 
Published: March 2009

SummaryThe selenium concentration of cereal grain and herbage from 131 farms in England and Wales was, in general, low: the proportions of samples with values below 0·03 mg/kg D.M. were 60% for grain (primarily barley, from 96 farms) and 39% for conserved herbage (primarily hay, from 131 farms). Values for fresh herbage from 12 farms were similar to those for conserved herbage. There were no significant differences in selenium concentration among herbage species. For all samples, those from the Cambridge area contained more selenium than those from other parts of England and Wales.
Dormancy responses to post-harvest application of growth regulators inDioscoreaspecies: I. Responses of bulbils, tubers and tuber pieces of threeDioscoreaspecies
Authors: Wickham Lynda D. , Passam H. C. , Wilson L. A. 
Published: March 2009

SummaryThe effects on dormancy of post-harvest application of growth regulators to bulbils, tubers and tuber pieces of tropicalDioscoreaspecies were examined. Abscisic acid, kinetin, indole acetic acid and 2-chloroethyltrimethylammonium chloride were found to have little or no effect on either shoot or tuber-root production, while ethrel greatly promoted tuber-root production with little or no effect on shoot development. The germination of slices of tubers ofD. alatawas delayed by maleic hydrazide but there was no effect on intact tubers ofD. alataandD. esculenta. Treatment with 2,4-dichlorophenoxyacetic acid caused massive root and callus development along with delay in shoot development, while gibberellic acid occasioned marked extensions in the dormant period.