bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on Calcium Cyanamide. II. Microbiological Aspects of Nitrification in Soils Under Varied Environmental Conditions (With Four Text-figures.)
Authors: Mukerji B. K. 
Published: March 2009

1. Calcium Cyanamide (the commercial form of Calcium Cyanamide) markedly increased the bacterial numbers of soils in uncropped pots and both the bacterial numbers and carbon dioxide production in flasks under laboratory conditions.2. Improvements in the aeration of soil cultures in the laboratory not only increased the numbers of bacteria and accelerated the production and disappearance of ammonia but reduced the initial nitrification lag and increased the final accumulation of nitrate from Calcium Cyanamide. Urea formed from Calcium Cyanamide disappeared much more quickly in soils aerated by daily shaking than in undisturbed soils.
Relationship between sperm concentration, initial fructose concentration and different measures of fructolysis in buffalo semen
Authors: Dhanotiya R. S. , Srivastava R. K. 
Published: March 2009

SUMMARYFI (mg of fructose utilized by 109 sperms in 60 min at 37 °C), fructolytic coefficient, Ku (fractional decline in the spermatozoal fructolytic activity per minute on an instantaneous basis) and maximum fructose utilization, MFU (mg of fructose utilized by 109 sperms in 1 min at zero incubation time on an instantaneous basis), have been estimated for buffalo spermatozoa. Out of these three attributes, the fructolytic coefficient was found to be independent of the initial fructose concentration (IFC), sperm concentration and incubation period and was a better criterion for the assessment of the quality of buffalo semen than the fructolytic index.Simple and partial correlation coefficients between sperm concentration, IFC and FI, fructolytic coefficient and maximum fructose utilization are presented.
Seasonal fleece changes in two selection lines of Scottish Blackface sheep during their lifetime on the hill
Authors: Ryder M. L. 
Published: March 2009

SUMMARYTen Scottish Blackface ewes from each of three lines, a line selected for hairiness, a line selected for a fine fleece, and an unselected control, were fleece and skin sampled in April, June, September and December, during their 6J year life-span on the hill.Fleece weight differed between individuals and between lines, and declined by 4% per year from 1·5 kg at 1 year, to 1·3 kg at 6 years. Fleece grade was inadequate as a method of denning fleece differences between the lines.The height of the spring ‘rise’ in growth in April differed between years, and between lines, declining 2 mm a year from 26 mm at 1 year. Staple length was greatest in the Hairy group and least in the Fine group (P < 0·05). Growth in length was faster between September and December (autumn) than between April and June (spring). Staple length decreased by 14 mm a year.The lines differed significantly (P < 0·05) in mean fibre diameter but not in modal fibre diameter. There was a highly significant decrease in diameter from summer to winter, ranging from 20% in the Fine line to 31% in the Hairy line, the greater decrease in the Hairy line being attributed to loss of medulla.The selection had between 1954 and 1972 changed the S/P follicle ratio of 3·0 in the control to 2·8 in the Hairy line and 3·2 in the Fine line. Most seasonal follicle inactivity occurred in April, December came second, and June invariably had more follicle inactivity than September. The control line had the greatest values of primary follicle inactivity and the Fine least. Among the secondary follicles the Hairy line had most inactivity, and the control line least. Maximum primary fibre medullation occurred in either June or September, and medullation was at a minimum in December or April.
The performance of cowpea (Vigna unguiculata (L.) Walp) as influenced by weed competition
Authors: Remison S. U. 
Published: March 2009

SummaryExperiments were made in a glasshouse and in the field to estimate the effect of weed competition on cowpea performance.In the glasshouse experiment, plant height, number of nodes, green leaves, peduncles, weight of poda and seeds of cowpea were decreased by competition from Euphorbia heterophylla and the decrease was greater with increasing density of the weed associate. Generally cowpea did not respond to application of fertilizers. In the field experiment, competition from the natural weed flora affected the number of days to 50% flowering and yield components of the four cowpea varieties studied. The yield of the climbing variety, Dinner, was least affected by competition whilst the semi-erect variety, Ife brown, was the most affected.
The phosphorus requirement of lettuce: II. A dynamic model of phosphorus uptake and growth
Authors: Scaife M. A. , Smith R. 
Published: March 2009

SummaryA dynamic model is presented in which the problem of predicting P response is broken down into various components, such as:(a) Weight and P content of emerging seedling.(b) Normal growth curve of the fully nourished plant.(c) A ‘deficiency-tolerance’ factor relating depression of relative growth rate to plant P concentration.(d) An ‘affinity’ term relating sink concentration to P status of plant.(e) A perirhizal resistance term for diffusive transport to roots.(f) Capacity and intensity of P supply from the soil. Mass flow supply via the transpiration stream is also included.By changing parameter values one may attempt to simulate the effect of any of these factors on the shape of the P response curve and any other part of the system throughout crop life. At present the model over-estimates growth at low levels of P supply, but predicted plant P concentrations agree reasonably well with observed data.
The free- and protein-amino acids of the rumen phycomycete fungi Neocallimastix frontalis and Piromonas communis
Authors: Kemp P. , Jordan D. J. , Orpin C. G. 
Published: March 2009

SUMMARYThe proteins and the amino acid profile of the rumen fungi Neocallimastix frontalis and Piromonas communis have been examined and the in vitro digestibility of the vegetative growth determined.The mean true protein content of N. frontalis was 24% of the dry weight and 30% for P. communis, which has a lower chitin content. 50% of the protein extracted from cells and examined by HPLC was in the 200000 MW range and 40% in the 50000 MW range. Polyacrylamide gel electrophoresis after treatment with sodium dodecylsulphate and 2-mercaptoethanol indicated that the native proteins were composed of smaller units in the MW range 25000–50000.The amino acid profiles of the two fungi were similar and compared favourably with those of casein and fraction 1 protein of lucerne.
Enhanced soil temperature during very early growth and its association with maize development and yield in the Highlands of Kenya
Authors: Cooper P. J. M. , Law R. 
Published: March 2009

SummaryPrevious work has shown a strong relationship between the mean soil temperature during the first 5 weeks of growth of a maize crop, and the final grain yield, warmer soils leading to greater yields. Trials were laid down in 1975 and 1976 to establish how early in the development of a maize crop higher soil temperatures would lead to increased yields. Soil temperatures were raised by polythene mulching applied at planting with six times of mulch removal: at crop emergence, 1, 2, 3, 4 and 5 weeks after emergence. Raised soil temperature led to a greater rate of development and leaf area production during early growth. Greater leaf area was due to greater leaf emergence rate rather than increase in leaf size, since increase in soil temperature was associated with a decrease in individual leaf size. This trend was reversed from leaf number 15 onwards resulting in no differences in leaf area, leaf weight or total dry matter at tasselling. In spite of this, yield differences were observed. Increase in soil temperature during germination alone had a beneficial effect on final grain yield, and this effect increased with duration. Increasing soil temperature for longer than 3–4 weeks from emergence caused no further yield increase. Yields increased from 133 and 172 g/ plant to 220 and 238 g/plant in 1975 and 1976 respectively. Yield increases were associated with more grains per plant rather than greater grain size. The period during which increased soil temperature led to increased yields coincided with the period when the apical meristem was below ground level. The mechanism involved is not yet clear.
Changes in major element composition of developing barley grain
Authors: Duffus Carol M. , Rosie Roberta 
Published: March 2009

SummaryChanges in the amounts of nitrogen, phosphorus, magnesium, calcium and sodium present in intact grain, endosperm, testa pericarp and embryo throughout the developmental period were recorded. While the overall pattern in intact grain was one of steady accumulation, considerable variation from this pattern was found within the different parts. The results are discussed in relation to the biochemical events accompanying maturation.
Thin sows: 2. Observations on the energy and nitrogen exchanges of thin and normal sows in environmental temperatures of 20 and 5 °C
Authors: DeB. Hovell F. D. , Gordon J. G. , MacPherson R. M. 
Published: March 2009

SummaryThe experimental animals were sows which had been made thin by underfeeding for several parities (thin sows), and siblings which had received adequate energy (standard sows).The energy metabolism of three thin anoestrous and three non-pregnant standard sows were measured at 20 and 5 °C. There were no differences between the two groups of sows. The fall in temperature increased the average maintenance requirement by 60% from 476 to 753 kJ/kg0·75/day (1192–1922 kJ/kg0·56/day).The tissue insulation of the thin sows was 28% lower than that of the standard sows, although this difference was not statistically significant. The thin sows compensated by having a better external insulation. The average total body conductance was 306 kJ/m2/°C/day.The standard sows were in positive nitrogen balance (+ 4·2 g/day, 95% confidence limits 1·5 to 7·0 gN) and the thin sows in negative nitrogen balance (– 4·4 g/day, 95% confidence limits – 2·1 to – 6·8 g N) at energy equilibrium. It is suggested that this difference might be explained if the total nitrogen requirement of the two groups of sows was similar, but that their requirement for energy was related to their body surface area.There were no differences between the two groups of sows in their digestive efficiency, but the digestibilities of both energy and nitrogen were reduced at 5 °C.It is concluded that the primary cause of the ‘thin sow syndrome’ is underfeeding, particularly in cold environments. Other features of the syndrome are probably a consequence of undernutrition and depletion of the body energy reserves.
A histological technique, using cellulolytic enzyme digestion, for assessing nutritive quality differences in grasses
Authors: Selim O. I. , Wilson D. , Jones D. I. H. 
Published: March 2009

SUMMARYTransverse sections of Festuca arundinacea Schreb. leaves were incubated in cellulase at 40 °C with and without pepsin pretreatment. The sequence of tissue breakdown (mesophyll-phloem-adaxial epidermis) was the same in both treatments, but the rate of breakdown was much slower without pepsin pretreatment (up to 30 h compared with up to 90 min). Pepsin appeared to make the primary cell wall more susceptible to cellulase attack. Young leaves were digested faster than old. Possible applications to the evaluation of grass nutritive quality are discussed.
Nitrogen response curves of spring barley
Authors: Sparrow P. E. 
Published: March 2009

SummaryThe results of 83 experiments with nine levels of nitrogen and six experiments with seven levels were used to investigate models of the response of spring barley to nitrogen. Of the eight models tested, the inverse quadratic, Greenwood's modification of the inverse linear and two intersecting straight lines represented the yield/fertilizer relationship well, although no one model fitted best at every site.The three models differed little in their average predicted optimal yields, but a slightly smaller average optimal dressing was predicted from two straight lines.
The effect of field drying on the concentrations of some major elements in herbage
Authors: Wilman D. , Mzamane Nthoana 
Published: March 2009

SUMMARYHerbage from a grass-white clover sward was dried in the field to the hay stage (≤ 0·33 g moisture/g dry matter) at three times of year in 2 years comparing, in each case, all combinations of two stages of maturity, two levels of applied nitrogen and two thicknesses of swath. Samples taken at intervals during drying were analysed for nitrogen, phosphorus, potassium, calcium, magnesium and sodium.When there was little or no rain during drying, there was no change in the concentration of any of the six elements in the herbage dry matter between cutting and the hay stage, whatever the stage of maturity, level of N applied or swath thickness.The concentrations of potassium and sodium in the crop were greatly reduced by rain in the later stages of drying, but were less affected by rain in the early and middle stages; the concentrations of calcium and magnesium appeared to be reduced by rain as readily in the middle as in the later stages; the concentrations of nitrogen and phosphorus were relatively little affected by rain, but seemed likely to be more at risk in the later stages. The extent of the reductions in the concentration of elements was not markedly affected by the stage of maturity or level of N applied. There were reductions in the thin but not in the thick swaths when rain fell during the early and middle stages of drying, probably partly or wholly because the herbage in the thin swaths was drier, with a higher proportion of dead cells, at that time than the herbage in the thick swaths. At least 70 kg K/ha was leached out of the crop in the thick swaths by rain in the late stages of drying.
Evaluation of lentil harvest systems for different sowing methods and cultivars in Syria
Authors: Erskine W. , Diekmann J. , Jegatheeswaran P. , Salkini A. , Saxena M. C. , Ghanaim A. , Ashkar F. El 
Published: March 2009

SUMMARYHand harvesting is a major constraint to lentil production in North Africa and West Asia. This study, in north Syria, compared hand harvesting, cutting by mower (double-knife) and cutting with angled blades on two lentil cultivars differing in standing ability and using two sowing methods (broadcast and drilled) both with and without the use of a heavy bar for field levelling in the 1984/85 season. Seven treatments were selected for testing in five locations in the 1985/86 season; and in the 1986/87 and 1987/88 seasons, agronomic comparisons of mowing v. hand harvesting were conducted on five farmers' fields.Both machine methods of harvesting resulted in significant harvest losses compared with hand harvesting. The angled blades performed well on a ridged broadcast crop, but tended to mix soil with the harvested crop. The loss of straw associated with harvesting by mower was reduced by levelling the seedbed after sowing. The superiority in seed yield of cultivar 78S26002 over the local cultivar increased from 9% when hand harvested to 39% with mowing because of its lower likelihood of lodging. In the 1986/87 and 1987/88 seasons, the seed yield from a hand harvest was 1650 kg/ha compared with 1508 kg/ha following harvest by mower, representing a loss of 8·6% from mechanization. The corresponding straw loss was 16·6% of the mean from a hand harvest of 2140 kg straw/ha. However, the harvest losses from mechanical harvesting by mower were compensated for by the reduced labour costs compared with hand harvesting.
Nitrogen nutrition of wheat following different crops
Authors: Echeverría H. E. , Navarro C. A. , Andrade F. H. 
Published: March 2009

SUMMARYA trial using a split-plot with blocks design was carried out at the INTA Balcarce Experimental Station, Argentina on a typic argiudol soil to evaluate N nutrition in wheat after different preceding crops and using two rates of N fertilization (0 and 90 kg N/ha).Wheat (Triticum aestivum), soyabean (Glycine max), sunflower (Helianthus annuus) and maize (Zea mays) were grown in different combinations for two successive years (1984/85 and 1985/86).No water stress was detected during either growing season. Nitrogen availability was altered by the previous crops grown, but the effect lasted only for one season. Wheat following maize yielded least with no N and responded most to N fertilization. The highest yields of wheat without N and the lowest response by wheat to N fertilization were found after crops of soyabean and sunflower.Wheat after a fertilized wheat crop did not respond to N fertilization because of a serious attack of take-all (Gaeumannomyces graminis tritici).The nitrate concentration in wheat stem bases was found to be a good estimator of the availability of soil N.
Influence of variety, row type and time of sowing on the morphology, chemical composition and in vitro digestibility of barley straw
Authors: Capper B. S. , Sage G. , Hanson P. R. , Adamson A. H. 
Published: March 2009

SUMMARYLeaf proportions (LP) were determined in spring barley straws harvested at Cambridge in 1984 and 1985. Linear regression equations showed that a greater number of days to flowering increased LP whilst greater plant height decreased LP in spring barley straws. Plant height accounted for more than 70% of the variance in LP. By contrast, grain yield and stem diameter accounted for only a small percentage of the variance in LP. Straws from two-rowed winter barleys had slightly higher LP than six-rowed winter barleys but LP in winter and spring barleys were similar.Leaf blade and leaf sheath fractions of the straws had lower acid detergent fibre and lignin contents and were more digestible than the stem fractions. Linear regression equations of straw digestibility in spring barleys on LP, grain yields, days to flowering and plant heights showed that LP accounted for a higher percentage of the variance in digestibility in 1984 than the other characteristics. In 1985, when harvesting conditions were unusually wet, grain yield accounted for the highest percentage of the variance in straw digestibility.There were no differences in chemical composition and straw digestibility between two-rowed and six-rowed barleys, but winter barleys had higher straw digestibility than spring barleys. Date of sowing did not influence straw quality in two-rowed winter barleys.The ranking of two-rowed spring barleys for LP, chemical composition and digestibility suggested that varieties with consistently better straw quality could be identified.
Effect of ruminal infusion of acetic acid and sodium acetate on the concentrations of ciliate protozoa
Authors: Borhami B. E. A. , El-Shazly K. , Akkada A. R. Abou 
Published: March 2009

SUMMARYTwo fistulated rams were infused through the rumen cannulae with acetic acid or sodium acetate for 4 consecutive days. This infusion has caused a significant drop in the daily feed intake and in the concentrations of rumen ciliate protozoa. The holotrich protozoa were the most susceptible, whereas entodinia were the least sensitive, to the reducing effect of acetic acid or sodium acetate. Decreasing the daily feed intake by 30% has caused little or no change in the concentrations of rumen ciliate protozoa. The in vitro incubation of sodium acetate and rumen contents has resulted in a remarkable depression in the protozoal numbers. Most of this decrease occurred after 5 h of incubation. The addition of acetic acid or sodium acetate to washed suspensions of mixed populations of rumen ciliate protozoa has decreased the in vitro volatile fatty acid production. It is suggested that both the low pH and acetate, ion were responsible for the reduction in the protozoal numbers in the rumen of rams infused with acetic acid or sodium acetate. The effect of acetate on the ciliate protozoa could be an explanation of the diurnal changes in the concentrations of various protozoal groups usually observed in the rumen of the host animal.
The artificial rearing of calves and their growth on grass diets:III. The effect of length of period of feeding cold milk Substitute to calves given dride grass in different physical forms
Authors: Lonsdale C. R. , Tayler J. C. 
Published: March 2009

SUMMARYAn experiment was conducted with 63 July-born Friesian heifer calves, purchased at an average age of 10 days and fed cold reconstituted milk substitute for 4, 6 or 8 weeks. The sole ‘solid’ feed was dried grass, chopped and fed loose (a), milled through a 6 mm screen and pelleted (b) or milled through a 3 mm screen and pelleted (c). The experiment was of 3 x 3 factorial design.Calves fed milk for 4, 6 or 8 weeks consumed mean amounts of 20, 42 and 63 kg milk D.M. respectively. During the first 10 weeks the mean daily intake of grass b was significantly greater than that of grasses a or c (0.77, 1.09 and 0.89 kg D.M. for grasses a, b and c respectively) and during weeks 11 to 21 the mean intake of grasses b and c was greater than that of a (3.1, 4.1, 3.7 kg D.M. for grasses a, b and c respectively). Also during weeks 11 to 21 the previous milk feeding had a small but significant effect on the mean daily intake of grass (3.4, 3.7, 3.8 kg D.M./head/day for 4, 6 and 8 weeks of milk feeding respectively).Increasing the period of milk feeding significantly increased the rate of live-weight gain during the first 10 weeks, but subsequently had no effect. During the first 10 weeks and during weeks 11–21, feeding grass b or c significantly increased the rate of liveweight gain compared with grass a but had no effect during a period of uniform feeding, weeks 23–34.During the first 21 weeks feed conversion efficiency was positively related to duration of milk feeding, and was greater for calves given grass b or c than, for thoso given grass a.During weeks 23–34, 36 calves (4 from each original treatment) were fed another uniformly milled and pelleted dried grass. There were no significant differences in voluntary intake, live-weight gain or efficiency of food conversion between the groups of calves during this period. Hence the results of this experiment support previous observations, that when only forage diets are fed the effect of level of early nutrition is still evident in live weights of calves at 6 months of age.
Phosphorus and calcium metabolism in growing calves with special emphasis on phosphorus homoeostasis. 4. Studies on milk-fed calves given different amounts of dietary phosphorus but a constant intake of calcium
Authors: Challa J. , Braithwaite G. D. 
Published: March 2009

SUMMARYFriesian bull calves, 2 weeks old, were given an experimental diet of cow's milk supplemented with phosphorus to provide three rates of P intake: adequate, high, and very high. After 1 week's preliminary feeding, studies of absorption, endogenous secretion, urinary excretion, serum concentration, retention and kinetics of Ca and P metabolism were made by a balance and dualradioisotope technique with 32P and 45Ca.The efficiency of P absorption decreased significantly as the P intake increased and the highest absorption efficiency was 96% on the unsupplemented milk diet. Endogenous faecal excretion of P was low on all treatments. Urinary P excretion was substantial even on the milk-only diet and increased further with supplementation of P. The efficiency of absorption of Ca remained constant, and urinary Ca excretion was low in all the groups. Serum P and Ca concentrations did not vary significantly but there was a significant decrease in the retention of P and Ca as the P intake increased.Although urinary excretion appears to be the main process responsible for P homoeostasis in preruminant milk-fed calves, some regulation of the efficiency of absorption of P according to the P intake may also occur.