bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supplements to correct oxalate-induced negative calcium and phosphorus balances in horses fed tropical grass hays
Authors: Gartner R. J. W. , Blaney B. J. , McKenzie R. A. 
Published: March 2009

SUMMARYA series of experiments investigated mineral supplements for the correction of negative calcium and phosphorus balances in horses fed tropical grass hays containing more than 0·5% total oxalate.A daily supplement of a soluble calcium source was retained with an efficiency of 60% implying no interference with calcium absorption from supplements by oxalate or other factors in the hays.The palatability of limestone, rock phosphate, dicalcium phosphate, a limestone and dicalcium phosphate mixture and mono-ammonium phosphate was tested with a view to providing a supplement once weekly. With the exception of the latter, all were consumed readily when mixed with 50–60 % molasses (w/w) and hourly intakes of 200 g calcium and 50 g phosphorus were recorded.In balance trials using horses fed tropical grass hays, 1 kg of either rock phosphate, or a mixture of limestone and dicalcium phosphate (1:2, w/w), each mixed with 1·5 kg molasses, was fed on the 8th day of a 14-day balance trial. The retention of calcium from the supplements ranged from 19 to 41% and that of phosphorus from 22 to 42%. The passage time for unabsorbed minerals was about 4 days. This amount of supplementation can accommodate calcium and phosphorus losses of at least 20 and 10 mg/kg live weight/day respectively. A supplement of 1 kg limestone overcame a negative calcium balance of 20 mg/kg live weight/day but did not overcome a negative phosphorus balance.
Yield and yield components of wheat (Triticum aestivum L.) and their interrelationships as influenced by nitrogen and seed rate in the Sudan
Authors: Osman A. M. , Mahmoud Z. M. 
Published: March 2009

SUMMARYField experiments were conducted for three seasons, 1971–2, 1972–3 and 1973–4 to study the effects of nitrogen fertilizer and seed rate and their interactions on grain yield and its components and attributes of growth of two wheat varieties, Giza 155 and Mexipak. The semi-dwarf Mexipak was found to be more responsive to nitrogen application than the taller Giza 155 in a number of aspects, namely, grain yield per unit area of land, the number and weight of grains per ear, the dry weight per ear and dry weight of ears/m2. The numbers of spikelets and grains per ear of both varieties decreased linearly with an increase in seed rate. The 1000-grain weight was not affected in both varieties by either seed rate or N fertilizer.Variety × nitrogen, variety × seed rate and nitrogen × seed rate interactions were significant; the variety × nitrogen × seed rate interactions were not significant. Mexipak was found to have a definite optimum seed rate of 192 kg/ha at an optimum N level of 129kgN/ha for maximum grain yield. Giza 155 was less responsive to changes in seed rate and therefore its optimum seed rate was not as definite as that for Mexipak. Evidence presented here suggests that wheat varieties of different growth habits grown in the Sudan should receive differential treatments when the policies of setting optimum seed rates and nitrogen fertilizer rates are considered.Grain yield of both varieties was positively correlated with total dry weight of shoot at heading.
Studies on spatial arrangement in sorghum-legume intercropping systems
Authors: Singh S. P. 
Published: March 2009

SUMMARYField experiments on spatial arrangements in intercropping systems were conducted under rainfed conditions in north-western India during 1975 and 1976. In these experiments sorghum yield increased by 21·6, 20·3, 29·2, 36·5 and 14·;2% when grown in association with the legumes greengrarn, blackgram, grain and fodder cow peas and groundnut respectively when compared with sorghum alone. Spatial arrangements had only marginal effect on sorghum yield but the yields of all the intercrops were appreciably affected. Paired rows with two rows of intercrop in 90 cm spacing resulted in maximum yield of all the intercrops. The land equivalent ratio (LER) was also influenced considerably by different intercrops and spatial arrangements. Planting of sorghum in paired rows having two rows of grain cow pea within 90 cm spacing gave maximum LER in both the years; however, net returns were maximum with fodder cow pea in same spatial arrangement.
Animal production from naturalized and sown pastures at three stocking rates under coconuts in the Solomon Islands
Authors: Watson S. E. , Whiteman P. C. 
Published: March 2009

SUMMARYA grazing study, comparing a naturalized and a sown pasture at three stocking rates, was conducted under a uniform stand of 65-year-old coconuts on a fertile soil in the Russell Islands. In a plot trial on this site there was no significant response to application of up to 400 kg N/ha/year over 2 years to Brachiaria decumbens. Average daily transmission of photosynthetically active radiation through the coconut canopy was 60% of full sunlight. The sown pasture consisted initially of para (Brachiaria mutica), signal (B. decumbens) and koronivia (B. humidicola) with the legumes Centrosema pubescens, Pueraria phaseoloides and Stylosanthes guianensis. The main species in the naturalized pasture were Axonopus compressus, Mimosa pudica, C. pubescens and Colopogonium mucunoides. Pastures were set stocked in two replicates over 3 years at 1·5, 2·5 and 3·5 animals/ha. There was no significant difference in live-weight gain between pastures in any year. Live-weight gain per head declined linearly with increasing stocking rate. Highest live-weight gain was 437 kg/ha/year in the 1st year at 3·5 animals/ha. The planted grasses declined from 60% at the start of grazing to 6% 8 months later. A. compressus increased from 2 to 24% over 3 years in the sown pasture, and from 12 to 34% of yield in the natural pasture. M. pudica increased from 27 to 44% in the sown, and remained approximately constant at 37% in the natural pasture. G. pubescens increased at 2·5 animals/ha, but was replaced by P. phaseoloides at 1·5 animals/ha and by A. compressus and M. pudica at 3·5 animals/ha. There were no significant effects of pasture treatments or stocking rate on copra yields. Where there is a cover of naturalized grasses and legumes under coconuts, cultivation and planting of exotic species cannot be recommended. Major improvement will come from thorough weed control and maintaining stocking rates between 1·5 and 2·5 animals/ha.
Prediction of the phosphorus content of herbage consumed by grazing cattle
Authors: Little D. A. , McLean R. W. , Winter W. H. 
Published: March 2009

SUMMARYThe determination of feed phosphorus content using oesophageally fistulated cattle is reported in this paper, from an experiment in which salivary phosphorus was labelled with 32P.An intravenous infusion of Na232PO4 to cattle produced an immediate increase in the specific activity of salivary phosphorus, which then fell rapidly to an essentially linear asymptote by 3 h after the infusion. The phosphorus content of consumed feed was calculated from the degree of reduction in salivary specific activity by the feed phosphorus, expressed as the ratio of the specific activities of bolus and saliva phosphorus.A dose of 100 /μCi 32P allowed the accurate prediction of phosphorus content ranging from 0·07 to 0·25% in various feeds, at intervals from 3 to 24 h after the infusion; the predicted and actual phosphorus concentrations were highly correlated (r = 0·95). Similar observations for feeds ranging from 0·14 to 0·25% phosphorus suggested that accurate prediction was also possible 144 h after infusion. Comparison of estimated feed phosphorus content of grazed material with that measured in hand-plucked herbage indicated that this approach is applicable to grazing studies.
Irrigation and Nitrogen Studies in s. 23 Ryegrass Grown for Seed: 1. Growth, Development, Seed Yield Components and Seed Yield
Authors: Hebblethwaite P. D. 
Published: March 2009

SUMMARYThe effects of irrigation and nitrogen on S. 23 perennial ryegrass grown for seed were investigated in a series of field experiments from 1972 to 1974. Irrigation significantly increased seed yield by 16% in 1972 and 52% in 1974 but had no effect in the wet year of 1973. In 1972 maximum deficit reached 110 mm at the end of July and coincided with anthesis. Consequently the yield response was due to an increase in number of seeds per unit area and no other seed yield component was affected. In 1974 peak deficit also reached about 100 mm but started to build up rapidly very early in the season and had reached 80 mm by the time that the first ears emerged. Consequently the yield response was due to increases in number of fertile tillers, number of seeds per unit area and 1000-seed weight.Irrigation had no significant effect on number of florets or seeds, except in 1974 when percentage of florets which produced seed was increased by 2%.Irrigation had some effect on threshed straw yields, total dry matter, harvest index and total number of tillers but where this occurred the response was much smaller than that of seed yield which indicates that irrigation had greater effects on the reproductive development of the crop than on yield of dry matter and tillering patterns. Increasing the quantity of nitrogen from 0 to 80 kg/ha increased seed yields, all seed yield components except 1000-seed weight, threshed straw yields and total dry matter and number of tillers at most sampling dates. Increasing the quantity of nitrogen from 80 to 160 kg/ha had little further effect on the above components except in 1972 where seed yields were significantly decreased.In 1972 number of florets was increased and percentage of florets which produced seed decreased with increasing quantities of nitrogen.
Evaluation of some sources of fertilizer phosphorus in two cycles of a paddy-wheat cropping sequence
Authors: Hundal H. S. , Deol P. S. , Sekhon G. S. 
Published: March 2009

SUMMARYA field experiment was made on Gurdaspur clay loam to assess the relative efficiency of various sources of fertilizer phosphorus for a paddy-wheat cropping sequence. Urea ammonium phosphate, superphosphate, a nitrophosphate fertilizer containing 30% water-soluble P and fertilizers containing 50 and 70% water-soluble P prepared from the nitrophosphate and superphosphate, dicalcium phosphate and rock phosphate were applied to the paddy crop at the rate of 0, 15, 30, 45 and 60 kg p2O6/ha and to wheat at double these rates.The cumulative yield data for paddy and wheat show a slight reduction in efficiency of phosphatio fertilizers, with the exception of dicalcium phosphate, as their watersoluble content decreased below 70%. In general, the relative efficiency of the less water-soluble sources and of rock phosphate was considerably higher for paddy than for wheat.The results show that the relative efficiency of low water-soluble phosphate fertilizers increased with time. The efficiency of phosphorus fertilizers declined with the rate of their application, more so in the case of higher water-soluble materials.
The growth of hill lambs on herbage diets
Authors: Armstrong Richard H. , Eadie J. 
Published: March 2009

SUMMARYEarly-weaned lambs were penned indoors for 6 weeks and individually fed to appetite on cold-stored ryegrass (Lolium perenne) or indigenousAgrostis-Festucaherbage of differing maturity. In another experiment similar lambs grazed for 12 weeks on swards of perennial ryegrass orAgrostis-Festuca. Live-weight gain (LWG), herbage organic-matter intake (OMI) and digestibility (OMD) were measured. In the indoor experiment ryegrass was 4–6 percentage units higher in OMD than wasAgrostis-Festuca;first harvests were superior to later harvests by the same amount. The intake of ryegrass was 22% greater than that ofAgrostis-Festuca. The correlation between OMI/W'73 and herbage cell-wall constituents was —0·80, and that between OMI/W'3 and OMD was 0·78. OMI/W0·73increased progressively up to about 13 weeks of age.LWG was higher on ryegrass than onAgrostis-Festuca; and LWG on the early harvests of each herbage type exceeded those on the later harvests. LWG was significantly correlated with the intake of digested organic matter (DOMI) (r = 0·85).In the grazing experiment, OMD, OMI and LWG were all lower than in the indoor experiment. LWG on ryegrass was again superior to that onAgrostis-Festuca, and the difference was partly explained by the relationship between DOMI and LWG which had been established indoors.These results suggest that the increase in the growth rates of hill lambs consequent on the improvement of indigenousAgrostis-Festucaswards would be less than that due to the provision of sown pastures of perennial ryegrass.
An inexpensive device for recording seedling emergence force
Authors: Badhoria B. S. , Aggarwal G. C. , Tripathi B. R. 
Published: March 2009

SUMMARYA simple device for recording seedling emergence force was developed. In this device, the relationship between the bending moment and displacement of the free end of a cantilever beam is used to compute seedling emergence force. The growing seedling is forced to push the free end of the beam upwards and the displacement of the free end is recorded with a pointer on smoked paper tightly wrapped on a revolving clock drum.
Regressions, correlations and combining ability of some quantitative characters in peas (Pisum sativumL.)
Authors: Dahiya B. S. , Brar J. S. , Bajaj R. K. 
Published: March 2009

SUMMARYEight cultivars of peas (Pisum sativumL.) were evaluated for six traits in a diallel experiment using regression coefficients, correlations and combining ability estimates. Regression coefficient was high, indicating large additive effects for 100-grain weight. Yield was significantly and positively correlated with plant height, number of pods per plant and 100-grain weight, indicating that selection for either of these would result in higher yield. The best index of yield among the traits studied was number of pods per plant. Significant general combining ability (GCA) variances and specific combining ability (SCA) variances were observed. GCA variances were larger than SCA variances except for yield, suggesting predominance of additive gene effects.
Evaluation of the hydraulic press for measurement of leaf water potentials in cassava
Authors: Palta J. A. 
Published: March 2009

SUMMARYIn the application of the Scholander pressure chamber technique to cassava water relations studies, the leaf water potential measured on central lobules was initially compared with that measured on entire leaves (including petiole). Measurements made using both a Campbell-Brewster hydraulic press and a pressure chamber of the leaf water potential in six different cassava clones were also compared. Although the central lobules showed a greater sensitivity to moisture loss after sampling than entire leaves, their leaf water potential was in close agreement with those measured on the entire leaves (r3 = 0·96). Therefore, for routine and field estimates in cassava, measurements made on the central lobules may be used to avoid the large reduction in total leaf area. The Campbell-Brewster hydraulic press satisfactorily estimated leaf water potential in M.Col. 1684 clone, which had the longest and narrowest lobules, but in other clones the leaf water potential was overestimated at high leaf potential (> -12·5) and underestimated at low water potentials (< -12·5). Over a wide range of leaf water potentials, a poor relationship between leaf water potentials estimated with hydraulic press and with the pressure chamber was observed for cassava because press estimates are influenced by lobule length and lobule width.
Kinetics of Zinc Transformation in Submerged Alkaline Soils in the Rice Growing Tracts of Punjab
Authors: Takkar P. N. , Sidhu B. S. 
Published: March 2009

SUMMARYThe effects of submerging sodic and alkaline soils on the kinetics of Zn2+ transformations were investigated. The soils were treated with 0-640 mg Zn/kg soil as ZnSO4. H2O and kept submerged under water in pots at 30–38 °C. The soil solution was analysed periodically up to 72 days for pH, electrical conductivity and Zn2+ ion. Soil pH decreased with increasing amounts of added Zn and with periods of submergence. The rate of decrease was rapid during the first 21 days of submergence but slow thereafter. Zinc concentration in the soil solution increased with the amounts added and decreased with the period of submergence; this decrease was more in the calcareous sodic soils than in other soils. The values of the expression pZn + 2pOH (Zn. hydroxide potential) showed that in submerged calcareous sodic soils, Zn concentration in the soil solution was regulated both by the Zn (OH)2—Zn2+(aq.) and ZnCO3 — Zn2+(aq.) systems up to 21 days (pZn + 2pOH = 16–17–5), and thereafter predominantly by ZnCO3–Zn2+(aq.) (pZn + 2pOH = 17–6–18–8) as a result of the buffering effect of soil carbonate equilibria. In slightly calcareous sodic and slightly calcareous alkaline soils, the soil solution Zn was controlled transitorily by the system: Zn(0H)2 — Zn2+(aq.) before 2–7 days (pZn + 2pOH = 16–0–17–5), ZnCO3–Zn2+(aq.) from 2–7 to 14–21 days (pZn + 2pOH = 17–5–18–8). Thereafter Zn–soil (unknown solid phases) – Zn=+(aq.) system controlled the Zn solubility (pZn+2pOH = 18–8–20–4).
Field investigations into hypomagnesaemia in dairy cattle, with particular reference to changes in the concentration of blood constituents during the early grazing period
Authors: Bartlett S. , Brown B. B. , Foot A. S. , Head M. J. , Line C. , Rook J. A. F. , Rowland S. J. , Zundel G. 
Published: March 2009

1. In five experiments, groups of milking cows were changed abruptly from winter-stall feeding to graze a number of different swards, and changes in the concentration of blood-serum magnesium and of other blood constituents have been studied.2. Wide variations in the severity of hypomagnesaemia in individual cattle were found in all experimental groups, due possibly to such factors as individual variations in the intake of herbage, the requirement and body reserves of magnesium and the capacity to absorb magnesium from the gut.3. The degree of hypomagnesaemia observed was independent of the level of milk production, but was generally less severe in Friesian than in Shorthorn and Guernsey cattle. The onset of hypomagnesaemia was delayed for a few days in cattle with a high serum-magnesium concentration at the commencement of grazing.4. In two out of three experiments in which the effect of fertilizer treatment was studied, the incidence and severity of hypomagnesaemia was increased by the application to the sward of heavy dressings of nitrogenous fertilizer. In the third experiment, severe hypomagnesaemia occurred on a plot which had received no nitrogen fertilizer, due, it is thought, to a restricted intake of herbage magnesium, since the sward was extremely sparse. The feeding of supplements of flaked maize, crushed barley, crushed dredge corn, molassed sugar-beet pulp or a concentrate mixture balanced for milk production, to grazing cattle did not reduce the incidence of hypomagnesaemia.5. The cutting of grass and feeding it in the stall did not prevent the development of hypomagnesaemia.6. Blood pH and the concentrations of bloodserum calcium, sodium, potassium and blood glucose in cattle were unaffected by a change from winter feed to spring grazing, but a marked change in blood-serum non-protein and urea nitrogen and blood ammonia nitrogen, but not in any other nitrogenous constituents of the serum, was observed. The concentrations of serum non-protein and urea nitrogen and blood ammonia nitrogen were highest in groups of cattle grazing swards which had received a heavy dressing of nitrogen fertilizer and had a high nitrogen content.7. In the two experiments in which the severity of hypomagnesaemia was increased by the application of nitrogenous fertilizer, there was a close group association between high concentrations of blood serum non-protein and urea nitrogen and blood ammonia and low concentrations of blood-serum magnesium. High levels of serum urea and blood ammonia during grazing are thought to reflect a high ammonia production in the gut, which may be responsible for the disturbance in magnesium metabolism which produces hypomagnesaemia.
The ‘tail-end sample’ of stallion semen
Authors: Mann T. , Short R. V. , Walton A. , Archer R. K. , Miller W. C. 
Published: March 2009

1. Measurements of volume, sperm density, ergothioneine, sulphydryl groups and citric acid were made in 100 ‘tail-end samples’ (post-coital penis drips) from thirteen thoroughbred stallions. In addition, a few analyses were made of postcoital vaginal samples.2. The ‘tail-end samples’ were found to differ substantially in their composition from that of the whole ejaculates. They lacked the characteristic gelatinous appearance of normal stallion semen, and had a much lower content of spermatozoa, ergothioneine (sulphydryl groups) and citric acid than an average stallion ejaculate.3. As the variations in volume and composition of the ‘tail-end samples’ collected from different stallions or from the same stallion on different occasions were considerable, it is unlikely that prognostication of fertility could be usefully based on results obtained by analysis of such samples.
Effect of various levels of infestation by the seed weevil (Ceutorhynchus assimilis Payk.) on the seed yield of oil-seed rape (Brassica napus L.)
Authors: Free J. B. , Ferguson A. W. , Winfield Susan 
Published: March 2009

SUMMARYTo determine economic thresholds of pest infestation caged plots of oil-seed rape (Brassica napus L.) were infested with different populations of the seed weevil (Ceutorhynchus assimilis Payk.). Less than one seed weevil per plant resulted in pod infestation levels of seed weevil larvae that by themselves were insufficient to warrant insecticide application, but owing to secondary infestation of pod midge (Dasyneura brassicae Winn.), substantial seed loss occurred. Greater populations of seed weevil adults gave correspondingly larger levels of pod midge and diminishing yields.In commercial crops individual plants were able to compensate, and even to overcompensate for damage resulting from low levels of pest infestation, but increasing levels of infestation resulted in progressively fewer seeds per plant.The implications of the results on pest control and further research are discussed.
Concentrations of potassium in the dry matter and tissue water of field-grown spring barley and their relationships to grain yield
Authors: Leigh R. A. , Johnston A. E. 
Published: March 2009

SUMMARYIn 68 spring barley crops grown in five experiments at Rothamsted and Woburn between 1980 and 1982, and given adequate K fertilizer, there was a positive correlation (r = 0·76; P < 0·001) between maximum % K in dry matter of young plants and the grain yield at final harvest. In all crops changes in % K in dry matter during the growing season were directly related to changes in fresh weight to dry weight ratio (FW: DW) suggesting that differences in % K in dry matter were the result of differences in tissue hydration. Potassium concentrations expressed on the basis of tissue water were not correlated with grain yield. All crops maintained K concentrations in their tissue water of about 200 mmol/kg tissue water, except at the end of the growing season when water loss during ripening caused a steep rise.The correlation between % K in dry matter and yield was the result of differences in FW: DW. Within each experiment there was a good correlation between FW: DW and grain yield, but because the relationship was different for each experiment the overall correlation for all crops was poor. The correlation between FW: DW and grain yield within experiments probably arises because crops with a higher FW: DW will have higher specific leaf areas and hence higher relative growth rates and yields.