bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of markers to measure digesta flow from the stomach of sheep fed once daily
Authors: Faichney G. J. 
Published: March 2009

SummaryTwo methods for calculating the flow of digesta and its constituents from the concentrations of two markers, 51Cr-labelled chromium EDTA (51Cr-EDTA) and 103Ru-labelled ruthenium phenanthroline (103Ru-P), and digesta composition were compared in fistulated sheep fed once daily and in other fistulated sheep fed continuously. One method uses the marker concentrations to calculate the flow of whole digesta directly (double-marker) whereas the other uses the markers to calculate separately the flow of fluid and non-filtrable particles, the sum of which is digesta flow (two-marker).When feed was given continuously, flow values calculated using the double-marker method and the two-marker method, which requires a correction to be made for nonideal behaviour of 51Cr-EDTA, did not differ. When feed was given once daily, the double-marker method consistently overestimated flow relative to the corrected twomarker method but the differences were extremely small (less than 0-8% for digesta flow and 0-5% for nitrogen flow). 51Cr-EDTA as a single marker slightly overestimated digesta flow (up to 2·3%) but grossly overestimated nitrogen flow (up to 22·5%); 103Ru-P as a single marker grossly underestimated both digesta flow (up to 30·5 %) and nitrogen flow (up to 23·1%).It was concluded that the double-marker method is to be preferred when the diet is given continuously or frequently at fixed intervals. When the diet is given once daily, the two- and double-marker methods can be expected to give similar values. Single markers should not be used for estimating the flow of digesta and its constituents when samples are taken from a simple cannula.
Live-weight, total body-water and maternal body-solid changes in pregnant and lactating beef cows
Authors: Degen A. A. , Young B. A. 
Published: March 2009

SummaryLive weight and total body water (TBW; measured as tritiated water space) were measured in eight pregnant cross-bred beef cows from the 6th month of gestation to approximately 1 month after calving. Using the values from these measurements and by estimating foetal, foetal fluid and foetal membrane weights from previously established prediction equations, the maternal live weight, maternal body water and maternal body solids were calculated.Live weight, TBW, maternal body water and maternal live weight increased during gestation, whereas maternal body solids decreased. The TBW percentage of live weight increased from 74·8 to 79·6% during gestation and remained at about 79·5% during the first month of lactation.It was concluded that live-weight changes alone could be misleading in assessing the energy balance of pregnant ruminants not only because of development of the foetus and associated structures but also because of maternal hydration.
Sorghum-pigeonpea intercropping and the effects of plant population density
Authors: Natarajan M. , Willey R. W. 
Published: March 2009

SummaryAn intercropping experiment is described in which three plant population densities of an early sorghum (82 days) were factorially combined with three plant population densities of a later-maturing pigeonpea (173 days) in a standard 2 sorghum:1 pigeonpea row arrangement. Sorghum growth was not affected by the presence of pigeonpea, and the farmers' primary objective of maintaining a ‘full’ sorghum yield was achieved if the density of the intercropped sorghum was equivalent to the sole crop optimum.The spatial distribution of roots after 30 and 60 days of growth did not appear to be altered by intercropping, and roots of the two crops were found to intermingle freely.
Sweating response in cattle and its relation to rectal temperature, tolerance of sun and metabolic rate
Authors: Finch Virginia A. , Bennett I. L. , Holmes C. R. 
Published: March 2009

SUMMARYSweating rates were analysed in relation to rectal temperatures of cattle to yield a measure of sweating response within and between animals. The measurements, performed over 36 days, were done in a natural radiant environment on six steers in each of three breeds, Brahman (B), Brahman × Hereford–Shorthorn cross-breds (BX), and Shorthorn (S). Each steer was recorded for 30 min on six occasions randomly distributed among 6 h between 08.00 and 13.00 h, and on six occasions between 11.00 and 16.00 h, all on different days. Sweating response, e.g. the linear slope of the relationship between sweat rate and rectal temperature, was greater for B (294 g/m2. h/°C) than for BX (146 g/m2.h/°C) or S (194 g/m2.h/°C) which did not differ; this helped to explain why the range and mean rectal temperature in B were lower and little affected by environmental heat. Curvilinear models of the sweating response indicated that in the environmental conditions of this study, the limit of sweating for B and BX was not reached, while for S, the sweating response approached a plateau. Between animals, the relationship of sweating response to mean rectal temperature was negative (P < 0·01) and its relationship to the time spent in the sun at pasture positive (P < 0·025). Thus this measure of sweating response was a good indicator of thermoregulatory ability of the cattle. However, the sweating response of the steers did not relate to their grazing time or growth. The reasons for this are discussed. Finally, the sweating response was found to be negatively correlated with metabolic rate between animals within breeds (P < 0·01) and this suggested that it may be difficult to combine the desirable traits of good heat adaptation and high metabolic potential in cattle.
Growth of spring barley under drought: crop development, photosynthesis, dry-matter accumulation and nutrient content
Authors: Lawlor D. W. , Day W. , Johnston A. E. , Legg B. J. , Parkinson K. J. 
Published: March 2009

SUMMARYThe effects of water deficit on growth of spring barley were analysed under five irrigation treatments. One crop was irrigated at weekly intervals from emergence throughout the growing season, and one was not irrigated at all after emergence. Soil water deficits in the other treatments were allowed to develop early, intermediate or late in the crop's development.Weekly irrigation produced a crop with a large leaf area index (maximum value 4) and maintained green leaf and awns throughout the grain-filling period. Early drought decreased leaf area index (maximum value 2) by slowing expansion of main-stem leaves and decreasing the number and growth of tiller leaves. Leaf senescence was also increased with drought. Drought late in the development of ears and leaves and during the grain-filling period caused leaves and awns to senesce so that the total photosynthetic areas decreased faster than with irrigation. Photosynthetic rate per unit leaf area was little affected by drought so total dry-matter production was most affected by differences in leaf area.Early drought gave fewer tillers (550/m2) and fewer grains per ear (18) than did irrigation (760 tillers/m2 and 21 grains per ear). Late irrigation after drought increased the number of grains per ear slightly but not the number of ears/m2. Thus at the start of the grain-filling period crops which had suffered drought early had fewer grains than irrigated (9·5 and 18·8 × 103/m2 respectively) or crops which suffered drought later in development (14 × 103/m2).During the first 2 weeks of filling, grains grew at almost the same rate in all treatments. Current assimilate supply was probably insufficient to provide this growth in crops which had suffered drought, and stem reserves were mobilized, as shown by the decrease in stem mass during the period. Grains filled for 8 days longer with irrigation and were heavier (36–38 mg) than without irrigation (29–30 mg). Drought throughout the grainfilling period after irrigation earlier in the season resulted in the smallest grains (29 mg).Grain yield depended on the number of ears, the number of grains per ear and mass per grain. Early drought decreased tillering and tiller ear production and the number of grains that filled in each ear. Late drought affected grain size via the effects on photosynthetic surface area.Drought decreased the concentrations of phosphorus, potassium and magnesium in the dry matter of crops, and irrigation after drought increased them. Concentration of nitrogen was little affected by treatment. Possible mechanisms by which water deficits and nutrient supply affect crop growth and yield are discussed.
Changes in magnesium and calcium in soils of the Broadbalk wheat experiment at Rothamsted from 1865 to 1966
Authors: Bolton J. 
Published: March 2009

SUMMARYChalk in the 0–9 in topsoil of Broadbalk has declined from nearly 5% in 1865 to less than 1 % in some plots in 1966, and fastest in plots given ammonium sulphate. Losses were equivalent to 5–8 cwt limestone/acre annually. The paper relates these rates to estimated anion losses, especially bicarbonate, from the plots. Af-ammonium acetate dissolved Ca and Mg from chalk particles in the soils. After correcting for this, exchangeable magnesium had increased during the first 50 years but decreased since 1914 in the F.Y.M. plot. In plots given none or 10 lb/acre of magnesium in fertilizer annually, exchangeable magnesium had changed little since 1865. Thissuggests that equilibrium was soon established between additions and losses of Mg in all except the F.Y.M. plots. Estimates of annual additions and losses of Mg from each plot show that an equilibrium is feasible without large gains from non-exchangeable soil resources. A method of calculating losses of Mg in the drainage using activity ratios and annual calcium losses was developed.
The accuracy of a range of capacitance probe methods for estimating pasture yields
Authors: Johns G. G. 
Published: March 2009

SUMMARYNine different capacitance probe methods were used to estimate the herbage yields of 32 small pasture plots; ten meter readings were used in conjunction with the yield data from a variable number (n) of quadrats in each plot. Expected yields were determined by cutting ten quadrats per plot. Estimated yields were compared with expected yields for both the differing methods and the differing values of n. At each level of n the yield estimates from the different probe methods were compared with those obtained simply by cutting n quadrats.Using calibration data from only one quadrat per plot (n = 1), all probe methods except one gave greater accuracy than that obtained from the single quadrat yields only. For n = 2, the advantage of the probe methods was less pronounced and where n = 3 only one probe method (one which involved no regression computations) gave superior accuracy to that obtained merely by using the yield data from the three cut quadrats. At n > 3, only the one probe method gave increased precision; all other probe methods were markedly less accurate than the equivalent raw quadrat results.Only one probe technique (which combined data from markedly dissimilar swards) gave yield estimates which were noticeably biased.Results from an earlier study are presented to demonstrate the influence of season, species and irrigation on probe calibration.Recommendations are made on the various probe methods which may prove effective in some experimental situations.
An analysis of the relationship between potential evaporation and dry-matter accumulation for winter wheat
Authors: Green C. F. , Vaidyanathan L. V. , Hough M. N. 
Published: March 2009

SUMMARYSequential dry-matter measurements for winter wheat crops grown at different sites during different seasons were plotted against accumulated potential evaporation. A relation consisting of two intersecting straight lines represented the observations. Early crop growth had a gentle slope due to an incomplete leaf canopy. Later growth occurred at a rate which depended upon the amount of applied nitrogen, the amount of radiation and the availability of water. The intersection occurred consistently at a leaf area index of 1·25.
Carcass characteristics of indigenous breeds of cattle in Nigeria
Authors: Buvanendran V. , Ikhatua U. J. , Abubakar B. Y. , Olayiwole M. B. 
Published: March 2009

SUMMARYBunaji and Sokoto Gudali breeds of cattle were fattened and slaughtered at live weights of 250, 300 or 350 kg. After the carcasses were jointed into commercial cuts, the joints of the left side were dissected into lean, bone and fat. Dressing percentage was significantly higher in Bunaji carcasses (52·5%) than in Sokoto Gudali carcasses (50·3%). The lean percentage was nearly constant at 68·69% at all slaughter weights whereas fat percentage increased from 10·3 at 250 kg to 14·5 at 350 kg. Bone percentage was inversely related to fat percentage. The relative growth coefficients of muscle and fat were 1·28 and 1·80, whereas that of bone was 0·59. Significant changes in proportion of carcass parts and tissues were observed with increased slaughter weight. The proportion of hind decreased and that of back and belly increased, while chuck and shank remained relatively unchanged. Lean percentage was relatively unchanged by slaughter weight in all carcass parts except the chuck where it increased. The greatest increase in fat percentage was in the belly (7·6%) followed in decreasing order by the back (5·4%), shank (4·9%), hind (3·0%) and chuck (1·8%). The breeds did not differ in any of the traits except dressing percentage.
The effect of different degrees of food restriction in late pregnancy on nitrogen metabolism in ewes
Authors: Espinosa R. Valdez , Robinson J. J. , Scott D. 
Published: March 2009

SUMMARYNine individually penned Finnish Landrace x Dorset Horn ewes with a mean litter size of 2·33 were offered a diet containing 63% digestible organic matter (DOM) and 13% crude protein in the dry matter at a daily intake of 0·82 kg DOM (1·3 x maternal maintenance) from 95 to 110 days of gestation. On day 111 DOMI was abruptly reduced to either 0·67 kg (T1, 0·54 kg (T2) or 0·36 kg (T3)/day and kept at these levels until a few days pre-partum.Daily N balance before food restriction was 4·9 ± 0·51 g/day. During the periods 3·9 (S1), 11·17 (S2) and 19·25 (S3) days after food restriction daily N balance was 2·8, 2·8 and 3·6 g for θwes on T1, 1·0,1·0 and 0·8 g for those on T2 and –4·1, -4·0and -4·0 g for those on T3. Total lamb birth weight was 8·0, 7·2 and 6·5 kg for treatments T1, T2 and T3 respectively. Using regression analysis it was calculated that plasma glucose concentration in late pregnancy for ewes with a total lamb birth weight of 8 kg fell below the pre-restriction value of 52 mg/100 ml when daily DOMI was reduced to 747 g. At this intake the plasma FFA concentration was 585/i-equiv./I compared with 288 before food restriction. Corresponding values for daily N balance were 5·1 and 4·9 g. A reduction in daily energy intake below 0·75 kg DOM resulted in a rapid decrease in plasma glucose and N balance, the latter being proportional to the increase in the concentration of plasma FFA. The mean daily loss of N from the maternal body was estimated to be 0·4, 1·6 and 6·1 g for treatments T1 to T3 respectively during the period of food restriction.
Competition studies in diploid and tetraploid varieties of Lolium perenne: 2. The inhibition of germination
Authors: Harries J. H. , Norrington-Davies J. 
Published: March 2009

SUMMARYSeed extracts prepared by soaking ryegrass seed in water were tested for their ability to suppress germination. The tests were carried out by sowing seed on to sand-filled basins moistened with seed extract.Extracts prepared from the two diploid varieties, S. 24 and Hora and the tetraploid variety Terhoy were able to reduce both the rate of germination and the final percentage germination when applied to the sown seed. The details were as follows, (i) When S. 24 perennial ryegrass seed was used to obtain the extract inhibition was found to be related to the concentration of the extract, (ii) The final germination of diploid seed was reduced by 16% in the presence of its own seed extract and by 27% when tetraploid seed extract was applied, (iii) The final germination percentage of the tetraploid seed was reduced by 14% in the presence of either its own extract or that prepared from the diploid seed, (iv) Simple chemical tests carried out on the seed extract, although not conclusive, gave some indication that the inhibitory substance may have been a member of the alkaloid group.
The effect of soil type and related factors on sugar beet yield
Authors: Webster R. , Hodge C. A. H. , Draycott A. P. , Durrant M. J. 
Published: March 2009

SUMMARYYields of sugar and responses to fertilizers were determined in about 400 fertilizer experiments on farms throughout the sugar-beet growing areas of Britain during 14 years from 1957 to 1970. The soil at each experimental site was described and classified and the records of the experiments have been examined to determine which properties of the soil influence sugar yield. The effect of year, rainfall, elevation, region and other factors such as sowing and harvesting date were also investigated.Year-to-year variation accounted for 20 % of all variation in yield; increasing amounts of rainfall during the growing season appeared to decrease yield. There was a significant long-term trend of increasing sugar yield from the experiments of 0·042 t/ha/year. The experimental yields closely followed national yields each year but were always greater. Delay in sowing and early harvesting depressed yield by 0–02 and 0·01 t sugar/ ha/day respectively. Yields in Scotland (average 5·23 t/ha) were approximately 1·4 t/ha less than in England and Wales, but there were no evident regional differences within England and Wales.Soil regarded as moderately drained yielded better than either well-drained or imperfectly drained soil, which in turn yielded better than droughty and poorly drained soil. The difference in the adjusted yield between drainage classes was 1·0 t/ha. Surprisingly, topsoil texture had no consistent effect on mean yield (as distinct from response to fertilizer). Subsoil texture, however, had an appreciable effect, the crop on sandy subsoil and chalk or limestone yielding poorly whilst that on silt or peat yielded best. The range of differences in sugar yield due to subsoil texture was almost 2 t/ha.Yields were also examined in relation to soil profile type. Broad division into major soil groups gave meaningful differences but fine division by soil series was only useful for the 11 series on which at least ten experiments had been made. The crop yielded most sugar on gleyed calcareous soils, peats and humic gleys, and least on rendzinas and brown calcareous soils. Responses to nitrogen and potassium but not to phosphorus were affected by both topsoil and subsoil texture. Nitrogen and potassium both increased yield most on sandy soils and least on fine silts and peats.The morphology, chemical and physical condition of soil clearly affect sugar yield greatly and further research is needed in experiments planned specifically to measure their influence and provide more precise guidance for selecting the best land for the crop.
The Effect Of Grazing Compared With Cutting, at Different Frequencies, On a Lucerne-Cocksfoot Ley
Authors: Wilman D. 
Published: March 2009

SUMMARYGrazing with sheep was compared with cutting, in each case at three frequencies, four, five and six defoliations per year, on a lucerne—cocksfoot ley. The treatments were applied in one year and their effects measured during that year and at cuts in June and August of the following year. One experiment began in 1963 in the second harvest year of a ley and a second began in 1964, on an adjacent site, in the third harvest year of the ley. Cutting four times in the year allowed lucerne to persist satisfactorily in both experiments. In the 1964 experiment cutting five or six times and grazing rather than cutting had no apparent, serious, adverse effect on the lucerne compared with cutting four times. In the 1963 experiment, however, increasing the number of cuts and grazing rather than cutting had a large adverse effect on the lucerne, and in the most extreme treatment, grazing six times, the proportion of lucerne was reduced to 2 % of total herbage yield the following June compared with 66% on the four-cut treatment. The contrasting results in the two experiments seem associated with weather differences, 1964 being a much drier, more sunny growing season than 1963, and perhaps with the differences in age of sward, individual lucerne plants perhaps having bigger roots with more reserves in 1964 than in 1963. During the treatment year increasing frequency of defoliation tended to increase the N content of both species and grazing compared with cutting generally increased the N content of cocksfoot. During the year following the treatment year the N content of the two species was little affected by the experimental treatments. The implications for farm practice are considered.
Soil characteristics and nutrient indexing of vineyards in Punjab, India
Authors: Arora C. L. , Hundal H. S. , Takkar P. N. 
Published: March 2009

SUMMARYA survey of 46 vineyards was conducted to determine whether some nutritional disorder was the cause of declining yields. The surface soils, in general, are alkaline, calcareous, medium to high in organic matter, light in texture and sufficient in available micronutrients except B. Petiole analysis indicated a deficiency of Zn, Fe, Mn, B and Cu in 70, 52, 37, 20 and 13% as well as an excess of P and K in 35 and 93% of the vineyards respectively.Significant negative correlations of P with Fe and Mn and that of K with Zn showed that the lack of Fe, Mn and Zn might have been induced by excessive application of P and K fertilizers. Poor correlations between the DTPA-soluble concentrations of Cu, Fe, Mn and B in the soils and those in the petioles suggested the nutrient status of surface soils to be of little value in the nutrition of grape vines or that the petiole may not be the best tissue for this purpose.
Effect of sowing date and soil type on plant survival and grain yield of chick peas (Cicer arietinum L.)
Authors: Ageeb O. A. A. , Ayoub A. T. 
Published: March 2009

SUMMARYSowing date directly affected the grain yield of chick peas. Optimum sowing date was found to be between the end of October and the end of November, but different soil types showed some differences within this optimum.Grain yield was highly correlated with number of pods per plant and number of plants at harvest.Plant loss at the seedling stage was highly correlated with daily mean maximum air temperature, and was also significantly associated with sodium accumulation in shoots.