bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experiments on the use of anhydrous ammonia for grass
Authors: Gasser J. K. R. , Blakemore Marie , Flint R. C. 
Published: March 2009

SUMMARYA hand injector was used to inject ammonia into soils in pots in which ryegrass was subsequently grown and under grass in the field; the spacing was varied.Injecting ammonia or applying ammonium nitrate at one point or three points in the middle of a clay-loam and a sandy-loam soil in pots did not affect the growth of grass or its uptake of N. Grass with ammonium nitrate grew slightly better than with ammonia on the sandy loam and slightly worse on the clay loam.Best yields of dry matter and most uptake of N were obtained from grass swards having ammonia injected in lines 23 and 30 cm apart and the injection points from onequarter to one-half of the distance between rows. Increasing the distance between lines from 30 to 45 cm diminished total yield and uptake because the strip 15·2 to 22·8 cm from the line of injection grew less than grass nearer to the line of injection.With grass grown in rows 12·1 cm apart, yields were greatest with the lines of injection perpendicular to the rows of grass and least with the ammonia injected along and into the rows. The yield of dry matter of the row with ammonia injected into it was usually less than of the adjacent row and the percentage N in the grass was usually more, so that the weight of N in the grass sometimes increased and sometimes decreased with distance from the line of injection depending on the relative changes in yield of dry matter and of percentage N.
Ovine ill-thrift in Nova Scotia:II. The production of antibiotics by fungi isolated from forest and marshland soil
Authors: Brewer D. , Taylor A. , Hoehn M. M. 
Published: March 2009

SUMMARYThree hundred and seventy-six isolates, or about 9% of the cultures collected in 1967 and 1968 from soil of permanent pasture, that, prior to 1883, supported mixed conifer and deciduous forest, were cultivated in the laboratory. Antibiotic production was detected in 27% of the cultures. Similarly, 329 isolates, or 9% of those collected in the same period from soil of permanent pasture reclaimed from tidal marsh, were grown in the laboratory and antibiotics detected in 30%. The forest soil, because it was already known to have a denser fungal population, thus had a greater antibiotic production potential than the marshland soil. There was a small increase in the number of isolates from the forest soil that produced antibiotics when those obtained in the spring were compared to those collected in the autumn. The opposite relationship was found when the marshland isolates from the two seasons were similarly compared. The results are consistent with the hypothesis that the fungal populations of these soils are a parameter in the aetiology of the ill-thrift that is found in ruminants at Nappan, Nova Scotia.
Culture and fertilization of sheep ovarian oocytes:IV. Observations on sperm penetration in oocytes transferred to the sheep oviduct
Authors: Crosby T. F. , Ryan P. O. M. , Gordon I. 
Published: March 2009

SUMMARYTransfer was made of 2958 sheep ovarian oocytes, cultured in growth medium for 24–30 h, to the oviducts of 142 oestrous sheep; 132 were bred and ten remained unbred. Forty-two per cent of oocytes were recovered, mainly 4–24 h after transfer; tubal flushings were examined for sperm. Evidence of a sperm within the vitellus of follicular oocytes was found in nine recipients, the earliest at 6 h 50 min after transfer. Pronucleate eggs were most frequent 9–14 h after transfer; a limited number of eggs showing normal cleavage wasrecovered.
High-level cereal diets for the growing/finishing pig:V. A comparison of finisher diets containing high levels of maize or barley with wide or narrow calorie/protein/lysine ratios when fed to give two different calorie intakes
Authors: Lawrence T. L. J. 
Published: March 2009

SUMMARYIn an incomplete block 2x2x2 factorial experiment seventy-two Large White type pigs, after having been fed individually and identically up to 120 lb (54·5 kg) live weight, were fed from that weight up to 200 lb (90·9 kg) live weight maize or barley based diets (factor 1), with each diet having either a wide or a narrow calorie/protein/lysine (CPL) ratio (factor 2). The feeding was effected in individual feeders in a Danish type piggery (with six pigs per pen) with all diets offered as wet mashes and according to scales which gave two different calorie intakes (factor 3). There were, therefore, four different diets and eight different feeding treatments.
Selection indices for rabbit improvement
Authors: Khalil M. H. , Owen J. B. , Afifi E. A. 
Published: March 2009

SUMMARYRecords on 884 litters and 3051 bunnies of the Bauscat (B) and Giza White (G) breeds were used to construct different selection indices.A series of selection indices and subindices were constructed for both B and G does. An index or subindex based on litter size at weaning, mean bunny weight at weaning, litter size at birth and litter weight at birth could be practically applied to improve the productivity of B and G does, under local Egytian conditions. Preweaning mortality did not contribute significantly to the different selection indices and subindices. Litter weight at birth made a large contribution to the different indices and subindices constructed. Litter size at weaning contributed little in the subindices to be used to select for mean bunny weight at weaning. Mean bunny weight at weaning made a lower contribution to the subindices to be used to select for litter size at weaning. The expected genetic gain in litter size at weaning was slight in all of the selection indices and subindices constructed because of low heritability values for this trait. Considerable genetic improvement for doe productivity of the G breed might be achieved through selection for mean bunny weight at weaning.Four selection indices and subindices were constructed for B and G rabbits. The index or subindex based on 6-week weight and 8-week weight was the best criterion for selection for the genetic improvement of 6-week weight and 12-week weight. Six- and 8-week weight contributed substantially while 12-week weight contributed little to the value of most of the selection indices and subindices constructed. The highest total genetic gain attributable to 6- and 12-week weight was obtained when the selection indices or subindices including 6-week weight and 8-week weight were used.
The response of grass for silage to sulphur application at 20 sites in Northern Ireland
Authors: Stevens R. J. , Watson Catherine J. 
Published: March 2009

SUMMARYTwenty field site3 were selected for their potential sulphur-deficient status. The effect of sulphur at 10 kg S/ha per cut as gypsum or kieserite on the yield and composition of grass for silage given intensive fertilizer was measured at two or three cuts in 1985. Other incidental sulphur inputs in P and K fertilizers and organic manures were minimized. There were significant increases (P < 0·05) in dry-matter yield at ten harvests on five sites. At seven of the ten harvests gypsum and kieserite were equally effective, but at three harvests only kieserite gave significant yield increases. The drymatter yield increases occurred at all three cuts.Using soil analyses to predict sulphur-deficient sites had limited success. The conclusions from this study were that soils with extractable sulphate values < 10 mg S/l had adequate reserves for three-cut silage while soils with values > 10 mg S/l had a 1 in 3 chance of being sulphur deficient. Using plant analyses to diagnose sulphur-deficient herbage had also limited success. In this study herbage with an N/S ratio > 14 was sulphur deficient while herbage with a ratio > 12 had a 1 in 2 chance of being deficient.The proportion of sulphur responsive sites in this study is an overestimate for Northern Ireland as a whole. Most soils in this country have higher clay and organicmatter contents than the field sites. The application of organic manures in normal agricultural practice is likely to be an important source of sulphur to grass for cutting.
The amylase activity of 14 species of entodiniomorphid protozoa and the distribution of amylase in rumen digesta fractions of sheep containing no protozoa or one of seven different protozoal populations
Authors: Coleman G. S. 
Published: March 2009

The amylolytic activity of the cytoplasmic fraction prepared from 14 single species of rumen ciliate protozoa and two natural mixed populations has been determined using five different assays. All the protozoa contained an a-amylase and the major product of amylose digestion was maltose. The highest activities were found inEremoplastron bovis, Diploplastron affine, Ophryoscolex caudatus and Polyplastron multivesiculatumgrown in vitro on grass and wholemeal flour and the lowest inOstracodinium obtusum bilobumandDiplodinium pentacanthumunder all growth conditions and in culturedEntodinium bursaandE. caudatum. The maximum activities depended on the substrate and withEremoplastronbovis varied from 2·3 (with starch grains) to 48·8 (with amylose) μtmol maltose produced/mg protein per h.The distribution of amylase between various rumen fractions has been determined at three times after feeding in sheep containing no ciliate protozoa or seven different protozoal populations. A method to give maximal release of the enzyme from mixed rumen bacteria was devised and three different assay methods were compared. The total rumen amylase varied by up to 2·6 times and was highest in animals that contained onlyEntodinium caudatumor natural A- or B-type populations. The distribution of amylase activity between rumen fractions varied considerably with the various protozoal populations, that in the protozoal cytoplasm being highest in animals containingEpidinium ecaudatum caudatum(46–53%) and the natural A- and B-type populations (35–57 %) and lowest in the animals containing no protozoa (3–11 %) or onlyOstra-codinium obtusum bilobum(6–21%). The reverse was true for the activity in the bacterial fraction which contained little activity in animals with natural A- and B-type populations and over 58% of the total activity in an animal containing onlyEntodinium caudatum. The lowest activities in all fractions were obtained 1·5 h after feeding. Comparatively little activity was found in the plant debris or clarified rumen fluid fractions from any animal. Using results obtained previously the ratios of carboxymethylcellulase to amylase activities have been calculated and shown to be highest in the protozoal cyto-plasmic fraction ofDiplodinium pentacanthumandOstracodinium obtusum bilobumandlowest in Entodiniumspp.,Diploplastron affineandEremoplastron bovis.
Effects on egg production and quality of supplementing the diet of hens laying brown eggs with blood meal and magnesium chloride
Authors: Karunajeewa H. , Abu-Serewa S. , Tham S. H. , Harris P. A. 
Published: March 2009

SUMMARYIn a 2 × 4 factorial experiment, the laying performance of hens given diets with or without blood meal and four concentrations (0, 5·71, 11·43 and 17·14 g/kg) of added magnesium chloride was measured for 280 days. The inclusion of 50 g/kg blood meal in the laying diet reduced the rate of laying (P < 0·05), egg weight (P < 0·01), egg output (P < 0·01), food intake (P < 0·01), body weight gain (P < 0·01) and body weight at 457 days (P < 0·05). It increased the height of albumen (P < 0·05), Haugh unit score (P < 0·01) and shell colour intensity (P < 0·05) of fresh eggs. The inclusion of increasing dietary concentrations of magnesium chloride reduced (P < 0·01) the specific gravity of eggs but had no significant effect on any of the other egg quality or production characteristics. The dietary treatments had no significant effect on Haugh units of stored eggs.
Effects of nitrogen application on growth characteristics of signal grass (Brachiaria decumbens)
Authors: Okeagu M. U. , Asiribo O. E. , Akinola J. O. 
Published: March 2009

SUMMARYSignal grass (Brachiaria decumbens Stapf.) given 100, 200, 300 and 400 kg N/ha and protected from defoliation by growing in cages was evaluated for tiller height, tiller density and dry matter (DM) yield in 1979 and 1980.Nitrogen rate had highly significant linear effects on tiller height and density and DM yield of the grass at each age of pasture regrowth and at all the ages of pasture regrowth combined in 1979 and 1980. The quadratic effect of N rate was not significant in either year.The positive linear responses shown by the growth of tillers and the overall yield of the grass at N rates up to 400 kg/ha suggest that further work, using N rates above 400 kg/ha, is needed to ascertain the optimum N requirement of this grass.
Effects of bracken litter and frond canopy on emergence and survival of ryegrass and white clover seedlings
Authors: Lee H. C. , Cooke J. A. 
Published: March 2009

SUMMARYTwo field experiments, at Woolly Hills Farm, County Durham, UK, and a glasshouse experiment were carried out in 1977. Early in the growing season (May-July), a covering of bracken litter increased the number of ryegrass and clover seedlings which became established both in an area where bracken had been removed and where there were developing fronds. In a second experiment (August-October), bracken litter had no effect on seedling establishment in the open. Under the frond canopy, the absence of litter was beneficial to clover establishment. The frond canopy reduced the number of ryegrass seedlings by half compared with the numbers in the open. In the glasshouse, litter caused a small reduction in the numbers of ryegrass and clover seedlings becoming established.The results suggest that litter may be either beneficial because of the prevention of desiccation in dry periods or detrimental, perhaps through allelopathic effects or shading. In terms of the successful establishment of a sown grass and clover sward, it would seem that litter removal by incorporation or burning is more justified in upland hill pastures because of the need to improve soil fertility than because of adverse effects of the litter itself.
A field study of the number of main shoot leaves in wheat in relation to vernalization and photoperiod
Authors: Kirby E. J. M. 
Published: March 2009

SUMMARYThe number of leaves formed on the main shoot of a wheat plant is an important developmental feature, and a method of predicting this is essential for computer simulation of development.A model function was used to estimate vernalization from simulated sowing dates throughout a season. When expressed in terms of thermal time, it was estimated that a plant might be fully vernalized soon after seedling emergence or take up to about 1000 °Cd, depending on sowing date. When the simulated progress of vernalization was related to main shoot development (primordium initiation and leaf emergence) it was found that there were substantial differences between sowings in the rate of vernalization at comparable stages of apex development.A number of field experiments done in Britain from 1980 to 1984 with prominent commercial varieties, sown at various times from September to March, were analysed in terms of the thermal time to full vernalization and the photoperiod at the time of full vernalization, with vernalization simulated by the model function. In both winter and spring varieties, both of these variables significantly affected the number of main shoot leaves. Multiple linear regression using these two variables accounted for between 70 and 90% of the variance in leaf number, depending on variety.
Analysis of post-flowering compensatory growth in winter oilseed rape (Brassica napus)
Authors: Tommey A. M. , Evans E. J. 
Published: March 2009

SUMMARYPatterns of assimilate distribution in single plants of winter oilseed rape (Brassica napus L.) cv. Mikado, following a reduction in sink capacity at flowering were investigated in two field experiments during the 1985/86 and 1986/87 growing seasons at Cockle Park Experimental Station, Northumberland. Plants demonstrated considerable compensatory growth following the removal of flowers from the terminal raceme and primary branches.Flower removal from lower branches did not significantly reduce total seed weight. Plants with a pod-bearing terminal raceme and one, two or three productive higher-order branches yielded a similar amount of seed. When seed production was confined to the terminal raceme and first four primary branches, seed yield per plant was greatly increased. Removal of flowers from the terminal raceme and uppermost branches of plants increased the number and productivity of lower-order branches but not enough to offset the overall loss in seed yield potential per plant. Indeed, when flowers were removed from higher-order racemes, the reduction in total seed weight per plant, was directly related to the degree of flower removal. The additional seed yield obtained from individual branches of modified plants in both experiments arose largely through an increase in fertile pod number and seed number per pod. Flower removal treatments did not greatly influence mean seed weight.The results clearly demonstrated that the loss of flowers from lower-order branches could be tolerated and may even be beneficial. Conversely, the removal of flowers from higher-order branches resulted in significant yield reductions. The production of lower branches should be restricted, therefore, in order to increase the superiority of the terminal raceme and uppermost branches and to increase the overall production efficiency of the crop canopy.
Effects of plant population density on spring-sown field beans (Vicia faba) with different growth habits
Authors: Pilbeam C. J. , Duc G. , Hebblethwaite P. D. 
Published: March 2009

SUMMARYDeterminate varieties of Vicia faba are smaller and may require higher plant population densities than their conventional indeterminate counterparts to attain high yields. This hypothesis was examined at the University of Nottingham farm at Sutton Bonington, UK, and at INRA, Dijon, France in 1986 and 1987. The determinate varieties Ticol and TP667 and indeterminate M5.1 and Maris Bead were sown in the spring to give a range of densities of 10–100 plants/m2.Yields generally increased as population density increased. The optimum density for determinate varieties was higher than for indeterminate varieties. Indeterminate varieties yielded more than determinate varieties at all plant densities, perhaps because of their larger canopy. Seed yields were affected by year and location. Greater yields were associated with heavier seeds and more seeds per pod.Although several yield components, when expressed per unit area, were significantly correlated with seed yield, their coefficients of determination were never very large. This confirmed the plasticity of yield in field beans.
Carbohydrate digestibility and nitrogen metabolism in sheep fed untreated or sulphur dioxide-treated wheat straw and poultry litter
Authors: Miron J. , Solomon R. , Yosef E. , Ben-Ghedalia D. 
Published: March 2009

SUMMARYDigestibility of neutral detergent fibre (NDF) and monosaccharide components of diets containing 60% untreated straw (UTS) or straw treated with sulphur dioxide (TS) and poultrylitter (1:1) plus 40% concentrate at 700 g/day intake was examined in sheep equipped with rumen and duodenal cannulas. An all-concentrate diet (CD) served as a reference ration. The SO2 treatment of straw increased the apparent digestibility of the NDF, glucose, xylose, arabinose and galactose components of the diet from 58·9, 86·7, 55·7, 82·5 and 91·8%, respectively, in the UTS diet to 73·8, 92·6, 77·8, 88·9 and 94·6%, respectively, in the TS diet. Whereas digestion of NDF and glucose in sheep on the TS diet was slightly lower than in those on the CD diet, digestion of xylose, arabinose and galactose was higher. Thus, the digestibility of total monosaccharides in th TS diet was 90·2 % and that of the CD diet only 61% units higher. The SO2 treatment also increased the total rumen volatile fatty acid (VFA) concentration and the proportion of butyric acid in the total VFA compared with the UTS diet.Rumen ammonia concentration was 7 mg/100 ml lower and nonammonia nitrogen (NAN) flowto the duodenum was 1·3 g/day higher in sheep fed the TS diet compared with the CD diet. The quantity of duodenal N absorbed in the intestine was 10·7 g/day in the TS diet, close to the value of 11·6 g/day found with the CD diet.The similarity between the TS and CD diets in total monosaccharides digestion and duodenal Nabsorption, confirms the findings of earlier studies that a TS diet is a highly productive ration.Complementary interaction between the SO2-treated straw and poultry litter components of the TS diet is discussed.
Mathematical modelling of ammonia volatilization from slurry stores and its effect onCryptosporidiumoocyst viability
Authors: Ruxton G. D. 
Published: March 2009

SUMMARYA simple mathematical model is shown to provide reasonably good predictions of time series data on ammonia loss from three experiments on slurry stores. The model produces predictions of changes in the distribution of ammonia with depth. Experimental evidence suggests that ammonia concentrations above a critical value appear to destroy the viability ofCryptosporidiumoocysts. Using this criterion, the model predicts that, even under the most favourable circumstances, oocysts are unlikely to remain viable in slurry stores except in the top few centimetres. The effect of stirring the slurry is considered.
Protein metabolism in lambs from lines divergently selected for weaning weight
Authors: Oddy V. H. , Speck P. A. , Warren H. M. , Wynn P. C. 
Published: March 2009

SUMMARYThe physiological consequences of selection for weaning weight were investigated using 14-month-old castrated male Merino lambs from lines selected for (W +) and against (W – ) weight at weaning for over 10 generations. The selection experiment commenced in 1953 and was conducted at Trangie, NSW, Australia. Lambs from these lines now differ by 42% in weight at weaning and maturity, and have a proportionately similar composition of protein, fat and ash in their bodies at similar stages of maturity. In the whole body, there were no apparent between-strain differences in protein synthesis, but W + lambs had lower (P < 0·05) rates of phenylalanine oxidation than W – lambs. In hind limb muscle, protein metabolism of W + lambs was more responsive to food intake than in W – lambs. In particular, the rate of change of protein degradation differed (P < 0·05) between the lines in response to food intake per unit liveweight with protein degradation decreasing with increased feed intake in W + lambs. W + lambs had lower (P < 0·05) rates of blood flow to, and used less (P < 0·05) oxygen per kg hind limb muscle than W— lambs. Endocrine differences between the lines included increased (P < 0·05) plasma insulin-like growth factor-I (IGF-1) concentration in W + compared to W— lambs and, from regression analysis, an indication that there was a higher (P < 0·01) response in hind limb protein gain to insulin in the W + lambs.These results suggest that selection for weaning weight has altered the dynamics of protein metabolism in lambs, principally through alterations in protein breakdown in muscle. Moreover, they suggest that there are associated genetic differences in endocrine control of protein metabolism which involve insulin and possibly IGF-I.