bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive significance of red cell potassium types in buffaloes
Authors: Sengupta B. P. 
Published: March 2009

SUMMARYThe possible adaptive significance of the occurrence of HK and LK red-cell types in Murrah buffaloes was investigated. Judged by haematological indices and thermorespiratory responses under conditions of moderate thermal stress, LK animals appeared to have a greater adaptive potential than HK animals in a hot arid environment. Dry matter percentage, packed cell volume (pcv), haemoglobin concentration (Hb), red blood corpuscles (RBC) and plasma protein values were significantly higher in LK-type animals. In addition, under identical conditions of thermal stress the LK animals exhibited significantly less rise in rectal temperature and respiratory rate than the HK animals.
Interactions between genotype and density on the yield components of Zea mays: I. Production of dry matter by the shoot
Authors: Voldeng H. D. , Blackman G. E. 
Published: March 2009

SUMMARYThe interacting effects of genotype and density on the yield of dry matter by mature shoots were examined at Oxford, England. There were six hybrids, either pure dent or flint × dent crosses, together with two open-pollinated flint varieties of very early maturity. Over a range of 15 densities (5·0–30·8 plants/m2) for all the genotypes the relationship between the yield of the shoot and density can be adequately described by the reciprocal equation 1/w = A + Bp, where w = weight per plant, p = number of plants per unit area and A and B are constants for any particular set of conditions. Values of both 1/B (asymptotic yields) and 1/A (weight per plant at very low densities) were dependent upon the genotype. In a regression analysis between 1/w and p, the variance of 1/w was over 40 times as great at high as at low densities and a weighted analysis was necessary. Some hybrids approached maximal yields at 5 plants/m2, whereas others required a density of 10–15 plants/m2. The possible reasons for these interactions are discussed and improvements in experimental design suggested.
Composition of beef carcasses: III. The reliability and use of visual assessment
Authors: Harries J. M. , Pomeroy R. W. , Williams D. R. 
Published: March 2009

SUMMARYThe technique of visual appraisal of intact sides of beef was used on most of the carcasses previously described in Parts I and II of this series. Tests of discrimination and consistency were carried out for each of the judges taking part, and their assessments were compared with the results of subsequent dissection of the carcasses.It was found that visual appraisal of the subcutaneous fat content of a carcass was very good, especially with the aid of photographic standards, though a curious tendency to match the standards consistently to carcasses of a higher proportion of fat than those used for the photographs themselves was apparent. This did not materially affect the use that can be made of visual judgements in predicting fat content and it was found that expert judgement alone is capable of predictive accuracy roughly equal to that obtained from simple measurements, though not as good as that obtained by partial dissection, as described in Part II. Equations are given for the prediction of carcass composition, using visual appraisal in combination with other variables.The appraisal of conformation was not so successful; reasons for this are advanced, and suggestions made for future improvement.
Utilization of berseem hay by ruminants
Authors: Sharma V. V. , Murdia P. C. 
Published: March 2009

SUMMARYFour young females of four ruminant species, namely cow, buffalo, sheep and goat were used to study the utilization of sun-cured berseem hay (20·6% CP) fed in long form during a 28-day experimental period. Voluntary intake of hay was estimated during the last 10 days and digestibility of feed nutrients and nitrogen balance during the last 6 days.The digestibility coefficients of dry matter (D.M.), organic matter (OM), crude protein (CP), crude fibre (CF), ether extract (EE) and nitrogen-free extract were higher for sheep and goat than for cow and buffalo but such differences were significant for D.M., OM and CP only. The daily D.M. intake was 3·56, 3·17, 0·92 and 0·63 kg/animal and 82·5, 81·2, 70·4 and 65·1 g/kg W0.75 in buffalo, cow, sheep and goat, respectively, but intake of total digestible nutrients (TDN) relative to metabolic body size was similar for all species.Buffalo was superior to the other three species and cow to sheep and goat in ability to retain nitrogen. Berseem hay fed ad libitum supported a daily gain of 742, 500, 71 and 31 g in young female buffaloes, cows, sheep and goats, respectively. Digestible CP values of 13·33, 13·47, 15·38 and 15·01% and TDN values of 59·8, 57·6, 70·4 and 77·6% were obtained for cow, buffalo, sheep and goat, respectively.
A method of including urea in whole grains
Authors: Ørskov E. R. , Smart R. , Mehrez A. Z. 
Published: March 2009

SUMMARYA method of including urea into whole grains is described. The whole grains were found to absorb completely a saturated solution of urea.The method gave the different cereals examined (barley, oats, wheat and maize) a homogeneouis distribution of urea and increased the voluntary intake of whole grains by lambs. The evolution of NH3in the rumen liquor was slightly slower when urea was absorbed into the grains than when it was included as urea crystals. The N content in the urea-treated grain was not changed after 6 months of storage.
The relation between animal gain and stocking rate: Derivation of the relation from the results of grazing trials
Authors: Jones R. J. , Sandland R. L. 
Published: March 2009

SUMMARYSeveral models have been proposed in the literature relating gain per animal (Ya) and stocking rate (x) from grazing experiments. Results from an experiment in which tropical pasture species were grazed continuously by beef cattle at a number of stocking rates (Jones, 1974) were used to examine this relation. A simple linear model of the form y = a − bxfitted the data well. Production per hectare (Yh) was related to stocking rate by yh = ax − bx2.Stocking rate for maximum gain per hectare (the optimum stocking rate) on each pasture could be calculated from the linear regression by a/2b.Data from a number of stocking rate experiments in tropical and temperate environments were examined to see if this relation held for a wider range of stocking rates and pasture types. Results were expressed on a common basis by calculating the optimum stocking rate and relating ratios of gain to ratios of stocking rate relative to that at the optimum.For gain per animal, the overall relation obtained: Ya = l·999–0·999x (r = –0·992; P < 0·001; n = 114) did not differ significantly from the expected linear relation: y = 2−x. Linearity was established over the range 0·18–2·0 times the optimum stocking rate. At rates greater than twice the optimum, animal gain was negative. When expressed as gain per hectare (Yh) the quadratic equation Yh = 2x − x2 gave a good fit to the data over this range.It is suggested that, since the relation between production per animal and stocking rate (animals/ha) remains linear over a wide range of stocking rates, two rates of stocking (with replication) may be adequate for grazing experiments and these would not have to span the optimum stocking rate in order to predict gain at the optimum stocking rate.
Effectiveness of some mechanical, thermal and chemical laboratory treatments on the drying rates of leaves and stem internodes of grass
Authors: Harris C. E. , Thaine R. , Sarisalo H. I. Marjatta 
Published: March 2009

SUMMARYDrying rates of stem internodes of S. 24 perennial ryegrass and S. 37 cocksfoot, some with leaf sheaths and laminae attached, were measured in controlled conditions of air speed, temperature and relative humidity after exposure for 60 sec to dry heat, steam, steam containing petroleum ether vapour, and petroleum ether vapour only. The last treatment was most effective in increasing the drying rate, but a similar effect was obtained by splitting the stem internodes longitudinally or by removing from the larger plant fragments (internodes with leaf) the leaf sheaths and laminae. Observations on leaves with a scanning electron microscope confirmed that the steam and petroleum treatments acted on the surface waxes thus reducing the cuticular resistance to water loss. The presence of internal tissue resistance was demonstrated by anaerobic treatment of ryegrass leaves and stem internodes to disrupt cell protoplasts. The ensuing increase in drying rate was clearest in stems which have a low surface area to volume ratio. The results suggest that the combination of both mechanical damage and thermal or chemical surface treatment could form the basis for more effective methods of increasing the drying rate in the field of crops cut for conservation.
Changes in growth habit of pigeon-peas (Cajanus cajan (L.) Millsp.) due to late sowing
Authors: Dahiya B. S. , Brar J. S. , Kaul J. N. 
Published: March 2009

SUMMARYThe habit of growth of pigeon-pea cultivars was greatly affected by environmental changes. The effect was greatest in the highest yielding cultivar, Pant A2, for the characters plant width, number of pods/main branch, number of pods/plant, grain yield and plant weight. In the late-sown crop the ‘vegetative sink’ was affected more than the ‘generative sink’. T21 was the outstanding yielder under late-sown conditions. It is suggested that a rotation of mungbean–pigeon pea–wheat can be grown in 1 year, with profitable returns.
The effect of quantity, source and time of application of nitrogen fertilizers on the yield and quality of Andropogon gayanus at Shika, Nigeria
Authors: Haggar R. J. 
Published: March 2009

SUMMARYExperiments made at Shika, Nigeria, over a period of 3 years showed that the drymatter response of Andropogon gayanus to applied N was curvilinear over the range 0–896 kg N/ha, with maximum yields being obtained at an application rate of about 500 kg N/ha. However, the highest return of dry matter per unit of fertilizer applied (14·4 kg D.M./kg N) occurred at 28 kg N/ha and there was only a modest increase in crude-protein content as N was increased, reaching a maximum of 10·5% at the highest level of N. Also, at both high and intermediate levels of N, A. gayanus was replaced by less desirable grasses.May, the beginning of the rainy season, was found to be the most efficient time to apply N, although reasonable dry-matter responses were obtained by applying N in the dry season. ‘Nitro-chalk’ and calcium nitrate were more efficient sources of N than urea, sodium nitrate and, in the long term, ammonium sulphate.
An analysis of factors contributing to the determination of saturation capacity in some tropical soil types (With One text-figure.)
Authors: Turner P. E. 
Published: March 2009

The limitations of the “constant” saturation capacity as a factor in the characterisation of types of soils, rather than individual soils, are discussed. An attempt has been made to overcome these limitations by distinguishing between the contributions made to saturation capacity by the organic and inorganic colloidal components of three widely different tropical soil types.1. Numerical evidence is given which shows that saturation capacity is very closely related to the content of clay and organic matter of soil (irrespective of the proportions in which they are present), but not to the fine silt fraction. Nevertheless, the correlation between saturation capacity and (a) organic matter, and (b) clay, is significantly greater for the tropical type containing the smallest amounts of these components than for the type containing the largest amounts.
Development, structure and seasonal change in the fleeces of unimproved Scottish Blackface sheep from the Hebrides
Authors: Ryder M. L. 
Published: March 2009

SUMMARYDetails are given of the fleece and other characteristics of three rams and three ewes of a strain that has lived feral on the island of Boreray in the St Kilda group since 1930.The animals are horned and short-tailed, the rams are about 60 cm high at the withers and weigh about 45 kg at maturity, while the ewes weigh between 25 and 30 kg and are 55 cm high. The ewes reached their maximum weight after 1 year, but the rams increased in weight during the 3 years under observation.The fleeces were shorter and finer than those of the modern Blackface, tending to have kemps rather than hairy heterotype fibres. The fleece weight was 1·25 kg, staple length ranged from 75 to 150 mm and mean fibre diameters ranged from 23 to 32 μm.Variable fleece casting occurred although no more than about 80% of both the primary and secondary follicles became inactive during the winter. Unlike other primitive breeds studied there was a relatively narrow peak of follicle inactivity in midwinter, although in the ewes this tended to occur later in the winter, as observed in improved breeds.There was a subsidiary small peak of follicle inactivity in August corresponding to the primitive shedding of the summer coat. Maximum fibre medullation occurred in June, and there was a second smaller peak in September.As in other primitive breeds a relatively high proportion of follicles lacked fibres at birth, but this retardation of development was no longer evident by 14 days when the usual peak in medullation occurred. More fibre shedding was observed at 56 days than in the modern Blackface. The fibre type arrays were of Plateau P1 type.
The clearance rate of rumen liquid and rumen fermentation pattern in sheep receiving forage diets
Authors: Thomas P. C. , Hodgson J. C. 
Published: March 2009

SUMMARYAn experiment was carried out to study the composition of the mixture of rumen short-chain fatty acids and the clearance rate of the rumen liquid phase in sheep given diets of dried grass, high-nitrogen hay, low-nitrogen hay and barley straw. Differences between diets in clearance rate were not significant (P > 0·05) and differences between diets in the composition of the mixture of rumen acids were small. There were substantial variations in clearance rate between individual sheep but this was not associated with variations in the pattern of fermentation and the correlation between the proportion of propionic acid and the clearance rate in the rumen was low (r = –0·23).In a second experiment sheep receiving a moderate-quality hay were given intravenous injections of atropine sulphate which resulted in significant increases in rumen volume (P < 0·01) and significant reductions in ruminal clearance rate (P < 0·05). These were accompanied by significant increases in the numbers of protozoa (P < 0·05) and bacteria (P < 0·05) in the rumen but the composition of the mixture of rumen short-chain fatty acids was unchanged.It is concluded that there is little possibility through alteration of ruminal clearance rate, for manipulation of rumen fermentation pattern in sheep receiving diets of moderate- or poor-quality forages.
Results from three cycles of six-course rotations on light land
Authors: Hanley F. , Ridgman W. J. 
Published: March 2009

SUMMARYA rotation experiment comparing the effects of length, type and management of leys on three test crops in six-course rotations during three cycles is described and the results discussed.Although the yields of the test crops varied from cycle to cycle there were no clear-out trends to suggest that the yield improves or deteriorates as time goes on with these particular rotations; the full benefit of the leys was obtained in the first cycle.The yield of potatoes immediately following the leys was no greater than the yield in an all-arable rotation receiving adequate nitrogen fertilizer, but the yields of two, barley crops following the potatoes were less in the all-arable rotation than in ley rotations even when 58 kg N/ha/year and 38t dung/ha/cycle had been applied and trefoil ploughed-in in the all-arable rotation. Rotations containing lucerne or lucernecocksfoot leys gave their greatest yields of potatoes and of barley following potatoes without any applied nitrogen fertilizer, but in the second barley crop showed the same sort of nitrogen responses as the all-arable rotation.Yield data were also obtained on the leys themselves in each cycle. These showed a decline from the first to third cycle in yield of broad red clover grown as 1-year leys and in that of 3-year leys which contained lucerne, both of which could be explained by the build-up of specific diseases. There were also changes in the effect of grazing compared with mowing on the yield of some leys but little change in the effects on leys of applying nitrogen to them. However there was no suggestion that these changes affected the arable crops that followed.
The growth and development of the alimentary tract in Asiatic swamp buffalo and zebu cattle
Authors: Moran J. B. , Wood J. T. 
Published: March 2009

SUMMARYThe weights of components of the alimentary tract were recorded in 55 swamp buffaloes and 51 zebu cattle slaughtered at Bogor in West Java. These were related to hot carcass weight (HCW) and slaughter live weight (SLW), the latter being calculated from locally developed regressions relating live weight to chest girth. Huxley's (1932) allometric equation was used in its logarithmic form as the basis for covariance analyses of the data. A stepwise regression analysis was also undertaken using a linear model relating HCW and gut component weight to species, sex, age and slaughter condition with SLW as the independent variable.There were significant differences in dressing percentage between buffaloes (38·1 %) and zebus (44·8%) at 340 kg SLW and these were due to species differences in full gut weight rather than weights of other non-carcass components. The allometric growth coefficients for total gut, or gut component, were generally higher in buffaloes than zebus, but the differences were not statistically significant. Together with other published data, these observations suggest that the gut contents may contribute more to the increase in live weight of buffaloes than in zebus.At the same SLW or HCW, the buffaloes had the heavier weights of full and empty total gut, full and empty reticulo-rumen and total gut contents. At the same total empty gut weight, buffaloes had the heavier empty reticulo-rumen. It was suggested that Indonesian swamp buffaloes and zebu cattle fed on village-type low-quality diets may also differ in the rate of development of their alimentary tract and this could have implications for their comparative nutritional physiology.
Adjustment for competition between varieties in plant breeding trials
Authors: Kempton R. A. 
Published: March 2009

SUMMARYA method is proposed for correcting for competition effects in yield trials by joint regression of plot yields on to the yields of neighbours. Estimation of the variety effects and competition coefficient along with tests of significance are described for a sugar-beet trial with single-row plots where competition effects are assumed to extend only to plants in immediately adjacent rows. For designs which are balanced for neighbouring varieties it is feasible to estimate separate varietal competition coefficients which may be partitioned into components for sensitivity and aggressiveness. An example is given of this extended model fitted to a competition diallel of seven species. While species differed in their sensitivity to competition there was no essential difference between inter- and intra-species behaviour. The model is used to assess comparative varietal performance in monocultures from performance in small plot trials.(Note that the general term ‘variety’ is used throughout this paper to refer to progenies at any stage in a selection programme.)
The effects of the growth-regulating compounds methyl decanoate and 2, 3, 5-triiodobenzoic acid on potato tuber size
Authors: Wurr D. C. E. 
Published: March 2009

SummaryApplication of methyl decanoate to a potato crop about the time of tuber initiation reduced the total yield and the yield of tubers in the grade 2·5–5·5 cm though neither of these reductions were significant. However, application of 2,3,5-triiodobenzoic acid increased the yield of tubers 2·5–5·5 cm by up to 20% while having no significant effect on total tuber yield. This change in the tuber size distribution was due to a more even partition of photosynthate between tubers and not to an increase in the total number of tubers.
Equations to predict the leaching of nitrate uniformly incorporated to a known depth or uniformly distributed throughout a soil profile
Authors: Burns I. G. 
Published: March 2009

SummaryEquations to predict the leaching of nitrate either uniformly incorporated to a known depth or uniformly distributed in field soils can be reduced to the approximate form:where f is the fraction of nitrate leached below h cm in a soil of field capacity Vm (% by volume) after P cm of drainage has passed through the profile. If nitrate is initially incorporated uniformly to a depth of w cm, then x = h – ½w(where h ≥ w); if nitrate is distributed uniformly throughout the whole profile, then x = ½h. For surface-applied nitrate x = h (Burns, 1975).Observed mean displacements in published experiments have been compared with predictions from the equations and from equations in which the mean movement of nitrate and water are assumed equal. The new equations give better agreement with the observed data.
Selection for seedling vigour in Festuca arundinacea
Authors: Faulkner J. S. , Johnston Fiona , McAneney D. M. P. 
Published: March 2009

SUMMARYTwo sets of experiments were carried out to compare methods of selecting Festuca arundinacea (tall fescue) for improved seedling vigour.In the first, germination and seedling growth of four varieties (Goar, Lironde, S. 170, and ZW 42–6) were compared in hydroponic growth tanks. From each variety, groups of seedlings were selected for each of four vigour characters (speed of germination, leaf length, root length and speed of production of the second leaf) and a fifth group was selected at random as a control. Plants of each group were intercrossed in isolation and their progeny compared.In the second, S. 170 was studied through two cycles of selection in a soil-based compost. In the first cycle, groups of seedlings were selected for each of five characters (speed of emergence, leaf length, and speed of production of the second leaf, first axillary tiller and coleoptile tiller). Two further groups were selected randomly. In the second cycle, the progeny of each group were reselected for the same character as their parents. Both first- and second-cycle progeny were compared among themselves.Significant direct responses to selection were obtained in all characters except speed of germination in hydroponics. Indirect responses also occurred but were mostly smaller and in response to selection for a related character, e.g. selection for early tillering resulted in early second leaves and vice versa. Two cycles of selection raised the frequency of coleoptile tillers from about 5 to 55 %, but the concomitant advances in vigour characters were smaller than those achieved by direct selection. It is argued that for practical purposes the basic criterion in selecting for improved seedling vigour should be rapid attainment of a particular growth stage such as appearance of the first tiller. Since speed of emergence itself responded to selection, the attainment of such a stage should be related to date of sowing rather than of emergence or germination.In the progeny of the hydroponic selections, all characters showed significant varietal differences, some of them the reverse of differences between the parent populations of the varieties. These results illustrated the importance of seed provenance as a determinant of seedling vigour, and suggest that choice of parent material is important in breeding for improved vigour.