bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nutritive value of lucerne. I. Preliminary studies of yield, composition and nutritive value (Season 1932)
Authors: Woodman H. E. 
Published: March 2009

SummaryThe main object of the present investigation (season 1932) has been to secure as much information as possible concerning yield, composition and nutritive value from crops of lucerne already established in several different localities. This work may be considered as preliminary to the more systematic investigations which have been designed to begin in the season 1933.The 1932 investigation comprised work on the following crops: (1) 4-year-old lucerne (variety Provence) grown on the Howe Hill University Farm at Cambridge. (2) 1-year-old lucerne (variety Provence) grown at Willingham, Cambridgeshire. (3) 1-year-old lucerne (variety Hungarian) grown on the Gravel Hill University Farm, Cambridge. (4) 4-year-old lucerne (variety Provence) grown at Tunstall, Suffolk. The season was characterised by its cold, wet, late spring and the prevalence of droughty conditions in June.
Wool characters in “half-bred” sheep (Border Leicester Rams x Cheviot Ewes) (With Plate V and five text-figures.)
Authors: Nichols J. E. 
Published: March 2009

SummaryData from the laboratory examination of fleece samples from representative animals of the parental Border Leicester and Cheviot stock, the F1 “half-breds” and the F2 ewes, are submitted.The characters of mean fibre length, fineness and mean fibre volume are discussed, the variability found in the various types being particularly noted. The distributions of fibre lengths are also considered, it being found that all the parental forms also appear in the succeeding generations.Evidence of blending inheritance is not manifest in the results, which support the interpretation of multiple factors as responsible for the expression of the wool characters of length and fineness.Attention is called to the importance of considering fibre volumes as criteria of follicle activity.
Rapid, plant-conserving estimation of heat tolerance in plants
Authors: Onwueme I. C. 
Published: March 2009

SUMMARYTwo methods were developed for the rapid estimation of heat tolerance in plants using excised tissue pieces. The first method was a modification of the conductivity-bridge method and could yield results in less than 3 h. The second method combined plasmolysis with vital staining for the estimation of tissue injury following a regulated heat stress. This method was first developed and perfected using onion bulb epidermis tissue. It was later adapted for estimation of heat tolerance in intact tomato plants. Results from this method could be obtained within 1 h. The advantages and limitations of the two methods are compared and discussed.
Effect of season and previous seasonal fertilizer N application rates on the response of an S.24 perennial ryegrass/white clover sward to fertilizer N
Authors: Marsh R. , Gordon F. J. , Murdoch J. C. , Stevenson W. E. G. 
Published: March 2009

SummaryThe effect of season of harvest and previous seasonal applications of fertilizer N on the response of perennial ryegrass/white clover swards to pre-cut applications of fertilizer N was studied in three consecutive years on different sites. Herbage D.M. yield responded in a curvilinear manner to increased pre-cut N application rates. There was a tendency in all experiments for the marginal response of herbage D.M. to increased pre-cut N application rates to decrease as previous seasonal fertilizer N application rates increased. Although the effect of season of harvest on the response of herbage D.M. to pre-cut N application rates varied with site/years, it was concluded that the marginal response of herbage D.M. to pre-cut N application rate varies little throughout the greater part of the growing season. The exceptions to this are the very early and late harvests and swards that receive low supplies of N from the sward/soil complex. The results are discussed in relation to other published data and to their possible use in the control of the seasonal pattern and total seasonal supply of herbage D.M. for rotational grazing management systems.
The effect of interval between harvests and nitrogen application on the digestibility and digestible yield and nitrogen content and yield of four ryegrass varieties in the first harvest year
Authors: Wilman D. , Droushiotis D. , Koocheki A. , Lwoga A. B. , Shim J. S. 
Published: March 2009

SummaryThe effect of six intervals between harvests and three levels of N application on digestibility, digestible yield and nitrogen content and yield was studied in four ryegrass(Lolium) varieties during a 30-week period in the first harvest year in a field experiment.Digestibility was higher with a 3-week than with a longer interval between harvests. Yield of digestible organic matter was increased by extending the interval from 3 to 6 weeks, but was slightly reduced by extending from 6 to 10 weeks.Increase in the level of applied N increased the degree of curvature downwards in the response to extending the interval in both yield of digestible organic matter and yield of N, supporting the view that N use should be accompanied by shortened intervals between harvests.Digestibility varied by up to 15 units D-value from one time of the year to another with a constant interval between harvests. The highest values were in the spring. Autumn values were low in spite of a relatively high proportion of green leaf.During the period immediately following the main period of stem development, doubling the interval from 4 to 8 or from 5 to 10 weeks reduced digestibility by 10 units and reduced digestible yield by 22%.In the absence of applied N, the N yield of S. 321 was 31% greater than the average of S. 22, S. 23 and S. 24. However, the apparent recovery of applied N in S. 321 was much lower than in the other varieties.
Lodging studies in Lolium perenne grown for seed: 2. floret site utilization
Authors: Burbidge A. , Hebblethwaite P. D. , Ivins J. D. 
Published: March 2009

SummaryIn these experiments lodging not only decreased the number of seeds harvested, but also had an effect in determining which spikelets on the ear set most seed. These data have also shown that many more seeds are set than are harvested, even when the crop is not lodged. It is suggested that there is a lack of assimilate supply to fill the developing seeds, some of which abort, allowing the remainder to attain a viable seed weight. Mechanical support of the crop may increase the assimilate supply to the seed thus allowing seed further up the ear and spikelet to develop fully.
Lamb and milk production of a flock of dairy ewes under an accelerated breeding regime
Authors: Eyal E. , Lawi A. , Folman Y. , Morag M. 
Published: March 2009

SummaryThe management of an experimental flock of dairy sheep was changed from a onceyearly to a frequent-lambing regime. Results are reported on the performance of the flock under the new regime in the course of 3 years. There were 53 and 160, 46 and 242, and 70 and 237 Awassi and Assaf (East-Friesian x Awassi) ewes, respectively, in the flock at the beginning of the 3 consecutive years. A breeding calendar was adopted to produce four mating seasons each year, namely June–July; September–October; December–January; March–April.Average annual production was 1·16 ± 0·24 lambs and 209±9 kg milk for Awassi ewes, and 2·07 ± 0·20 lambs and 287 ± 19 kg milk for Assaf ewes. Hoggets of the same breeds produced 0·61 ± 0·14 and 1·23 ± 0·10 lambs and 99 ± 37 and 220 ± 21 kg of milk, respectively.Following the February-March lambing, conception rates of hormone-treated ewes weaned 2 or 70 days post-partum were 57·1 and 48·8% respectively (P < 0·10). There were no differences in the length of the post-partum interval to conception between low and high milk-yielding ewes. Fertility was highest in the September–October and December–January mating periods, intermediate in June–July and lowest in March–April.Twenty-seven per cent of the original 126 mature Assaf ewes and 15% of the original 46 mature Awassis remained in the flock at the end of 3 years for further breeding. Thirty-one per cent of the mature Assaf population (mixed ages) and 21% of the hoggets were culled in the course of 3 years due to failure to conceive within 6 months post-partum. With Awassi ewes the rate of failure was much higher.Ewes which had lambed twice and completed, on average, 1·5 lactations in a year, produced 30% more milk per year than those which lambed only once during the same period. The more frequent lambing resulted in shorter lactations (156 days) and lower average daily milk yields (1·27 kg) compared with the 182 days and 1·41 kg in the less frequently lambing groups. Pregnancy during early stages of lactation had a small but significant (P < 0·05) effect on the concurrent lactation. Shortening the breeding interval had a much more marked effect on the subsequent lactation. Ewes that conceived, on average, 120 days post-partum, in the subsequent lactations produced 17% more milk than those conceiving 60 days post-partum (P <0·02).Ewes gaining weight at a rate of 5–7 kg during the first 2 months of pregnancy produced, on average, 0·27 kg less milk per day than those which either lost or maintained their weight in that period (P < 0·01).
A seedling test for cold hardiness in Lolium perenne L.
Authors: Fuller M. P. , Eagles C. F. 
Published: March 2009

SummaryA seedling test for measuring cold hardiness in Lolium perenne cultivars is described. Seedling performances of the cultivars in this test were closely related to those of mature plants in an artificial freezing test and to reported survival under field conditions in U.K. winters.With two-leaf seedlings it was possible to analyse hardiness into leaf damage, regrowth and plant kill enabling an index of hardiness to be compounded. Using this index in conjunction with lethal dose 50% estimates, meaningful separation of cultivars was possible.The possible application of this technique for screening breeding material and for detailed physiological work is discussed.
Formic acid as a desiccant for grass leaves
Authors: Thaine R. , Harris C. E. 
Published: March 2009

SummaryDetached, fully turgid leaves of S. 24 perennial ryegrass were sprayed with 1, 3 and 5 mg of a solution of 85% formic acid per leaf and dried in controlled conditions (temperature 28 ± 1 °C, relative humidity 22 and 64%, air speed 40 cm/s). The lowest rate of application increased the rate of leaf drying approximately four times when the relative humidity was 64%. Increasing the rate of formic acid or reducing the relative humidity to 22% did not enhance the drying further. The mode of action of formic acid is discussed. It is suggested that formic acid might be utilized to obtain quicker drying of grass for hay, and further investigations are called for.
Wool growth as affected by nutrition and by climatic factors
Authors: Coop I. E. 
Published: March 2009

The weight, length and quality (fineness) of wool produced at different times of the year and under different nutritional conditions has been determined over a period of three years by clipping at monthly intervals the wool grown on delineated skin areas of sheep. The treatments consisted of(a) wet ewes, grazing on pasture all the year, subjected to high and low levels of feeding during the ‘dry’, pregnancy and lactation periods;(b) dry ewes and lambs fed differentially on grazing during the winter and spring;(c) wet ewes fed in stalls on a diet of constant composition at rates sufficient to maintain constant effective body weight (i.e. making allowance for pregnancy increase and fleece weight increase). A small number of these ewes was also subjected to increased environmental temperature during the winter.The experiments have shown the existence of a marked seasonal rhythm in wool growth having a maximum in January (midsummer) and a minimum in July (midwinter). Changes in weight of wool grown are caused by sympathetic changes in both length and diameter. At the same level of feeding the rate of wool growth in midwinter is about onethird of that in midsummer.The nutritional demands of pregnancy reduce the rate of wool growth in winter and those of lactation delay the rise in production in spring. Nutrition also plays an important part in determining the time of the maximum and minimum. In dry sheep the maximum tends to occur before midsummer when pasture growth is at its best, but lactation in wet sheep prevents the expression of a maximum early in the summer, so that in these ewes it generally occurs after weaning, and therefore after midsummer. The level of nutrition also determines within limits the magnitude of the maximum and minimum.The fundamental cause of the seasonal rhythm of wool growth remains obscure. Nutrition, pregnancy and lactation can modify the rhythm, but it exists strongly even when variations due to these are eliminated. The seasonal rhythm of solar radiation has recently been shown to influence rate of wool growth, particularly during winter, and though this is undoubtedly one factor it is not the only one. Temperature has been suggested elsewhere as a possible cause, but the experiments described do not support the theory that environmental temperature has any direct effect on wool growth. It is suggested, however, that the seasonal rhythm of temperature may be a second factor.
Effect of plant population on growth and yield of soya bean(Glycine max)
Authors: Enyi B. A. C. 
Published: March 2009

SummaryIn soya beans (var. 3H55F4/149/1) grown in Tanzania, the total dry matter per plant, pod weight/stem weight, shelling percentage, number of nodes per plant, number of pods per plant, percentage number of nodes with pods, number of filled pods per plant, number of branches per plant, and grain weight from side branches decreased with increase in plant density from 74 to 111, 222, and 444 thousand plants per hectare. Grain yield per hectare decreased by 38, 51, and 72% respectively with the increases in plant population, but yield of total dry matter per hectare showed a significant increase with density. Crop growth rate increased with increasing leaf area, which in turn increased with increasing plant density. Relative growth rate, however, decreased with rising population. Over the range of the densities studied grain yield was positively related to number of side branches but negatively related to dry-matter production, leaf area duration and percentage of light intercepted. The proportion of dry matter accumulated in the pods and side branches decreased with increase in population, whereas the proportion accumulated in the main stem increased. Light seems to be the major factor controlling grain yield in this variety of soya bean, low light intensity under the plant leading to a reduction in the number of side branches, number of pods per plant and number of nodes with pods.
Response of cow pea (Vigna unguiculata L.) to CO2 enrichment environment on growth, dry-matter production and yield components at different stages of vegetative and reproductive growth
Authors: Bhattacharya Sheila , Bhattacharya N. C. , Biswas P. K. , Strain B. R. 
Published: March 2009

SUMMARYThis study examines the effects of increased atmospheric carbon dioxide concentrations on vegetative and reproductive growth and partitioning of biomass during pod and seed development of cow pea in controlled environment chambers at 350, 675, and 1000μl CO2/l.The length of main stem and branches, the number of leaves and branches, and leaf area were all greater at high CO2 than at low CO2 concentration. The appearance of flowers was 10–12 days earlier in high CO2 than in ambient CO2 atmosphere. The senescence of leaves started about 7 days earlier in plants grown at 675 and 1000 μl CO2/l than in those grown at 350 μl CO2/l. The rate of leaf senescence was more rapid in 1000 μl/l than in 675 μl CO2/l. The dry weight of roots, stems and leaves increased with CO2 enrichment, being greater in 675 μl/l than in 1000 μl CO2/l. Plants grown in 675 and 1000 μ1/1 produced more pods and seeds than in 350 μl CO2/l. Total seed weight and number of pods, as well as number of seeds per pod, were significantly greater in CO2 enriched atmosphere than ambient CO2 level. Although CO2 enrichment caused a significant increase in the total number and weight of seeds as well as pods, it did not affect the ratio of seed dry weight to the total dry weight of above-ground plant parts (harvest index). It is concluded from the present investigation that CO2 enrichment significantly enhanced vegetative as well as reproductive growth resulting in the increase in yield and early plant maturation in this leguminous crop.
Water and nitrogen management in wheat-lentil intercropping system under late-sown conditions
Authors: Ahlawat I. P. S. , Singh A. , Sharma R. P. 
Published: March 2009

SUMMARYExperiments comprising various ratios of wheat and lentil in a mixed cropping system under two irrigation regimes and three levels of N application are described and the results discussed. In all experiments the highest yield of grain was obtained by growing wheat alone and the highest yield of lentil grain by growing lentil alone. No mixture could equal the yield obtained by wheat alone.
Seasonal effects on the growth and time to maturity of lettuce
Authors: Gray D. , Morris G. E. L. 
Published: March 2009

SummaryThe increase in dry weight of field lettuce from sowings made between March and August in 1973 and 1974 started exponentially but this did not persist throughout growth. Departures from exponential growth were most marked in the 10 days of growth prior to maturity and a logistic rather than an exponential curve gave a better overall fit to the data. The rates of increase in plant dry weight were similar from all sowings made between mid-May and early to mid-July, when air temperatures and total radiation during the growth period of these crops exceeded 11–12 °C and 250 mWh/cm2, respectively. Sowings made earlier than mid-May took longer to mature and in 1973 gave crops with lighter heads. Quadratic regressions of harvest date on sowing date gave good fits to data obtained in different years at different sites but separate equations were required for each site.
Visual estimation of plant water status in cereals
Authors: Jones H. G. 
Published: March 2009

SummaryThe potential offered for plant breeding programmes by visual scoring techniques for plant water status was investigated in rice and spring wheat. It was found that differing plant morphology could seriously bias visual estimates of leaf water potential, particularly in spring wheat. In spite of this problem, it was found that at least for rice, this type of approach may have potential in future breeding programmes where an estimate of leaf water status is required, such as those for drought tolerance, so long as a high intensity of selection is not necessary.
Foetal stunting in sheep: 1. The influence of maternal nutrition and high ambient temperature on the growth and proportions of Merino foetuses
Authors: Cartwright G. A. , Thwaites C. J. 
Published: March 2009

SummaryTwo experiments designed to compare lambs born to Merino ewes subjected to either nutritional deprivation or high ambient temperatures (diurnal: 8 h at 42·2 °C, 16 h at 32·2 °C) during the last two thirds of gestation are described.In Expt 1, lambs from ewes group-fed to maintain maternal body weight at high ambient temperature were lighter (P < 0·01) and had shorter metacarpal bones (P < 0·01) than those from ewes fed to either lose, maintain or gain weight at prevailing temperatures (– 2·0 °C to + 16·4 °C). The regression of metacarpal length on the cube-root of birth weight (‘linear equivalence’) was linear. Simple maternal under-nutrition was thus not indicated as a cause of foetal stunting in heat-stressed ewes, though the proportions of affected lambs closely resembled those of the nutritional dwarfs.In Expt 2, in which all ewes were individually fed, heat-stressed ewes fed ad libitum consumed 40% less feed and produced lambs which were markedly lighter than those from controls at prevailing temperatures. Other control ewes pair-fed at the level of intake of heat-stressed ewes gave birth to lambs of similar weight to those fed ad libitum. Thus, although feed intake was substantially reduced at high temperatures, the amounts actually eaten by heat-stressed ewes were sufficient to enable control ewes to produce lambs of normal weight. The relationships between birth weight and the weight of the adrenals, cerebellum, cerebrum, heart, kidneys, liver, spleen and thyroid were linear, irrespective of treatment, and as in Expt 1 metacarpal length was linearly related to the linear equivalence of birth weight. However, not all changes in body components were directly proportional to changes in the body as a whole, and heat-affected lambs were thus neither true miniatures nor achondroplastic dwarfs. Until these relationships are clarified it is suggested that ‘stunting’ is the most appropriate description of the influence of high ambient temperature on the sheep foetus.The findings are consistent with the suggestion that the adverse effects of high temperature arise from an extreme form of foetal undernutrition.
Exponential relation between sweat rate and skin temperature in hot climates
Authors: Gatenby Ruth M. 
Published: March 2009

SUMMARYThe sweat rates, skin and rectal temperatures and other components of the heat budgets of cattle were measured in Kenya and in England. Mean sweat rate (Ec) was more closely related to mean skin temperature (T8) than to rectal temperature. The results were described by an exponential relationship between T8, (°C) and Ec (mg/m2.sec) of the form Ee = E0 exp (T8, — T0)/B, where T0 and B are parameters (both with units of °C) which describe the sweating response of the animal, and E0 is 1 mg/m2.sec. T0 was 30·8 °C for a single Bos taurus in England and 33·8 °C for five animals in Kenya suggesting that chronic acclimatization to a hot environment resulted in the cattle being able to tolerate a higher mean skin temperature. The effect of species (Bos indicus cf. B. taurus) was small compared with the effect of acclimatization, although the mean value of B was significantly higher for B. indicus (1·58 cf. 0·94 °C) indicating that the physiological mechanism controlling sweat rate in B. indicus was less sensitive to skin temperature.
The utilization of maize silage for intensive beef production: 3. Nitrogen and acidity as factors affecting the nutritive value of ensiled maize
Authors: Thomas C. , Wilkinson J. M. 
Published: March 2009

SUMMARYTwelve rumen-fistulated British Friesian castrated male calves, initially three months of age and 77 kg live weight (LW) were fed, both ad libitum and at a restricted level of 21 g organic matter (OM)/kg LW, on either maize silage (26% dry matter, 8.6% crude protein in D.M.) alone or with 2% of urea in the silage D.M., added at the time of feeding. At each level of urea (0 or 2%) silage pH was either increased to pH 5·45 by the addition of sodium bicarbonate, or left unchanged (pH 3·95) in a change-over design within each urea level. Addition of urea increased voluntary silage D.M. intake by 8% (P < 0·05) and partial neutralization increased consumption by 12% (P < 0·01). However, the response to urea only occurred when the silage was partially neutralized.At restricted intake, addition of urea increased rumen ammonia nitrogen from 3·17 to 13·41 mg/100 ml (P < 0·001) and blood urea nitrogen from 2·20 to 10·06 mg/100 ml (P < 0·001). There was no significant effect of addition of urea or of bicarbonate on rumen pH, VFA concentration or energy digestibility. However, the addition of urea significantly increased N retention (P < 0·01). Partial neutralization of silage was associated with an increase in venous blood pH from 7·366 to 7·396 (P < 0·001), and urine pH from 7·43 to 8·42 (P < 0·001).It is suggested that both low nitrogen content and acidity limit the nutritive value of ensiled maize, and that the effects of addition of urea and of partial neutralization may be metabolic rather than ruminal.