bluuebunny/crossref_metadata_2025 huggingface dataset:
Absorption of glucose by lamb proximal colon measured during early postnatal development
Authors: Smith M. W. , James P. S.
Published: March 2009

Pieces of proximal colon taken from lambs during the first 2 weeks of postnatal life were incubated in vitro for measurement of short-circuit current and unidirectional glucose fluxes.

The short-circuit current of colons taken from newborn and 1-day-old lambs was increased significantly in the presence of 5 mM D-glucose. This is taken as evidence for the presence of an active transport system for monosaccharides in this tissue. No such effect was seen using colons taken from 2-week-old lambs.

Direct measurement of glucose transport showed a net absorption to take place across the proximal colon of newborn and 1-day-old lambs. There was no net movement across colons taken from lambs aged 1 week and over. Essentially similar results were obtained when measuring the amount of glucose influx inhibited by 10−5 M phloridzin.

Colonic decline of glucose transport follows a time course different from that reported previously for the small intestine. It probably arises from rapid maturation of the colonic mucosa postnatally rather than from any gradual absence of substrate occurring during rumen development.
Utility of Rhizobium in the phyllosphere of crop plants in nitrogen-free sand culture
Authors: Nandi A. S. , Sengupta B. , Sen S. P.
Published: March 2009

Soya bean, mung bean, Bengal gram and lentil grown in nitrogenless sand culture and sprayed with suspensions of different strains ofRhizobiumshowed increases in dry weight, chlorophyll and N-content. In a few cases the performance ofRhizobiumapplied to the phyllosphere was almost as good as a seed inoculation treatment. The beneficial effect of sprayingRhizobiumstrains was independent of the specificity of cross-inoculation groups. Nitrogenase activity as indicated by acetylene reduction by theRhizooium-leafassociation varied between 460 and 723 nmol/g leaf/h.
Variation of leaf angle and incidence of rice blast disease
Authors: Mohanty C. R. , Gangopadhyay S.
Published: March 2009

Blast, caused byPyricularia oryzaeCav., one of the major foliar diseases of rice, appears sometimes in a devastating form in the seedling stage. The angles subtended by leaves may affect the establishment of the pathogen. Ono (1965) observed that leaf angles of rice plants, among many other factors, influenced deposition of spores. Gangopadhyay & Chattopadhyay (1974) found that brown spot disease (Helminthosporium oryzae) incidence in rice increased with increase in leaf angles. The present study is intended to find out the role of leaf angles in rice on the incidence of blast disease at the seedling stage.
Investigations into the role of specific micro-organisms in the aerobic deterioration of maize silage
Authors: Woolford M. K. , Wilkie Ann C.
Published: March 2009

Two experiments were undertaken with maize silage, which had been sterilized by subjecting it to a 6 Mrad dose of γ radiation, inoculated with micro-organisms implicated in the aerobic deterioration of silage and subsequently exposed to air. The inocula employed comprised mixed strains of yeasts, bacilli and lactic acid bacteria and combinations of these. The changes which accompanied aerobic deterioration were observed. The major losses of fermentation acids, ethanol, ammonia and dry matter, and increases in total nitrogen and temperature were associated with inocula in which yeasts were represented. Similar changes of a lower magnitude were also observed in silage treated with inocula containing bacteria only, although these were not always accompanied by the growth of these organisms or loss of dry matter. However, when employed in mixed inocula with yeasts, the bacteria proliferated and tended in some instances to increase losses further, suggesting an association between the groups of micro-organisms in the aerobic deterioration process. Losses were also sustained in sterile silage which received no inoculum and the possible reasons for this are discussed.
The role of foliar fertilizers in tolerance of the cotton leafworm to certain insecticides
Authors: Moustafa Omayma K. , El Attal Z. M. , Doban Amal F.
Published: March 2009

Evaluation of some insecticides against nine strains of S. littoralis, selected with decamethrin and foliar fertilizers separately and their combinations for three successive generations, was conducted to elucidate the effects of fertilizers on the tolerance pattern. The results indicate that the selection with fertilizers induced a low level of tolerance to both cyolane and profenofos. The LC50 of chlorpyrifos for all fertilizers' strains was lower than that of the susceptible strain. The efficiency of cyolane and fenvalerate on strains developed by the selection with decamethrin-fertilizer combinations was remarkably increased. Since the selection with fertilizers has induced a tolerance to some insecticides such as cyolane and profenofos and as the efficiency of these insecticides was enhanced on strains developed by the pressure of decamethrinfertilizer combinations, it is preferable to use decamethrin simultaneously in admixture with foliar fertilizers for pest control.
The lactation performance of red deer on hill and improved species pastures
Authors: Loudon A. S. I. , Darroch A. D. , Milne J. A.
Published: March 2009

Three groups of red deer hinds of 9–10 years of age were grazed upon an indigenous hill pasture (A), an improved species grass sward (predominantly perennial ryegrass) maintained at < 1500 kg D.M./ha (B), and one maintained at 2000 kg D.M./ha (C) from immediately after calving on 29 May until weaning on 22 September. Numbers of hinds in each treatment were 8, 6 and 9 respectively. Milk yields of hinds were estimated on swards A and C by the calf-suckling technique and hind and calf live-weight changes and hind grazing behaviour were recorded on all three swards during lactation.

Hinds on award C yielded on average 60% more milk over the lactation period than hinds on sward A, day 40 yields being 2·2 and 1·5 kg/day respectively. Calf growth rates (treatment A, 257 ± 9·5, B, 324 ± 12·1 and C, 369 ± 14·5 g/day) were higher on the improved species sward than on the hill sward and higher on the improved sward with the greater herbage mass. On treatments A and C calf growth rates were significantly (P < 0·05, r = 0·69) correlated with milk yield throughout lactation. At weaning, calves on sward C were 7·5 and 4·5 kg heavier than those on swards A and B respectively. Biting rates were lower (33 v. 56 bites/min) and grazing times higher (11.7 v. 6.0 h) on sward A than swards B and C. The poorer performance of hinds and their calves on sward A was considered to be due to a lower quality of diet ingested, and to behavioural limitations on intake occurring when hinds graze indigenous swards of relatively high species diversity. These results are discussed in relation to the grazing behaviour of cattle and sheep on similar swards.

The significance of the results to red deer farming in the U.K. is briefly discussed.
Tillage under controlled conditions: its effect on emergence and yield of spring barley
Authors: Brown N. J. , North P. F.
Published: March 2009

Effects of controlled tillage and soil-water conditions at the time of cultivation on emergence and grain yield were measured for a spring barley crop grown on a silty clay loam soil. A range of soil densities was achieved using conventional implements (tine-cultivator and roller) in combination with three levels of soil wetness. Concrete tracks supported both tractor and implements to prevent compaction due to wheelings, and rain-activated mobile shelters excluded precipitation from the field site.

Tillage treatments had large and significant effects on plant establishment. Both rate of emergence and final emergence were lowest where the soil was rolled at a high moisture content, and greatest where it was cultivated dry. Time for 50% plant emergence, rate of emergence and final plant population density all tended to be linearly correlated with the bulk density of the prepared seed bed. Despite large differences in plant establishment, later compensatory growth caused final yields of grain to show no significant response to tillage treatment.
Varietal response to rhizobial strains for nodule character, chlorophyll and protein content in green gram (Vigna radiata)
Authors: Prasad J. , Ram H.
Published: March 2009

The formation of effective nodules by rhizobial strains is influenced by both the host and the environment (Gibson, 1977). The interaction between host genotype and strains of Rhizobium sp. has already been established for some species (Gasser et al. 1972; Rai & Singh, 1979). The present study presents data for the contribution of different rhizobial strains to nodulation character and quality of green gram.
Metabbolism of perfused ruminant muscle
Authors: Coward B. Jane , Buttery P. J.
Published: March 2009

Substrate and nitrogen metabolism of ruminant muscle was studiedin vitrousing a perfused sheep hemidiaphragm preparation. Glucose, acetate, propionate and butyrate were taken up by the perfused muscle at a constant rate over 2 h. Rate of acetoacetate uptake declined over the perfusion period. Net production of 3-hydroxybutyrate over the perfusion period was observed.

Release of alanine and glycine by the perfused muscle could not be accounted for by protein breakdown, implicating muscle as a site of synthesis of these amino acids. The perfused muscle metabolized aspartate and arginine to a considerable extent, but the branched-chain amino acids only to a small extent. Only a small proportion, approximately 5%, of the alanine produced by the perfused muscle was derived from glucose.

In the presence of amino acids, at twice the concentration found in plasma, and insulin, some amino acids showed a net uptake by the diaphragm but when cysteine was omitted from the perfusate, all amino acids with the exception of arginine showed a net output. Evidence was obtained that protein synthesis was reduced in the absence of cysteine. The output of Nτ methylhistidine by the preparation was much higher than could be accounted for by estimates of protein breakdown using isotope dilution techniques. These data are, however, consistent with the view that Nτ methylhistidine is not a good index of muscle protein breakdown in sheep.
Effect of root zone temperature on early growth, nodulation and nitrogen fixation in soya beans
Authors: Matthews D. J. , Hayes P.
Published: March 2009

Soya-bean plants were grown for 40 days in a range of root temperatures from 10 to 25°C either in a root medium containing N but uninoculated or in a N-free medium but inoculated withRhizobium japonicum. Low root temperature restricted growth in both cases but the plants depending solely on symbiotic N-fixation were much more affected. At 10 CC root temperature plants failed to nodulate but both nodulation and nitrogen fixation increased greatly in the range 15–25°C. It is concluded that soya beans sown in cool soils would benefit from applied nitrogen at sowing time.
Towards more efficient soil-water modelling: moisture profiles for constant application or removal of water at the surface
Authors: Towner G. D.
Published: March 2009

Soil-water profiles are often calculated using models based on the application to successive soil layers of an approximate formulation of Darcy's Law. An arbitrary decision is usually made concerning the magnitude of the layer thickness, Δz, and time increment Δt, a decision often based on the intuitive criterion that both should be as small as possible. An unsuitable choice can either give rise to oscillations in the solutions that can be eliminated only by recalculation using different increments, or can culminate in an accuracy unjustified by the precision of the data, both cases resulting in unnecessarily lengthy and wasteful computing. However, mathematicians have shown, for problems which are analogous to particular soil-water models, that oscillations will not occur if τ = D(Δt)/(Δz)2 ≥ 0·50 (where D is the soil-water diffusion coefficient, assumed constant).

This paper considers the development of moisture profiles in soils with a constant rate of loss (e.g. evaporation) or entry (e.g. irrigation) of water imposed at the surface, and demonstrates that the criterion τ ≥ 0·50 can be extended to apply to waterdependent diffusion coefficients by re-interpreting D as the maximum value occurring in the profile. Examples for 10-layer models suggest that it is sufficient for practical purposes to start with Δt values that give τ-values close to 0·50, and to proceed to smaller Δt-values only when necessary. The total gain or loss of water given by integrating the calculated profiles is compared with the known amount entering or leaving at the surface.

The profiles for both evaporation and irrigation are found to advance too rapidly.
The influence of stage of growth, closeness of defoliation, and moisture on the growth and productivity of a ryegrass–white clover sward:I. Effect on herbage yields
Authors: Appadurai R. R. , Holmes W.
Published: March 2009

1. An experiment was conducted in 1959 and 1960 on a rye-grass-white clover sward under a ventilated Dutch light structure to study the influence of the following treatments in all combinations. Cutting to within 1 in. or within 3 in. of ground level, cutting six times per year as for grazing or four times a year as for silage, applying water to restore the soil to field capacity (a) when the soil moisture tension at 1 ft. depth reached 10 cm. Hg, or (6) when the soil moisture tension at 1 ft. reached 50 cm, Hg, or (c) once only in the growing season. Observations were made on the effect of the treatments on the yield and seasonal distribution of herbage dry matter, the clover content, the crude-protein and crude-fibre content, and the root weights.
The evaluation of artificially dried grass as a source of energy for sheep:I. The effect of stage of maturity on the apparent digestibility of rye-grass, cocksfoot and timothy
Authors: Waite R. , Johnston Margaret J. , Armstrong D. G.
Published: March 2009

1. Three species of grass, rye-grass (two varieties, S 23 and S 24) cocksfoot (variety S 37) and timothy (variety S 48) were cut at various stages of maturity, dried and given at several planes of nutrition to sheep in respiration chambers. The detailed chemical composition of the grasses and the apparent digestibility of the constituents were studied.
Effect of pasture growth rate on live-weight gain of grazing beef cattle
Authors: Ebersohn J. P. , Moir K. W.
Published: March 2009

Live-weight gain of beef cattle grazing all-grass or grass-clover pastures, details of which have been reported previously, was significantly (P < 0·01) correlated with pasture growth rate, but not with pasture dry matter on offer (either total or green), or with dietary-energy concentration. From ideas generated from the relationship between live-weight gain and pasture growth rate, and using intake values measured from the number and size of prehension bites, it is shown how high live-weight gain for measured dietary-energy concentration could be explained by differential contribution to digestibility and voluntary intake from pasture new growth.
Histochemical localization of enzymes of various metabolic pathways in the testes of buffaloes, goats and rams
Authors: Bilaspuri G. S. , Guraya S. S.
Published: March 2009

Isocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), β-hydroxybutyrate dehydrogenase (β-OH-BDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) were histochemically located in the testes of buffaloes, goats and rams. The enzyme activities varied with the enzyme, species and cell type. The activities in the seminiferous tubules were correlated with the stages of seminiferous epithelial cycle (SEC). During this cycle, the activities in the Sertoli cells, spermatogonia and spermatocytes remained unaltered in contrast to those in the spermatids. The activities of SDH, ICDH and MDH were relatively greater in buffalo, while goat and ram resembled each other quite closely. ICDH and MDH preferred NADP to NAD. In the three species, the activities of ICDH, SDH and MDH generally followed an increasing order. G-6-PDH was greater in the interstitial tissue of buffalo than in goat and ram; the maximum activity of this enzyme in each species was found in the spermatogonia. In comparison with G-6-PDH, GDH was less evident in the interstitial tissue of buffalo and goat; Sertoli cells and spermatogonia also showed relatively less MDH activity whereas the other germ cells may have relatively less, similar or more, GDH activity depending on the species. β-OHBDH activity was similar in the interstitial tissue of the three species, but in the seminiferous tubule, the activity was less in goat. But for GDH and β-OH-BDH which could show different results, the activities of other enzymes generally decreased from spermatogonia through spermatocytes to spermatids but increased during spermiogenesis. In spermatozoa, the enzymes were observed only in the mid-piece. The possible physiological significance of the results is discussed in relation to different metabolic pathways.
Some observations on phosphorus homoeostasis and requirements of sheep
Authors: Braithwaite G. D.
Published: March 2009

The results of phosphorus kinetic studies from 149 sheep used in previous studies of calcium and P metabolism have been analysed statistically, to provide information on the mechanism of control of P homoeostasis.

Whereas the rate of absorption of dietary P was increased in direct relation to P intake, the efficiency of absorption was decreased. Both the rate and efficiency of absorption, however, were increased in response to increased P demands. These results suggest that P may be absorbed by two processes: a passive one, related to P intake, and an active one, related to P demands.

Endogenous loss of P in the faeces was directly related to both P intake and P absorption but inversely related to P demands. Salivary secretion of P was directly related to P absorption and increased at a rate of 1 mg/day/kg body weight for each 1 mg/day/kg body weight increase in absorption. This finding supports the suggestion that the inevitable endogenous faecal loss of P, in animals fed exactly according to their P requirements, is not constant but varies in direct relation to the rate of P absorption, and hence to the P intake needed to supply these requirements.

Urinary loss of P was generally low, but high values were found in some animals and were associated with increased rates of P absorption and decreased rates of endogenous faecal loss of P. Possible reasons for these high rates of urinary P are discussed.

Increased P demands were met by a combination of an increase in P absorption and a decrease in endogenous faecal loss of P, and P retention was directly related to Ca retention.

The relevance of these results to the calculation of P requirements and to the control of P homoeostasis is discussed.
Effect of weight change on the performance of autumn-calving suckler cows
Authors: Chestnutt D. M. B.
Published: March 2009

Over a period of 3 years 18 autumn-calving, single suckled, April-weaned cows were stocked at three rates at pasture to gain 132, 70 or 25 kg (H, M and L respectively) between April and August and fed to lose 100, 54 or – 13 kg (H, M and L respectively) while housed between November and April, the relative total energy intake over winter being 0·64, 0·83 and 1·00 respectively. Milk yield was reduced by 2·68 kg/day on the H and 1·25 kg/day on the M treatment and as a result calves gained 37 and 10 kg less respectively over winter than on the L treatment. However, despite poorer calf performance economic considerations would indicate a preference for high weight gain during the grazing season and a corresponding loss over winter.
The effect of application of nitrogen fertilizer on the growth of opium poppy in north central India
Authors: Yadav R. L. , Mohan R. , Singh R. , Verma R. K.
Published: March 2009

In a 2-year field study conducted at Lucknow (26·5° N, 80·5° E and 120 m altitude), plant height, leaf area index, dry-matter accumulation and N uptake of opium poppy (Papaver somniferum L.) followed a sigmoid path. After attaining a peak of accumulation at 120 days, dry matter declined in plots given N fertilizer but remained static in the control. N application (50, 100, 150 and 200 kg/ha) increased the opium, seed and morphine yields compared with the control. Morphine concentration (%) in the opium, however, increased up to 100 kg N/ha and decreased when N doses exceeded that level. Divided application of N, i.e. half at sowing and remainder at the stem elongation stage, proved beneficial for opium, seed and morphine yields.
The selenium concentration of cereal grain and conserved and fresh herbage from farms in England and Wales
Authors: Heys Vivienne , Hill R.
Published: March 2009

The selenium concentration of cereal grain and herbage from 131 farms in England and Wales was, in general, low: the proportions of samples with values below 0·03 mg/kg D.M. were 60% for grain (primarily barley, from 96 farms) and 39% for conserved herbage (primarily hay, from 131 farms). Values for fresh herbage from 12 farms were similar to those for conserved herbage. There were no significant differences in selenium concentration among herbage species. For all samples, those from the Cambridge area contained more selenium than those from other parts of England and Wales.
Dormancy responses to post-harvest application of growth regulators inDioscoreaspecies: I. Responses of bulbils, tubers and tuber pieces of threeDioscoreaspecies
Authors: Wickham Lynda D. , Passam H. C. , Wilson L. A.
Published: March 2009

The effects on dormancy of post-harvest application of growth regulators to bulbils, tubers and tuber pieces of tropicalDioscoreaspecies were examined. Abscisic acid, kinetin, indole acetic acid and 2-chloroethyltrimethylammonium chloride were found to have little or no effect on either shoot or tuber-root production, while ethrel greatly promoted tuber-root production with little or no effect on shoot development. The germination of slices of tubers ofD. alatawas delayed by maleic hydrazide but there was no effect on intact tubers ofD. alataandD. esculenta. Treatment with 2,4-dichlorophenoxyacetic acid caused massive root and callus development along with delay in shoot development, while gibberellic acid occasioned marked extensions in the dormant period.
Studies on pH, number of protozoa and microbial ATP concentrations in rumen-incubated nylon bags with different pore sizes
Authors: Lindberg J. E. , Kaspersson A. , Ciszuk P.
Published: March 2009

A number of factors affect predictions of rumen degradability of feedingstuffs when using thein saccotechnique (Lindberg, 1983). One factor which exerts a great influence is the bag cloth aperture (Lindberg & Knutson, 1981; Lindberg & Varvikko, 1982). Without doubt part of the difference in degradation between pore sizes can be explained by differences in particulate matter losses (Lindberg & Knutsson, 1981; Lindberg & Varvikko, 1982). It has, however, also been suggested that the differences between pore sizes are due to the combined effect of differences in liquid exchange between the bags and the rumen contents and on the selection of microbes entering the bags (Lindberg & Varvikko, 1982).
The relationship of number and position of seeds to fruit size and curvature inCapsicum annuumL.
Authors: McArdle R. N.
Published: March 2009

Fruit curvature is a trait which has been little investigated by botanists and horticulturists. The degree to which a fruit is curved can be accounted for intuitively in cases where there are no physical barriers to normal fruit growth, such as obstruction by plant parts or the soil surface. The curvature of pendant, unobstructed fruit, as in the Solanaceae, has received limited discussion in the literature.
The effects of three protein sources on the growth and feed utilization of cattle fed cassava
Authors: Tudor G. D. , McGuigan K. R. , Norton B. W.
Published: March 2009

The nutritive value of diets predominantly of dried cassava (Manihot esculenta Crantz.) tubers supplemented with protein concentrates, and roughage were measured in three experiments using steers.

In Expt 1 the digestibility of diets of dried, chipped cassava tubers and tops (80:20) or rolled sorghum grain and cotton seed hulls (80:20), supplemented with 4 or 8% groundnut meal and urea, was determined. The apparent digestibility coefficients of organic matter (OM) of the cassava diets with 4 or 8 % groundnut meal (0·77 and 0·80, respectively) were significantly (P < 0·01) higher than grain diets with 4 or 8% groundnut meal (both 0·74). The digestibility of starch in the cassava diets was significantly (P < 0·01) higher than in the grain diets (1·00, 0·99, 0·94 and 0·93, respectively). There were no significant differences in the digestibility of the N component (0·62 and 0·61 v. 0·58 and 0·59, respectively). The N retained (g/day) was lower (P > 0·05) with cassava (7·8 and 6·8 v. 11·1 and 10·5, respectively) and was utilized (g/100 g apparently absorbed N) less efficiently (P > 0·05) (18 and IS v.28 and 27, respectively).

The high apparent digestibility of the cassava diet suggests that cassava could replace cereal grain in intensive finishing diets. The N retention data suggest that groundnut meal is no better than urea as a N source.

In Expt 2, 15 steers with a mean initial weight of 173 kg were individually fed pelleted diets of sorghum grain, cassava plus urea or cassava plus meat and bone meal (90 concentrate: 10 roughage). The cattle fed the grain diet ate significantly (P < 0·01) more OM (4·3 v. 3·4 kg/day), grew faster (P < 0·01) (1·21 v. 0·85 kg/day) and slightly more efficiently (P > 0·05) (3·6 v. 3·8 kg/kg) than cattle fed cassava with urea. Cattle fed cassava with meat and bone meal were intermediate between the two treatments for intake and daily gain (3·7 and 1·06 kg/day, respectively) but had the best feed conversion (3·5 kg/kg). The acetic/propionic acid ratio was similar on all three diets (1·2, 1·6 and 1·4:1, respectively), but the ratio of propionic/butyric was significantly (P < 0·01) different (5·8, 2·7 and 2·7:1, respectively).

In Expt 3, 15 other steers with mean initial weight of 195 kg were individually fed pelleted cassava diets with 0, 5 or 10% fishmeal (82 cassava: 18 roughage). The intake of OM (4·2, 4·5 and 4·7 kg/day, respectively), daily live-weight gain (0·98, 1·27 and 1·32 kg/day, respectively) and feed conversion (4·3, 3·7 and 3·7 kg/kg, respectively) were all better in cattle fed cassava with fishmeal. The proportions of volatile fatty acids in the rumen fluid were similar to that recorded in cassava fed cattle in the earlier trial.

It is concluded that cattle fed high energy diets based on dried cassava tubers can perform well. Although feed intake and daily gain of cattle fed cassava may be lower than for cattle fed grain diets, the conversion of food to live-weight gain should be similar or better.
Soil erosion in south Somerset
Authors: Colborne G. J. N. , Staines S. J.
Published: March 2009

Local soil erosion has long been a problem on very fine sandy and silty soils in south Somerset. Some 40 fields in arable use were chosen randomly and monitored monthly for erosion in the winter of 1982–3. Erosion was measured along fixed traverses and then compared with soil attributes, site factors and cultivation practices. Winter cereals were worst affected with a third of the fields having soil losses in excess of 4 m3/ha. There was least erosion on bare ploughed ground and moderate losses on cash root crops. Soil type, organic-carbon content, clay content, drill direction, wheeling density and slope all affected soil loss in winter cereal fields.

Erosion did not assume serious proportions until a combination of soil surface conditions and soil wetness allowed run-off to form rills. Only moderate falls of rain were then needed for widespread removal of soil. Preventative measures include grassing slope convexities, more grass in the rotation to improve soil organic matter and structure, avoiding wheelings, drilling across the slope and keeping headland widths to a minimum.
Some factors limiting the growth and yield of winter wheat and their variation in two seasons
Authors: Prew R. D. , Church B. M. , Dewar A. M. , Lacey J. , Magan N. , Penny A. , Plumb R. T. , Thorne Gillian N. , Todd A. D. , Williams T. D.
Published: March 2009

Multi-factorial experiments on winter wheat cv. Hustler in autumn 1979 and 1980 sown on a clay loam soil following potatoes tested the effects of combinations of the following eight factors, each at two levels: sowing date; amount of nitrogen; division of nitrogen; timing of nitrogen; irrigation; autumn pesticide (aldicarb); summer aphicide (pirimicarb); and fungicide (carbendazim, tridemorph, maneb and captafol).

The mean grain yields of all plots in 1980 and 1981 were respectively 9·6 and 8·3 t/ha; the best eight-plot means were 11·2 and 9·9 t/ha. Fungicides had the largest effect on grain yield, increasing it by 0·8 and 1·7 t/ha in 1980 and 1981, mainly by increasing grain size. Effects were greater with earlier sowing and the larger amount of nitrogen. Benefits from fungicide were well related to the control of leaf diseases, mainly Septoria spp., which became severe after anthesis. Fungicide temporarily decreased the number of saprophytic fungi on the developing ears. Aphids that appeared in autumn on plots sown in mid-September were controlled by autumn pesticide, which also prevented the spread of barley yellow dwarf virus that occurred only in 1981. Consequently, yield of early-sown plots in 1981 was increased by autumn pesticide, but only when the severe infection with leaf diseases was controlled by fungicide. Autumn pesticide decreased nematode populations. Aphid populations in summer were small and yield was unaffected by the decrease in numbers that followed application of an aphicide.

Sowing on 20 or 15 September, as compared with 19 or 30 October, caused faster growth and development and greater uptake of N from the soil early in the season. Effects were smaller after April: earlier sowing increased total dry weight by 2·5–3·0 t/ha and, when leaf diseases and barley yellow dwarf virus were controlled, increased yield by 0·9-l·0t/ha. Increasing the amount of N applied by 70 kg/ha (from 105 or 80), increased yield only in 1980 and then only when fungicide was used. Extra N decreased yield in 1981 in the absence of fungicide. Extra N always increased N uptake and decreased grain size. Applying mostor all of the Non 4 or 19 March instead of 15 or 23 April resulted in less uptake of N from anthesis onwards and smaller yield, especially in 1980. N in three applications instead of one had negligible effect. Trickle irrigation decreased yield slightly, despite delaying leaf senescence and increasing straw weight. Attributes of wheat on best yielding plots differed little between years. Average values were: 534 ears/m2; 40·7 grains/ear; 40·4 mg/grain; 18·8 t/ha total dry matter and 214 kg N/ha uptake by grain plus straw.
Time of sowing and the yield of winter wheat
Authors: Green C. F. , Ivins J. D.
Published: March 2009

Research conducted on sowing dates for wheat shows a trend towards increased yield as sowing is advanced (U.K.: Walker, 1980; Binghamet al.1983; the Netherlands: Darwinkel, Hag & Kuizenga, 1977; Canada: Nasset al.1975; Briggs & Aytenfisu, 1979). In a review of the influence of drilling time on winter wheat in the U.K. McLean (1981) suggested October planting as the optimum. However, sowing before this time often results in increased yield (Binghamet al.1983).
Post-partum intervals to oestrus and conception in Yankasa sheep
Authors: Osinowo O. A. , Ekpe Grace A.
Published: March 2009

The potential for twice-yearly lambings by tropical sheep is well recognized (Brown, Cameron & Ngere, 1972; Goode, Linnerud & Tugman, 1980; Osinowo, 1982). In order for ewes to lamb every 6 months the rebreeding interval must be 33 days or less. Factors affecting rebreeding in post-partum ewes have been reviewed (Hunter, 1968a,bVan Niekerk, 1979).
The effects of N fertilizer and soil moisture on the nodulation and growth ofPhaseolus vulgaris
Authors: Saito Siu M. T. , Montanheiro Maria Nazareth S. , Victoria R. L. , Reichardt K.
Published: March 2009

Soil water content affected the nodulation and N2fixation ofPhaseolus vulgarisbyRhizobium phaseoliand the utilization of mineral N by plants. Plants grown in wet soil produced twice as much as those grown on dry soils. Nodule weight and activity were five to ten times greater than those from dry soils. At 45 days, N additions inhibited nodulation, but this effect was partially diminished in wet soils.

The maximum N utilization from fertilizer to produce dry matter did not correspond to maximum N utilization by pods.
Effect of mechanical and chemical seed treatments on the number and size of seed tubers and yield of potatoes
Authors: Sekhon H. S. , Singh M.
Published: March 2009

Field experiments to study the effect of pre-sprouting, cutting seed and seed soaking in plant regulators on the number and size of seed tubers and yield of potatoes were conducted during the autumn crop seasons of 1978–9 to 1980–1. At the same seed rate, cut seed produced significantly more sprouts and stems, seed-size tubers and seed yield than the whole seed without affecting the aggregate yield. Similar effects were recorded with soaking whole non-dormant tubers in 10 mg GA 3/1 solution for 15 min before planting. Soaking whole non-dormant seed in 0·5% thiourea solution for 1 h increased the number of sprouts and seed-size tubers, giving increases in seed yield of 2·26, 2·73 and 2·65 t/ha over soaking seed in water in the three consecutive years. The corresponding increases in aggregate yield were 1·79, 1·48 and 1·60 t/ha. Soaking cut seed in solutions of 10 mg GA 3/1 and 0·5% thiourea singly or in combination had an adverse effect on the yield of potatoes.
Resistance in marrow (Cucurbita pepo L.) to different strains of cucumber mosaic virus
Authors: Pink D. A. C. , Walkey D. G. A.
Published: March 2009

Plants of the Cucurbita pepo L. cultivars Cinderella, Cobham Bush Green and Gold-rush were inoculated with six strains of cucumber mosaic virus (CMV) from different geographical areas and known to differ in pathogenicity and virulence. The cv. Cinderella showed high resistance to all strains, cv. Cobham Bush Green was moderately resistant and cv. Goldrush was highly susceptible particularly to the CMV–SEV strain which caused necrotic symptoms.
Mesenteric venous blood flow and the net absorption of glucose in sheep fed dried grass or ground maize-based diets
Authors: Janes A. N. , Parker D. S. , Weekes T. E. C. , Armstrong D. G.
Published: March 2009

A surgical procedure is described for placing a catheter in the mesenteric vein of sheep, such that blood draining the reticulo-rumen is not sampled. This catheter, together withothers in the mesenteric vein and carotid artery, was used to determine mesenteric blood flow and the net absorption of glucose in five sheep fed both dried grass and ground maize-based diets. The mean (± S.E.) mesenteric blood flow rates were 33 ±0·9 and 37 ± 5·7ml/min/kg live weight when fed the dried grass and maize-based diets respectively. These flow rates, together with the small venousarterial differences in plasma volatile fattyacid concentrations observed, indicated that the mesenteric catheter did not sample blood draining the reticulo-rumen in the conscious, fed animal. Further confirmation was provided by subsequent post-mortem examinations of the catheters. When fed the dried-grass diet, a significant net absorption of glucose could not be detected. However, when fed the maize-based diet a net glucose absorption of 19·3 ± 0·75 mmol/h was observed.
Variation in development of wheat and barley in response to sowing date and variety
Authors: Kirby E. J. M. , Appleyard Margaret , Fellowes Gwynneth
Published: March 2009

A number of commercial varieties and advanced breeding lines of wheat and of barley were each sown successively in the field from early in September until late in February in 3 or 2 years. Shoot apex development was monitored throughout the growing season and the dates at which the double ridge stage and the terminal spikelet stage were attained are reported. There was considerable variation in the date at which these stages occurred, associated both with variety and date of sowing. When sown early, spring wheat varieties and the winter wheat, Fenman, developed more rapidly than the other winter wheats, but the difference disappeared in sowings made in the middle of October or later. Spring barley developed more quickly than winter barley and the difference persisted until sowings made in mid-November.

Length of the longest leaf sheath, number of emerged leaves on the main shoot and the time when stem elongation began (‘ear at 1 cm’), plant characters used to assess the stage for various agronomic treatments, were measured in parallel with apex development. The relationships between number of emerged leaves and the length of the longest leaf sheath and stage of development were found to vary with sowing date. The stage ‘ear at 1 cm’ provided a good guide to shoot apex development. Stem length and number of elongated internodes varied with date of sowing. Some of the variation in number of emerged leaves at a given stage and in the final number of elongated internodes was found to be correlated with total number of leaves on the main shoot. The form of analysis used indicated that sowing date may have important effects, via its effect on the number of leaves on the main shoot, on the duration of ear growth in wheat and barley and on the duration of ear formation in barley.
The basis of variation in date of ear emergence under field conditions among the progeny of a cross between two winter wheat varieties
Authors: Hoogendoorn J.
Published: March 2009

From the progeny of a cross between the winter wheat varieties Norman and Talent early and lateF5lines were selected in the field. These selections and the two parental varieties were grown in controlled environment cabinets to assess their sensitivity to photoperiod and vernalization.

TheF5selections and Norman and Talent were also grown in field trials, at the Plant Breeding Institute in Trumpington, and at The Murrays Experimental Farm of the Scottish Crop Research Institute, near Edinburgh.

Norman was more sensitive to photoperiod and vernalization than Talent. The earlyF5lines were relatively insensitive to photoperiod and/or vernalization. The late lines were sensitive to both photoperiod and vernalization. Differences in date of ear emergence among the selections were found which were independent of photoperiod and vernalization sensitivity. This variation in ear emergence, described as earlinessper se, was similar under controlled environment conditions and in the field, and was also shown to be similar in magnitude to that due to differences in sensitivity to photoperiod and vernalization. Both sources of variation can be exploited to modify time of ear emergence under field conditions in Great Britain.
Response of sesame varieties to environment in the Sudan central rainlands
Authors: Osman H. E. , Nour A. M.
Published: March 2009

Twenty-seven sesame varieties from Sudan and U. S. A. were grown in replicated trials in the Sudan central rainlands from 1979 to 1982. Regression coefficients were calculated giving response to environmental indices based on location and year mean yields. Entries with high mean yields generally had regression coefficients exceeding unity and were equal to or better than entries having smaller response even in poor environments. Few lines were identified as desirable varieties which combined relatively high yield and stability of performance, thereby deserving a place in both commercial production and future breeding programmes.
The effect of increasing acidity on the solubility of calcium, magnesium and phosphorus in certain cereals and pure salts
Authors: Hill R. , Tyler C.
Published: March 2009

1. The solubilities of calcium, magnesium and phosphorus in bran, wheat, oats and certain mineral supplements have been determined at pH values between 6·5 and 1·0.

2. The solubility of calcium in calcium carbonate varied with the cereal present, but it was always completely soluble at pH 3·0 and below.

3. The calcium present in bran and wheat was not readily soluble; that in oats was fairly readily soluble.

4. Magnesium dissolved more readily at higher pH values than calcium.

5. Phosphorus in bran (with or without added calcium), and that present as pure salts, was almost completely dissolved at pH 3·0 and below, but very low phosphorus solubilities were found at these pH values in oats and, to a lesser extent, wheat.

6. These results have been considered in relation to the acidification of food which occurs in the true stomach.
Extracted herbage leaf protein for poultry feeding I. Introduction and feeding trial with laying hens
Authors: Hughes G. Pearson , Eyles Dudley E.
Published: March 2009

1. The extraction of leaf protein from autumn-grown perennial ryegrass is described.

2. The composition, chemical analysis and rate of feeding of two mashes compared in the experiment are given. The same basal cereal mixture was used in each ration, with fish meal added to one and leaf protein and minerals to the other.

3. Two groups of three birds were kept on each ration. Nine-month-old Brown Leghorn × Light Sussex pullets, in full lay, were used.

4. The birds were given a 6 weeks' preliminary period on a uniform ration to accustom them to the experimental conditions and to ascertain their potential egg production.

5. In a 10-week feeding trial no difference occurred in the number of eggs or the total weight of eggs laid by the birds fed on either ration.

6. A small loss of body weight occurred in the birds in both treatments.

7. Egg-quality determinations indicated that the specific gravity of the eggs was not affected by the differential feeding. Yolk height was greater in eggs from birds fed on the ration containing fish meal. This ration also resulted in a higher number of eggs with rough shells and containing a higher content of foreign bodies.

8. The eggs from both treatments had low ‘Yolk-colour indices’, showing that the leaf xanthophylls were not present in quantities in the leaf-protein extract.
The nutritive value ofCalluna vulgarisII. A preliminary study of digestibility
Authors: Armstrong D. G. , Thomas Brynmor
Published: March 2009

1. Earlier work on the digestibility ofCalluna vulgarishas been briefly reviewed.

2. Determination of the digestibility of heather has been made by two methods, viz. (a) the conventional procedure involving the use of metabolism crates and (b) the lignin-ratio technique applied to tethered sheep.

3. A diet consisting of heather alone, and fed in metabolism crates, proved unsatisfactory as a result of low feed intake. Agreement between duplicate sheep in respect of digestive capacity was also poor.

4. Satisfactory feed intakes were attained when heather was admixed at levels of 40 and 70% with hay. At both levels the digestibility of the organic matter was approximately the same, and agreement between sheep was good except for crude protein.

5. The lignin-ratio technique applied to tethered sheep gave digestibility coefficients for organic matter which were consistent with those obtained by the conventional method; the values for crude protein were somewhat higher. While the organic matter of 10-year-old heather was digested to about the same extent as that of 4-year-old heather, its crude protein digestibility was rather less.

6. The advantages and disadvantages of both methods have been discussed; it has been concluded that the lignin-ratio technique is likely to play a useful part in future work of this kind.

7. These preliminary results suggest that heather has a higher nutritive value than earlier work would indicate, and that even the winter foliage may compare favourably with hay of moderate to poor quality.
A correlation between egg albumen weight and shank width in inbred lines of brown leghorns
Authors: Blyth J. S. S.
Published: March 2009

In the inbred lines of a flock of Brown Leghorns, it was noted that the line means for albumen weight ranked in the same order as those for shank width. The parallelism was not due to the large differences in body weight existing between the lines.

It was established that variations in albumen weight were more closely associated with changes in shank width than were those of yolk weight. It is possible, but not definitely established, that shell weight follows the behaviour of albumen in this respect.
The effect of environmental temperature and humidity on the temperature of the skin of the scrotum in ayrshire calves
Authors: Beakley W. R. , Findlay J. D.
Published: March 2009

1. The temperature of the surface of the scrota of three 4-month-old Ayrshire calves has been measured in environments of 15, 20, 25, 30, 35 and 40° C. at a low humidity of 17 mg./l. absolute humidity and in environments of 30, 35 and 40° C. at a high humidity of 7 mg./l. saturation deficit. Five replicate experiments were performed at each environment on each animal and the animals were exposed to each environment for 6 hr.; measurements of scrotal temperature were made once every 5 min.

2. The scrotal surface temperature increased with increasing environmental temperature ranging from 32° C. at 15° C. to 39° C. at 40° C. The rates of increase in scrotal surface temperature with environmental temperature were curvilinear for two of the animals and rectilinear for the other. For the two whose rates of increase were curvilinear the rate of increase was constant at 0·2° C./° C. environmental temperature in the range 15–25° C.
The digestibility of linseed oil and mutton fat by chicks
Authors: Duckworth J. , Naftalin J. M. , Dalgarno A. C.
Published: March 2009

1. There was no evidence that the higher body temperature of the chick, compared with other animals, conferred any advantage on it in the digestion of high melting-point fats, as exemplified by mutton fat.

2. The digestibility of linseed oil ranged from 95·0 to 99·9%. The highest digestibility observed for mutton fat was 88·1%.

3. The capacity to digest considerable quantities of linseed oil was rapidly developed in the chick. Adaptation to digest mutton fat was much slower.
Electrical measurement of bull sperm activity. Comparison with visual assessment
Authors: Rothschild Lord
Published: March 2009

The visual method of assessing the quality of semen, in use at Artificial Insemination Centres, has been compared with assessments based on measurements of impedance change frequency (I.C.F.) on the same samples. Analysis of the results shows that I.C.F. measurements could probably be substituted for visual assessments at A.I. Centres, without conception rates being adversely affected.
Factors influencing the relationship between the secretion of milk and butterfat
Authors: Edwards Joseph
Published: March 2009

A review of published work emphasizes the existence of a fundamental relationship between the quantity of milk and butterfat per cent. This general relationship may be stated thus: as the quantity of milk increases, the quantity of fat increases also, but at a slower rate. Therefore, the fat per cent, or concentration, falls as the volume of milk increases.