bluuebunny/crossref_metadata_2025 huggingface dataset:
Some effects of bran and cellulose on the water relationships in the digesta and faeces of pigs Part I. The effects of including bran and two forms of cellulose in otherwise normal rations
Authors: Cooper P. H. , Tyler C.
Published: March 2009

1. Attempts to investigate the physical properties of bran, and other feedingstuffs, with regard to their ability to absorb and retain water, have been outlined.

2. Two experiments have been described in which pigs were fed bran, fibrous cellulose, or different levels of powdered cellulose, added to normal pig rations. These experiments involved 24 hr. faecal collections, and ultimate slaughter of the animals, together with analysis of faecal material and gut contents.

3. The addition of bran or fibrous cellulose to a ration causes a reduction in the average percentage of dry matter in the faeces, but tends to emphasize fluctuations in faecal dry-matter percentage, which are attributed to fluctuations in rate of passage through the large intestine.

4. The behaviour of the powdered cellulose was anomalous, giving rise to hard stools. It appeared to be almost inert in relation to water.
Studies on the Northern Rhodesia Hyparrhenia veld Part I. The grazing behaviour of indigenous cattle grazed at light and heavy stocking rates
Authors: Smith C. A.
Published: March 2009

1. The normal pattern of grazing behaviour of free-range indigenous cattle under conditions of lenient stocking and overstocking has been studied throughout the year.

2. There was a fairly fixed daily pattern of herd behaviour. The cattle usually started day grazing round sunrise and ceased approximately 1 hr. after sunset. There was a morning and afternoon peak of intense grazing activity separated by a rest period and watering about midday. There was usually one peak of night grazing.

3. The average daily grazing times varied from 8 hr. during the rains period of relative feed abundance, to about 13 hr. during the dry season period of malnutrition.

4. During the dry season there were no major differences in grazing times between the leniently stooked and overstocked groups. Both herds were losing weight.

5. The relatively greater weight gains of the overstocked herd compared with the leniently stooked group during the rains resulted from the increased grazing times of the overstocked herd.

6. The night grazing remained fairly constant at approximately 20% of the total daily grazing time.

7. There were no seasonal effects on the pattern of grazing behaviour. High daytime temperatures did not cause an increase in the proportion of night grazing of indigenous cattle.
The effects of annual precipitation and its distribution on grain yield of dryland cereals
Authors: Hadjichristodoulou A
Published: March 2009

Data collected from 1968 to 1981 were used to study the effects of annual precipitation and its distribution on grain yield of three barley and six wheat varieties from 19–47 environments.

The percentage of the variation in grain yield explained by annual precipitation varied with variety and species (5–31% in barley and 31–79% in wheat). The distribution of precipitation was the major factor affecting grain yield, although it varied with variety, and explained 72–92% of the variation in barley and from 75 to 98% in wheat.

Only 33 of the 144 simple correlation coefficients between grain yield and precipitation during each of the 16 fortnightly periods were significant. The expected average effect on yield due to additional precipitation above the mean showed positive effects in barley during the presowing and heading to flowering periods; no consistent trend was found in the wheat.

Improved agronomic practices could alleviate the adverse effects of the low and unevenly distributed precipitation by reducing losses and increasing storage of water in the soil. Breeding could contribute greatly towards high and stable yields in drylands.
The effect of implantation of anabolic steroids into suckling and ruminating lambs on the metabolism of alanine in livers perfused in the presence or absence of volatile fatty acids
Authors: Richardson T. C. , Jeacock Marjorie K. , Shepherd D. A. L.
Published: March 2009

The effect of implantation of trenbolone acetate and oestradiol into lambs soon after birth on the metabolism of alanine in the presence and absence of propionate has been studied in isolated perfused livers obtained from suckling and from ruminating lambs. The effect of butyrate on the metabolism of alanine in the presence and absence of propionate has been studied in livers obtained from the steroid implanted lambs.

Glucose production in the presence of alanine by livers from non-implanted suckling lambs was more than 3 times greater than that by livers from non-implanted ruminating lambs. Steroid implantation did not affect alanine uptake by the livers but metabolism within the livers was altered. Significant interactions were observed between the age of the lambs and whether or not they had been implanted with steroids for the rates of net glucose production in the absence of propionate (P< 0·01) and for the rates of release of urea by the livers in the presence of (P< 0·05) and absence of propionate (P< 0–01).

Propionate did not affect alanine uptake by livers obtained from either suckling or ruminating lambs, but there was a significant interaction (P< 0·05) between the age of the lambs and whether or not butyrate was infused, indicating that butyrate depressed alanine uptake by livers obtained from implanted ruminating lambs perfused in the absence of propionate. Despite this depression of alanine uptake the rates of net glucose production and urea production were unchanged, indicating that butyrate modified the metabolism of alanine in the livers of implanted ruminating lambs in that a greater proportion of the alanine carbon taken up must have been converted to glucose. Butyrate stimulated net glucose production in the presence of propionate and alanine in livers from suckling (P< 0·05) but not ruminating lambs. Butyrate was ketogenic and the release of 3-hydroxybutyrate accounted for 45 and 30% of the carbon taken up as butyrate by livers from suckling and ruminating lambs respectively perfused in the absence of propionate. Propionate was antiketogenic. Propionate inhibited urea formation from alanine by livers from implanted suckling (P< 0·05) and implanted ruminating (P< 0·001) lambs. This effect was diminished by the presence of butyrate. Lactate was released in the presence of propionate and accounted for approximately 12–5% of the carbon taken up as propionate.

It may be concluded that implantation of lambs with anabolic steroids maintains hepatic gluconeogenesis from alanine at rates more closely resembling those found in younger suckling lambs. The effects of the volatile fatty acids on alanine metabolism are likely to be of physiological significance when sheep are fed diets which result in a markedly altered pattern of rumen fermentation.
Leaf appearance and extension in field-grown winter wheat plants: the importance of soil temperature during vegetative growth
Authors: Hay R. K. M. , Wilson G. Tunnicliffe
Published: March 2009

Mainstem leaf appearance and leaf extension were monitored at 7-day intervals throughout the vegetative development of field-grown winter wheat plants, during two growing seasons 1977–9. Using hourly air and soil temperature records, it was found that the rate of leaf appearance was controlled by soil temperature, with the best linear relationships being obtained using accumulated soil temperature above a base temperature of 0 °C at 1 and 5 cm depth. Leaf appearance could be predicted equally well using 09.00 G.M.T. screen air temperatures although deviations from each linear relationship were found during very cold periods when slow leaf extension rates delayed leaf appearance.

Leaf extension was also found to be linearly related to temperature, with the best fit being obtained using accumulated soil temperature above 2·5 °C at 5 cm depth, suggesting a threshold of 2·5 °C for leaf extension. The response to temperature (extension per unit of accumulated temperature) was the same for all the leaves of a given plant, or sowing date; however, the fact that the rate of leaf extension increased progressively with sowing date suggests that plant response to temperature may be determined at crop emergence (possibly mediated by rate of change of day length). Leaf extension rates could be predicted satisfactorily using 09.00 G.M.T. soil temperatures (5 or 10 cm) but less so using screen air temperatures.

The prediction of plant leaf areas or crop leaf area indices using such relationships between temperature and leaf growth was found to be hampered by rapid and irregular rates of leaf senescence.
Leaf and curd production in cauliflower varieties cold-treated before transplanting
Authors: Wurr D. C. E. , Fellows Jane R. , Crisp P.
Published: March 2009

Two experiments at Wellesbourne studied the effects of cold treatments on the leaf and curd production characteristics of a range of annual and biennial varieties of cauliflowers.

Cold treatments delayed curd initiation and had a variable effect on the final number of leaves, but reduced the spread of curd initiation of plants which were 5 weeks old when cold-treated. The overall rate of leaf production and the final number of leaves generally increased with later-maturing varieties while initial rates of curd expansion generally declined.

The annual varieties produced a small number of leaves and fairly synchronously formed a curd which developed rapidly; the biennial varieties had a higher rate of leaf production after transplanting and then changed to the generative state over a more prolonged period, following which the curd developed slowly.
The effects of very deep ploughing and of subsoiling on crop yields
Authors: Russell E. W.
Published: March 2009

1. Deep tillage, namely, ploughing to a depth exceeding 12 in., or subsoiling to a depth of about 18 in., increased crop yields on about half the fields in which an experiment was made. Unfortunately, it was not possible to recognize what was the difference in soil properties between the 50% of fields that responded appreciably to deep tillage and the remainder whose yields were either unaffected or sometimes reduced by deep tillage, though, as one would expect, sands were normally less responsive to deep tillage than the heavier soils.

2. On the clay soils, deep ploughing in autumn tended to give a surface soil that dried out up to several weeks earlier in the spring than land that was shallow ploughed. Subsoiling did not cause the surface soil to dry out in the same way. Only rarely did the subsoil brought up by deep ploughing give difficulty in working down to a seedbed, and probably in as high a proportion of fields the subsoil worked easier than the surface soil.

3. On the clays and loams, the response of potatoes to deep tillage was more marked on fields that were heavily manured than on those lightly manured.

4. Sugar beet normally gave a higher yield if its potash and phosphate was spread on the land before ploughing, even if this was in the autumn, than if it was applied in the seedbed. The exceptions to this result were for soils heavier than sandy loams if ploughing depths exceeding 12 in. were used, for the yield of beet was, on the average, depressed on these soils if the potash and phosphate was ploughed in compared with it being worked into the seedbed.

5. Deep ploughing tended to give better control of many perennial weeds, and often of annual weeds than shallow ploughing. It is suggested that much of this benefit could be obtained when ploughing to 9–10 in. deep if ploughs were used that cut a furrow considerably wider than the conventional 10½–11 in. furrow, so allowing more complete inversion of the furrow slice.
The effect of nitrogenous fertilizers on the non-protein nitrogenous fraction of grassland herbage
Authors: Ferguson W. S. , Terry R. A.
Published: March 2009

The non-protein nitrogenous (NPN) fraction of grassland herbage given a range of repeated nitrogenous fertilizer treatments has been examined. The herbage was intended for conservation and the treatments were 0, 2, 4, and 6 cwt. ‘Nitro-Chalk’ per acre per cut, applied early, after cutting, and late, 10–14 days before cutting.
Lucerne investigation: II. Pollination and seed setting in lucerne strains
Authors: Zaleski A.
Published: March 2009

1. The differences between strains in respect of tripping, pollination, self- and cross-fertilization, the number of pods and seeds set under comparable conditions, and the influence of weather and insects on these aspects was investigated during 1953–5 at Cambridge. Early, mid-season and late strains of lucerne were included in the experiments.

2. Early strains under natural conditions had a significantly higher percentage of florets tripped, and pods formed, than mid-season or late strains. The ease with which early strains tripped, and the likelihood that biological characters of their flowers were better adapted to environmental conditions, are possible reasons for their high percentage of pods set.

3. Tripping is essential for seed setting; at least 98·5% of pods resulted from florets tripped by insects or automatically.

4. There was little difference between strains in the percentage of self-fertilized florets, although in the early strains there was a slightly higher percentage, as well as a higher number of selffertilized plants. There was little difference between strains in the average number of seeds set per pod which was about 1·9 for artificial tripping and selfing and 1·5 for selfing under continuous cover. Under natural conditions, the estimated proportion of pods formed due to selfing was 20% in Eynsford and Du Puits, 12% in Provence and 16% in Grimm. The difference between strains in the percentage of pods formed by artificial crossing was small. The average number of seeds set per pod was 3·9 under natural conditions and 6·7 under artificial crossing for all strains.

5. Sunshine and high temperature encouraged tripping while rainfall suppressed tripping and pod setting. When the effect of temperature and rainfall were eliminated, duration of sunshine was the most important factor influencing tripping. Some variations in tripping and pod setting were found among plants of all strains in different seasons.

6. The population of wild bees was very low. Honeybees and other small insects caused some accidental tripping and crossing, especially in early strains.
A comparison of three ultrasonic machines (Danscan, AIDD (NZ) and Body Composition Meter) and subjective fat and conformation scores for predicting chemical composition of live sheep
Authors: Bass J. J. , Woods E. G. , Paulsen W. D.
Published: March 2009

Ultrasonically measured backfat depths and subjective fat and conformation scores taken on 123 Romney ewes were related to the chemical composition of the carcass in trial 1. Fat depths at one position over the eye muscle, determined using ultrasonic machines with a single probe, were similar to the best judge's fat scores at predicting carcass composition after adjustment for pre-slaughter live weight. Fat depths measured from a two-dimensional scan (Danscan) did not predict carcass composition as well as most of the judges' fat scores. Judges' conformation scores failed to improve the prediction of composition after adjustment for live weight and fat score.

In trial 2, two ultrasonic machines of the single probe type provided accurate measure of carcass fat depths on both full fleeced and shorn sheep. Ultrasonically measured fat depths would appear to be a useful method for selecting lean breeding stock and for training inexperienced stock judgesto assess fatness of sheep.
Fasting and maintenance metabolism of sheep
Authors: Blaxter K. L. , Boyne A. W.
Published: March 2009

A series of measurements of the heat production of 16 adult sheep made at intervals of not less than 4 weeks when they were given precise amounts of different diets at about the maintenance level of nutrition were analysed statistically. The total number of observations was 365. For some sheep the observations spanned periods of more than 3 years and none spanned less than 1½ years.

There were no time-related trends in the metabolizability of the gross energy of the diet. It was found that the measured heat productions, the heat productions corrected to zero energy retention and the heat productions corrected to zero feed intake (calculated fasting metabolism) were sinusoidal with time. The amplitude of the sine coefficient was about 14% of the mean value, and in some sheep there was in addition a linear secular trend. The phase of the sine function was such that minimal metabolism occurred in midwinter and maximal metabolism in midsummer.

The results suggest that the seasonal variation in voluntary feed intake is associated with a similar seasonal variation in basal metabolic rate. The fact that all animals were given maintenance rations throughout further suggests that the higher metabolism is not due to higher feed intake.
A mass-selection method for the acclimatization and improvement of edible diploid potatoes in the United Kingdom
Authors: Carroll C. P.
Published: March 2009

A mass-selection scheme for outbreeding diploid potatoes of the Phureja-Stenotomum Group is described; the scheme includes both seedling and ongoing tuber populations. Provision is made for higher yielding clones to contribute more true seed to ensuing generations. A computer is used to document and randomize the plantings. Selection criteria and methods are described. Results are given from an experiment to monitor progress. The use of diploid potatoes in British breeding, and the historical development of breeding methods, are reviewed in relation to the present mass-selection scheme.
The effect of nitrogenous fertilizer on the seed yield, and yield components ofPhaseolus vulgaris
Authors: Scarisbrick D. H. , Olufajo O. O. , Daniels R. W.
Published: March 2009

Phaseolus vulgarisis grown in the U.K. primarily for its edible immature pods (dwarf French beans). The possibility of also using this species as a combinable break crop in south-east England was investigated during 1972–80 when trials were undertaken on the nitrogen fertilizer requirement for commercial seed production.
The potential of sunflower as a crop for ensilage and zero-grazing in northern Britain
Authors: Harper F. , Donaldson Elizabeth , Henderson Annie R. , Edwards R. A.
Published: March 2009

The growth, development, chemical composition and nutritive value of sunflower (cv. Fransol), was examined from the flower-bud (12 July) to milky-ripe seed (late September) stages. Dry-matter yield increased from 2·1 to 14·1 t/ha over the period. Drymatter content was low (100–110 g/kg) up to flowering, early in August, and then increased to 193 g/kg. Crude protein content declined after flowering and ether extract values were low throughout the period. Organic-matter digestibility in vitro and derived metabolizable energy values declined rapidly with the onset of flowering. Gross energy values, calculated from the proximate constituents, increased to 17·6 MJ/kg D.M. at the end of the period. Calcium to phosphorus ratios varied from 5·6 to 7·4:1.

Sunflower was cut and fed to eight Friesian heifers over 3 weeks from the onset of flowering. Average daily D.M. intake was 63·5 g/kg W0·76 and the organic-matter digestibility was 0·684. Average live-weight gain was 0·79 kg/day.

Fresh sunflower was successfully ensiled without an additive 2 weeks after flowering and the silage (pH 4·0) was fed to three cross-bred wethers in a feeding trial. The organic-matter digestibility was 0·649, the metabolizable energy 8·0 MJ/kg D.M. and the average D.M. intake 6·73 g/kg W0·75. In a metabolism trial, with four fistulated sheep, the organic-matter digestibility was 0·718, the metabolizable energy 9·4 MJ/kg D.M. and the D.M. intake 43·1 g/kg W0·75. Rumen pH decreased and total volatile fatty acid concentration increased markedly within 2 h of feeding the silage. Molar proportions of acetic and propionic acid (0·539 and 0·381), 1 h after feeding, were typical of cereal-based diets. Ammonia-nitrogen concentration increased to a maximum of 216 mg/1 within 2 h of feeding.

The good yield and animal performance from fresh sunflower make it a possible annual crop for zero-grazing in late summer in northern Britain. Satisfactory results from feeding sunflower silage suggest that the crop has potential for ensilage if the problem of effluent can be overcome.
Effect of temperature on cold dehardening of Lolium perenne L. seedlings
Authors: Fuller M. P. , Eagles C. F.
Published: March 2009

Cold dehardening responses of seedlings of three cultivars of Lolium perenne L. (Premo, S.23 and Grasslands Ruanui) were studied in different temperature regimes following hardening at 2 °C. Seedlings of the three cultivars dehardened rapidly at 15 °C after partial hardening for 4 days, whereas there was a lag before dehardening occurred in seedlings of Premo and S.23 which were hardened for 28 days. At 10 °C dehardening did not occur in Premo and S.23 and occurred only slowly in Grasslands Ruanui. Alternating temperature regimes of 15 °C(day): 2 °C (night) gave increased levels of hardiness when the daily period of exposure to 15 °C was 8 h but only maintained the level of hardiness when it was extended to 16 h.

A tentative scheme of threshold temperatures for hardening and dehardening is proposed.
Studies on reproduction in prolific ewes:7. Variability in the growth of individual foetuses in relation to intra-uterine factors
Authors: McDonald I. , Robinson J. J. , Fraser C.
Published: March 2009

The weights of 44 twin foetuses, 99 triplets and 44 quadruplets, varying in gestational age from 55 to 145 days, were studied in relation to age, sex, litter size, uterine position, placental structure and weight, and ovulation rate. Triplet and quadruplet foetuses were more variable in weight, within litters, than were twins. The difference increased with foetal age and was attributed to increased competition between foetuses which were located within the same horn of the uterus. The effect was largely associated with differences in placental development, i.e. numbers of cotyledons and weight, but those differences did not entirely account for the reduction in foetal weight with increasing litter size. Differences in placental development, arising from embryo mortality, also accounted for the reduction in foetal weight when ovulation rate exceeded litter size. In contrast, differences in foetal weight associated with the sex of the foetuses were only partly mediated by differences in cotyledon weight. Foetuses in the larger litters are thus not only lighter in weight but are more variable in weight, the increased variability being controlled by events in early pregnancy.
The estimation of metabolizable energy in maize and in wheat by-products using chickens, with observations on problems of prediction from chemical composition
Authors: Davidson J. , Graham S.
Published: March 2009

In a study with chicks, the metabolizable energy (ME) values of two maize and two wheat offal samples were estimated using regression procedures in which the ME of the fishmeal supplement, common to all diets, was first calculated.

From chemical analysis, the wheat offal samples would have been expected to yield at least as much ME as oats, but results fell short of expectation by as much as a quarter in the case of one sample of wheat middlings. The significance of these findings is discussed.

By comparison with previously determined ME values on the same samples fed to sheep, the chicken tended to metabolize more of the maize energy and less of the wheat offal energy.
The potential of calcium thioglycollate and fibre protectants for use in chemical shearing
Authors: McDonald B. J. , Bunch R. J. , Hopkins P. S.
Published: March 2009

The wool-severing properties of 2·8% aqueous solution of calcium thioglycollate were increased by 76% by dissolving the depilatory agent in a KCl-NaOH buffer of pH 12·5. The optimum Ca-thioglycollate concentration for defleecing was 3·6%. One ml of this solution defleeced an area of 12·1 cma.

A comparison of five buffers and water as solvents for 3·6% Ca-thioglycollate indicated that the area of skin defleeced was directly related to solution pH and the stubble remaining appeared to be inversely related to solution pH. A KCl-NaOH buffer of pH 12·0 provided the optimum relationship between area defleeced (10·2 cm2/ml applied) and stubble (ca. 2 mm wool) remaining.

Single site applications of 0·1–1·0 ml of defleecing agent at skin level were compared and it was shown that the application of 0·1 ml aliquots would require 320 ml solution to defleece an average-sized sheep.

Preliminary evaluation of 6% formaldehyde buffered to pH 6 and a carbowax-citric acid solution of pH 2 showed that protection of fibres against dissolution by Cathioglycollate solutions can be sustained for 21 days. Pre-treatment with these compounds could therefore produce a protected band of wool immediately above the proposed site of wool dissolution.

The practical implications of these findings are discussed with regard to a wool harvesting programme.
Calcium and phosphorus retention by the milk-fed lamb, with estimates of the endogenous losses
Authors: Walker D. M.
Published: March 2009

The total body content of calcium and phosphorus of twenty-seven male cross-bred lambs was determined, after the lambs had suckled ewes at pasture for between 2 and 5d. The relationships between empty body weight and Ca and P content were described by linear regression equations. The comparative slaughter method was used with thirty-seven lambs, and the balance method with twenty lambs, to determine the retention of Ca and P from cow's milk by lambs given intakes of milk ranging from maintenance (or below) toad lib. The availability of Ca, calculated as true digestibility, was 88–1 %, and for P, 98–2 %. Estimates of net availability, calculated from the slopes of the regressions relating mineral intake to mineral apparently absorbed, were somewhat higher and close to 100%. The net efficiencies of Ca and P retention, as estimated from the slopes of the regressions relating mineral intake to mineral retention, were also close to 100%. The balance method gave higher estimates of Ca and P retention than the comparative slaughter method. Multiple regression equations were used to describe the dependence of P retention on N and Ca retention. A low-calcium diet was given to two lambs for 20 d and the endogenous losses of Ca (and P) in the faeces and urine were determined. The total endogenous losses were 9–5 + 0–9 mg Ca (and 30–3 ± 1–4 mg P) per kg live weight d, of which the urinary losses were 0–5 mg Ca (and 27–9 mg P). Requirements for Ca, calculated for the milk-fed lamb at live weights of 5 and 10 kg, were somewhat lower than those recommended by the Agricultural Research Council (1965), but P requirements were in close agreement.
The effect of plant population and fertility level on yield and its components in two determinate cultivars ofPhaseolus vulgaris(L.)Savi
Authors: Leakey C. L. A.
Published: March 2009

The biological and useful yield ofPhaseolus vulgariscv. ‘Banja’ and cv. ‘Diacol Nima’ were compared when sown at populations, in row spacings, equivalent to 5–4–32–3 plants m~2, at four levels of fertility achieved by the use of zero, five, ten and 20 cwt ae-1 respectively of a fertilizer mixture containing by weight 2:2:1 calcium ammonium nitrate, single superphosphate and muriate of potash. Yield and its components were determined at final harvest. The two cultivars behaved generally similarly. Crop Index, while highest in the plants with no fertilizer, was more or less constant for each cultivar over a wide range of biological yields in those plants receiving fertilizer. Yield is determined to the extent of 85–7% and 86–1% respectively for 'Diacol Nima’ and ‘Banja’ by the product of pods/plant and plants surviving to harvest. High densities, although giving the highest grain yields, are wasteful of seed in that the percentage of plants surviving to contribute to yield is much reduced.
Spacing and harvest date experiments with Maris Peer potatoes
Authors: Gray D.
Published: March 2009

In two experiments with potatoes the effects of plant population (from 13 to 59 stems/m2 in 1969 and 18–111 stems/m2 in 1970) and harvest date (from mid-June till late August/early September) on the yields of tubers and particularly those of canningsize (2–4 cm) were studied in the cv. Maris Peer.

Yields of canning-sized tubers increased linearly with increases in the number of mainstems over the range 13–64 stems/m2. The response was similar for harvests made at different stages of growth except for the period of 2–3 weeks after tuber initiation when the effect of plant population on yields was small. For crops grown at low plant populations yields of canning-sized tubers rose to a maximum early in the season and then declined with further growth of the crop. Progressive increases in plant population resulted in maximum yields at progressively later stages in the growth of the crop. The period over which it would have been possible to harvest crops having an acceptable quality and each giving their maximum yield was 4–6 weeks in 1969 and 3–4 weeks in 1970.

There was no effect of seed tuber size per se on total tuber yields or yields of tubers in size grades. In both years at least twice the weight of large (over 66 g) as opposed to small seed (22 and 27 g) was required to establish the same stem population/m2. The production and use of small seed suitable for canning potato production is discussed.
Heat-induced growth retardation and attempts at its prevention in barley and wheat coleoptiles
Authors: Onwueme I. C. , Laude H. M.
Published: March 2009

Intact barley coleoptiles subjected to high temperature stress of 46°C for up to 4 h showed a significant decrease in their growth rate, and in the final length attained by the coleoptiles before exsertion of the true leaves within. These effects of high temperature were progressively more pronounced with increase in duration of stress. Excised wheat coleoptile sections also experienced a similar growth retardation due to heat stress. This heat-induced growth retardation could not be prevented by exogenous applications of 0·5–100 ppm indole-3-acetic acid or 0·5–5 ppm gibberellic acid; nor by dilute aqueous solutions of calcium chloride, cobalt nitrate or zinc sulphate. The agronomic significance of heat-induced coleoptile stunting is briefly discussed.
Utilization of grass-silage nitrogen by growing sheep
Authors: Grenet Elisabeth
Published: March 2009

The digestibility, the voluntary intake and the nitrogen balance of 108 diets corresponding to 94 silages prepared from 20 fresh crops were measured in growing sheep. Series of silages were made from the same fresh forage. Each series included two controls: a direct-cut silage without additive and a direct-cut silage with formic acid, with a variable number of experimental silages with different additives.

Rumen ammonia concentration, measured on rumen-fistulated sheep, decreased when an additive was used. It increased with nitrogen intake and was inversely related to the organic-matter digestibility and the crude-fibre digestibility. It varied with the silage composition.

The crude-protein digestibility of direct-cut silages without additives was similar to or slightly higher than the crude-protein digestibility of the fresh crops. The addition of formic acid depressed the digestibility, but the addition of formaldehyde decreased it even more. The urinary nitrogen loss was higher for silages without additive than for the fresh crops and was decreased by the addition of formic acid. The addition of formaldehyde to formic acid had an additive effect.

Retained nitrogen was lower in silages without additives (12% of nitrogen intake) than in parent crops (15·7%). It increased when formic acid (15·8%) was added. The addition of formaldehyde at a low rate (1·5 l/t green fodder) to the formic acid did not increase the nitrogen retention whether expressed in g/day or as percentage of nitrogen intake, but the addition of formaldehyde at a high rate (3·5 l/t green fodder) to formic acid decreased nitrogen retention. The other additives based on cereals or whey did not improve the nitrogen balance compared with formic acid. Nitrogen retention differed according to plant species.

Retained nitrogen increased with digestible organic-matter intake and nitrogen intake. It increased with the silage water-soluble carbohydrate content. The higher the silage fermentation product content (ammonia, lactic acid, propionic acid), the lower the retained nitrogen. It appears that the nitrogen value of silages can be high provided that the silages are well preserved and that excessive protein breakdown is avoided.
The influence of size of animal and stocking rate on the herbage intake and grazing behaviour of cattle
Authors: Zoby J. L. F. , Holmes W.
Published: March 2009

Twenty-four Friesian cattle classed as large, medium or small and from 776 to 163 kg initial live weight (LW) were grazed over two successive 8-week periods. Two stocking rates were imposed and there were four replicates. Trios of animals, including one of each size, grazed in each paddock. Cattle changed stocking rate in mid-season. Herbage intake, live-weight gain and grazing behaviour were recorded.

The stocking rates resulted in large differences in herbage allowance and consequent differences in intake, live-weight gain and grazing behaviour. The large cattle were least able to compensate for the higher stocking rate by increasing grazing time or frequency of biting. Average herbage organic-matter (OM) intakes ranged from 13 g OM/kg LW for large animals to 28 g OM/kg LW for the small animals.
The effect of plant population density on carbohydrate partitioning and nitrogen fixation of two bean (Phaseolus vulgarisL.) cultivars in two tropical locations
Authors: Waters L. , Graham P. H. , Breen P. J. , Mack H. J. , Rosas J. C.
Published: March 2009

Bean cultivars Cargamanto (CIAT P590, indeterminate climbing, Type IV) and Puebla 152 (CIAT P498, indeterminate large vine, Type III) were grown at 20 and 60plants/m2at two locations in Colombia; a cool, high rainfall, mountainous area (Popayan) and a hot, medium rainfall, valley (Palmira). The crop growth period was compressed and P590 failed to flower at Palmira.where plant shoot weights tended to be higher and root weights lower than at Popayan.

Midday soil temperatures at 10 cm averaged 7·8 °C lower and N2(C2H2) fixation rate and nodule fresh weight over ten-fold higher at Popayan than at Palmira. Increasing the plant population density increased yield but reduced seed weight per plant and the fresh weight of all other plant parts, with shoots more severely affected than roots. Density had little effect on carbohydrate concentration or N2(C2H2) fixation per plant. The cultivars accumulated carbohydrates in different amounts but had similar rates of N2(C2H2) fixation. Concentrations of ethanol insoluble carbohydrates were several times higher in all plant parts at Popayan. Soluble carbohydrates showed similar, but smaller, differences.
Experiments with solid and liquid N-fertilizers and fungicides on winter wheat at Saxmundham, Suffolk, 1976–9
Authors: Penny A. , Widdowson F. V. , Jenkyn J. F.
Published: March 2009

In 1976 and 1977 late sprays of a urea-ammonium nitrate solution supplying 50 kg N/ha, and broad spectrum fungicides, were tested in factorial combination with 0, 50, 100 or 150 kg N/ha (as ‘Nitro-Chalk’) given either in April or in May to winter wheat. In 1976 leaf diseases were not assessed. In 1977 brown rust (Puccinia hordei) was prevalent and more severe than either mildew (Erysiphe graminis) or septoria (Septoria spp.). Its severity was decreased by the fungicides and by the late sprays of N. Yield and N content of the grain were increased by each increment of ‘Nitro-Chalk’; though % N in grain was larger, yield and N uptake were smaller when the ‘Nitro-Chalk’ was applied in May. The liquid N-fertilizer increased yield little after giving N in April and decreased yield after giving N in May; nevertheless it always increased N content of the grain. The fungicides increased yield only on plots given N in April; their effects on % N in grain were inconsistent.

In 1978 and 1979 isobutylidene di-urea (IBDU) supplying 63 kg N/ha in autumn, ‘Nitro-Chalk’ supplying 0, 50, 100 or 150 kg N/ha in April, late sprays of urea solution supplying 50 kg N/ha, sprays of broad spectrum fungicides and sprays of the rust fungicide benodanil were tested in factorial combination (4 × 24) in a ½ replicate design.

In both years septoria was more severe than either brown rust or mildew. The broad spectrum fungicides decreased septoria in 1978, but not in 1979. In 1978 (after wheat) 150 kg N/ha as ‘Nitro-Chalk’ was needed for maximum yield, but in 1979 (after beans) only 100 kg; N content of the grain was increased by each increment of N each year. IBDU in the seed bed was less effective than equivalent ‘Nitro-Chalk’. The urea sprays increased yield and most where the least N was given in spring; they always increased grain N content. In 1978 the broad spectrum fungicides increased yield only with 150 kg N/ha in spring, but in 1979 with each amount of N; they affected % N in the grain inconsistently. The rust fungicide little affected yield, but decreased % N in the grain.

The weight of 1000 grains was irregularly affected by ‘Nitro-Chalk’ during 1976–1979. However, in all 4 years, 1000-grain weights were increased both by the liquid N fertilizer and by the broad spectrum fungicides and were largest where both had been sprayed.
Some causes of yield variation in an intensive spring barley experiment at Woburn, 1972–8
Authors: Hornby D. , Henden D. R. , Catt J. A.
Published: March 2009

An experiment with two blocks containing phased sequences of continuous spring barley after beans or fallow was located on sandy soil over Lower Greensand on a gentle north to south (N–S) slope at Woburn Farm. Season had the greatest effect on yield with a 135% difference between the worst (1975, 1·73 t/ha) and the best (1974, 4·06 t/ha). years. N–S position was the next most important factor with average differences of 65 and 52% between the plots at the top and bottom of the site in blocks I and II respectively. The third most important factor was E–W position which gave a maximum difference of 35% in 1975.

A fertility trend with a strong linear component, which was most conspicuous in drier years, followed the main slope of the experiment and was attributed to erosion (fieldwash). After 1972 as different cropping sequences were progressively introduced, yield variation due to crop sequence differences was confounded with this positional effect.

Crops in the eastern block were taller by l·5–12·3% and, after adjustment for the linear trend, yield was on average 15·6% greater than in the western block. The site is astride a N–S soil boundary with Stackyard series to the east and Cottenham series to the west. The Stackyard soil has a greater available water capacity, and is subject to drought less frequently than the Cottenham soil. Using Penman's (1971) data for the Cottenham series at Woburn and estimates of profile available water for the two series elsewhere on the farm, theoretical yields were derived, which were generally greater than actual yields adjusted for the N–S linear trend (block means 1·47–4·32 t/ha), but which showed similar trends in the between-block differences. Explanations for discrepancies between theoretical and actual yields are discussed. The incidence and severity of take-all disease and differences in soil pH were always small and unlikely to have caused significant yield variations.
Variability of wheat yields in England and Wales
Authors: Church B. M. , Austin R. B.
Published: March 2009

Information is assembled on how much wheat yields vary from place to place, from year to year and between years in England and Wales. Some indication of the practical importance of this variation is given by comparisons with the yield differences caused by individual management decisions as measured in comparative experiments, and with plot-to-plot variation in such experiments.
The effect of plane of nutrition on the growth and development of the East African dwarf goat. Part II. Age changes in the carcass composition of female kids
Authors: Wilson P. N.
Published: March 2009

1. The age changes in carcass composition of female kids killed at birth, 9, 16, 25 and 30 lb. are described.

2. The organs and tissues of the kids were weighed both wet and oven-dried, allowing the dry-matter percentages at different stages of growth to be calculated. The total dry-matter percentage for day-old kids averaged 26·5%, rising to a maximum of 40·5% at the 25 lb. stage. The greatest increase in dry-matter percentage was between birth and the 9 lb. stage, which was reached at approximately 1 month. This increase in dry matter is chiefly due to a steady rise in the dry-matter content of the muscular and skeletal tissues; from 20·2 to 25·4%, and from 34·3 to 59·6%, respectively, between birth and maturity.

3. The various joints of the kid were weighed and recorded separately, and the changes in the proportions of the joints illustrated centripetal growth. At birth, the joints were present in the following proportions: thorax 30%; legs 40%; head 20%; pelvis 10%. As the kid developed, there was a marked increase in the proportion of thorax and pelvis, accompanied by a corresponding decrease in the proportion of the head and foreleg.
Denitrification in soil. I. Methods of investigation
Authors: Bremner J. M. , Shaw K.
Published: March 2009

1. Methods of investigating denitrification in soil are critically discussed with special reference to methods based on total-N analysis.

2. A modified Kjeldahl method of determining nitrogen which includes nitrate and nitrite and is applicable to waterlogged soil is described and the use of this method in studies on denitrification in soil is illustrated and discussed.

3. It is shown that rapid denitrification of nitrate in soil can be induced by incubating the soil under waterlogged conditions with organic materials such as glucose and that denitrification can be followed by total-N analyses if the organic material used to induce denitrification is not added in such excess that it also promotes significant fixation of atmospheric nitrogen.

4. The percentage of added nitrate-N lost by denitrification on incubation of waterlogged soils with different amounts of nitrate and sufficient glucose for denitrification was found to be the same whatever the level of application of nitrate.

5. Denitrification of nitrate in waterlogged soil containing glucose was found to be accompanied by a rapid but temporary accumulation of large quantities of nitrite and by the formation of smaller amounts of ammonia. Hydroxylamine could not be detected during denitrification, but it was found that this compound was rapidly decomposed in the soils examined by a process which appeared to be purely chemical.

6. It is shown that denitrification of nitrate in soil is a microbiological process and that the viability of the micro-organisms responsible for denitrification is not affected by air-drying and storage of the soil.
Comparisons between placing and broadcasting of nitrogen, phosphorus and potassium fertilizers for potatoes, peas, beans, kale and maize
Authors: Widdowson F. V. , Cooke G. W.
Published: March 2009

1. In eight experiments on main-crop potatoes in 1953–4 placing 0·5 cwt. N/acre in a band beside the seed tended to give higher yields than broadcasting the dressing; when 1·0 cwt. N/acre was applied, broadcasting tended to be superior to placement. There were no consistent gains from placing 1·5 cwt. K2O/acre.

2. Four other potato experiments in 1954–6 tested all combinations of placing and broadcasting two levels of nitrogen and potassium. There was no clear relationship between the effects of broadcasting or placing one nutrient and the way in which the other nutrient was applied. When 0·5 cwt. N was applied, placing gave higher yields in seven out of ten possible comparisons (one effect was significant). With 1·0 cwt. N/acre there were also seven of ten comparisons in favour of placement (three significant effects), but in two other comparisons broadcasting gave significantly higher yields. Placing potassium gave higher yields than broadcasting in sixteen out of twenty comparisons (six significant effects), in one of the remaining comparisons broadcasting potassium was significantly superior. Placing of the potassium and, to a lesser extent, the nitrogen components of a complete potato fertilizer is likely to be beneficial.

3. In two experiments each on green peas and broad beans placing of phosphorus and potassium separately and together gave consistently higher yields than broadcasting these nutrients. When nitrogen was used in addition to phosphorus and potassium there were small gains in yield of broad beans provided the mixture was placed. There were no gains in yields of green peas from nitrogen however the mixture was applied.
Foetal dwarfism in sheep—an effect of high atmospheric temperature during gestation
Authors: Yeates N. T. M.
Published: March 2009

The course of pregnancy was followed in three groups of Peppin-strain Merino ewes. Group 1 of seven ewes, maintained on a high plane of nutrition, all lambed; the mean birth weight of lambs was 8 lb. 6 oz. The six ewes in group 2, kept on a low plane of nutrition, all lambed; the mean birth weight of their lambs was 1 lb. 9 oz. lower (P<0·01). The seven ewes in group 3 kept on a low plane of nutrition and subjected daily to temperatures of 112° F. dry bulb, 92° F. wet bulb, produced only four lambs; the mean birth weight was 4 lb. 6 oz. less than those from group 1, and 2 lb. 13 oz. less than those from group 2 (P < 0·001).

Scale photographs of the lambs, and X-rays and measurements of their long bones, after dissection, showed that the lambs of group 3 were miniatures: their skeletons were much reduced in size, whereas low nutrition alone (group 2), caused little skeletal reduction.

The mechanism of dwarfing is not clear. However, fore-cannon bone lengths and liver weights, considered in relation to lamb birth weights indicated that it was not a nutritional effect.

This study was undertaken at the Physiology Department, University of Queensland. It is a pleasure to thank Prof. W. V. Macfarlane for the valuable facilities, and for his help and encouragement.
Studies in the environmental physiology of cattle in Northern Rhodesia. I. The relation between the changes in the haemoglobin index with age and the development of the heat toleration coefficient
Authors: Walker C. A.
Published: March 2009

An investigation has been made on the changes in the haemoglobin index with age in four breeds of indigenous African and two breeds of European cattle.

1. Support is given to previous findings that the haemoglobin index was high and variable at birth and fell to an individual more stable adult level at between 2 and 3 years of age.

2. The haemoglobin levels for mature animals of the four tropical breeds are higher than mean figures quoted for other tropical cattle, but still fall within the ranges quoted.

3. The haemoglobin levels for the Friesian agreed with those quoted from temperate regions, but those for the Jersey were higher, agreeing most nearly with Jamaican figures. A reason for this is advanced.

4. The haemoglobin levels of the tropical breeds were significantly higher than those of the two temperate breeds examined.

5. Confirmation was given to the association of a high haemoglobin index with a high heat toleration coefficient.