bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SUMMARYUltrasonically 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

SUMMARYA 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

SUMMARYA 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 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

SUMMARYThe 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

SUMMARYCold 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

SUMMARYThe 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

SUMMARYIn 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

SUMMARYThe 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

SUMMARYThe 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.
Spacing and harvest date experiments with Maris Peer potatoes
Authors: Gray D. 
Published: March 2009

SUMMARYIn 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.
Utilization of grass-silage nitrogen by growing sheep
Authors: Grenet Elisabeth 
Published: March 2009

SUMMARYThe 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

SUMMARYTwenty-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

SUMMARYBean 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

SUMMARYIn 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.