bluuebunny/crossref_metadata_2025_split huggingface dataset:
The infestation of crops of oil-seed rape (Brassica napus L.) by insect pests
Authors: Free J. B. , Williams Ingrid H. 
Published: March 2009

SummaryDuring 3 years a total of ten crops of winter rape and two crops of spring rape were sampled for insect pests and pest damage once or twice a week from the green bud stage to just before harvest. The most common pests were Meligethes aeneusFab., and Ceutorhynchus assimilisPayk.; the former was usually the more numerous, especially on spring rape crops. Ceutorhynchus quadridensPanz. and Dasyneura brassicaeWinn. were less abundant. C. assimilisand M. aeneus immigrated to winter rape crops when temperatures exceeded 15 °C. Maximum infestation of M. aeneus occurred either at the green bud stage, or when flowering began or at full flower depending on temperature; maximum infestation of G. assimilis occurred during flowering, which varied in time from mid to late May. In response to changing temperatures successive waves of immigration sometimes occurred. Immigration to spring rape occurred at green bud stage.The two methods used for sampling pests, sweep nets and water traps, gave different results. Water trap collections primarily reflected pest flight, and were not necessarily related to the pest population on the crop.Ovary maturation of M. aeneus occurred between their emergence from hibernation and migration to winter rape. They began laying 3 weeks after their arrival on winter rape but immediately they arrived on spring rape. The proportion of male to female M. aeneus present on crops was variable. C. assimilis fed for 3–4 weeks after their arrival on winter rape before their ovaries developed and they mated.On both winter and spring rape the number of M. aeneus declined during flowering and that of C. assimilis declined while pods were maturing. Their decline on winter rape was associated with their emigration to new host plants. New generation M. aeneus emerged before winter and spring rape were harvested, and new generation C. assimilis emerged before spring rape but not winter rape was harvested.The implications of these findings are discussed in relation to pest control.
The effect of increased air movement on the heat production and emission of steers
Authors: Blaxter K. L. , Wainman F. W. 
Published: March 2009

1. Four steers were used in thirty-five experiments each lasting 4–5 days in which the effects of variation in air velocity from 0·4 to 1·6 m.p.h. at environmental temperatures of 0°, 10° and 20°C. on heat production were studied using a respiration chamber. Measurements were made on animals with winter coats and in the same animals after shearing.2. Standing time was increased by exposure to cold and slightly reduced by exposure to wind. The wind was so small that it had no effect on the measured coat depth. Piloerection increased winter coat depth by 30%. Heat production was increased by 17–20 kcal./hr. on standing.
Variation in growth and efficiency in twin calves
Authors: Taylor C. S. , Young G. B. 
Published: March 2009

Individual variation in the triple relationship of food intake, live weight and gain was examined in 40 twin calves. Appetite largely determined food intake.Regression analyses of fortnightly gain on protein and starch equivalent and mean weight are presented. Gain per lb. of P.E. or S.E. showed real but irregular changes from fortnight to fortnight. The food differential between heavier and lighter animals decreased during adaptation to new surroundings and diets.
Activity and energy expenditure in laying hens
Authors: Van Kampen M. 
Published: March 2009

SummaryThe energy cost of nesting activity and oviposition of hens in different environments has been determined.The oxygen consumption of hens on a wire floor reached a peak during the last 15 min before oviposition. However, the oxygen uptake of hens accustomed to a litter floor had fallen to a minimum at this time.The energy cost of expelling the egg is minimal. There is a good correlation between the locomotor activity and the heat production.The variations in heat production and body temperature on different types of floors are explicable by the differences in nesting activity.
Free amino -nitrogen used as a monitor for the uptake and movement of amino acids in sheep
Authors: Chalmers Margaret I. , Grant I. , Annand Maureen G. , White F. 
Published: March 2009

SummaryFree amino -N estimations were used to monitor the movement of amino acids in the vascular system of sheep. The net uptake of free amino-N by portal drained viscera was measured in whole blood and compared with the net gain in the plasma flow.In normally fed sheep eating dried grass, lucerne or silage the net gain of free amino -N in the plasma of portal blood contributed less than 80% to the total uptake in whole blood. When the protein component of the diet was added into the abomasum (casein supplement to a low nitrogen basal ration) the plasma contribution to the net gain in portal blood averaged 95%.The results suggest that the cells as well as the plasma are involved in the transport of amino acids in blood and that in ruminants all amino acids have to be measured in blood for a quantitative calculation of the absorption from portal drained viscera.
Growth and flowering of cotton (Gossypium hirsutumL.) as affected by daylength and temperature
Authors: Bhatt J. G. 
Published: March 2009

SummaryOver 14 h of daylight and high day temperature singly or in combination delayed flowering of the upland cotton J 34, whereas the photosensitive variety MCU 5 did not flower under long days alone or long days plus high temperature. These treatments promoted vegetative growth and made the plants tall and bushy. Though the treatments were discontinued 75 days after germination the subsequent reproductive growth was adversely affected with significant reduction in boll weight.The upland genotypes when grown at latitudes 29° N, 21° N and 11° N flowered progressively earlier and at lower nodes at more southerly latitudes because of reduction in daylength and temperatures. It is concluded that the upland cottons of northern India differ from classical types because daylength together with temperature appeared to determine flowering.
Comparison of direct drilling, reduced cultivation and ploughing on the growth of cereals
Authors: Elliott J. G. , Ellis F. B. , Pollard F. 
Published: March 2009

SummaryAn experiment on spring barley (cvs Impala and Julia) on sandy loam soil near Oxford was made from 1969 to 1973 to compare mouldboard ploughing, deep and shallow tined cultivation followed by conventional seed-bed preparation, and direct-drilling.In 1969 fewer barley plants on the direct-drilled plots than on cultivated plots gave fewer fertile ears/m2 and significantly less grain. In 1970, 1972 and 1973 yields did not differ between treatments. In 1971 there were more ears/m2 and more grain was obtained from direct-drilled than from ploughed plots. Mean grain yields over 5 years did not differ significantly between cultivation treatments. Ploughing and deep tine cultivation resulted in better shoot growth early in the season, more straw and more dicotyledonous weeds than direct-drilling. In comparable tillage operations on the same farm considerably less energy was needed for direct-drilling than for mouldboard ploughing and conventional seed-bed preparation.
Compensatory growth in immature sheep: III. Feed utilization by sheep subjected to feed deprivation followed by realimentation
Authors: Drew K. R. , Reid J. T. 
Published: March 2009

SUMMARYExperimental conditions and design were described in Part I. When compared with continuous growth, there was a 46% increase in rate of gain following refeeding, but no increase in intake per kg0·734 (MBS) per day. Part of the reason for this was the rapid accumulation of body water after realimentation. If the total cost of feed, including that of the weight-loss phase, is used to calculate the feed required per unit of gain, however, the sheep realimented at 26 kg to reach an empty body weight (EBW) of 45 kg had a requirement 27% higher than ad libitum continuously fed sheep taken to the same final EBW.The only treatment effect on digestibility or metabolizability of the diet that was not accounted for by level of intake was a depression immediately after underfeeding commenced. The metabolizable energy (ME) value later decreased markedly as a result of the relatively high proportion of gross energy lost in the urine (14·4%).There were no significant differences between normal growth and refeeding in maintenance requirement or efficiency of energy retention above maintenance. The combined figures were 107 ± 14 kcal ME/kg MBS/day and 52 ± 7% respectively.
Defoliation studies in hybrid maize: I. Grain yield, quality and leaf chemical composition
Authors: Singh R. P. , Nair K. P. P. 
Published: March 2009

SUMMARYIn order to examine whether high yield of maize could still be maintained at high plant densities by creating an ‘erectophile canopy’ through artificial defoliation of laminae, an experiment at Pantnagar, India, was made on the effect of density, stage and degree of defoliation in two divergent seasons, Kharif (rainy) and spring, of the year 1972. The defoliation treatments were either partial (clipping off the apical half of individual leaves) or complete (full leaf removal) and were imposed at three stages of plant growth, namely when 10 or 16 leaves were fully open or 12 days after silking. These treatments were applied at two plant densities, 60000 and 90000 plants/ha.Grain yield of maize increased significantly with the increase in population density in the spring season. The trend was diametrically opposite in the Kharif season. Defoliation at the 10th fully open leaf stage produced more grains than defoliating 12 days after silking, which in turn produced more than defoliating at the 16th fully open leaf stage, when plants were in full bloom. Increase in the degree of defoliation at the latter two stages of plant growth reduced grain yield, the effect being more at the 16th leaf stage. However, 50% defoliation at the 10th leaf stage increased grain yield in the Kharif season.The percentage protein content of grain declined with the increase in population density whereas increase in degree of defoliation increased the grain protein content. Higher protein content of grain was recorded in the spring than in the Kharif season. The leaf protein decreased as the plants neared maturity, especially at the higher degree of defoliation treatments.Sucrose and reducing sugars declined significantly with the increase in degree of defoliation. The reduction in sucrose was large enough to account for the reduction in total sugar percentage. Similar trends were observed in the sugar-to-protein ratio.
Teat shape associated with teat cup crawl and production in Friesian cows
Authors: Rathore A. K. 
Published: March 2009

SUMMARYA total of 580 Friesian cows from four dairy farms selected at random were grouped by teat shape. The incidence of teat cup crawl was recorded at the time of afternoon milking.Teat cup crawl was significantly higher (27·4%) in the cows with cylindrical shape teats than in cows with funnel shape teats (8·1%).Milk yield was significantly higher in the cows with funnel shape teats than in cows with cylindrical shape teats. There was significant reduction in milk yield due to teat cup crawl in both groups of cows, the reduction in milk yield being higher in the cows with cylindrical shape teats.
Effect of diets low in calcium and phosphorus on the development of growing lambs
Authors: Field A. C. , Suttle N. F. , Nisbet D. I. 
Published: March 2009

SUMMARYFive groups of four 8-week-old Blackface lambs were used to compare the effects of dietary deficiencies of calcium and/or phosphorus: four were given for 16 weeks a semi-purified diet low in Ca (0·07 %) and P (0·13 %), either unsupplemented (LCaLP) or supplemented with 0·3 % Ca (NCaLP), 0·3 % P (LCaNP) or both (NCaNP), and the remaining group was slaughtered initially.The only clinical abnormality observed was twisting of the forelegs in group LCaLP. Food intake was depressed by 26 % in LCaNP group, by 41·5 % in NCaLP group but was largely unaffected in group LCaLP. Apparent D.M. digestibility was lower for group NCaLP (57·7 %) than for other groups (61·2 %). Differences in live weight and body fat reflected the differences in food intake between treatments but the weights of fat-free body components were lowest in the groups given low P diets.The LCaNP diet decreased plasma Ca and increased plasma P but the NCaLP diet had the opposite effects. The LCaLP diet had no effect on plasma Ca and decreased plasma P less than the NCaLP diot.The three mineral deficient diets caused equally marked decreases in Ca and P retention but did not induce negative balances; they also impaired the quality of bone in the tibia and lumbar vertebra, by reducing both the amount of bone matrix and the degree to which it was mineralized, and produced histological lesions of rickets and osteoporosis. Diets low in P caused a marked fall in Mg content of the skeleton.Urolithiasis was common in lambs given diets adequate in P.
The question of grain content and forage quality in maize: comparisons between isogenic fertile and sterile plants
Authors: Bunting E. S. 
Published: March 2009

SUMMARYResults are presented from four experiments in which comparisons were made between isogenic sterile and fertile plants of maize to study the effects of grain content on yield and quality of shoot dry matter. In two experiments comparisons were made over a range of densities, extending from 5 to 25 plants/m2 in 1972 and 5 to 20 plants/m2 in 1973. The other two experiments, grown in 1974 at a density of 10 plants/m2, were sampled 30, 60 and 90 days after flowering.In 1972 and 1973 yield of shoot dry material was about 10% higher in fertile plants at the lowest density, 5 plants/m2, but grain formation had a negligible effect at higher densities. In 1974, at 10 plants/m2, the yield advantage for fertile plants was 6–7%. These results are in line with other European data, but show a much smaller effect of grain formation on shoot dry matter yield than is normally recorded in USA trials. The discrepancies probably reflect differences in environmental conditions.Absence of grain had little effect on contents of nitrogen, ash and in vitro digestible dry matter, and increased content of pepsin soluble material and hot water soluble carbohydrates. Percentage content of dry matter in the shoot was higher in fertile plants in 1973, and during the later stages of crop development in 1974.The results suggest that the importance attached to high grain content as an essential requirement for yield and quality in forage maize is exaggerated, and that the restriction of maize breeding and testing programmes to assessments of grain production, in the belief that the best grain varieties will also be best for forage, can no longer be justified in northern European countries.
Fatty acid composition of adipose tissue of Jersey cattle during growth and development
Authors: Leat W. M. F. 
Published: March 2009

SUMMARYThe effect of age on the fatty acid composition of depot fat of Jersey cattle has been investigated. Serial samples of subcutaneous fat were obtained by biopsy of the same animals from 3 months to 2 years of age. Samples of depot fat were also obtained from various anatomical locations of animals slaughtered between birth and 11 years of age.In subcutaneous fat at biopsy the percentage stearic acid remained constant to 1 year of age and then declined from 20% to 5% during the period 1–2 years post partum.In perinephric fat the stearic acid content increased from 10–15% at birth to 40% at 1 year of age, and then declined during the period 1–2 years post partum.Changes in the percentage stearic acid above the 10% level were accompanied by inverse change in octadecenoic (C18:1) acid, and below 10% mainly by change in hexadecenoic (C16:l) acid.There was a gradient of unsaturation between subcutaneous and internal body fats, and also within the subcutaneous fat itself.Evidence is presented to suggest that the decrease in the unsaturation of depot fat during the period 1–2 years post partum is associated with the deposition of more unsaturated fatty acids during the fattening phase of development.
The duration of the breeding season in Suffolk × Galway ewe lambs
Authors: Keane M. G. 
Published: March 2009

SUMMARYThe duration of the breeding season was studied in 33 Suffolk × Galway ewe lambs which had a mean live weight of 45·9 ± 1·4 kg. The mean dates of onset and cessation of oestrous activity were 8 November ± 1·4 days and 12 January ± 2·6 days, respectively. The mean number of heat periods exhibited was 4·37 0·3 and the duration of the breeding season was 81 ± 5·7 days. Only 18·2 % of animals had ≥ 6 heat periods while 45·5 % of animals had ≤ 3 heat periods. The incidence of silent heats was 9·2 %.
The development of plant components and their effects on the composition of fresh and ensiled forage maize: 3. The effect of grain content on milk production
Authors: Phipps R. H. , Weller R. F. , Fulford Rosemary J. 
Published: March 2009

SummaryMaize (Anjou 210), a density-sensitive genotype, was established at 5 and 15 plants/m2 and produced crops containing 50 and 26% grain respectively. Prior to ensiling, the high and low grain crops contained 6·9 and 20·4% water-soluble carbohydrates in the dry matter respectively and were reduced to 0·4 and 1·6% of the dry matter in the silage. The high grain silage contained a lower concentration of acid-detergent fibre, cellulose, lignin, cell-wall constituents and organic acids than the low grain silage. These differences were not reflected in the in vitro digestible organic matter in the dry matter values which were similar in both silages.Two groups of autumn-calving Freisian cows were offered either the high or low grain silage ad libitum as the sole forage plus an 18% crude protein concentrate during a 14-week experimental period. The cows which received the high grain silage produced significantly more milk of a significantly lower milk fat content than the cows which received the low grain silage.The increased milk production coupled with the smaller loss of water-soluble carbohydrates during ensiling show that a high grain content in forage maize is a desirable attribute. It is suggested that density tolerance should be one of the selection criteria used by plant breeders to allow crops to be established at high plant densities from which near maximum dry-matter yields could be obtained, while still containing a high proportion of grain.
Effects of feeding ryegrass of varying maturity on the metabolism and composition of lipids in the rumen of sheep
Authors: Gerson T. , John A. , King A. S. D. 
Published: March 2009

SummaryTwo experiments were carried out to test the effects of ryegrass maturity on rumen lipid metabolism. In the first experiment the effect of stage of maturity of perennial ryegrass on lipid metabolism in the rumen was studied with grazing sheep fitted with rumen cannulae. The pasture was either immature (13·8% crude protein), mature (8·1% crude protein) or senescent (5·5% crude protein).The ratesin vitroof triacyl glycerol lipolysis and linoleic acid (18: 2w6) hydrogenation were found to decrease with increasing age of the ryegrass.In the second experiment the sheep were dosed with emulsified linseed oil (30 g) via rumen cannulae while grazing immature or senescent ryegrass and the rumen digesta and blood plasma sampled at 0, 4 and 8 h after dosing.The proportions of linseed oil retained in the rumen were greater and blood plasma linoleic (18:2w6) and linolenic (18:3w3) acid concentrations higher when senescent ryegrass was fed.It was concluded that the rates of rumen lipolysis and hydrogenation decreased with the age of pasture and that after dosing with linseed oil the polyunsaturated fatty acid concentrations in blood plasma increased.
The effect of interval between harvests and nitrogen application on the concentration of nitrate-nitrogen in the total herbage, green leaf and ‘stem’ of grasses
Authors: Wilman D. , Wright P. T. 
Published: March 2009

SummaryThe effect of six intervals between harvests and three levels of N application on the concentration of nitrate-N and total N in total herbage, green leaf and ‘stem’ was studied in two varieties of perennial ryegrass during 30-week periods in each of the first two harvest years of a field experiment. The effect of two intervals between harvests on the concentration of nitrate-N in Italian ryegrass total herbage was studied in the same experiment. The effect of two intervals between harvests and three levels of N application on the concentrations of nitrate-N and total N in total herbage was studied in five grasses during a 32-week period in a second field experiment.Increasing the interval between harvests tended to increase the concentration of nitrate-N in herbage; however, this seemed due mainly to the average date of harvest being later in the year with the longer intervals. The concentration of nitrate-N in herbage increased from June to September. Italian and hybrid ryegrass and tall fescue were much higher than perennial ryegrass in nitrate-N concentration at the highest level of applied N (525 kgN/ha per year). Apart from the species and time of year effects, the nitrate-N concentration seemed to be determined mainly by the amount of N applied divided by the number of days between the date of application and the date of sampling. The ‘stem’ of perennial ryegrasa tended to be slightly higher in nitrate-N concentration than green leaf. The proportion of nitrate-N in total N was increased by increasing the interval between harvests and by applying N and was nearly twice as high in ‘stem’ as in green leaf. Both the nitrate-N and the total N concentration of herbage, particularly the latter, seemed to be inversely related to solar radiation receipt.
The relationship of soil mineral NO3-N with stem NO3-N concentration, and of fertilizer-N with the amount of nitrogen taken up by winter wheat, in experiments testing nitrogen fertilizer in combination with aphicide and fungicides, from 1980 to 1982
Authors: Darby R. J. , Widdowson F. V. , Bird E. , Hewitt M. V. 
Published: March 2009

SummaryExperiments on winter wheat were made from 1980 to 1982 to test fungicide and aphicide sprays in factorial combination with four amounts of nitrogen fertilizer, applied in either one or two dressings in spring. The wheat was grown on three farms with contrasting calcareous clay soils from three soil series; each year it followed a 2-year break on one farm, a cereal rotation on the second and continuous wheat on the third. Soils were sampled to a depth of 0·9 m at seedling emergence in autumn, and again in February and April, to determine the NO3-N and NH4-N in each 0·3 m horizon. Crops were sampled for growth analysis at monthly intervals from March onwards and analysed for nitrogen content. Measurements of stem sap NO3-N concentration were also made at 2-weekly intervals from February or March to late June.Measurements of soil mineral N were used to calculate the fertilizer nitrogen dressings used in the experiments. The concentration of NO3-N in the stem sap was related to NO3-N in soil; concentiations remained high until most of the soil NO3-N had been removed by the crop. The time at which stem sap NO3-N concentration declined therefore acted as an index of soil N supply, and the data showed that fertilizer-N was needed when the NO3-N concentration fell below a 200 μg/ml threshold. Yields benefited from N applied in February or March only when stem sap NO3-N concentration fell below the threshold at this time.Apparent fertilizer nitrogen efficiency exceeded 70 % where yields were very large, but ranged between 53 and 64% where yields were smaller because either soil physical problems or disease restraints were present.A severe attack by take-all (Gaeumannomyces cerealis) caused premature senescence at one centre in 1980; this apparently prevented previously assimilated nitrogen from moving into the grain.