bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of sunflower cultivars to plant density and nitrogen
Authors: Narwal S. S. , Malik D. S. 
Published: March 2009

SummaryIn a 2-year study, sunflower oultivar EC 69874 produced greater leaf area than EC 68415, but gave similar grain yields. The former was superior in leaf area, head size and yield per plant but was inferior in 100-seed weight. The leaf area was greater at lower plant density (5·5 plants/m2), which resulted in higher 100-seed weight, number of seeds per plant and yield per plant than higher plant density (11·1 plants/m2). Plant density had no influence on the percentage of filled seeds or oil content. Application of nitrogen improved the leaf area, flowerhead size, percentage of filled seeds, 100-seed weight, yield per plant and grain yield up to 60 kg/ha but decreased the oil content.
Effects of applied nitrogen on grass yield, nitrogen content, tillers and leaves in field swards
Authors: Wilman D. , Pearse P. Joy 
Published: March 2009

SummaryEffects of three levels of N application and four intervals between harvests on field swards of perennial ryegrass (Lolium perenne L.) were studied during 6-week periods in summer and spring. Ryegrass was compared with tall fescue (Festuca arundinacea Schreb.) in spring and autumn.An increase in the interval between harvests from 1 to 6 weeks allowed a larger, positive response to applied N to develop in respect of dry-matter yield, weight per tiller, and leaf blade and sheath length. Response to N was expressed more in terms of larger leaf blades than in a larger number of tillers. Tall fescue leaf blade size was increased more than that of ryegrass by a period of uninterrupted growth in May.Within 1 week of its application, N had increased the N content of both emerging and dying leaf blades and had increased the width and reduced the weight per unit area of the emerging blades. The positive effect of N on blade width (and on blade length where uninterrupted growth was allowed) and its negative effect on weight per unit area were ‘carried through’ the sward, to be recorded a second time when that generation of blades had become the dying blades.Applied N increased the number of tillers, the rate of emergence of new tillers, the proportion of tiller buds which developed into tillers, and the proportion of relatively young tiller buds which developed.
Breed structure in the pedigree Ayrshire cattle population in Great Britain
Authors: Wiener G. 
Published: March 2009

Ayrshire Cattle Herd Booksfor the years 1927, 1946 and 1947 were examined to study the breed structure. Extended pedigrees of a sample of registered females showed that more than half their genes had come from eight herds. Most of the genetic contribution of these herds comes through the bulls they breed.Herds were divided into: breeders' herds (a), breeders' herds (b), multipliers' herds (i), multipliers' herds (ii), and herds registering males only. The function and numerical importance of each group is shown. The position of any one herd in the breed hierarchy is unstable. Changes in the extent of specialization of herd function between 1927 and 1946 are described.The Ayrshire breed structure is discussed in the light of its implications on the effective size (N) of the population and on the selection of bulls for breeding.
Breed differences in copper metabolism in sheep
Authors: Wiener G. , Suttle N. F. , Field A. C. , Herbert J. G. , Woolliams J. A. 
Published: March 2009

SUMMARYEvidence was sought for genetic differences in the absorption or systemic use of copper by comparing responses in plasma Cu concentration to oral and intravenous Cu repletion. Lambs of the North Ronaldsay (Orkney), Scottish Blackface and Welsh Mountain breeds and crosses of these with the North Ronaldsay were used.In two oral repletion phases average Cu intakes/kg live weight were 0·87 and 0·63 mg/week and similar for all breed groups. Plasma Cu concentrations of Scottish Blackface lambs showed little or no increase while those of North Ronaldsay lambs increased rapidly, and those of Welsh Mountain lambs increased moderately. The plasma Cu concentrations of the cross-breds increased more rapidly in the first than in the second phase; their rate of change lay between the pure breeds but was closer to that of the North Ronaldsay in the first phase.The rates of increase in plasma Cu concentration during intravenous repletion were relatively uniform for the different breeds and crosses except the Blackface which showed a lower rate. It was concluded that the large differences between groups in response to oral Cu repletion were largely attributable to differences in the efficiency of Cu absorption.
Inter-plot competition in variety trials of field beans (Vicia fabaL.)
Authors: Kempton R. A. , Lockwood G. 
Published: March 2009

SUMMARYFour trials were carried out to investigate the effect of inter-plot competition on seed yield and plant height of field beans using experimental designs balanced for neighbours. One trial tested four varieties ranging in final height from 25 to 100 cm and sown in four-row plots with 30 cm spacing between rows and one blank row between plots. When grown between plots of a dwarf variety, the plot yield of the tallest variety was increased by 20% compared with its pure stand yield: a complementary reduction in yield was shown by the dwarf variety when grown between plots of the tall. The effect on the yield of the inner rows of the plot was somewhat smaller than that of the outer rows but still significant. Another trial with six commercial varieties differing in final height by less than 15 cm showed no differential effects of inter-varietal competition on yield. In two trials with six varieties of widely differing heights planted with 50 cm spacing between rows, but no gap between plots, plot yield was strongly affected by the neighbouring variety in the trial with single-row plots, while yields from the four-row trial showed a large interaction between variety and inner and outer row position, again indicative of inter-variety competition. The yield response to competition could be described by a common linear regression on the excess height of plot neighbours: there was little evidence of varietal differences in sensitivity or aggressiveness.Plant height showed a positive response to height of plot neighbours in all four trials, whilst in the single-row trial, the ratio of grain yield to total dry-matter production (harvest index) was negatively related to excess height of neighbours.The results suggest that, when testing varieties differing in height by more than 20 cm, at least two buffer rows, e.g. six-row plots with the centre two rows harvested, are required to obtain a true comparison of pure-stand yield. Alternatively, when this procedure would result in an unacceptable use of resources, one of the statistical models adapted in this paper may be used to adjust variety yields for pure stands.
Evaluation of the performance of cassava (Manihot esculenta Crantz) when grown from inverted stem cuttings
Authors: Onwueme I. C. 
Published: March 2009

SUMMARYIn order to investigate the characteristics of inverted cassava plantings, seven-node cuttings were planted upright or inverted, and such that four nodes of each cutting were within the soil in a glasshouse. They were observed for 7 weeks. The inverted cuttings sprouted less rapidly, but the percentage of the cuttings which eventually sprouted was not decreased. The inverted cuttings produced more sprouts than the upright ones, and a greater percentage of their sprouts were produced below ground than for the upright cuttings. At 5 and 7 weeks, the total leaf area per cutting was less for the inverted cuttings. The number of leaves per cutting did not differ between the treatments.In a field experiment comparing upright and inverted stem pieces, field emergence and tubering were slower in the inverted cuttings. Yield per plant and per unit area was significantly lower for the inverted cuttings. In the upright planting, most of the tubers originated at the lowest extremity of the cutting and formed a compact bunch there. For the inverted planting, most of the tubers arose from the shallower-lying submerged nodes, but the tubers did not form a compact bunch. The inverted planting had a lower percentage of its tubers lying along the ridge. In a few of the inverted plantings, but not in the upright, the bases of some stems became tuberous. The treatments did not differ with respect to mean tuber length, radius of spread of the tuber tip, and the number of major stems per plant.
Some preliminary observations on the histological development of the fore-stomachs of the lamb I. Histological changes due to age in the period from 46 days of foetal life to 77 days of post-natal life
Authors: Wardrop I. D. 
Published: March 2009

1. A general survey of the histological changes of the fore-stomachs of the lambs from 46 days of foetal life to 77 days of post-natal life is presented.2. In all the rumen foetal specimens the mucosal surface was smooth. At birth small, conical papillae were visible and from this age onwards these papillae increased rapidly in size and tended to be long and tongue-shaped in appearance. Little change occurred in the appearance of the rumen papillae after 56 days of age.3. The outlines of the reticulum reticular ribs were visible in the 100-day-old foetal specimen. At birth the normal honeycomb-like structure of the reticulum was well developed, but the papillae on and between the reticular ribs were small and had rounded tips. From 20 days of age onwards the reticulum features increased in size and the papillae became pointed in shape.4. At 46 days of foetal life the omasum wall was folded to form developing laminae and by 70 days of foetal life laminae of four orders were present. The main age changes in the appearance of the mucosal surface from this age onward was an increase in the length of the laminae, the formation of small conical papillae on the laminae, and an increase in the inter-laminae spaces.5. All three fore-stomachs showed the same general histological changes with age. The epithelium changed from a stratified cuboidal type in the foetal specimens to a keratinized, stratified, squamous epithelium in the post-natal specimens. The basal layer of the epithelium became folded to form papillae, reticular ribs and laminae, and in the rumen and reticulum further folding of this layer took place to form papillary bodies.
Some preliminary observations on the histological development of the fore-stomachs of the lamb II. The effects of diet on the histological development of the fore-stomachs of the lamb during post-natal life
Authors: Wardrop I. D. 
Published: March 2009

1. A study on the effects of the type of diet on the histological development of the fore-stomachs of the lamb is presented.2. The rumen papillae were well developed in a 7-week-old lamb that had been fed solely on milk from birth, but compared to a lamb of the same age that had access to lucerne chaff from birth, they were smaller in size and more conical in shape. There was no difference in the appearance of the rumen mucosal surfaces of two lambs of 13 weeks of age, one of which had access to lucerne chaff from birth and the other access to lucerne chaff for only 4 weeks prior to slaughter.3. The type of diet appeared to have little effect on the appearance of the reticulum mucosal surface.4. The appearance of the omasum mucosal surface was only normal when lucerne chaff was fed to lambs.5. The histology of the rumen wall was normal in the milk-fed lamb. However, compared to the lamb of the same age that had been fed on lucerne chaff, the papillary body formation, stratum granulosum and stratum corneum were less well developed.6. Apart from a thinner stratum granulosum and stratum corneum, the histology of the reticulum wall of the milk-fed lamb was little different from that of the lamb of the same age that had been fed on lucerne chaff.7. The histology of the omasum wall of the 7-week-old milk-fed lamb was very similar to that found in the lamb at birth.
Laboratory and field evaluation of certain pesticides against the adults and eggs ofTetranychus cinnabarinusBoisduval on cotton
Authors: Marei A. S. M. , Saad A. S. A. , Tantawy G. 
Published: March 2009

SUMMARYThe effectiveness of certain pesticides a ainst adults and eggs ofTetranychus cinnabarinusBoisduval infesting cotton was sti died. Kelthane S and Rogor gave the best performance in the field evaluation, whilu Kelthane, Dursban and Cyolane were best in the laboratory evaluation. Specific acaricides were generally more toxic than the other insecticides on both adults and eggs of the mite. The slide-dip method was more sensitive for testing Kelthane, Dursban and Cyolane.
Irrigating seedling tea in Southern Tanzania: effects on total yields, distribution of yield and water use
Authors: Carr M. K. V. 
Published: March 2009

SUMMARYIn a dry area of Southern Tanzania with a single rainy season irrigation during the six-month-long dry season (May-November) doubled the total annual yield of tea and at the same time evened its distribution over the year to some extent. Other factors including low temperatures limited growth rates during the period June-September despite irrigation, whilst a lull in production in November appeared to be unrelated to external factors. Roots were traced to depths of about 4·3 m and by the end of the dry season unirrigated bushes were drying the soil below 3m. In general total yields decreased with decreasing frequency of irrigation and quantity of water applied but because these plants were deep rooting they could withstand deficits up to 100 mm without a reduction in yield, equivalent to a loss of about 25% of the total available water in the profile. There was some evidence that the most economical use of water occurred when the soil was not rewetted to field capacity at each irrigation, although yields were then less. Irrigation also reduced the incidence of a stem canker,Phomopsis theae. The implications of these results to the tea industry of East Africa are discussed.
Changes in the availability of dietary copper to young lambs associated with age and weaning
Authors: Suttle N. F. 
Published: March 2009

SUMMARY64Cu and an indigestible 103Ru-labelled marker were administered into the alimentary tract of six artificially reared lambs on four occasions, 28 and 14 days before weaning and 15 and 42 days after weaning. The ratio of 64Cu: 103Ru excreted in the faeces was used to measure the apparent availability of Cu.Mean Cu availability decreased from 71·0 ± 3·7 to 47·2 ± 7·8% immediately before weaning and to 10·8 ± 1·4% 15 days after weaning.The relationship between availability (y, %) and age (x, days) prior to weaning was described by the equationWhen half of the lambs were given abomasal doses of 64Cu + 103Ru 42 days after weaning, the mean Cu availability was 21·4±4·0% compared with 3·7±2·1% for those dosed via the rumen.64Cu present in the whole plasma volume 20 h after dosing (y, % dose) was highly correlated with availability (x, %), the equation beingFour out of a group of eight milk-fed lambs were given access to a proprietary concentrate from birth and milk intake was progressively restricted so that by 15–21 days they were wholly dependent on the concentrate. Mean Cu availability at 23 days was 8·3±3·4% compared with 75·0±5·4% for lambs continuing to receive milk substitute alone. The corresponding values for 64Cu in plasma were 0·34±0·03 and 1·41±0·14% dose.Less than 1·1% of the 103Ru and 64Cu doses were excreted in the urine after 48 h and no 103Ru was detected in the plasma.The nutritional significance of and mechanisms for the reductions in Cu availability with age and weaning are discussed and methods for measuring Cu availability compared.
The ‘teat order’ of suckling pigs: I. Relation to birth weight and subsequent growth
Authors: Fraser D. , Jones R. Morley 
Published: March 2009

SUMMARYTeat orders were determined for 76 litters of Large White and Large White × Landrace pigs. Regression analysis within litters revealed a relationship between suckling position and weight both at birth (P<0·01) and at 3 weeks of age (P<0·001), with the heavier piglets tending to occupy the more anterior teats. The correlation coefficients, however, were very small (r = –0·16 and –0·22 respectively). The correlation between birth weight and 3-week weight was much larger (r = +0·47); and a comparison of pairs of litter-mates showed that a difference in birth weight of 0·25 kg or more persisted at 3 weeks in the majority of cases, regardless of which piglet suckled the more anterior teat. Birth weight accounted for much more of the variation in 3-week weight than did teat number, and, when the effect of birth weight had been taken into account, teat number accounted for only an additional 2·3% of the variation. Even so, the anterior teats did appear to confer some advantage which was independent of that of the birth weight of the piglets suckling these teats. From the results of this and other studies it is concluded that there is only a weak relationship between suckling position and weight at birth and 3 weeks. Other unidentified factors are probably of more importance for the within-litter variation in weight gain of suckling pigs.
A study of feeding types and certain rumen functions in six species of South African wild ruminants
Authors: Giesecke D. , Gylswyk N. O. Van 
Published: March 2009

SUMMARYIn order to characterize the rumen digestive physiology of South African wild ruminants investigations were made on a total of 35 individuals of six species killed in various regions during the dry season.In buffalo, blue wildebeest and gemsbok grasses constituted 85–100% and in impala, springbok and kuduless than 10% of the diet. In the case of the latter three species effects of the habitat and of predilection for certain plant materials were apparent.Compared with the grazers, the species feeding mainly on plant material other than grass were characterized by a smaller physiological capacity of the rumen reticulum, higher counts of ciliate protozoa and ‘large bacteria’, higher levels of rumen ammonia and higher molar proportions of rumen propionate and valerate. Within these feeding types differences between species were indicated.
Variation in plasticity within the S. 23 cultivar of Lolium perenne L.
Authors: Valentine J. , Charles A. H. 
Published: March 2009

SUMMARYThe S. 23 cultivar of Lolium perenne L. has the ability to perform well in a wide range of environments and an experiment was designed to examine the phenotypic plasticity of S. 23 genotypes with particular reference to the level of nitrogen application.Genotypes of S. 23 grown in a controlled growth room at close spacing (5 cm) showed a wide range of dry-matter yields with the highest yielding 144 times that of the lowest at the last of six cuts taken at 4-week intervals. Genotypes maintained much the same order of yield from one nitrogen level to another, but there were exceptions. Regression techniques were used to further quantify genotype-environment behaviour and to measure response to the environment in which the plants were grown. Considerable variation in this character occurred and the correlation of mean yield and response was incomplete. Some of the genotypes combined the desirable characters of high mean yield and good response to improved environments, while others had high mean yields, but were not as well adapted to the highest N level.In the experiment no significant effects could be traced to differences in age of seed, but plants which had been maintained vegetatively for 7 years showed reduced vigour.
Variation in methane production by sheep fed every two hours
Authors: Mathers J. C. , Walters D. E. 
Published: March 2009

SUMMARYFour sheep were maintained on a pelleted diet based on barley straw, sunflower-seed meal and barley which was offered at 2 h intervals by mechanical feeders. In each of two periods approximately 3 weeks apart, methane production was measured continuously for 6 h in each animal. Despite the frequent feeding regime, methane output varied markedly with time increasing after feeding and then declining. Serial correlation analysis indicated a rhythmical variation of period 2 h which was confirmed by Fourier series analysis for all but one data set. The observations suggest that even with frequent feeding, there is considerable deviation from steady state in the rate of carbohydrate fermentation in the rumen.
The effects of cattle slurry and inorganic nitrogen fertilizer on the yield and quality of spring barley
Authors: Pain B. F. , Richardsonf S. J. , Fulford Rosemary J. 
Published: March 2009

SummaryIn experiments over 3 years (1974–6) cow slurry in the range 0–112·5 t/ha and ammonium nitrate in the range 0–120 kg N/ha were applied to field plots factorially to test the effects on the yield and quality of spring barley grain.In 1974 slurry application markedly improved the grain yield (cv. Golden Promise) at each rate of inorganic N and increased grain size. Applying N fertilizer with more than 37·5 t slurry/ha reduced grain yield below the maximum. Grain with the highest crude protein content (15·1 %) was obtained from a combination of slurry and inorganic N. The residual effects of the slurry treatments gave satisfactory grain yields in 1975 without additional fertilizer.Grain yields (cvs Julia and Abacus) in other experiments carried out on a different soil type in 1975 and 1976 were approximately half those obtained in 1974, due in part to drought conditions. The pattern of the results was similar. Heaviest grain yields were harvested from plots receiving 70 t slurry/ha with no additional N.
Relationship between bacteria and ciliate protozoa in the rumen of sheep fed on a purified diet
Authors: Kurihara Y. , Takechi T. , Shibata F. 
Published: March 2009

SummaryTwo sheep, with and without ciliate protozoa, were fed on a wood-pulp cellulose, corn starch, soya-bean protein diet and the microbiological and chemical characteristics of the rumen ingesta of both sheep were studied. The purified diet led to a simplified rumen flora enabling some deductions to be made about the interactions of the principal bacterial species and their interactions with the protozoa in relationship to the biochemical analysis of the rumen. Ammonia concentrations were similarly low in each animal. Total volatile fatty acid concentrations were higher in the faunated sheep though the proportion of propionic acid was highest in the unfaunated sheep. Cellulose digestion in the faunated rumen was about twice that in the unfaunated one. Total bacterial concentrations in the unfaunated rumen were over twice those in the faunated rumen, but the numbers of cellulolytic bacteria were higher in the latter while the numbers of amylolytic bacteria were higher in the unfaunated rumen. The principal species of bacteria differed in the two rumens.
Block designs for variety trials
Authors: Patterson H. D. , Williams E. R. , Hunter E. A. 
Published: March 2009

SummaryIn this paper we present a series of resolvable incomplete block designs suitable for variety trials with any number of varieties v in the range 20 ≤v ≤ 100. These designs usefully supplement existing square and rectangular lattices. They are not necessarily optimal in the sense of having smallest possible variances but their efficiencies are known to be high.