bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of reproductive development upon the root system of perennial ryegrass and some effects upon herbage production
Authors: Troughton A. 
Published: March 2009

SUMMARYThe production of flowers in perennial ryegrass (Lolium perenne) has been associated with a reduction in root relative to shoot growth and the post-flowering period with the death of roots. Any effect that reproductive development has upon the root system does not appear to adversely affect subsequent shoot growth. In the present experiments, vernalized plants restricted to root axes present prior to flowering showed little difference in herbage production and length of life compared with unvernalized plants similarly restricted. Flower production did, however, limit the ability of plants to initiate main root axes. It would seem unlikely that the mid-summer depression of herbage growth is due to the effect of reproductive development upon the root system.
The production and utilization of winter grass
Authors: Hughes G. Pearson 
Published: March 2009

The investigations that have been in progress at the Grassland Research Station, Stratford-on-Avon, on the management of grassland for the production of winter pasturage are discussed as four experiments, E 62, E117, E 86 and E158.Exp. E 62 was concerned solely with herbage production, while the remaining three have taken into account the performance of the beef animal under such pasture treatment.The maintenance of condition in the animal has proved possible over a number of winter seasons from 1948 to 1953, sufficiently so to warrant investigation of the means of providing as abundant pasturage as possible at this time of year from latesummer and autumn rested swards. The importance of integrating a system of winter utilization with summer production has become evident in the course of the work, and the necessity of upkeeping sward condition, more especially the grass-legume balance, has been realized. The use of alternate drills of grass and lucerne shows considerable promise in this respect. Intensive utilization and production has taken place from such seedings at all seasons without serious sward deterioration.The development of a grazing system for outwintering cattle destined to be fattened on summer pastures would provide a means whereby such cattle would be fed with as little attention and labour demand as is consistent with good stock management. With the need for cheapening of costs in beef production methods in Britain attention might well be paid to the methods outlined in the light of the experimental data presented.
Fertility in Clun Forest sheep
Authors: Williams S. M. 
Published: March 2009

The ages of the Clun ewes considered in the survey were ranged from between 1 and 4 years in practicbreeding ally every case. They had thus not attained their maximum fertility which probably occurs at the age of from 4 to 6 years. A consideration of the fertility in the breeding flocks does not provide an estimate of the maximum for this breed, which can only be obtained from older draft ewes which are used in crossbreeding flocks with the object of fat lamb production.Barrenness is relatively unimportant in ewes, but affects approximately one-third of all breeding ewe lambs each year. Abortion was insignificant amongst ewes but was more common amongst ewe lambs.
The effect of season on the composition of the blood of lactating and non-lactating cows as revealed from repeated metabolic profile tests on 24 dairy herds
Authors: Rowlands G. J. , Little W. , Manston R. , Dew Sally M. 
Published: March 2009

SUMMARYBlood samples were taken from groups of lactating and non-lactating cows on three occasions from each of 24 commercial dairy herds sampled eight herds at a time at 6-weekly intervals throughout 1972. The blood samples were analysed for packed cell volume, blood glucose and haemoglobin, and for the serum concentrations of albumin, total protein, urea nitrogen, Ca, inorganic phosphate, Mg, K, Na, Cu, and Fe.Clear seasonal patterns were evident for packed cell volume and the mean concentrations of urea nitrogen and haemoglobin each of which were highest during the summer months. The effect of season on the concentrations of the other constituents was smaller. Mean values of packed cell volume, haemoglobin and Fe were consistently higher in the non-lactating cows than in the lactating cows. Mean concentrations of Mg were lower in the blood of non-lactating cows throughout the year; Cu concentrations followed a similar trend in the autumn and winter.There was evidence of overall herd differences regardless of season, in particular for Cu, globulin, Fe and urea nitrogen concentrations.
The effect of sodium chloride supplementation of a sodium adequate hay on digestion, production and mineral nutrition in sheep
Authors: Moseley G. , Jones D. I. H. 
Published: March 2009

SUMMARYFour groups of six 18-month-old wethers were fed a diet of hay ad libitum with a pelleted ground barley supplement for 70 days. The control group received no further dietary supplements and the sodium content (0·46%) was above that recommended by published standards. Groups 2, 3 and 4 received supplements of sodium chloride, mixed and pelleted with the barley, to provide a final dietary concentration of 1·7, 2·5 and 3·1% sodium respectively.Dry-matter intake, dry organic-matter intake and digestible organic matter in dry matter (DOMD) were significantly reduced (P < 0·01) at the highest sodium intake. There was a reduction in live-weight gain and efficiency of utilization of digestible organic matter with increasing sodium chloride supplementation, with significant differences (P < 0·05) between the highest and lowest sodium intake groups.There were no consistent or significant changes in the serum concentrations of sodium or potassium following sodium chloride supplementation, but serum calcium and magnesium levels were significantly lowered as a result of sodium chloride supplementation.Sodium chloride supplementation improved the apparent availability of sodium, potassium, magnesium and calcium but reduced that of phosphorus and nitrogen. The retention of Na, K, Mg, P and N was lower at the highest sodium intake but Ca retention was higher. Urine volume and excretion of Na, K, Mg, Ca, P and N increased with sodium chloride intake.
Production and survival of tillers of wheat and their contribution to yield
Authors: Ishag H. M. , Taha M. B. 
Published: March 2009

SUMMARYThe effect of sowing date and nitrogen on tillering patterns, survival and contribution of reproductive tillers to grain yield of standard and Mexican wheat cultivars were studied for two seasons.Maximum number of tillers/plant, 3·2–4·5, was observed after 40 and 27 days from sowing for 1970–1 and 1971–2 respectively. The number of ears/plant was 1·4 at the end of the growing season. Varieties differed in tillering, and LRN10 and Giza 155 produced more reproductive tillers than Falchetto and Mexipak. Nitrogen application increased tillering efficiency, i.e. ratio of fertile to total tillers produced. Only 26% of tillers appearing in the axil of the first true leaf (T1) and 10% of tillers in the axil of the second true leaf (T2) survived to produce ears. The high mortality of tillers was attributed to high air temperature prevailing during the growth period (33 °C by day; 18 °C by night). Eared tillers did not die and were self supporting because of the photosynthesis by the ear.Grain weight/tiller was positively correlated with tiller dry weight at heading, r= 0·76–0·96. Main shoots contributed about 81% of the total grain yield and 19% came from T1 and T2 tillers.
Crop–weed competition studies in groundnut (Arachis hypogaea L.)
Authors: Yadav S. K. , Singh S. P. , Bhan V. M. 
Published: March 2009

SUMMARYField experiments were made during the rainy seasons of 1979 and 1980 at Hissar, India, to study the effect of time of weed removal on the yield of groundnut. Removing weeds from 2 to 8 weeks after sowing led to significantly larger yields than that of plots which were not weeded. Maximum pod yield in both years was obtained when weeds were removed 4 weeks after crop sowing.
Effects of applied nitrogen on grass leaf initiation, development and death in field swards
Authors: Joy Pearse P. , Wilman D. 
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.The application of N increased the rate of production of leaf primordia, the number of leaf primordia per tiller, the length of the shoot apex, the rate of development of primordia into unemerged leaves, the number of leaves emerging, the number of live, emerged leaves per tiller, the leaf extension rate and weight of blade emerging and the net gain, per tiller per day, in blade length and weight. The application of N tended to reduce the number of unemerged leaves per tiller and the length of apex per primordium. Applied N retarded leaf death (whether measured as numbers, length or weight) during the first 2–3 weeks after application and accelerated death subsequently. During the 1st week of the summer periods, the net gain in green blade length and weight per tiller was doubled by 22 kg N/ha and trebled by 66 kg N (compared with nil). During the final fortnight of the summer periods, the net gain in green blade length and weight was less with the 6-than with the 3- or 2-week interval, and, in the case of the 6-week interval, the positive effect of applied N on the rate of development of primordia into unemerged leaves and on the number of leaves emerging had been lost.The ryegrass had more leaf primordia and unemerged leaves per tiller than the fescue, and a faster rate of development of primordia into unemerged leaves and of unemerged into emerged leaves.A ryegrass leaf spent a broadly similar length of time in each of the three stages, primordium, unemerged leaf and fully expanded live leaf, and about half as long as one of those stages as an emerging leaf. At nil N a leaf developed to about 6000 times its starting length (as a newly-formed primordium) in 67 days in summer; at high N a leaf developed to about 10500 times its starting length in 53 days. The percentage increase in length per day was greatest during the unemerged leaf stage.
The reaction of celery (Apium graveolens L.) to infection by celery mosaic virus
Authors: Walkey D. G. A. , Ward C. M. 
Published: March 2009

SUMMARYCommercial Celery Cultivars Varied in their response to inoculation by celery mosaic virus. The most severe symptoms occurred in self-blanching cultivars, but a high level of resistance was found in some non self-blanching cultivars such as Solid White and Fordhook. The resistance in these cultivars was confirmed in glasshouse tests.
Population studies with wheat: II. Propinquity
Authors: Hudson H. G. 
Published: March 2009

An investigation of the problem of propinquity has shown that the yield of any unit of 6 in. of drill row of wheat is significantly affected by the number of plants in adjacent units. The “competition correlation”, which measures the intensity of this effect, is greatest with medium plant densities, and low and often insignificant for units of high or low plant density.Competition is primarily underground for water, soil nutriments and soil air; of these, competition for water is most important in determining yield.
Dietary protein content and the subsequent body composition and food intake of pigs
Authors: Wyllie D. , Owen J. B. 
Published: March 2009

SUMMARYForty Large White × Wessex pigs were fed from 7 to 27 kg live weight, on diets containing either 28 or 14% crude protein. From 27 to 113 kg live weight the pigs were fed a common dietad libitum. Pigs from each treatment were killed at 27, 54, 82 and 113 kg live weight and the chemical composition was determined. From 7 to 27 kg and from 27 to 113 kg live weight, daily gain, food intake and food conversion efficiency were similar for the two treatments.At 27 kg, pigs on the lower protein diet were fatter and contained less lean tissue. Between 27 and 54 kg live weight the pigs previously on the higher protein diet deposited a much greater amount of fat than the pigs on the lower protein diet, so that by 54 kg the pigs initially on the lower protein contained less fat. At 82 and 113 kg live weight the pigs given the lower protein diet initially also tended to contain less fat. These findings are discussed with particular reference to the voluntary energy intake of growing pigs.
Palatability of cross-bred beef
Authors: Moore V. J. , Bass J. J. 
Published: March 2009

SUMMARYThe effect on palatability of crossing Angus with other beef breeds has been studied. Purebred Angus and Jersey × Angus crosses were significantly more tender and of a higher general acceptability than the Simmental × Angus and Limousin × Angus crosses. The possible cause of tenderness differences amongst the cross-breeds is discussed.
Soil erosion in north Norfolk
Authors: Evans R. , Nortcliff S. 
Published: March 2009

SUMMARYSoil erosion in a field in north Norfolk is described. Gullies formed, one up to 2 m deep, 5 m wide and 214 m long, and from this gully about 450 t of soil was eroded. Other gullies and rills deposited about 275 t of soil. In the large (61 ha) field the area subject to erosion was small, about 2·5%. The soil, slope, cultural and rainfall factors which caused erosion are discussed. Erosion in this field is not a rare phenomenon and crop yields will be affected if erosion continues. A solution to the problem is suggested.
Nutritive value and the genetic relationships of cellulose content and leaf tensile strength in Lolium
Authors: Wilson D. 
Published: March 2009

1. The leaf tensile strength of individual plants of a population of Lolium (multiflorum x perenne) perenne was measured on four occasions, October and December 1963 (160 plants) and January and March 1964 (73 of the 160 plants). All plants had been chosen for the good uniform vegetative growth they had exhibited over several seasons. The cellulose content of the 14 weakest and 14 strongest plants in October and of all 73 plants in March was determined.2. There was a wide range in leaf strength, maintained from October to March, within the population. In October all 14 weakest plants had lower cellulose content than the 14 strongest and from these two groups six plants of low leaf strength and low cellulose content and six of high leaf strength and high cellulose content were selected as parent plants for divergent selections. In March there was a positive highly significant (P < 0.001) phenotypic correlation between leaf strength and cellulose content (r = +0.58).3. Two diallel crosses were performed, one within the six parents of low leaf strength and low cellulose content and the other within the six high parents. Leaf strength and cellulose data was obtained from progeny and from parental ramets in October 1964 and high overall heritabilities for both characters (approx. 0.8) calculated from achieved advances and parent/progeny regressions. Selection for high leaf strength and high cellulose content was more effective than for low.
The growth and development of a crop of bulrush millet (Pennisetum typhoides S. & H.)
Authors: Begg J. E. 
Published: March 2009

The growth and development of a crop of Bulrush millet (Pennisetum typhoides S. & H.) was evaluated by a series of ‘first’ harvests at weekly intervals during the growing season. A final harvest was taken at the end of the season to measure the regrowth.Tillers emerged from the second, until the 5th week after emergence where full light interception was recorded. Then a marked increase in dry-matter production, internode elongation and leaf area index occurred and a peak growth rate of 44 ± 4 g. of dry matter per square metre per day was recorded during the 9th week. General flowering occurred during the 13th week and at 16 weeks the crop yielded 21,735 kg. of dry matter per hectare.Regrowth yields were high following defoliations made at an early vegetative stage when the apical meristem was below the cutting height and then declined as internode elongation raised increasing numbers of apices above the cutting height. Extensive areas of the stand died when defoliated as it approached its period of maximum growth rate.
Studies of the skeleton of the sheep V. Radiographic and chemical investigations of the skeleton of Scottish Blackface ewes and wethers on three hill farms in Scotland
Authors: Benzie D. , Cresswell E. , Duckworth J. , Hill R. , Boyne A. W. 
Published: March 2009

1. Studies on the mineralization of the skeletons Scottish Blackface wethers and breeding ewes have been carried out on three widely scattered and differing Scottish hill farms using field radiography and bone-ash analysis.2. Regular small autumnal improvements in the density of the ewes' skeletons were detected by in vivo radiography using the right radii although, in general, the radii of the ewes were at all times considered to be in good condition (for Scottish Blackface sheep on the hill) and underwent no marked resorption (as judged from in vivo radiographs) during pregnancy and lactation. This was contrary to what was expected in view of the results of previously reported laboratory experiments (Benzie et al. 1955, 1956, 1959) and also in view of commonly held beliefs that hill pastures are, in general, deficient in calcium or phosphorus, or both of these dietary factors.3. There were few significant flock differences (both ewes and wethers) for the values assigned to the radiographs or for the results of skeletal ash determinations even though the flocks were maintained in widely separated and differing locations and husbandry systems.4. It is suggested that further field work along these lines may be of great value to the obtaining of a clearer understanding of the ewe: hill pasture relationship.
The osmotic pressure and the concentration of some solutes of the intestinal contents and the faeces of the cow, in relation to the absorption of the minerals
Authors: van Weerden E. J. 
Published: March 2009

In the cows' intestine there is no isotony with the blood serum. In the upper part of the small intestine the chyme is strongly hypertonic but as it passes along the intestinal tract to the large intestine it becomes more and more hypotonic. The hypertony in the small intestine is not due to inorganic elements but is caused by organic non-electrolytes.In the large intestine hypotony is the result of strong selective absorption of sodium against a concentration gradient.This is an important aspect of the sodium metabolism of the cow. Chlorine is also absorbed from the large intestine against a concentration gradient.
Population dynamics in fourteen lowland breeds of sheep in Great Britain
Authors: Wiener Gerald 
Published: March 2009

The flock books of fourteen Lowland breeds of sheep were examined to study flock size, flock age, the number and source of rams used, the extent to which flocks differ in genetic importance within their breeds, the effect of geographical location on flock attributes, and changes in breed organization over a period of time.All breeds taken together showed that 46% of the 2649 flocks involved had less than fifty breeding ewes and 15% had more than 200. 43% of flocks were less than 5 years old and 18% were over twenty. A third of all flocks used only one ram and 9% used five or more. All breeds were found to be arranged in a hierarchy such that only a small number of flocks in each breed supplied the majority of the rams and in particular the rams used by rambreeding flocks. The ‘top’ flocks were among the largest and oldest in each breed. Flocks in the ‘native’ region of each breed we e generally larger and older than those elsewhere, but for other flock attributes the differences between regions were more peculiar to breeds. The general pattern of breed organization appeared to apply at widely differing periods of time.
The influence of turning on the hatchability of hens' eggs I. The effect of rate of turning on hatchability
Authors: Robertson I. S. 
Published: March 2009

Eggs were incubated at various frequencies of turning (tilting through 90°) and their hatchability compared with eggs incubated as controls at 24 turns per day evenly distributed throughout the 24 hr. The turning treatments were: 0, once in 2 days, 2, 6, 12, 48, 96, 144, 192 and 480 turns per day.Differences in hatch of fertile eggs between the treated and control eggs at each level of turning were obtained and used to indicate the trend of hatchability in response to varying turning frequency and also the optimum rate of turning. This was observed to be 96 turns per day. Nil or few turns per day gave very poor results and at very high frequencies (up to 480x) hatchability decreased only slightly relative to the turning frequency.
Studies on calcium and magnesium in the alimentary tract of sheep I. The distribution of calcium and magnesium in the contents taken from various parts of the alimentary tract
Authors: Storry J. E. 
Published: March 2009

1. The distribution of calcium and magnesium in the contents of the reticulo-rumen sac, omasum, abomasum, small intestine, caecum and colon of the sheep was studied by means of ultrafiltration through collodion membranes.2. In all organs except the abomasum considerable proportions of calcium and magnesium existed in a non-ultrafilterable form. In the abomasum where the pH is normally between 2 and 3 there was virtually no bound calcium or magnesium. The proportion of ultrafilterable calcium in the small intestine appeared to be dependent on the pH of the digesta, low pH values favouring higher proportions of ultrafilterable calcium. With magnesium this correlation was less obvious and appeared to be upset by unknown factors in the animals consuming a fresh grass diet.3. From calculations it is postulated that the concentrations of ultrafilterable calcium and magnesium in rumen fluid are insufficient for these elements to be absorbed as freely diffusing ions, whereas in the abomasum and duodenum the concentrations of ultrafilterable calcium and magnesium are in favour of a net uptake from the gut.
Use of carcass measurements to predict total edible meat in Mexican commercial cattle
Authors: Butterworth M. H. , Díaz J. A. , L.  , Hoystad E. 
Published: March 2009

SUMMARYCarcass measurements have been used by various authors to predict total edible meat content of carcasses.Measurements were made on 180 commercial quality cattle of different phenotypes and sexes in a commercial slaughterhouse in Monterrey, N.L. Measurements were carcass weight, length, forequarter depth, side circumference, length of leg, length of forearm, leg shape, area of m.l.d. and total dissected meat. Multiple regressions were computed for both linear and allometric equations using a CDC 3300 computer.It was found that in both forms of the equation carcass weight accounted for the majority of the total variance (97·0% and 96·8% for the linear and the allometric forms respectively). Various measurements of forequarter depth improved the goodness of fit only slightly as did circumference of side and length of forearm.