bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiation absorption, growth and yield of cereals
Authors: Gallagher J. N. , Biscoe P. V. 
Published: March 2009

SummaryAnalysis of measurements of absorbed radiation and leaf area indices of wheat and barley crops showed that throughout most of growth the fraction of absorbed solar radiation could be described by a simple exponential equation.For several of these crops grown under a wide range of weather and husbandry at Sutton Bonington and Rothamsted, 2-weekly values of crop growth rate (C) were closely related to radiation absorbed until ear emergence and about 3·0 g of dry matter (D.M.) were produced by each MJ of photosynthetically active radiation (PAR) absorbed. Final crop weight was closelyrelated to total PAR absorbed during growth (SA); on average about 2·2 g D.M. were produced per MJ absorbed, equivalent to a growth efficiency (Eg) of approximately 3·9%. Unfertilized and drought-stressed crops had a smallerEg.The fraction of total crop D.M. harvested as grain (harvest index) varied more for wheat than for barley. Calculations of a maximum realizable grain yield made using the largest values ofEgandSAfor the crops measured and assuming a harvestindex of 0.53 (achieved in an experimental crop) showed a grain D.M. yield of 10·3 t D.M./ha to be possible. To achieve such a yield would require full crop cover from the beginning of April until the end of July in a typical English growing season.
The effect of protected lipids on nutrient intakes, blood and rumen metabolites and milk secretion in dairy cows during early lactation
Authors: Bines J. A. , Brumby P. E. , Storry J. E. , Fulford Rosemary J. , Braithwaite G. D. 
Published: March 2009

Summarysupplements of protected soya-bean–tallow were incorporated at 0, 1·7, 3·0 or 5·0 kg/day into a hay–concentrate diet and fedad libitumto Friesian cows during the first 13 weeks of lactation.Intakes of supplement during weeks 1–6 were 0,1·34, 2·25 and 3·18 kg/day and during weeks 7–13, 0, 1·64, 3·10 and 4·24 kg/day on each of the respective treatments.As the lipid supplement increased there was a reduced intake of hay and concentrates, giving rise to reduced intakes of total, protein, and particularly ‘carbohydrate’ (non-protein, non-fatty-acid) energy. Apparent digestibilities, particularly of fibre, decreased as fatty-acid intake increased. After correcting for endogenous losses, true digestibilities of organic matter, carbohydrate, protein, non-fatty-acid lipid, total energy, calcium, magnesium and phosphorus were unaffected by the amount of supplement given, whereas fibre digestibility was reduced by increasing the supplement. Fatty acid digestibility was little affected up to an intake of 1·4 kg/day but above this there was a sharp reduction.Yields of milk, milk energy, protein, fat and lactose were increased at low lipid supplementation but reduced at the highest supplementation when amounts of protein and carbohydrate digested were lowest.Lipid supplementation reduced concentrations of rumen total volatile fatty acids in association with reduced, proportions of butyrate and. increased proportions of propionat. Plasma β-hydroxybutyrate and magnesium were reduced and plasma free fatty acids increased in cows given lipid supplemented diets.There were no differences between treatments in plasma glucose, lactate or calcium nor in live-weight changes.
Studies on the nutritive value of silage with particular reference to the effects of energy and nitrogen supplementation in growing heifers
Authors: Griffiths T. W. , Spillane T. A. , Bath I. H. 
Published: March 2009

SummaryFour digestibility and balance experiments were carried out in which 33 growing heifers were fed basal diets of low dry matter silage offeredad libitum, supplemented with various levels of barley and/or groundnut meal or urea.Voluntary intake of the silages was low although apparent digestibility of D.M. was high (66–75%). There was a significant linear negative relationship between the intake of D.M. as supplement and silage D.M. intake.Apparent digestibility of crude fibre in the silages was high (74–83%). It was depressed significantly by addition of barley but not by addition of groundnut. There was a highly significant linear relationship between the digestibility of D.M. and G.B. in the mixed silage concentrate diets used.Metabolizable energy (M.E.) values for the silages varied from 2·04 to 2·52 Mcal/kg (8·5–10·5 MJ/kg) D.M. Supplementation with barley at approximately 1% of live weight, increased M.E. values of the mixed diets to 2·57–2·85 Mcal/kg (10·8–11·9 MJ/kg) D.M. Additional N had little effect on these values.Nitrogen retention was significantly increased in all experiments by barley supplementation. It was further significantly increased by groundnut in three experiments and by urea in one experiment.Multiple regression analysis showed that N retention was significantly related to both M.E. intake and intake of absorbed N, and to M.E. intake and intake of supplementary N.Apparent availabilities of Ca and Mg in silage based diets were low and the availability of Na varied with Na intake. Supplementation with either energy or nitrogen increased apparent availability and retention of Mg but did not exert consistent effects on availability or retention of Ca or Na.There was a highly significant linear relationship between ingested and digested Na but not for Ca or Mg. There was a highly significant linear relationship between absorbed and retained Ca and Mg, but not for Na.Animals fed second cut silages had rather low blood glucose levels and higher than normal levels of blood ketones.
Intra-varietal variability and response to single plant selection inGossypium hirsutumL.: II. Genotypic variability
Authors: Thomson N. J. 
Published: March 2009

SummaryProgenies of randomly chosen plants from spaced plant populations of four American and one African variety ofGossypium hirsutumL. were grown in replicated single-plant plots at Kimberley Research Station in 1967–68 (all varieties) and 1968–9 (two varieties only) to estimate intra-varietal parameters of genetic variability.Estimates of broad-sense heritability were usually similar when derived from components of variance on either a one- or two-season analysis basis or by parentprogeny regression Heritabilities were in general lowest for lint yield and boll number and highest for lint percentage. Mean value of heritability for lint yield and boll number, considered consistent enough on a varietal and seasonal basis to allow averaging, was about 0·15. Components of variance estimates of heritability on a single environment basis for other attributes ranged as follows: boll weight from 0·05 to 0·56, lint percentage from 0·29 to 0·80, mature height from 0·00 to 0·51, micronaire value from 0·20 to 0·63 and Pressley strength index from 0·05 to 0·56.Genetic coefficients of variation showed an opposite trend to that for heritability: lint yield and boll-number values were large and lint percentage, micronaire value, and Pressley strength indices small. Expected responses to selection for the top 2·5 % of the population for lint yield and boll number at around 10% were usually higher than for other attributes.Genotypic and phenotypic correlations were mostly similar but correlations often deviated widely between varieties. Positive lint yield correlations with micronaire value and negative lint yield correlations with Pressley strength index were recorded; these are often undesirable associations for breeding.The association between the period of maintenance under Ord conditions and variability shown phenotypically in the original populations was not evident from the quantitative inheritance studies. Residual variability following breeding was considered as accounting for the larger portion of the genetic variability.
Studies of the composition of sainfoin
Authors: Baker C. J. L. , Heimberg M. , Alderman G. , Eden A. 
Published: March 2009

1. Studies were made of the composition of Giant sainfoin cut successively at different stages of growth in two seasons under contrasting conditions of weather and soil.2. Cuts were taken at preflowering, early- and full-flowering stages of growth. Yields of both fresh material and dry matter substantiated the usual farming practice of taking two cuts at full flower in one season, and indicate that cutting sainfoin before it comes into bloom has a seriously depressing effect on productivity.3. Like most green fodder crops, sainfoin has a lower content of crude protein and nitrogen-free extractives, and a higher content of crude fibre as the plant increases in maturity. The mineral content is somewhat variable, and in particular the potassium content appears to reflect the status of this element in the soil.4. The ratio of leaf dry matter to total dry matter of the plant decreases with advancing maturity. The leaf composition is fairly constant, irrespective of stage of growth, number of cuts and season, the fibre content being remarkably constant in contrast with that of stem, where it increases with advancing maturity. Leaf is richer than stem in crude protein, ether extract and total mineral matter, particularly calcium. Thus changes which do occur in the composition of the plant are due to variations in stem composition and leaf-stem ratio.5. Analyses of sainfoin hay, made under both experimental and commercial conditions, are discussed, and the range of variation in the main constituents of thirty-five commercial samples is commented upon.6. The present investigations into the composition of sainfoin, both as green fodder and as hay, show figures that differ appreciably from those derived from earlier German work. Examination of the data available for the nutritive value of fresh and conserved sainfoin reveal anomalies which suggest that such data are not typical of the crop as grown in this country, and also suggest the need for more modern data.
Report on an experiment to compare the fattening values, for beef cattle, of silages made from grass cut at different stages of growth
Authors: Dodsworth T. L. , Campbell W. H. McK. 
Published: March 2009

1. The method adopted for making three different grades of silage, from grass cut at different stages of maturity, is described.2. A feeding trial is described including four groups of cattle fed on grades I–III silages and on swedes and straw respectively.3. The live-weight gains made are recorded together with the rate of dry-matter intake.4. A digestibility trial was carried out on the three grades of silage. The digestibility coefficients found are recorded.5. It is shown that cattle fed solely on silage build up a bigger ‘gut fill’, to the extent of 40 lb. (± 11), than similar cattle fed on swedes and straw.6. When an allowance had been made for a 40 lb. greater ‘gut fill’ in silage-fed cattle it was found that grades I and II silages produced a significantly greater rate of fattening than grade III silage and than swedes and straw.7. It was found that the rate of total daily drymatter intake rose to a peak at the eighth week and then fell; it did not continue to rise beyond that point but the cattle continued to gain in live weight.8. The efficiency of utilization of the dry matter of the rations fed increased during the latter part of the trial.9. It is suggested that the increase in efficiency of utilization of the dry matter consumed may be attributed to an adaptation in the rumen microflora of the cattle which proceeded for up to 8 weeks after the cattle were put on to the experimental diets.
The partition of phosphorus and aneurin in relation to phosphatase in the colostrum and milk of the cow
Authors: Chanda R. , Owen E. C. 
Published: March 2009

The partitions of phosphorus and aneurin were determined in the colostrum and in the transitional and mature milk of Ayrshire cows with the following results:1. The ratio of nitrogen to phosphorus was 11:1 in the first mammary secretion but dropped to a minimum value of 4·5:1 a week later. Thereafter the ratio increased throughout lactation attaining a value of 7·2:1 at the fortieth week. The first colostrum was very rich in both phosphorus and nitrogen.2. Phosphatase titre in colostrum was 154 units in the first post-partum secretion but decreased to 10 during the first five days of lactation. The titre fluctuated slightly during the next few days and increased gradually thereafter, attaining 189 units in the 38th week of lactation.3. Phosphatase was correlated positively with inorganic-P (r= +0·83) and negatively with both ester-P (r= −0·94) and lipid-P (r= −0·70), all P fractions being expressed as percentages of total P. The percentage of phosphorus present as casein was initially 19–21%, but was only 14% in late lactation.4. The first colostrum contained 74 μg. aneurin/100 ml. skim milk. This value became 35 in midlactation and only 28 in late lactation. The corresponding figures for cocarboxylase were 20, 5·7 and 2·3 μg./100 ml. respectively, and for protein-bound aneurin 14, 3·2 and 1·7 respectively. Both cocarboxylase and protein-bound aneurin were negatively correlated with phosphatase.
The potassium status of barley in relation to yields of grain
Authors: Nicholas D. J. D. 
Published: March 2009

1. Various portions of barley plants were made available for chemical tests from manurial experiments which were designed to test the effects of K treatment (broadcast and placed with the seed) on grain yield.2. The experiments were located at three centres differing in soil characters and K status. Centre A was severely deficient in K; centre B was moderately deficient and at centre C, K was adequate.3. A comparison was made between the results of the following tissue test methods for K, Mg, Ca, P and Mn: (a) diffusion method, using young leaf, mid-stem leaf, and internode respectively; (b) Waring blendor, and (c) ash analysis. Mn was not determined by the blendor method.4. The coefficients of variation for the quick tests compared favourably with those of ash analysis for K, Mg, Ca, P and Mn respectively. Variations in results in tissue tests for Ca were, however, significantly greater than those of ash analysis, at centre A (second sampling).5. Correlation coefficients between results of ash analysis and the tissue test methods for K, Mg, Ca, P and Mn were positive and significant for totals, treatment and treatment × sites, except for Mn in young leaf by diffusion method. The error term for P was also significant for the quick methods, thus decreasing the value of the correlations for this nutrient.6. Correlation coefficients of yields with ash analyses, Waring blendor and diffusion method (mid-stem leaf) analyses respectively were significant and positive for K and negative for Mg, Ca, P and Mn. This confirms an interaction of K with the other nutrients.7. Minimum K levels, determined 5 weeks after seeding, above which no further increase in yields may be expected at the three centres, were: by diffusion method, using young leaf, mid-stem leaf and internode, 700, 500 and 600 μg. extracted per. g fresh weight respectively; by Waring blendor using ‘tops’, 2000 μg. extracted per g. fresh weight; by ash analysis of tops 1·5% K in dry matter. There is evidence that these critical levels fall later in the season, especially in mid-stem leaves, presumably through translocation of K to the ears.8. Minimum levels of K required for optimum yields are above those associated with the onset of deficiency symptoms of the element. Thus chemical methods only can determine suboptimal levels of nutrients in relation to final yields.
A uniformity trial on groundnuts
Authors: Hodnett G. E. 
Published: March 2009

A uniformity trial on groundnuts has been analysed and the results discussed. Plant number is less variable than yield and less sensitive to shape of plot and of block. For yield, long narrow plots are more efficient than shorter and wider plots, in all shapes and sizes of blocks and in Latin squares. The plots should not be arranged end to end along the contours, but side by side, either singly or in pairs, forming compact blocks.The regression of the plot variance of the mean yield per unit area on size of plot approximately follows a linear logarithmic relationship. A similar relationship holds for plant number. The value of the regression coefficient b′ is low and it has been shown that, as expected, there is considerable gain from the use of small blocks. The efficiencies of various confounded and incomplete block designs relative to designs in larger blocks have been determined for some particular layouts, and values for other layouts, ignoring shape of plots and of blocks, have been obtained by interpolation.The field used for this uniformity trial appears equally variable in all directions.
The availability of calcium in three herbs of grassland
Authors: Armstrong R. H. , Thomas Brynmor , Horner K. 
Published: March 2009

1. The availability of the calcium in three common herbs, viz. narrow-leaved plantain, chicory and burnet, has been investigated using the rat as the experimental animal.2. Parallel methods used for the determination of calcium balance involved (a) the analysis of feed, faeces and urine, and (b) carcass analysis.3. The availability of the calcium, while high in all three species, was in the order plantain, chicory and burnet. All differences between means were significant atP= 0·05.4. There was shown to be some evidence of inverse relationships between fibre content and calcium availability, and between oxalic acid content and calcium availability.
The effect of under-feeding on the genital functions of a bull
Authors: Mann T. , Walton A. 
Published: March 2009

1. A study was made of the effect of underfeeding on the genital functions in the bull. Regular weekly collections of semen were made during (1) a 5-week pre-experimental period of normal feeding, (2) a 23-week experimental period of under-feeding, and (3) a 25-week post-experimental period of recovery.2. Although the food intake was reduced to such an extent that the bull began to lose weight at a rate of 6·5 kg. (1 stone) per week, the volume and density of semen and the motility and morphology of the spermatozoa were not significantly changed.3. In contrast to the testes, the secretory function of the male accessory glands was markedly affected by under-feeding. The concentration of fructose and citric acid in semen decreased to about 30 and 60% respectively of the original levels. During the recovery period the values for fructose and citric acid gradually returned to normal.
Chemical fat in the musculature of the sheep carcass
Authors: Pryor W. J. , Warren G. H. 
Published: March 2009

SummaryForty merino sheep of mixed ages including lambs, ewes, wethers and rams were slaughtered and dissected. The chemical fat content often muscle groups in each sheep was measured directly and the mean value for the musculature of the whole carcass calculated.A characteristic pattern of chemical fat deposition was shown with the intercostal muscle group and the abdominal group being consistently highest in fat content, the shin and hind-limb muscles lowest and other intermediate. The pattern of growth of intramviscular fat was consistent with differences in activity of the muscle groups in the maintenance of posture. It was postulated that variations in fat content in muscle groups are affected by differences in blood flow.A highly significant relationship was established between dry matter and chemical fat content for each of the muscle groups. The regression was characteristic for each muscle group, and differed for most groups.Regressions between individual muscle group fat and that of total musculature fat revealed that no group was consistently the best predictor of the total carcass musculature fat though there was considerable difference between the groups. It was concluded there is no group which could be used for prediction purposes commercially.In a group of 14 other ewes subjected to weight loss up to 30%, and half of which were implanted with resorcylic acid lactone, no discernible effects on muscle group fat content were revealed.
Oestrous cycle synchronization in Zebu cattle and its use in cattle production and management in the tropics
Authors: Jöchle W. , Hidalgo M. A. , Giménez T. , R. Garcia C.  
Published: March 2009

SummaryBetween March and August 1968 to 1970, Chlormadinone acetate (CAP), 10 mg/head/ day, was administered to 668 Zebu cows and heifers for oestrous cycle synchronization for 14, 12, or 9 days, the latter schedule supported by an injection of 5 mg estradiol valerate on day 2 to achieve luteolysis. Applied orally over a period of 14 days, CAP provided a reliable method for cycle synchronization. The severe anoestrous rate experienced in all herds reduced the overall percentage of synchronized animals. Fertility from insemination during the first synchronization period (day 2 to 10 after treatment) was slightly, yet insignificantly reduced, but was completely restored during the second synchronization period (day 20–30). Insemination only during this second synchronization period resulted in conception and pregnancy rates similar to those combined from the first and second synchronization period.Of factors tested for influencing synchronization and fertility, presence or absence of penis-deviated teaser bulls (psycho-stimulation) had no effect on the percentage of animals synchronized, or on post-treatment fertility. In well-managed herds, the percentage of animals responding to treatment was predetermined by the number of animals already cycling, reflecting their phase of reproductive life. Levels of management had an important impact on the success of cycle synchronization combined with artificial insemination. Both methods are managerial tools for improvement of already good management. Their failure under insufficient management conditions has diagnostic value.Possibilities and limits shown for oestrous cycle synchronization in Zebu cattle were similar to those reported in European cattle. Within these limits, CAP can be employed successfully as a means for cycle synchronization, providing sufficient synchronization and acceptable fertility and allowing economical use of artificial insemination.