bluuebunny/crossref_metadata_2025_split huggingface dataset:
The utilization of the dietary energy of pangola and setaria by young growing beef cattle
Authors: Tudor G. D. , Minson D. J. 
Published: March 2009

SUMMARYThe net energy values for growth and fattening of two artificially dried tropical grasses-, pangola (Digitaria decumbens) and setaria (S. sphacelata var. sericea cv. Nandi), of similar estimated metabolizable energy content (8·07 and 7·96 MJ/kg D.M.) were determined with cattle using a slaughter technique. Growing cattle with a mean initial weight of 175 kg were given equal quantities of dry matter of the two grasses at each of three planes of nutrition above maintenance for a period of 152 days.The initial energy, fat and protein content of the total body of the 24 test animals was estimated from regressions relating fasted live weight to theśe components, derived from 12 similar cattle slaughtered at the beginning of the feeding period. The final energy, fat and protein content of the test animals was determined directly by chemical analysis. The metabolizable energy (ME) content of the grasses was estimated from the level of digestible energy (DE) determined with eight cattle, assuming that ME = 0·815 DE.The cattle fed pangola gained more live weight, empty-body weight, fat, protein and energy than animals fed similar quantities of setaria. The net energy value for growth and fattening (NEf) was determined using regressions relating energy retention to the quantity of dry matter eaten. NEf in MJ/kg dry matter was 2·27 for pangola and 1·31 for setaria.Efficiency of utilization of ME for growth and fattening (kf) was.27·7% for pangola and 16·9% for setaria. These values for tropical grasses are lower than any values reported for temperate pasture species. Thus the lower efficiency of utilization of ME may cause the lower production of cattle which graze tropical grasses.It was concluded that as the kf values of different tropical grasses are not constant, kf values should be measured on a wider range of tropical grasses so that this factor can be taken into account when evaluating grasses in animal production systems.
On the analysis of replacement series diallel experiments
Authors: Sinclair D. F. , Gleeson A. C. 
Published: March 2009

SummaryThe analysis of plant competition experiments in which all possible pairs ofpgenotypes are grown in replacement series is discussed. Two methods of analyses, using models of de Wit (1960) and Gleeson & McGilchrist (1980), are compared. The two approaches, which are shown to be linked algebraically, complement each other in terms of agronomic interpretation.
The estimation of energy expenditure from heart rate measurements in working oxen and buffalo
Authors: Richards J. I. , Lawrence P. R. 
Published: March 2009

SummaryThe heart rates and corresponding energy expenditure of adult Brahman cattle (Bos indicus) and water buffalo (Bubalus bubalis) were measured whilst they were standing, walking at speeds of up to 1 m/sec and pulling loads of up to 50 kg for periods of 1–2 h/day. Correlations of heart rate with energy expenditure showed a positive linear relationship within species although a distinct difference was exhibited between species. However, when heart rate and energy expenditure were expressed relative to their respective resting values (RHR and REE respectively), the results for all animals fitted the same line:REE = 2·251 RHR – 0·954 (r = 0·93; n = 49).More importantly, the relative heart rate and actual energy expenditure per unit metabolic body weight (EEW) for all animals fitted a common line:EEW = 24·94 RHR – 16·25 (r = 0·91; n = 49),where EEW is in watts/kg0·75 and RHR = heart rate of the working animal/heart rate at rest. This assessment of the energy expenditure from measurement of heart rate and live weight thus allows a prediction to be made of the energy requirements of working draught cattle under field conditions.
Studies on growth and symbiotic nitrogen fixation of Rhizobium of Vigna radiata under stress conditions
Authors: Rai R. , Prasad V. 
Published: March 2009

SummaryOne fast-growing acid-producing Rhizobium strain 995 of Vigna radiata was screened for growth behaviour in acid, saline and alkaline media. It grew well in yeast-extract mannitol broth of wide pH range as well as varying concentrations of NaCl, Na2SO4 and MnCl2. Variation in nodulation and N2-fixation efficiency occurred on different varieties of green gram, while strain characteristics were not affected by soil stress.
Factors causing small curds in cauliflower crops
Authors: Crisp P. 
Published: March 2009

SummaryVigorous cauliflower plants sometimes bear abnormally small curds, yet this common problem has received little recognition or attention from research workers. Curd size is often reduced towards the end of the harvesting period of a crop, and this is more marked if environmental conditions reduce mean curd size and lengthen the time to maturity. Small late curds may be a consequence of their slow growth rather than their late initiation. Cultivars differ in their tendency to produce plants with late maturity and small curds. This may not be due to genetic differences within cultivars. Moreover, breeding to eliminate or reduce this condition may not be possible without affecting overall maturity time and curd size.
Inoculation of white clover with different strains of Rhizobium trifolii on a mineral hill soil
Authors: Mytton L. R. , Hughes D. M. 
Published: March 2009

SummaryS.184 white clover was established on an unimproved brown earth hill pasture using both surface seeding techniques and conventional cultivation. Inoculation with selected Rhizobium trifolii improved clover dry-matter production by 0·017 t/ha on the cultivated trial in the establishment year and by 0·13 t/ha in the first harvest year. On the uncultivated site, clover dry-matter production was increased 1·88 t/ha by the best inoculation treatment in the first harvest year and 1·01 t/ha in the second harvest year. Rhizobium strains differed in their ability to promote clover growth. Clover yields were substantially better on the uncultivated than on the cultivated trial. The implications of the results for hill land pasture improvement are discussed.
The design and conduct of experiments to measure animal and herbage production responses to fertilizer nitrogen under cutting and grazing managements
Authors: Large R. V. , Cobby J. M. , Baker R. D. 
Published: March 2009

SummaryTwo experiments were conducted to provide information on the precision of herbage sampling, the degree of replication and the logistics of managing rotational and continuous grazing experiments. In a third experiment the possibility of estimating herbage growth, during the rotational grazing of paddocks for 4 days, by linear extrapolation of measured growth estimates made during the interval between grazings was investigated. A fourth experiment was then conducted to investigate animal and herbage production responses to nitrogen applied at five levels over the range 80–900 kg N/ha with three replicates per treatment.Results from Expts 1 and 2 showed that similar precision could be obtained under both rotational and continuous systems of grazing with the same number of replicates and samples of herbage. There was little advantage in having more than three replicates and four samples per paddock or two replicates and eight samples per paddock. Under continuous grazing a 3-weekly sampling and movement of exclosure cages was indicated. It was also found, from Expt 3 that, under rotational grazing, linear extrapolation of growth from 0–24 days did not reflect growth to 28 days in a consistent manner. Six animals per treatment, permanently in the paddocks, proved adequate for the estimation of live-weight gain.Experiment 4 confirmed that response curves could be fitted with an acceptable degree of precision if there was one low, one very high, and two intermediate levels of nitrogen. Adjustment of the number of animals to maintain sward height at between 5 and 7 cm ensured similar sward conditions and rates of live-weight gain across all treatments.The problems associated with the measurement of herbage production under grazing are discussed.
Growth patterns in sheep: changes in the chemical composition of the empty body and its constituent parts during weight loss and compensatory growth
Authors: Butler-Hogg B. W. 
Published: March 2009

SummaryChemical compositional (protein, fat, ash and water) changes in the fleece-free empty body, carcass, viscera and ‘remainder’ components of Corriedale wether sheep were measured by serial slaughter of animals following five different growth paths.The composition of sheep, after losing up to 34% of body weight over 18 weeks at 125 g/day, was significantly different from a continuously growing control group at the same body weight, but the actual differences in the weights of tissues were small. At the end of weight loss all treatment sheep contained more fat and protein, and less water than controls.The different growth paths followed during weight loss led to differences in the proportions of protein, fat, ash and water lost and to differences between the three body components in the relative contribution made by each.The periods of weight loss led to changes in the relative growth coefficients for chemical constituents during realimentation, particularly those of fat and ash which were reduced, and of water which was increased.The response to realimentation differed between body components, particularly the carcass and viscera. Above the body weight at which weight loss was imposed the realimented sheep did not differ in chemical composition from the continuously ad libitum fed controls when compared at the same weight.
Oestrous and ovarian activities of Finn-cross ewes during the post-partum and the seasonal anoestrous periods
Authors: Amir D. , Rosenberg Miriam , Schindler H. 
Published: March 2009

SummaryThe seasonal and post-partum oestrus occurrence and ovarian activity, assessed by the plasma progesterone concentrations, were studied in Finn-cross ewes following autumn and winter lambings.The last seasonal oestrous cycle was followed by a silent ovulation in C0% of the Finn × Awassi ewes. Silent ovulations during midanoestrus occurred in 50% of the ewes, and in 90% of the animals a silent ovulation preceded the normal resumption of the seasonal sexual activity.The first post-partum oestrus occurred within C0 days after October lambings in about 90% of the ewes. Silent ovulations before the first post-partum oestrus were evident in 70% of the recycling ewes.It is suggested that breeding ewes with ovarian activity after oestrus induction during anoestrous periods might increase the reproductive performance of the flock in a frequent lambing system.
Water use by winter wheat as affected by soil management
Authors: Goss M. J. , Howse K. R. , Vaughan-Williams Judith M. , Ward M. A. , Jenkins W. 
Published: March 2009

SummaryIn each of the years from September 1977 to July 1982 winter wheat was grown on one or more of three clay soil sites (clay content 35–55%) in Oxfordshire where the climate is close to the average for the area of England growing winter cereals.The effects on crop water use of different soil management practices, including ploughing, direct drilling and subsoil drainage, are compared. Cultivation treatment had little effect on the maximum depth of water extraction, which on average in these clay soils was 1·54 m below the soil surface. Maximum soil water deficit was also little affected by cultivation; the maximum recorded value was 186±7·6 mm. Subsoil drainage increased the maximum depth of water extraction by approximately 15 cm and the maximum soil water deficit by about 17 mm.Generally soil management had little effect on either total water use by the crop which was found to be close to the potential evaporation estimated by the method of Penman, or water use efficiency which for these crops was about 52 kg/ha par mm water used.Results are discussed in relation to limitations to potential yield.
Combining-ability analysis in cotton for agronomic characters, fruiting efficiency, photosynthesis and bollworm resistance
Authors: Bhardwaj H. L. , Weaver J. B. 
Published: March 2009

SummaryHeterosis and combining abilities for yield, bollworm resistance, fruiting efficiency and photosynthesis were studied in a five-parent diallel involving cotton (Gossypium hirsutum) strains differing in their resistance to the bollworm complex (Heliothis zea and H. virescens).Substantial magnitudes of useful heterosis (over the commercial cultivar ‘Coker 304’) were observed for yield and other agronomic characters. Useful heterosis for yield ranged from 1 to 32·7%. The highest yielding hybrid was Coker 304 × PD 695. The strain PD 695 is moderately resistant to bollworms.All the hybrids having at least one resistant strain as their parent suffered less damage from bollworms than Coker 304. The resistant strains (BW 76–31, PD 695 andred leaf cotton) had desirable general combining ability (GCA) effects for bollworm damage. Relative yield (yield without protection expressed as percentage of yield with protection) was used as a measure of bollworm resistance. The high gossypol strain BW 76–31 had desirable GCA effects for relative yield, bollworm damage to buds, number of live worms and for bolls per plant. The fruiting efficiencies and photosynthetic rates of some bollworm-resistant strains were similar to those of a high-yielding, moderately susceptible cultivar.Combining-ability analysis indicated BW 76–31 to be a desirable parent for use in hybridization programmes for improving agronomic performance, fruiting efficiency, photosynthetic rate and bollworm resistance. It was also observed that bollworm-resistant cottons do not always have lower fruiting efficiencies and photosynthetic rates and it might be possible to combine this resistance with high yields.
Time of Sowing and the Yield of Winter Barley
Authors: Green C. F. , Furmston D. T. , Ivins J. D. 
Published: March 2009

SummaryDuring three growing seasons (1980–3) the influence of sowing date (early September to mid-November) on the yield of winter barley (cv. Igri) was assessed. Delaying sowing resulted in a linear decrease in maximum grain yield at a rate of 0·43 % for every day sowing was delayed. Advancing the date of sowing increased the duration of preanthesis development, increased the level of tillering and hence ear density at harvest. Yield was linearly related to the resultant higher number of grains.
Vegetative growth of winter barley in relation to environmental conditions and grain yield
Authors: Ramos J. M. , del Moral L. F. Garcia , Recalde L. 
Published: March 2009

SummaryThe object of this study was to investigate the vegetative growth in six barley varieties grown in southern Spain (Granada) during 1979, 1980 and 1981. The results showed that crop dry weight (CDW) was dependent on environmental factors (mean temperature, rain, and radiation) which were the determinants of the two CDW components, leaf area index (LAI) and leaf area ratio (LAR). However, the effects of these climatic factors on crop growth rate (CGR) and on its components, mean leaf area index () and net assimilation rate (NAR), were partially obscured by ontogenetic drift. In addition, a highly significant relationship was demonstrated between CDW (when the LAI reaches its maximum value) and grain yield. This suggests that the pre-anthesis period has a great influence in the determination of grain yield variation in hot, dry areas, where photosynthesis is very limited after ear emergence.
Drought resistance of hard wheat cultivars measured by a rapid chlorophyll fluorescence test
Authors: Havaux M. , Lannoye R. 
Published: March 2009

SummaryDisks of hard wheat (Triticum durumDesf.) leaves subjected to rapid desiccation over 4 h showed noticeable changes in the shape of thein vivochlorophyll fluorescence induction curves. In drought-sensitive varieties (such as Claridoc), water stress resulted in a strong inhibition of the slow fluorescence induction transients. In particular, the fluorescence quenching rate was markedly decreased in water-stressed leaf disks. In contrast, leaves of drought-resistant varieties (such as Aouedj) showed only minor changes in chlorophyll fluorescence. The results of this investigation suggest that the slow transient of thein vivochlorophyll fluorescence induction phenomenon may provide a simple method for selecting drought-tolerant wheats.
The effect of rate of application of nitrogen fertilizer on soil copper uptake by barley under unirrigated conditions
Authors: Tiwari R. C. , Adinarayana J. 
Published: March 2009

SummaryField experiments were conducted on four barley cultivars (two hulled and two hullless) grown under unirrigated conditions in Varanasi, India, to observe the effect of rate of application of nitrogen on copper concentration and uptake in plants and soils. The copper concentration in both plants and soil decreased with age of crop because of the dilution effect of more vegetative growth. Varieties did not differ in copper concentration of plants but increasing application of nitrogen decreased copper concentration in the plants. Since the hulled varieties yielded more than the hull-less ones, they removed more copper from the soil. Similarly yield was increased linearly by the application of N fertilizer and this led to a linear increase in depletion of available copper.
The influence of sowing rate and row spacing on the plant density and yield of red beet
Authors: Benjamin L. R. , Sutherland R. A. , Senior D. 
Published: March 2009

SummaryThree experiments examined the effects of sowing rate and between-row spacing on the plant density and yield of red beet.The proportion of seeds which produced mature plants decreased when the mean distance to the nearest neighbour was less than 5 cm. In these experiments, this distance was governed by within-row spacing. Thus, plots with narrow-spaced rows achieved a higher plant density than those with wide-spaced rows, when sown with the same weight of seed.Total yield of beet per unit area decreased with increasing plant density. Maximum yields per unit area of small beet were achieved at high plant densities, whereas maximum yields of large beet were achieved at low plant densities. The effect of between-row spacing on yield was much smaller than that of density, and was important only for crops harvested early. Shoot yield per unit area was measured in two experiments and was not affected by row spacing in either. Shoot yield was not affected by plant density in one experiment, but, in the other, tended to a maximum value with increasing plant density.
Observations on the vitamin metabolism of the common fowl IV. Free and combined riboflavin in the magnum and liver of the laying hen fed a diet high in riboflavin
Authors: Bolton W. 
Published: March 2009

1. The partition of riboflavin into free vitamin, flavinmononucleotide and flavin-adenine-dinucleotide in the livers and magnums of laying hens fed a diet rich in riboflavin has been determined.2. Free riboflavin in the liver amounted to 4·3% of the total vitamin, and it is concluded that this tissue does not play any part in the day-to-day metabolism of riboflavin secretion in the albumen.3. The average amount of free riboflavin in the magnum is 45% of the total vitamin. As an egg passes through the organ, the amount decreases; this decrease is equal to the amount secreted in the albumen of the egg.4. It is suggested that riboflavin accumulates in the blood while an egg is in the magnum, and in the magnum in the intervals between the passage of eggs, and that the riboflavin in the albumen is secreted at the same time as the albumen.
The chemical composition of the pre-sperm fraction of bull ejaculate obtained by electrical stimulation
Authors: Lutwak-Mann C. , Rowson L. B. A. 
Published: March 2009

1. Semen was collected from bulls by means of the electro-ejaculation method developed by Thibaultet al.(1948).2. A copious sperm-free fraction of the ejaculate, produced in the early phase of stimulation, was examined for its chemical composition.3. This secretion was found to have a low protein content, but its chloride concentration was higher than in the sperm-containing fractions of the ejaculate. Fructose and citric acid occurred in very low concentrations, and 5-nucleotidase was absent in the pre-sperm secretion. This indicates clearly that the secretion does not originate either in the seminal vesicles or in the ampullar glands; it is probable that it represents a discharge from the urethral glands.4. The effect of the pre-sperm ejaculate fraction upon bull sperm fructolysis and motility was examined; both were unaffected by a considerable excess of this secretion.5. The chemical composition of the pre-sperm secretion makes it unlikely that under physiological conditions it could play a role in the nutrition of the spermatozoa; presumably, its chief function is the clearing of the urethral passage prior to the descent of the semen proper.
The liability of seed crops of perennial ryegrass (Lolium perenne) to contamination by wind-borne pollen
Authors: Griffiths D. J. 
Published: March 2009

Some aspects of intervarietal crossing in Lolium perenne have been studied.Using a number of experimental designs with non-red plants as the tester variety, results have been obtained as to the effects of isolation distance on intervarietal crossing.In all cases contamination decreases rapidly, at first with increasing distance, but there is a progressive reduction in the rate of decrease produced by repeated increases in isolation distance. The actual rate of decrease varies with the number and arrangement of plots.The effect of intravarietal pollen in reducing intervarietal crossing appears similar to that of distance in its mode of action. Within short distances from the contaminant, additional rows of intervening plants are highly effective in reducing contamination. This suggests that pollination within a population of plants occurs chiefly between neighbouring plants.The flowering periods of the different strains of Lolium perenne and L. italicum overlap to varying degrees. Several early strains flower at the same time, e.g. British commercial, New Zealand Certified Mother Seed and Station-bred S24 perennial rye-grass; others, such as Kentish indigenous perennial ryegrass and strains of L. italicum, which are intermediate in date of flowering, overlap with both the early- and late-flowering strains.Intervarietal crossing is considerably reduced when varieties which differ widely in date- of flowering are grown in close proximity to one another, but even in the case of extreme early and late strains some spatial isolation, or discarding of border rows, is necessary for maintaining varietal purity.In certain instances when seed crops of early-flowering strains are endangered by late-flowering plants growing in adjoining leys, satisfactory isolation may be achieved through cutting back the contaminant crop just before flowering. When seed crops of late-flowering strains are grown alongside leys containing early-contaminant varieties, cutting back should be delayed until a few days prior to commencement of flowering in the seed crop.The practical application of the results to grass seed production has been discussed. Existent isolation requirements appear not too great for grass seed crops intended for further seed multiplication, but for commercial seed crops the spatial isolation distance generally recommended may be reduced to 100, or even 50 yd., in the case of large fields.