bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stolon characteristics related to winter survival in white clover
Authors: Collins R. P. , Rhodes I. 
Published: March 2009

SUMMARYChanges in the stolon carbohydrate contents (water-soluble and total non-structural) of four white clover populations were measured at the beginning and end of winter. Three of the populations were of Swiss origin - two of these were from high-altitude pastures, and the other from a valley location. Grasslands Huia was measured as a control variety. Levels of both types of carbohydrate declined during the winter in all populations. The Swiss populations from high altitudes contained the highest levels of both carbohydrate types.An artificial freezing test was carried out on stolon segments collected from a range of clover populations (including the two high-altitude Swiss clovers) growing in field plots in January, and values of ‘lethal dose 50’ (LD50) were calculated. The two Swiss populations had the lowest LD50 values, indicating a greater intrinsic tolerance to freezing in those plants than in the other populations (of lowland temperate origin).One of the Swiss populations, Ac3785, was grown under two temperature regimes and short daylength to determine whether its tolerance to freezing increased with time. Significant increases in tolerance occurred after 8 days at 2 °C, but plants grown at 8 °C showed no change in tolerance even after 30 days.The results suggest that (i) stolon carbohydrate content is an important factor in the overwintering of white clover, (ii) there is a considerable amount of genetic variation in cold tolerance within white clover, (iii) artificial freezing tests can provide a method of predicting the survival of clover stolons during winter and (iv) the cold hardiness of white clover increases with time spent at temperatures near 0 °C under short daylengths.
Metabolic adaptation during lactation in winter-shorn sheep
Authors: Symonds M. E. , Bryant M. J. , Lomax M. A. 
Published: March 2009

SUMMARYThe effects of winter shearing, 8 weeks before lambing, on ewe and lamb live weight changes over the first 30 days of lactation were studied in Reading between February and March 1984. Differences in ewe body condition score (BCS) and plasma concentrations of glucose, nonesterified fatty acids (NEFA), 3-hydroxybutyrate, growth hormone (GH), insulin, cortisol and thyroxine between shorn and unshorn groups of ewes were measured over the same period.Lambs from shorn ewes grew, on average, 20% faster than those from unshorn controls even though both groups of lambs were of similar mean birth weight. There was no difference in maternal feed intake between shorn and unshorn groups, and ewe live weight and BCS decreased between the day of lambing and day 30 of lactation in all ewes. Plasma samples taken at hourly intervals for 24 h on days 12 and 27 of lactation demonstrated that shorn ewes had significantly lower plasma concentrations of insulin than unshorn controls; on day 27 of lactation, higher circulating concentrations of GH were recorded in the shorn group. There were no differences in the plasma concentrations of glucose, NEFA, cortisol or thyroxine between the two groups of ewes. It is concluded that metabolic adaptation by shorn ewes to the cold environment of a British winter during early lactation results in endocrine changes in ewes which are likely to increase the partition of nutrients towards milk production. This results in a higher lamb growth rate than in lambs reared by unshorn controls.
Persistence of tropical forage grasses in shaded environments
Authors: Wong C. C. , Stur W. W. 
Published: March 2009

SUMMARYThe sowing of improved tropical forages in tree plantations can increase animal productivity considerably, but planted grasses often fail to persist under grazing, resulting in unstable pastures. An experiment was conducted in Brisbane, Australia during the summer of 1989/90 to investigate whether the failure of tropical grasses to persist in shade when regularly defoliated is related to their growth habit. Two shade-tolerant grasses of contrasting growth habit (prostrate Paspalum wettsteiniiv. erect Paspalum malacophyllum)were grown in simulated swards at light levels of 100, 50 and 20% of full sunlight and defoliated every 2 or 4 weeks. Shading and frequent cutting reduced total dry matter yield equally in the two grasses. Shading also reduced tiller density. Paspalum wettsteinii persisted poorly under frequent (2-weekly) defoliation in shade. Plant survival rate of this grass was 66% in the 2-weekly defoliation-20% light transmission treatment, compared with 94% in P. malacophyllum. The poor survival of P. wettsteinii was related to its high allocation of total yield to roots, low tiller density and low total nonstructural carbohydrate yield in residual biomass after defoliation. The inability of P. wettsteinii to adjust in shade to frequent defoliation led to a continual decline in photosynthetic area and light interception, resulting in the depletion of energy reserves, increased susceptibility to Rhizoctonia fungal infection and ultimately to death. It was concluded that growth habit per se cannot be used as a simple indicator for selecting tropical grasses for shaded environments. Instead, morphophysiological adaptation to defoliation in shade was critical for plant persistence.
The dacron bag technique for comparing rumen degradability of untreated and ammonia-treated barley straw – effect of particle size and degree of replication
Authors: Pike D. J. , Owen E. , Said A. N. 
Published: March 2009

SUMMARYSix rumen-fistulated steers were studied over six periods of 3 days at Reading University's Animal Production Research Unit. In each period, eight dacron bags comprising two replicates of the 22 factorial treatment set consisting of untreated and NH3-treated barley straw in chopped (12–54 mm) or ground (2·5 mm screen) form were placed in the rumen of each steer. Bags were left in the rumen for a given time which was one of the set 6, 9, 15, 24, 48, 72 h. Percentage dry matter (DM) disappearance from dacron bags was consistently higher for NH3-treated than untreated straw and higher for ground than chopped straw. Analysis of variance gave F ratios for period and steer which were non-significant but of similar size, showing that using fewer animals could be compensated for by using more periods. Percentage DM disappearance as a function of time was well described by the model y = a — beet. The parameter defining rate of disappearance c, was similar for the four forms of straw. Differences between straws occurred in values of a (potential degradability) and b suggesting that physical form of material put into dacron bags needs standardizing if absolute values of a are to be used (e.g. for predicting roughage intake). Experimental designs need further research.
A simple model of pH in slurry
Authors: Sommer S. G. , Husted S. 
Published: March 2009

SUMMARYAmmonia volatilization from stored slurry or surface-applied slurry in the field is strongly affected by pH. Thus a simple, iterative model was developed to predict pH changes in slurry. Concentrations of NH4+/NH3, CO2/HCO3-/CO32-and volatile fatty acids were input data to the model. The model was validated by titrating 17 slurry samples collected from four cattle farms, seven pig farms and three biogas plants. Predictions of pH agreed well for 14 slurries with titration data in the pH interval from 4 to 10. Simulations indicated that microbial degradation of VFA to methane and carbon dioxide resulted in a pH increase if the carbon dioxide produced was lost to the atmosphere. There was little change in pH if the produced carbon dioxide dissolved in the slurry.
Diagnosis and correction of soil nutrient problems of common bean (Phaseolus vulgaris) in the Usambara Mountains of Tanzania
Authors: Smithson J. B. , Edje O. T. , Giller K. E. 
Published: March 2009

SUMMARYStages in the diagnosis of an interveinal leaf chlorosis in bean in the Usambara Mountains of northern Tanzania are described. Leaf tissue analysis, soil analysis, a 25 factorial trial with treatments of nitrogen, phosphorus, potassium, the trace elements copper and zinc and lime at one location and data from a series of 43 factorial trials of N, P and K demonstrated the leaf condition to be due to potassium deficiency. Large growth and yield responses to N, P and K were recorded. The responses were accompanied by greater numbers of pods and seeds/pod. The application of N and K increased leaf concentrations of the respective elements but depressed the concentrations of other major and minor elements in leaves. There were no effects of trace elements or lime.
Effect of concentration and blend of added fat in the diet on the performance of growing pigs
Authors: Patterson D. C. 
Published: March 2009

SUMMARYDiets with added fat at 25, 50 and 100 g/kg were formulated with four blends of beef tallow: soya oil, namely 100:0, 75:25, 50:50 and 0:100. An additional diet had no added fat (control diet) to give an experimental design of (3 × 4) + 1. A total of 96 individually penned pigs was used (mean initial and final live weights of 22·4 and 87·5 kg, respectively). The experiment was carried out during the period July 1985 to February 1986 at the Agricultural Research Institute, Hillsborough. Equal numbers of boar and gilt blocks were used and the pigs were fed individually to a scale to give equal amounts of digestible energy: live weight0·75 Neither concentration of fat nor blend of fat had any significant effect on the rates of live weight or carcass weight gain. Increasing concentration of fat significantly improved the carcass feed conversion ratio (P < 0·001), but the blend of fat had no significant effect. Neither killing-out yield nor the intake of digestible energy per unit of carcass gain was significantly affected by the concentration of added dietary fat nor the blend of fat. Fat treatments did not significantly affect the lean plus bone content of the ham joint, drip loss from or the depth of colour of the longissimus dorsi or the weight of flare fat. No evidence was found of synergistic effects between the fat and nonfat components of the diet nor between fats within the blends of fat on growth, digestible energy consumed per unit of carcass gain and carcass attributes. Boars had a more efficient conversion of feed to carcass gain than gilts (P < 0·01).
Effluent from grass silage for finishing pigs
Authors: Patterson D. C. , Kilpatrick D. J. 
Published: March 2009

SUMMARYA total of 52 individually penned pigs (mean initial and final live weights (LW) of 31·7 and 81·5 kg, respectively) was used in a randomized block experiment at the Agricultural Research Institute of Northern Ireland, Hillsborough, in 1984. The treatments were based on dietary regimes which comprised a control diet in which meal was offered at 86 g dry matter/k W0·75 per day or diets in which silage effluent was substituted for part of the allowance of meal of the control diet at 125, 175, 225 and 275 g/kg on a dry matter basis to give 0·125, 0·175, 0·225 and 0·275 effluent diets. There was also a negative control diet in which meal was offered at 850 g/kg of the rate of feeding of the control diet. Each of these dietary treatments included water available ad libitum. In a further treatment, effluent was substituted for 225 g/kg of the meal allowance of the control treatment on a dry matter basis, but additional water was not offered. The treatment based on the 0·275 effluent diet was omitted from the first four replicates.Some refusals of diet occurred at the higher rates of effluent feeding, with mean refusals of 7, 11 and 21 g/kg, respectively, for the 0·175, 0·225 and 0·275 effluent diets on a dry matter basis. Significant linear and quadratic contrasts (P <0·01) were found for daily LW gain, feed conversion ratio and total liquid intake. The quadratic response curves for daily LW gain and feed conversion ratio had relatively flat peaks, optimum values occurring at concentrations of effluent in the diet of 95 (S.E. 17) and 99 (S.E. 15) g/kg, respectively. From the response curves, performance in terms of LW gain and feed conversion ratio was equal, or superior, to that obtained with the control diet at concentrations of effluent of up to 190 (S.E. 33) and 199 (S.E. 30) g/kg, respectively, but deteriorated at higher concentrations of effluent.Additional water was consumed at all rates of inclusion of effluent. However, from the quadratic equations, the total consumption of liquid was lower with diets containing effluent at up to 161 g/kg of diet than with the control diet.
Control of manganese deficiency in field peas grown for seed or human consumption
Authors: Knott C. M. 
Published: March 2009

SUMMARYThe effect of foliar applications of different formulations of manganese on pea yield and ‘marsh spot’, a seed defect which reduces quality of peas (Pisum sativum) grown for human consumption or seed was evaluated in nine experiments in the East of England from 1992 to 1994. Sprays, at dose rates recommended by the manufacturer, were applied to field peas, cvs Maro or Bunting, on three occasions at the four node pea growth stage, first pod and 14 days later, or on two occasions at first pod stage and 14 days later. Although the sites selected had a previous history of marsh spot in pea crops, there were no visual foliar symptoms of manganese deficiency in peas grown in any year at any site. Applications of manganese did not increase yields compared with untreated peas and there was no effect on maturity. Marsh spot was negligible in untreated peas at sites where soils had the lowest levels of manganese (22 and 44 mg/kg), thus soil analysis for manganese may be inappropriate as a guide to prediction of marsh spot problems. The three spray programmes, which included an early application of manganese at the 4–5 node stage, gave no statistically significant improvements in marsh spot control. There was a good correlation between amounts of manganese applied and reductions in marsh spot, and manganese sulphate, 31% w/w at 3·1 kg/ha applied as a split dose, achieved the best control. An exception was the manganese carbonate 50% w/v formulation which may have been poorly assimilated by the plant. Chelated manganese as MnEDTA 6·4% w/v at the rates recommended by the manufacturer was inadequate for control of marsh spot in all years.
Dwarfism does not modify mean area per leaf and light interception in indeterminate autumn-sown white lupin
Authors: Harzic N. , Huyghe C. 
Published: March 2009

SUMMARYThe effect of dwarfism on leaf number and size was investigated on six pairs of tall and dwarf nearisogenic lines of indeterminate autumn-sown white lupins (Lupinus albusL.). Dwarfism reduced mainstem height by 41% and first-order branch length by 22%. It also slightly decreased the number of leaves on the mainstem and first-order branches without affecting the time of flowering. Leaf size was not reduced. Logistic equations were used to analyse differences in the patterns of light interception by leaf canopies relative to thermal time from sowing during the growth of seven dwarf lines and three tall cultivars sown on different dates. The genotypes studied had long periods of low light interception during their early growth. No differences were found between most of the equation parameters for dwarf and tall genotypes. Only the proportion of light intercepted at flowering differed and this was explained by differences in flowering time. The dwarf character did not limit the ability of the crop canopies to intercept light. It is concluded that the character can be introduced into a wide range of genetic backgrounds without deleterious effects.
The effect of the length and severity of feed restriction on weight, carcass measurements and body composition of goats
Authors: Mora O. , Shimada A. , Ruiz F. J. 
Published: March 2009

SUMMARYTwo experiments were done in Mexico (1992–93) to determine the response of goats to different periods of feed restriction on liveweight, organ weights and tissue composition. In each, the weight, body condition and daily dry matter intake (DM1) of two groups of 12 female, adult, non-lactating, non-pregnant, Nubian crossbred goats were recorded for 7 weeks (stabilization period; SP), to allow the animals to reach and maintain their liveweight and body condition. At the end of the SP the animals in Expt 1 (RP1) were feed restricted for 18 weeks and for 36 weeks in Expt 2 (RP2). Animals were divided into three groups receiving either 100 (FL1), 80 (FL2) or 60% (FL3) of the levels of DM1 previously observed. At the end of each experimental period all animals were slaughtered, carcass weights were recorded and viscerae were weighed.A sample of the soft tissues was chemically analysed. There were no significant changes in body condition in either experiment (P > 0·05). None of the feeding levels had an effect on carcass weight or the chemical composition of soft tissues (P > 0·05). Liver weights (as a proportion of slaughter weight) were significantly different among goats fed at different feeding levels in both experiments. The results of this study show the adaptation capacity of adult goats to medium and long term malnutrition, and the importance of the liver as a source for the generation of energy and for sustaining protein turnover. This could be especially important for goats grazing in arid and semiarid zones where dry periods can last for months and feed availability is therefore sometimes limited.
Efficacy of pest control strategies in Louisiana sugar cane: a preliminary survey
Authors: Ogunwolu E. O. , Reagan T. E. , Damann K. E. 
Published: March 2009

SummaryAlthough the first or second clonal cuttings of heat-treated sugar cane were widely used for seed, differences were not detected among crop years or locations in the incidence of ratoon stunting disease. Sugar-cane mosaic virus (SCMV) disease was widespread in all areas surveyed; however, the plant cane crop had a lower incidence of SCMV than the first or the second ratoon crop. The estimated cane yield was increased approximately 19·4 t/ha by heat treatment during the 2-year survey period.The management system used to control the sugar-cane borer (SCB), Diatraea saccharalis (F.), was effective regardless of the crop year or area surveyed. Season-long SCB control was achieved by the use of two (1981) or three (1982) properly timed applications of insecticide and the use of a SCB moderately resistant variety resulting in an average of 6–9% bored sugar-cane internodes.Poor weed management, particularly with johnsongrass (Sorghum halepense(L.) Pers.), accounted for much of the reduction in cane yield (P < 0·01); the estimated yields of the second ratoon crop were substantially altered, particularly those of farms surveyed in the Bayou Lafourche area.
The spread of the calibration set in near-infrared reflectance spectroscopy
Authors: Wetherill G. Z. , Murray I. 
Published: March 2009

SummaryFrequently in near-infrared reflectance spectroscopy, a calibration is developed using very restricted data sets, e.g. material from one season, a small area or of a limited type: consequently, the predictions may have limited validity. This paper describes the use of both restricted and wide calibration sets for the prediction of crude protein in grass, silage and hay. Results show that predictions from the wider calibration sets are often as good as or better than predictions from restricted calibration sets. Therefore the use of wide calibration sets should be considered much more frequently in near-infrared reflectance.
Pre-maturity gradients in shoot size and in number and size of florets for spring barley treated with mepiquat chloride
Authors: Waddington S. R. , Cartwright Phyllis 
Published: March 2009

SummaryEffects of mepiquat chloride on gradients of shoot growth within spring barley plants (cv. Koru) were determined in two small-scale field experiments. Mepiquat chloride was applied at either the lemma primordium stage or the late carpel primordium stage of spike development in the main shoot. The shoot dry weight, stem length, spike length, number and size of florets and floret developmental score were measured for all shoots, over the period from the lemma primordium stage of main shoot spike development to the late milk stage of grain development.Lemma primordium mepiquat chloride increased the size and developmental score of later-formed shorter shoots pre-anthesis while delaying the spike development of the main shoot and other longer shoots by up to 4 days. The overall effect was to produce plants with a reduced range of shoot and spike sizes from the end of floret initiation in the main shoot until maturity. In addition, there was a slight increase in the number of shoots per plant in both experiments. Gradients of carpel development and carpel width along the spike were reduced in all treated spikes by the time of floret abortion in the main shoot but the effects were more noticeable in shorter shoots. The number of florets initiated per plant was increased by 21–22%. All shoots contributed to the larger number of florets but again the major additions came from the shorter shoots. The few extra florets initiated in longer shoots were lost during abortion of distal florets while the 2–5 extra florets on shorter shoots were retained to give extra grains at maturity.Application of mepiquat chloride at the late carpel primordium stage had little effect on gradients of spike size or on number, size and development of florets.
The effect of system of harvesting grass for silage on the output of silage and milk per hectare
Authors: Small J. C. , Gordon F. J. 
Published: March 2009

SummaryFour systems of harvesting grass for silage were evaluated in terms of in-field losses, in-silo losses and milk output per hectare. The systems were: single-chop flail harvester direct cutting (SCD); doublechop flail harvester direct cutting (DCD); mown with a rotary mower and picked up with a precisionchop harvester either immediately (PCU) or after wilting until the dry-matter concentration had increased by approximately 100 g/kg (PCW). The in-field and in-silo losses were measured at each of three consecutive harvests during 1984 and during the following winter the resulting silages were evaluated through eight British Friesian cows in a balanced change-over design experiment using four periods each of 5 weeks duration.There was a greater quantity of herbage ensiled with the two direct cutting systems (SCD and DCD) than with the systems involving pre-mowing and picking up with the ensiled yields, being 12·4, 11·8, 10·8 and 10·8t OM/ha for the SCD, DCD, PCU and PCW systems respectively. These differences were only partly reflected in greater mechanical in-field losses with the pre-mown systems.Losses during the in-silo period tended to be greater with the wilted than the unwilted silages being 98, 76, 83 and 132 g/kg OM with the SCD, DCD, PCU, and PCW systems, respectively.Animals offered the PCW silage tended to have a higher silage organic-matter intake and had a significantly higher milk yield than those offered the other silages with fat corrected milk yields being 25·1, 24·5, 24·5 and 25·9 kg/day for the SCD, DCD, PCU and PCW systems, respectively. Milk outputs per hectare, at 30·3, 27·8, 25·7 and 240 for the SCD, PCD, PCU and PCW systems respectively, was lowest for the PCW treatment.