bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variations in the time of onset of the breeding season in Clun ewes
Authors: Lees J. L. 
Published: March 2009

Variations in the time of onset of the breeding season in Clun ewes have been studied during the four years 1962-65. Differences within seasons were studied in 1963 and 1964 by scattering the lambing over the first 7 months of the year. The date of first service then appears to be very highly dependent on the date of previous lambing. Time of previous weaning appears to be less important.Very highly significant differences have been found between seasonal means and these differences have been shown to be significantly related to the mean ambient temperature during a limited period between mid-summer and the mean date for the resumption of cyclic activity in the ewes. The higher this temperature the later the onset of breeding activity. Over the years individual ewes have tended to breed consistently either early or late.
The relationship between seed yield and associated characters in meadow fescue (Festuca pratensis)
Authors: Lewis Joseph 
Published: March 2009

A study was made of phenotypic correlations between seed yield and some other traits of determinable value in two bred varieties of meadow fescue. Seed yield and such characters as time of flowering, plant height and dry-matter production of spaced plants in October and at the time of anthesis were found to be closely associated.The method of path coefficient analysis was used to study the interrelationships of seed yield and its components in the causal system: fertile tiller and floret numbers, percentage fertility and thousandseed weight. This analysis corroborates the result of simple correlations in showing the importance of fertile tiller numbers and fertility as major determinants of seed yield.
Effect of zinc supplementation on performance and zinc metabolism of lambs fed forage-based diets
Authors: Kegley E. B. , Spears J. W. 
Published: March 2009

SummaryExperiments were conducted to determine the effects of zinc (Zn) supplementation on the performance and mineral metabolism of lambs fed forage-based diets containing 15–23 mg Zn/kg. In Expt 1, 20 lambs were fed a good-quality orchardgrass (21·4 mg Zn/kg) or a low-quality tall fescue (14·7 mg Zn/kg) hay and supplemental Zn (as ZnO) at 0 or 30 mg/day in a 2 x 2 factorial arrangement of treatments. Forage was fed ad libitum and all lambs received 92 g dry matter/day of a corn-based supplement which served as the carrier of the supplemental Zn. Lambs fed orchardgrass hay had a greater (P < 0·01) dry matter intake and average daily gain for the 42-day study. Zinc supplementation did not affect performance of lambs fed tall fescue but tended to improve performance in those fed orchardgrass hay. At the end of the 42-day growth phase, lambs were placed in metabolism crates for a 7-day total collection of urine and faeces. Supplemental Zn increased intake (P <0·01) and faecal excretion (P <0·01) of Zn. Absorbed Zn was greater (P < 0·05) for lambs fed supplemental Zn. There was a tendency for a forage × Zn interaction (P < 0·10) for urinary Zn excretion and retention. Urinary Zn excretion was highest in lambs fed tall fescue hay supplemented with Zn. In Expt 2, 24 lambs were fed diets consisting of ad libitum chopped tall fescue hay (23 mg Zn/kg) and 176 g/day of a corn and mineral supplement which served as the carrier of the Zn treatments. Treatments were no supplemental Zn or 30 mg/day supplemental Zn as ZnO, ZnSO4 or Zn methionine. Zinc oxide and ZnSO4 supplementation increased average daily gain (P < 0·10) and decreased feed/gain (P < 0·10) for the 56-day study when compared to control and Zn methionine-supplemented lambs.
Effects of poultry manure and mineral fertilizers on the yield of crops
Authors: Giardini L. , Pimpini F. , Borin M. , Gianquinto G. 
Published: March 2009

SUMMARYExperiments at the Experimental Station of the Agricultural University of Padova, Italy (45° 21′ N, 11° 58′ E) during 1985–89 evaluated poultry manure as a fertilizer. Two levels of fertilization (medium and high), using different mixtures of poultry manure and mineral fertilizers were compared with a non-fertilized control. The fertilization treatments were repeated each year on the same plots. All the crops tested responded strongly to fertilization, giving the following increases in yield (expressed as a percentage of the maximum yields): 30% for potato (Solanum tuberosum L.), 19% for sugarbeet (Beta vulgaris L. var. saccharifera L.), 82% for onion (Allium cepa L.), 85% for tomato (Lycopersicon esculentum Mill.) and 64% for spinach (Spinacia oleracea L.). The most effective fertilization formula varied with crop and year of cultivation. All the tested fertilization treatments had a similar effect on potato and onion, whereas the highest yields of tomato and spinach were obtained with a mixed fertilization at the highest rate of nutrients.
Radiographic pregnancy diagnosis in sheep
Authors: Wenham G. , Robinson J. J. 
Published: March 2009

SUMMARYDuring the period 1968–71, 417 ewes of various breeds were radiographed for pregnancy diagnosis during the period 60–95 days of gestation.Pregnancy per se was diagnosed by observing the presence or absence of a definite uterine outline with accuracies of 77, 97 and 100% of the period 60–70, 71–80 and 81 + days of gestation. During the periods 60–70, 71–80, 81–90 and 91 + days of gestation foetal numbers were diagnosed with an accuracy of 88, 94, 99 and 99 % respectively. Breed, size of ewe and number of foetuses carried did not affect the accuracy of diagnosis.
The amino acid composition of barley grain protein during development and germination
Authors: Smith D. B. 
Published: March 2009

SUMMARYThe amino acid composition of barley grain was studied during the maturation of the grain and during germination of the mature grain. Samples of the variety Proctor, grown at two nitrogen levels in each of the years 1969 and 1970, were analysed together with one sample of Sultan grown in 1970. It was found that during maturation the proportions of glutamic acid and proline increased and that the levels of these amino acids were highest in those samples with the highest total protein content. During ripening the proportions of lysine, alanine, aspartic acid, threonine and glycine decreased. On germination the proportions of glutamic acid and proline rapidly decreased whilst aspartic acid, lysine, alanine and glycine increased.The nutritive value of ripe barley grain is limited by its low lysine content. Whilst the germination process increases the level of lysine it is suggested that this does not increase the nutritional value of the grain due to the low level of cystine in the germinated grain.
The effect of plant density on tiller growth and morphology in barley
Authors: Kirby E. J. M. , Faris D. G. 
Published: March 2009

SUMMARYA detailed study was made of the tillering of barley plants grown at densities which ranged from 50 to 1600 plants m–2. Throughout the season the initiation of tiller buds and their growth in length and leaf number were followed, and measurements were made of leaf sheath and lamina length and lamina width. A proportion of tillers died and their positions and times of death are given.Three phases of tillering were recognized. The first, tiller bud initiation, was little affected directly by density. During the second phase, buds did not grow or did grow and emerge from the subtending leaf sheath. If they grew, there was no difference in growth rate of tillers at different densities. At the higher densities fewer buds developed, and the morphology of those tillers which did grow was affected by density. This suggests that the growth of the tiller bud may be controlled by levels of endogenous gibberellin, while in the final stage, growth after emergence from the subtending leaf sheath, competition for light appears to be the factor which determines whether a tiller survives to produce an ear. The data are discussed in relation to the practical importance of tillering.
The effect of feeding maize and lucerne silages on blood composition in dairy cows
Authors: Little W. , Manston R. 
Published: March 2009

SUMMARYMaize or lucerne silages were fed to two groups of cows in a large dairy herd. Metabolic profile tests carried out during the trial showed that abnormal blood chemistry such as might lead to production disease did not occur in either group.The results of feed analysis and digestibility trials showed that the two silages provided equal quantities of digestible energy but that the lucerne silage provided more digestible protein than the maize silage. Blood glucose concentrations were similar in both groups of cows but serum urea and albumin concentrations were significantly higher in the cows fed lucerne silage than in those fed maize silage. There was also evidence that lucerne silage provided slightly less available phosphorus but more calcium than the maize silage.It is concluded that maize silage, as used in these experiments, showed no tendency to lead to production disease, and furthermore the metabolic profile test provided additional information to feed analysis in making this assessment.
The non-protein nitrogen composition of grass silage:III. The composition of spoilt silages
Authors: Hughes A. D. 
Published: March 2009

SUMMARYThe nitrogenous composition of the water soluble, non-protein nitrogen fractions of three samples of high-pH-spoilt silage and one sample of overheated silage were examined in detail. The amino acid nitrogen content of the high-pH-spoilt silages declined with increasing extent of spoilage, due to a selective degradation of the amino acids. Losses of amino acids were associated with proportionate increases in the amount of volatile basic nitrogen. Lower aliphatic amines were not present and it was therefore concluded that the ultimate end product of nitrogen metabolism in high-pH-spoilt silages was ammonia. Only low concentrations of putrefaction products, such as putroscine, cadaverine and histamine were present.The composition of the non-protein nitrogen fraction of the overheated silage was unusual in that the ammonia nitrogen content was high and associated with the complete destruction of certain amino acids. The free amino acid nitrogen content was low but this was partially compensated for by a very high ‘peptide’ nitrogen content. There was no evidence of putrefaction products in this silage.
A study of growth in calves:II. Relative growth in muscles
Authors: Butterfield R. M. , Johnson E. R. 
Published: March 2009

SUMMARYThe growth patterns of impetus groups of muscles were mostly not significantly affected by rate of growth of the musculature. One small group – the low/average impetus muscles – had a significantly lower ‘b’ value in the calves fed at a high plane. It appears that under differences of feeding encountered commercially, no changes of practical importance in the relative growth of muscles are likely to be produced which are attributable to rate of growth of the musculature.
A study of growth in calves:III. Energy and nitrogen efficiencies of growth of carcass tissues
Authors: Pryor W. J. , Johnson E. R. 
Published: March 2009

SUMMARYThe gross energy and nitrogen contents of muscle, fat, and connective tissue of calves were determined, and from these data and feed analyses the gross energetic (GEE) and nitrogen efficiency (GNE) of growth, and the gross efficiencies of accretion since birth (GEA, GNA) were calculated.The percentage range of actual efficiency values for calves were GEE 55·3–7·7, GEA 18·1–1·4, GNE 58·1–22·8, and GNA 28·1–7·3. Within each treatment group these values were higher in the heavier calves. An hypothesis for the apparent temporary rise in these values in the heavier calves is that a compensatory mechanism acts in calves on low energy and possibly low N intake to enable them better to utilize their food. The results were obtained in calves whose diet was comprised of a reconstituted milk of low-solid content which led to low growth rates.
Studies on the digestibility and utilization of the nitrogen of irradiated rumen bacteria by rats
Authors: Mason V. C. , Palmer R. 
Published: March 2009

SUMMARYRumen bacteria were isolated from the rumen contents of eight Friesian cattle that had been fed a barley-soyabean diet. These preparations were freeze-dried, irradiated with 1 Mrad and analysed for various nitrogenous components.In nitrogen utilization studies involving both young and adult rats it was observed that the ‘true’ digestibility of the bacterial nitrogen was about 80%, while the net protein utilization (NPU) value was approximately 57.It was concluded that about 20% of the bacterial nitrogen, mainly incorporated in the cell wall, was not absorbed by the rat. On the other hand, about 71% of the absorbed nitrogen was utilized by the growing rat for tissue synthesis.Irradiation with 1 Mrad killed virtually all the rumen bacteria without adversely influencing the nutritional value of the bacterial protein.
Within-animal variances for flow rates of metabolites in an open-compartment model with continuous isotope infusion in sheep
Authors: Smith Helen K. , Milne J. A. , Mayes R. W. 
Published: March 2009

SUMMARYFlow rates of metabolites in an open-compartment model can be calculated from specific activity measurements taken at equilibrium during continuous infusion of an isotope. The within-animal variance gives an estimate of the precision of the flow rate.The Jack-knife method of calculating within-animal variances is described. It was evaluated using simulated data, and shown to be superior to a simpler method, the Single Section method.The increase in experimental accuracy caused by increasing the number of specific activity samples per animal depends on the ratio of between- to within-animal variance components (B/W). For three experiments with sheep, 23 of the 30 values B/W for the different flow rates ranged from 0·25 to 1·5. For this range between six and 12 samples per animal are needed.
Further observations on the utility of N2-fixing micro-organisms in the phyllosphere of cereals
Authors: Samanta R. , Sen S. P. 
Published: March 2009

SUMMARYThe utility of spraying some Na-fixing micro-organisms on rice (cv. Masuri and IR-26) and wheat (cv. Sonalika) leaves grown both in N2-less sand culture and under field conditions was examined. All the growth variables studied, including dry weight, chlorophyll content and N content of plants, were enhanced appreciably in N-less sand culture and under field conditions. The yield of rice cv. IR-26 per unit area was more than doubled or nearly so with Pseudomonas azotocolUgans, Ps. azotogensis, Klebsiella pneumoniae KUPBR2, K. pneumoniae KUP4, KUP6D, KUP7D, Azospirillum brasilense, Xanthobacter fiavus and K. rubiacearum. When rice cv. Masuri was used the grain weight was doubled by A. brasilense, Ps. azotocolUgans, Ps. azotogensis, KUPBR2, and KUP6D. Grain N content was increased appreciably in mostcases. The organisms also reduced acetylene to ethylene in the phyllosphere. In wheat cv. Sonalika grown in N-less sand culture, KUP4, KUPBR2, Ps. azotocolligans, A. brasilense, X. flavus, and KUP6D each doubled the N content of plants. Under field conditions Ps. azotocolligans gave the highest grain yield although grain yield was doubled by a large number of strains. N content of grains was also increased appreciably, the best result being given by KUP4.
Crop production and water-use. III. The development and validation of a water-use model for potatoes
Authors: Hamer P. J. C. , Carr M. K. V. , Wright E. 
Published: March 2009

SUMMARYAs a prerequisite for developing crop-yield/water-use functions for potatoes using the results of historical irrigation experiments, it was necessary to develop a water-use model which could operate with a limited data set. The general form of this model has been reported by Wright et al. (1994), and its application to the sugarbeet crop by Hamer et al. (1994). In this paper the development and validation of the model for potatoes is described.The canopy was modelled in terms of intercepted incoming solar radiation using functions based on thermal time and time. Four phases of growth were identified: emergence, expansion, plateau and senescence. An empirical drought factor was included to allow for the effects of water stress on canopy development during the expansion phase. Root development was described using a two-phase model: linear and maximum depth (both time dependent).Independent data from various sources were then used to validate the model in terms of its capacity to predict crop canopy development, with and without drought stress, soil water extraction at different depths and soil water deficits during the season. The study confirmed the validity of the model for predicting the water-use of potatoes.
Nature and availability of residual phosphorus in longterm fertilized pasture soils in New Zealand
Authors: Condron L. M. , Goh K. M. 
Published: March 2009

SUMMARYThe nature and availability of phosphorus in long-term fertilized pasture soils was investigated in a series of field trials, which included liming, N fertilizer and cultivation and involved monitoring plant P uptake and changes in topsoil (0–7·5 cm) P fractions for 2 years (1982–83). Liming increased soil organic P mineralization. This was indicated by significant decreases in extractable organic P and concomitant increases in microbial biomass P in the limed soils, although these changes in soil P had no significant effect on pasture yield and P uptake. On the other hand, N fertilizer increased pasture yield and P uptake but had little effect on the amounts of P in the different soil P fractions. In the cultivated soils, increases in plant-available inorganic P were attributed to the release of P during decomposition of plant residues, while the maintenance of fallow conditions decreased amounts of microbial P in these soils.
Effects of applied plant growth substances on pod set in broad beans (Vicia faba var. major)
Authors: Rylott P. D. , Smith M. L. 
Published: March 2009

SUMMARYThe effects on flower drop and pod set of applications of either the auxin 4-choloroindole, the cytokinin 6-benzylaminopurine (BAP) or gibberellic acid (GA3) to every flower, 1 day before or 1 day after tripping, were studied in broad bean plants grown in a glasshouse in 1988. Control plants shed most of their flowers; pods that did set originated primarily from flowers at proximal positions on the raceme. Most pods set on the lower part of the reproductive portion of the control plants. Chloroindole and GA3 application before tripping had no significant effect on pod-set pattern. However, GA3 applied after tripping significantly enhanced pod set at proximal flowers by 21% but inter-raceme pod set was not significantly altered. Chloroindole applied after tripping significantly increased pod set, particularly at proximal flower positions on the raceme; this treatment increased inter-raceme pod set but the increase was significant only for the basal four racemes and racemes 11, 12 and 13. Application of BAP before or after tripping resulted in almost complete pod set on all racemes; but greater flower drop was observed on the uppermost five racemes of plants treated after tripping than on corresponding racemes of plants treated before tripping. The effects of BAP, chloroindole or GA3 treatment were not due to changes in the synchrony of flower opening. An adequate supply of a cytokinin appeared to be necessary at or before pollination to initiate changes in reproductive organs to prepare them to become net attractors of assimilates from other plant parts. Auxin and gibberellin were only effective in promoting fruit set 24 h after tripping. An adequate supply of auxin, and perhaps of gibberellin, in balance with cytokinin appears to be required after pollination to maintain the flow of adequate assimilates to enable further pod development and for maturation to proceed.
Effect of trenbolone acetate on urea metabolism in cattle fed low-protein roughage diets
Authors: Hunter R. A. , Magner T. 
Published: March 2009

SUMMARYIn two experiments using cattle implanted with 0 or 300 mg trenbolone acetate and fed restricted diets of low-protein roughage, urea synthesis was measured by plasma dilution of a single intravenous injection of [14C]urea. Urea flow to the gut was calculated as the difference between synthesis and urinary urea output. Because rumen ammonia concentrations were only c. 1 mg/1, it was assumed that urea transfer from the gut to blood was negligible.In the first experiment, fistulated heifers treated with trenbolone acetate synthesized significantly (P < 0·05) less urea (0·8 v. 1·2 g/h) and had a tendency to excrete less (P = 0·08) urea in urine (0·04 v. 0·14 g/h) and to have a lower (P = 0·07) flow of urea into the gut (0·8 v. 1·1 g/h) than untreated animals. They also had significantly (P < 0·01) lower rumen digestion rates, determined from disappearance of feed dry matter from nylon bags suspended in the rumen for 48 h.In the second experiment, steers treated with trenbolone acetate synthesized significantly (P < 0·05) less urea (1·0 v. 1·9 g/h) and had a significantly (P < 0·05) lower flow of urea into the gut (0·9 v. 1·8 g/h) than untreated steers.The results were consistent with an hypothesized sequence of events resulting from treatment with trenbolone acetate. The sequence proposed was a decrease in the rate of tissue protein breakdown, a decrease in the rate of urea synthesis from de-amination of amino acids, a decrease in the amount of urea recycled to the rumen, a decreased rumen digestion rate and thus a decrease in feed intake.
Growth and development in beef cattle. 1. Direct and residual effects of plane of nutrition during early life on components of gain and food efficiency
Authors: Patterson D. C. , Steen R. W. J. , Kilpatrick D. J. 
Published: March 2009

SUMMARYLow, medium and high planes of nutrition were imposed on Friesian calves from 1 to 13 weeks of age (Period 1) and factorially arranged with low and high planes of nutrition in the 13–25 week period (Period 2). In the final (residual) period, from 25 weeks to slaughter, all animals were given the same high plane diet comprising 3·5 kg of concentrates and grass silage ad libitum. The different planes of nutrition were achieved by offering restricted allowances of milk replacer or concentrates with grass silage ad libitum. Representative animals were slaughtered at 1, 13 and 25 weeks of age while the remaining animals were slaughtered at mean liveweights of 503 and 553 kg. Over 2 years, a total of 120 Friesian steers were taken through to the final slaughter point, with 60 additional animals being slaughtered at interim stages. The animals were housed in non-bedded accommodation throughout the study and the calves were born in January of each year. The ME intake of the low plane animals in Period 1 was 0·55 that of the high plane animals and produced liveweight (LW), empty body (EBW), carcass (CW), non-carcass (NCW) and alimentary tract (ALW) weight gains which were 0·60, 0·46, 0·47, 0·44 and 0·55 of the gains of the high plane animals. In Period 2 the low plane animals had ME intakes which were 0·69 of the high plane animals and produced proportional gains of 0·57, 0·48, 0·45, 0·51 and 0·56 respectively. Previously restricted animals had higher rates of gain subsequently and the indices for weight compensation by the final slaughter point in LW, EBW, CW, NCW and ALW for the low plane treatments in Period 1 were 0·72, 0·82, 0·89, 0·73 and 0·97 while indices for low v. high in Period 2 were 0·82, 0·82, 0·79, 0·86 and 0·95. With lower plane animals, food intakes/liveweight0·75 were significantly higher during the compensating period. Calves which had been restricted in either of the early periods had significantly improved food conversion efficiency during the compensating period but lifetime food efficiency was not affected by plane of nutrition in early life.