bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of leaf shear breaking load on the feeding value of perennial ryegrass (Lolium perenne) for sheep
Authors: Inoué T. , Brookes I. M. , John A. , Hunt W. F. , Barry T. N. 
Published: March 2009

SummaryTwo populations of perennial ryegrass (PRG) (Lolium perenne L.) were selected for low (LS) and high leaf shear breaking load (HS) in 1984 at DSIR, Palmerston North. Leaf shear breaking load for the LS group was c. 41% lower than for the HS group and the LS selection had significantly shorter, narrower leaves and smaller leaf cross-sectional areas than the HS selection. LS leaves were c. 27% less resistant to shear than HS leaves per unit of cross-sectional area. The lower leaf shear strength in the LS selection was associated with a significantly lower concentration of sclerenchyma tissues in the leaf cross-sectional area compared with the HS selection. The total shear load required to break down the same dry weight of leaves to 1 mm particle size (leaf index of masticatory load) was calculated and shown to be influenced by the differences in leaf morphology. LS leaves were estimated to have a 21% lower index of masticatory load than HS leaves when both were grown under optimum climatic conditions.
Influence of soil type, crop management and weather on the recovery of 15N-labelled fertilizer applied to winter wheat in spring
Authors: Powlson D. S. , Hart P. B. S. , Poulton P. R. , Johnston A. E. , Jenkinson D. S. 
Published: March 2009

SUMMARY15N-labelled fertilizer was applied, in spring, to winter wheat crops in nine experiments in eastern England over a period of 4 years. Five were on Batcombe Series silty clay loam, two on Beccles Series sandy clay loam (with a mole-drained clay subsoil) and two on Cottenham Series sandy loam. In three of the experiments, different rates of fertilizer N were applied (up to 234 kg N/ha); in the others, a single rate (between 140 and 230 kg/ha) was used.Recovery of fertilizer N in the above-ground crop (grain, chaff, straw and stubble) ranged from 46 to 87% (mean 68%). The quantity of fertilizer N retained in the soil at harvest was remarkably constant between different experiments, averaging 18% where labelled N was applied as 15NH415NO3, but less (7–14%) where K16NO3 was applied. Of the labelled N present in soil to a depth of 70 cm, 84–88% was within the cultivated layer (0–23 cm).L70 = 5(± 1 63) + 0·264(±00352) R3accounted for 73% of the variation in the data where: L70 = percentage loss of fertilizer N from the crop: soil system, defined as percentage of labelled N not recovered in crop or in soil to a depth of 70 cm at the time of harvest; R3 = rainfall (in mm) in the 3 weeks following application of N fertilizer.There was a tendency for percentage loss of fertilizer N to be greater when a quantity of N in excess of that required for maximum grain yield was applied. However, a multiple regression relating loss both to rainfall and to quantity of N applied accounted for no more variance than the regression involving rainfall alone. In one experiment, early and late sowing were compared on the first wheat crop that followed oats. The loss of N from the early-sown crop, given fertilizer N late in spring, was only 4% compared with 26 % from the later-sown crop given N at the same time, so that sowing date had a marked effect on the loss of spring-applied fertilizer N.Uptake of unlabelled N, derived from mineralization of organic N in soil, autumn-applied N (where given) and from atmospheric inputs, was < 30 kg/ha on a low organic matter (0·08% total N) sandy soil but > 130 kg/ha when wheat followed potatoes or beans on soil containing c. 0·15 % total N. Unlabelled N accounted for 20–50% of the total N content of fertilized crops at harvest. About 50% of this unlabelled N had already been taken up by the time of fertilizer application in spring and the final quantity was closely correlated with the amount present in the crop at this time. Applications of labelled fertilizer N tended to increase uptake of unlabelled N by 10–20 kg/ha, compared to controls receiving no N fertilizer. This was probably due to pool substitution, i.e. labelled inorganic N standing proxy for unlabelled inorganic N that would otherwise have been immobilized or denitrified.
Planting date and density effects on six pigeonpea (Cajanus cajan) cultivars at three Nigerian Savanna locations
Authors: Akinola J. O. , Oyejola B. A. 
Published: March 2009

SummaryAn experiment was conducted to investigate the effects of planting pigeonpea in May, June or July at Mokwa and June or July at Shika and Kano, Nigeria at population densities of 18·5×103, 27·8×103, 55·5×103, 111×103, 222×103and 444×103plants/ha on dry matter (DM) and seed yields of cultivars Local, UQ50, 3D8103, 3D8104, 3D8111 and 3D8112 in the 1974/75 season. Planting in May had no above-ground DM yield advantage over planting in June at Mokwa. Planting in June gave higher yields than planting in July irrespective of site, except for the short, early maturing, soya-type cultivar 3D8103 at Shika. Cultivar responses to density were inconsistent between sites and also between dates at Shika and Kano. Cultivars Local, UQ50 and 3D8104 showed the highest DM yield at all sites. Leaf DM yield tended to decline as planting was delayed but was highest at densities of 111×103or 222×103plants/ha for May and June-planted cultivars Local, UQ50, 3D8104 and 3D8112, which showed potential as feed supplements for poultry. Reasons were advanced for the variability in pod yield responses to planting date and density between the different pigeonpea cultivars. Root DM yields were proportional to above-ground DM yield but, over all cultivars, root yield was unaffected by planting date at Shika.Seed yield was highest from the June sowing, cv. 3D8104 was the most productive and the optimum densities were 27·8×103plants/ha for the larger-sized cultivars Local and UQ50, 55·5×103plants/ha for the medium-sized cultivars 3D8104, 3D8111 and 3D8112, and 444×103for cv. 3D8103. A complementary study over 13 years showed that the seed yield of intermediate and late maturing pigeonpeas was strongly and linearly related to total annual rainfall.
Effect of virginiamycin on digestibility of nutrients, blood and immunologic parameters, and quality of meat in veal calves
Authors: Skřivanová V. , Marounek M. , Šimůnek J. , Benda V. 
Published: March 2009

SummaryExperiments were carried out in 1992 with ten male calves, 4 weeks old initially, on a milk diet. Five calves received 80 mg/head virginiamycin (a feed antibiotic) daily for about 14 weeks. Virginiamycin significantly (P < 0·05) increased weight gains (122±2 kg ν. 114±2 kg), digestibility of ash, serum iron and haemoglobin. The feed intake per 1 kg of gain was non-significantly lowered in the virginiamycin group. The phagocytic activity of granulocytes in blood samples of treated calves was slightly increased with a concomitant decrease in the concentration of immunoglobulins. Meat of virginiamycin-fed calves tended to be somewhat darker, to contain more K, Na and Fe and to have a higher pH 24 h post mortem. There were no major differences in other qualitative characteristics of meat between the groups.
Comparative rates of emergence and leaf appearance in wild oats (Avena fatua), winter barley (Hordeum sativum) and winter wheat (Triticum aestivum)
Authors: Cousens R. D. , Johnson M. P. , Weaver S. E. , Martin T. D. , Blair A. M. 
Published: March 2009

SUMMARYWinter barley cv. Igri, winter wheat cv. Avalon and spring wild oats (Avena fatua) were studied in monocultures in pots and in the field. The field experiments were located near Bristol and Bury St Edmunds in 1988/89. Pot sowings were monthly, whereas there was a single sowing date for each of the two field locations. Base temperatures for emergence in pots were 2·2, 1·3 and 2·3 °C for barley, wheat andA. fatuarespectively. Barley was consistently the fastest to emerge. Leaf number was strongly correlated with photothermal time from emergence, with barley producing leaves at the greatest rate. Base temperatures for leaf appearance were −6, −5 and −3 °C for barley, wheat andA. fatuarespectively. The field studies confirmed the ranking of the species based on the pot experiments. Both a model based on photothermal time and one based on rate of change of daylength at emergence gave good descriptions of the data. It is argued that correlations of rates of development with individual environmental variables are not sufficient to deduce the underlying mechanisms.
Intravaginal SC-9880-progesterone treatments in the synchronization of oestrus in cyclic sheep
Authors: Gordon I. , Maher P. G. 
Published: March 2009

SUMMARYThe mating response and lambing outcome in fifty-three sheep was studied after treatment with intravaginal sponges during October (normal breeding season). Bach pessary carried a dose of 30 mg ‘Cronolone’ (9α-fluoro-11β-hydroxy-17α-acetoxyprogesterone; SC-9880, G. D. Searle) in finely dispersed form and was inserted for 14 days. Half the number of pessaries carried an additional dose of 400 mg progesterone. Breeding was by natural service, using 10% rams. Ninety per cent of the fifty ewes bred immediately after treatment conceived; the average number of lambs/conception was 1·9. Sheep treated with ‘Cronolone’/progesterone pessaries showed a marginal and non-significant advantage over those treated with ‘Cronolone’. The application was effective in ensuring the birth of most lambs (87% of total) within a period of 1 week.
Culture and fertilization of sheep ovarian oocytes:II. Timing of nuclear maturation in oocytes cultured in growth medium
Authors: Crosby T. F. , Gordon I. 
Published: March 2009

SUMMARYIn 450 oocytes, recovered from the vesicular follicles of prepuberal lambs and cultured in growth medium for 2–48 h, 76·4% resumed meiosis. The first evidence of polar body extrusion was at 18 h; maturation was completed in most oocytes by 25–27 h.
A study of growth in calves:I. Carcass tissues
Authors: Butterfield R. M. , Johnson E. R. , Pryor W. J. 
Published: March 2009

SUMMARYCalves were slaughtered at predetermined weights after being fed individually on fresh and reconstituted whole milk at three levels. The highest level of feeding was ad libitum and the lowest was aimed at keeping the calves at their birth weight for 72 days before providing extra milk to allow growth to proceed.Dressing percentage did not decline with age as it did in a previous experiment using roughage in the diet. The faster-grown calves had a higher dressing percentage. It is concluded that both rate of growth and the physical nature of the diet influenced dressing percentage.Muscle: bone ratio and the amount of fat and bone in the carcass were not significantly affected by the rate of live-weight increase.
Yield, nutritive value and ensiling characteristics of whole-crop spring cereals
Authors: Lawes D. A. , Jones D. I. H. 
Published: March 2009

SUMMARYThe dry-matter yield, in vitro digestibility and crude protein content of four varieties of spring cereals (one barley, one wheat and two oats) were examined at weekly intervals at two levels of nitrogen fertilization during two successive years. The ensiling characteristics of crops cut at two dates were also determined. Dry-matter yields increased until the end of July. Digestibility and crude protein content declined until mid July when values of 56–60 and 6–7% for the barley and wheat, and 53–55 and 5–6% for the oats respectively were maintained. Crops of all varieties were suitable for ensiling at maximum yield.Other experiments investigating level of whole-crop cereal yields obtainable with higher levels of fertility produced yields of over 16 metric tons D.M./ha with applications of 200–250 kg N, P2 O5 and K2O per hectare.
Breeding of maize for low rainfall areas of Kenya:1. The reliability of yield of early and later maturing maizes
Authors: Dowker B. D. 
Published: March 2009

SUMMARYA trial to compare the reliability of yield of a quick maturing maize (Taboran) with the medium maturity local maize was carried out at two low rainfall sites in Southern Province, Kenya, from 1957 to 1961. Each variety was grown at two spacings, giving plant densities of 1·8 and 3·6 pl./m2. Results showed a consistent difference in ‘days to 50% silking’, Taboran being on average 17 days earlier than Local White. There was no overall difference between varieties or spacings in yield per ha. There were highly significant interactions of seasons with varieties and with spacings. These were interpreted in terms of different linear yield/rainfall relationships for each variety and each spacing. A variety/spacing interaction was also demonstrated.Analysis of components of yield showed that similar linear relations between rainfall and each yield component obtained. There were significant differences between varieties and between spacings in both mean number of cobs per plant and yield per cob. Taboran had a higher mean number of cobs per plant and Local White a higher mean yield per cob. Seasons x varieties interactions were again interpreted in linear regression terms. Earliness of the Taboran variety often enabled plants to produce silks before development was arrested by drought and so was responsible for its relatively high mean number of cobs per plant in low rainfall seasons, giving it an advantage over Local White in yield per unit area in such circumstances. Taboran was shown to have a potential value in local agriculture, because of its consistency of yield. The expected advantage or disadvantage of Taboran over Local White was calculated for an area of known rainfall from the respective yield/rainfall regressions and the seasonal rainfall probabilities.Selection for earliness was shown to be of basic importance in a breeding programme for the low rainfall areas. Within a specified early maturity range, selection for yield improvement through the yield per cob component could be practised. A maturity length similar to Taboran would ensure a high value of mean cobs per plant in low rainfall season, i.e. confer the necessary reliability of yield.
Effect of phosphorus, farmyard manure and nitrogen on some soil properties in a soya bean-maize sequence
Authors: Nimje P. M. , Seth Jagdish 
Published: March 2009

SUMMARYThe effects of applying phosphorus, farmyard manure (FYM) and nitrogen on some soil properties were studied at the end of 2 years of field experimentation at New Delhi, India. Each year a crop of soya bean sown in the rainy season received phosphorus and farmyard manure and maize sown in winter received nitrogen fertilizer. Phosphorus was applied to soya bean at 0, 40 and 80 kg P2O5/ha, farmyard manure at 0 and 15 t/ha and nitrogen to maize at 0, 60 and 120 kg N/ha. Phosphorus application increased organic C, total N and available P status of the soil. It also improved bulk density and water-holding capacity of the soil. Farmyard manure increased organic C, total N, available P and K and pH of the soil, but decreased EC and bulk density of the soil. Water-holding capacity of the soil was increased by FYM. N fertilizer increased organic C and total N only.
The utilization of leaf wax by N2-fixing micro-organisms on the leaf surface
Authors: Samanta R. , Dutta A. K. , Sen S. P. 
Published: March 2009

SUMMARYThe possibility of utilization of leaf wax by N2-fixing micro-organisms on the leaf surface of plants was examined. Chloroform and n-hexane extractable wax could be isolated in significant amounts, ranging between 0·13 and 6·83 g/kg fresh weight from leaves of rice cv. IR·26, wheat cv. Sonalika, jute cv. JRO 632, pigeon pea, Ficus benghalensis, F. religiosa, Eichornia crassipes, Calotropis procera and Cocos nucifera. Pigeon pea and coconut leaves were very rich in wax. The utilization of leaf wax was studied by observing the growth of micro-organisms in Burk's N-less DN2 medium containing 0·025% yeast extract and jute or coconut leaf wax as the sole C source. A 2·fold increase in growth was observed as compared with the control containing no wax. The most growth was exhibited by Pseudomonas azotogensis, P8. azotocolligans, Xanthobacter flavus, Azotobacter paspali 23A and Klebsiella pneumoniae Kupbr2. Utilization of wax components was studied by comparing the amounts of acetylated alcohols and methyl esters of fatty acids in leaves inoculated with those untreated with bacteria after separation of the components by gas chromatography. A strain of K. pneumoniae KUP4, the association of which very remarkably improved the growth of jute plants, was found to utilize particularly C10–, C13– and C16– saturatedfatty acids and C15–, C18–, C25–, C26– and C27– fatty alcohols. It is suggested that leaf wax may act partly as an energy substrate for growth of N2-fixing micro-organisms on the leaf surface.
Effects of sowing date, sowing density and nitrogen supply on leaf extension in spring barley
Authors: Maan A. A. S. , Wright D. , Alcock M. B. 
Published: March 2009

SUMMARYThree pot experiments were performed in unheated glasshouses at the University College of North Wales College Farm, Aber, Gwynedd in 1980–1983. Two experiments tested the effects of sowing date and N supply, the third sowing density and nitrogen supply. Extension growth of main-stem leaves was measured by ruler and expressed in thermal time units to allow comparisons between sowing dates. Rate and duration of leaf extension were determined from linear regressions of leaf length against thermal time.Increasing N supply increased leaf extension rate but had no significant effects on leaf extension duration. Leaf extension rate increased with leaf position on the main shoot, but decreased slightly in leaves extending at the time of stem elongation. Leaf extension duration also increased with leaf position on the main shoot and was related to mean temperature during the leaf extension phase. Plants sown in September were able to compensate for lower radiation receipts by having a faster rate and longer duration of leaf extension, by producing larger leaves with a greater specific lamina area and by partitioning a greater proportion of extension growth into lamina and less into sheaths. In plants sown in June, the largest leaf occurred at a lower stem node and leaves emerging later showed a strong response to N. It is suggested that this is attributable to earlier onset of internal competition for assimilates. Variation in leaf extension rate was the main factor influencing variation in final leaf area. There was a strong positive relationship between leaf extension rate and leaf N content.Increasing sowing density increased the area of the first four leaves on the main shoot and decreased that of later leaves, changes mainly associated with changes in leaf extension duration. It is concluded that progress in the modelling of leaf area expansion, light interception and dry matter production requires more information about how sowing date, sowing density and N supply interact to influence crop development and leaf growth.
Effects ofTrypanosoma vivaxinfection during pregnancy on feed intake, nitrogen retention and liveweight changes in West African Dwarf ewes
Authors: Akinbamijo O. O. , Reynolds L. , Gort G. 
Published: March 2009

SUMMARYThe effects of infection withT. vivaxin mid- or late pregnancy on food intake and utilization, liveweight changes, abortion rate and lamb growth rate were investigated in West African Dwarf ewes at lbadan, Nigeria in 1990. Rate of liveweight gain by ewes infected during mid-pregnancy (IMH) was16 g/day compared with 33 and 37 g/day for the uninfected ewes offered medium (CM) or high (CH) plane diets. Although digestibility coefficients were not affected, intake of digestible organic matter was higher in CH ewes than in IMH and CM ewes. Nitrogen retention at mid-pregnancy on a metabolic size basis was higher in CH ewes than in CM and IMH ewes.Lamb birth weight and survival rate were lower in infected ewes. Ewes infected in mid-pregnancy (IMH) and in late pregnancy (ILH) had mean birth weights of 1·4 and 1·0 kg compared with CM and CH ewes, which had mean birth weights of 1·9 and 2·0 kg respectively. Observed survival rates were 63, 15, 75 and 80% for lambs nursed by IMH, ILH, CM and CH ewes respectively. During the first 6 weeks postpartum, lamb growth rate in all groups did not differ. However, during weeks 7–12 postpartum, lambs nursed by IMH ewes had significantly lower growth rates. Weaning weight was also lower in lambs from IMH (5·0 kg) dams than in lambs from CM and CH dams (7·1 kg). Infection during late pregnancy was more severe and all infected ewes lost weight due to reduced feed intake and fever.T. vivaxinfection in sheep is responsible for reproductive wastage, abortion, poor lamb growth and ewe mortality.
Effects of raw and treated jack beans(Canavalia ensiformis) and of canavanine on the short-term feed intake of chicks and pigs
Authors: Belmar R. , Morris T. R. 
Published: March 2009

SUMMARYFour experiments were conducted in the Yucatán, Mexico, in 1991 and 1992 to study feed intake in 24 h trials with chicks and pigs fed diets containing either raw or treated jack beans or conventional diets with added canavanine.Feed intake of chicks in the first hour was markedly reduced and feed intake of pigs was severely reduced when raw jack beans (300 g/kg for chicks, 250 g/kg for pigs) were included in their diets. Feed intake of pigs diminished to a greater extent than that of chicks when treated beans (300 g/kg) were included in the diet. Short-term feed intake of chicks was not affected when canavanine (3·5 g/kg) was added to a sorghum-soyabean diet. However, pigs showed a large drop in feed intake when canavanine was added to a maize-soya diet at only 0·8 g/kg. It was concluded that in both species the anti-nutritional factors in jack beans cause a rapid reduction in feed intake which precedes a depression in growth rate. The initial feed intake depression in pigs could be partly attributed to canavanine remaining in the jack beans after treatment. In the chicks' case, however, rejection of a diet containing treated jack bean was due to anti-nutritional factor(s) other than residual canavanine.
Moisture stress impact on N partitioning, N remobilization and N-use efficiency in beans (Phaseolus vulgaris)
Authors: Foster E. F. , Pajarito A. , Acosta-Gallegos J. 
Published: March 2009

SUMMARYField and glasshouse studies were conducted in Durango, Mexico in 1987 and in East Lansing, Michigan, USA in 1989, respectively, to determine the effects of moisture deficits upon N-use efficiency (NUE), N partitioning and remobilization, and N harvest index (NHI) in edible beans (Phaseolus vulgaris L.). Four indeterminate, semi-prostrate genotypes adapted to the semi-arid high plains of Mexico, Pinto Nacional-1, Durango 222, L1213–2 and Bayo Madero, were used in the field study and Pinto Nacional-1 and Bayo Madero were used in the glasshouse study. A Xerosol Haplic soil was used in the field study and a Spinks loamy sand in the glasshouse study. A moisture deficit was induced by use of temporary rainshelters in the field and curtailment of water in the glasshouse. Plants were sampled periodically and subdivided into leaves, stems, pods and flowers, and roots (in the glasshouse study only) for determination of dry weight and total N content. Water-use efficiency was determined in the glasshouse study. A moderate moisture deficit (drought intensity index 0·41) reduced yield by 41% in comparison with non-stressed yield (from 134·3 down to 79·2 g/m2) and resulted in a greater percentage of seed-N derived from N that had been redistributed from the leaf, indicating that N partitioning was not impaired by this degree of stress. In contrast, N remobilization was greatly reduced by a more severe moisture deficit (drought intensity index 0·92), which resulted in yield losses of 92% (from 2·19 down to 0·17 g/pot). These results suggest that N remobilization may be an important drought adaptation strategy under moderate or intermittent moisture deficits. Severe moisture deficits reduced NHI, harvest index (HI), NUE and water-use efficiency (WUE) when WUE was expressed as seed dry weight per litre water used. Genotypic variability was observed for NHI, HI and NUE.