bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of night enclosure and extensive walking on the productivity of zebu cattle
Authors: Nicholson M. J. 
Published: March 2009

SummaryThe effects of night enclosure and walking 3000 km on growing and breeding cattle were examined over an 8-month period. Walking consisted of an 8 h walk of 40 km every 3rd day and experimental cattle were enclosed each night for 11 h. In addition, all cattle were allowed water once every 3 days. In cattle which both walked and were enclosed, a reduction of nearly 40% in grazing time was recorded. This was associated with a depression of dry-matter intake of only 12%, suggesting an intensification of eating in response to a restriction of grazing time. The overall effects of walking and enclosing on productivity, as determined by adult weight loss, calf and weaner growth, calving percentage and birth weight, were negligible and masked by the greater effects of poor nutrition during the dry season which affected all the animals. It is concluded that the additional energetic requirements for walking are small and this is attributed to adaptation, fitness and a possible depression of metabolic rate. These factors may explain why the observed costs of walking were lower than those reported in the literature.
Reflexion and absorption of solar radiation by flowering canopies of oil-seed rape (Brassica napus L.)
Authors: Yates D. J. , Steven M. D. 
Published: March 2009

SummaryFlowers were present over a period of approximately 6 weeks in 12 varieties of oil-seed rape. A linear relationship was found between flower cover (maximum 74%) and photon reflectivity (400–700 nm) which increased from around 0·047 during vegetative growth to 0·195 for a canopy in full flower. Reflexion and absorption of photons by flowers reduced light available to the leaf canopy and immature pods. Spectral measurements indicate that flowering canopies reflect substantially more radiation and absorb less than vegetative canopies between 500 and 700 nm but reflect less and absorb slightly more between 400 and 500 nm.Seed yield was not strongly correlated with estimates of the radiation absorbed by the leaf canopy under the flower layer. It appears that whilst increased flower density in a canopy might be expected to contribute to increased seed yield, increased reflectivity by petals may have a negative effect on yield. Breeding for reduced petal size or for apetalous lines may result in improved yields by producing more efficient light distribution within the canopy.
Factors affecting growth and yield of short-duration pigeonpea and its potential for multiple harvests
Authors: Chauhan Y. S. , Venkataratnam N. , Sheldrake A. R. 
Published: March 2009

SummaryEnvironmental and cultural factors that may limit the yield of short-duration pigeonpea were investigated over three seasons. Plants in the peninsular Indian environment at Patancheru grew less and produced less dry matter by first-flush maturity than at Hisar, a location in northern India where the environment is considered favourable for the growth of short-duration pigeonpea. However, with a similar sowing date in June, the mean seed yields of three genotypes, ICPL 4, ICPL 81 and ICPL 87, were very similar, at about 2·3 t/ha, in both environments. This was mainly due to the higher ratio of grain to above-ground dry matter at Patancheru. In addition to the first harvest, all genotypes showed a potential for two more harvests owing to the warm winters at Patancheru. The potential for multiple harvests was particularly high in ICPL 87, which yielded 5·2 t/ha from three harvests in 1982–3, 3·6 t/ha from two harvests in 1983–4, and 4·l t/ha from three harvests in 1984–5. The optimum plant population density at Patancheru was 25–35 plants/m2 for ICPL 87, but was higher for the other two genotypes.At Patancheru, the total dry-matter and seed yield of first and subsequent harvests were significantly reduced by delaying sowing beyond June. Generally, the second- and the third-harvest yields were lower on vertisol than on alfisol under both irrigated and unirrigated conditions.The total yield of ICPL 87 from two harvests was far higher than that of a well-adapted medium-duration genotype BDN 1, grown over a similar period. The yield advantage was greater on the alfisol because of the better multiple harvest potential of this soil. The results of this study demonstrate that properly managed short-duration genotypes of pigeonpea may have considerable potential for increased yield from multiple harvests in environments where winters are warm enough to permit continued growth.
Seasonal yield changes in white clover varieties and ecotypes in Nova Scotia
Authors: Fraser Joanna 
Published: March 2009

SummaryTwo ecotypes and three varieties of white clover (Trifolium repens) of contrasting morphology were established in monoculture field plots in Truro, Nova Scotia (45° N) in July 1985. Destructive measurements were taken at monthly intervals from August to November 1985 and April to August 1986. The seasonal distribution of number of active stolons/m2, number of leaves, number of leaves per stolon, and lamina weight together with dry weights of leaves-I-petioles, stolons and flowers + peduncles were recorded. Number of leaves was inversely proportional to leaf weight, smaller-leaved varieties and ecotypes having higher leaf densities than large-leaved white clovers. Leaf and petiole dry-matter yields were related to leaf and number of active stolons in 1985 and to leaf weight increments in 1986. The two naturalized ecotypes exhibited considerably less leaf loss than the three varieties in a winter where mean minimum air temperatures drop to as low as – 13°C. There were considerable differences between ecotypes and between varieties in the seasonal distribution of leaves and petioles, stolon and flower dry weights over the limited time period of this study.
Effect of improved management of legumes in a legume-cereal rotation on field estimates of crop nitrogen uptake and symbiotic nitrogen fixation in northern Syria
Authors: Keatinge J. D. H. , Chapanian N. , Saxena M. C. 
Published: March 2009

SummaryImproved management compared with traditional practices common in northern Syria for growing field bean (Vicia faba L.), chickpea (Cicer arietinum), lentil (Lens culinaris), peas (Pisum sativum) and vetch (Vicia sativa) was shown to increase significantly (P < 0·001) the crop nitrogen (N) uptake and subsequent protein yields in either hay, grain or straw. This intervention more than doubled N uptake in 1982–3 when averaged over crops and locations increasing from 31·8 kg N/ha under traditional management to 68·7 kg N/ha under improved management. Improved management also increased the proportion of nitrogen uptake that was derived from symbiotic nitrogen fixation by the crop from 55 to 69%. The treatments which gave improved crop N uptake were application of phosphate fertilizer, reduced row spacing and control of weeds. Seed inoculation with rhizobia had little or no effect on N uptake or on the proportion of N that was fixed biologically by the crop. Environmental effects on productivity, as expressed by seasonal and locational differences, were as, or more, important than management-imposed effects.Differences in N uptake by barley, following either a legume crop or barley, indicated that the residual effects of the legume crop amounted to approximately 10 kg N/ha. This represents a substantial contribution to the N nutrition of a barley crop in the dry areas of northern Syria.
Effect of sodicity and zinc on soil solution chemistry of manganese under submerged conditions
Authors: Sadana U. S. , Takkar P. N. 
Published: March 2009

SummaryIn a greenhouse experiment, the effect of soil sodicity (exchangeable Na percentage 3, 10, 20, 40 and 60) and Zn (0 and 10 mg Zn/kg soil) on soil solution chemistry of Mn was investigated under submerged conditions. Calculated amounts of NaHCO3 were added to Typic Ustifluvent sandy loam soil to obtain required sodicity levels. The soil solutions collected under the atmosphere of N2 gas by gravity were analysed for pH, pE, EC and Mn. Soil submergence decreased pH and pE, and increased Mn concentrations in all the treatments. Maximum Mn concentration was obtained at 14-day submergence. Increasing sodicity levels increased soil solution pH and decreased Mn concentrations. A significant negative correlation (r = -0·74**) was observed between soil solution Mn and pH. Despite large variations in pH, pE, ionic strength and Mn concentration in soil solution, the values of expressions: pH+½log Mn2+ + ½log Pco2 and pMn+2pOH were fairly constant and close to the theoretical values of 4·4 and 17·2 respectively, indicating that the MnCO3-Mn2+ system regulated the solubility of Mn2+ in the sodic soils. Addition of ZnSO4 did not have appreciable effects on the soil solution pH, Mn and solid phases of Mn.
Effect of different combinations of light and dark regimes on the performance of egg lay events, fertility and plasma steroid hormones, during the ovulatory cycle in Peking ducks
Authors: Abdelrazik M. A. , El Sayiad Gh. A. , Marai I. F. M. , Soliman M. M. 
Published: March 2009

SummaryDifferent photoperiodic treatments within 2 types of light dark cycles ranging from 24 to 30 h were applied to Peking ducks. The first consisted of constant photoperiods (1, 8L: 16D; 2, 14 L: 10D; 3, 18L:6D; 4, 14L: 13D; 5, 14L: 16D and 6, continuous light) and the second of intermittent cycles (1, 6L:2D:2L:14p; 2, 6L:4D:2L:12D; 3, 6L:6D:2L:10D; 4, 6L:8D:2L:8D and 5, 14L:½D:3½L:6D). The traits studied varied in response according to the photoperiodic regimes used. Rate of lay and eggs laid in the modal 8 h period increased with the duration of the light period in the cycle. Sequence lengths of 1–3 eggs were most frequent under all photoperiodic regimes (constant and intermittent). Length of intra-sequence interval (h) showed an inverse relationship with length of inter-sequence interval. A pause length of 2–4 days was the most frequent for all the different light-dark cycles. Egg weight was heavier in the second season than in the first when the light period of the photoperiodic regime was long. Weights of albumin and yolk showed similar trends to egg weight. The latter differences were significant, while shell weight differences were not significant. Plasma progesterone lvels were lowest in non-laying ducks. The highest values in laying ducks were before ovulation. The highest level of cortisol was shown during the last hours of the dark period. Differences from ovulatory cycle to another were observed.
An evaluation of tree legumes on an acid ultisol in South Sumatra, Indonesia
Authors: Blair G. J. , Panjaitan Mas'ud , Ivory D. A. , Palmer B. , Sudjadi M. 
Published: March 2009

SummarySeventeen tree species (16 legumes and Eucalyptus saligna) were grown for 4 years on an Ultisol of pH 4·5 at Nakau, South Sumatra, Indonesia. Leaf and wood yields were recorded seven times during the 4-year period and mineral and plant quality measurements were made on leaf samples from the first harvest taken 2 years after transplanting. At this time, leaf and wood yields were highest from Acacia mangium but the yield of this species declined over time. Highest leaf production was recorded for Cassia siamea over the 4-year period.Mineral analyses of leaf indicated N, K, Ca and Mg to be adequate for animal production in all species. P was below the critical level for animals in all species and Na levels were adequate only in Acacia mangium and Acacia auriculiformis.Plant quality measures (ADF, NDF, lignin) suggest marked differences could be expected in potential feed value between species through differences in voluntary intake and digestibility.
The effects of nitrogen, potassium and sodium fertilizers on sugar beet
Authors: Tinker P. B. H. 
Published: March 2009

A series of forty-two factorial field trials in 1959–62 tested the effects of 0·6 and 1·2 ewt./acre of N; 0, 1·2 and 2·4 cwt./acre of K2O; and 0, 2 and 4 cwt./acre of salt on sugar beet. Extra plots received 0 and 1·8 cwt./acre of N.On average, 0·6 cwt./acre of N was more profitable than 1·2 cwt./acre. There was a positive interaction between N and Na, and a lesser one between N and K; in presence of the heavy salt dressing, or the light salt dressing and potassium the optimum rate of nitrogen was 1·0 cwt./acre.
Some aspects of the utilization of tropical forages. I. Green elephant grass at various stages of growth
Authors: Butterworth M. H. 
Published: March 2009

1. Cuts of elephant grass (Pennisetum purpureum were made at 40–60 (trial 1), 30 (trial 2), 50 (trial 3) and 70 (trial 4) days of age. Determinations of voluntary intake, digestibility coefficients, rate of passage through the gut, time spent eating and ruminating, number of boluses, rate of chewing, production of volatile fatty acids (both total and individual) were determined using individually housed sheep.2. Digestibility coefficients of crude protein declined with the level of crude protein in the forage; digestion of the crude fibre fraction declined with advancing maturity. The digestibility of N.F.E. increased with increasing maturity resulting in similar values for T.D.N. among the four cuts. Digestibility of dry matter of the grass in trial 2 was significantly higher than that for the other three trials.
Density ofTrifolium repensplants in mixed swards under intensive grazing by sheep
Authors: Hay M. J. M. , Brock J. L. , Thomas V. J. 
Published: March 2009

SUMMARYDensities of physiologically independent plants of white clover were studied in New Zealand in pastures stocked at 22·5 ewes plus lambs/ha by set stocking, rotational grazing or a combination of both systems. Plants were sampled once a month for 1 year (1984/85) by taking turves and washing out the plants. Numbers of growing points and stolon dry weight per plant were obtained. At each sampling fifty, 50 mm diameter pasture plugs were taken from each sward and growing point density and stolon mass/m2of white clover were measured. The density of white clover plants in the swards was estimated on the basis of both stolon dry weight and number of growing points.The two estimates gave similar results. There was a trend of lowest densities in set-stocked pastures (334/m2), intermediate densities in combination management pastures (431/m2) and highest densities in the rotationally grazed pastures (553/m2). The overall mean density of white clover plants was 439/m2and the range was 193–811/m2.The structure of swards under the three systems of grazing differed and this was considered to contribute towards the variation in density of white clover plants in the various swards.
The effects of diets deficient in phosphorus, phosphorus and vitamin D, or calcium, on the skeleton and teeth of the growing sheep. II. Malocclusion of the teeth
Authors: McRoberts M. R. , Hill R. , Dalgarno A. C. 
Published: March 2009

1. In growing sheep fed on a low-calcium diet for 12 months and for a similar period on a diet of adequate mineral content, a tendency for the incisor teeth to protrude beyond the maxillary pad (prognathism) was observed. This arose primarily during the repair period, and was apparently caused by poorer repair of the upper skull than of the mandible. This was not observed in animals fed on a control diet or one deficient in phosphorus and vitamin D.2. A malocclusion of molar teeth associated with poorly mineralized and extremely weak mandibles, which prevented the incisor teeth from meeting the dental pad, occurred in growing sheep fed for 12 months on a diet deficient in phosphorus and vitamin D. This defect was not observed in similar animals fed on a control diet nor in those fed on a diet of low calcium content. Treatment effects on the shape of the mandible that were apparently related to this malocclusion are described.
Selection criteria in grass breeding. IV. Effect of nitrogen and spacing on yield and its components
Authors: Lazenby Alec , Rogers H. H. 
Published: March 2009

1. The effects of applied nitrogen (0, 200, 400, 600, and 800 lb. per acre per annum) and spacing (widely spaced plants and simulated monoculture swards) on average yields and yield components of eight clones of Lolium perenne are reported for four harvests taken each year during 1962 and 1963.2. During both years, higher yields per unit area were obtained from swards than from spaced plants; the degree of difference varied from harvest to harvest.3. A greater effect of nitrogen on yield was detected in 1963 than in 1962, an effect especially marked in swards at lower rates of nitrogen application. A highly significant nitrogen x spacing interaction on yield was detected in 1963.
Crop yields from lucerne (Medicago sativa) cultivars displaying gradations in resistance to wilt (Verticillium albo-atrum)
Authors: Dixon G. R. , Kershaw C. D. , Hunter E. A. 
Published: March 2009

SummaryYields from lucerne cultivars grown on land infested with Verticillium albo-atrum, a cause of wilt disease, were studied over the period 1969–77. Field experiments established in 1969, 1971, 1972 and 1973 were maintained for periods of 4–6 years. Reactions by cvs Europe and Vertus were of principal interest. Europe is considered to be moderately susceptible, initially producing yields exceeding those of resistant types on uninfested land. In comparison cv. Vertus has considerable resistance derived from a polygenic system. In the first 2 cropping years on infested land, Europe yielded similarly to Vertus with only slight symptom expression. In year 3, Europe maintained comparable yields to Vertus but with increasing disease expression. During succeeding years Europe was badly affected by discase and yields were below those achieved by Vertus. Data from other cultivars indicated a positive correlation between symptoms in years 4 and 5, a negative correlation between dry-matter yield in year 5 and symptom severity in year 4, and a negative correlation between symptom severity and yield in year 5. Symptom expression and pathogen build-up appear to occur at similar rates in the latter years of a lucerne crop. Disease development in one season has a considerable effect on future productivity. These findings are discussed in terms of the primary (extra-vascular) and secondary (intra-vascular) determinants of resistance to wilt pathogens. It is suggested that the apparent moderate susceptibility of cv. Europe in seasons two and three relates to a rapid growth rate.
Development of shape in turkey carcasses
Authors: Swatland H. J. 
Published: March 2009

SUMMARYForty-four turkeys including both sexes of two genetic strains were drawn at mean weight-for-age at 2 week intervals from a flock of 380 birds from hatching to 20 weeks post-hatching. Birds were dissected and linear measurements of skeletal units and breast dimensions were compared with keel length using the logarithmic form of Huxley's allometric growth equation. Live weights and weights of selected muscles were similarly compared with breast muscle weight. Wing bones and the biceps brachii muscle grew at approximately the same rate as keel length and breast muscle, respectively. However, leg bones and semitendinosus and gastrocnemius muscles exhibited slower growth than the breast region. Growth of maximum breast length and width was closely matched to keel length but growth in keel depth was much slower. The desirable convexity in breast shape lateral to the keel was considered to be directly proportional to maximum meat depth over the sternum and inversely proportional to keel depth. Maximum meat depth increased at a faster rate than either keel length or depth.
Game domestication for animal production in Kenya: field studies of the body-water turnover of game and livestock
Authors: King J. M. 
Published: March 2009

SUMMARYField studies were made of tritiated water turnover, drinking water and dietary water intake throughout the year, in 212 animals of the following species: African buffalo, dromedary camel, zebu cow, eland, small East African goat, fringe-eared oryx, and Dorper sheep.There were significant differences (P< 0·005) in the water drunk and water turnover between species and between seasons. Furthermore the species (or season) differences were also significantly different (P< 0·005) for each season (or species). The lowest turnover rates were found in oryx, then camel, sheep, goat, eland, cow and buffalo, when expressed in ml/l0·82/day, which was the appropriate metabolic unit for these species.The restraints imposed by traditional African animal husbandry have drastically reduced the natural ability of eland to conserve body water but had much less effect on buffalo and oryx. The reason appears to be that eland is behaviourally adapted to a semi-arid environment, whereas a species like oryx is more physiologically adapted.
Primordium initiation at the shoot apex in four contrasting varieties of spring wheat in response to sowing date
Authors: Stern W. R. , Kirby E. J. M. 
Published: March 2009

SUMMARYThe spring wheat varieties Kolibri, a typical north temperate variety, Pitic 62, a Mexican variety known to respond to vernalization and two selections from the Institute's breeding programme TW 161 and TJB 155 were sown early (2–5 March), during the normal sowing period (27 March) and late (17 April). Primordium initiation was observed until the time of terminal spikelet initiation and the number of leaves and the number of spikelets were analysed in terms of rate and duration of leaf and spikelet primordium initiation. The rate of leaf initiation was affected by time of sowing but not in a systematic way and there were differences between varieties in the way in which the number of leaves changed in response to sowing time. The rate of spikelet initiation increased and the duration decreased with later sowing. There were strong variety × time of sowing interactions. For almost all characters measured, Pitic 62 responded least to time of sowing. Varieties differed in the way in which the number of spikelets per ear responded to time of sowing but in all cases the changes were only small. This waa because the change in the rate of spikelet initiation was almost exactly compensated for by a change in the duration of spikelet initiation. In each variety, the period from terminal spikelet initiation to ear emergence was similar in all sowing treatments and was of similar duration in the main shoot and in the ear-bearing tillers.The number of leaves per shoot on the tillers was less than the number of leaves on the main shoot and the rate of spikelet primordium initiation of the tillers was faster than in the main shoot. These changes tended to synchronize the time of terminal spikelet initiation. Because of the changes in the number of leaves per shoot and the rate of spikelet initiation the number of spikelets borne on the main shoot and the tillers were similar although the growth period of the tillers was shorter than that of the main shoot.