bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistical equations for estimating field capacity, wilting point and available water capacity of soils from their saturation percentage
Authors: Dahiya I. S. , Dahiya D. J. , Kuhad M. S. , Karwasra S. P. S. 
Published: March 2009

SummaryStatistical equations were derived for estimating three soil moisture constants, i.e. field capacity (FC), wilting point (WP) and available water capacity (AWC), from soil saturation percentage (SP), which is an easily determinable parameter. The regression equations were evaluated from a data set obtained on 438 soil samples collected from different horizons of 111 profiles of the Indogangetic Plains in northern India, having a wide variation of texture and other physico-chemical properties. The three soil moisture constants were positively correlated with logarithms of SP (r = 0·985 for FC v. In SP, 0·979 for WP v. In SP, and 0·914 for AWC v. In SP). The regression equations were thetested on an independent set of experimental data on 57 samples collected from 14 representative soil profiles of the study area. Values of the three moisture constants of this data set, predicted from the regression equations, were in exceptionally good agreement with the observed values. The mean estimation error (the error of the estimated value relative to the measured value) was only 0·55% for FC, 0·12% for WP and 0·67% for AWC.
Effect of spacing and row orientation on the growth and nitrogen fixation of Azolla and their effects on rice
Authors: Singh A. L. , Singh P. K. , Singh P. L. 
Published: March 2009

SummaryThe intercropping of Azolla pinnata (Vietnam) with rice varieties transplanted in rectangular (40×10 cm) and double-narrow-row (15 × 10:65–80 cm) spacings showed faster growth and nitrogen fixation than in square (20 × 20 cm) spacing with the same number of hills per unit area. Inoculation of 2·0 t/ha fresh Azolla, 10 and 30 days after transplanting, produced Azolla mats on the water surface 25 and 50 days after transplanting, respectively. The total fresh biomass of Azolla grown with different rice varieties in square spacing was 26·7–33·0 t/ha; this produced 41·9–61·3 kg N/ha. However, rectangular and double-narrow-row spacing produced 28·7–37·7 and 34·4–39·6 t/ha fresh Azolla containing 53·9–69·0 and 58·0·73–3 kg N/ha, respectively if the rice rows were transplanted in north-south direction and 36·3–41·5 and 40·0–43·7 t/ha fresh biomass containing 63·4–74·2 and 65·3–83·3 kg N/ha, respectively in east-west direction.The grain and straw yields of rice grown in rectangular and double-narrow-row spacing with north-south row orientation were lower than the yields of rice in square spacing, but the east-west row orientation of these spacings showed yields similar to those obtained by growing rice in square spacing.
Bone growth in the indigenous Nigerian pigs as a function of age, sex and body weight
Authors: Essien A. I. , Fetuga B. L. 
Published: March 2009

SummaryThe left half carcasses of 64 female, 64 castrated male and 64 intact male indigenous Nigerian pigs were dissected in order to study the bone growth between birth and 672 days of age. Total bone weight as well as the weights and lengths of femur, tibia–fibula, humerus and radius–ulna were studied at 16 ages. While bone weights increased between 34 and 45 times from birth to the terminal age range, bone lengths on the average only quadrupled within the same period. Maximum growth in bone weight occurred at 112 days of age whereas bone length attained maximum growth rate at 56 days of age when the body weights had averaged 15·8 and 6·2 kg respectively.Beyond these body weights, the growth rates declined. Although sex differences for total bone weight were not significant, the individual long bones studied exhibited significant sex differences. Highly significant age and sex influences were obtained for the relative bone weights.The growth coefficientsbdetermined for the individual bones and total bone using the logarithmically transformed allometric equationY=oXb, ranged from an average of 0·76 for radius–ulna to O·80 for femur. Pooled values for total carcass bone was 0·84. The values agreed with those reported in literature with side weight as independent variable, and confirm bone to be early developing. Bone lengths were related more to body weight than to chronological age as judged by theR2values. In all the bone traits studied, intact male pigs showed larger values than the castrated male and female pigs.
Muscle growth and development in the indigenous Nigerian pigs as influenced by age, sex and body weight
Authors: Essien A. I. , Fetuga B. L. 
Published: March 2009

SummaryMuscle growth was studied for 64 female, 64 castrated male and 64 intact male indigenous Nigerian pigs at 16 ages between birth and 672 days of age. Highly significant (P< 0·001) age differences were obtained for the proportion of total muscle, each muscle group and the 13 individually dissected (seven hind limb, two spinal column and four fore limb) muscles. Sex differences were significant (P< 0·05) for the proportion of total muscle and some of the individually dissected muscles.A highly significant (P< 0·01) increase in the rate of muscle deposition for each muscle group occurred between 56 and 112 days. Muscle deposition continued at the same rate up till 224 days of age before the peak was attained between 280 and 392 days when the average body weight was between 40·8 and 61·2 kg. A continuously significant (P< 0·05) decline in the rate of muscle deposition was obtained beyond 392 days of age. Growth coefficientsbcalculated from the linearly transformed allometric equation Y = aXbwere generally higher in the early phase of growth (0–168 days) than in later phases considered. However, growth coefficients obtained for the whole period revealed that apart from M. gastrocnemius, the other hind limb and spinal column muscles exhibited either ‘high’ or ‘average’ growth impetus. The fore limb muscles had growth coefficients significantly (P< 0·05) less than 1·00 and were therefore classified as having ‘low’ growth impetus. Generally, the intact male pigs showed superiority to the female and castrated male pigs in muscle growth and development.
Field measurements of the photosynthetic rate of potatoes grown with different amounts of nitrogen fertilizer
Authors: Firman D. M. , Allen E. J. 
Published: March 2009

SummaryThree experiments are reported in which the photosynthetic rates of potatoes grown with various amounts of applied nitrogen (N) fertilizer were measured. Rates of photosynthesis in leaves of plants grown without applied N reached levels as high as those receiving N in all experiments. The rate of photosynthesis in the uppermost leaves of the variety Pentland Crown was found to increase during the season, whereas in Estima rates remained the same. Decline in the rate of photosynthesis with leaf age was more rapid in strongly shaded leaves than in less shaded leaves which were found to be photosynthetically active 8 weeks after expansion.
Efficiency of utilization of energy for egg production in feed-restricted single comb White Leghorn hens
Authors: Degen A. A. , Kam M. , Rosenstrauch A. 
Published: March 2009

SummaryEgg production and body mass changes were measured in six groups, each containing 10 single comb White Leghorn (SCWL) hens, in which each group received decreasing amounts of dry matter (D.M.) in decrements of 10%. Group 1 received 101·2 g D.M./day (100%), an amount normally offered these hens, whereas group 6 received 52·8 g D.M./day (50%). Egg production remained relatively high but body mass declined rapidly in the feed-restricted groups when compared with group 1 in the first 4 weeks (period I); in the second 4 weeks (period II), egg production declined to a great extent but body mass remained constant. Egg production and egg mass were significantly lower in period II than in period I in the feed-restricted birds. In period I egg production did not decrease significantly until the hens were restricted in feed by 30%; in period II this occurred at 20% feed restriction. Energy of eggs produced as a fraction of metabolizable energy intake (MEI) tended to increase in the feed-restricted groups when compared with group I in period I, but decreased significantly at the 40% and 50% group in period II. Maintenance energy requirements for the hens were 569·2 kJ/kg0·75per day and the efficiency of utilization of energy for egg production was 88·2% in period I; these values were 551·6 kJ/kg0·75per day and 74·0%, respectively, in period II. Energy yielded from the catabolism of body tissue per gram body mass loss was 23·08 kJ.It was concluded that the hens initially maintained near-normal egg production at the expense of body energy reserves and then at the expense of egg mass. The efficiency of utilization of energy for egg production was higher when the energy source was mainly from body energy reserves than from MEI (88·2% v. 74·0%). The level of feed restriction and its length of imposition, the body energy reserves of the hen and the source of energy for egg production can explain many of the different responses reported in feed-restricted laying hens. In addition, reduction of 20 to 30 % feed intake in laying hens had little effect on egg production for a short period (4 weeks) during which time the hens mobilized body energy reserves. If these hens were to be sold, then this would add an additional option to this enterprise; that is, reduce feed cost at the expense of body mass prior to the sale of the hens.
Some indices of the carcass composition of Dorset Horn Top Cross lambs. II. Specific gravity as an index of the fat content of the carcass and of various joints
Authors: Khandekar V. N. , McManus W. R. , Goldstone C. L. 
Published: March 2009

An experiment was conducted to investigate the relationship between specific gravity and total fat content of the half-carcass. Specific gravity was found to be highly but negatively correlated with the percentage of fat in the half-carcass(r = −0·9841, P < 0·001).It was also found that the sample joint is a satisfactory index of fatness of joint as well as that of the half-carcass.
Growth curve analysis for treatments-by-environments interaction effects
Authors: Edmondson R. N. 
Published: March 2009

SummaryGrowth curves fitted to factorial data can be modelled using an extrinsic time variate or using the mean responses within the levels of a subset of factors. Where factors can be partitioned into a set of ‘treatment’ factors and a set of ‘environment’ factors, fitting growth curves to the mean effects of environments allows the effects of treatments to be assessed relative to a uniform background growth rate. This leads to a test of a null hypothesis of equal treatment effects in all environments, given that the mean growth rate and stage of development in all environments is equal. The approach is exemplified using data from a glasshouse tomato crop experiment testing variety, nutrient and sowing date factors. Variety and nutrient treatment effects were of direct interest but sowing dates were intended to generalize results by providing a range of growing environments. Treatment effects are analysed by modelling running cumulative yield totals by growth curves and regressing variety and nutrient growth variates on the mean growth variate within each sowing date. In the discussion the case of more than one environmental factor is considered.
The effect of seed rate and nitrogen fertilizer on the yield and nutritive value of oat-vetch mixtures
Authors: Moreira N. 
Published: March 2009

SummaryExperiments were conducted on the seed rates of the components of oat-vetch mixtures combined with varying rates of nitrogen fertilizer in a rainfed area of north-east Portugal in 1982–3 and 1984–5.Forage oats grown alone showed a very high yield response to N and rainfall ranging from 30 to 18·2 t D.M./ha, but had a very low crude protein concentration (37–54 g/kg D.M.) and a poor mineral nutrient composition.The increased use of vetch in the seed mixture had a buffering effect on dry-matter (D.M.) yield but this depended very much on crop N nutrition. For N-deficient conditions vetch inclusion increased the D.M. yield and had a strong positive effect on total forage crude protein (CP) and mineral composition. When crop N nutrition was good, very high D.M. yields (> 12 t D.M./ha) were possible using a high proportion of oats, with vetch making a reduced contribution to the yield and nutritive value of total forage.Seed rates suggested in the literature for Mediterranean conditions are adequate for low N inputs and low available soil N, but not for high D.M. yields which can only be obtained by using a higher proportion of oats and adequate N fertilizer.
A comparison of three laboratory techniques for the estimation of the digestibility of feedstuffs for ruminants
Authors: Omed H. M. , Axford R. F. E. , Chamberlain A. G. , Givens D. I. 
Published: March 2009

SUMMARYThree in vitro methods, one enzymic and two microbial, were applied satisfactorily to the determination of the dry matter digestibility of forages, but failed when applied to a variety of concentrate feeds. The microbial methods had the advantage that the proportion of weight lost from forages during the in vitro process approximated closely with their determined in vivo digestibilities.The microbial method based on sheep faeces was as effective as that using rumen liquor in digesting ruminant feedstuff's in vitro. Since sheep faeces are readily obtained from intact animals, the faeces liquor method would seem to have a distinct advantage in use.
Storage-root weight, diameter and length relationships in carrot (Daucus carota) and red beet (Beta vulgaris)
Authors: Benjamin L. R. , Sutherland R. A. 
Published: March 2009

SUMMARYThe functional relationships between logediameter and logeweight, and between length and diameter of the storage roots in carrot and red beet were described by two linear equations. These equations were fitted to data from three red beet and two carrot experiments. The agreement between the fitted and observed data was close. With increasing plant population density of red beet, the slope of the relationship between length and diameter decreased and the intercept increased. Although these changes in slope and intercept were statistically significant (P< 0·05), their magnitude was of negligible practical importance. The relationship between logediameter and logeweight was little affected by length; the relationship between length and diameter was little affected by logeweight.Using these equations in independent experiments, the diameters of roots of both species were predicted from measured root weights. The roots were then assigned to various commercial diameter grades on the basis of either the measured or the predicted diameter. Except for a few roots of red beet greater than 85 mm in diameter, there was close agreement between the observed and predicted number of roots in each grade.Any model which predicts root weight might be extended to predict yield of marketable size grades, using these equations as a calibration between weight, diameter and length.
Intraspecific variation for frost hardiness in white clover
Authors: Caradus J. R. , Mackay Allison C. , Bosch J. Van Den , Greer D. H. , Wewala G. Sirimathie 
Published: March 2009

SummaryThe frost hardiness of 5-month-old seedlings of 12 white clover cultivars was examined at – 4, – 8, – 12 and – 16°C and in a subsequent study the frost hardiness of 6-month-old seedlings of 190 experimental lines and 23 cultivars and ecotypes was determined at – 12°C. There were large differences among cultivars and lines in frost tolerance based on the percentage of plants damaged and the percentage of leaves killed. The most frost-hardy were the cultivars Podkowa and Undrom and ecotypes collected from Kaikoura and Nelson Lakes. There was no significant, correlation between the percentage germination of cultivars at 4 °C and their subsequent frost hardiness.Large-leaved, erect cultivars tended to be more frost sensitive than small-leaved, prostrate cultivars. Frost-tolerant cultivars and lines tended to be acyanogenic. Selection for low winter growth did not increase frost tolerance. However, lines derived from crosses between genotypes of cold-hardy lines selected for rapid germination at 4 °C were more frost-hardy than lines from genotypes selected in a similar way that had been crossed with unselected Huia genotypes.
Ammonia volatilization from rice fields in alkaline soil as influenced by soil moisture and nitrogen
Authors: Singandhupe R. B. , Rajput R. K. 
Published: March 2009

SummaryVolatilization of ammonia from urea applied to rice on a soil of pH 9·3 was measured during 1982 and 1983 at Karnal. For three moisture regimes (continuous submergence, and irrigation 1 day and 4 days following subsidence of ponded water) mean ammonia losses varied from 28·2 to 31·8 kg N/ha. For urea applications between 40 and 120 kg N/ha, mean ammonia losses varied from 26.1 to 33.7 kg N/ha. Ammonia losses were highest on the second day following urea application and dropped to near zero 7–8 days after application.
The effects of advancing season on the chemical composition of marrow stem kale
Authors: Jones D. J. C. 
Published: March 2009

1. Four varieties of marrow stem kale in the first season, and thirteen in the second, were sampled on three occasions during the first half of the winter. Intervals between samplings were up to 1 month. The plants in the samples were divided into leaf, top half of the stem, and bottom half. The levels of dry matter, proximate constituents and minerals were determined in each sample.2. The differences in composition between the three main fractions of the plant were highly significant for all the chemical constituents, except magnesium. The values for the chemical constituents in the top half of the stem were intermediate between those of the leaf and the bottom half of the stem for most constituents; it had the lowest values for dry matter and the highest for potassium and phosphorus. The distribution of chemical constituents between the whole stem and the leaf were similar to those reported previously.
Fungal growth in silages of sugarbeet press pulp and maize
Authors: Nout M. J. R. , Bouwmeester H. M. , Haaksma J. , Van Dijk H. 
Published: March 2009

SUMMARYFungal spoilage of animal feed silage occurs frequently. In spoiled silage of sugarbeet press pulp sampled in The Netherlands during the period 1986–90, 40% of the samples were infested byPenicillium roquefortii. Other fungi of health significance includedAspergillus fumigatus(8% of all samples) andByssochlamysspp. (4 % of all samples). P.roquefortiiis also the dominant spoilage mould in maize silage. However, no PR-toxin could be detected in 25 lumps of P.roquefortii-intested maize silage, although one lump contained a fluorescent substance, with an Rff-value close to that of PR-toxin. This silage sample was not mutagenic, but had a cytotoxic effect towardsSalmonella typhimuriumin the Ames test. All P.roquefortii-infested lumps contained fluorescent fungal metabolites which were absent in samples taken at 5 cm distance from the corresponding lumps in the silage heaps. It is recommended that lumps of fungal-infested silage are removed before feeding the silage to cattle.
Incorporation of abomasal and intravenous doses of [35S]cystine and [35S]methionine into wool
Authors: Reis P. J. , Tunks D. A. , Sharry L. F. 
Published: March 2009

SummaryThe fate of abomasal and intravenous doses of [35S]cystine and [35S]methionine was investigated in sheep to determine their relative efficacy as supplements for wool growth.Administration of L-[35S]cystine and L-, DL- and D-[35S]methionine via the abomasum produced similar patterns of35S labelling in blood plasma. Only 10–16% of the administered35S was excreted in urine over 7 days and 22–32% of the dose was incorporated into wool over 21 days. All isomers were utilized by the sheep with similar efficiency and it was concluded that D- and L-methionine and L-cystine are equally effective as supplements for wool growth at optimal dose rates. Abomasal supplementation with a large amount of methionine (10 g/day) resulted in the excretion of a high proportion of the35S in urine (55% of the dose over 7 days) and low incorporation into wool.A comparison of the extent of incorporation of35S into wool from intravenous doses of L-[35S]cystine and L-[35S]methionine in the same sheep, and in sheep from flocks selected for high and low wool production, showed that incorporation from methionine averaged 80% of that from cystine. It was concluded that, at moderate (2–3 g/day) methionine availability, methionine is utilized for synthesis of wool with about 80% of the efficiency of cystine, conversion of methionine to cysteine occurring via the transulphuration pathway.
An analysis of the differences in germination of seed lots of perennial ryegrass in response to artificial ageing
Authors: Naylor R. E. L. 
Published: March 2009

SummaryStatistically sound methods for analysing the results of germination tests were used to quantify and assess differences between seed lots of perennial ryegrass (Lolium perenne L.) subjected to accelerated ageing. Ageing altered not only the proportion of seed not germinating but also the mean germination time and the synchrony of germination. Seed lots differed in these three parameters before and after ageing. The responses to ageing of mean germination time and synchrony were not regular and a simulation of trie possible effects of ageing on germination suggested this irregularity might be due to changes in the proportion of viable seeds and to a non-normal distribution of seed ages.
The long-term effects of applying high rates of N fertilizer to winter wheat
Authors: Holbrook J. R. , Ridgman W. J. 
Published: March 2009

SummaryAn experiment in which all combinations of four rates of N fertilizer soon after sowing, four in early spring and nine in late spring were applied to the same plots of winter wheat for 6 years is described and the effects discussed.It was found that although the yield varied considerably from year to year the regime leading to greatest yield was fairly consistent. If the farmer had used the regime which gave the greatest average yield (0, 90, 180 kg N/ha in autumn, early spring and late spring, respectively) he would have averaged only 0·12 t/ha less than the maximum attainable each year.Application of N increased protein concentration in the grain more or less linearly but the latest application increased it most. Since the regime which gave greatest yield on average produced grain which qualified for bread-making premium from the protein point of view in all years except 1981, adopting the regime which gave maximum yield would reduce the potential maximum gross margin by only £30/ha.Analysis of the soil showed a reduction in pH down to 15 cm and of available P2O5 down to 10 cm.