bluuebunny/crossref_metadata_2025 huggingface dataset:
The water consumption of suckling sows
Authors: Garner F. H. , Sanders H. G.
Published: March 2009

The water consumption was determined of thirty-seven Large White suckling sows that were tethered on grass. The mean consumption was 43 lb. a day, the variation between sows, and of particular sows from day to day, being particularly wide. The consumption was practically unaffected by weather and was nearly the same in summer and winter; it was impossible to demonstrate any relation between consumption and number or weight of litter, but there was evidence of a slight decrease as lactation progressed.

It is evident from a brief discussion that exact balance experiments as to the partitions of water for its various uses in the body of the pig are badly needed. It is hoped that the facts given here may draw attention to this point which has been neglected in animal nutrition studies.
The function of the cuticle in relation to the porosity of eggs
Authors: Marshall W. , Cruickshank D. B.
Published: March 2009

1. The porosity of egg is measured by the usual practice of estimating the weight loss under standard conditions. The porosity coefficient is expressed as the loss in weight in mg. per sq. cm. of egg surface per 24 hr. at 37°C.

P coeff.=mg. cm.2 24 hr. 37°.

2. It is shown that eggs of even curvature approximate closely to the ideal mathematical form of two hemi-prolate spheroids, differing in their eccentricities and meeting in the plane of their common minor axes. On this assumption the divergence between the observed and calculated long perimeter is only +0·618 per cent (five eggs) and between the observed and calculated volumes+3·78 per cent (seventy eggs).

3. It is explained how, by taking the specific gravity of the egg to correct for departures from the theoretical form, it is possible to calculate the surface area with an error not exceeding 1 per cent.
The losses of dry matter and digestible nutrients in low-temperature silage, with and without added molasses or mineral acids
Authors: Watson S. J. , Ferguson W. S.
Published: March 2009

A series of experiments designed to measure the losses in dry matter and nutrients in different types of silage are described. These extend over a period of 4 years. The ordinary or low-temperature process (maximum temperature 80–100° F.) is described either with or without added molasses or whey solutions, and is compared with processes in which solutions of mineral acids are added. The A.I.V. process of Virtanen, in which the acidity of the mass is reduced rapidly topH. 3·0–4·0 by the addition of a mineral acid solution, is considered in detail.
The effect of time and rate of application of nitrogen fertilizers on the yield of wheat
Authors: Lewis A. H. , Procter J. , Trevains D.
Published: March 2009

Although it is well known that application of nitrogenous fertilizers to wheat often results in considerable increases in yields of grain and straw, and while experiments at Rothamsted and Cambridge have been very valuable not only in demonstrating the magnitude of the yield increases but also in showing how nitrogenous fertilizers bring about these increases, there is singularly little experimental evidence available regarding the increases in yield which may be expected in other parts of the country. Further, there is very little experimental evidence as to the optimum time of application of nitrogen, except at Rothamsted and Cambridge, both of which are in relatively dry districts.
Terminal ear mutant of maize (Zea mays L.)
Authors: Matthews D. L. , Grogan C. O. , Manchester C. E.
Published: March 2009

A new mutant in maize with an unusual ear location is described. The condition was found to be controlled by a simple recessive gene located near the breakpoint on chromosome 3. The gene symbol, te, is proposed.
The composition and digestibility, when fed to pigs, of three grades of meat meal of widely differing fat content
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

The composition, both organic and inorganic, and the digestibility of three grades of meat meal of widely differing fat content have been investigated. Large White hogs were used in the digestion trials.

The methods of manufacture of the meat meals have been described. They contained, on the basis of dry matter, 18·8, 11·1 and 3·2 per cent of fat respectively.

All three grades had a very high digestibility. The digestion coefficient of the main constituent, namely, the crude protein, ranged from 87·9 per cent in grade C (low fat) to 93·9 per cent in grade B (medium fat), these values comparing satisfactorily with the corresponding value for white fish meal, namely, 90·2 per cent.

The pigs digested the fat of the meat meals very efficiently. The fat of the grade A meat meal, forming 18·8 per cent of the dry matter, was digested to the extent of 95·4 per cent.

The grade B meat meal (medium fat) was the most digestible of the three grades tested. This is the grade that is marketed for feeding to livestock. The slightly lower digestibility of grade A (high fat) is attributed to the influence of the high fat content in causing a slight lowering of the extent to which the crude protein is digested.

The grade C meat meal (low fat) was produced from the grade B by “de-greasing” with petroleum benzine at 300° F. The results suggest that this process may result in a distinct lowering of the digestibility of the meal. The grade C meat meal is the most comparable with white fish meal in both digestible and mineral composition. In comparing the meat meals with white fish meal, however, it must be kept in mind that the former contain a much higher proportion of non-protein nitrogenous material.
Factors affecting the proportions of cross-bred and selfed seed obtained from field bean (Vicia faba L.) crops
Authors: Bond D. A. , Pope M.
Published: March 2009

Winter bean crops, mainly of the variety Throws MS, were surveyed for proportions of cross-bred seed, using hilum colour as a genetic marker. In 1971 a significantly greater proportion of cross-breds was detected in random samples taken from the centre than in similar samples from the border of three fields and from the total of all seven fields. An hypothesis is proposed that pod setting at the centre was limited more than at the border by a factor such as plant competition and chocolate spot at a time when selfing was enforced due to a general lack of bee visitation, or else inbred embryos aborted more under the stress of disease in the centre. No differences between centre and border were found in 1972 except for a greater proportion of cross-breds from the border of a Maris Beagle field and this only applied to parent plants of certain genotypes.

Significant differences were also found between fields and between seasons. There was a significant regression of percentage selfing on field size but there was no evidence that bees failed to penetrate to the centre of large fields.

Implications for variety development, testing and purity are discussed.
The oestrous cycle of the mare following removal of the foetus at various stages of pregnancy
Authors: Day F. T.
Published: March 2009

1. The removal of the foetus between the 51st and 105th day of pregnancy in the mare, did not have any detrimental effect in seven Welsh pony mares.

2. The subsequent oestrous cycles of the mares did not appear to be influenced by the stage of pregnancy at which the foetus was removed.
The quality factor in feeding stuffs
Authors: Murray J. Alan
Published: March 2009

Nutritive values can be resolved into two factors-quantity and quality. The former is represented by the gross energy and the latter by the coefficient of availability (D/T – 0·35), where T is total and D digestible organic matter.

In the natural, vegetable feeding stuffs the gross energy of the total organic matter is practically the same in all cases except those which are peculiarly rich in oil and protein (cakes, etc.). The coefficient may therefore be applied directly to the total organic matter and, subject to a correction in the case of cakes, nutritive values may be expressed in terms of available organic matter (D–0·35T). These terms may be translated into energy values or starch equivalents by simple multiplication.

The method is simple and illuminating. It shows that the nutritive value of the total organic matter depends almost entirely upon its digestibility and, except in the case of cakes, only to a negligible extent upon its chemical composition. Nutritive value is not proportional to digestibility but a linear function of the same, and in substances of low digestibility, slight change in digestibility may cause manifold alteration in nutritive value.
A preliminary investigation of the development of structural constituents in the barley plant (With three text-figures.)
Authors: Norman A. G.
Published: March 2009

1. Barley plants, carefully sampled, were harvested weekly during the season. Growth measurements were made and various analyses carried out on the dried material.

2. Both ash and protein showed an initial increase followed by a steady fall as development proceeded.

3. The Cross and Bevan cellulose fraction, which may be taken as the natural cellulosic fabric of the plant, increased from 30 to 53 per cent., showing an initial peak, and later a stationary period.

4. The amount of cellulosan (or associated polysaccharide) in the cellulose increased with development, and markedly so after the point at which growth increments lessened.1

5. Lignin increased steadily until the last week or so, the fall then probably being due to the increased weight of the grain with respect to the straw.
Seed dormancy and germination in Rottboellia exaltata
Authors: Thomas P. E. L. , Allision J. C. S.
Published: March 2009

Eight laboratory and three field experiments were made on seed of Rottboellia exaltata, a grass weed of maize.

Seed stored dry, indoors or outside, either on the soil surface or buried, was unable to germinate for 5–6 months after being shed. Its ability to germinate then increased rapidly, reaching 50–70% by 8–9 months, and, indoors, continued to increase slowly to reach 80% by about ayear after being shed. Periodic wetting hastened the increase in ability to germinate of seed kept indoors or on the soil surface, but slowed down that of buried seed. When germination was tested with husks removed the ability of the caryopses to germinate began increasing soon after seed was shed, reaching 60% after 3 months and, later, up to 85–95% in different experiments. Dehusking was only effective if the inner bracts as well as the outer husks were removed, but pricking a hole through the husk and inner bracts had an effect similar to removing them. Germination decreased when in-husk seed was immersed in water before being incubated, whether this was done in air or oxygen, or in light or light/darkness, and increased again when seed was dried or its husks pierced before incubation. Wetting and drying in light, but not in darkness, increased germination of in-husk seed, and constant high temperature enhanced the increase.

When seed was buried in soil at a range of depths between 2·5 and 30 cm, the more deeply situated seed remained viable for longer than that near the surface, but there was little viable seed at any depth after 4 years. Many seedlings emerged in the first two rainy seasons after shedding of seed was prevented in an infested field which was ploughed each dry season, but by the third season the number of seedlings had greatly decreased and in the fifth season no seedlings emerged. Most of the seedlings emerging in maize fields came from seeds situated near the surface of the soil.
Investigations into the Intensive System of Grassland Management. By the Agricultural Research Staff of Imperial Chemical Industries, Limited. XI. The Effect of Nitrogen on the Yield, Composition and Digestibility of Grassland Herbage. (With Five Text-figures.)
Authors: Watson S. J. , Procter J. , Ferguson W. S.
Published: March 2009

An experiment was carried out in 1929 and 1930 to obtain a measure of the effects of nitrogenous fertilisers used in combination with rotational grazing, on grass adequately supplied with phosphates, potash and calcium. A comparison of the two years has shown that the magnitude of these effects is governed by climatic conditions, and in the absence of a sufficient supply of moisture the increase in the quantity of herbage produced is reduced.
Regression models to predict herbage production and digestibility in a non-regular sequence of cuts
Authors: Edelsten P. R. , Corrall A. J.
Published: March 2009

Regression models were constructed to predict the yields and digestibilities of herbage cut in different sequences of harvests.

The yield model used a seasonal production curve modified by the effects of defoliation. Values for the model parameters were obtained by fitting the model to experimental data using a non-linear regression procedure. When these parameters were used, to predict treatment effects in another series of experimental data, good agreement was obtained. The digestibility model incorporated the effect on digestibility time of year, regrowth time and yield.

Using the models to interpolate between the results of cutting experiments, annual yields were shown to increase with the date of first cut and also with the interval between subsequent cuts, whereas the average digestibility of the harvested material ecreased with the date of first cut and with the subsequent cutting interval. Finally, a procedure was devised for combining the two models in order to find an optimum cutting strategy for a hypothetical animal production system.
Performance of ewes and lambs on perennial ryegrass, cocksfoot, tall fescue and timothy pastures under upland conditions
Authors: Davies D. A. , Morgan T. E. H.
Published: March 2009

The performance of Welsh Mountain ewes and their single Clun-cross lambs on swards of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.) and timothy (Phleum pratense L.) was studied over 3 years (1975–1977) at a site 305 m O.D. in mid-Wales. Under a rotational grazing regime at a fixed stocking rate of 25 ewes and lambs/ha, mean daily lamb live-weight gain over the 84 days experimental period from early May to late July was 24 g higher on timothy than on perennial ryegrass and tall fescue and 35 g higher than on cocksfoot. Averaged for the 3 years the mean daily lamb live-weight gains were 194, 170, 170 and 159 g on timothy, perennial ryegrass, tall fescue and cocksfoot respectively. There were, however, marked interactions with years.

Ewe live-weight change varied considerably between grasses and years with cocksfoot poorer than timothy and perennial ryegrass. Mean ewe live-weight change ranged from an overall loss of 39 g/day in 1975 to a gain of 34 g/day in 1977.

Differences detected in animal performance between the four grass species altered during the 84 days of the experiment. Timothy and to a lesser extent tall fescue produced better animal performance early in the season whereas perennial ryegrass came into prominence during July.

The results are discussed in relation to the present and potential use of the grass species under upland conditions.
Fattening studies with cross-bred (European×Zebu) bulls: 2. Rate and efficiency of gain on diets of maize residues and concentrate
Authors: Gebrewolde A. , O'Donovan P. B. , Gebremariam H. , Kebede B. , Galal E. S. E.
Published: March 2009

Two fattening experiments are reported with 60 cross-bred bulls. In the first experiment three pen groups (9–16 months old) of eight Simmental, eight Friesian and eight Jersey crosses, from Boran and Barca dams, were fed for 98 days on a common diet consisting of maize cobs, molasses and concentrate. There were no significant differences among sire or dam breeds, with the Barca cross bulls performing non-significantly better than the Boran crosses. Simmentals and Friesians consumed about the same amount of feed and the latter were the most efficient feed converters. In the second experiment, 36 bulls ranging from 11 to 18 months of age were fed for 51 days diets consisting of either 30 or 50% maize stalks and concentrate; maize stalks were replaced by maize/sorghum silage for the next 61 days. There were no significant differences in rate of gain between sire breeds. Bulls from Boran dams gained faster (P < 0·01) than those from Horro dams while a higher (P < 0·05) daily gain was recorded for the diet with the lower than with the higher percentage of maize stalks.
Systematic mixed versus pure stands of wheat genotypes
Authors: Sharma S. N. , Prasad Rajendra
Published: March 2009

A field experiment was made in the wheat growing season (November–April) of 1973–4 at the Indian Agricultural Research Institute, New Delhi, to compare pure and systematic mixed stands of three wheat genotypes differing in plant height. The systematic mixed stands were made to give prismatic and columnar canopy patterns. Grain yield of wheat was significantly greater in the mixed stands than the mean yield in the pure stands; the two mixed stands did not differ significantly. The grain yield in the mixed stands was almost the same or slightly more than that of the largest yielding genotype in its pure stand. When grown in the mixed stand the tall genotype yielded more than in a pure stand but the dwarf genotype yielded less.
Effect of nitrogen fertilizer on growth and yield of semi-dwarf and tall varieties of winter wheat
Authors: Pearman I. , Thomas S. M. , Thorne G. N.
Published: March 2009

Eight amounts of nitrogen ranging from 0 to 210 kg N/ha were applied to two tall and one semi-dwarf variety of winter wheat in the spring of 1975 and 1976. The tall varieties were Cappelle-Desprez and Maris Huntsman; the semi-dwarf variety was Maris Fundin in 1975 and Hobbit in 1976. Interactions between varieties and nitrogen were few and small compared with the main effects. All varieties produced their maximum grain yields with 180 kg N/ha. The yield of the semi-dwarf varieties, but not the others, decreased slightly with more nitrogen.

Cappelle-Desprez yielded less grain than the other varieties in both years. In 1975 the yields of Maris Fundin and Maris Huntsman were similar and in 1976 Hobbit yielded more than Maris Huntsman. The varieties had similar numbers of ears at maturity and similar patterns of tillering. The semi-dwarf varieties had most grains per spikelet, and hence grains per ear, and Cappelle-Desprez had least. The semi-dwarf varieties had the smallest grains. The semi-dwarf varieties had less straw than the other varieties and hence the largest ratios of grain to total above-ground dry weight. The decrease in dry weight of stem and leaves between anthesis and maturity was similar for all varieties. In 1975 the efficiency of the top two leaves plus top internode in producing grain was the same for all varieties, but in 1976 Hobbit was more efficient than the other two. There were some small differences between varieties in nutrient uptake that were not related to differences in growth. Maris Fundin tended to have a greater phosphorus and potassium content than the tall varieties. Hobbit contained slightly less nitrogen than the tall varieties at maturity, and had a smaller concentration of nitrogen in the grain.

Applying 210 kg N/ha doubled grain yield in 1975. Applying nitrogen resulted in a largeincrease in number of ears and a small increase in number of grains per ear due to the development of more fertile spikelets per ear. Nitrogen decreased dry weight per grain, especially of the semi-dwarf varieties. With extra nitrogen, straw dry weight at maturity, shoot dry weight atanthesis and leaf area were all increased relatively more than grain yield, and stems lost moredry weight between anthesis and maturity than without nitrogen. The year 1976 was exceptionallydry and nitrogen had only small effects in that it affected neither straw dry weight nor numberof ears but slightly increased grain yield by increasing the number of spikelets and number of grains per spikelet. It also increased leaf area proportionately to grain yield. In 1975 nitrogen increased evaporation of water from the crop before anthesis but decreased it after anthesis, even though it continued to increase the extraction of water from below 90 cm.
Some effects of the inclusion of leys in a six-course rotation on light land
Authors: Hanley F. , Ridgman W. J. , Allen E. J.
Published: March 2009

An experiment comparing six-course rotations which included 1-, 2- and 3-year leys of pure grass, pure legume and grass/legume mixture is described, and the results from the fifth and sixth phases of the first cycle and first and second phases of the second cycle are discussed.

Compared with all-arable cropping, the inclusion of leys increased the yield of barley grown as the second and third crops after the leys were ploughed up, although the difference was less when 58 kg N/ha had been applied. Neither length nor type of ley affected yield in the second crop after ploughing the leys, but in the third crop 2- and 3-year leys led to greater yield than 1-year leys.

Only rotations containing 1-year leys were compared with all-arable cropping in the fourth and fifth crops after ley, but some effects of these were still apparent in that both Italian ryegrass and broad red clover leys led to an increased sugar percentage of sugar beet grown as the fourth crop when no nitrogen was applied, and broad red clover leys led to a greater response to nitrogen in barley grown as the fifth crop after ley.
American hybrid maize for silage in the south of England Part II. Composition, nutritive value and losses in the silo
Authors: Castle M. E. , Foot A. S. , Rowland S. J.
Published: March 2009

The results are given of an investigation of the successful production, and of the chemical composition and feeding value, of maize silage made from early maturing varieties of hybrid maize grown for three consecutive years in the south of England. The maize was ensiled at a stage when the cob contributed approximately 50% of the total crop and the dry-matter content of the crop varied from 16·3 to 27·2%. The mean crude protein content of the dry matter of the silage was 9·5% (range 7·9–11·2%). Average weight losses in the silo were fresh matter 25%, dry matter 30%, crude protein 25%, and soluble carbohydrates 40%.

In three controlled feeding trials with cows and heifers in milk, maize silage was found to be equal in nutritive value to a ration of mangolds and oat and tare silage when fed on an equal dry-matter basis. The silage was very palatable and a daily ration of 50 lb. was consumed.

It is concluded that although maize silage compares favourably with an average crop of cereal -legume silage in feeding value, its adoption on a wide scale cannot be recommended in view of the relatively low yield of dry matter per acre, the high costs of production and the appreciable silo
Game domestication for animal production in Kenya: prediction of water intake from tritiated water turnover
Authors: King J. M. , Nyamora P. O. , Stanley-Price M. R. , Heath B. R.
Published: March 2009

Five male animals of each of the following species, zebu, eland, small East African goat, fringe-eared oryx and Dorper sheep, were penned, and their water intake measured and metabolic water production estimated. The figures for water input were compared with simultaneous measurements of body-water turnover by liquid scintillation counting of tritiated water in plasma, following dioxane precipitation. It was found that the resultant regression was sufficiently linear with the intercept near zero to justify the use of a ratio to predict input from turnover. The tritiated water turnover overestimated the water input by an amount approximately equal to the overestimate of the body water pool by the tritiated water space. Although there was a considerable amount of variation in individual ratios which could not be explained, there was no significant difference in the mean ratios between species.
Resistance to bean common mosaic virus in dwarf beans (Phaseolus vulgaris L.)
Authors: Walkey D. G. A. , Innes N. L.
Published: March 2009

Numerous dwarf bean accessions were screened for resistance to three strains of bean common mosaic virus (BCMV). Many lines were resistant to a strain of BCMV isolated at Wellesbourne (NVRS) and the Dutch NL4 strain, but only a few lines showed resistance or tolerance to the Dutch NL3 strain. The NVRS strain was found to belong to BCMV Group IVa.

Hybridization experiments showed that resistance to the NVRS strain of BCMV in the dry bean cvs Seafarer and Aurora was controlled by a dominant gene and that in Seafarer this was probably the dominant I gene originally found in Corbett Refugee.
Yield improvement in spring oats
Authors: Lawes D. A.
Published: March 2009

Grain yields of 14 spring oat varieties grown at two levels of nitrogen in three seasons at two locations were compared. A genotype × environment analysis demonstrated that the more recent varieties not only had higher yields but also were better adapted to high-yielding environments. Modern varieties demonstrated a yield improvement of 30% over the older varieties. Examination of components of yield by a series of simple correlations indicated that improvement in varieties by breeding has been associated with shortened straw and higher harvest indices. Within varieties, 1000-grain weight was the most stable character and harvest index the character which varied most consistently with variations in grain yield.
Defoliation studies in hybrid maize: II. Dry-matter accumulation, LAI, silking and yield components
Authors: Singh R. P. , Nair K. P. P.
Published: March 2009

Data are presented from an experiment made in two crop seasons, to examine the effects of plant density and degree of defoliation at different stages of growth in maize at Pantnagar, India, on the dry-matter accumulation in different plant parts, leaf area index (LAI), time of silking and grain yield components.

Different patterns of dry-matter accumulation in various plant parts was observed. Silking was delayed by increasing plant density. Defoliation (even partial) at the 16th fully expanded leaf stage resulted in substantial reduction in LAI and such yield components as number of ears, ear length, ear diameter and 1000-grain weight. On the other hand, partial defoliation done at the 10th fully expanded leaf stage to simulate an ‘erectophile canopy’ led to yield increases even under high plant density (90000 plants/ha) in the Kharif (rainy season), mainly through an increase in number of ears, 1000-grain weight and grain to stover ratio coupled with a reduction in barrenness and percentage of lodging. It is suggested that an increase in the photosynthetic efficiency per unit area of leaf resulting from the ‘erectophile canopy’ is the reason for these effects.
The effect of weaning at 10, 25 or 40 days on the reproductive performance of sows from the first to the fifth parity
Authors: Walker N. , Watt D. , MacLeod A. S. , Johnson C. L. , Boaz T. G. , Calder A. F. C.
Published: March 2009

A total of 146 nulliparous gilts at two centres were assigned to lactation lengths of 10, 25 or 40 days and maintained on the same weaning regime for up to five parities.

The interval between weaning and conception tended to be shorter for the 40-day treatment with little difference between the 10- and 25-day treatments. The data from all parities were pooled on the basis of an assumed herd structure giving the number of litters produced per sow per year aa 2·63, 2·37 and 2·18 for the 10-, 25- and 40-day treatments respectively.

The number of pigs born alive per litter remained more or less static with successive parities on the 10-day treatment but increased on the 40-day treatment with differences between treatment s reaching or approaching significance in parities 4 and 5. Although this trend was reflected in the number of pigs weane d per litter, the differences between lactation treatments were non-significant as a result of higher post-natal mortality in the larger litters of the longer lactating sows.

Consequently sows on the 10-day treatment reared the highest number of pigs per year, 22·4 compared with 20·2 and 19·8 for 25- and 40-day lactations respectively.

Data are also presented on changes in sow live weight.

A high culling rate and an extended interval betwee n weaning and conception were experienced at one centre in parity 1. The possible reasons and effect on subsequent litter size are discussed.
The influence of particle size distribution on soil physical properties
Authors: Towner G. D.
Published: March 2009

Batcombe series soils readily break down to good tilths, Beccles series soils form cloddy seed beds that are resistant to weathering, and Stackyard series soils form unstable tilths that readily break down. The soils differ in their particle-size distribution. The proposition that such differences contributed to the differences in field behaviour was examined by forming artificial soils, each of which was made up from particles of one of the soils, but redistributed with respect to size in the proportion in which they occurred in one of the other soils.

As a measure of the relevant physical properties, breaking strengths and bulk densities of cylindrical ‘clods’ moulded from the artificial soils were determined. To aid interpretation of the observed soil properties, similar measurements were made on individual fractions, on various other mixtures and on the parent soils.

The breaking strengths of the soils made up to a given particle-size distribution from particles from the different parent soils were reasonably close to each other, with those for the Beccles distribution being more variable. There was a significant difference between the two. The strength of the reconstituted Batcombe soil was markedly greater than that of its parent soil, whereas that for Beccles soil was markedly less. There was little difference for the Stackyard soil.

The bulk densities of saturated soils reconstituted from all nine fractions could be estimated reasonably accurately from the properties of the separate components. The structure of each of these soils in the air-dry state was inferred from comparisons between measured and calculated bulk densities. The breaking strengths of air-dry reconstituted soils were estimated from the properties of the separate components, and agreed reasonably well with the measured values for soils in which the clay and fine silt fractions predominated.

Whereas it was generally possible to predict various physical properties of the reconstituted soils from those of the separate fractions, it was not possible to extrapolate the results to explain field behaviour.
A comparison of supplementary sources of nitrogen and energy for increasing the voluntary intake and utilization of barley straw by sheep
Authors: Barry T. N. , Johnstone P. D.
Published: March 2009

Chopped barley straw was fed ad libitum to penned Romney wether sheep. Supplements of urea, ground wheat grain + urea, lucerne hay and autumn saved pasture (ASP) were given for five periods each of 3 weeks using a 5 × 5 Latin square design. The latter three supplements supplied similar amounts of nitrogen and approximately 20% of the energy required for maintenance.

The concentration of ammonia in the rumen fluid of sheep fed the basal straw diet was low and was increased by all the supplements. The concentration of total volatile fatty acids (VFA) in rumen fluid was unaffected by supplementation with urea, but was increased by the three supplements of nitrogen and energy. Differences in VFA molar proportions between treatments were small.

Sheep offered straw alone had a digestible energy (DE) intake of 69% of maintenance and showed a weight loss of 121 g/day. Supplementation with urea had no effect upon apparent energy digestibility (42%) or voluntary intake, but significantly reduced the rate of live-weight loss. The lucerne hay and ASP supplements also had no effect upon straw consumption, but increased total DE intake to 87% of maintenance due to the additional energy provided by the supplements, and reduced live-weight loss. Supplementation with wheat + urea increased the estimated amount of digestible organic matter derived from straw by 8·5%, increasing DE intake to 94% of maintenance and reducing live-weight loss to 18 g/day.

Averaged over all five groups of animals, straw intake increased by 9% in the second period of feeding and then gradually decreased with time, reaching a value in period 5 which was similar to period 1.
Effects of site of seed production on seed yields and regrowth of progeny tubers in potatoes
Authors: O'Brien P. J. , Allen E. J.
Published: March 2009

Nine experiments are reported in which effects of site of seed production on dormancy, sprout and field growth of progeny tubers were recorded. The experiments used early varieties, Home Guard (four experiments), Red Craigs Royal (three experiments) and Arran Comet (two experiments) and in each, seed crops were grown with similar husbandry at sites differing in altitude and location in western England and Wales. There was no consistent effect of site of seed production on the timing of the end of dormancy, and the maximum effect in any year was 11 ± 1·2 (S.E.) days. The small effects of site on dormancy influenced initial sprout lengths, and this effect usually persisted up to planting in Home Guard and Red Craigs Royal, although the effects were small in magnitude. There was no effect of site of seed production on sprout lengths at planting or on field growth and yields in Arran Comet. In the other two varieties there was no effect of site of seed production on yield at early harvests, but at later harvests seed from cooler upland sites sometimes significantly outyielded lowland seed. There was, therefore, no evidence to support the view that locally produced seed was advantageous for early potato production. The results, together with those of the concurrent series with maincrop varieties reported by Wurr (1979), show that on half the occasions on which yields were measured covering the whole of the harvesting period, site of seed production had no effect on yields. In these experiments with early varieties effects of site occurred only at harvests later than the commercial harvesting of such old seed. It is therefore suggested that site of seed production is a much less important determinant of tuber yield than hitherto suggested, and of little practical significance.
Effect of phosphorus and aluminium in the response of spring barley to soil acidity
Authors: Bache B. W. , Ross J. A. M.
Published: March 2009

Soil chemistry in relation to yield of spring barley (Hordeum vulgare, cv. Golden Promise) was investigated in three field experiments in north-east Scotland in 1982. Previous treatments had produced a range of soil pH values from 4·0 to 6·0 (measured in 10mM-CaCl2 solution). The experiments demonstrated the values for soil acidity components below which yields were reduced. Large additions of phosphate fertilizer allowed barley to withstand larger concentrations of soluble and exchangeable aluminium (the principal acid soil toxin), thus decreasing the critical soil pH from 5·2 to 4·8 (corresponding to about 5·9 and 5·5 if measured in a water suspension), and increasing the critical soluble Al concentration from 10 to 50 UM and the critical Al saturation of the cationexchange complex from 0·025 to 0·1.
Effect of sowing date and seed rate on the grain yield and protein content of winter barley
Authors: Conry M. J. , Hegarty A.
Published: March 2009

An experiment, carried out over a 5-year period (1984–88) on medium–heavy textured soil at Athy (Ireland), tested the effect of five sowing dates (early September–early December) and four seed rates (c. 100, 150, 200 and 250 kg/ha) on the grain yield and protein content of winter barley (cv. Panda).

September-sown plots gave the greatest yields in all years. Plots sown in mid-October and later gave significantly reduced yields. Yield reductions over the 5-year period averaged 15, 24 and 34% for the mid-October, November and December sowing dates, respectively. Significant differences in yield between the smaller and larger seed rates were obtained, with the latter giving the greatest yields at all sowing dates from late September to December. Increasing the seed rate, however, did not compensate for the yield reduction due to delayed sowing. In the early September-sown plots, the higher seed rates gave reduced yields in four of the five years (1984–87) with the opposite result in 1988. In 1988 the early September-sown plots gave greater yields than the late September-sown plots.

Regression analysis showed a strong relationship between yield and log(ears/m2) in four of the five years (1984–87) but the relationship was poor in 1988 primarily due to the inexplicably low ear population of the early-sown plots. The inclusion of 1000-grain weight in the model gave a better fit and accounted for a high proportion (62–80%) of the yield variation.

The late September sowing date and the higher seed rates gave slightly lower protein levels in four of the five years. There was an inverse relationship between grain yield and protein for the same four years (1984–87).
Effect of age, abomasal cannulation and rumen catheterization on intake and site of digestion by early-weaned lambs
Authors: Cruickshank G. J. , Poppi D. P. , Sykes A. R. , Familton A. S.
Published: March 2009

The voluntary food intake, in vivo digestibility and site of nutrient digestion was measured in 12 Polled Dorset ram lambs, from 6 to 24 weeks of age, offered clover hay. Lambs were weaned at 6 weeks of age. Six were fitted with a permanent T-shaped cannula in the abomasum and a temporary rumen catheter during the periods of digesta flow measurement.

Surgical modification of lambs did not influence intake (g/kg live weight (W) per day), in vivo digestibility or marker retention time in the rumen. However, intact lambs grew significantly faster than cannulated lambs (139 v. 109g/day, P < 0·05) apparently because of an overall higher cumulative intake over the whole experimental period rather than any change in efficiency of use of nutrients or maintenance requirement.

Relative to live weight, intake increased rapidly until c. 10 weeks of age and remained relatively constant at c. 37 g DM/kg W per day for the remainder of the experiment. Age had no effect on in vivo digestibility of organic matter (OM) or neutral detergent fibre (NDF) (average 0·69).

The proportion of digestible organic matter apparently digested in the rumen (DOMADR) decreased from 0·63 to 0·47 between 8 and 24 weeks of age whilst intake between these measurement periods increased. Nonammonia N (NAN) flow past the abomasum was similar at all ages in relation to digestible organic matter intake (55·1 g NAN/kg DOMI) but was higher at 16 and 24 weeks of age than at 8 and 12 weeks of age, respectively, in relation to organic matter apparently digested in the rumen (OMADR) (116 and 85 g NAN/kg OMADR, respectively, P < 0·05).

Fractional outflow rate of digesta markers from the rumen, when estimated from abomasal digesta, was significantly higher than when estimated from faeces (103Ru-p 0·121 v. 0·09; 51Cr-EDTA 0·169 v. 0·111/h; P > 0·05).

It was concluded that cannulation did not affect intake and digestion characteristics in these young lambs. The changes in the site of nutrient digestion as the animals aged may have been due to agerelated changes in digestive function but appeared to be associated with the increase in intake that occurred between measurement periods of the cannulated lambs.
A new procedure for the continuous measurement of oxygen consumption in pigs
Authors: Giles L. R. , Annison E. F. , Black J. L. , Tucker R. G. , Gooden J. M.
Published: March 2009

Whole-body oxygen (O2) consumption was measured continuously in pigs from the product of blood flow through the pulmonary artery and arterio-venous (AV) difference of blood O2 content across the lungs (pulmonary AV procedure). Blood flow in the pulmonary artery, a measure of cardiac output, was monitored continuously using a transit-time ultrasound flow probe surgically implanted around the artery. The O2 content of pulmonary artery blood, which represents mixed venous blood O2 aturation (SvO2) was recorded continuously by fibre-optic oximetry. The relative constancy of arterial blood oxygen saturation (SaO2), obtained by catheterization of the saphenous artery, obviated the need for continuous monitoring. Complete recovery from surgical procedures, as indicated by the absence of infection and a return to pre-surgery food intake, occurred in 3–5 days. The combination of transit-time ultrasound and fibre-optic oximetry allowed the pulmonary AV procedure to provide continuous data on the oxygen consumption of growing pigs at high temperatures.
The effects of alteration of grain moisture content by wetting or drying on the test weight of four winter wheats
Authors: Pushman Fiona M.
Published: March 2009

The rate of change in the test weight of four winter wheat varieties, with changing grain moisture content, was greater when the grain was wetted than when it was dried. The test weight of grain which had been dried and returned to its original moisture content was lower than that of the original sample.
Effect of ambient temperature and urea supplementation on the intake and digestion of alkali-treated straw by Brahman cattle and swamp buffaloes
Authors: Pearson R. A. , Archibald R. F.
Published: March 2009

Four adult swamp buffaloes (Bubalus bubalis) and four adult Brahman cattle (Bos indicus), maintained in climate rooms, were provided ad libitum with a pelleted NaOH-treated barley straw ration (10·7 g N/kg dry matter) supplemented with sulphur, minerals and vitamins and 0, 14·5 or 22 g urea/kg. The animals were given each diet when housed at 32 °C and, in addition, were given the urea unsupplemented diet at 22 °C. All animals received all treatments for periods of 21 days, measurements being made during the last 8 days, after the animals had been given single doses of two nonabsorbable markers (Cr-fibre and Co-EDTA). Intake, digestibility and gastro-intestinal passage rate were low on the unsupplemented N-deficient (10·7 g N/kg dry matter) diet at both temperatures. Urea supplementation to provide diets of 17·3 and 20·7 g N/kg dry matter was associated with increased intake and digestibility of the feed and increased rate of passage of digesta through the gut.

Despite differences in respiration rate and plasma thyroxine (T4) and triiodothyronine (T3) concentrations at the two temperatures, no effects of temperature on intakes and digestion of the unsupplemented diet were seen. Differences between species were seen in respiration rate at 32 °C and plasma T4, which were higher, and mean retention time of Cr in the gut at 22 °C and water intakes, which were lower, in Brahman cattle than in buffaloes. There were no significant species differences in response to dietary urea supplementation.
Response of rice to rate and time of application of organic materials
Authors: Sharma A. R. , Mittra B. N.
Published: March 2009

Wheat straw (WS), paddy straw (PS), farmyard manure (FYM) and water hyacinth (Eichhornia crassipes) compost (WHC) were applied at four rates and on four dates before transplanting to the rice cultivar Ratna, in a pot experiment at Kharagpur, India in the wet (first crop) and dry (second crop) seasons of 1985/86. Grain yield of the first crop increased significantly with increasing rates of FYM and WHC up to the equivalent of 15 t/ha but, with the application of WS and PS, the yield was greatest at 10 t/ha and decreased at 15 t/ha. On the other hand, yield increased appreciably when WS and PS were applied up to 30 days before transplanting (DBT) but, with FYM and WHC, such increases were less pronounced. The effect of higher rates (10 and 15 t/ha) was more pronounced with early application of organic materials (20 and 30 DBT). Residual soil fertility estimated by organic carbon and available N, P and K increased under all the organic materials, which favourably influenced growth and yield of the second crop grown without supplementary fertilization. The residual effect of increasing rates of WS and PS in increasing grain yield was significantly higher than with FYM and WHC.
Growth, yield and plant-water relations of four cowpea (Vigna unguiculata) cultivars in the Sahel
Authors: Sivakumar M. V. K. , Ntare B. R. , Roberts J. M.
Published: March 2009

The response of four cowpea (Vigna unguiculata(L.) Walp.) cultivars to the warm, semi-arid tropical environment at the ICRISAT Sahelian Center at Sadore, Niger was studied during 1985 and 1986 interms of leaf area index (LAI), dry matter (DM) accumulation, net photosynthesis, stomatal conductance, total water use and yield. Among the three improved cultivars, IT82D–716 is early and erect, cv. IT83S–947 is early and spreading and cv. TVX4659–03E is a medium-duration, highyielding, dual-purpose type. The local cv. Sadore Local is a long-duration, photosensitive, spreading type used mainly for fodder. In both years, Sadore Local recorded the highest LAI. IT82D–716 and IT83S–947 produced < 1·3 t/ha of DM in both years, whereas TVX 4659–03E produced > 2 t/ha of DM and proved superior to Sadore Local in partitioning DM into pods. The four cultivars did not differ significantly either in stomatal conductance or in net phytosynthetic rates. Observed maximum photosynthetic rates of c. 20 μmol/m2/s lie at the bottom of the range 21–38 μmol/m2/s reported for 31 cowpea genotypes in an earlier study. Photosynthetic rates increased with increasing photon flux density. TVX4659–03E had an advantage in total seed plus fodder yields while the local cultivar gave significantly greater fodder yields in both years. Seed and fodder yields, as well as water-use efficiency, confirmed the advantages offered by the dual-purpose cultivar TVX4659–03E. Future breeding efforts in the Sahel should focus on dual-purpose (grain/fodder) cowpea types.
Nitrogen digestion in forage-fed sheep with and without intraruminal propionate infusion
Authors: Seal C. J. , Parker D. S. , Balcells J. , Mole J. L.
Published: March 2009

Nitrogen balance and flow of nitrogen along the gastrointestinal tract were determined in growing wether sheep fed a dried grass pellet diet with or without intraruminal propionic acid infusion. Plasma free amino acid and glucose concentrations tended to be higher in peripheral blood of animals receiving propionate (P < 0·10). Overall total nitrogen and amino acid digestibilities and apparent digestibilities of each fraction along the digestive tract were not affected by infusion of propionic acid. The contribution of microbial amino acids to total amino acid flow in the duodenum measured using purine bases as the microbial marker averaged 0·49 and was not affected by propionic acid infusion. It is suggested that changes in circulating amino acid levels arise from reduced utilization of luminal amino acids by gastrointestinal tissues due to the increased availability of alternative energy-yielding substrates.