bluuebunny/crossref_metadata_2025 huggingface dataset:
An examination of the net changes in amino-acid composition within the rumen of mature wether sheep using canonical variate analysis
Authors: Fenlon J. S. , Beever D. E.
Published: March 2009

Data for the quantity of ammo acids consumed and their flow rates at the proximal duodenum for 33 diets fed to sheep have been statistically analysed by both univariate and multivariate methods. Analysis of variance of net loss (g/day) between mouth and duodenum of individual and total acida was not conclusive. Canonical variate analysis which takes regard of the correlations between different acids both within and between diets provided a conoise method of discriminating between diets. The advantage of this method in generating a unified account of digestion within the rumen is that it effectively reduces the problem from one of many dimensions to a situation where only the first few transformed variables need to be considered.
Winter leaching of nitrate from autumn-applied calcium nitrate, ammonium sulphate, urea and sulphur-coated urea in bare soil
Authors: Addiscott T. M. , Cox D.
Published: March 2009

In a flinty clay loam at Rothamsted, nitrate concentrations in 0–13 and 13–26 cm layers of plots given all N-sources at 100 kgN/ha in early October were very small by mid-January. Incorporating the fertilizer in the first 13 cm slightly accelerated this loss. Sulphur-coated urea (SCU) maintained smaller nitrate concentrations than other sources in both layers. By early March SCU plots alone had slightly larger nitrate concentrations than the controls in the 0–26 cm layer, whilst in the 26–52 cm layer all N plots had slightly larger concentrations than the controls. Spring barley, given no more N and harvested green at ear emergence, took more N from all N plots than from the controls, most from ammonium sulphate and least from urea and SCU, but differenoes between sources were not significant. The nitrate loss had a negligible effect on soil pH and exchangeable cations.

Calcium nitrate leaching data were used to test the equation of Burns (1975) and other simple equations which considered the effects of successive percolations in a two-layer system assuming that the layers either could or could not become temporarily oversaturated. All the equations underestimated leaching unless the most inaccessible soil water was left out of the calculations and gave best results when only gravitational water was taken into acoount.
Quantitative digestion of fresh herbage by sheep
Authors: Egan A. R. , Ulyatt M. J.
Published: March 2009

The utilization by sheep of dietary N provided in high protein, high water content fresh herbages (Ruanui perennial ryegrass, Tama Westerwolds ryegrass, Pitau white clover, and Fakir giant sainfoin at two stages of maturity) was studied at two levels of intake (maintenance and 1·5 maintenance). Feed was provided by constant feeder.

Apparent digestibility of N was similar for all herbages (ca. 85%) except sainfoin which, particularly at a late stage of maturity, was lower (70–80%). A small loss of nitrogen across the stomachs occurred with clover (1–3 g/day) and Tama ryegrass at the higher feeding level (2 g/day), but no loss was observed with the other diets. The apparent digestibility of N and of non-ammonia N (NAN) in the intestines was lower for sainfoin, and estimated true digestibility was also lower. Amino acid N contributed less to the NAN reaching the duodenum on the sainfoin diets than on the grass and clover diets.

N retention was negative at the lower level of feeding for ryegrass and clover diets. It was greatest for the sainfoin diets at similar N intakes, so that efficiency of retention of apparently digested N was also greatest for sainfoin.

The size of the urea pool, the plasma urea concentration and the urea irreversible loss, using [14C]urea, did not differ significantly between diets at similar N intake. Urea irreversible loss exceeded urinary urea excretion by 35—50% on all but the late-maturity sainfoin diet, where urea irreversible loss was more than double the urinary urea output. These data indicate dietary differences in the extent of degradation of urea on recycling to the gastro-intestinal tract. Urea clearance across the kidney was also lowest for sainfoin.

Data are compared in a simple model which illustrates the importance of variable clearance of urea across the kidney and the gut wall and the need for knowledge of factors which control this.
The effect of host development on the field assessment of disease resistance to Cercospora leaf spots in groundnuts (Arachis hypogaea L.)
Authors: Nevill D. J. , Evans Alice M.
Published: March 2009

In previous studies of the reactions of groundnut varieties to infection with Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & Curt.) Deighton, the existence of disease resistance has been demonstrated. However, these investigations have not resulted in the production of high yielding, disease resistant, varieties and it has been suggested that disease resistance is physiologically linked to low seed yield. In the present study, two aspects of the host–pathogen interaction were investigated: these were varietal response to chemical disease control, and the effect of plant sterility on host and pathogen development. It was found that a general score of resistance to leaf spot did not always relate to the varietal response to disease control and reasons for this were proposed. The prevention of pod production did not affect pathogen development, but vegetative growth of the treated plants was increased. It was concluded that host and pathogen development could be confounded during the assessment of disease resistance. In future varietal screening trials, the use of single branch comparisons should prevent this confusion.
Changes in the water status of tea clones during dry weather in Kenya
Authors: Carr M. K. V.
Published: March 2009

Partial closure of the stomata occurred during the middle of the day even when tea plants were growing in a wet soil and there were similar diurnal changes in the xylem water potential (ψx). As the soil dried the daily minimum values of ψxdeclined, more in some clones than in others, and there were also interesting differences between clones in the sensitivity of their stomata to changes in ψx. Possible ways in which these observations could form the basis of tests for screening clones for drought resistance are discussed.
A simple technique for the short-term storage of pollen of a dihaploid-inducing diploid potato clone
Authors: De Maine M. J.
Published: March 2009

Two methods of storing pollen of the dihaploid-inducing Dutch (Wageningen) Solatum phureja clone, IVP 48, are described. Pollination results showed that the functional fertility of one type of stored pollen is similar to that of fresh pollen when used in dihaploid induction crosses on tetraploid potatoes. No obvious relationship was found between the in vitro germination of the pollen samples and their functional fertilities in dihaploid induction crosses.
Development of body components in Kenana cattle. 2. Relative weight changes of major carcass tissues
Authors: Gaili E. S. E. , Nour A. F. Y. M.
Published: March 2009

Thirty-two weaned Kenana bull calves were adequately fed to maximize growth and serially slaughtered at predetermined live weights of 100, 200, 300 and 400 kg. Eight animals were slaughtered at each slaughter point and the left side of each carcass dissected into individual muscles, bone, fat, tendons and fascia. Individual muscles were grouped into nine muscle groups and the distribution of intermuscular fat was studied in four anatomical regions. Huxley's (1932) allometric equation was used to describe the development of carcass tissues.

Relative to overall carcass side growth, fat was the fastest developing tissue, followed by muscle and bone tissues in descending order. The muscles of neck + thorax and abdominal muscles exhibited the fastest rate of growth relative to overall total side muscle growth, and the distal muscles of both limbs exhibited the slowest rate of relative growth. Relative to the rate of side fat deposition throughout the experiment, subcutaneous fat was deposited at a faster rate than intermuscular or kidney + channel fat. Intermuscular fat was deposited at different rates in the anatomical regions of the carcass.

The development of muscle groups was further examined in three arbitrary phases of the test period and revealed significant differences between phases in the rate at which each muscle group developed. Similar changes in the intensity of the rate at which fat was deposited in the subcutaneous region and between the muscles of the carcass or sites were evident.

Kenana cattle compare favourably with foreign dairy and beef breeds of cattle in muscle:bone ratio. Further studies are needed to evaluate the efficiency of meat production from Kenana cattle under different systems of management.

As reported in Part 1 (Gaili & Nour, 1980) a study was conducted to investigate the development of body components in Kenana cattle and to evaluate the potential of the breed for meat production. This paper is an account of the data which were obtained on the development of carcass tissues.
An index of feather cover
Authors: Macleod G. D. , Clark J. A.
Published: March 2009

An index of feather cover is described and applied to assess the coats of various birds. Feather area indices were calculated, by analogy with the leaf area index used by crop ecologists, as the projected area of feathers above unit area of skin. Measurements were made on samples from chickens, turkeys, pheasants, sparrows and herring gulls. The index was calculated for feather tracts on six areas of the body. An overall area index was also calculated, based on the feather cover of at least 60% of the bird's body surface. Intra- and interspecific differences were large. Between species there was a positive correlation between feather index and body weight, while within species, for poultry at least, the opposite was found. This characterization of the feather coat is discussed in terms of its possible use as an index of the insulation of feathers.
Response of wheat to zinc and its critical level in Old Alluvium soils
Authors: Singh A. P. , Sakal R. , Thakur K. N. , Sinha H.
Published: March 2009

A pot culture experiment with 30 Old Alluvium soils was conducted to evaluate the critical Zn concentration in soils and wheat plants for predicting the response to Zn application. The DTPA-extractable Zn (available Zn) in these soils ranged from 0·37 to 4·50 mg/kg soil, and total Zn in the wheat plants of the control pots ranged from 17 to 65 mg/kg wheat shoots. The DTPA-extractable Zn was found to be positively correlated with organic carbon (r = 0·72, P < 0·01), negatively with pH (r = –0·48, P < 0·01) and positively with wheat tissue Zn concentration (r = 0·98, P < 0·01). The Bray's ‘per cent’ yield value was positively correlated with ‘available’ Zn (r = 0·82, P < 0·01) and plant tissue Zn (r = 0·85, P < 0·01). The critical concentration of Zn in soil and plant below which responses to applied Zn may be expected was 0·65 mg Zn/kg soil and 24·5 mg Zn/kg wheat shoots respectively. All the soils below 0·65 mg Zn/kg soil responded to Zn application where the ‘per cent’ response at 5mg added Zn/kg soil ranged from 22·65 to 100·00 with a mean value of 58·24 whereas at 10 mg added Zn/kg soil, it ranged from 13·08 to 97·14 with a mean value of 40·08. Soils above the critical limit negatively responded to Zn application.
Relative efficiency of rock phosphate and superphosphate for forage legumes and residual effects on succeeding wheat
Authors: Prasad R. , Singh A.
Published: March 2009

A field experiment was made at the Indian Agricultural Research Institute, New Delhi to compare the efficiency of Mussoorie rock phosphate with ordinary superphosphate for two forage legumes, cowpea (Vigna sinensis Savi) and cluster beans (Cyamopsis tetragononoloba L.) and residual effects were studied in wheat (Triticum aestivum L.). For both the forage legumes Mussoorie rock phosphate was only 22% as effective as ordinary superphosphate (on soil of pH 7·1) and it had no significant residual effects on wheat even when the application rates supplied three times as much P as was supplied by ordinary superphosphate.
Analysis of ergots from winter wheat in northern Scotland
Authors: Osborne B. G. , Watson R. D.
Published: March 2009

Ergots are the sclerotia of Claviceps purpurea (Fr.) Tul., which periodically infects certain cereals especially wheat and rye, and frequently infects numerous grasses (Mantle, 1977a). The ergots are produced in the seeding heads of the plant and are harvested with, and thus contaminate, the grain, causing the mycotoxicosis known as ‘ergotism’ in livestock fed contaminated cereals, or in humans eating bread made from contaminated flour (Mantle, 19776). The disease is caused by certain alkaloid constituents of the ergots which are derived from lysergic acid. Symptoms in humans are hallucinations, convulsions, gangrene of the limbs and other extremities, and eventually death. Seven isomeric pairs of indole alkaloids have been isolated from ergot, ergocristine and ergocristinine, ergotamine and ergotaminine, ergocryptine and ergocryptinine, ergocornine and ergocorninine, ergosine and ergosinine, ergostine and ergostinine, and ergometrine and ergometrinine. The first named of each pair is derived from lysergic acid and is physiologically active, while the second is derived from isolysergic acid and has little physiological activity.
The cultivation of maize for fodder and ensilage Part II. The effect of changes in plant density
Authors: Bunting E. S. , Willey L. A.
Published: March 2009

The evidence from these combined variety × plant density experiments, together with the additional data on varieties previously reported (Bunting & Willey, 1958), suggests that, for fodder or ensilage production in Britain, the varieties we have designated as ‘medium’ (i.e. within the range represented by the hybrids Wis. 275 and Wis. 341 A), sown to give a final density of 9–12 plants/sq.yd. would be most suitable. Higher plant populations probably give slightly higher yields, but the differences will rarely be of practical importance and are likely to be offset by the greater incidence of lodging and the consequent increase in harvesting difficulties.
Experiments on the nutrition of the growing dairy heifer. III. Effects of air temperature and live weight on water consumption
Authors: Bailey G. L. , Broster W. H.
Published: March 2009

The effects of air temperature (30–70° F.) and live weight upon the water consumption of dairy heifers from 350 to 550 lb. live weight have been studied together with the amount drunk in different periods of the day. The water consumption increased by 0·03–0·06 gal./° F. rise in temperature and by 0·0075 gal./lb. increase in live weight. Most of the water consumption occurred during meals.
Feeding trials with ammoniated molasses in the diet of young dairy cattle
Authors: Bartlett S. , Broster W. H.
Published: March 2009

1. Ammoniated invert molasses when used as a food for yearling dairy cattle proved toxic in doses of 1 lb. per day.

2. When ammoniated invert molasses had been acidified with phosphoric acid the toxicity was markedly reduced but not entirely eliminated. Ammoniated molasses acidified with acetic acid produced no toxic effects but the live-weight responses of yearling cattle was inferior to a ration markedly deficient in protein. The poor responses may have been partially due to the unpalatability of the ammoniated molasses.

3. The ammoniated molasses used in experiment 1 did not produce toxic symptoms in rats but it did result in reduced food consumption and poor growth.

4. The ammoniated molasses treated with acetic acid, when included at the rate of 10% of the diet of guinea-pigs, depressed appetite and caused toxic effects.
Utilization of low quality roughages: effects of alkali treatment of wheat straw on intake by and growth rate of cattle, with and without a supplement of cotton-seed meal
Authors: Sriskandarajah N. , Kellaway R. C.
Published: March 2009

Effects of treating wheat straw with caustic soda solution and of providing a cottonseed meal supplement were studied with 40 Friesian heifers (280 kg live weight) in individual pens. Responses were measured in terms of food intake, growth rate and food conversion ratio.

Wheat straw was coarsely-milled and fedad libitum, untreated (U) or alkali-treated (T); both types of straw were supplemented with urea and minerals. Half the animals on each type of straw were fed 500 g cotton-seed meal (C/day.

Straw intake was higher with T than with U (P< 0·01) and unaffected by the cotton-seed meal supplement, being 4·53, 4·71, 6·58 and 6·56 kg/day on treatments U, UC, T and TC respectively. Alkali treatment and the cotton-seed meal supplement improved live-weight change (P< 0·001), being –6, 189, 334 and 495 g/day respectively.In vivodigestible organic matter in the dry matter, calculated from lignin ratios, was 59, 60, 64 and 64 respectively.

Rumen VFA concentrations were significantly higher, molar proportions of acetic acid lower, propionic andn-butyrie acids higher in animals on T than on U. Plasma urea and rumen ammonia concentrations were lower on treatment T than on U.

It was concluded that wheat straw which is coarsely-milled, NaOH-treated and sprayed with urea and minerals provides sufficient nutrients to allow cattle to grow and that additional gain obtained by feeding cotton-seed meal was predictable in terms of its energy contribution to the diet.
The phosphorus requirements for growth and maintenance of sheep
Authors: Field A. C. , Coop R. L. , Dingwall R. A. , Munro C. S.
Published: March 2009

Phosphorus requirements for maintenance and growth were assessed by giving to growing lambs and non-pregnant ewes diets low in P and to growing lambs a diet containing the quantity of P recommended by the Agricultural Research Council (1980).

Seven 14-week-old lambs were given ad libitum a pelleted diet containing 1·88 (LP) or 2·75 (NP) g P/kg D. M. for 13 weeks. There was no effect of P intake on feed intake or growth during the first 8 weeks when the P intake of the LP groups was 1·07 of Agricultural Research Council (1980) requirements. During the last 5 weeks the P intake of the LP group was only 0·87 of Agricultural Research Council (1980) requirements and growth and feed intake were higher in the male but not female lambs in the NP group. From the 3rd week the plasma concentration of P was significantly lower (P <0·001) in the LP group. Mineralization of selected bones was less in the LP group.

After 14 weeks on the diet, balance trials with 32 P were carried out on the lambs from each dietary group. P intakes ranged from 1 to 3 g/day. An additional balance trial was undertaken with eight 2-year-old female sheep consuming a hay diet (1·5 g P/day).

The endogenous faecal excretion of P by the growing lambs on the LP diet and ewes was 12·2 ± 0·8 and 12·7 ± 1·00 mg/kg live weight/day respectively, very close to the value (12 mg/kg live weight/day) adopted by the Agricultural Research Council (1980). The absorbability of the P in the concentrate and hay diets was 0.71 ±0·267 and 0·74 ± 0·0218 respectively, the former agreeing with and the latter higher than the corresponding value for Agricultural Research Council (1980).
The permanence of organic matter added to soil
Authors: Mann Harold H. , Barnes T. W.
Published: March 2009

The rate at which organic matter added to soils decomposes under temperate conditions seems to have been little studied. It depends, as Russell (1950) remarks, on the soil aeration, the calcium supply, and the temperature, and tends, in an arable soil, to an equilibrium value depending on the crop rotation practised for a given soil under given climatic conditions. And while this equilibrium value is lowest for a rotation containing a high proportion of wide-spaced intertilled crops or cultivated fallows, it increases with crops of small grains or grass. The results at Rothamsted, Broadbalk Field, as judged by the nitrogen content, show that this equilibrium value with no organic additions has remained almost constant from 1865 to 1945 and similarly, at a higher level, where 14 tons of farmyard manure are applied annually, has remained constant from 1914 to 1945.
Measurement of feed intake of grazing sheep: I. Rate of passage of inert reference materials through the ruminant digestive tract
Authors: Lambourne L. J.
Published: March 2009

Experiments are described which give some basic information on the rate and pattern of marker excretion by sheep on pastures ranging in digestibility from 70 to 80% and on hay of barely 50% digestibility.

The faeces output of individual sheep varied from 100 g. to more than 400 g. daily, and the estimated feed intake from below 400 to over 1,900 g. daily.

Despite these wide ranges a typical pattern for the passage of single doses of markers was quite consistently repeated in the trials on pastures:

1. Markers first appeared in the faeces 5–8 hr. after dosing.

2. Concentrations rose rapidly to peak values about 10–18 hr. after dosing.

3. Concentrations fell thereafter by about 50% each 6–10 hr. until 60–70 hr. after dosing when marker content could no longer reliably be determined by the methods used.

Factors affecting the basic pattern

1. The overall quality of the feed was of prime importance, in that peak concentrations occurred progressively later on poorer pastures and on hay.

2. For any given feed a high level of (estimated) feed intake was often associated with earlier appearance of marker in the faeces, an earlier peak of concentration, and slightly faster fall in marker concentration.

3. There was evidence that the time of administration might slightly affect rate of passage, presumably through its relation to grazing periods, for doses given at or near times of greatest feed intake were passed rather more rapidly.

4. It did not appear that there was any considerable retention of either marker within the tract beyond 72–96 hr. after dosing.
The adaptation of energy utilization in the laying hen to warm and cool ambient temperatures
Authors: Davis R. H. , Hassan O. E. M. , Sykes A. H.
Published: March 2009

Two experiments have been performed to study the acclimatization of laying hens to cool or warm environmental temperature, using the comparative slaughter procedure to measure energy utilization. In the first experiment the energy balances over a 3-week period at either 10 or 35 °C were compared; in the second experiment a comparison was made of the energy balances over six consecutive weekly periods at similar cool and warm temperatures.

The first experiment confirmed that production could be maintained (88%) in the warm environment even though food intake was markedly reduced (95 and 63 g/day at 10 and 35 °C respectively). In both environments a loss of body weight indicated, that energy intake was insufficient to meet demands for at least part of the period.

During the first week of the second experiment there was a small loss of body weight in the cool environment and food consumption was slightly depressed. The results for energy intake, egg production and heat production suggest that acclimatization was complete after 1 week. In the warm environment egg production fell initially (62%) but returned to a high level (86%) during the second week. However, energy intake, body weight and heat production did not reach steady levels until the fourth week. Comparing the first 3 weeks with the subsequent 3 weeks the daily ME consumption was 137 and 161 kcal/kg¾ and the daily heat production was 126 and 116 kcal/kg¾. Similar, although less marked differences were observed in the cool environment. These results therefore emphasize the need to allow adequate time for acclimatization to the environment in studies of energy metabolism.
Epidemiology of Phytophthora capsici on bell pepper
Authors: Schlub R. L.
Published: March 2009

The number of pepper seedlings (Capsicum annuum L.) surviving transplanting in a glasshouse decreased from 100% in the control to 84 ± 6,55 ± 8, and 18 ± 6% in field soil containing 1, 5 and 25 propagules of Phytophthora capsici Leonian per gram soil, respectively. When detached leaves were inoculated with a sporangial suspension at 15 and 31 °C, an incubation period of 24 h was required before an infection level of 50% was reached. Incubation at 27 °C for 4 h resulted in 60% of the leaves infected. Neither sporangia nor mycelia survived a week in leaf tissue if the relative humidity was 47% or less or if the temperature was -12 or 40 °C. Recovery of sporangia from inoculated stem pieces (2 cm long) stored for 1 week at 25 °C was reduced from 1455 to 30 sporangia per stem piece when the relative humidity was reduced from 100 to 87%. P. capsici could not be isolated from inoculated leaf tissue 2 days after being placed on the soil surface in a field, but was easily isolated after 14 days if buried. The distribution of disease within a test field followed the field's drainage pattern. Splashing rain and run-off water appear to be the main means of spread. Combined rainfall for days 3, 4, 5 and 6 prior to symptom development correlated with disease incidence (r = 0·53, P < 0·01).
Effect of P and Zn addition on maize grown on calcareous soils
Authors: Nychas A. , Skarlou V.
Published: March 2009

Nutritional problems for cultivated plants related to phosphorus (P) and zinc (Zn), among other elements, are common in recent alluvial calcareous soils of Greece. The negative interaction which exists between these two elements aggravates these problems.
Quality tests on hen eggs produced in laying batteries and in fold units
Authors: Walker D. M. , Offord E. C.
Published: March 2009

1. Two groups of Rhode Island Red × Light Sussex pullets were housed respectively in batteries and in a fold unit.

2. Samples of the eggs produced were collected monthly and weights of egg fractions, quality tests on yolk and thick white, and porosity coefficients were determined.

3. The tests were continued for a 9-month period and no consistent differences were found in the quality of the eggs produced under the two systems of housing.

4. Colours of yolks produced by battery pullets were paler than those produced in the fold unit on grass. Yolk colour was improved by increasing the proportion of grass meal in the diet of battery birds.
Identification of phyto-oestrogens in berseem clover (Trifolium alexandrinum)
Authors: Shemesh M. , Ayalon N. , Lindner H. R.
Published: March 2009

The oestrogenic isoflavones genistein, biochanin-A and formononetin, as well as the coumestan derivative coumestrol, were identified by thin-layer, paper and gas chromatography in berseem clover (Trifolium alexandrinum) grown in Israel. Under the conditions studied, the concentration of these oestrogens in the berseem clover (total < 0·01% in the dry matter) was considerably lower than those found in clover species known to be associated with infertility in ruminants.
A study on the pollination mechanism in field beans (Vicia faba L.)
Authors: Kambal A. E. , Bond D. A. , Toynbee-Clarke Gillian
Published: March 2009

Inbred lines and hybrids of English tick and horse beans and exotic stocks were studied with respect to pod set, floral structure and pollen production and germination to find out why most inbred lines set few or no seeds without tripping whereas most hybrids and some inbred lines set equally well with or without tripping. The most important outcome was new information on variation between genotypes in flower structure and pollen quantity and on how these two characters affect the mechanics of self-pollination. Though heterosis in terms of abundant pollen production could be a factor in the self-pollinating ability of hybrids, some of the inbred lines were capable of self pollination despite limited pollen production, because the structure of the flower permitted the pollen to reach the stigma via a short route. The floral features associated with the ability to self-pollinate in the inbred lines included a relatively short style bending at more or less a right angle, few and short stylar hairs and stigmatic papillae, and less pronounced ridges on the inside of the keel petals. The implications of these findings to the development of self-pollin ated varieties of field beans are briefly discussed.
Nitrogen requirement of sugar beet in relation to irrigation
Authors: Holmes M. R. J. , Whitear J. D.
Published: March 2009

Three field experiments were carried out on sandy loam soil at Levington, Suffolk, on the effect of irrigation on nitrogen requirements of sugar beet. Four nitrogen rates (0, 67, 134, 201 kg/ha) were examined with and without irrigation. Nitrogen increased sugar yield each year, as did irrigation in 1969 and 1970, but not in 1968 when the soil moisture deficit was small. There was a significant nitrogen x irrigation interaction in 1970 only, but on average there was a greater response to nitrogen with irrigation than without it.

These results and other published data suggest that on sandy soils in eastern England moisture deficit can restrict nitrogen response, and that the economic optimum nitrogen rate is appreciably higher with irrigation than without it.
Selection for developmental responses in winter barley
Authors: Jenkins G. , Kirby E. J. M. , Roffey A. P.
Published: March 2009

A winter barley variety, from the USSR, 13031, lacking vernalization requirement but sensitive to short days and more frost resistant than varieties now commercially grown in Britain, was hybridized with Shimabara, a Japanese variety which requires vernalization but is less sensitive to short days and more susceptible to frost than 13031. The resulting segregating population was then selected under short days and non-vernalizing conditions and in artificial freezing tests, in order to isolate recombinant lines.

Five lines derived in this way, together with the parents and the standard winter barley variety, Maris Otter, were included in a detailed developmental study made in a glasshouse under cool, short days.

Four of the lines had very similar developmental characters, namely few leaves and a high rate but short duration of spikelet initiation. Developmentally these selections resembled the parent Shimabara more closely than 13031 but the rate of spikelet initiation was faster than that of either parent and the duration of spikelet initiation was shorter. The fifth selection also resembled Shimabara more closely than 13031 but had more leaves and a lower rate and longer duration of spikelet initiation than the other selections. This selection was found to have a strong vernalization requirement.

One selection closely resembled 13031 in its frost resistance but had low short-day sensitivity and no detectable vernalization requirement. The complementary characters of the two parents were therefore recombined in this line.

Vernalization had little effect on the development of any of the genotypes under cool, short days in a glasshouse.
Efficiency of Mussoorie rock phosphate as a source of fertilizer phosphorus to guar (Cyamopsis tetragonaloba) and groundnut (Arachis hypogaea)
Authors: Hundal H. S. , Sekhon G. S.
Published: March 2009

In two field experiments, Mussoorie rock phosphate with or without pyrite, farmyard manure or straw was compared with concentrated superphosphate when applied to guar and groundnut. The treatments included rates of 10, 20 and 30 kg P/ha and were located on a soil low in available phosphorus.

Mussoorie rock phosphate was 44–52% as efficient as concentrated superphosphate. The incorporation of Amjhore pyrite, farmyard manure or straw in the soil with rock phosphate increased the effectiveness of Mussoorie rock phosphate.

Extractability coefficient ratios obtained upon laboratory incubation of soil with concentrated superphosphate and rock phosphate correlated fairly well with the availability coefficient ratios obtained from measurements with plants in the field experiments.
Effect of sink size on the pod and seed characteristics of soya beans (Glycine max (L.) Merr.) in the lowland tropics
Authors: Tayo T. O.
Published: March 2009

The size of the sink on two indeterminate (cv. Hampton and cv. TGM 119) and two determinate (cv. Bossier and cv. TGM 294) cultivars of soya beans were reduced by continuously limiting the number of pods developing at each fruiting node to either one or two, starting from 2 weeks after anthesis, in three field experiments (early 1980, late 1980 and early 1981). Thiswas in order to evaluate the effects of sink size on the development of pod and seed characteristics as well as to quantify the inter-relationships between these characters under humid tropical conditions.

Persistently reducing the number of pods developing at each fruiting node consistently significantly reduced the number of pods per plant, the pod and seed dry weights per plant, the total number of seeds per plant and the harvest index (seed weight as a proportion of total dry weight) in all cultivars when compared with the control. On the other hand, the treated plants of all cultivars generally had longer pods, heavier individual pods and seeds, more seeds per podand greater leaf area and leaf dry weight as well as greater specific leaf weight than the control plants. Compensation indices (percentage increases in size over control) were 25–30% for weight per pod and seed weight per pod; 11–16% for weight per seed and number of seeds per pod and 2–5% for pod length in the treated plants.

Most of the characters measured (except individual weight of pods and seeds, seed weight per pod and number of seeds per pod) had significant interaction effects of sink size, cultivar and season; season had the highest correlation ratio, followed by cultivar, and sink size had the least. Also, nearly all components of seed yield were positively highly significantly correlated with one another; the number of seeds per pod and the number of pods per plant accounted for 76% of the variation in seed dry weight per plant.

It would seem therefore that under the prevailing humid tropical conditions, the most important component of seed yield in soya bean is the number of seeds per pod, as affected by the sink size.
Chemical composition of seeds of some species of the genusGossypium
Authors: Khattab A. H. , Khalifa H. , Tinay A. H. El
Published: March 2009

Chemical analyses were carried out on the three main commercial varieties in the Sudan and some wild species ofGossypium.A genome-specific pattern was not found for either the oil content, fatty acids, amino acids or seed index.G. sturtianumdiffered significantly from the other species in oil content with a substantial amount of unsaturated fatty acids and of the essential amino acids. A breeding programme has been started to incorporate such desirable characters into the commercial varieties.
Relationships between the lean content of joints and overall lean content in steer carcasses of different breeds and crosses
Authors: Kempster A. J. , Jones D. W.
Published: March 2009

Dissection data for 753 steer carcasses from 17 breed-type x feeding system groups were used to examine the prediction of lean content in the side (half carcass) from the lean content of standardized wholesale joints. Different prediction equations were examined and the joints compared both in terms of predictive precision and the stability of their prediction equations between groups.

The relative precision of the joints for predicting weight of lean in the side depended on whether or not the prediction equation included joint weight. With side weight and weight of lean in joint as independent variates, there was little difference between most joints in precision, and the smaller joints, shin and leg (hind shin) appeared to be best because they are convenient and easy to dissect. The addition of joint weight to the equation improved considerably the precision of all the joints except the shin and leg. The coast and top piece gave the most precise predictions with the trivariate equation (residual standard deviations about the common regression line computed ignoring groups, RSD overall, were 1·44 and 1·48 kg respectively) and the fore rib probably offered the best compromise between cost and precision (RSD overall = 1·82 kg).

The stability of prediction equations between groups was influenced in a similar way by the inclusion of joint weight as an independent variate. The joints which gave the most precise predictions tended to have the most stable equations. The average biases between the actual group means and the means predicted using the trivariate equation computed ignoring groups were ± 0·46, ± 0·49 and ± 0·76 kg for the top piece, coast and fore rib respectively.
The coat and heat retention in cattle: studies in the tropical maritime climate of Fiji
Authors: Yeates N. T. M.
Published: March 2009

Heat-tolerance tests and observations on coat shedding were made on Santa Gertrudis and Hereford heifers of similar age in the warm humid climate of Fiji.

Coat shedding (which is influenced by day length) was normal in the locally bred, smooth-coated Santa Gertrudis whose heat-tolerance was good. However, the Herefords, which had come from New Zealand and had very woolly coats failed to shed properly and suffered serious heat stress.

Clipping and the use of a close-fitting jute rug demonstrated the specially high heatretaining properties of a thick natural coat of cattle hair; also the special need to select animals of low coat score for the very humid tropics.
Obligate autogamy inVicia fabaL.
Authors: Poulsen M. H.
Published: March 2009

Data on the inheritance of a closed-flower type inVicia fabaand its effect on bee visits and out-crossing are presented.

Closed flower was recessive to normal flower and segregation in theF2generation showed monofactorial inheritance. The flowers remained more or less closed, they lacked the typical scent and generally the bees avoided them.

Six per cent out-crossing was observed. It is suggested that if spontaneous self pollinating occurs the closed-flower habit could prevent out-crossing, and could be a valuable contribution to breeding an obligate autogamousVicia faba.
The induction of coincident superovulation and oestrus in the anoestrous ewe
Authors: Hunter G. L. , Bishop G. P. , Brown D. L.
Published: March 2009

Eight Merino and eight Dormer ewes, none of which had been on heat for 2–3 months prior to treatment, were given six intra-muscular injections of 30 mg. progesterone at 3-day intervals. The ewes were divided into four groups, each consisting of two Merinos and two Dormers. On the second day after the last progesterone injection, 1000 i.u. P.M.S. were administered to each of the ewes in group I. The remaining ewes each received an injection of 500 i.u. P.M.S. on either the first and second days (group II), the second and third days (group III), or the first and third days after the end of the progesterone treatment (group IV).

Five of the Dormer ewes, but not one of the Merino ewes, were served after the treatment. Mean ovulation rates for the four groups were 2·50, 2·75, 2·00 and 2·50, respectively, and the mean numbers of large follicles (i.e. those which were observed at laparotomy, approximately a week after treatment, to have a diameter of not less than 4 mm.) were 3·00, 2·75, 1·00 and 2·00, respectively. Contrary to expectation, it was observed that only one of the ewes (a Merino) showed evidence of a silent ovulation shortly before treatment.

It is suggested that (i) the amount of oestrogen produced by the ovarian follicles of the Merinos may have been exceptionally low, thus accounting for the non-occurrence of oestrus in these ewes, (ii) ovulation rates might be increased by greater reductions in the time between the last progesterone injection and P.M.S. treatment, and (iii) if silent heat in the Merino is rare, it may be simpler to induce coincident heat and superovulation in ewes of this breed by two injections of P.M.S. at 16-day intervals.
Some observations on the relation between objective measurement and visual grading of beef carcasses in queensland
Authors: Lawrie R. A.
Published: March 2009

1. Of various objective measurements carried out on six carcasses from each of the three Australian grades 1, 2 and Canner, the minimum depth of fat above the eye muscle at the quartering point distinguished the grades to the most significant extent, as would have been anticipated from the importance of finish in visual grading.

2. The iodine numbers of fat from the tissues of the steers examined were lower than those which would have been expected in English steers at a similar level of fatness.
The effect of leys on soil fertility. II. The effect of undersowing with grasses and legumes on the yield of a barley nurse crop
Authors: Jarvis R. H. , Hanley F. , Ridgman W. J.
Published: March 2009

1. Data from a long-term experiment providing information on the effects on barley of undersowing the crop with various common species of grasses and legumes are discussed.

2. There is no evidence that the yield of grain, yield of straw, 1000 grain weight or the nitrogen content of the grain was affected in any way by undersowing with any of these species.
The effect of supplementary heating on the rearing of pigs
Authors: Campbell R. C. , Paterson H.
Published: March 2009

1. An experiment was carried out at ten farms in four winters to compare the value of three methods of pen warming.

2. Complete information on weightgain was available in seventeen replicates; the average increase in weaning weight from the use of heat was 2·41 lb.

3. Information on survival was available for thirteen replicates; the average benefit from the use of heat was 0·58 pigs weaned per litter.

4. The farmers' comments showed that they considered heating to be of value.
The influence of the zero hour and length of the time unit on the variation of dry-matter excretion in balance experiments with poultry
Authors: Tyler C.
Published: March 2009

1. The frequency of excretion of droppings by hens varied considerably over the day and much of this variation appeared to be related to the disturbance of the birds by attendants.

2. Data relating to dry-matter excretions by five birds for 17 days were used to study the influence of zero hour and length of the time unit on variations in this dry matter.

3. It was found that, in this experiment, 14.00 hr. appeared to be the best zero hour, but it was suggested that, considering the heavy excretion of material around 06.00 hr. when the birds are first disturbed in the morning, 07.00 hr. might be the ideal time. Data from an earlier experiment supported this.

4. There was a decrease in variation up to a unit of time equal to 3 days and times not multiples of days gave greater variations. There were, however, considerable differences between birds.
The effect of different plant sources on the utilization of carotene by chickens
Authors: Ascarelli I. , Bondi A.
Published: March 2009

The possibility was examined of supplying vitamin A to chickens from the first days of life as carotene in green plants. Growth experiments were carried out with chickens till the age of 8 weeks. Different kinds of forage (horse-beans, Berseem clover, green oats, sweet potato leaves, cow-peas, corn-leaves) were given in quantities calculated to supply 300 μg. carotene per 100 g. feed; control groups received fish-liver oil, given at the level of 500 i.u. per 100 g. feed. Weight gains and extent of vitamin A storage in liver served as an indication of the utilization of carotene from different sources. The utilization of carotene from all the plants examined was sufficient to support normal growth, only in the groups receiving clover was growth found to be somewhat slower. Remarkable differences were found in the extent of liver storage, and that was taken as an indication of differences in activity of the carotene from the different sources.

Attempts to determine the reasons for these differences in liver storage capacity of the carotene from the various plants did not reveal the presence of any plant components enhancing or depressing vitamin A storage.

Similarly, no correlation could be found between digestibility coefficients of carotene in the different plants and liver vitamin A storage. This correlation seemed likely in sweet potato leaves only, the rather low digestibility coefficient found in these leaves may account, at least partially, for the low activity of this plant.

The stereoisomeric composition of the β-carotene of the different plants and the xanthophyll/carotene ratio are very similar in all plants tested and cannot account for differences in carotene activity of the plants studied.

The results of this work show that it is possible to satisfy the requirements of chicks for vitamin A from the first days of life by supplying certain forage plants. In practice, because of the variability of the carotene content in such plants, care has to be taken when estimating the amounts to be given. Green plants should be given to chickens freely or at least in liberal amounts.
The effect of variation in dietary protein concentration and energy intake on mineral accretion in early-weaned lambs
Authors: Davidson J. , McDonald I.
Published: March 2009

Mineral analyses for calcium and phosphorus were carried out on lambs which had been fed diets contrasting in protein or energy or calcium concentration and had been slaughtered at defined live weights. Despite considerable variation in rates of growth arising from the widely different nutritional programmes, the mineral content of these lambs at a given weight remained remarkably stable on practical diets.
The effect of pod removal on the reproductive development ofPhaseolus vulgariscv. Provider
Authors: Olufajo O. O. , Scarisbrick D. H. , Daniels R. W.
Published: March 2009

Phaseolus vulgaris(cv. Provider) was assessed as a vegetable and seed crop in southeast England. Experiments were designed to simulate ‘pick your own’ harvest systems which are becoming increasingly popular. Edible pods were removed on either one or two occasions at varying developmental stages, remaining pods being left to produce seed. The yield of edible pods increased considerably as pod removal was delayed but subsequent seed yield was reduced. However, depodded plants showed compensatory increases in mean seed weight so that seed yield reduction was less than expected.

Results are discussed in relation to decline in seed moisture content and the dual use of this crop for vegetable pod and seed. It is concluded that dual use is not convenient for large-scale agricultural operations. ‘Pick your own’ programmes utilize the potential of this crop more efficiently than present mechanical harvesting systems.
Crossing Merino and a coarse wool breed of sheep; a study of the birthcoat of lambs
Authors: Guirgis R. A.
Published: March 2009

Birthooat fibre types were investigated in Barki, Merino and their crosses. The halo hair grade was high in the Barki breed, in the Merino a wide range of grades occurred but the majority was low. A trend of a decrease in halo-hair grade and an increase in non-hairy birthcoats occurred with the increase of Merino proportion in the crosses. An anterior reduction in halo-hair density was encountered in all groups under study.

Fibre type arrays were all coarse in Barki and ¼ Merino, the ¾ Merino had 50% fine arrays and 75% of the Merino arrays were fine. A trend towards a maternal influence on the birthcoat was observed in the ⅜ Merino and ⅝ Merino; more fine arrays were encountered in lambs born to dams with more Merino proportion.

Within saddle and ravine arrays, CT/Pre-CT ratio was highly significantly correlated with the pre-natal check as indicated by Merino proportion.

It was suggested, from the birthcoat studies, that ⅝ Merino might be the best combination in the Merino crosses as far as the fibre type arrays were concerned.

Less coarse arrays were encountered in the birthcoat due to selection against kemp in rams used for breeding.