bluuebunny/crossref_metadata_2025 huggingface dataset:
Compensatory growth in immature sheep: II. Some changes in the physical and chemical composition of sheep half-carcass following feed restriction and realimentation
Authors: Drew K. R. , Reid J. T.
Published: March 2009

Experimental conditions and design were described in part I. Separable lean and fat were highly correlated with the carcass and whole body components of protein and ether extract. The carcasses of refed sheep at 45 kg empty body weight (EBW) had about 1 kg less fat and more lean than carcasses from sheep of similar weight which had been continuously fed. Restricting feed intake to 70% ad libitum gave carcasses that had more protein than those from sheep fed ad libitum both during continuous growth and after realimentation.

Sheep that had lost 25% EBW to 26 kg and then were refed to 31 kg EBW had 34% less separable carcass fat than sheep which had been continuously fed to EBW of 36 kg and then had lost weight from that level to 31 kg EBW, and the separable fat was higher in water content than during normal growth (an effect shown consistently in realimented sheep).

Severe underfeeding rapidly reduced bone water but bone ether extract continued to accumulate. After a period of refeeding, bone fat was rapidly mobilized and bone water quickly returned to normal. During early weight loss following food intake reduction, there was a larger decrease in carcass water than expected, and most of the discrepancy could be accounted for by the disproportionately large loss of water from bone and separable fat.

It is concluded that during early regrowth there is a marked stimulus of lean tissue growth and depressed fat synthesis. After this initial period, growth rate of carcass tissues is not greatly different from that found in continuously growing sheep although there is some evidence of a small positive rate of protein growth effect following through to 45 kg EBW in the refed animals. The ratio of muscle gain to fat gain from 30 to 40 kg EBW was 2·23 in realimented sheep and 1·08 during normal growth.
Feed additives to diets supplemented with copper for growing pigs
Authors: Braude R. , Hosking Zena D.
Published: March 2009

Results of a co-ordinated trial carried out at 19 centres and involving 632 growing pigs indicated that the performance of pigs receiving diets supplemented with copper sulphate, at 250 mg Cu/kg diet, can be improved by the addition to the diet of 10 mg/kg of ‘Payzone’ or 50, reducing to 20 mg/kg, of ‘Grofas’. Zinc bacitracin, 50 mg/kg diet, was not effective. There were no marked effects on carcass quality.
Nutrient cycles involving phosphorus and potassium on livestock farms in Northern Ireland
Authors: Adams S. N. , McAllister J. S. V.
Published: March 2009

A method is described of determining the fertilizer P and K requirements of livestock farms from a knowledge of the stock carried and the crops grown on the farm as a whole. Recycling of P and K through organic manures is put on a rational basis and the fertilizer P and K needed to keep soil P and K at an adequate and constant level is easily measured.

A pilot scheme on 100 Northern Ireland farms is testing the method's value for giving advice. It is readily acceptable to advisers and farmers and is enabling substantial savings of fertilizers to be made.
The response of swede varieties and their hybrids to soil pH
Authors: Denton O. A. , Whittington W. J.
Published: March 2009

Four swede varieties and their sixF1hybrids were grown for 2 years in plots varying in pH from 4·2 to 8·4. Yields were highest at intermediate pH's and the average yield of the hybrids was greater than that of the parents. The plants on the low pH plots (4·2, 4·6, 4·7) were less infected with mildew than those at high pH (6·7, 7·7, 8·4). There was no marked resistance to mildew amongst the varieties. The response by the parents and hybrids was assessed by regression analysis and showed that the variety Reform was most reactive and Harvester most stable. Stability patterns appeared to be inherited. Inheritance patterns for yield and number of leaves were determined. It was concluded that selection for better swedes should be carried out in environments other than those to which the crop is currently restricted.
Results from experiments measuring the effects of large amounts of an NPK fertilizer on yield, tuber size and N, P and K contents of three potato varieties
Authors: Widdowson F. V. , Penny A.
Published: March 2009

Experiments with main-crop potatoes were made at Rothamsted and Woburn in 1971 and 1972 to measure the effects of applying four amounts (1260, 1880, 2510 or 3140 kg/ha) of granular NPK fertilizer (containing 13% N, 13% P2O5 and 20% K2O)for two pairs of varieties (Pentland Crown and King Edward at Rothamsted; Pentland Crown and Record at Woburn) planted either 30 or 45 cm apart in the row.

Yields of each variety were greatly increased by the first and second increments of fertilizer at each farm each year (mean increases of 5·5 and 5·2 t/ha respectively), but less by the third (2·1 t/ha); total yields were increased from 35·7 t/ha with 1260 kg/ha of fertilizer to 48·5 t/ha with 3140 kg/ha. As yields increased the proportion of small tubers (< 44 mm) decreased, whilst that of medium (44–70 mm) and large (> 70 mm) tubers increased.

The removals of N, P and K by each variety of potato were calculated; for those given 2510 kg/ha of 13·13–20 fertilizer, the mean amounts (kg/ha) removed were 154, 20·6 and 242 of N, P and K respectively, or 47, 14 and 58% of the amounts given. A balance sheet showed the amounts remaining in the soil after potato harvest.

Winter wheat was grown after the potatoes to value residual N. In 1972, when average amounts of winter rain fell, grain yields were increased by these residues on the heavy Rothamsted soil, but not on the sandy Woburn soil. In 1973, after an unusually dry winter, the residues consistently decreased yields because of lodging, showing that little N had leached during the winter. % N in the grain was increased by the fertilizer residues each year.
The effect of morphactin on the nutrient concentration of snapdragons
Authors: Asif M. I. , Ergenoglu F.
Published: March 2009

The effect of morphactin sprayed at 0, 0·5, 1·0, 1·5 or 2·0 mg/1 on the concentrations of several nutrients in snapdragons (Antirrhinum, majusL.) were studied under glasshouse conditions. Snapdragon plants treated with morphactin increased in K, and Mg but decreased in Ca, Mn, Cu, Fe, and Zn. Action of morphactin and nutrient element relationships are suggested.
Machine thinning of sugar beet: field trials with chemical and mechanical weed control
Authors: Hanbury L. F. , Maughan G. L.
Published: March 2009

Large-scale field trials in sugar beet were undertaken between 1961 and 1963 to examine the effects of chemical or mechanical weed control followed by machine thinning in terms of labour economy and yield of the crop. The seedling populations were left untrimmed by hand and, where the weed-control measures were completely effective or nearly so, the crops were left unweeded. Yield samples were taken both by hand and by machine so that the potential yield as well as the likely commercial yield might be determined. The chemical and mechanical methods that were studied saved about 75% of the normal labour demand and gave root yields 91.5% of those following hand work.
An estimate of the energy required for maintenance and live-weight gain by young grazing sheep
Authors: Grimes R. C.
Published: March 2009

1. The intake of grazing wethers was estimated from the in vitro organic matter digestibility of herbage samples collected from sheep with oesophageal fistulae, and total faecal collections.

2. Body water, estimated by isotope dilution, was used to estimate total body energy from estab-lished regressions relating body water to body composition.

3. Total body energy was then related to live weight by regression analysis, giving a value of 2044 kcal. per lb. over the range 68-90 lb. empty body weight. From this it was estimated that 2.41 lb. D.O.M. was required per lb. live-weight gain within this range.

4. Energy for maintenance was calculated by deducting D.O.M. required for gain from D.O.M. intake. These values were related to live weight by regression analysis to give a value of 1.31 lb. D.O.M./day for the maintenance of a 100 lb. sheep.
The seed productivity of perennial rye-grass varieties
Authors: Roberts H. M.
Published: March 2009

1. Seed plots of five perennial rye-grass varieties, S23, S24, S321, Melle Pasture and an experimental type, Ba6280, were established in 18 in. rows.

2. Each variety was subjected to hard grazing by sheep in September, at ear initiation in spring, and 3 weeks following ear initiation; one series of plots was left ungrazed. Three levels of spring nitrogen, 2, 4 and 6 cwt./acre ‘Nitro-chalk’ (21%N), were applied to subplots.

3. S321 produced significantly more seed heads and Ba6280 gave significantly fewer heads than S23, S24 and Melle. September grazing increased head production by 15%, whilst the two spring grazings gave fewer heads than the ungrazed plots. An increase in the rate of nitrogen application in spring favoured head production.
Studies in potato agronomy. I. The effects of variety, seed size and spacing on growth, development and yield
Authors: Bremner P. M. , Taha M. A.
Published: March 2009

1. Growth and development in relation to yield were studied in the two maincrop varieties King Edward and Majestic in 1959 and 1960. The effects of seed size and spacing were also investigated.

2. The total tuber yield, and more particularly the ware yield, of Majestic was greater in both years. This was associated with a longer period of tuber bulking in this variety, due, in 1959, to earlier tuber initiation, and in 1960, to earlier tuber initiation and greater persistence of tuber bulking. Large seed outyielded small seed, although the difference, particularly in ware yield, was relatively small. The seed size effect was associated with a difference in the length of the bulking period, in consequence of a difference in the time of tuber initiation. Total yield tended to increase with decrease in spacing distance; ware yield increased as spacing distance decreased from 24 to 18 in., but there was little difference between 12 and 18 in. spacing. In general, low seed rates performed better than might be expected.
The onset of the breeding season in Southdown ewes in subtropical Australia
Authors: Smith I. D.
Published: March 2009

Observations on the onset of the breeding season in a flock ofSouthdown ewes in subtropical Australia (latitude 27° S.) indicated that the mean date of onset during the years 1962-65 was 3 March, with annual means ranging from 11 February to 17 March. There was evidence that, under some circumstances, ovarian activity may be initiated before the summer solstice.

The onset of the breeding season was later in ewe lambs than in yearling and adult ewes and the mean age at puberty was 239 days.
Factors influencing flower and pod development in oil-seed rape (Brassica napus L.)
Authors: Tayo T. O. , Morgan D. G.
Published: March 2009

Experiments were carried out on oil-seed rape, variety Zollerngold, to determine the effects on flower and pod development when (1) the supply of carbon assimilates was reduced by shading or leaf removal at different stages of development or (2) the supply of assimilates to the more apically positioned flowers or pods on the terminal raceme was increased by removing 15 of the most basal flowers or pods.

A decrease in the production of carbon assimilates led to fewer flowers and pods developing to maturity and when the stress continued over most of the period of pod development the pods were smaller and had fewer seeds which were also lighter in weight.

Removal of the 15 basal flowers or pods led to more of the apically positioned flowers developing into mature pods and the other pods becoming heavier with bigger husks, heavier seeds and sometimes a greater number of seeds.

The results of a shading experiment in a controlled environment cabinet suggest that stresses in the supply of carbon assimilates around the time of anthesis are particularly harmful since in addition to reducing the number of pods which develop they appear to restrict the capacity for compensatory growth in the pods that remain when the supply returns to normal.
Thermal sweating in different body regions of sheep
Authors: Rai A. K. , Mehta B. S. , Singh M.
Published: March 2009

Although sheep combat thermal stress mainly by panting, a sizeable amount (40%) of total evaporative heat loss, is from sources other than panting (Hales & Brown, 1974). The frequency of sporadic discharge of sweat glands increases with increase in ambient temperature and is accompanied by a decline in respiration rate (Bligh, 1961). The wool coat can reduce evaporative cooling but sweating may have cooling value in sheep breeds with open fleeces (Rai, Singh & More, 1978). In sheep, the number and size of the sweat glands (Waites & Voglmayr, 1962) and the quantum of sweat production in a particular time period (Ghoshal et al. 1977) varies in different body regions. In view of the possible significance of surface evaporative cooling, thermal sweating in different body regions of sheep was investigated.
The growth and development of the beef qualities of Angoni cattle (East African shorthorn zebu). Part II. Linear growth and carcass characters
Authors: Walker C. A.
Published: March 2009

Part I described the growth of Angoni cattle as shown by changes in live weight. This Part deals with proportional growth as shown by linear growth and carcass characters.

LINEAR GROWTH

A virtually complete summary of the basic work on linear growth has been given by Brody (1945) and specific references will therefore be quoted only as required for discussion.
X-ray diagnosis of pregnancy in sheep with special reference to the determination of the number of foetuses
Authors: Ardran G. M. , Brown T. H.
Published: March 2009

1. Sixty-four Dorset Horn ewes and sixty Half- Bred ewes were X-rayed in the pelvic region at stages of pregnancy between 51 and 110 days.

2. Diagnosis of pregnancy and estimates of the number of foetuses carried were made from the X-ray film.

3. Over the range of gestation stages examined, interpretation of the number of foetuses present was found to be most accurate at stages between 91 and 110 days.

4. An accurate estimation of whether the ewe is pregnant or barren can be made from 50 days onwards.
Fertilizer experiments on maincrop potatoes 1955–61
Authors: Boyd D. A. , Dermott W.
Published: March 2009

Results are given of 124 factorial experiments testing N, P and K fertilizers for maincrop potatoes; the experiments were done by N.A.A.S. Soil Chemists in the years 1955–61. The experimental sites were in sixteen groups, corresponding to particular soil series or complexes.

There were substantial differences in mean yield and in response to the lower levels of P and K between soil series; the influence of soil was less at higher rates of application. Alternative methods of soil classification which appeared to be associated with response were texture, experiments on the lighter-textured soils showing higher responses to K; and depth of freely drained soil, soils with impeded drainage being associated with larger P responses. Responses to P and K were particularly large on soils in Wales and N.W. Cumberland.
Hereditary variation in resistance to Verticillium wilt within cultivated lucerne
Authors: Fyfe James L.
Published: March 2009

Natural infection by Verticillium albo-atrum occurred in two experiments, one comparing test crosses of inbred parents, the other a complete set of crosses between non-inbred parents. Although the uncontrolled variation was rather large, significant differences between progenies were detected in both cases. The differences were mainly accounted for by differences in general combining ability among the parents but not entirely so in the second experiment.
Results from experiments on winter barley measuring the effects of amount and timing of nitrogen and some other factors on the yield and nitrogen content of the grain
Authors: Penny A. , Widdowson F. V. , Jenkyn J. F.
Published: March 2009

Seven experiments on winter barley, made during 1979–81, measured the effects of several amounts of nitrogen, applied at different times in spring, on grain yield and nitrogen content. All of these experiments also tested a growth regulator applied in spring, and five of them tested fungicide sprays. In 1980 the experiment at Rothamsted also tested sowing dates, and an eighth experiment, also at Rothamsted in 1980, tested sowing dates and mildew fungicides applied in autumn or spring. In all the experiments treatments were tested in factorial combination.

N applied in February was less effective than N applied in March and both were less effective, in terms of grain yield, than N applied in April. Divided dressings were best applied in February and April or March and April; effects on % N in grain followed the same pattern and so, therefore, did the efficiency of uptake of fertilizer N. The growth regulator consistently reduced the length of the straw and diminished lodging; it increased yields in five of the seven experiments in which it was tested.

Responses to fungicides were inconsistent from year to year. Sowing in September rather than in October 1979 increased yield in both of the experiments at Rothamsted in 1980, especially of the 6-row variety Hoppel.
Food intake in sheep following intraruminal infusion of extracts from lucerne silage with particular reference to organic acids and products of protein degradation
Authors: Buchanan-Smith J. G. , Phillip L. E.
Published: March 2009

Sheep were infused intraruminally with iso-osmotic solutions of saline, organic acids or lucerne silage extracts with or without additional acids and products of protein degradation found in silage. The post-ingestive effects of silage constituents on food intake were assessed by measuring the voluntary consumption of high dry matter silage over a 20 h period following feeding. In Expt 1, three different silage extracts each depressed food intake up to 4 h following feeding. In Expt 2, one of these extracts, to which 40 g of γ-amino butyric acid (GABA) was added, depressed intake up to 4 h following feeding; with the further addition cf 10 g α-amino butyric acid (AABA) and 28 g amines to this extract, intake was enhanced within 0·5 h but depressed from 4 to 8 h following feeding. In Expt 3, infusion of organic acids alone did not significantly depress food intake relative to saline, nor was there a discernible effect on food intake when graded levels of nitrogenous constituents from silage were added to the infusates. In Expt 4, infusion of an extract, to which only AABA and four other amines were added, depressed cumulative intake up to 8 h following feeding and had a more pronounced effect on food consumption than infusion of the extract with these constituents together with GABA. It was concluded that soluble constituents in silage can inhibit intake but no single constituent is primarily responsible.
Applying chlormequat to Triticum durum: response of the crop in the absence of lodging
Authors: Green C. F. , Ivins J. D. , Hunter B. , McDonald H. G.
Published: March 2009

Classically the plant-growth regulator chlormequat (2-ohlorethyl trimethylammonium chloride, CCC) is applied to bread wheat crops (Triticum aestivutn L.) to shorten the basal internodes of the culm (Koranteng & Matthews, 1982) and thus prevent lodging (Cyanamid, 1966). Further, yield variations in cereal crops can be induced by chlormequat application in the absence of lodging. These effects may result from a manipulation of growth (e.g. barley: Koranteng & Matthews, 1982; wheat: Wunsche, 1971; triticale: Hankins, 1975) or development (e.g. barley: Wunsche, 1972; wheat: Harris, 1978; triticale: Green & McDonald, 1985).
Male sterility in field beans (Vicia faba L.). IV. Use of cytoplasmic male sterility in the production of F1 hybrids, and their performance in trials
Authors: Bond D. A. , Fyfe J. L. , Toynbee-Clarke Gillian
Published: March 2009

1. A method of producing hybrid beans with the aid of a cytoplasmic male-sterile is described.

2. Most of the requirements of large scale production of hybrid seed can be met: use of genetic markers showed that the male sterility allowed 100% cross fertilization; there was no evidence of a deficiency of insect pollinators near Cambridge; and fertility restoring lines are available.

3. The importance of being able to maintain a high level of sterility in the female parent line is emphasized. Methods of improving the proportion of sterile plants in the sterile phase of an inbred are discussed. The tolerable level of fertility in progenies of sterile parents depends on the level of sterility necessary in the female parent of the final cross. Five inbreds are being handled with less than 2% of fertile plants in their sterile phase.
Relationships between organic-matter digestibility, dry-matter intake and solute mean retention times in sheep given a ground and pelleted diet
Authors: Faichney G. J. , Gherardi S. G.
Published: March 2009

The relationships between organic-matter digestibility (OMD), dry-matter intake (DMI) and the mean retention time (MRT) of unabsorbed solutes in the gastrointestinal tract were examined using six fistulated, cross-bred, castrate male sheep. Measurements were made on each sheep at two different DMIs within the range 28–81 g D.m./(day. kg0·75). There were negative, curvilinear relationships between MRTs (both rumen and total) and DMI and positive, curvilinear relationships between OMD and MRTs. As a consequence, there was a negative, rectilinear relationship between OMD and DMI. OMD declined by 0·022 when DMI increased from calculated maintenance to twice maintenance. The proportion of the total MRT accounted for by rumen MRT did not change significantly; the mean value was 0·364 ( ± S.e. 0·010).
Exploiting the pasture capacitance probe in agricultural research: a comparison with other methods of measuring herbage mass
Authors: Crosbie S. F. , Smallfield B. M. , Hawker H. , Floate M. J. S. , Keoghan J. M. , Enright P. D. , Abernethy R. J.
Published: March 2009

The precision of the capacitance probe in detecting herbage mass differences between treatments has been assessed on a cross section of field trials in Otago-Southland, New Zealand. Used thoughtfully, the probe appears at least as good as any other alternative. Corrected meter readings from the probe may be used directly for relative ranking of treatments although calibration is desirable for interpretation purposes, and becomes essential when swards of widely differing composition are to be related. Considerable overall time savings, especially in the laboratory, are possible in comparison with other methods.
Influence of cotton-seed meal and barley grain supplements on intake, digestion, live-weight gain and wool growth in sheep fed NaOH-treated oat and wheat straw diets
Authors: Amaning-Kwarteng K. , Kellaway R. C.
Published: March 2009

Growth and digestibility trials were conducted to investigate responses of young cross-bred sheep to alkali-treated straws and supplements. Oat and wheat straws were coarsely milled, sprayed with NaOH solution and then sprayed with a solution containing N, S, P, Cu and Co, and mixed with powdered limestone. The treated straws were fedad libitumwith no supplement (0) or with 150 g/day of either cotton-seed meal (CSM) or whole barley grain (B). In a preliminary trial to study the effect of frequency of ort collection on intake of treated straw, consumption decreased (P< 0·05) when frequency of ort collection was reduced from once daily to once weekly. This was associated with an increase in the neutral detergent fibre content of the orts. During the growth trial, which lasted 105 days, intake of treated straw increased by 34%.

When no supplement was fed, digestibility of treated oat straw was higher (P < 0·05) and dry-matter intake lower (P< 0·05) than that of treated wheat straw. However, calculated intakes of metabolizable energy (ME) and measurements of growth and wool production were similar on the two straws (P> 0·05).

When supplements were fed, there was no effect on intake of the treated straws. Mean live-weight gains were 51·4, 80·2 and 77·3 g/day on treatments 0, CSM and B respectively (P< 0·01). This was associated with higher intakes of ME (P< 0·01) which accounted for 73% of the variation in live-weight gains. Mean clean wool growth was 7·6, 10·5 and 9·3 g/day on treatments 0, CSM and B respectively (P< 0·01). This effect was associated more with nitrogen (N) absorption than with ME intake (80 and 48% of the variation in wool growth respectively).

It was concluded that the treated straws provided sufficient nutrients for modest growth in young sheep, that the supplements had no effect on intake of the treated straws and that additional live-weight gain and wool growth obtained by feeding CSM and B were associated with energy intake and nitrogen absorbed respectively.
Studies on Awassi sheep in Lebanon:I. Production traits of a flock
Authors: Rottensten Knud , Ampy Franklin
Published: March 2009

1. The Awassi ewes reached an average live weight of 45 kg at two years of age and a mature weight of 57 kg at four years of age.

2. The average yearly production of grease wool has been 2·2 kg.

3. When rams were kept with the flock throughout the year approximately 60% of the lambings occurred during January–February. It declined rapidly during the following months and no lambs were born in July–August.

4. Single lambs had an average birth weight of 4·6 kg for males and 4·3 for females. Twin lambs were about 20% lighter than singles. The corresponding weaning weight at two months of age was 17·9 and 16·8 for singles and 13·4 and 12·4 for twins.

5. The twinning rate increased from 5% at first lambing to 30–35% at 6th lambing, when the ewes were about seven years old.
The relationship between rumination and the amount of roughage eaten by sheep
Authors: Gordon J. G.
Published: March 2009

1. The jaw movements of four sheep were recorded while they were consuming a daily diet consisting of a constant concentrate allowance along with a hay intake varying from 25 or 50 g. daily by daily differences of 25 or 50 g. up to maximum voluntary intake.

2. Rumination increased with hay intake in a characteristic way. The actual time devoted to chewing when plotted against hay intake produced a curve consisting of a rapid rise, a fairly level part, a further gradual rise and a final levelling-off. This was less clear when the total rumination time or the total number of regurgitations were compared to the hay eaten.
The oxygen requirement of crop roots and soils under near field conditions
Authors: Brown N. J. , Fountaine E. R. , Holden M. R.
Published: March 2009

1. Agricultural crops can be grown to maturity with their root systems and associated soil sealed into 1680 1. respirometers. The crops appeared to grow normally and produced the expected agricultural yields.

2. The mean daily oxygen consumption at maturity of the roots of the following crops grown at normal agricultural spacings were: potatoes 2·8 l./m2, marrowstem kale 5·6 l./m2 and tobacco 3·0 l./m2.
Studies in the lignification of grasses. I. Perennial rye-grass (S 24) and cocksfoot (S 37)
Authors: Johnston Margaret J. , Waite R.
Published: March 2009

1. Two perennial grasses, rye-grass S24 and cocksfoot S37 have been sampled at 7 to 10-day intervals from the stage of growth just prior to flower emergence to seed shedding. Each sample was separated into leaf, leaf sheath, stem and head (where present) and the fractions examined histologically for lignin formation and chemically for lignin and nitrogen percentages. Thein vitrodigestibility of most of these fractions was also determined.
A comparison of the deep-body temperature of Hereford and zebu cows recorded continuously by radio-telemetry under similar field conditions
Authors: Bligh J. , Lampkin G. H.
Published: March 2009

1. A radio-telemetric system linked to a thermistor- probe embedded in deep muscular tissue has been used to record continuously variations in deep-body temperature during 46–66 hr. in three Hereford (temperate) and three East African zebu (tropical) cows under similar temperate field conditions.

2. The limitations of the ‘probe’ technique for measuring deep-body temperature are discussed.
The use of ‘worm-free’ sheep in grazing experiments
Authors: Spedding C. R. W. , Large R. V. , Brown T. H. , Wilson I. A. N.
Published: March 2009

1. It has proved possible to operate a ‘worm-free’ area in which sheep grazing experiments can be carried out, without significant interference from disease.

2. The organization of such a unit is described and the results are presented in terms of the problems and difficulties which have been encountered during 4 years of continuous and increasing use. There is no apparent reason why these problems should increase with time.
Effect of urea and ammonium sulphate applied before sowing on sudangrass seedlings
Authors: Worker G. F.
Published: March 2009

Studies were conducted to determine possible leaching or fixation problems in growing sudangrass (Sorghum Sudanese Stapf.) when urea, ammonium sulphate plus triple superphosphate, and ammonium polyphosphate fertilizer were applied as a seed-bed application to the very sandy soils of the Libyan Sahara near the Kufra Oasis. The effectiveness of the nitrogen source was measured by plant colour, leaf analysis, and seedling height.

The urea nitrogen plus single superphosphate when applied and watered-in did not supply enough nitrogen to obtain a vigorous green seedling compared with ammonium polyphosphate (21% N, 53% P 2O6), which produced excellent vigorous green seedlings. The ammonia source supplied more nitrogen than the urea imder the conditions of these trials.

The application of urea 1, 2, 4, and 8 days before sowing was inadequate in supplying nitrogen to meet the early demand of the sudangrass seedlings. Sudangrass seedlings after 26 days were only 5–6·3 cm tall. With a seed-bed application of 36–72 kg N/ha as ammonium sulphate under comparable circumstances, sudangrass seedling height was 21·7 cm. The plants receiving no nitrogen applied before sowing were 6·7 cm high, similar to those which received urea.

Under these virgin sandy soil conditions, the ammonium sulphate and ammonium polyphosphate (21% N, 53% P2O5) fertilizers applied to the seed bed were retained within the root zone in sufficient amounts to give a vigorous, non-deficient sudangrass seedling. Nitrogen from urea was deficientand presumed leached beyond reach of the seedling root when applied to the seed bed. Applied post-emergence, however, urea was a very satisfactory source of nitrogen.
Prediction of the lean content of lamb carcasses of different breed types
Authors: Kempster A. J. , Avis P. R. D , Cuthbertson A. , Harrington G.
Published: March 2009

Carcass data for 424 castrated male lambs, comprising seven breed-type groups, were used toevaluate a series of linear measurements, subjective scores and the lean content of sample joints as predictors of percentage lean in carcass. The groups represented the main types of British lamb and mean carcass weights ranged from 12·8 kg (Welsh Mountain) to 20·8 kg (Lowland Longwool). Lambswere selected from commercial abattoirs to cover the ranges of fatness and conformation normally found in practice within each group. The pooled within-group S.D. for percentage lean was 3·70 and theoverall S.D. (ignoring groups) was 3·96.

Predictors were compared in terms of precision and the stability of their prediction equations. Of the characteristics measured on the intact carcass, subjective scoring of external fatness gave the most precise prediction both within groups and overall (R.S.D.within = 2·82, B.S.D.overall = 3·17). Fat thickness over the eye muscle (0) was the best predictor among those taken on the quartered carcass (R.S.D.within = 2·76, R.S.D.overall =3·00). The most precise individual predictors were percentage lean in the best end neck and shoulder joints (R.S.D.within = 1·51 and 1·59 respectively). Among pairs of predictors not involving dissection, the combination of C and percentage kidney knob and channel fat in the side gave the most precise prediction (R.S.D.within = 2.51, R.S.D.overall = 2·68). The stability of the prediction equations between groups tended to increase with the precision of the predictors. Among the more precise predictors, the equation for percentage lean in the leg was a notable exception, being particularly variable from one group to another.
A note on the difference between blood urea of buffalo and cow calves
Authors: Mehra Usha R. , Nath K. , Ranjhan S. K. , Chetal Urmila
Published: March 2009

Three buffalo calves and four Holstein x Hariana cross-bred calves of 4–6 months of age were fed for 21 weeks either on a normal protein ration according to National Research Council (1966) standard or 25% below or above it. The scheme of feeding was as follows:

Blood urea was determined every week from 6th to 21st week except in 10th, 14th and 15th week. When the animals attained the age of 15–17 months, their blood urea was again determined.

Blood urea of buffalo calves was found to be significantly higher than that of cow calves under similar conditions of feeding from 4 to 11 months of age. This difference disappeared at 15–17 months of age. Probable causes for this difference between species are discussed. Blood urea in both species tended to increase on high protein and decrease on low protein rations.
Effect of sodium on the growth of and ion uptake by barley, sugar beet and broad beans
Authors: Hamid A. , Talibudeen O.
Published: March 2009

The effect of soil salinity (ECerange 2–9 mmhos/cm) on the growth of and ion uptake by barley, sugar beet and broad beans (crops increasingly sensitive to salinity) was investigated in a glasshouse experiment.

Barley and sugar-beet yields benefited from the added Na in the soil but broad beans were always adversely affected. Changes in growth and ion uptake are discussed in terms of Na:K synergism and antagonism.

Sodium:potassium antagonism was observed in barley just after germination, and in sugar beet throughout growth, but not in barley at other growth stages nor in broad beans. Greater Na uptake promoted increases in dry-matter yields of all plant parts with barley and sugar beet, indicating that Na played a specific role in their metabolism. In sugar-beet roots, sugar concentrations and dry-matter yields increased with added Na by half as much more than without added Na, suggesting that Na is an essential nutrient.

We conclude from our experiments that the effects of salinity caused by Na salts when water is not limiting, is related not only to plant species but also to their stages of growth.
Fertility of young Cashmere goats after laparoscopic insemination
Authors: Ritar A. J. , Ball P. D.
Published: March 2009

Maiden 18-month-old Cashmere does (JV=254) were inseminated laparoscopically with frozenthawed semen after treatment with Controlled Internal Drug Release devices and pregnant mare's serum gonadotrophin (PMSG) in the breeding season of 1989 in Tasmania. Kidding rates(does kidded/inseminated) were not statistically different after the insemination of 1, 5 or 25 × 106 motile spermatozoa (50·0, 55·8 and 56·4%), andfor semen frozen by the pellet or straw methods (56·8 and 50·8%). The fertility results suggest that the critical threshold may not have been reached at 1 × 106 frozen-thawed motile spermatozoa.
Seasonal variation in semen characteristics of Friesian bulls in Iraq
Authors: Dessouky F. , Juma K. H.
Published: March 2009

A total of 1659 ejaculates was collected from four Friesian bulls imported from Europe and ten of their offspring born in Iraq while in regular artificial service at the Abu-Ghraib Experiment Station. The work covered a period from 1 January 1965 to 30 June 1967.

The five semen characteristics, volume, density, mass activity, individual motility and pH were studied and the influence of age of bull and season on these characters was investigated. The relationships between the characters were also investigated.

Deterioration was observed in volume of ejaculate, density, mass activity and individual motility in the Iraqi Friesians. Influence of season on all semen characters lacked significance with the exception of mass motility in the European Friesian bulls (P < 0·05). Highly significant positive correlations were found between most of the characters studied.
The mineral composition of hay and silage grown in Scotland in relation to the A.R.C. standards for the mineral requirements of dairy cattle
Authors: Hemingway R. G. , MacPherson A. , Duthie Alison K. , Brown Nora A.
Published: March 2009

Samples of hays (132) and silages (146) were analysed for calcium, phosphorus, magnesium, copper and manganese. Assessments were made of their ability to supply minerals to cattle in accordance with the A.R.C. (1965) minimal requirements.

The concentrations of all these minerals were greater in silage than in hay. The proportions of the hay samples which in 20 lb of dry matter, provided inadequate amounts of minerals to maintain cattle of 1100 lb live weight were 4% (Ca), 98% (P),21% (Mg), 90% (Cu) and 39% (Mn). In a similar manner 15 lb of silage dry matter proved inadequate to a comparable degree. For the samples examined 4% (Ca), 99% (P), 19% (Mg), 62% (Cu) and 15% (Mn) did not meet the proposed standards.

Data are presented to indicate the amounts by which a variety of cattle diets based on hay and silage fail to meet the A.R.C. (1965) minimal requirements in respect of calcium and phosphorus intakes for milk yields up to 4 gal.
Some aspects of body temperature regulation in sheep
Authors: Webster M. E. D. , Johnson K. G.
Published: March 2009

Skin temperatures, deep body temperatures and respiratory rates have been measured in Southdown and Merino sheep following feeding, and during infra-red irradiation, rumen infusions of hot and cold water, and cold exposure induced by shearing. The increases in respiratory rate and skin temperatures induced by infra-red heating and the heat increment of feeding were reversed by addition of iced water to the rumen and were suppressed by shearing. These responses could not be systematically related to particular body temperatures in the sheep and appeared to be continuously variable rather than ‘all-or-none’ phenomena. Considerable overlap was observed between respiratory and vasomotor mechanisms of thermoregulation. Measurements of the surface area and weight of ears and legs showed that these regions contribute approximately 23% of the surface area and 8% of the body weight in Merino sheep. Calculations suggested that up to 70% of the additional heat produced in the 2 h after feeding in sheep may be stored in the tissues through increase in mean body temperature. Sheep kept in short wool throughout the winter appeared to establish a new thermoregulatory ‘set-point’ associated with lower rectal temperatures than those in sheep with a full fleece.
The nutritive value ofPanicum maximum(guinea grass). III. Factors affecting voluntary intake by cattle and water buffaloes
Authors: Johnson W. L. , Hardison W. A. , Ordoveza A. L. , Castillo L. S.
Published: March 2009

Dry-matter intake (D.M.I.) fromPanicum maximum(guinea grass) was studied in digestibility trials with Holstein and water buffalo bulls and in a feeding trial with lactating cows.

Differences in voluntary D.M.I. per unit body weight0·73between the Holsteins and water buffaloes were not significant. Average D.M.I. for all bulls in all main trials was 2·16 kg per 100 kg B.W. Average D.M.I. by the lactating cows was 2·08 kg per 100 kg B.W., for all practical purposes the same as for the bulls.

D.M.I. was not related to stage of maturity or season of harvest of the guinea grass. Intakes of digestible protein, T.D.N., and digestible energy in different seasons and at different growth stages were related to the percentage of those nutrients in the grass.

Correlation coefficients were 0·68 between D.M.I. and B.W.0·73, 0·59 between D.M.I. and T.D.N. content, and 0·58 between D.M.I. and crude protein content, D.M.I. was not closely related to dry-matter content (r= 0·30) or crude fibre content (r= 0–01) of the guinea grass.
Breeding for increased nodule tissue in white clover (Trifolium repens L.)
Authors: Jones D. Gareth , Burrows A. C.
Published: March 2009

The results of progeny tests of families of F1 and F2 selections derived from S 100 white clover are reported. The selection criterion was a high total nodule mass per plant coupled with an effective symbiosis with a known effective strain of Rhizobium trifolii. Selection for increased nodule volume produced a correlated increase in nodule number. F1 and F2 had significantly higher means than S 100 but F2 was not significantly higher than F1.

Scores for nodule mass showed a significant increase in F1 and a smaller but insignificant increase in F2. An estimate of the efficiency of nitrogen fixation on a unit-nodule basis indicated that as nodule size increased efficiency decreased.
Co-ordination of stem elongation and Zadoks growth stages with leaf emergence in wheat and barley
Authors: Kirby E. J. M. , Appleyard M. , Simpson N. A.
Published: March 2009

Leaf emergence, apex development stage, internode length and Zadoks principal growth stage 3 were measured over 3 years at several sites.

Internode elongation and Zadoks score were strongly related to the number of emerged culm leaves. The final length of the most basal internode was very variable and contributed to variation in the relationship between Zadoks stage 30 and the number of emerged culm leaves. Variation in the length of the basal internode was related to the final number of culm leaves. Most plants had six culm leaves but the number of leaves was affected by sowing date. In an experiment where sowings were made from September to March, stem elongation and Zadoks stage 30 started at a later stage of apex development in later sowings.

Recognition and prediction of culm elongation and number of emerged culm leaves is important for the application of growth regulator and fungicides. Combined with functions to predict the rate of leaf emergence and final number of leaves, the relationships described in this paper may enable Zadoks principal growth stage 3 and number of emerged culm leaves to be predicted.
Effect of lα-hydroxycholecalciferol on calcium and phosphorus metabolism in sheep given high or low calcium diets
Authors: Braithwaite G. D.
Published: March 2009

The relationship between calcium and phosphorus metabolism in wether sheep given high or low Ca diets, with or without 1α-hydroxycholecalciferol (1α-0H-D3) has been studied by a mineral balance and radioactive technique.

Ca absorption was not related to Ca intake but was stimulated by 1α-OH-D3. More Ca was absorbed by treated animals from the high Ca diet than from the low diet and all the extra Ca absorbed was retained, increased retention being brought about largely by an increase in the rate of bone accretion.

P absorption was increased to approximately the same extent from both diets suggesting that stimulation was due to the 1 α-0H-D3treatment rather than increased Ca absorption. Whereas the extra P absorbed from the high Ca diet was retained, together with Ca, in bone and soft tissues, that absorbed from the low Ca diet was largely excreted in the urine. It is suggested that this difference in P retention reflects a difference in availability of Ca for retention in bone and P retention was in fact found to be directly related to Ca retention.

The roles of secretion of P into the gut, absorption of P from the gut and urinary excretion of P are discussed in relation to P homoeostasis.

As absorption of P from the intestine and loss of P to bone, soft tissues and urine increased, so endogenous faecal loss decreased until it reached a value of approximately 35 mg/day per kg body weight when it remained constant. It is suggested that this value may represent the inevitable loss of endogenous P in the faeces from a hay and concentrates diet and that this minimum value may have a bearing on the calculation of P requirements.
A note on the in vitro dry-matter digestibility determination of mixed herbage and browse samples collected with oesophageal fistulated steers
Authors: Shorrock C.
Published: March 2009

The determination of in vitro dry-matter digestibility (DMD) of grass and pasture legumes under both temperate and tropical conditions is well established (Tilley & Terry, 1963; Minson & McLeod, 1972). One application of the in vitro DMD estimation of pasture samples is, together with an estimate of faecal output, the measurement of the herbage dry-matter intake of grazing cattle. Pasture samples are usually collected with oesophageal fistulated cattle. This technique is well documented and has been reviewed by a number of authors (Langlands, 1975; Minson et al. 1976).
Effect of amendments and saline irrigation water on soil properties and yields of rice and wheat in a highly sodic soil
Authors: Dubey S. K. , Mondal R. C.
Published: March 2009

A field experiment at Gudha Experimental Farm, Central Soil Salinity Research Institute, Karnal, India, in 1983/84 evaluated the effect of gypsum (12·5 t/ha, 50% of gypsum requirement of soil), pyrite (10·2 t/ha, equivalent to gypsum on a sulphur basis), farmyard manure (FYM) (30 t/ha), gypsum + FYM, pyrite + FYM and a control, with saline (ECiW 4·0 dS/m) and non-saline (0·4 dS/m) irrigation water on soil properties and yields of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) in a highly sodic soil (pH 10·5, 96% exchangeable sodium). Application of these amendments enhanced the yield of both crops significantly, irrespective of the quality of the irrigation water used. Soil properties and crop yields were improved in the following order: control < FYM < pyrite < gypsum < pyrite + FYM < gypsum + FYM. Irrigation with saline water resulted in significantly higher yields of both crops than irrigation with non-saline water. Decreases in soil pH and exchangeable sodium and increases in exchangeable Ca + Mg and infiltration rate were greater after rice than wheat in the rotation, particularly when non-saline water was used.
Observations on the reproductive activity of tropical sheep in relation to the photoperiod
Authors: Symington R. B. , Oliver J.
Published: March 2009

A study has been made of the effect of a progressive increase in the hours of light each day on the sexual activity of German Merino, Persian Blackhead and indigenous ‘Native’ ewes.

Incidence of oestrous tended to be greater in ewes subjected to extended daylight than in ewes subjected to the natural photoperiod. This was particularly true during the latter stages of the study. Duration of oestrus was unaffected by the extended daylight but varied temporarily in both groups of ewes. The effect of extended daylight on duration of the oestrous cycle and on the incidence of oestrous cycles of normal or abnormal duration was not marked and differed between breeds. Extension of daylight to 19 hr. each day apparently did not prevent reproduction since several light-treated ewes inadvertently conceived, gave birth to and reared a healthy lamb after a gestation period of normal length.
Yields of maize, sorghum varieties and sorghum hybrids in the East African Lowlands
Authors: Doggett H. , Jowett D.
Published: March 2009

1. Sorghum is capable of giving substantial yields under dry conditions where maize fails.

2. Sorghum can consistently out-yield maize in some areas under conditions of apparently adequate or excessive rainfall.

3. Low soil nutrient status, and/or poor soil water relations, interacting with the amount of rainfall were probably responsible for the low maize yields where precipitation in the growing season exceeded 15 in.

4. Some hybrids originating in the U.S.A. may be of immediate value in dry areas of East Africa. Such hybrids are generally susceptible to bird damage and are more susceptible to Atherigona indica infuscate than local material. Hazera 726 shows less susceptibility to both these pests and is recommended for dry areas.