bluuebunny/crossref_metadata_2025 huggingface dataset:
A study of the principal factors affecting the establishment and development of the field bean (Vicia faba)
Authors: Soper M. H. R.
Published: March 2009

1. A survey of bean crops was carried out in the Oxford area in the years 1947–9 with the object of studying farmers' methods, and the factors affecting establishment and development of the crop in the field.

2. The season and the fertility status of the soil have a profound influence on the development of the crop, while plant density affects the growth of the individual plant.

3. Hard winters cause crop losses which may amount to more than 50% of the plants. Mortality continues throughout the season.

4. A warm dry spring and an equable summer temperature favour pod production more than hot, dry seasons.

5. High plant densities cause: (1) a reduced rate of pod formation on each plant over a wide range of conditions, but a greater reduction on poor land than under good conditions; (2) a reduction in stem formation on low fertility fields (but not on high fertility land); (3) a significant increase in pod production per acre on high quality fields.

6. A high level of fertility leads to significantly more pods/acre, owing to better plant survival and increased branching and podding.

7. Under conditions favouring vegetative growth, there appears to be some competition between stem production and pod production, for the correlation between stems/plant and pods/plant found on low fertility land and in dry seasons no longer holds under good growing conditions.

8. In an average crop, there is a very serious loss of flowers and partly matured pods, which may amount to 85% of the flowers formed.

9. This wastage may be due to (1) unsatisfactory pollination or self-infertility, (2) inadequate availability of certain plant nutrients, (3) unsuitable environmental conditions, particularly low light intensity in dense crops.

10. Botrytis cinerea can cause a high wastage of crop, but it did not figure prominently during the 3 years of the survey, and appeared to be associated with deficiency of potash and/or phosphate in the only two severe outbreaks that occurred.
Nutrition of the bacon pig XVI. The relative supplemental value of the proteins in extracted soya-bean meal and in white-fish meal
Authors: Evans R. E.
Published: March 2009

In continuation of our work on the relative supplemental value of animal and vegetable protein concentrates (Woodman & Evans, 1951), a study has been made of the proteins in extracted soya-bean meal. It is probable that vegetable protein concentrates may vary among themselves in nutritive value and that the proteins of ground-nut meal, which were the subject of investigation in our previous experiments, could not for this reason be regarded as representative of vegetable proteins in general. The same basal diet, composed of roughly 2 parts of barley meal and 1 part of fine bran, together with a little lucerne meal and minerals, was again used in the present investigation.
Cytological studies of sterile bulls with spermhead abnormality
Authors: Slizynska Helena , Slizynski B. M.
Published: March 2009

Cytological stvidies did not show any detectable structural changes which could be related to the spermhead deformity in a series of sterile bulls described by Hancock. The deformity according to Hancock consists of a deeply stained (in iron haematoxylin) area placed askew at the apex of the spermhead.

In spermateleosis it is connected with persistence of the shallow apical groove of the nuclear membrane observed only in earlier stages of development in normal cases. There is also a formation of vacuoles in the developing spermheads in the region of the apex and of the equatorial belt. The apex of the abnormal spermhead treated with Feulgen reagent appears to be cut off askew.

Formation of vacuoles in the developing spermheads may be related to some unknown changes in the nucleic acid metabolism of the spermhead. The absence of any chromosomal aberration, whether of quantitative or structural nature, may lead to the conclusion that the changes observed are due to a gene mutation.
The determination of the volatile fatty acids formed during the fermentation of grass/water mixtures
Authors: Barnett A. J. G. , Duncan R. E. B.
Published: March 2009

1. The use of the technique of gas-partition chromatography in the investigation of the formation of volatile acids in minced grass/water slurries is discussed.

2. Slurries kept anaerobically at 17, 37 and 62° for 13 weeks have been examined, and the amounts of the different volatile acids formed have been estimated. It has been noted that butyric acid forms most readily in the slurry at 37°, while in aerated slurries at 17°, the formation of volatile fatty acids is more speedy than under anaerobic conditions.

3. Only acetic, propionic and butyric acids have been noted so far, and the highest concentrations of the acids observed in any slurry were 5, 1·25 and 4% respectively.
A numerical description of breed structure
Authors: Robertson Alan
Published: March 2009

A method is suggested for the quantitative description of the genetic structure of pedigree breeds of animals. Results are given for eight breeds, showing that the number of herds controlling effective breeding policy is in all cases small.
The calibration of a photo-electric absorptiometer for the rapid estimation of counts of spermatozoa in bull semen
Authors: Cox C. P. , Melrose D. R.
Published: March 2009

1. An EEL mains-operated colorimeter has been calibrated to obtain rapid estimates of the concentration of spermatozoa in bull semen.

2. A general linear calibration relationship has been calculated givingh, the estimated concentration of spermatozoa per ml. of the original semen, as

wheredis the dilution factor andPdis the absorptiometer reading.

3. Under the circumstances of the experiments described, the accuracy of estimates from the above relation was about 1%, and it is considered that the instrument may be effectively used in semen determinations for artificial insemination and in most cases where a rapid determination is required.

4. Attention is drawn to the desirability of using standards and occasional check calibrations, and to the possibility that in routine use results may be slightly less accurate than those given above, which were obtained with laboratory determinations.
Physiology of seed yield in field beans (Vicia faba L.): I. Yield and yield components
Authors: Ishag Hassan M.
Published: March 2009

The growth and yield of four varieties of field beans were studied in field experiments in 1967 and 1968.

Seed yield of the varieties Albyn Tick, Herz Freya, Blue Rock and Maris Bead were similar (averaging 6600 kg/ha) in 1967, but in 1968 Albyn Tick and Herz Freya (averaging 6400 kg/ha) outyielded Maris Bead (5700 kg/ha). Yield in both seasons were substantially more than the national average yields for Britain (about 3000 kg/ha). In 1968, yields were 40% greater at 57 plants/m2 (7100 kg/ha) than at 36 plants/m2 (5100 kg/ha).

Yield was closely correlated with number of pods/plant. The number of pods/node regulated this rather more than the numbers of nodes forming pods. Mean seed weight and seed number/pod varied little between plant densities but variety means were significantly different.

Maximum numbers of immature pods were present in late June. By mid-July 35% of the immature pods had shed, mainly from the middle and top of the range of podbearing nodes.
Effects of kinetin on the growth and development of barley and its interaction with root size
Authors: Ruckenbauer P. , Kirby E. J. M.
Published: March 2009

In some plants the roots have been shown to be major sites of cytokinin production. The part they play in controlling growth and development of cereals was studied by spraying barley with kinetin solution and by changing the size of the root system. Two varieties of barley were grown in culture solution and kinetin was applied and root sexcised at the second-, third- or fifth-leaf stage. The kinetin in aqueous solution was sprayed on the leaves, and either most of the root-tips, or an equivalent weight of entire root strands, were removed. Kinetin increased both shoot apex development and the final ear size. The weights of the main shoot and the whole plant also wore increased, particularly by the later treatments. Removing entire root strands decreased the whole plant dry weight more than removing most of the root apices, but the main shoot weight was less affected. Kinetin interacted with root removal, though neither the interaction nor the main effect of root removal showed unequivocally that cereal roots are the site of cytokinin synthesis, possibly because new root tips were regenerated.
A technique for liver biopsy in sheep
Authors: Phillippo M.
Published: March 2009

In experiments at this Institute in which samples of liver were required for the estimation of mineral content, difficulty had been encountered in obtaining samples reliably, especially in pregnant animals using the technique described by Dick (1944) and Abdellatif (1968). It was decided to investigate the possibility of obtaining liver samples from sheep under direct vision using a laparoscope.
Observations on the effect of protein intake and stage of gestation on the proportion of urinary nitrogen excreted as urea in sheep
Authors: Robinson J. J. , Scott D. , Fraser C.
Published: March 2009

The effect of altering the level of protein intake on urea excretion in ewes was assessed in two separate experiments.

In Expt 1, 14 pregnant (during the last 20 days of gestation) and 10 non-pregnant ewes were each offered a different level of digested N intake in the range 5–25 g/day. At all levels of protein intake urea N excretion was lower in pregnant than in nonpregnant ewes.

In Expt 2, 21 pregnant ewe lambs were each offered one of three diets supplying mean intakes of 83 (T1), 113 (T2) or 147 (T3) g crude protein/day. During the last 100 days of gestation the mean levels of urea N excretion were 6·9, 11·0 and 15·2 g/day for T1, T 2 and T 3, respectively. The corresponding values for urinary N excretion were 9·3, 13·8 and 18·2 g/day. At all levels of protein intake urea N excretion was lower just prior to parturition than 95 days prepartum; the difference was correlated with lamb birth weight and maternal body-weight change.

A notable feature of both experiments was the low level of urea N excretion by the pregnant ewes in late gestation, at low protein intakes. It would appear that when energy intake is adequate the decrease in urea N excretion associated with pregnancy is a direct result of an increased N requirement for maternal and/or foetal growth.
Studies on goats: I. Effect of plane of nutrition on the reproductive performance of does
Authors: Sachdeva K. K. , Sengar O. P. S. , Singh S. N. , Lindahl I. L.
Published: March 2009

The project involved two breeds of Indian goats – Barbari and Jamunapari, three levels of energy and three levels of protein, making a total of 18 treatments. There being no specific recommendations for goats, the high, medium and low levels of energy (T.D.N.) and protein (D.C.P.) represented 125, 100 and 75% of Morrison's standard for sheep, respectively. A total of 97 Barbari and 87 Jamunapari does were allocated to the nine ration treatments and were bred within the breed naturally. The rations comprised a concentrate mixture (linseed cake and/or barley grain), dry roughage (gram bhusa), greens, mineral and trace-element mixtures and common salt. The effect of nutrition on reproductive performance, as revealed by the five and four kiddings completed in the Barbari and Jamunapari was as follows:

While the first kiddings did not indicate a sizeable effect, the subsequent ones showed a significant effect of nutrition. Almost all the does in the low-energy groups, irrespective of the protein levels, did not kid for the last kidding under reference.

The maximum percentage of twins was noted in high-energy-cum-high-protein (47·5%)and high-energy-cum-medium-protein (45·3%) groups of Barbari and Jamunapari respectively. The average twin-birth percentages, irrespective of nutrition, were 14·8, 37·3, 38·0 and 40·2 in Barbari and 9·0, 20·5 and 23·0 in Jamunapari respectively. Triplets, although rare, occurred within the Barbari but only one case occurred within the Jamunapari.

On average Barbari and Jamunapari had 2·0 and 1·5 kids per doe per year in the high-energy-cum-medium-protein group compared with 1·0 and 0·4 in the low-energy ones, respectively. Furthermore, high- and medium-energy groups had shorter intervals between kiddings compared with the low-energy ones.
Effects of initial phosphate intensity and sorption or buffering capacity of soil on fertilizer requirements of different crops grown in pots or in the field
Authors: Salmon R. C.
Published: March 2009

Rates of added P required for maximum yields of ryegrass grown in pots and of field tobacco and maize were related to functions of P intensity (I) and capacity (AQ/AI, or C) in soils. It was found that log I alone was negatively correlated with optimum fertilizer for ryegrass and tobacco, but not for maize. Capacity alone had little relationship with P requirements of tobacco but was significantly correlated, although having opposite effects, with those of ryegrass (positive) and maize (negative). Optimum fertilizer rates for all crops were best accounted for by multiple regressions including intensity and a capacity term together, using log C when P requirements were increased (ryegrass in pots, R2 = 0.94) or √C when they were decreased by increasing capacity (field tobacco, R2= 0.96; and maize, R2 = 0.98). Inclusion of both capacity terms with log I in regression was of no advantage with ryegrass and tobacco, but with maize all three terms contributed significantly to the correlation, log C tending to increase and √C to decrease fertilizer needs.
Formic acid as a silage additive
Authors: Wilson R. F. , Wilkins R. J.
Published: March 2009

Pure swards of cocksfoot and perennial ryegrass cut on three occasions and of lucerne cut on two occasions were ensiled in test-tube silos after three treatments: (i) unwilted without additive, (ii) unwilted after the addition of formic acid at 0-23 % of fresh weight, and (iii) wilted to a water content of about 70 %, with no additive. Replicate silos were opened at intervals up to 105 days in order to follow the course of fermentation.

Silages from the final sampling could be divided into two clearly defined groups. Those where the lactic acid content, expressed as a percentage of total fermentation acids (L %T), was over 60 (19 silages) were considered stable while those with a value less than 20 (5 silages) were considered unstable.

The addition of formic acid resulted in a reduction in pH of the ensiled material from 5–86 + 0–12 to 4–60 ±0–11. This value changed little during the first 6 days after ensiling but then fell as lactic and acetic acids were formed. Stable silages made from unwilted crops without additive contained more lactic acid than those made with formic acid, but the converse was true for unstable silages. The ammonia content of silages made from unwilted material was always lower when formic acid had been applied. Wilting before ensiling gave stable silages from all crops.
On measuring nitrification and recovery of aqueous ammonia applied to grassland
Authors: Ashworth J.
Published: March 2009

Contour diagrams, computed from analyses of soil around bands of aqueous ammonia injected under grass, show the distribution of both NH4-N and nitrifying bacteria.

When applied at 155 kg NH3-N/ha, either as 4·7 or 9·3 g N/m of injection slit, using knives spaced either 30 or 60 cm apart, aqueous NH3 was recovered and nitrified more slowly in the bands 60 cm apart. Cumulative yields of grass after 32 weeks were the same (715 ±30 g/m2) from plots injected at either spacing but growth was more even throughout the season from slits 60 cm apart.
Dormancy of paddy seeds in relation to different moisture contents of grains and dates of harvests
Authors: Sikder H. P.
Published: March 2009

Two dormant varieties of rice were harvested three times at intervals of 7 days after grain development and the seeds were subjected to different sunning and controlled humidity storage treatments. Germination percentages and moisture contents of the grains were recorded at intervals of seven days after harvest.

It was noted that the dormancy of the dormant rice seeds was broken early when the seeds were subjected to continuous sunning from sunrise to sunset, followed by the treatment where the seeds were preserved under 0 % humidity conditions at room temperature. There was no break of dormancy of rice seeds when the seeds were preserved under 94 % humidity conditions.

It was further noted that when the age of the seeds at the time of a germination test remained the same, the earlier the harvest, the earlier was the break of dormancy; and when the lapse of time after harvest remained the same at the time of a germination test, the later the harvest, the better was the germination.

It is suggested that dryness of the seeds helps in the early break of dormancy and wetness retards or completely stops the dormancy-breaking reactions. On drying, the kernels of rice seeds shrink in volume more than the glume covers resulting in an air-space between the glumes and the kernels. This air-space helps air-diffusion in and out of the seeds, resulting in quicker oxidation-reaction processes or possibly embryo respiration, and consequently the dormancy is broken early. Increase in temperature accelerates such reactions. It is further suggested that the dormancy of rice seeds depends on the interactions between the ‘embryo-sensitivity to inhibitors’ and the ‘state of oxidation-reaction processes’ inside the seeds.
Apparatus for the separate collection of faeces and urine from cows
Authors: Balch C. C. , Bartlett S. , Johnson V. W.
Published: March 2009

The cost of conducting digestibility trials with cows is high, due to the need for either elaborate equipment for separating faeces and urine or a considerable number of assistants to remain constantly behind the cows catching the excreta as they are voided. Manual collection of excreta was used extensively by earlier workers, and, in a recent report of the most suitable arrangements for experiments using this method, Eheart, Holdaway & Pratt (1945) found that one attendant was necessary for every cow on test with a trained chemist also present in the shed at all times.
The use of chromium sesquioxide to measure the digestibility of carotene by goats and cows
Authors: Chanda R. , Clapham Helen M. , McNaught Mary L. , Owen E. C.
Published: March 2009

The digestibility of carotene in dried grass was measured by the Cr2O3method in both cows and goats. In the goats the direct method was simultaneously used for comparison with the Cr2O3method.

The main conclusions were:

1. When mixed with the concentrate portion of the ration of lactating goats, Cr2O3was recovered in the faeces in four experiments in amounts equal to 100·0, 99·1, 99·1 and 96·0% of the amount ingested.

2. The apparent digestibility of carotene in the goat was measured both directly by the use of metabolism crates and indirectly by using Cr2O3as an indicator of equivalence of faeces and food. By the former method digestibilities of carotene in four goats were 68·7, 62·7, 61·8 and 59·6%. The corresponding digestibilities obtained from the same faeces samples by the Cr2O3 method were 67·4, 62·9, 61·8 and 58·9%.

3. In six cows, on the diet similar to that of the goats, the Cr2O3method showed that 59·3, 54·0, 54·4, 54·4, 57·1 and 55·5% of carotene was apparently digested.

4. Reasons for preferring the use of added Cr2O3to natural constituents of the food as a marker are discussed.

5. The individual results from cows and goats have been statistically analysed to partition the various sources of variance, and it has been shown that fewer animals for a longer time give a more reliable result than more animals for a shorter time.
Effect of some pesticides and herbicides on the rumen micro-organisms of sheep
Authors: Akkada A. R. Abou , Hassan M. A. , Naga M. A.
Published: March 2009

Lower concentrations of the herbicide M15stimulated thein vitrocellulose digestion and V.F.A. production by rumen micro-organisms. The herbicide Cotoran enhanced cellulose digestion but had no effect on V.F.A. production. The herbicide Dalapon decreased cellulose digestion and had little effect on V.F.A. concentrations. The herbicide 2,4·D had little or no effect on thein vitrocellulose digestion and V.F.A. production. Thein vitromicrobial activity was inhibited by the pesticide DDT. The effects of M152,4·D and DDT on V.F.A. production decreased with time. When the rumen fluid was fractionated, the V.F.A. production by the bacterial fraction was not significantly altered by the addition of 2,4·D and M15, whereas the activity of protozoal fraction was greatly enhanced. The response of V.F.A. production by washed suspensions of rumen ciliate protozoa to the addition of pesticides and herbicides was remarkably similar to that of rumen contents. Feeding M15(60 ppm) increased the ruminal V.F.A. over those in the control sheep whereas 2,4·D had no or little effect.
The effect of sowing date and season on growth and yield of oilseed rape (Brassica napus)
Authors: Scott R. K. , Ogunremi E. A. , Ivins J. D. , Mendham N. J.
Published: March 2009

Experiments made between 1967 and 1970 tested the effects of sowing oilseed rape on different dates in autumn and spring. Much greater oil yields were obtained from autumn sowings, due to higher seed yields and oil content, but the effect varied considerably between experiments, varieties and seasons. Autumn-sown crops flowered in late April or early May, and by the time pods were developing rapidly in June the leaves had senesced almost completely. Spring-sown varieties followed a similar pattern but about a month later, and did not reach the same peak in pod growth.

There was a major effect of sowing date, late-autumn sowings (after mid-September) giving lower yields than early-spring sowings. The best autumn sowings (early September) gave about 3 t/ha of seed, but late sowings less than half this; oil content also decreased with delay in sowing – from 45% to as low as 38%. Delayed sowing restricted growth, leaf area and pod production, and also had a slight effect on seed weight. Frost damage on flower buds appeared to be the cause of reduced yield from early sowing (August) in one experiment. In spring, the earliest sowing (late March) gave the best yields. Vigorous but late vegetative growth from the latest sowing (end of April) did not lead to high yields, possibly due to pest and disease effects.
Studies on particle size distribution in pig dietary constituents
Authors: Haigh P. M. , Eden A.
Published: March 2009

Studies were made of particle size distribution in meals produced from typical ingredients used in pig diets and of dietaries formulated from such ingredients. Each meal was subjected to a sieving procedure through standard sieves and the fractions retained by the sieves were weighed. The modes of expressing the results included moduli of fineness and uniformity and cumulative totals of oversize material, the latter forming the basis of the system preferred. Preliminary investigations into factors of loading weight, time of shaking and reproducibility of results led to the ultimate adoption of a standard technique of mechanical shaking of 100 g loads for 10 min. The technique was used to study particle size distribution in various cereals, cereal by-products, animal and vegetable protein sources and mineral mixtures employed in pig dietary formulations. The studies also included the particle distribution pattern in barley milled at varying grist sizes and in replicated samples of a commercial pig meal.

The suggested technique of characterizing particle size distribution should materially assist investigations into problems of pig health and productivity that appear to be associated with grist size of dietary meals.
Quantitative digestion of fresh herbage by sheep: I. The sites of digestion of organic matter, energy, readily fermentable carbohydrate, structural carbohydrate, and lipid
Authors: Ulyatt M. J. , Macrae J. C.
Published: March 2009

Sheep prepared either with a rumen cannula, or with a rumen cannula plus re-entrant cannulae in the duodenum and ileum were fed fresh ‘Ruanui’ perennial ryegrass (R), ‘Manawa’ short-rotation ryegrass (M) and white clover (C) at dry-matter intakes ranging from 450 to 1000 g/24 h.

The re-entrant cannulated sheep were given paper impregnated with chromic oxide (Cr2O3) once daily via the rumen fistula as a marker; recoveries of Cr2O3at the duodenum, ileum and faeces were approximately 75, 69 and 100% respectively. Regressions of Cr2O3-corrected digesta constituent flows (g/24 h) on intake were constructed and from these were calculated the sites of digestion of OM, gross energy, readily fermentable carbohydrate, structural carbohydrate and lipid between the stomach, small intestine and large intestine.

There were differences between pasture species in partition of OM and energy digestion. With M, digestion in the stomach was significantly less (P< 0·01) and digestion in the small intestine was significantly more (P< 0·05) than with either R or C. These partitions of OM and energy digestion changed with level of feed intake. A substantial proportion (9–18%) of the digestible OM and energy was apparently digested in the large intestine with all three herbages.

With all three herbages approximately 93% of the digestible readily fermentable carbohydrate and 90% of the digestible structural carbohydrate was digested in the stomach region.

Reasons for differences in gross efficiency of utilization between the pasture species in the order C > M > R were examined.
Effect of nitrogen fertilizer applied to the seed crop on the subsequent growth of early potatoes
Authors: Gray D.
Published: March 2009

Three experiments involving three early maincrop cultivars explored the effect of nitrogen fertilizer (0–301 kg N/ha) applied to seed potato crops on seed performance and the growth of the subsequent early ware crop.

The tuber N-content ranged from 1·1 g N/100 g dry matter (D.M.) to 1·6 g N/100 g D.M. for seed tubers obtained from crops grown at 0 and 201·301 kg N/ha. Seed of cv. Maris Peer from crops given 100 kg N/ha in 1969 produced ware yields 10% and 24% higher than those obtained from seed from crops given 0 and 201 kg N/ha. No effects of fertilizer applied to the seed crop on subsequent growth were observed in the other two experiments.

It is suggested that the effects of nitrogen fertilizer applied to the seed crop on subsequent growth other than that related to seed tuber size only arise as a result of effects on the maturity of the seed crop. Thus any observed effect is attributed to differences in the ‘physiological age’ of seed rather than to differences in seed tuber N-reserves.
The reproductive performance of two British breeds of sheep in contrasting photoperiodic environments
Authors: Williams H. Ll.
Published: March 2009

The reproductive performance of breeding and cyclic Welsh Mountain (WM) and Border Leicester (BL) ewes was compared in two contrasting photoperiodic environments during January 1971–April 1972. Treatment 1 consisted of natural daylength changes at latitude 51° 43’ N. There was no difference between the two breeds in onset of the breeding season, percentage exhibiting oestrus or percentage lambing. The breeding season of BL ewes terminated earlier (mean date, 31 January) than that of WM ewes (mean date, 9 March). The WM ewes had 8–12 oestrous periods and the BL ewes 7–11 oestrous periods. In treatment 2 a simulated equatorial photoperiod (13 h light: 11 h dark) was applied from January 1971 but was inadvertently interrupted by a short period of continuous light in June 1971. All WM ewes exhibited oestrus compared with 37·5% of BL ewes. The failure to show oestrus in the majority of BL ewes contributed to the marked difference between breeds in the percentage of ewes lambing: 88·9% in WM compared with 11·1% in BL ewes. In the cyclic subgroup, the WM ewes had 3–10 oestrous periods and the BL ewes, 2–7 oestrous periods.

It is concluded that the breeds showed a differential response to the two treatments and that Treatment 2 had a marked adverse effect on the reproductive potential of the Border Leicester ewes.
Contribution of legumes to the fertilizer nitrogen economy in a maize-based cropping system
Authors: Singh R. K. , De R. , Lal R. B.
Published: March 2009

A field experiment conducted for two cropping seasons (1976–7 and 1977–8) showed that a fodder crop of Egyptian clover (Trifolium alexandrinum) increased the grain yield of a subsequently grown maize crop. Lathyrus (Lathyrus sativus) and peas (Pisum sativum) were less effective in this regard.
Evaluation of the potency of the biological compound Dipel against the spiny bollworm Earias insulana (Boisd.)
Authors: Mesbah H. A.
Published: March 2009

Laboratory studies were conducted to evaluate the pathogenic effect of Dipel Bacillus thuringiensis separately, and in combination with sugar on the fourth instar larvae of spiny bollworm using both a dipping and a residue film method of application. In addition the histopathological changes in the treated mid-gut larvae are described.
Dietary phosphorus depletion in sheep: effects on plasma inorganic phosphorus, calcium, l,25-(OH)2-Vit.D3and alkaline phosphatase and on gastrointestinal P and Ga balances
Authors: Breves G. , Ross R. , Höller H.
Published: March 2009

Experiments were carried out to study the effects of dietary P depletion on plasma concentrations of inorganic P (P1), calcium, 1,25-(OH)2-Vit.D3and alkaline phosphatase, and to investigate the effects of P depletion, in comparison with P repletion, on intestinal flow and net disappearance of Ca and P in sheep. The animals were adapted to an experimental diet of pellets and chopped straw providing between 0·91 and 1·04 g P/day for depletion. They were repleted by single infusions of phosphate into the duodenum raising total P supply to about 4·1 g/day. During P depletion plasma P1, concentrations decreased significantly whereas those of Ca increased. The development of hypercalcaemia is discussed with respect to intestinal absorption and bone accretion and resorption. Plasma 1,25-(OH)2-Vit.D3and alkaline phosphatase were not affected by P depletion.

In P depletion the flow through the gastrointestinal tract of total P contained in the digesta and faecal P excretion were significantly reduced and the P balance was slightly negative. Calcium net absorption from the gut was also reduced. Daily flow of total P and P1, contained in the particle-free intestinal fluid was markedly lower in P depletion as compared with P repletion. The percentage of net disappearance from the small intestines of total P and P1, in the particle-free fluid was 57 and 70 % in the depleted state and 79 and 93% in the repleted state.
The effect of previous cropping and manuring on the yield of potatoes
Authors: Hanley F. , Ridgman W. J. , Jarvis R. H.
Published: March 2009

1. An experiment conducted on a light gravelly soil at Cambridge which compared the effects of different sequences of cropping, some of which contained leys of various types and duration, different levels of nitrogenous manuring, and the application of farm-yard manure on the yield of potatoes, is described and the results discussed.

2. Under the circumstances of the experiment, in which phosphate and potash were maintained at a high level on all plots, sequence of cropping had little effect on the yield of potatoes when 4 cwt./acre of ‘Nitro-Chalk’ was applied to the potatoes, but in the absence of applied nitrogen leys containing lucerne led to higher yields than other sequences.
The fleece of the Scottish Blackface sheep. IV. The effects of pregnancy, lactation and nutrition on seasonal wool production
Authors: Doney J. M.
Published: March 2009

Pre-mating, pregnancy and lactation periods correspond approximately with summer, winter and spring and any effects either of physiological status or nutritional conditions are confounded with the natural rhythm of wool growth. Within this framework, barren ewes produced slightly more wool than in-lamb ewes in winter and considerably more during the period of lactation. Improved nutrition during winter produced no increase in wool production, although it had a marked effect on live-weight maintenance. During lactation, improved nutrition resulted in an increase in wool production. The implications of the nutritional and seasonal rhythm of wool productions are discussed in relation to the adaptation of the breed to its environment.
Side-placing urea and other nitrogen fertilizers for spring barley
Authors: Widdowson F. V. , Penny A. , Williams R. J. B.
Published: March 2009

1. Laboratory experiments compared alternative ways of placing urea for wheat. Urea greatly increased the pH in the seed-row; placed in contact with seeds, it killed many plants, but did not when placed 1 in. to the side of the seed.

2. A combine-drill was modified so that, by simple adjustments, fertilizers could be placed in contact with the seed, or at 1 in. to the side of the seed, or broadcast over the seed-bed.

3. Fifteen experiments with spring barley and one with spring wheat, made from 1960–62, compared yields from urea with yields from ammonium sulphate; calcium nitrate and sodium nitrate were tested in seven and in six experiments, respectively.
Levels of first winter feeding in relation to performance of Cheviot hill ewes
Authors: Gunn R. G
Published: March 2009

1. Over 3 years, different levels of first winter nutrition created the following live-weight differences between groups of North and South Country Cheviot ewe hoggs at 12 months of age. High plane (H.P.) and mid-plane (M.P.) fed groups born 1956 were 34–35% and 11–13% heavier, respectively, than low plane (L.P.) fed groups, H.P. and M.P. fed groups born 1957 were 47–57% and 18–24% heavier, respectively, than hill-wintered groups. Away wintered groups born 1958 were 9–12% heavier than hill-wintered groups. All group differences were highly significant.

2. From 12 months onwards all groups were run together on the same hill and received similar management. Live weight and live measurement response of the total treatment groups and of the heavy and light hoggs within the groups prior to treatment were studied over the summer after treatment from 12 to 18 months.
The influence of N and Mg fertilizers and CaCO3 on the absorption of Mg by oats
Authors: Alston A. M.
Published: March 2009

The effects of applying CaCO3, MgSO4, 7H2O, (NH4)2SO4 and Ca(NO3)2 to the soil on the drymatter yield and Mg absorption of oats at the 4-5-leaf stage were studied in a factorial pot experiment with a Mg-deficient acid sandj soil.

Yield of dry matter was increased by all treatments, particularly CaCO3.

Applying CaCO3, MgSO4, 7H2O and Ca(NO3)3 generally increased % Mg and total Mg uptake of oats. Applying (NH4)2SO4, which reduced the % Mg in oats growing in the unlimed soil, generally increased % Mg where CaCO3 was also added. The rate of nitrification of NH4, which was slow in the acid soil, was greatly increased by applying CaCO3.
Respiration in cropped and fallow soil
Authors: Pritchard D. T. , Brown N. J.
Published: March 2009

Soil air was sampled daily at depths of 5, 10, 20 and 30 cm in fallow and cropped plots, which had either been rolled or cultivated. Carbon dioxide was measured by gas chromatography.

Carbon dioxide concentrations were greater in the cropped than in the fallow plots. The rolled plots were wetter than the cultivated plots and carbon dioxide concentrations were also greater.

In the fallow plots, carbon dioxide was correlated with soil temperature but variations in soil moisture content had little immediate effect.

In the cropped plots, temperature effects were overshadowed by the response to irrigation which immediately increased the carbon dioxide concentration. These increases were attributed to enhanced root respiration, rather than to restricted diffusion or increased microbial activity.
Nitrogen utilization of growing-finishing Barbados Blackbelly lambs
Authors: Osuji P. O. , Devers C.
Published: March 2009

Twelve 6–8 months old male Barbados Blackbelly lambs were used in a 4 × 4 latin square experiment with three replicates to study the utilization of diets made from local by-products and containing 64, 93, 125 or 143 g crude protein/kgD. M.

Both dry-matter (mean 750·1 g/day) and digestible-energy (mean 6·2 MJ DE/day) intakes, and their digestibility coefficients increased, though not significantly, with increasing dietary protein concentration. However, nitrogen digestibility, urinary-nitrogen output and nitrogen retention all increased significantly (P< 0·01) with increasing dietary protein concentration.

Metabolic faecal nitrogen and endogenous urinary nitrogen derived from the intercept of significant regressions of nitrogen intake against urine and faecal nitrogen outputs were 5·07 g/kg dry matter eaten and 3·46 g/day (0·35 kg W0·75) respectively. The diets had a mean biological value of 73·6%. The digestible crude protein requirements for maintenance were (g/day) 29·0, 38·4 and 26·6 when estimated from nitrogen retention, factorially and from live-weight performance respectively.
Lactation pattern in Scottish Blackface and East Friesland × Scottish Blackface cross-bred ewes
Authors: Peart J. N. , Doney J. M. , Smith W. F.
Published: March 2009

Milk yield of 2-year-old Scottish Blackface and of East Friesland × Scottish Blackface ewes rearing single or twin lambs was estimated by the oxytocin method on 1 day each week up to the 14th week of lactation. Both groups of ewes had been reared from birth under good nutritional conditions. They were housed in individual pens from mid-pregnancy and offered a liberal ration of a pelleted concentrate food until parturition. Similar food was offered ad libitum during lactation.

The cross-bred ewes rearing singles or twins produced significantly more milk in the first 12 weeks (181 and 258 kg respectively) than did pure Blackface ewes in the same period (144 and 208 kg respectively). The pattern of lactation differed between breeds. Cross-bred ewes attained higher maximum yields between the second and sixth weeks (2·37 and 3·32 kg/day, respectively, for single- and twin-suckled ewes) than did the Blackface ewes (1·97 and 2·88 kg/day). The yield from the cross-breds was sustained at a higher level throughout lactation. In the third 4-week period cross-bred ewes rearing single and twin lambs produced 116 and 92%, respectively, of their yield in the first 4 weeks whilst Blackface ewes produced 87 and 65%, respectively.

In the sixth week of lactation the milk produced by the two breed groups was similar in quality (mean value of solids-not-fat 11·04% and fat 5·48%) but by the 11th week the fat percentage of milk produced by Blackface ewes had increased significantly to 7·34% whereas that of the cross-breds had remained almost unchanged.

Single-suckled ewes gained weight throughout lactation but twin-suckled ewes remained relatively constant. Lambs reared as singles by cross-bred or Blackface ewes reached a mean live weight of 36·2 and 35·0 kg at 102 days of age, respectively, compared with 33·6 and 30·1 kg for twin lambs. Food intake of all ewes increased until the fifth or sixth week of lactation.
The effect of sodium hydroxide and urea on some storage properties of moist grain
Authors: Ørskov E. R. , Stewart C. S. , Greenhalgh J. F. D.
Published: March 2009

Storage of high moisture grain treated with NaOH in various concentrations and with and without urea showed that while untreated moist grain (17–26% moisture) deteriorated during storage, grain treated with urea and with various concentrations of NaOH had few bacteria and fungal propagules, and was considered safe for feeding. When the grain was treated with NaOH at 35 g/kg air dry weight, there were less than 102·6bacteria and fungal propagules/g. Similar results were obtained when grain was stored in large batches in an open shed, although at 20 g NaOH/kg grain there was some deterioration after 6 months.

Mouldy grain treated with NaOH showed an immediate decrease in both fungal propagules and bacteria from about 108to 104/g.

The possibility of using urea to preserve grain was examined in a 5 months storage trial with urea concentrations varying from 0 to 20 g/kg. With 5 g urea/kg grain there was an immediate decrease in the numbers of bacteria and fungal propagules and the results suggest that 10 g/kg would be safe for storage.

The mechanisms of the preservation effects of NaOH and urea are discussed.
Urea as a fertilizer. Ammonia evolution and brairding of wheat
Authors: Mees G. C. , Tomlinson T. E.
Published: March 2009

1. Moderate percentages of urea are widely and successfully used in compound fertilizers but the use of large proportions may be accompanied by two disadvantages:

(a) the loss of nitrogen as ammonia from surface applications,

(b) the occurrence of toxic effects when urea and seeds are drilled together in soil. This paper shows that both these effects are consequences of the rapid hydrolysis of urea to ammonia and carbon dioxide.

2. The effect on brairding of the presence of urea and of ammonium sulphate drilled with wheat seeds, and the loss of ammonia from top-dressings of the compounds on bare soils have been studied on a range of soils. Phytotoxicity was most pronounced in those conditions in which ammonia evolution was greatest. Thus, in a sandy soil, from which about 75% of the nitrogen of a top-dressing of urea was evolved as ammonia in our conditions, more than 15 lb. nitrogen as urea per acre reduced the braird of wheat seeds; while in a clay soil, from which only 10% of a top-dressing was lost as ammonia, up to 60 lb. nitrogen as urea per acre could be added before braird was reduced. Intermediate results were obtained with three more soils and ammonia evolution and brairding were always closely parallel.
The effect of date of winter grazing on the yield of a lucerne-grass ley
Authors: Hanley F. , Ridgman W. J. , Whitear J. D.
Published: March 2009

It has been shown that lucerne/grass mixtures, especially those containing a high proportion of cocksfoot, can make a valuable contribution to the winter feeding of livestock when the autumn growth is allowed to stand in the field until the winter. For instance, Hughes (1954) showed that it was possible to carry store cattle right through the winter on such herbage with little supplementary feeding. Other experimental work (Barker, Hanley & Ridgman, 1955) has shown that mowing or grazing this autumn growth in September may lead to poorer production in subsequent years than October defoliation. It therefore seemed desirable to determine the effect of date of grazing in the winter on the subsequent yield of a lucerne/grass ley and two experiments for this purpose were carried out at Cambridge from 1953 to 1957.
The digestion of frozen and dried grass by sheep
Authors: Beever D. E. , Thomson D. J. , Cammell S. B.
Published: March 2009

S. 24 perennial ryegrass, containing 2·9 g nitrogen/100 g D.M.>, was conserved by freezing (to represent the fresh material) or by drying. Three dehydration treatments were imposed, comprising low temperature (inlet temperature 145 °C) high temperature (inlet temperature 900 °C) or oven drying (100 °C for 18 h) and in addition part of the high temperature dried grass was treated with formalin (1 g/100 g crude protein) prior to feeding.

The digestion of the energy and nitrogen components of all diets was investigated using sheep fitted with re-entrant cannulae at the proximal duodenum and terminal ileum.

Dehydration and formalin of the grass reduced nitrogen solubility and apparent energy and nitrogen (P < 0·001) digestibilities but led to increased quantities of nitrogen entering the small intestine (P < 0·01) compared with the frozen diet. A significant relationship describing nitrogen transformations was established: Y = 165–1·13X (r = –0·98, P < 0·001), where Y is g nitrogen entering the small intestine per 100 g N consumed and X is dietary nitrogen solubility. All dried diets showed increased losses of nitrogen within the small intestine compared with the frozen diet, the largest values being observed on the oven-dried and formalin-treated diets.

Neither total VFA production within the rumen nor overall cellulose digestibility was influenced by dehydration, but on the formalin-treated diet there was a marked shift of cellulose digestion from the rumen to the caecum and colon compared with the other diets, associated presumably with the large reduction in protein solubility on this diet.

Dehydration improved the efficiency of conversion of ruminally digested energy to VFA energy within the rumen, and in relation to the nature of the total absorbed nutrients a significant relationship was established:

Y = 30·97–0·22X (r = –0·98; P < 0·001),

where Y is g digestible crude protein lost in the total intestines per 100 g digestible organic matter intake and X is dietary nitrogen solubility.
Heterosis, inbreeding depression and combining abilities in a five-parent diallel of six-row barley
Authors: Nasr H. G. , Khayrallah W.
Published: March 2009

The F1 and F2 generations of a diallel cross of six-row barley involving the parents, Beecher, Athenais, Atlas 46, 3130-4564-3, and 3130-864-4 were studied and heterosis, inbreeding depression, and combining abilities were measured for grain yield, number of tillers per plant, number of kernels per plant, kernel weight, and plant height. Significant heterosis was detected for grain yield in two of the ten crosses, for number of tillers per plant in one cross, for number of kernels per plant in two crosses, for plant height in three crosses, and for kernel weight in none of the crosses. The inbreeding depression of the F2 generation was present in most cases but significantly so in a few. Atlas 46 x 3130-4564-3 exhibited inbreeding depression for grain yield, number of kernels per plant, and plant height.

The general combining ability (GCA) mean squares of both generations were significant for all characters studied except number of kernels per plant in the F1 generation. The specific combining ability (SCA) mean squares were significant for only plant height in the F1 generation and all characters studied except number of tillers per plant in the F2 generation.

The GCA effects indicated that Beecher and Athenais are good general combiners for grain yield and its components. The latter parent produced good yielding hybrids with slightly shorter plants than the remaining hybrids.

The SCA effects revealed that Athenais × 3130-4564-3, Athenais × 3130-864-4, and Beecher × Atlas 46 seem good specific combinations for high grain yield. Also, the former two crosses tend to produce shorter plants.
The effect on soil conditions of mechanized cultivation at high moisture content and of loosening by hand digging
Authors: Gooderham P. T.
Published: March 2009

Untimely ploughing and rotavation of a silt loam soil was found to increase bulk density, and mechanical resistance to a needle penetrometer probe, and to reduce air porosity. These effects were not found deeper than 8 cm, although measurements with a 13 mm field penetrometer probe indicated some increase in mechanical resistance down to 30 cm. The effect of untimely cultivations on soil conditions was small when compared with the effect of loosening by hand digging. This treatment reduced substantially the bulk density and mechanical resistance; it increased air porosity and moisture content of the subsoil. Although measurements of mechanical resistance with the laboratory penetrometer were 2·4 times those of the field penetrometer, there was nevertheless good correlation between measurements.