bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of the nitrogen content of plant breeding material using a Carlo Erba Nitrogen Analyser
Authors: Starr Carol , Young Jacqueline , Smith D. B.
Published: March 2009

The measurement of the nitrogen (N) content of plant material, used as an assessment of protein concentration, is important in determining the quality of various crops for feeding and processing. The generally accepted reference procedure for the direct measurement of N is the Kjeldahl method (Horwitz, 1980), first introduced 100 years ago (Kjeldahl, 1883). Recently a number of alternative direct (Williams et al. 1978) and indirect (Starr, Morgan & Smith, 1981) methods have become available.
Establishment studies II. The effect of method of establishment on a 1 year ley in the seeding year
Authors: Charles Allen H.
Published: March 2009

The influence of undersowing on the establishment of broad red clover and Italian rye-grass was investigated under three managements and two levels of nitrogen applied in spring. The following conclusions are drawn:

1. The cereal cover crop reduced the aggressiveness of Italian rye-grass towards red clover.

2. The cereal cover crop produced a high initial yield of dry matter and crude protein. In midseason, when keep from maiden seeds is important, the highest yield was obtained in the absence of the cereal cover crop.

3. The danger of failure in the take of undersown herbage seeds is increased when soil moisture is very low.

4. Total dry-matter yield in the seeding year was increased by using a cover crop, but starch-equivalent yield was not greatly affected. Crude-protein production was increased when the cover crop was cut for silage or frequently grazed, but not when a grain crop was harvested.

5. Undersowing Italian rye-grass and clover gave a higher yield of dry matter, starch equivalent and crude protein than sowing the herbage after the cereal was harvested.

6. The cover crop depressed weed growth, and ‘Nitro-Chalk’ increased it, except where Italian rye-grass was undersown.

7. The application of ‘Nitro-Chalk’ increased the yield of dry matter, particularly early in the seeding year. ‘Nitro-Chalk’ encouraged the growth of Italian rye-grass and oats but depressed the clover. This reduction in legume yield was least when defoliation was frequent. The influence of nitrogen on plant growth was especially noticeable when soil moisture was low and a cover crop used.
The functional development of the calf II. Development of rumen function in the calf
Authors: Godfrey N. W.
Published: March 2009

1. Two experiments were conducted to study the development of rumen function in young dairy calves under different feeding regimes.

2. The volume of the rumen contents increased with age whereas the volume of the abomasum contents tended to remain constant.

3. The concentration of total volatile fatty acids in the rumen liquor of milk-fed calves with free access to pasture reached constant levels at 5 weeks of age. Restricting calves to an all milk diet delayed the development of adult levels of volatile fatty acids until such time as roughage became available.

4. Levels of rumen ammonia were high soon after birth but showed a decline with age. An absence of roughage in the diet tended to maintain higher levels of rumen ammonia.

5. The pH of rumen liquor showed a steady increase from birth to 17 weeks of age.

6. Both volatile fatty acid and ammonia levels in the rumen showed a characteristic diurnal pattern of variation.

7. High figures for the digestibility of pasture by young calves were obtained. When calves which had been restricted to an all milk diet were offered roughage they quickly attained a digestive efficiency comparable with calves which had access to pasture from birth.
Studies on the effect of humidity on the hatchability of hens' eggs II. A comparison of hatchability, weight loss and embryonic growth in eggs incubated at 40 and 70% R.H.
Authors: Robertson I. S.
Published: March 2009

Eggs from Light Sussex hens were weighed before incubation started and on the 19th day of incubation to determine weight loss when incubated at 40% B.H. compared with 70% R.H. They were allowed to hatch and the day-old chicks were weighed.

Although the eggs incubated in the drier atmosphere lost more weight, their hatchability was no less than the eggs incubated in the wetter atmosphere. The hatched live weight of the chicks from the respective groups did not differ significantly.

The comparatively good hatch obtained here and in part I at the 40% R.H. is suggested as being an indication that for optimum hatchability large eggs may require lower humidity than small eggs.
Factors influencing the role of clover in grass-clover leys fertilized with nitrogen at different rates III. The effects of the variety of companion grass and of the variety of clover on the botanical composition of the sward
Authors: Reid D.
Published: March 2009

1. In an experiment designed to study some of the factors influencing the role of clover in grassclover swards fertilized with nitrogen at different rates, botanical studies of the sward were made each spring and autumn. The methods used, and the results obtained in the autumn studies, are described in this paper.

2. Full details of the experimental treatments and design, and the yield results have been reported previously.

3. The botanical composition of the sward depended to a far greater extent on the variety of grass than it did on the variety of clover included in the seeds mixture. This was true also of the yields from the different swards.

4. Some relationships are suggested between the yield and nitrogen response results and the variations in the botanical composition of the sward attributable to the variety of grass included in the seeds mixture.

5. Kersey white clover appeared to be more persistent than S. 184 and S. 100 where fertilizer nitrogen was applied to the sward, although no differences in persistency were noted in the absence of applied nitrogen.

6. A statistical study of the botanical data obtained indicated that the intensity of sampling employed gave the optimum balance between variance and time expenditure, since only a slight reduction in variance would have been obtained if double the number of samples had been taken.
Urea as a fertilizer
Authors: Templeman W. G.
Published: March 2009

The results of the grassland experiments show that as a straight nitrogen fertilizer urea was, on average, slightly less effective than the conventional materials. In the majority of individual experiments there was no significant difference between the yields from urea and those from ‘Nitro-Chalk’; on the other hand, in a very few experiments the urea yields were much lower. The arithmetic means of the averages in each series of grassland experiments indicate that urea gave total yields about 93% of those from ‘Nitro-Chalk’ and the average response (i.e. difference from control) from urea was about 85% of that from ‘Nitro-Chalk’.

The available data for cereals are considerably less than for grassland but here again there is an indication of the infrequent slightly lower efficiency of urea.

On kale the results are confusing. At times urea was safe but in one experiment heavy dressings incorporated in the seed-bed caused serious damage.
An intensive cereal-growing experiment
Authors: Hood A. E. M. , Procter John
Published: March 2009

1. An experiment was conducted at Jealott's Hill from 1945 to 1956 to study yield trends of cereals grown continuously and in four-course rotations including 1-year ‘renovation’ treatments in the form of (a) grazed ley, (b) ley cut for hay and grazed, (c) rape grazed, (d) mustard for green manure, (e) fallow.

Winter wheat, spring oats and spring barley were successive test crops common to all rotations and followed the ‘renovations’ or spring barley in the corresponding phase of the continuous cereals system. Main plot (rotation) comparisons were confounded with two levels of nitrogen fertilizer (0·2 and 0·4 cwt. N/acre) and three straw treatments (straw removed, burned or ploughed in) which were applied to all three cereal test crops.

All plots except those in fallow received 0·3 cwt. P2O5 and 0·3 cwt. K2O/acre every year. From 1945–48, leys, rape and mustard received 0·2cwt. fertilizer N/acre; from 1949 this dressing was doubled.

Grazing of leys and rape was by sheep.

2. In the earlier years the highest yields of wheat were obtained in the rotations containing rape, mustard or fallow, but in the later years yields after leys were superior to those in all other rotations. Wheat yields in the continuous cereals rotation soon declined and remained at the lowest level throughout, due largely to severe incidence of ‘take-all’ disease.

In the later years yields of barley and oats following 1-year ley were also superior to those in all other rotations.

3. In the six cropping rotations compared, all three cereal crops showed very marked responses to applied fertilizer nitrogen, particularly in the later years as the natural fertility of the site declined.
The development of the digestive system of the young animal V. The development of rumen function in the young lamb
Authors: Walker D. M. , Walker Gwen J.
Published: March 2009

1. A total of twenty-one Merino lambs varying in age from 2 to 11 weeks were slaughtered.

2. The enzymic activity of their rumen contents was measured on a variety of carbohydrates and on protein.

3. Enzymic activity was expressed as mg. carbohydrate hydrolysed/mg. protein nitrogen/hour.

4. When compared with the rumen contents of adult sheep, lactase and proteolytic activity decreased with age; maltase, sucrase and fructanase activity increased; amylase activity decreased from 2 to 11 weeks though adult values were similar to those of the 2-week-old lamb.

5. The rumen contents of the lamb were as efficient as those of the adult sheep in their ability to hydrolyse a wide variety of carbohydrates and protein.
Growth and development in the pig, with special reference to carcass quality characters: Part IV. The use of sample joints and of carcass measurements as indices of the composition of the bacon pig: Part V. The bearing of the main principles emerging upon the many problems of animal production and human development
Authors: McMeekan C. P.
Published: March 2009

1. The accurate measurement of the amount of bone, muscle and fat in the bodies of meat animals is of considerable importance in all technical studies relating to carcass quality. Chemical analysis and laboratory dissection of complete animals are associated with disadvantages which preclude their extensive use. Material derived from nutritional experiments has provided the opportunity for statistical investigation of the possibility of using sample joints and carcass measurements as indices of the composition of bacon pigs of 200 lb. live weight. The extent and nature of the variation in the composition of the pigs concerned adds to the significance of the results obtained.

2. The total weight of bone, muscle and fat in the bacon-pig carcass can be estimated with a high degree of accuracy from the respective weights of these tissues in either the loin or the leg. The combination of these two joints provide even higher correlations in each case than either one alone. In all cases the correlation coefficients approach unity and are strongly significant at the 1% point. For the combined joints the values ofrfor bone, muscle and fat respectively are +0·9444, + 0·9765 and +0·9750. Regression functions have been developed for the purpose of estimating carcass composition from these joints.
Diurnal variations in number of ciliate protozoa in the rumen of sheep fed once and twice daily
Authors: Michalowski T. , Muszyński P.
Published: March 2009

Diurnal changes in number of protozoa were examined in two wethers fed once and twice daily with 0·4 kg of concentrate and 0·4 kg of hay per day. The number of protozoa varied from 4·8 × 105 to 12·5 × 105 cells/ml of rumen fluid, depending on the feeding frequency and time of the day.Entodiniaformed 96·3%,Holotricha2·0%,Diplodinia1·3%, andOphryoscolex0·4% of the total counts. All taxonomic groups of protozoa reached maximum concentration immediately before feeding and decreased by about 60·80% during 4·12 h after feeding. Larger decreases occurred in animals fed once daily.

Rumen fluid volume varied from 3·12 to 4·47 l but in different ways due to feeding frequency. Diurnal patterns of dilution rate of rumen fluid were the same in animals fed once and twice daily, showing the decrease from 0·98 1/h at 09·00 h to 0·311/h at 01·00 h. It is suggested that some factors other than dilution rate may be responsible for the decrease of protozoa after feeding.
Yield, seasonal changes in root competitive ability and competition for nutrients among grass species
Authors: Remison S. U. , Snaydon R. W.
Published: March 2009

Root interactions between populations ofLolium perenne, Dactylis glomerata, Holcus lanatus and Anthoxanthum odoratumcollected from fertilized and unfertilized plots of the Park Grass Experiment were investigated at two levels of NPK over a period of 3 years.

The root competitive abilities of species were dependent on fertilizer applications and changed with time. For example,L. perennewas more competitive at high nutrient application and during the early stages of the experiment. On the other hand, the root competitive ability of H. lanatus was greatest on unfertilized soil and increased with time. The large effect of root interaction on plant yield and the effects of fertilizer application on this, may be regarded as evidence of competition for one or more of the elements, N, P and K. H. lanatus, the most aggressive species, was more competitive on the unfertilized soil (NIL) than on the fertilized soil (NPK). However, this could not be confirmed by chemical analysis of plant material; there was no conclusive evidence that aggressive species contained higher concentrations of these nutrients when grown in mixtures with less aggressive species. The possibility of allelopathy, the production of toxins by one plant which inhibit the growth of another, cannot be precluded.

The root competitive ability of species and populations was not positively correlated with the yield of species and populations in pure stand. Indeed, negative correlation was found especially on unfertilized soil. In this case varieties or species with a low yield in pure stand were highly successful root competitors in mixtures, while those with high yield in pure culture were poor root competitors.
A comparison of two non-radioactive digesta marker systems for the measurement of nutrient flow at the proximal duodenum of calves
Authors: Beever D. E. , Kellaway R. C. , Thomson D. J. , MacRae J. C. , Evans C. C. , Wallace Annie S.
Published: March 2009

The use of non-radioactive ruthenium phenanthroline (Ru-P) and chromium EDTA (Cr-EDTA) as dual phase markers of digesta flow was examined and compared with chromium sesquioxide (Cr2O3) in conjunction with spot samples of digesta collected from T-shaped cannulae situated in the proximal duodenum of weaned calves.

In vitro estimates of organic matter digestibility indicated that on a cubed barley diet, Ru-P exhibited toxic effects at concentrations on 2·2 × 10–5 M and above. No such effects were noted with Cr-EDTA. Subsequently satisfactory infusion rates of 12 mg Ru and 280 mg Cr/kg dry-matter intake were established.

Daily flows of organic matter, starch, nitrogen, fibre, sodium and potassium at the proximal duodenum were calculated by the dual phase marker system and by Cr2O3, and regression equations relating these two for each dietary component were calculated. Examination of the intercepts revealed that they all differed significantly from zero (P < 0·05) whilst all the regression coefficients were significantly different from unity (P < 0·05), thus indicating that Cr2O3 underestimated nutrient flows at low flow rates and overestimated them at high flow rates relative to the corresponding estimates based on Ru-P plus Cr-EDTA.
Liquid manure as a grassland fertilizer. III. The effect of liquid manure on the yield and botanical composition of pasture, and its interaction with nitrogen, phosphate and potash fertilizers
Authors: Drysdale A. D.
Published: March 2009

1. In an experiment conducted for the 3 years 1961-63 on a perennial rye-grass and white clover sward a split-plot design was used to investigate the effects of liquid manure (cow urine + water) and its interactions with various levels of nitrogen, phosphate and potash fertilizers on the yield of herbage and on the botanical composition of the sward.

2. On the average the liquid manure contained 0.26% N, 0.44% K and had a pH of 8.6.

3. The liquid manure treatments supplied 0, 50, 100, 200 and 400 lb. N/acre/year and 0, 87, 174, 349 and 697lb. K/acre/year. The fertilizer nitrogen treatments were 0, 100 and 200lb. N/acre; the potash treatments 0 and 166 lb. P/acre and the phosphate treatments 0 and 66lb. P/acre.
Post-harvest changes in seed ofLoliumspecies
Authors: Stoddart J. L.
Published: March 2009

1. The point at which continued development of a seed no longer depends upon attachment of the culm to the root system can be termed rootindependence.

2. Serially harvested inflorescences ofLolium temidentumL. were maintained in a glasshouse under the same environmental conditions as standing material. Samples for analysis were taken from harvests and standing material at 2 days intervals to compare chemical changes occurring in seed on standing and severed culms. Analyses for total soluble carbohydrate (T.S.C.) were performed on a single seed basis.

3. Harvests made before the seed T.S.C. maximum resulted in oscillating changes in endosperm free sugar content and these caryopses tended to stabilize at an excessively high value. All later harvests resulted in seed with a final T.S.C. level within 1% of that present in normally matured seed

4.14C-Sucrose uptake studies showed that tho endosperm T.S.C. requirement was high prior to the seed T.S.C. maximum but that it was very low during the second half of the maturation sequence. It is considered that during this period sugar is only translocated to make good respiratory losses.
Some aspects of the utilization of tropical forages. 2. Pangola and coastal Bermuda hays
Authors: Butterworth M. H. , Butterworth Juanita P.
Published: March 2009

1. Three hays of Coastal Bermuda (Oynodon dactylon) grass and three hays of Pangola grass (Digitaria decumbens) from grasses cut at different stages of maturity were used for the determination of digestibility coefficients, voluntary intake, rate of passage through the gut, production of total and individual volatile fatty acids, total counts of bacteria determined microscopically and examination of bacterial types present using Gram-stained smears. The animals used were individually housed sheep.

2. The hays of Coastal Bermuda were significantly superior to those of Pangola from the point of view of digestibility. Significant differences did not exist within grasses.

3. The hays of Coastal Bermuda were superior to those of Pangola from the point of view of intake although this was not significant.

4. No relation was evident between digestibility of the various hays and rate of passage through the digestive tract; it was concluded that intake was not limited by rate of passage through the gut.
Selection criteria in grass breeding. VI. Effects of defoliation on plants growing in small plots in field and controlled environment conditions
Authors: Lazenby Alec , Rogers H. H.
Published: March 2009

1. This paper reports on two experiments, one conducted in the field, the other in a cold cabinet. These had three objectives: (i) to examine the effects, on yield and some components of yield in certain grass varieties, of various combinations of frequency and intensity of defoliation, (ii) to compare these effects in the two environments, and (iii) to assess the value of very small plots.

2. Records were taken of the major environmental variables in the field; the chosen environment in the cabinet was quantified.

3. In the field trial, the cutting treatments comprised all combinations of two frequencies (herbage cut when 8 in. and 4 in. in length) and two intensities (cut back to tiller lengths of 2 in. and 1 in.) plus a fifth treatment of cutting at a silage stage back to a tiller length of 1 in. The first four treatments were also used in the cold cabinet trial. S170 and North African tall fescue were common to both experiments; in addition, S22 Italian rye-graes was included in the field trial. In both trials, plots consisted of four rows of seven plants, square planted at 2 in. x 2 in.
Release of non-exchangeable potassium from some British soils cropped in the glasshouse
Authors: Arnold P. W. , Close B. M.
Published: March 2009

1. Continuous cropping with perennial ryegrass in the glasshouse was used to measure the release of non-exchangeable potassium from twenty soils representative of a wide variety of soil series.

2. Releases of non-exchangeable potassium ranged from almost none to > 2000 lb. K/acre.

3. The main reason for the variations in the potassium-releasing powers of the soils was traced to differences in the amount and potassium content of the finer clay fractions. Small potassiumcontents in the fine clay and small contents of fine clay were associated with small releases of nonexchangeable potassium.

4. Accumulated potash fertilizer residues or the presence of such minerals as glauconite can be responsible for the good potassium-releasing powers of some soils.

5. Some of the limitations of glasshouse work for assessing the potash status of soils are discussed.

6. Evidence was obtained for the existence in many soils of at least two categories of useful nonexchangeable potassium.
Studies on the gestation period and post-partum heat of Friesian cattle in Egypt
Authors: Dessouky F. I. , Rakha A. H.
Published: March 2009

1. The average length of gestation in Friesian cattle under Egyptian conditions was found to be 282·28 ± 10·7 days.

2. Neither the sex of the newborn calf nor the season of the year affects the gestation period significantly.

3. The average interval between calving and the first post-partum heat was found to be 85·52 ± 2·15 days.

4. The sex of the newborn calf does not affect significantly the interval of heat after calving whereas the month and the season of the year of calving affect this interval significantly.
The early weaning of pigs VII. The effect of level and source of protein in the diet of pigs weaned at 10 lb. live weight on subsequent performance and carcass quality
Authors: Blair R.
Published: March 2009

1. Dry-meal diets based on whitefish meal or soyabean oil meal, balanced in respect of minerals, and containing 28, 23 or 18% crude protein were given to pigs from 10 to 25 lb., and similar diets containing 18% crude protein were given from 25 to 40 lb. From 40 to 100 lb. and from 100 lb. to bacon weight all pigs were given the same diets with 16% crude protein and 14% crude protein, respectively.

2. From 10 to 25 lb. live weight the results showed that:

(a) With diets based on whitefish meal there was an improvement in growth rate of 11% (P < 0·05) and an improvement in feed conversion efficiency of 14% (P < 0·001) when the level of crude protein was increased from 18% to 23%. Growth rate and feed conversion efficiency were not improved further by increasing the level of crude protein from 23 to 28%.

(b) With diets based on soyabean oil meal, feed conversion efficiency and growth rate were not improved by increasing the protein in the diet from 18 to 23%, and performance was similar to that on the 18% protein diet based on whitefish meal. Pigs fed on the soyabean diet containing 28% protein were unthrifty and grew very slowly; some showed gastric ulceration.

(c) Consumption of the diets containing 18% crude protein was 8% higher (P < 0·05) than consumption of the other diets.

(d) Apparent digestibility of the dry matter of the diets, as measured by the chromic oxide marker method, rose as the pigs grew older, and apparent digestibility of the dry matter and crude protein of the diets based on soyabean oil meal was consistently lower than when whitefish meal was the main supplementary source of protein.
Study of long-term rotation effects in the Sudan Gezira
Authors: Roy D. K. Dutta , Kordofani A. Y.
Published: March 2009

The exhausting effect of dura for a single year in a rotation was shown. Rotations including dura consistently yielded less than those including lubia or fallow. With 2 successive years of dura the reduction in yields of cotton was extremely large.

Substantial increases in yields of cotton were obtained when the first fallow of the CFF rotation was replaced by lubia. The superiority of the rotation CLF appeared to be firmly established in the Gezira, where the soil was known to be deficient in nitrogen. By growing lubia, instead of leaving a fallow 2 years preceding cotton, an average annual increase of 0·65 k.p.f. of cotton was obtained. Itwas interesting to note that fertility of rotation CLF over CFF was still increasing.
The relative uptake of phosphorus by crops and natural fallow from different parts of their root zone
Authors: Nye P. H. , Foster W. N. M.
Published: March 2009

A tracer method has been used to determine the relative amounts of phosphorus that a range of short-term crops and fallows derive from different parts of their root zone when growing on a phosphorus deficient latosol. The short-term crops made little use of sub-soil phosphorus: millet derived 16% from below 12 in. after 95 days growth; and maize derived 7% and pigeon pea 11% from below 10 in. after 80 days. Pigeon pea feeds much closer to its base than the cereals until the 50th day. Since millet absorbed little phosphorus from subsoil placed in a layer only 5–10 in. deep, it is concluded that the poor uptake of subsoil phosphorus is due to low availability, rather than a natural surface feeding habit.

Pigeon pea in its second year extracted little more phosphorus from the subsoil than it did in the first. On the other hand, in a natural savanna both the perennial grasses and the associated dicots derived over 30% of their phosphorus from below the 10 in. layer. The amount corresponded with the proportion of dicotyledonous roots in the subsoil, but exceeded the corresponding proportion of grass roots. The greater proportion of subsoil phosphorus in the savanna may be due to lower availability of phosphorus in the topsoil, which in contrast to the other plots did not receive fertilizer.
The use of chromium oxide and lignin as indicators for the purpose of determining intake and digestibility of mixed rations by beef steers
Authors: Luitingh H. C.
Published: March 2009

During the winter of 1956, an experiment was conducted, using seventy beef steers of three different age-groups to determine intake and digestibility, by means of the indicator method, of mixed rations differing in ration concentration.

In the first part of the experiment, six pairs of steers of three age-groups receiving two types of rations were used. The pairs were selected on the basis of their rate of gain and constituted the fastest and slowest gaining steers of their respective age and ration groups. The object of the experiment was to ascertain whether any correlation could be found between the rate of gain of the steers and the degree to which the ration was digested.

Two indicators were used, namely, the internal indicator lignin and Cr2O3, administered twice daily by means of gelatin capsules, containing 7·5 g. of the indicator.

Using lignin as an indicator of digestibility, it was found that the calculated digestibility coefficient of both rations varied. A larger variation occurred, however, in the case of the ration with a concentrate to roughage ratio of 2:1 than in the case of the ration with a ratio of 1:3·6.
Experiments with nitrogen and potash on barley
Authors: Widdowson F. V. , Penny A. , Williams R. J. B.
Published: March 2009

1. Four experiments in 1958 and five in 1959 compared responses to potassium (as combinedrilled muriate of potash) in the absence of nitrogen and in the presence of single and double doses of nitrogen (as broadcast sulphate of ammonia) on soils selected because they contained very little acid-soluble potassium.

2. Responses to 0·5 cwt. K2O/acre were obtained at six centres (two significant), but the effects of a further 0·5 cwt. K2O/acre were more variable and gains and losses (each at four centres) were almost equally balanced.

3. Gains from nitrogen were associated with previous cropping. N1 raised yields at seven centres (six significantly), but N2 raised yields further at only five centres (three significantly) and depressed yields significantly at three centres where barley followed a root crop or ley.

4. Potash did little to improve the strength of straw and therefore standing capacity in a wet season (1958) and had little effect upon the size of the grain, whereas nitrogen increased lodging and reduced the average size of the grain.

5. Increases in potassium uptake were associated with yield increases, whereas increases in nitrogen uptake were associated with both higher nitrogen percentage in grain and higher yields.
The influence of turning on the hatchability of hens' eggs II. The effect of turning frequency on the pattern of mortality, the incidence of malpositions, malformations and dead embryos with no somatic abnormality
Authors: Robertson I. S.
Published: March 2009

Reasons were sought for the changes in hatchability associated with varying frequency rate observed in part I and by other workers. All deadin-shell from the hatches of part I were examined and classified into a number of categories. Their varying incidence in relation to the control hatches was taken to indicate the effect of the rates of turning investigated, viz. 0, once in 2 days, 2, 6, 12, 24 (control), 48, 96, 144, 192 and 480 turns per 24 hr. to the end of the 18th day of incubation.

At the observed optimum rate of turning (96x) mortality was reduced throughout the incubation period with the greatest reduction occurring towards the end; the incidence of malpositions and malformations was reduced as was the case of embryos with no obvious cause of death.

The observed decrease in mortality and hence increase in hatchability at the optimum rate of turning was attributed mainly to the probable improvement of the embryo's physiological environment.
The effects of supplemental detergents on the digestibility of poultry diets
Authors: Bolton W.
Published: March 2009

1. The effects of the addition of a non-ionic, anionic or cationic detergent to a diet containing 10% added fat on the digestibility of the protein, fat and carbohydrate have been studied.

2. The non-ionic detergent aided the digestion of fat, but protein and carbohydrate digestibility were unaffected.

3. An anionic detergent slightly, and a cationic detergent seriously, impaired the absorption of fat, and the cationic detergent also had an adverse effect on carbohydrate digestion. Neither affected protein digestion.
Some effects of nutrition on the growth and sexual development of ewe lambs
Authors: Allen D. M. , Lamming G. E.
Published: March 2009

1. In the seasons of 1957 and 1958–59 a total of 130 ewe lambs were used to investigate the effects on growth and sexual development of high and moderate planes of nutrition during the rearing period.

2. The nutritional treatments imposed had significant effects on rate of growth; puberty occurred at an earlier age in high-plane than in moderateplane lambs. Also, in 1958–59, four moderateplane lambs failed to exhibit oestrus during their first winter of life.

3. Puberty occurred at a significantly lower live weight in moderate-plane than in high-plane lambs.

4. In lambs slaughtered after first oestrus, ovulation rate was not significantly affected by nutritional level, nor was the number of ovarian follicles greater than 2 mm. in diameter. However, high-plane lambs tended to have more follicles less than 2 mm. in diameter than moderate-plane lambs.

5. In 1958–59 the ovarian response to a subcutaneous injection of 800 i.u. of p.m.s. was investigated in half the lambs from each nutritional treatment. Injections of p.m.s. caused a marked increase in ovulation rate over the uninjected control level but there was no difference in response between nutritional treatments. Pregnant mare's serum did not alter the size distribution of ovarian follicles.
The effect of feeding on the concentration of glucose and insulin in the portal and atrial plasma in pigs
Authors: Anderson D. M.
Published: March 2009

Pigs weighing 25–40 kg were fed either once or twice per day and glucose and insulin concentration in portal and right atrial plasma measured during a 24-h cycle. Feeding resulted in an immediate increase in both portal and atrial glucose concentration. Portal glucose concentration tended to show cyclical changes with the peaks ascending and descending progressively. Under both feeding treatments glucose was absorbed from the gut for 18–20 h/day. Feeding of pure starch resulted in a rise in portal plasma glucose concentration within 10 min, but feeding of pure casein had no effect.

Portal insulin concentration increased immediately on feeding as did atrial insulin concentration, and under both feeding treatments portal and atrial insulin concentration followed a pattern similar to the corresponding glucose concentration. Feeding of pure casein was without effect on the concentration of insulin in either portal or atrial plasma.
The effect of level of water intake on some aspects of digestion and nitrogen metabolism of the ‘desert sheep’ of the Sudan
Authors: Osman H. Elsayed , Fadlalla B.
Published: March 2009

Five successive trials were conducted using eight adult rams (Sudan desert sheep) to study the effect of restriction of water intake on some aspects of digestion and nitrogen metabolism. The feeds used in this study were berseem hay (Medicago sativa), lubia hay (Dolichos lablab), maize hay (Zea mais), a concentrate mixture, and dry desert grasses (hummra) (a mixture ofDactyloctenium aegyptium, Schoenefeldia gracilis, Eragrostis pilosa, Aristida funiculataandAristidaspp.).

Restriction of water did not affect the digestibility coefficients of organic matter, crude protein and crude fibre significantly. The digestibility coefficient of ether extract was significantly reduced whereas that of nitrogen-free extract was slightly higher when water was restricted.

The concentrations of ammonia and volatile fatty acids in the rumen and of urea in the blood were recorded before and 3 h after feeding. Increases in rumen ammonia and blood urea nitrogen concentration were reduced by water restriction except when hummra was fed.

Restriction of water intake also slightly increased thein vitrorate of fermentation of rumen contents which is taken as a measure of microbial activity in the rumen, and the retention of nitrogen. These results are interpreted as indications of more efficient nitrogen utilization under conditions of water restriction.

There were no significant effects of the treatments on changes in the concentration of volatile fatty acids.

The significance of these findings in relation to the management of desert sheep in the arid parts of the Sudan is discussed with special reference to the effect of the level of dry-matter intake on nitrogen balance.
Glucose and fatty acid metabolism in cows producing milk of low fat content
Authors: Annison E. F. , Bickerstaffe R. , Linzell J. L.
Published: March 2009

The effects of changing to a high starch: low roughage diet have been studied in two Friesian and two Jersey cows, surgically prepared for the simultaneous study of udder metabolism (arteriovenous difference x udder blood flow) and whole body turnover of milk precursors (isotope dilution).

In the Friesian cows milk fat concentration was lower on the high starch diet but in the Jerseys fell only slightly in one animal. In both Friesians and in the one Jersey these changes were accompanied by an increase in total rumen VFA concentration. Rumen acetate concentration did not change but propionate doubled. Thus this confirms that the usually reported fall in ‘acetate:propionate ratio’ is due to a rise in propionate production rather than due to a fall in acetate production.

There were significant falls in the blood concentrations of acetate and β-hydroxy-butyrate. The rate of extraction by the udder of acetate and β-hydroxybutyrate did not change but triglyceride extraction fell. Therefore since udder blood flow did not alter the uptake of all three fat precursors fell.

The entry rate of glucose into the circulation and its contribution to total body CO2 increased. The entry rate and contribution to CO2 of acetate decreased but this was probably mainly due to a fall in endogenous acetate production by the body tissues. Plasma FFA concentration showed little change but the entry rate of palmitate fell on the high starch diet. There was also an increased proportion of unsaturated and trans fatty acids in the plasma and milk triglycerides.
Variation in plasma glucose and free fatty acid concentrations in sheep associated with season, pregnancy and lactation
Authors: Leat W. M. F.
Published: March 2009

Plasma free fatty acid (FFA) concentrations are generally a reflexion of the extent of mobilization of depot fats (Frederickson & Gordon, 1958). In non-fasted sheep values are low, usually in the region of 100–200 μ-equiv./litre plasma, but occasionally values up to 500 μ-equiv./litre have been noted in fed, unstressed sheep (Leat & Ford, 1966). To obtain information on the variation in the concentration of plasma glucose and FFA, sheep were studied over a period of two seasons.
The genetic control of erythrocyte reduced glutathione in Australian Merino sheep
Authors: Board P. G. , Roberts J. , Evans J. V.
Published: March 2009

The genetic control of the level of reduced glutathione (GSH) in the erythrocytes of pure bred Australian Merino sheep has been investigated. The data suggest that the erythrocyte GSH levels are in part controlled by a single pair of autosomal alleles, the gene for GSH-high (GSHH) being dominant.

The data also suggest that the levels of erythrocyte GSH within the GSH-high and GSH-low types are the result of polygenic influences. Heritability estimates of 0·7 and 0·5 within the GSH-high type and 1·2 in the GSH-low type support this suggestion.
The response to various pollination treatments in inbred lines of horse and tick beans (Vicia faba L.)
Authors: Toynbee-Clarke Gillian
Published: March 2009

Fourth and fifth generation inbred lines of horse and tick spring beans were used for pollination studies.

Treatments included tripping; emasculation followed by self- or cross-pollination at both the bud and mature flower stage; self-pollen rubbed on to the stigma; and the flower truss left undisturbed. Treatment means showed that there was no significant difference between leaving the flower truss undisturbed and tripping, but all other treatments differed significantly (P = 0·01) from these two. There was no difference in number of seeds set per flower between self- or cross-pollination following emasculation.

Tick inbred lines set more seeds per flower over all treatments than horse inbreds. Differences were seen between tick and horse inbreds when the flower truss was left undisturbed; some tick inbreds set seed, but no seed was set on the horse inbreds. An association between seed size and autofertility is suggested.

Results from the horse inbreds were in agreement with previous pollination studies on inbred lines of winter beans. The implications of these studies to plant breeding are discussed.
Growth and yield of lowland tropical maize in Mexico
Authors: Goldsworthy P. R. , Palmer A. F. E. , Sperling D. W.
Published: March 2009

The growth and yield of three tropical varieties of maize were studied at two elevations in Mexico: Poza Rica (60m) and Tlaltizapan (940m). Grain yields were between 3·5 and 8·5 t/ha. The growing period was longer and the crop produced more dry weight and yield at Tlaltizapan than at Poza Rica. Crop growth rates (C) increased to a maximum of about 35 g/m2/day at both sites and then declined. Grain growth rates (maximum 35 g/m2/day) exceeded current C during most of the grain filling period. After silking when C exceeded grain growth, dry matter accumulated in the stem. Later as grain growth increased and exceeded C, some of the accumulated material was incorporated into the grain and stem weight decreased. The dry weight increase after flowering was similar at the two sites, but the grain yield at Tlaltiapan was larger because a larger proportion of the dry weight increase was incorporated into the grain than at Poza Rica. The results indicate that at both sites grain ‘sink’ capacity was limiting yield.
The response of key gluconeogenic enzymes in bovine liver to various dietary and hormonal regimes
Authors: Baird G. D. , Young Janice L.
Published: March 2009

The effects of starvation, glucocorticoid administration, and the feeding of an all-concentrate diet, on the 14CO2-fixing activities of pyruvate carboxylase (EC. 6.4.1.1), phosphopyruvate carboxylase (EC. 4.1.1.32) and propiony1-CoA carboxylase (EC. 6.4.1.3) were measured in liver from lactating cows. Starvation caused a 26% decrease in propiony1-CoA carboxylase activity, glucocorticoid administration a 35% decrease in phosphopyruvate carboxylase activity, and the all-concentrate diet 24 and 41% increases in the activities of phosphopyruvate carboxylase and propiony1-CoA carboxylase respectively.
Calcium absorption during lactation in sheep with demineralized skeletons
Authors: Sykes A. R. , Dingwall R. A.
Published: March 2009

Of a group of 24 pregnant Scottish Blackface sheep 12 were killed at the outset and the remainder offered,ad libitum, a poor quality hay. At the end of pregnancy seven more were killed and the remainder offered, during lactation, 3 kg/head/day of a semipurified diet of 64% dry-matter (D.M.) digestibility, and containing 18% crude protein (CP), 1·17% Ca and 0·82% P in the D.M. Milk production was determined at weekly intervals and milk samples obtained at these times for estimation of Ca and P concentrations. These sheep were killed 42 dayspost-partum. The shorn empty bodies were analysed for fat, protein, Ca and P contents.

The feeding of the poor quality hay caused losses of 76, 37, 15 and 15% of the body contents of fat, protein, Ca and P, respectively, during pregnancy. Despite maintaining a moderate milk yield (1·5 kg/day) the ewes were in positive Ca and P balance during early lactation and had restored the skeleton to its initial mineral content by 42 dayspost-partum. The rate of absorption of Ca was calculated to have been at least 115 mg/ kg body weight (BW) which is double other estimates in the literature for sheep at this stage of lactation.

These differences are discussed in relation to mechanisms for adaptation of Ca metabolism which have been proposed for other species.
The effect of sudden introduction of rams on oestrus pattern of tropical ewes
Authors: Ngere L. O. , Dzakuma J. M.
Published: March 2009

Observations were made over a period of 3 years on a total of 331 Nungua Black Head and 104 West African Dwarf sheep. It was shown that ewes of these breeds responded strongly to stimulation occasioned by the sudden introduction of rams which had been separated from them for 10 months. Sudden ram presence apparently altered the normal oestrous cycle of a substantial number of ewes which unlike temperate breeds showed behavioural oestrus soon after being run with the rams resulting in about a quarter of the flock being bred on the first day of association with the ram. This behavioural oestrus must have been accompanied by ovulation as shown by the lambing records 5 months later. The observations also suggested the existence of breed differences in the degree of ewe response to sudden ram presence.
The influence of hydrogen-ion concentration on the decomposition of soil Organic matter by hydrogen peroxide (With two text-figures.)
Authors: Hosking J. S.
Published: March 2009

The decomposition of the organic matter of the soil by means of hydrogen peroxide is shown to be a function of the hydrogen-ion concentration of the soil, alkaline soils permitting of a very low degree of oxidation, while with acid soils up to 90 per cent, of the organic matter is destroyed.

The results obtained with a range of soils suggest that a portion of the organic matter is oxidised irrespective of the soil reaction, while the oxidation of the remainder is a definite function of the hydrogen-ion concentration, the relation being expressed by the equation

The proportion of the organic matter oxidised further appears to be a definite function of the clay content of the soil. Alkaline soils containing free manganese dioxide also show small losses.
The measurement of electrical conductivity of aqueous soil suspension and its use in soil fertility studies(With Five Text-figure.)
Authors: Sen Ashutosh
Published: March 2009

Several factors affecting the electrical conductivity of soil suspensions have been studied leading to the development of a simple and rapid technique for its measurement, and suitable for both moist and air-dry soils.

The possible use of the method in soil fertility studies necessitated examination of the effects of cultivations, manures, crop, meteorological variations, etc., on the conductivity measurements. This involved periodical determinations of initial conductivity (i.e. the specific conductivity of a 1 to 5 aqueous soil suspension determined at 25° C.) and the 7 days’ increase (i.e. the rise in specific conductivity of the same aqueous suspension after standing for 7 days in a thermostat at 25° C.). Soil samples were examined from several Rothamsted classical and nonclassical plots (over twenty plots were investigated for 15–20 months), and samples from experiments were also utilised during two growing seasons.
Effect of potassium fertilizer on cation uptake and concentration in oat shoots
Authors: Ragab S. M.
Published: March 2009

Pot experiments were carried out using a system in which root mats were in contact with a Danish soil for 24, 72 or 168 h. Different rates of K fertilizer (0–80 mg K/100 g soil) resulted in marked responses at 168 h of roots–soil contact, however moderately or little responses at 72 or 24 h had occurred. Marked reciprocal K–Ca, K–Mg, K–Na relationships with yield response to rates of applied K were attributed to both dilution and antagonism. The latter was not apparently brought about by competition for the carrier binding site but from the unspecific replacement competition which occurred in the interior of plant cells and not in the outer surface of the cell root membrane.
Dispersion of surface-applied salts in porous media
Authors: Pandey R. N.
Published: March 2009

Equations to predict the leached fractions of initially surface-applied salts either with irrigation water or broadcast on the soil surface have been derived from the solution of the dispersion-convection equation. Predictions obtained from these equations compare well with observed leaching data of chlorides and nitrates. It is shown that the loss of fertilizers when applied with irrigation water is reduced compared with that of applying it by broadcasting. The use of equations for predicting soil salinization and leaching of surface-concentrated salts is also indicated.