bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Developments in the design of field experiments. II. Unbalanced split-plot confounding
Authors: Finney D. J
Published: March 2009

The device of split-plot confounding for introducing additional factors into a field experiment can only give a balanced design when the number of whole plots per block and the number of replications of each whole-plot treatment are multiples of the number of sub-sets into which the combinations of the additional factors are divided. When this condition is not satisfied it may still be possible to arrange that the design shall be partially or nearly balanced in such a way as to be useful in practice and to require a reasonably simple statistical analysis. Nevertheless, the experimenter should always bear in mind the desirability of balance, and should have recourse to unbalanced designs only when the exigencies of space or material, or an unforeseen necessity of introducing extra factors during the course of an experiment, leave him with no alternative. No attempt has been made to give a comprehensive account of designs of this kind, but the numerical analysis of the yields from a typical experiment has been discussed in detail. Though the lack of balance leads to some non-orthogonality of treatment contrasts, the more important comparisons can usually be satisfactorily estimated. The details of this estimation vary from one experiment to another, but the example given should make the principles clear to those who are familiar with the analysis of variance. I am indebted to Dr E. M. Crowther and to the Agricultural Research Council for permission to use the numerical results discussed in this paper
An assessment of the variation in milk yield of ewes determined by the lamb-suckling technique
Authors: Robinson J. J. , Foster W. H. , Forbes T. J.
Published: March 2009

Ewo milk yield data obtained by the lamb suckling technique from nutritional experiments were analysed statistically to obtain estimates of the several components of variation. Diurnal variation was studied. The fitting of a sinusoidal curve removed a significant amount of variation.

There was a highly significant correlation between successive milk yields obtained at 4 h intervals. Number of lambs suckled and body weight of ewe at parturition had a significant effect on total daily milk yield.

The variation within ewes after the removal of diurnal variation and between ewes after the removal of the effects of number of lambs suckled and body weight at parturition were computed. These sources of variation were combined in a general equation which enabled the prediction of the standard errors associated with daily milk production for a given sampling technique. The practical application of the predicted standard errors is discussed.
The influence of feeding on the composition of milk. Mangels versus dried sugar beet pulp
Authors: Cranfield Harold T.
Published: March 2009

Experiments were carried out at two centres in Leicestershire during the spring of 1928, with the object of comparing the values of mangels and dried sugar beet pulp in the winter ration of dairy cows.

Two groups of cows were selected at each centre, and the usual method of feeding for a period on one ration and then reversing, was adopted. Composite samples of the milk from each group of cows were taken at six consecutive milkings per week, during the period of the experiment. Determinations of fat and solids not fat were made, and the yield of milk at each milking recorded.

Although there are indications that the change of ration caused a slight temporary variation in the quality of the milk, the secretion of milk solids followed, in a general way, the variation in yield: This is confirmed by the average composition figures representing the whole of the milk from each particular ration.

Thanks are due to Mr Thos. Hacking for placing every facility for obtaining these data at the disposal of the author.
A note on the sampling of sugar beet
Authors: Johnson S. T.
Published: March 2009

Inconsistency in the returns of sugar percentages from the factories has often perplexed growers and has at times given rise to some mistrust of the analytical procedure. Consignments of beet lifted on the same day and from the same field have been credited by the factory with widely different sugar contents. This has occurred within the writer's experience, even though the precaution was taken of loading the cart loads of beet into two trucks alternately, thereby eliminating any possibility of one truck being filled with beet from a better part of the field than the other.
Normal day to day variability of yield of milk and fat of individual cows
Authors: Bartlett Stephen
Published: March 2009

1. The day to day variability in the yield of milk and fat of cows is affected by many factors, two of which are stage of lactation and season of the year. Variability is high during the first month of lactation (particularly during the first few days after the calf is weaned), but after this a fairly constant variability may be expected. Under the conditions of management in the herd under discussion and probably in most herds in Southern England variability is highest during the month of May and also tends to be higher during the summer than the winter months.

2. A method is presented of calculating the variability in the yield of mixed milk from a herd of cows and the error to be expected when milk records and fat percentages of individual cows are calculated from a few samples.

3. When cows are milked twice daily at unequal intervals the yield of milk obtained in 24 hours is slightly less variable if a morning milk yield is added to the subsequent evening yield, than if an evening yield is added to the subsequent morning yield.
Some effects of live weight and body condition on the milk production of Blackface ewes
Authors: Peart J. N.
Published: March 2009

Approximately 15 weeks before parturition, forty-eight pregnant Blackface ewes were divided into three similar groups. During the 15–6 weeks prepartum period the ewes were fed to increase the live weights and body condition scores of ewes in each of groups A and B and to decrease those of ewes in group C. At 6 weeks prepartum mean differences of approximately 11 kg live weight and two grades of body condition had been created. Food was rationed to the ewes in all groups per kg live weight based on their weights 6 weeks prepartum, to provide the theoretical requirements of Blackface ewes bearing twin lambs. All groups of ewes made similar live-weight gains in late pregnancy and the mean birth weights of the lambs were also similar. Blood plasma F.F.A. values confirmed that the ewes were similarly nourished in late pregnancy regardless of live weight or body condition. During lactation the ewes were fed 9·2 g D.O.M./kg based on their immediate post-partum live weights, plus an allowance for a predicted level of milk production. Ewes in groups A and C were fed 0·5 and ewes in group B, 0·25 g D.O.M. per g of predicted milk production. The ration was increased after the 1st and 2nd weeks of lactation, then maintained at a constant level for the remainder of lactation. Milk production of the ewes was measured using a lamb suckling technique during a 10-week lactation. The mean daily milk production of ewes in groups A and C were similar and the yield of each of these groups was substantially greater than that of group B ewes. The mean total milk production of ewes suckling twin lambs in groups A, B and C was 127, 108 and 142 kg respectively, and of ewes suckling single lambs 104, 81 and 91 kg respectively. The mean live-weight changes of ewes in groups A and C were similar during lactation. Except for group A ewes suckling single lambs, which maintained their mean live weight, all ewes lost weight in early lactation and consistent gains were not made until late lactation. Greatest live-weight loss occurred in group B ewes and extended further into lactation. Changes in body condition followed a similar course to live weight changes. The mean daily live-weight gain of twin lambs in groups A, B and C was 279, 275 and 284 g respectively, and of single lambs, 318, 300 and 319 g respectively. The evidence indicates that ewes in lean body condition have a higher efficiency of food conversion to milk and that in situations of continuous undernourishment a high state of body condition is undesirable during lactation.
Growth cabinet studies into cold-tolerance of Festuca arundinacea populations: II. Responses to pretreatment conditioning and to number and duration of low temperature periods
Authors: Thomas W. D. , Lazenby Alec
Published: March 2009

Following three differing pre-stress temperature treatments, potted plants of three populations of Festuca arundinacea, syn. 1 and syn. 2 (North African) and S. 170 (British) were subjected to a cold stress of 20 h at – 8 °C in a growth cabinet.

In all populations, survival was greatest when the cold stress followed continuous low temperatures for 2 weeks, was intermediate after part-day low temperatures for the same period, and poorest after continuous warmth. The hardening response, especially after the fluctuating regime, was greater in S. 170 than in either syn. 1 or syn. 2, between which little difference was detectable.

There was no overall difference in survival between spring-sown and autumn-sown material, nor any apparent relationship between survival and relative growth rate.

In a further trial, the same three populations were subjected to differing periods of cold stress at — 9 °C-single exposure for 12 or 18 h periods, or one, two or three 6 h periods.

The synthetics were progressively weakened by repeated stresses, and were almost completely killed out by 12 or 18 h exposure. Differences in mortality following short and longer periods of exposure were associated with differences in soil temperatures.
Rapid semi-micro volumetric estimation of potash in leaf ash
Authors: Chapman G. W.
Published: March 2009

1. A method of moderate accuracy suitable for the routine determination of potash on a large scale is described.

2. Certain minor alterations in the method of precipitation by Lewis & Marmoy are suggested.

3. Di-sodium monohydrogen phosphate is suggested as a solvent for the cobaltinitrite precipitate before the permanganate titration, thereby simplifying previous volumetric procedures.

The writer wishes to express his indebtedness to the Director of Malacca Rubber Plantations for permission to publish this work. Acknowledgement is also made of the routine work so loyally carried out by his Asiatic staff in the development of the method, especially Messrs Warrior and Thamboo, who were chiefly responsible.
Birth weights of reciprocally cross-bred calves
Authors: Donald H. P. , Russell W. S. , Taylor C. S.
Published: March 2009

This study is based on 1015 live single calves brod by artificial insemination in a herd of Ayrshire, Friesian, Jersey and two-breed and three-breed cross cattle derived from them. Birth weights, subjected to a least squares analysis, show little effect of year or season of calving. Males were 6·0 lb. heavier than females; second and later parity calves were 6·6 lb. heavier than first parity calves.

Over the range of breeds and crosses studied, heredity was the principal determinant of mean birth weight. No evidence of heterosis was found— means for crossbred calves, however, differed in reciprocal crosses. They deviated from the mean of the parents in the direction of the maternal weight at birth. If 0 is the mean birth weight of the dam's breed or cross and 0 of the sire's breed, the mean weight of offspring is closely estimated by

This expression may not apply to the crossing of breeds differing much more in weight than the Jersey and Friesian breeds. In such crosses it is likely that small dams depress foetal growth more than large dams promote it. The maternal influence on birth weight in cattle as expressed above is in both qualitative and quantitative agreement with the maternal influence as derived from egg transfer studies in sheep.

It is a pleasure to record the authors' heavy obligations to many friends for help during the course of this long experiment. The Milk Marketing Board, in the persons of Dr J. Edwards, C.B.E., Mr T. O'Sullivan, and their colleagues at the A.I. centres made the breeding programme possible. Much time has been saved and much statistical computation cut short by the help afforded us at the Rothamsted Statistical Department by Dr F. Yates and his staff, particularly Mr J. H. A. Dunwoody. Responsibility for the animals on the farms fell at first upon Mr W. S. Biggar, and from 1950 upon Mr J. S. Tavernor. They were aided by many of whom mention must be made of Mr H. L. Williams, Mr R. Pringle and Mr R. Simpson. In the preparation of this paper the authors have been much influenced by the work and criticism of their colleagues.
The effect of histamine combined with formic or acetic acid on food intake and rumen motility, when infused into the omasum of a ram
Authors: Neumark H. , Tadmor A.
Published: March 2009

After establishing a permanent omasal fistula in a ram, solutions containing histamine with or without formic or acetic acid were introduced directly into the omasum. It was found that histamine, together with formic or acetic acid, stopped feeding and rumen motility, but formic acid and histamine, infused separately, had no effect on food intake.
Yields of, and N uptakes by, some grass species and varieties under different glasshouse conditions
Authors: Mitchell J. D. D.
Published: March 2009

The amount of dry matter produced and N taken up by seven grass species and varieties grown in a glasshouse were compared with perennial ryegrass (S. 23) and Italian ryegrass (S. 22) at different day-lengths and light intensities.

The ryegrasses Westerwolds, Italian (S. 22) and Perennial (S. 321) yielded more than S. 23. At the smallest light intensities, Westerwolds, Italian (S. 22) and Perennial (S. 24) (S. 321) ryegrasses and Meadow fescue (S. 215) took up more N than S. 23. Westerwolds and Perennial (S. 24) (S. 321) ryegrasses should be useful alternatives to the S. 23 or S. 22 strains as test crops in nutrient experiments in the glasshouse, especially when grown in the dim light during winter.
Seasonal changes in the composition of winter wheat plants, in relation to frost resistance
Authors: Newton R. , Brown W. R.
Published: March 2009

1. The adaptation of plants to resist frost appears to depend on seasonal changes which give the protoplasm stability. A study has been made of the changes occurring in winter wheat plants, of varieties differing widely in winter hardiness, during the fall and winter months.

2. By analysing the press-juice as well as the entire tissues at progressive dates, it has been possible to study the distribution of the more important constituents between the physiologically active cell fluids and the relatively inert supporting framework.

3. One of the most important changes in the quantitative relations of the various plant constituents is the reduction in moisture content. This takes place to a greater degree in hardy varieties. The resulting concentration of colloids and sugars in the cell fluids increases the resistance to freezing.
Studies in calcium-caseinogen equilibria, and their bearing on the secretion of calcium in milk. (preliminary paper.)
Authors: Wright Norman Charles
Published: March 2009

Two fundamental explanations have been advanced to account for the unequal distribution of electrolytes on either side of a cell membrane: the one bases the unequal distribution on the existence of a cell membrane of so-called selective permeability, by which the membrane is endowed with the property of presenting varying resistance to the passage of different ions; the other regards the unequal distribution as being due to the selective action of the cell constituents themselves. This latter theory regards the cell primarily as a system in which the distribution of electrolytes is governed by the equilibrium existing on either side of a membrane permeable to electrolytes but impermeable to other ionised constituents of the cell.
The proteins of green forage plants: IV. The proteins of some plants of the natural order Umbelliferae
Authors: Davies W. L.
Published: March 2009

The plants worked on in this Natural Order were the Carrot (Daucus carota L.) and the Parsnip (Peucedanum sativum Benth.). Both these plants store up reserve food in their thickened root and hypoeotyl, the disposition of the tissues being similar in both “roots.” For the extractions of their proteins, members of “races ” of these plants containing the minimum amount of core and fleshiest annuli of bast were taken, healthy, uniformly well-grown specimens being selected.
The composition of milk Part I. Variation in the solids not fat, fat and protein content of cow’s milk, and their relationship
Authors: Cranfield H. T. , Griffiths D. G. , Ling E. R.
Published: March 2009

1. Percentages of fat, solids not fat and protein were determined in over 700 samples of mixed milk from 15 herds during 1925–26. In the case of fat content, nine herds produced one or more samples below 3 per cent., one herd recording 25 per cent, of samples below this limit. With regard to solids not fat, twelve herds produced milk containing less than 8·5 per cent, on one or more occasions, the highest percentage of deficient samples recorded being 40.

2. Frequency distributions of fat, solids not fat and protein percentages in the samples analysed, are given, together with standard deviations, and mean percentages with probable errors for these three constituents.

3. Correlation tables of fat with solids not fat, and protein with solids not fat have been prepared, and graphs illustrating the variations are given.
“Single Value” Soil Properties: A Study of the Significance of Certain Soil Constants: VIII. Relationships Between the Sticky Point and the Nature of the Exchangeable Ions in the Soil.
Authors: Coutts J. R. H.
Published: March 2009

The variations in sticky point of homionic soils as determined by kneading with electrolytic solutions have been examined. In the case of sodium soils, a well-marked maximum has been found in the sticky-point/electrolytic concentration curve; and the form of the curve shows parallelism with the extent of flocculation produced by varying electrolytic concentrations.
The change in thepH of the semen of the bull after incubation
Authors: Anderson James
Published: March 2009

The mean change in thepH of 134 undiluted ejaculates of clinically normal bulls was –0·302 ± 0·027 after 1 hr. storage at 37°C. The greater thepH. change, the lower was the initialpH and the higher was the initial motility and the number of spermatozoa per c.mm. The greater the decrease inpH the poorer was the motility after incubation. The motility was better maintained in semen diluted with egg-phosphate medium, compared with undiluted semen, which agreed with the smallerpH change in this medium. There was no evidence of a relationship between thepH change and the motility after incubation and the period of time for which a high motility was maintained during storage. It is suggested that the determination of the initialpH and thepH change after 1 hr. incubation may provide a useful and accurate evaluation of the semen of the bull.
Development of mould on the cut surfaces of potato tubers
Authors: Weston W. A. R. Dillon , Taylor R. Eric
Published: March 2009

1. Cut potato tissue possesses strong inherent powers of healing which are impaired by treatment with salts of copper, cobalt, nickel and iron. Treatment is followed by mould growth, particularly by Penicillium spp., this being most profuse with copper salts and least with those of iron.

2. Association between mould growth and treatment with salts of copper, cobalt, nickel and iron suggests a periodic relationship.

3. Development of Penicillium on potato tissues following treatment with salts of copper is greater than may be explained solely on the basis of saprophytic growth following phytocidal action and. the prevention of suberization.

4. Under moist conditions, treatment of nonliving substrata such as straw, leather and skin with copper sulphate tends to prevent mould growth whilst considerable growth develops on these materials when untreated.
Digestibility trials with poultry. XI. The digestibility and metabolizable energy of raw and cooked potatoes, potato flakes, dried potato slices and dried potato shreds
Authors: Halnan E. T.
Published: March 2009

A series of digestibility trials on fowls with a number of potato products led to the following conclusions:

1. Raw potatoes, though readily consumed by fowls when mixed with other foods, are not readily utilized, the potato starch largely escaping digestion.

2. Boiled potatoes are readily utilized by the fowl, the preliminary cooking altering the structure of the starch grain in such a way as to render the starch readily digestible.

3. The energy derived from 1 lb. of cooked potatoes is, in the fowl, equivalent to the energy derived from no less than 5 lb. of raw potatoes.

4. The food value of dried potato products is shown to be dependent upon the nature of the heat treatment to which the potatoes are subjected in the preliminary treatment of drying.

5. Dried potato slices of the type produced in sugar-beet factory driers have a value approximating that of well-boiled potatoes, both values being compared on a dry-matter basis.
The composition and nutritive value of marrow stem kale and thousand head kale
Authors: Woodman H. E. , Evans R. E. , Eden A.
Published: March 2009

The paper records the results of an investigation into the composition, digestibility and nutritive value of marrow stem kale (both unthinned and singled-out) and thousand head kale. A number of the main findings are recorded below.

The average dry-matter content of unthinned marrow stem kale during September and October was 13·3 per cent. During the following January it had reached a slightly higher level, namely, 14·2 per cent. Singling out of the marrow stem kale appeared to exercise little effect on the dry-matter content of the crop. Thousand head kale, with an average dry-matter content of 15·8 per cent., is significantly richer in dry matter than the marrow stem kale, although this advantage was offset by the lower yield, in terms of green matter, given per acre by the thousand head kale.
Studies in the absorption and excretion of certain minerals by poultry. I. The excretion of calcium, phosphorus, carbonate and chloride by hens, with special reference to variations during the day, and in relation to oviposition
Authors: Tyler Cyril
Published: March 2009

1. An experiment was performed to obtain information on the fluctuations in excretion of calcium, carbonate, phosphorus and chloride within the day.

2. It was found that there was a lower excretion of calcium and carbonate in the 12 midnight–8 a.m. subperiod than in the 8 a.m.–4 p.m. and 4 p.m.–12 midnight subperiods. Phosphorus showed a much smaller variation, whilst chloride gave inconsistent results.

3. When eggs were laid there was a distinct increase in phosphorus and chloride excretion and a fall in calcium and carbonate excretion. These changes, although related in time to each other, were not clearly related to the time of oviposition. Thin-shelled eggs did not give the same results, much smaller changes being observed.

4. When changes were made in the amount of calcium carbonate added to the basal ration the effect on the composition of the excreta was noted within 4 hr., the full effect showing itself within 16 hr.

5. The significance of these results in relation to egg-shell formation is discussed.
Effects of season and breed on sow performance in the seasonal-equatorial climate of Southern Nigeria
Authors: Steinbach J.
Published: March 2009

Preweaning litter traits of 289 Large White (LW) and of 167 Landrace (LR) litters born between 1 January, 1967 and 31 December, 1969 were analysed for seasonal effects. The month during which farrowing occurred exerted highly significant effects on the average piglet weight at birth and at weaning, as well as on the preweaning piglet weight gain (P <0·001). Piglet weight at birth was higher during the hot and dry months of the year, while the preweaning piglet weight gain was greater during the cooler season. The heaviest piglets at weaning were those born in August, the coldest month of the year. Piglet weight at birth was negatively correlated with the mean relative humidity of the month of farrowing (r = -0·79; P <0·01). The percentage of stillborn piglets was high in litters born during March and April (P < 0·005), and the positive correlation between the mean physiologically effective temperature and the percentage of stillborn piglets (r = +0·57) approached significance (P < 0·10).

The considerable variations in litter size and litter weight at birth and at weaning as well as the variations in preweaning mortality were not significant.

The two breeds differed significantly (P < 0·005) in piglet weight at birth (LW: 2·8 lb; LR: 3·0 lb), in litter weight at birth (LW: 24 lb; LR: 28 lb), and in the percentage of stillborn piglets (LW: 4·5%; LR: 7·5%).
The effects of the date of applying anhydrous ammonia or a solid nitrogen fertilizer on the spring growth from a pure perennial ryegrass sward
Authors: Reid D. , Catle M. E.
Published: March 2009

Two 1-year experiments are described in which a single dressing of 120 lb N/acre (134 kg/ha) was applied to a grass sward as anhydrous ammonia (82% N), ammonium nitrate (34·5% N) or sulphate of ammonia (21% N) at various dates from December to April. The pattern of primary growth from each of the treatments was recorded from early April until mid-June by frequent sampling of the herbage to determine the dry matter and crude protein yields. At every date of fertilizer application from late January to mid-April the growth rate of the herbage was markedly lower with anhydrous ammonia than with ammonium nitrate. With the December applications the spring growth rate of herbage from the anhydrous ammonia treatment was similar to that from the ammonium nitrate treatment. Applications of sulphate of ammonia gave results almost identical with those obtained from ammonium nitrate. The calculation of the dates on which a yield of 2000 lb dry matter/acre (2242 kg/ha) would have been available for dairy cow grazing showed clearly a delay of 12–15 days where anhydrous ammonia rather than ammonium nitrate was applied. The response to anhydrous ammonia was improved by applying it early in the year but solid nitrogen fertilizers, applied either early in the season or when growth was starting, gave higher yields of herbage than anhydrous ammonia.
Effects of some soil conditions on sugar-beet seedling emergence
Authors: Longden P. C.
Published: March 2009

Seven soil conditioners added to a sandy clay soil at Saxmundham did not benefit sugar-beet seedling emergence in four experiments in 3 years. In microplots at Broom's Barn free draining peat and sandy loam gave consistently more seedlings than limestone loam or flinty loam. In the laboratory, for each of three soil types, emergence was maximal only for a small soil moisture range and decreased rapidly when soils became drier or wetter. This suggests that conditioners which increase water-holding capacity should be tested on sandy loams rather than clay soils and that seed-bed preparation on heavier soils should seek to aerate the soil.
The association between kemp and some vigour and wool characteristics in Barki and Merino Barki cross
Authors: Guirgis R. A. , Galal E. Salah E.
Published: March 2009

Data were collected from 549 Barki and Merino cross sheep during 1967, 1968 and 1969 to study the relation between kemp production and body vigour. The study also included the staple length and greasy fleece weight. The results showed that:

Age had a marked effect on the traits studied. Whereas kemp frequency (score) declined slightly as age proceeded, showing a significant reduction in the seventh shearing season, the staple length and fleece weight decreased after the second shearing season.

Differences due to sex, year and breed occurred, though the pattern differed in the different traits.

Kemp showed a highly significant correlation with birth and weaning weights, as indicating the animal vigour, and was negatively correlated with fleece weight.

Staple length was negatively correlated with birth and weaning weights and positively correlated with fleece weight.

Fleece weight was positively correlated to birth and weaning weights and negatively correlated to kemp score.

Kemp score in the Barki sheep was shown to be quite repeatablo (repeatability = 0·5).
Foraging of bees on oil-seed rape (Brassica napus L.) in relation to the stage of flowering of the crop and pest control
Authors: Free J. B. , Ferguson A. W.
Published: March 2009

Large populations of bees often continue to forage on oil-seed rape crops until flowering ceases. Applications of insecticide to crops in the late flowering stage could be hazardous to these bees.
Soil temperature and its association with maize yield variations in the Highlands of Kenya
Authors: Cooper P. J. M. , Law R.
Published: March 2009

summary

In the Highlands of Kenya every 1-week delay in planting maize after the onset of the rains reduces the grain yield by approximately 0·6 t/ha. No satisfactory explanation has been found for this phenomenon. A physiological growth study was made on four dates of planting per year over 4 years. Early growth rates and maximum crop growth rates showed a progressive decline with delay in planting which resulted in smaller plants at 5 weeks post-emergence and at 50 % tassel emergence in maize planted later. There was a strong relationship between the size of plant at tasselling and the final grain yield and a highly significant relationship (r = 0·94) between the size of plant at 5 weeks post emergence and the final grain yield. Other environmental studies showed that soil temperature at 7·5 cm, coupled with a soil moisture stress factor, largely controlled the dry-matter production rate during early growth, and consideration of the mean value of these two variables over the first 5 weeks of growth accounted for 70% of the variation of dry matter at 5 weeks post-emergence. It was further shown that 82% of the variation in final grain yield caused by date of planting could be accounted for by consideration of the mean value of these two variables during the first 5 weeks of growth.
Motility and survival of spermatozoa in mixed semen from different bulls
Authors: Dott H. M. , Walton A.
Published: March 2009

Semen samples of five Dexter bulls were mixed and the effects of mixture on the live/dead ratio, the percentage of abnormal cells and on motility and survival of motility as measured by impedance change frequency were studied. Altogether fifty-six samples and mixtures were examined. No effect of mixture on live/dead ratio nor on percentage abnormals was found, but mixtures of semen had a motility which was slightly nearer the value of the less active component of the mixture than that of the means of both components. No explanation for this effect is offered.
Field experiments on concentrated organic nitrogen fertilizers
Authors: Warren R. G. , Cooke E. H. , Cooke G. W.
Published: March 2009

Hoof, formalized hoof, formalized casein, leather wastes and dried blood were compared with ammonium sulphate for vegetables in several field experiments which were continued for a number of years. Residual effects were measured in one experiment at Rothamsted.

For crops which had a high requirement for nitrogen, hoof and formalized casein tended to give somewhat lower yields than equivalent ammonium sulphate. Organic nitrogen fertilizers tended to be slightly superior to ammonium sulphate for less responsive crops, and also in experiments where the high rate of ammonium gave lower yields than the medium rate.

Crushed hoof and a formalized casein product gave similar yields of most crops. There were no marked gains from treating hoof with formalin; a coarse (5·7 mm.) sample of formalized casein did not give materially different yields from the ordinary fine (2 mm.) product.

One leather product made by simple roasting was inferior to ammonium sulphate and to hoof. Other leather wastes processed by alkalis did not behave very differently from crushed hoof or from ammonium sulphate. Dried blood was tested in a few experiments, there were no significant differences between yields given by blood and by ammonium sulphate.

In experiments on a light soil, spring cabbages planted in autumn were very sensitive to the time of applying nitrogen fertilizer; there were much larger gains in yield from ammonium sulphate applied half at planting and half in spring, than from either ammonium sulphate or organic nitrogen fertilizers applied wholly at planting.
Observations on the corpora albicantia in the ovaries of normal and infertile dairy cows
Authors: Dawson F. L. M.
Published: March 2009

The ovaries from 251 cattle with known histories were dissected, and this work was linked with clinical and histopathological studies. In almost 20% of the cattle, resorption of corpora albicantia appeared to have taken place, beginning usually, after the fourth pregnancy. In 10% of cattle more corpora albicantia were found than corresponded with the normal pregnancies. Most such cases appeared to be associated with unrecognized ‘temporary pregnancies’, but normal pregnancy associated with two corpora lutea, as in the camel, may occur, though rarely. A scheme with correction factors, for allocating random samples to age categories, has been prepared. In 110 cattle, or 44%, miniature as well as full-sized corpora albicantia were recovered. Evidence from their histories is brought forward that the miniature corpora correspond to ‘temporary pregnancies’ of perhaps 2–5 months duration. This is cross-checked and confirmed, both from the histories of 112 cows yielding no miniature corpora, and also by correlation with the histopathological findings from the genitalia.
The feeding of cod-liver oil to growing-fattening pigs
Authors: Worden Alastair N.
Published: March 2009

1. Fresh, good quality cod-liver oil, containing an antioxidant, was incorporated at varying levels of up to 5% in the rations of pigs throughout the whole period from weaning (at 56 days) to bacon weight (at 196 days), without any evidence of detrimental effect.

2. Cod-liver oil did not at any level produce discoloration of the body fat, fishiness or other taint, or any other adverse effect upon carcass quality as judged subjectively and by routine measurements. Increasing levels of cod-liver oil increased the iodine number of the body fat, but this was not accompanied by any visual softening.

3. Although the experiment was not designed to assess the effect of high levels of cod-liver oil upon productive efficiency, it was, nevertheless, found that improvement in food conversion accompanied increases in the amount of cod-liver oil fed.
The comparative precision of estimates of body composition in living pigs, obtained from numerous different predictors applied severally or jointly
Authors: Houseman R. A. , McDonald I.
Published: March 2009

The body composition of 24 pigs reared at different rates of growth from 25 kg live weight was estimated when they each weighed about 90 kg live weight. Feed conversion corrected for the energy requirements of maintenance (CFCR), external and ultrasonic measurements, and measurements of Evans Blue, deuterium oxide and potassium-42 were applied simultaneously to each pig, and were used to predict the weights of the fat-free mass, lipid, and dissectible fat and lean.

The best individual predictors of body composition were CFCR, deuterium oxide and potassium-42, but Evans Blue, external and ultrasonic measurements were not as closely associated with the four body components.

In combination, it was generally found that two predictors could predict the weight of a body component more closely than either predictor in isolation.
Influence of diet on plasma thyroxine response to thyroid stimulating hormone in growing lambs
Authors: Godden Patricia M. M. , Weekes T. E. C.
Published: March 2009

In an initial experiment four mature sheep were injected with saline or 25, 75 or 150 m units bovine thyroid stimulating hormone (TSH)/kg live weight. All doses of TSH stimulated a similar release of thyroxine.

In a second experiment ten lambs were fed chopped dried grass from weaning until 108 days old (period 1). Five of the lambs (group 1) were then fed 30% barley: 70% grass until 178 days of age; the remaining lambs (group 2) continued to receive grass (period 2). After 178 days group 1 was fed 70% barley: 30% grass and group 2 30% barley: 70% grass (period 3). All lambs were injected with 25 m units TSH/kg live weight at 105–108 days of age, 174–178 days and 220–227 days. The thyroxine response to TSH was greatest in lambs fed 30% barley: 70% grass in periods 2 and 3. Plasma insulin and glucose concentrations tended to decrease after TSH.
Interactions of phosphorus, magnesium and zinc affecting the iron content of maize
Authors: Agbim N. N.
Published: March 2009

Five calcareous soils (pH 7·3–7·7) designated A-E, deficient in or responsive to Zn and containing Fe in the critical or adequate range, were used in a glasshouse study on maize to assess the effects of P alone or in combination with Mg, Zn or both on the content of Fe in maize.

Overall, P significantly depressed Fe in maize. When Mg was applied to a P or PZn treatment, it either depressed or had no effect on Mg in maize but it significantly (P < 0·001) increased Fe. For the soil where Fe in maize was increased with P treatment, the Zn concentration in the tissue was relatively very low. By contrast, in another exception where PMg treatment depressed Fe in maize, tissue Zn concentration was relatively very high. There was a significant negative correlation (r = –0·45; P < 0·05) between Zn and Fe in maize tops.
Nitrogen and potassium uptake by high-yielding potato crops
Authors: Ifenkwe O. P. , Allen E. J.
Published: March 2009

Results are presented from two experiments (1973 and 1974) in which high potato yields were obtained (60–70 t/ha). In both, Désirée and Maris Piper accumulated much more N and K (> 200 and 300 kg/ha respectively) than was applied as fertilizer (160 kg N and 189 kg K/ha). Increasing planting density (to levels above commercial practice) increased nutrient accumulation but had only small effects on yields. Thus, high yields are associated with but not necessarily caused by large accumulations of nutrients. As a general principle, increasing fertilizer rates above those shown to be optimal will not increase yields.
Evaluation of the effects of environmental temperature and nutrition on growth and development
Authors: Dauncey M. J. , Ingram D. L. , Walters D. E. , Legge K. F.
Published: March 2009

Growth and development of young mammals have been investigated in relation to environmental temperature and energy intake. The experimental design and statistical analysis have allowed an evaluation of the separate and combined effects of two environmental variables and the time it takes for these effects to develop. Piglets aged 14 days lived at either 35 or 10 °C, on a high or low energy intake (the energy content of the former was twice that of the latter). The influence of each of the four treatment combinations was assessed up to 64 days of age.

At 64 days of age the piglets at 35 °C on the high intake (35H) were twice as heavy as those at 10 °C on the low intake (10L). The other two groups (35L and 10H) had similar body weights, and these were between the 35H and 10L. Ambient temperature had a rapid influence on appearance and morphology: animals in the cold were shorter and squatter than those in the warm. In general, energy intake influenced the absolute size of the internal organs whereas temperature affected their size relative to body weight. Skeletal growth was faster in the warm than the cold, and on the high than the low intake. No statistically significant interactions were generally found between temperature and intake, indicating that their effects were exerted independently. Most of the effects were established after only 17 days.

The present investigation has helped in interpreting earlier studies on growth which concentrated on the effects of only one of the two environmental variables of temperature and nutrition. It emphasizes the key roles of nutrition in adaptation to environmental temperature, and of ambient temperature to nutritional studies.
The lactation curve in cattle: a mathematical model of the mammary gland
Authors: Neal Heather D. St. C. , Thornley J. H. M.
Published: March 2009

A simple model of the mammary gland is described. In this model secretory cells are produced by cell division from undifferentiated cells, and the rate of division is determined by the level of a postulated hormone. The total activity of the milk secreting cells depends on the number of cells, substrate supply (assumed constant), and the amount of milk currently present in the animal. The secretory cells have a finite life, although their death may be expedited by milk remaining in the animal over a longer period of time. The model gives a good description of an experimental lactation curve; it is able to simulate the removal of milk by a suckling calf and machine milking with a variable number of milking periods a day.
Experiments on the nutrition of the dairy heifer: I. Protein requirements of yearling stock
Authors: Bailey G. L. , Broster W. H.
Published: March 2009

The literature on the protein requirements of young dairy heifers has been discussed and the wide variations noted, both in quantities estimated for particular live-weight ranges and in the suggested trends of requirements with live weight.

Short-term trials have been conducted in which the effect of variation in protein intake on rate of live-weight gain of dairy heifers of various ages was studied.

The response to increments of protein in the ration was found to be curvilinear with a rapid decline in response above critical levels of intake. This level varied with the live weight of the animal, being 0·8 lb. crude protein at 300 lb. live weight and 1·0 lb. at 400 and 500 lb. when rations based on hay, decorticated ground-nut meal and flaked maize were fed.

These levels are somewhat lower than estimates of protein requirements quoted in the literature, though the trend indicated in them agrees with some of the published data.

No marked difference was observed between the values of decorticated ground-nut meal and white fish meal as protein supplements. Urea was inferior to decorticated ground-nut meal.

The overall depressant effect of straw on rate of live-weight gain is demonstrated and discussed.
The effect of seed rate and nitrogen on lodging and yield of spring barley (field experiments 1954 and 1955)
Authors: Glynne Mary D. , Slope D. B.
Published: March 2009

The extent to which spring barley crops lodged at Rothamsted increased with seed rate and with nitrogen, and was much more severe in the wet summer of 1954 than the dry one of 1955. Although in 1954 all plots were extensively lodged by harvest there were great differences in date of lodging; 50% of the area was lodged later in plots sown with 1 than with 3 bushels/acre, the delay being 8 days with 1½ cwt. sulphate of ammonia, 14days with 3 cwt. and 21 days with 4½ cwt. The weight of unit length of the basal part of the straw was reduced by higher seed rate and to a smaller extent by nitrogen.

Yield of total grain was only slightly affected by treatments; yield of dressed grain was decreased by higher seed rate in 1 year and by nitrogen in both years.
Measurement of the phosphorus content of herbage selected by grazing cattle: influence of route of isotope administration, animal live weight and dose size on specific activity of saliva
Authors: McLean R. W. , Little D. A.
Published: March 2009

In an earlier paper (Little, McLean & Winter, 1977) we reported a technique for the measurement of the phosphorus content of the diet consumed bygrazing cattle, which recently has been used successfully to measure the dietary intake of phosphorus by sheep grazing Mitchell grass (Astrebla spp.) pastures in western Queensland (Beale & McMeniman, 1978). In this technique, phosphorus of salivary origin is distinguished from that of plant origin in samples extruded by oesophageally nstulated animals by prior labelling of salivary phosphorus with the isotope 32P following the intravenous infusion of Na2H32PO4. The difference in specific activity between saliva and extruded bolus is used as the basis of the calculation of the phosphorus content of consumed herbage. Oesophageally nstulated animals may graze experimental pastures for an hour or more while samples are collected from them. It is important to have an accurate measure of saliva speoific activity, representative of that secreted during the grazing period; therefore, application of the technique is facilitated if the rate of change in saliva specific activity during collection periods is slow and linear.
Comparison of the effects of nitrogen fertilizer on the yield, nitrogen content and quality of 21 different vegetable and agricultural crops
Authors: Greenwood D. J. , Cleaver T. J. , Turner Mary K. , Hunt J. , Niendorf K. B. , Loquens S. M. H.
Published: March 2009

The effect of level of N fertilizer on the composition, yield and quality of 21 crops was studied in experiments on adjacent sites of the same field to aid in the development of fertilizer recommendations.

Yield of each of the crops first increased and then either remained the same or declined with further increases of N fertilizer. Interpretation by means of a simple model enabled response curves to be characterized by two parameters; one representing the beneficial component of the response and the other the detrimental component. Both varied greatly from crop to crop.

The magnitude of the beneficial component of the response of most non-leguminous crops was largely determined by the potential demand of the crop for nitrogen; the exceptions were some root crops which responded less than would be expected on this basis. The adverse component was serious with root crops and those crops that are in the soil for only a short period. High levels of N increased the ratio of foliage to storage root dry weights even when total dry matter was unaffected. The changes were associated with a considerable increase in the % N in the dry matter of the roots.

When crops were grown with their optimum levels of N fertilizer a simple linear. relationship between the mean %N in the dry matter and the total weight of dry matter per unit area covered all crops. Simple relationships also existed between total dry matter of non-leguminous crops and (a) the amount of N taken up by the crop from unfertilized soil, (b) the recovery of added fertilizer by the crop and (c) the beneficial component of the response of crops harvested before October.

Percentage N in the dry matter at harvest was not a sensitive indicator of the extent to which plant growth was restricted by lack of nitrogen; a difference of 0·1% N in the plant material was associated with a 10% increase in yield.

N fertilizer levels influenced the % dry matter and the incidence of crop disorders such as rotten roots and tissue discoloration, but the effects were seldom appreciable with practicable levels of fertilizer application.
Utility of Rhizobium in the phyllosphere of crop plants: two-way exchange of metabolites between Rhizobium and the host plant
Authors: Nandi A. S. , Sen S. P.
Published: March 2009

The nature of the ectosymbiotic association between Rhizobium and such legume leaves as Bengal gram and mung bean was investigated using radioactively labelled compounds. About 8% of the 14CO2 fixed photosynthetically in the 70% ethanol soluble fraction was leached out within 1 h of contact with water. The 14C-compounds leached out include sucrose, serine glycine, glutamic acid, malate, alanine and succinate. A part of the 14C-activity was incorporated by Rhizobium cells sprayed on leaves. Association with rhizobia increased the rate of photosynthesis and leaching by 129–240% and 134–281%, respectively. Bacterial metabolites are translocated along the midribs and veins to different plant parts. The beneficial effects are not restricted to members of the same cross-inoculation group.