bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complete diets for dairy cows: comparisons of feeding to appetite with rationing according to milk yield
Authors: Greenhalgh J. F. D. , Reid G. W. 
Published: March 2009

SummaryTwo experiments were made, each with 35 autumn-calving cows fed on complete diets containing 40–70% hay and 60–30% concentrates. In both experiments, cows fed to appetite on a diet containing 11 MJ metabolizable energy/kg D.M. for weeks 7–24 of lactation ate about 20% more than cows rationed according to yield, but produced only about 3% more milk. The cows fed to appetite gained more in live weight, but lost their weight advantage during the subsequent grazing season.In Expt 1, a further group of cows were fed to appetite on diets progressively reduced in metabolizable energy content from 11·0 to 9·2 MJ/kg. Dry-matter intake decreased by about 1·2 kg/day per 1 MJ reduction in energy content. The lower dry-matter and energy intakes of cows on this treatment did not significantly reduce their milk yield, but their response when turned out to grass suggested under-nutrition in late winter. In Expt 2, increasing the energy content of the diet in early lactation (weeks 7–12) and reducing it thereafter had no significant effect on milk yield.Within each treatment group there were reasonably close relationships between energy intake and energy requirement. Nevertheless, it seems likely that the efficiency of feed utilization of cows fed on complete diets will be low unless intake is controlled by energy dilution.
The deposition of sulphur in rainwater in central Kenya
Authors: Bromfield A. R. , Debenham D. F. , Hancock I. R. 
Published: March 2009

SummaryThe deposition of S in rainwater was measured at ten locations in central Kenya, monthly for 1 year (1977–8). Amounts deposited ranged from 1·58 to 3·81 (mean 2·47) kg S/ha. Concentrations ranged from 0·10 to 0·17 (mean 0·12) mg S/l rainwater. The washout factor (w) was 200 and the vertical deposition velocity (Vg) for dry deposition was 0·31 cm/sec. Two locations were affected by local anthropogenic emissions. The agricultural significance of these results is briefly discussed.
Studies on reproduction in prolific ewes
Authors: Robinson J. J. , McDonald I. , Fraser C. , Gordon J. G. 
Published: March 2009

SummaryEstimates of the energy contents of the foetuses, placentae, foetal fluids, empty uteri and maternal empty bodies at 88 and at 144 days of pregnancy were obtained from a comparative slaughter experiment on Finnish Landrace × Dorset Horn ewes. Over this period the mean daily intakes of metabolizable energy (ME) for ewes with twin, triplet or quadruplet foetuses were 11·2, 12·0 and 12·2 MJ respectively (low plane of feeding) or 14·4, 15·2 and 15·3 MJ (high plane of feeding), total numbers of ewes being 15, 23 and 7 respectively. The diet contained 8·2 MJ of ME and 153 g crude protein per kg dry matter. All six categories of ewe lost energy from maternal empty-body tissues between 88 and 144 days at mean daily rates of 2·7, 4·1 and 4·9 MJ (low plane) and 1·4, 2·7 and 3·6 MJ (high plane), according to litter size. Rates of energy deposition in the gravid uterus were 0·72, 0·93 and 1·07 MJ/day respectively, and were not affected by plane of nutrition. Estimates of heat production from these balance data were confirmed by direct measurements made on about half of the ewes.Estimates of the gross efficiency of utilization for foetal growth of the combined energy from maternal tissue and from ME intake, after allowing for maternal main–tenance, were similar for each litter size but were 0·14 and 0·11 on the low and high planes of feeding respectively. Consideration of these together with other published observations suggested that efficiency of utilization of ME in pregnancy increases linearly with the ME concentration of the diet and at concentrations below 10 MJ/kg dry matter is less than the efficiency of utilization of energy derived from maternal tissue loss.
The influence of cultural factors and mildew on yield of winter barley
Authors: Bainbridge A. , Finney M. E. , Jenkyn J. F. 
Published: March 2009

SummaryIn experiments on winter barley in 1975–6 and 1977–8 early or late sowing, full or half seed rate, nitrogen applied in March or April and tridemorph spray applied in autumn, early spring and late spring were assessed factorially in all combinations for their effects on mildew development, crop growth and grain yield.Date of sowing had the biggest effect on yield. Early-sown crops (24 September 1975, 6 October 1977) greatly out-yielded the late-sown; by 79·8% in the first year and 53·9% in the second. Late sowing (6 November 1975, 2 November 1977) approximately halved plant emergence. Although late-sown plants developed more tillers, more grains per ear and larger grain this failed to compensate for the thinner stand.Sowing at half seed rate did not decrease yield when compared with the crop sown at the full seed rate on the same date. In contemporaneous crops extra tillering and larger ears generally compensated for fewer plants.The effect of date of applying N was variable. April N gave the best yield in the early· and late-sown crops in 1975–6 and in the late-sown crop in 1977–8. However, in the early-sown crop in the second year March N was best. Number of ears was increased in early-sown crops by March N but date of N application had no influence on number of ears in late-sown crops or on the number of grains per ear in any crop.The winter of 1975–6 was mild and mildew developed on both early· and late-sown crops throughout their growth.Single tridemorph sprays applied in autumn (14 November) to the early-sown crop or winter (25 February) to the late-sown crop or early spring (9 April) to both crops gave significant yield increases of 6·3–7·6%. Applying two sprays, one in autumn or winter plus one in early spring gave an increase equal to the sum of each applied separately. A late spring spray (14 May) had no significant effect on yield. The 1977–8 winter was colder and although mildew was moderate on the early-sown crop in autumn it was almost absent from this experiment after winter. Spraying failed to increase yield significantly.
Direct drilling and ploughing: their effects on the distribution of extractable phosphorus and potassium, and of roots, in the upper horizons of two clay soils under winter wheat and spring barley
Authors: Drew M. C. , Saker L. R. 
Published: March 2009

SummaryA study was made in the unusually dry 1975–6 season of the distribution of extractable phosphorus and potassium, and of roots, in the top soil in the second year of direct drilling on a Denchworth series clay (with winter wheat), and in the fourth consecutive year of direct drilling on an Evesham series clay (with spring barley). With both soils there were greater accumulations of phosphorus and potassium in the upper 5 cm with direct drilling compared with ploughing. In the Denchworth soil there were smaller concentrations of phosphorus at all depths below 5 cm with direct drilling and in the Evesham soil this depleted zone was located between 10 and 15 cm depth. There was little extractable phosphorus at depths below 20–30 cm.Measurements of the overall change in concentration of extractable nutrients at each depth between the beginning and end of the season suggested that there may have been contrasting patterns of depletion with cultivation treatments. Depletion was greater between 2·5 and 5·0 cm with direct drilling, and for spring barley on Evesham soil this coincided with the zone in which roots were most abundant. For potassium, there was an increase in the concentration in the 0–2·5 cm zone, apparently due to potassium loss from the maturing crops. At harvest, the total depletion of phosphorus from all zones between 0 and 50 cm depth was appreciably less than data (Cannell & Graham, 1979) on the content of phosphorus in the crop per unit land area, indicating that release from non-extractable reserves in the soil had occurred.Despite the exceptionally dry summer of 1976, crop growth and yield were not adversely affected by the tendency for extractable phosphorus and potassium, as well as roots, to concentrate in the upper layers where desiccation could occur most readily. Possible reasons for this, as well as factors that may contribute to the observed patterns of distribution of nutrients and roots, are discussed.
Further studies on the effects of plant density, spatial arrangement and time of harvest on yield and root size in carrots
Authors: Salter P. J. , Currah I. B. , Fellows Jane R. 
Published: March 2009

SummaryThree experiments were carried out over a 2-year period to study the effect of plant density and spatial arrangement and the time of lifting on yield and root size of carrots. Plant density treatments ranged from 108 to 1553 plants/m2 and plant arrangement was varied by growing the plants in 1-, 2-, 3-, 4-, 5-, 10-, 18- and 36-row systems within a 152 cm bed; there were either two or three harvests in each experiment.Total plant fresh weight, total root yield and mean root weight were not significantly affected by plant arrangement over the range studied, but they all progressively increased with later harvests. The asymptotic relationships between these yield variables and plant density were adequately described by the equation of Shinozaki & Kira (1956), the relationships being significantly different for each harvest.Yields of canning-size roots (20–30 mm diameter) were influenced by time of harvest, plant density and the interactions between these two variables. The yield of canning-size roots increased with plant density to a maximum and then declined, the maximum yield being achieved at a higher density with later harvests. In two out of the three experiments there was no effect of spatial arrangement on canning root yields but in the third experiment there was a significant row system × density × harvest interaction.The numbers of roots harvested per metre of row did not differ significantly between the ‘outer’ and ‘other’ rows for any row system treatment. The mean root weight, however, was consistently greater from the outer rows of systems with three or more rows and this ‘edge’ effect became larger with later harvests.The results are discussed in relation to other published data and to carrot production. It is concluded that any of the tested row systems are equally satisfactory for carrot production and the choice can be based on such considerations as the availability of suitable harvesting equipment.
A contribution to the study of the problem of low fertility among Merino ewes in South Africa
Authors: Hunter G. L. 
Published: March 2009

During the 12 months from September 1955 to August 1956, the reproductive tracts and ovaries of 4094 adult Merino ewes, recovered from the municipal abattoir at Pietermaritzburg, were examined. The great majority of the ewes had been consigned to the abattoir from one of three regions, between which differences in the nutritional value of the natural vegetation at different times of the year are recognized. From observations of the occurrence in the ovaries of active corpora lutea, it appeared that in some areas, mating Merino ewes during autumn and early winter is likely to result in the greatest percentage of ewes conceiving and in the highest lambing percentages. There was a suggestion, however, that in the more arid karoo areas, the percentage of ewes ovulating, as well as the mean ovulation rate per ewe, may remain relatively constant throughout the year. It seems likely that the low fertility of ewes of this breed may be due partly to the practice of introducing the rams into the flock at a time of year (spring and summer) in which many of the ewes are anoestrous, a practice which is often adopted in South Africa in order to avoid the poor growth rates which are known to occur among young lambs as a result of the high temperatures and the internal parasite infestations that are comcommon in the summer months. A need, in different areas, for extensive experimental evidence of the most suitable season for mating, is indicated.No evidence of nutritional effects on fertility, either within or between areas, was obtained, but it is suggested that a higher proportion of ewes in certain areas may be capable of lambing in autumn as a result of more effective selection for this trait in these areas. There is also evidence that lack of fertilization of ova and early embryonic death may contribute significantly to the breed's low fertility.Corpora lutea were observed more frequently in the right ovary than in the left. In gravid uteri, a greater proportion of foetuses were found in the right horn and, in addition, significantly more ova apparently migrated from the left ovary to the right horn than from the right ovary to the left horn. The numbers are given of large (diameter > 4 mm.) and medium (diameter 2–4 mm.) follicles observed in the ovaries both of non-pregnant ewes and of ewes in different stages of pregnancy, these stages having been estimated from measurements of foetal crownrump lengths.
Visual judgements of quality in meat I. Assessments of the proportion of lean to fat in bacon from photographs of the cut side
Authors: Gatherum D. P. , Harrington G. , Pomeroy R. W. 
Published: March 2009

1. Eight experienced judges used a 20-point scoring scale in different ways when assessing the ‘proportion of lean to fat’ from the same photographs of cut bacon sides presented in the same arrangements. The average score for the 220 judgements made during the experiment by a single judge, which represents his over-all level of scoring or ‘standard of judging’, ranged from 13·7 to 12·0. The standard deviation, a measure of the degree of discrimination attempted by the judge, ranged from 3·26 to 4·74.2. The judges varied in their consistency of assessment or ‘repeatability’. The standard error for a single judge, measuring the extent of the variation of his scores within photographs, ranged from 0·89 to 1·99. The judges who attempted to discriminate most between photographs tended to be the least consistent in their judgements, although one judge was a notable exception to this trend.3. The consistency of judgement tended to decrease from the good (high-scoring) rashers to the poor (low-scoring) rashers, but this effect was more marked for some judges than for others.4. Some of the variation in the scores awarded to each photograph was due to alterations in the standard of judging from batch to batch. When this was allowed for, the standard errors were all reduced and ranged from 0·61 to 1·31. The judges tended to adjust their standards according to the average quality of the batch being assessed. This led to the variation among the average scores for the batches being less than it would have been had their standards remained constant.5. Alterations in the standard of judging during the experiment affected the scores awarded to good (high-scoring) rashers rather less than those awarded to poor (low-scoring) ones.6. The correlations between the individual judge's mean scores for the forty-four photographs and the over-all mean scores were very high. For seven judges, they ranged from 0·962 to 0·984, whereas for the eighth judge the correlation was 0·918. The lower correlation for this judge was due to two rashers with very thin fat being heavily marked down.7. The correlations between the over-all mean scores and two different combinations of three objective measurements were both about 0·92; these measurements were therefore slightly less closely related to the over-all scores than were an individual judge's mean scores.8. The possibility of making the experimental technique more realistic and of improving the precision of such visual judgements by providing photographic scales of reference are discussed.
Some effects of bran and cellulose on the water relationships in the digesta and faeces of pigs Part II. The effects of adding different levels of fibrous cellulose to a highly digestible purified ration
Authors: Cooper P. H. , Tyler C. 
Published: March 2009

1. Two experiments have been described in which pigs were fed different levels of fibrous cellulose superimposed on a highly digestible purified basal ration. These experiments involved 24 hr. faecal collections and ultimate slaughter of the animals, together with analysis of faecal material and gut contents.2. The results of these experiments, together with those from experiments described in the previous paper in this series, have provided the basis for a discussion of the effects of adding bran and cellulose to pig rations, and of the influence of the progress of the residues of feeds through the digestive tract, on the pattern of excretion and the dry matter content of the faeces.
Some effects of bran and cellulose on the water relationships in the digesta and faeces of pigs Part III. The effect of level of water intake and level of cellulose in the ration on the dry-matter content of the faeces
Authors: Cooper P. H. , Tyler C. 
Published: March 2009

1. An experiment has been described in which pigs were fed rations containing four different levels of cellulose, each ration being fed successively at three different levels of water intake. The cellulose levels were superimposed on a highly digestible basal ration.2. It appears that altering the level of water intake, while keeping the ration constant, has only a very limited effect on the level of faecal dry-matter percentage, and on the pattern of variation therein.3. Further evidence is cited in support of the theories, advanced in a previous paper, relating to the influence of fibrous cellulose on water relationships in the digesta and faeces.
The effect of farmyard manure on fertilizer responses
Authors: Boyd D. A. 
Published: March 2009

Farmyard manure affected the response of the potato crop to fertilizers similarly in seven series of experiments (sixty-two in all) at Rothamsted, and in the West Midlands and north of England.In the absence of f.y.m. there were large interactions between each of the fertilizer nutrients, but with f.y.m. the interactions were small. These interactions appear to have been ignored by previous workers, who claimed that N responses ar unaffected by dressings of f.y.m. In fact, f.y.m. increased the response to N applied alone, but decreased the N response where basal P and K fertilizers were also applied. For P the results were similar to those for N.Most of the experimental sites were low in K, and K responses were very large, especially in the presence of basal NP fertilizer. Farmyard manure greatly reduced the response to K, particularly in presence of basal NP fertilizer.A few Rothamsted experiments with f.y.m. and fertilizers and several times of planting showed that the large responses to f.y.m. alone and to fertilizers used in combination (but without f.y.m.) were not reduced by late planting. The result conflicts with previous reports of these data, in which interactions between nutrients were ignored. The combined effect of f.y.m. and fertilizers at late planting was little more than their separate effects, presumably due to delayed maturity, the influence of which would be exaggerated by the early burning-off of haulm in this series of experiments.Most of the experiments were limited to testing fertilizers at two levels (presence and absence), so the effective quantities of nutrients provided by f.y.m. for the crop to which it was applied could only be estimated approximately; the average amounts suggested for normal f.y.m. are 0·3 cwt. N, 0·4 cwt. P2O5 and 0·75 cwt. K2O in 10 tons f.y.m.These results lead to the practical conclusion that, in manuring potato crops on average land, much the same plant food ratios will be appropriate whether or not F.Y.M. is given, and the amount of fertilizer applied can be decreased to allow for the nutrients contained in the f.y.m.
Sweating in cattle. I. Cutaneous evaporative losses in calves and its relationship with respiratory evaporative loss and skin and rectal temperatures
Authors: Taneja G. C. 
Published: March 2009

Three calves (Australian Illawara Shorthorn, Shorthorn and Zebu × Australian Illawara Shorthorn) were exposed to different combinations of wet- and dry-bulb temperatures in a psychrometric chamber at the Physiology Department of the University of Queensland. These animals were 2–3 months old when first exposed to heat.Measurements were made on these animals for cutaneous and respiratory water losses, and skin and rectal temperatures.Cutaneous water losses in all the animals studied increased with increases in air temperature. Comparing these results with those on men with congenital absence of sweat glands exposed to high air temperature below the sweat point, suggests that the cutaneous evaporative losses in cattle are more than those that can be accounted for by diffusionmoisture alone.Increase in cutaneous evaporation under hot conditions is accompanied by increase in skin and rectal temperatures. In the Zebu cross, however, the skin temperature did not rise with rise in air temperature.Keeping the humidity constant, rise in dry-bulb temperature caused increase in respiratory water loss. On the other hand, rising humidity at a constant dry-bulb temperature resulted in decrease in respiratory evaporation. Respiratory evaporative loss was, therefore, greater in hot-dry than in hot-wet conditions.
The efficiency of food utilization for egg production by pullets
Authors: Bolton W. 
Published: March 2009

1. The efficiency of food utilization for egg production by pullets has been determined for two diets, one high in energy and the other low.2. Both groups laid at the same rate (245 eggs/bird) throughout the year.3. Birds fed the low-energy diet ate more food, but the intakes of digestible protein, non-protein digestible energy and metabolizable energy were the same for both groups.4. The cost of food perton was higher for the high-energy diet; per bird per year it was the same for both groups.
A note on the six-course rotation experiments at Rothamsted and Woburn
Authors: Yates F. , Patterson H. D. 
Published: March 2009

The results of an interim examination of the experiments at Rothamsted and Woburn on the effects of nitrogen, phosphate and potash on a six-course rotation of crops are reported.It has become apparent that the main aim of the experiments, to relate the effects of the fertilizers to weather conditions, is not being fully realized. This is in part a consequence of the design, which has inherently low accuracy and results in low responses to phosphate and potash. In addition, faulty randomization and, at Woburn, fertility irregularities and pest damage have further reduced the accuracy attained.The faulty randomization also seriously affects the estimates of experimental error given by deviations from smoothed response curves. Alternative estimates of error are provided to overcome this difficulty.The mean yields and mean standard responses over the period 1931–55 are presented.There is very little year-by-year variation in the responses to phosphate, but the responses to nitrogen and, for some crops, the responses to potash show sufficient variation to justify further analysis. As a first step the regressions of the responses to nitrogen on winter rainfall and on rainfall during the growing season and, for the root crops only, the regressions on sowing or planting date are briefly considered.