bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnesium metabolism in the dairy cow. II. Metabolism during the spring grazing season
Authors: Rook J. A. F. , Balch C. C. 
Published: March 2009

1. Three experiments are reported in which magnesium metabolism trials were carried out with milking cows that had been changed abruptly from typical winter rations to herbage cut freshly from swards at an early or at a more mature stage of growth and fed in the stall.2. The intake of herbage magnesium by individual animals varied from 9·5 to 15·2 g./day. Much of this variation was, however, associated more with differences in the palatability and dry-matter content of the herbage offered than with individual differences in appetite.3. The mean proportion of the ingested herbage magnesium excreted in the faeces was similar in all three experiments, being 82·3, 83·0 and 82·4% respectively. With any given sward there were, however, wide variations between individual animals in their utilization of herbage magnesium.4. The supply of ‘available’ magnesium to animals fed cut herbage in the stall varied from 0·5 to 4·2 g./day, as compared with values of from 2·6 to 10·5 g./day obtained previously (Rook et al. 1958) with cattle fed typical winter rations. In spite of this lower intake of ‘available’ magnesium, the animals maintained a positive magnesium balance.
Effects of fertilizers and dung on potatoes
Authors: Reith J. W. S. , Inkson R. H. E. 
Published: March 2009

Field experiments were carried out in north-east Scotland on potatoes to measure the responses to, and the two-factor interactions between, nitrogen, phosphate, potash and dung, and have given the following results:1. The responses to nitrogen, phosphate and potash are quite variable from centre to centre, but the mean results show moderately large increases to all three nutrients.2. The mean responses to both nitrogen and phosphate are the same in the presence as in the absence of dung. The response to potash is reduced by two-thirds in the presence of dung.3. There is a general trend for both nitrogen and potash to increase the linear component of the response to phosphate and vice versa. Nitrogen and potash show practically no interaction effects.4. Dung produces a considerably larger increase in yield in the absence than in the presence of fertilizers.5. The nitrogen and potassium contents of the tubers show appreciable effects of the nitrogen, potash and dung treatments.6. Suitable fertilizer dressings are suggested for potatoes grown in the absence and presence of dung.
The influence of four levels of feeding on the position and eruption of incisor teeth in sheep
Authors: Wiener G. , Purser A. F. 
Published: March 2009

The distance between the front of the incisor teeth and the front of the maxillary pad (incisor bite measure) was measured in 140 sheep about 1 year old. The sheep consisted of seven breed types—the offspring of Blackface ewes by Wiltshire, Border Leicester, Lincoln and Blackface rams, and of Welsh ewes by Welsh, Wiltshire and Suffolk rams. Within each breed type the effects of four different feeding treatments lasting 7 months were studied. These produced small but very significant differences in bite measure. Differences between breed types were significant only in respect of the division between the two breeds of dam. Effect of breed of dam, however, was confounded with any effect due to differences in origin.The proportion of permanent central incisors which had replaced milk teeth when the animals averaged a little more than a year old was affected both by the level of treatment during the experiment and by breed.
The apparent digestibility of crude protein by the ruminant: IV. The effect of crude fibre
Authors: Glover J. , French M. H. 
Published: March 2009

The role of crude fibre in modifying the general equation relating the digestibility coefficient of crude protein to the percentage of crude protein in the dry matter of a feed is described.It is shown that for normal average food-stuffs the effect is slight and that for all practical routine purposes the original equation will provide satisfactory estimates of the digestibility coefficient when only the crude-protein content of the dry feed is known.On the other hand, when exceptional feeds are encountered, particularly those in which the crudefibre/crude-protein relationship is abnormal, then more accurate estimates of the digestibility coefficient of crude protein can be obtained from the modified equation which is described above.
Further studies on fishmeal and the hatching rates of hen's eggs
Authors: Coles R. 
Published: March 2009

Reference is made to the depression in hatching rates occasionally recorded when fishmeal is fed to breeding hens. In a previous communication this depression was tentatively ascribed to the presence of aerobic sporing bacteria, support for this theory being given by the high early death-rate from yolksac infection in the chicks hatched from the affected pens. In this experiment samples of white fishmeal from widely separated points of origin were employed. With one group of birds extreme hatching depression was recorded; in one other group a moderate depression was found. Bacterial assays showed that only one sample contained aerobic sporing bacteria capable of coagulating yolk and the count was not high. But the birds fed this sample were those manifesting the mild depression in the hatching rate and this was the only group to show an appreciably above normal early death-rate in the chicks. The major cause of death was yolk-sac infection, and it is concluded that in this group the presence of aerobic sporing bacteria was partially responsible for the depression in hatching, but that the degree of contamination was not as high as that which probably occurred in the previous year.The hatching rate in all groups was inversely related to the depth of coloration in the fishmeal samples. The theory is advanced that, as a result of overheating during manufacture, degradation of the proteins occurred giving rise to toxic products which in turn led to a high embryonic death-rate during the last 4 days of incubation. The highest embryonic death-rate in total, and during this period, was found with those birds fed the fishmeal with the darkest colour. The egg production in all groups of birds was high and it therefore seemed improbable that overheating had proceeded to the stage of materially damaging the essential aminoacid contents of the meal, for it seems widely accepted that if the amino-acid level is sufficient for egg production it is sufficient for good hatchability.
Studies on some sources of variation in carrot root weight
Authors: Salter P. J. , Currah I. E. , Fellows Jane R. 
Published: March 2009

SUMMARYFive investigations were carried out to determine the magnitude of root-size variation within crops of cv. Chantenay Supreme grown under competitive and non-competitive conditions, and to study possible sources of inter-plant variation.In the first experiment root-size variation from crops grown at a high population density (245 plants/m2) and at a low density (25 plants/m2) were compared over a 21-week period from sowing. The c.v.s of root weight were always higher from the high density than from the low density over the harvesting period from 11 to 21 weeks after sowing, and ranged from 74 to 94% and from 50 to 63%, respectively. A second study showed that even with a very low population density (3 plants/m2) the c.v. of root weight at harvest was 58%. The third study showed that 40% of the root weight variation was accounted for by the time of seedling emergence. The results of a pot experiment indicated that when the size of seed, sowing depth, rooting medium and time of seedling emergence were made as uniform as possible, a very uniform population of roots was produced with a c.v. of root weight of 32%. In the final field experiment when time of seedling emergence, seed size and spatial distribution of the plants were the experimental variables, the results confirmed the importance of variability in time of seedling emergence and seedling size in creating variation at an early stage of growth.The results of these studies indicate that competition per se was not a prime source of variation in root size but magnified any initial variation within the crop at the time of seedling establishment. The importance of this early establishment phase in determining the spread of root-size distribution within a crop is discussed together with the factors which influence the time of seedling emergence and seedling size.
Changes in the concentration of plasma proteins in intensively bred ewes
Authors: Mackie W. S. 
Published: March 2009

SUMMARYThe mean concentration of plasma albumin in 30 Finnish Landrace x Dorset Horn ewes subjected to intensive breeding decreased as the number of pregnancies increased from three to seven; it also changed significantly within a pregnancy. Gamma globulin concentration was not affected by the number of pregnancies but decreased significantly within a pregnancy. Total plasma protein was affected like albumin by the number and stage of pregnancy.Plasma volume increased by 23 % in the latter third of pregnancy.
Seasonal growth patterns in field beans (Vicia faba) as affected by population density, shading and its relationship with soil moisture
Authors: Sprent Janet I. , Bradford Alison M. , Norton C. 
Published: March 2009

SUMMARYField experiments, usingVicia fabacvs Herz Freya and/or Maris Bead were made in 1972–5. Population densities were varied and shading treatments were applied. Soil moisture content was monitored throughout. Maximum dry-matter production per plant and per unit area were similar in 1973 and 1974, but lower in 1975. Variations in growth were associated with variations in soil moisture content. When pods began to fill, plants reached maximum total water content and root growth ceased.Increasing density enhanced, and shading retarded both leaf senescence and seed maturation. Maximum potential seed yield (5–6 t/ha) in 1974 was obtained at 32plants/m2. In 1975, yields of 7–9 t/ha were obtained at 66 plants/m2, probably as a result of retention of many pods by the plants. Since total dry-matter production was lower in 1975 than in 1974 we conclude that photosynthetic potential did not limit yield in the earlier year.From the patterns of rainfall, soil moisture and plant water content, we suggest that water supply may be a more important factor controlling yield than either solar radiation or plant competition, with the period following pod setting being especially vital. At this time plant water requirement may often be in excess of supply.
Simulation study of three adjustment methods for the modified augmented design and comparison with the balanced lattice square design
Authors: Lin C. S. , Poushinsky G. , Jui P. Y. 
Published: March 2009

SUMMARYThree adjustment methods using control plots to adjust for soil variation in a modified augmented design (Lin & Poushinsky, 1983) were studied by simulation. The results show that adjustment by design structure (row and column correction factors) is best when soil variation is relatively uniform in one or two directions, while adjustment by regression analysis is best when the variation is multi-directional. Adjustment using the control plot as a fertility index is least satisfactory. A modified augmented design in a replicated experiment is generally inferior to a balanced lattice square design but is competitive when the percentage of environmental variation attributable to soil factors is less than 70% of the total variation.
The effects of breed, breeding system and other factors on lamb mortality: 3. Factors influencing the incidence of weakly lambs as a cause of death
Authors: Woolliams Carol , Wiener G. , Macleod N. S. M. 
Published: March 2009

SUMMARYThe incidence of lamb mortality from weakness at birth, underdevelopment, exposure and starvation was examined over 6 years in an upland flock and analysed in relation to breed, breeding system and other factors. These causes accounted for more than a quarter of the deaths and contributed to many more.The frequency of death due to these causes was greater in lambs light at birth. The incidence of these causes of death differed significantly between the breeds, Scottish Blackface, Cheviot and Welsh Mountain and their crosses, but for the separate categories breed variation was significant only for the incidence of death by starvation, which was also less frequent in cross-breds than purebreds. Mortality from several of these causes was increased by inbreeding (25–59%), but decreased by crossing inbred lines. Lambs born to line-cross or other non-inbred dams had a relatively low incidence of these various causes of death. For underdeveloped lambs variation due to maternal inbreeding was significant. When classes were adjusted for difference in birth weight, breed variation in mortality was greatly enhanced but variation due to inbreeding much reduced.Slightly more twins than single-born lambs died from these causes and triplets fared worst, but such variation was significant only for death from exposure. Mortality from these causes varied significantly with parity of dam, being highest in the first, and mortality in males was slightly but not significantly higher than in females.
Maize yield as affected by irrigation and evapotranspiration control treatments
Authors: De R. , Rao Y. Y. , Ikramullah M. , Rao L. G. Giri 
Published: March 2009

SUMMARYMaize yield was increased by the application of organic mulch (6 t/ha). Mulched plots treated with any of the antitranspirants (kaolin or alachlor) and receiving two or four irrigations yielded as much as untreated plots receiving four or six irrigations. Cob length, number of grains and grain weight of maize were increased by mulching and by the transpiration suppressants. Irrigation water-use efficiency was improved by evapotranspiration control treatments.
The nutritive value of the forage peaPisutn arvensecv. ‘Rosakrone’ for laying hens
Authors: Davidson J. , McFadyen Morag , Milne E. 
Published: March 2009

SUMMARYThe nutritive value of a new forage pea (Pisum arvense), commercially available as ‘Rosakrone’, was assessed by feeding the seeds in ground form to laying hens as a supplementary source of protein in diets based on mixed cereals. Like other pulse seeds they were found to be relatively deficient in methionine. The effect of this on egg production was overcome by adding synthetic methionine to the diet.However, there was also present an anti-nutritive factor, similar in action to that found in other pulse seeds, which caused live-weight loss and reduced the rate of lay to about 0·85 of normal in 20 weeks with 40% pea meal in the diet. This anti-nutritive factor appeared to be heat stable.
Copper deficiency of sheep in eastern Saudia Arabia
Authors: Chamberlain A. G. , Clarke S. H. 
Published: March 2009

SUMMARYThe tissue copper concentrations of Black Najdi sheep at the Hofuf Agricultural Research Centre (HARC) are reported. Lambs suffering from a delayed neonatal ataxia had low concentrations of copper in blood, liver and kidney, consistent with a diagnosis of copper deficiency, which was supported by histological examination of their brains and spinal cords.Low concentrations of copper and high concentrations of molybdenum and sulphate in forages produced at the HARC appear to contribute to the high incidence of neonatal ataxia observed there.The parenteral administration of 40 mg of copper to pregnant ewes improved the viability and weight increases of lambs over lambs born to untreated control ewes, even though all lambs had received an injection of 20 mg of copper soon after birth.The provision of supplementary barley to the lambs running with their mothers and with access to lucerne hay increased their growth and blood copper concentrations over animals restricted to the hay diet.The blood copper, haemoglobin and packed cell volumes of lambs born to ewes maintained on Rhodes grass were significantly lower than lambs born to ewes given lucerne, all ewes having received copper during pregnancy. This effect was attributed to the low copper and high molybdenum and sulphate content of Rhodes grass (Chloris gayana).
The effect of stage of maturity on the yield and chemical composition of oats for haymaking
Authors: Nicholson I. A. 
Published: March 2009

1. Ayr Line Potato oats was studied in the later stages of development for 3 years under upland conditions in Kincardineshire, Scotland. Some major changes in yield and chemical composition of the crop and certain effects of haymaking have been demonstrated.2. In each year, between the ‘milky’ stage and full ripeness of the grain, the growth curve falls into the distinct phases of growth, maturity and senescence when dry-matter loss occurs. The position of the peak yield in terms of stage of maturity varies from year to year.3. Percentage crude protein is low throughout, falling to a minimum after the early ‘milky’ stage and rising again to a maximum at the last cut. Yield of crude protein is highest at the last cut in one year and at the penultimate cut in two years.4. Percentage crude fibre tends to decrease with increasing maturity, while crude fibre yield is low at both extremes of the experimental period.5. More detailed chemical analyses at different stages of maturity show total ash content to be low. The content of calcium is especially poor.6. Separation of the whole of the aerial part of the plant into leaf, stem and inflorescence shows that chemical constituents are being actively re-distributed throughout the plant during the experimental period; with the exception of crude fibre and calcium all constituents estimated tend to be concentrated in the grain with advancing maturity.7. In one year, dry-matter losses during curing range from 22 to 7% at the first and last cuts respectively, while corresponding figures for crude protein are 18 and 10%.8. In the absence of digestibility data and feeding trials under Scottish conditions, the tentative conclusion is drawn that in the higher rainfall areas of the north and west where the crop is most likely to be used, cutting between the late ‘milky’ and late cheesy' stages should give optimum results.9. Attention is drawn to the need for caution in the general application of the results.
Effects of radioactive phosphate fertilizers on yield and phosphorus uptake by ryegrass in pot experiments on calcareous soils from Rothamsted
Authors: Mattingly G. E. G. 
Published: March 2009

1. Two factorial pot experiments with ryegrass grown on calcareous soils from adjacent long-term experiments on Hoosfield, Rothamsted, are described. The effects of the method of application of phosphate, of the amounts of saP tested and of the level of phosphate applied are discussed with special reference to the manurial history of the soils.2. Yield and total phosphorus uptake by ryegrass were slightly greater in the early stages of growth when superphosphate was applied as a powder than when an equal amount of phosphate was applied in solution, but this effect disappeared in later cuts of grass. Total phosphorus uptake was not significantly altered by the levels of 32P tested, and yields were only significantly decreased at one sampling date in one experiment. Uptake of fertilizer phosphorus decreased and ‘A’ values increased, however, in both experiments at the higher rates of application of 32P.3. The addition of fertilizer phosphorus, as superphosphate or monocalcium phosphate, increased the uptake of soil phosphorus by ryegrass on all soils on which there was a yield response to phosphate. The recovery of fertilizer phosphorus, estimated radiochemically, was less, therefore, than the increase in phosphorus uptake by the crop on the soils on which there was a yield response to phosphate fertilizers.4. ‘A’ values were determined on all soils and were shown to be almost independent of two- and five-fold increases in the amount of labelled phosphate tested. ‘A’ values were related to the previous phosphate manuring of the soils and increased by about one-third of the difference in phosphate content on soils that had received heavy applications of superphosphate or farmyard manure over 50 years ago. The ‘A’ values of soils that had recently received superphosphate in the field decreased in 3 years by more than the amount of phosphate taken up by the crops. ‘A’ values of soils that received rock phosphate in the field were lower and did not decrease with time.
Studies on the production of volatile fatty acids from grass by rumen liquor in an artificial rumen: II. The volatile fatty acid production from dried grass
Authors: John A. , Barnett G. , Reid R. L. 
Published: March 2009

1. A study has been made of the production of volatile fatty acids obtainable from dried grass and its gross water-soluble and water-insoluble separates, in the artificial rumen, over two growing seasons.2. In contradistinction to fresh grass, the dried grass gives a consistent production of acetic acid proportionately greater than propionic acid, at all stages of maturity, but when aqueous extracts of the dried grass, and the resultant extracted grass, respectively, are examined separately in the artificial rumen, it is found that the former yield preponderating amounts of acetic acid while the latter give amounts of propionic acid equal to, or exceeding, the corresponding productions of acetic acid.3. An examination of the titration curves for the total acids obtained from the dried grass, extracted grass and grass extract runs, indicates an approach to an incomplete relationship between the residual carbohydrate in the extracted grass and cellulose, while the grass extract reveals itself as the chief source of acetic acid in the whole dried grass, the acid being formed very speedily at the start of the run.4. The suggested sources and some of the possible metabolic pathways involved in the formation of v.f.a. from grass are discussed in the text.
Studies on the production of volatile fatty acids from grass by rumen liquor in an artificial rumen: III. A note on the volatile fatty acid production from crude fibre and grass cellulose
Authors: John A. , Barnett G. , Reid R. L. 
Published: March 2009

1. The findings presented in two previous papers on the yields of volatile fatty acids, obtained by the action of rumen liquor in the artificial rumen, from fresh grass, dried grass and the water-soluble and water-insoluble separates of the latter, have been amplified by a consideration of the acids similarly obtained from specimens of chemically prepared crude fibre and cellulose, from four of the dried grass specimens.2. The proportions of different volatile fatty acids from grass crude fibre and grass cellulose resemble those obtained from cellulose powder, propionic acid being produced in greatest relative yield.3. A general review of these latter findings, in relation to those already presented, has been given.