bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plane of nutrition and starch equivalents
Authors: Blaxter K. L. , Graham N. McC. 
Published: March 2009

1. Experiments with two sheep are described in which energy retention was measured at different levels of food intake and the losses of energy incidental to food consumption measured.2. Attainment of reasonably stable values for energy losses occurred after 72 hr. of fast. On realimentation stable values were not attained until 10 days had elapsed. Methane production was resumed relatively slowly.3. The accuracy of the mean estimates of energy retention was high, and duplicate determinations of metabolism after lapses of time gave excellent agreement.4. It is shown that the assumption of linearity of the relationship between energy retention and food intake expressed as metabolizable energy is incorrect.5. An exponential relationship between energy retention, and food intake was employed to describe the data. This resulted in a reduction of the residual sum of squares compared with a linear regression.6. It is shown that net energy values (starch equivalents) measured by Kellner, Armsby and Forbes have entirely different meanings, and that the correction employed by Wood reflects these facts.7. The exponential relationship has been generalized to take into account body-size variation and has been examined as far as it affects concepts of efficiency of food utilization, and of nutritional plane.8. Nutritional plane has been rigidly defined in such a way that it is independent of body size and of food quality, and it enables net energy values to be predicted at other planes of nutrition once the net energy value at one nutritional plane is known.9. A simple and rational scheme for the feeding of livestock to take into account the decline in net energy value (starch equivalent) with nutritional plane has been devised.10. Analysis of the energy losses in relation to nutritional plane shows that losses of energy in faeces, urine and as heat per unit food ingested tend to rise with increasing nutritional plane. Methane losses fall. These results suggest that the prediction of net energy values from measurement of energy losses in faeces, or from estimates of metabolizable energy, can give rise to extremely unreliable results.11. The results have been discussed in relation to previous work in this field. It is pointed out that the exponential relationships employed are a convenient method of describing a very complex situation and facilitating its analysis.
The effect on yield and leaf area of wheat of applying nitrogen as a top-dressing in April or in sprays at ear emergence
Authors: Thorne Gillian N. , Watson D. J. 
Published: March 2009

Nitrogen, at the rate of 0.5 cwt./acre, was applied to winter wheat as an April dressing of nitrochalk, or as eight sprayings of 2% NH4NO3 solution applied either to the soil or to the leaves at about the period of maximum leaf area, before and during ear emergence. All three methods of nitrogen application caused similar increases in yield and nitrogen content of grain. April nitrogen gave a greater yield of straw than the later dressings.Late nitrogen application caused a small increase in leaf area index, first noticeable one week after ear emergence and persisting for another four weeks. L.A.I. of plots that received nitrogen in April was much larger than that of the other plots at the period of maximum leaf area, but by four weeks after ear emergence it was less than that of plots receiving the late nitrogen. Shoot number per metre and leaf area per shoot were increased by early nitrogen, but only the latter was increased by nitrogen applied at ear emergence.Leaf area duration after ear emergence was the same on all nitrogen-treated plots and the yield of grain divided by L.A.D. was nearly constant for all plots.Applying nitrogen late, after an April dressing, did not prevent the rapid fall in L.A.I. from the high value reached at the period of maximum leaf area and caused no greater increase in yield than when applied in the absence of an April top-dressing. A single urea spray applied in early June increased yield to the same extent as the ammonium nitrate sprays.
Grazing studies on the Guadalcanal Plains, Solomon Islands. 2. Effects of pasture mixtures and stocking rate on animal production and pasture components
Authors: Watson S. E. , Whiteman P. C. 
Published: March 2009

SummaryAnimal production was compared on three pastures, Brachiaria mutica (para), B. decumbens (signal) and Panicum maximum cv. Hamil (hamil) each sown with a common legume mixture of Centrosemapubescens (centro), Macroptilium atropurpureum cv. Siratro, and Stylosanthes guianensis cv. Endeavour (stylo), at four stocking rates, 1·8, 21·87, 31·86, and 41·85 animals/ha, over 4 years on the GuadalcanalPlains, Solomon Islands.Mean live-weight gain per head over the four stocking rates and 4 years on para pastures was 01·847, on signal pastures 01·838, and on hamil pastures 01·828 kg/head/day. Mean production per hectare at the optimum stocking rates were: para at 3.6 animals/ha, 607 kg; signal at 31·86 animals/ha, 442 kg; hamil at 21·87 animals/ha, 362 kg/ha/year.The high stocking rates of 31·86 and 41·85 animals/ha caused the hamil pastures to decline to the stage where they were destocked in the 4th year of grazing.Superior production on para pastures was not simply related to green dry matter (GDM) on offer. In the 1st year of grazing, GDM was highest in hamil pastures, but in the 2nd year highest in para, and in the 3rd year mean yields were similar in all pastures, but were very low at the 31·86 and 41·85 animals/ha stocking rate in the hamil pastures.Para pastures maintained highest legume contents. The quadratic relationship between live-weight gain/head and legume content was significant over all pastures and stocking rates. Live-weight gain (LWG) per head increased up to 15% legume content, after which there was little change. Yield of green leaf, percentage green leaf, and sward bulk density did not appear to be related to LWG/head. Para pastures had lower values for all these components than the other pastures.Chemical factors contributed to the higher animal production from para pastures. Para leaf maintained consistently higher in vitro dry-matter digestibility values. Na content of para averaged 01·812%, whereas other species were 01·801 to 01·802%, and below the critical level (01·805%) for animal intake. N and S in leaf material, and Cu in total tops were also consistently higher in para grass.Results of this grazing trial suggest that selection of grass species on the basis of quality including dry-matter digestibility and mineral content, on ability to persist with increasing stocking rate, on compatibility with legumes, and on growth habit are more important than selection for dry-matter yield.
Game domestication for animal production in Kenya: an analysis of growth in oryx, eland and zebu cattle
Authors: Carles A. B. , King J. M. , Heath B. R. 
Published: March 2009

SummaryLeast-squares estimates of the parameters of the Bertalanffy growth equation, adjusted for six sources of variation, were obtained for oryx, eland and zebu cattle.Values for asymptotic weight were lower than the mature weights normally given for the species, particularly eland and cattle, owing to management constraints. The figures for females brought into the project were considered the most representative of the species in general. For this category of oryx, eland and zebu cattle respectively, the estimates were as follows: the coefficients of growth rate were 0·136, 0·112 and 0·114; asymptotic weights (W∞) were 146, 277 and 395 kg; and ages at maturity (0·98 W∞) were 33, 41 and 39 months. For females born on the project estimates of birth weights were 14·5, 24·1 and 28·7 kg; and of ages at zero weight were 3·55, 3·80 and 5·18 months prepartum, for oryx, eland and zebu cattle respectively.When differences in size, and therefore metabolic rate were discounted, oryx grew at 3·2, eland at 3·1 and zebu cattle at 3·4 g/kg W∞0·75/day. Comparison with mean values for water turnover (ml/l0·82/day) on the same project revealed that oryx used about one third of the water required by eland and cattle, for the same amount of growth (g/kg W∞/day).Significant sources of variation for W∞ were species, sex, and mode of entry into the project (capture or birth), all at P < 0·005. Season of birth was also significant at P < 0·01, with oryx born 2 months before a wet month achieving the largest W∞ whereas the highest average growth rate occurred when birth was 1 month before a wet month. The only significant source of variation obtained for growth rate was year of entry (P < 0·005).
Nodulation and nitrogen accumulation in field beans (Vicia Faba L.)
Authors: Igwilo N. 
Published: March 2009

SUMMARYThe effects of plant population density, defoliation and removal of pods and apical buds on dry matter, nodulation and nitrogen accumulation in field bean (Viciafaba L.) were investigated in the field in 1973 and 1974.In 1973 seed yield, dry matter and nitrogen accumulation were similar at 50 and 150 plants/m2 while in 1974 40 plants/m2 was significantly different from 80, 120 and 160 plants/m2 which were similar in these attributes. At similar densities, these crops generally had similar leaf areas and nodule weights/m2 during the early pod-filling period while at earlier growth stages leaf area and nodule development were greater at the higher plant population densities. Leaf area and nodule weight per plant were positively correlated as were absolute growth rate per plant and nitrogen assimilation rate per unit weight of nodule.Substantial leaf removal reduced weight but not the nitrogen assimilation rate of nodules determined from plant nitrogen content. Leaf removal did not significantly reduce dry matter but reduced nitrogen yield by reducing seed yield provided that the removed leaves were accounted for.Pod removal reduced dry-matter and nitrogen yield as well as nitrogen assimilation rate of nodules. Pod removal, however, substantially increased number and weight of nodules. Most of these late-formed nodules were located on the older parts of the lateral roots. Removal of the shoot apex had minor effects on nitrogen yield but reduced nodulation towards the completion of pod-filling.
Experiments on the treatment of parasitic gastritis in sheep and lambs
Authors: Wood W. A. 
Published: March 2009

The results of these experiments are, on the whole, disappointing, since they have failed to reveal a reliable treatment for parasitic gastritis of sheep other than that caused by H.contortus, but they do confirm the experiments of other workers in that there are several drugs available which are more or less effective against this worm. Of these perhaps copper sulphate would seem to be in many ways the best for general use, since it is cheap and safe, and can be easily given either dry in capsules or in solution. Better results are obtained when two doses are given, and probably the interval of 7 days between the doses could, with advantage, be shortened to one or two days. The addition of sodium arsenite did not, in these experiments, increase the efficacy of the copper sulphate.Carbon tetrachloride, given in 12 c.c. doses would seem to be effective againstHaemonchus. In such doses it is rather expensive, and although in these experiments toxic symptoms were not observed, deaths from smaller doses have been recorded by others.Tetrachlorethylene (Nema) given in capsules containing 5 c.c. gave, in most cases, good results againstHaemonchus, and except in Sheep 10 reduced the egg count very considerably. It did, however, cause considerable constipation, and in a few instances post-mortem examination revealed some inflammation of the small intestine. The administration of a laxative with or shortly after the Nema therefore appears to be indicated.
Studies on the storage of potatoes. III. The composition of the atmosphere in a potato clamp
Authors: Crook E. M. , Watson D. J. 
Published: March 2009

The CO2concentration in the atmosphere of a potato clamp varied between 0·06 and 0·86%. The sum of CO2and oxygen concentrations remained approximately constant at 21%. The CO2concentration increased with time from December to April. This was attributed to increase in the rate of respiration of the potatoes caused by rise of temperature. Wind blowing in the direction normal to the face of the clamp reduced the COa concentration, presumably by causing external air to flow through the clamp coverings. A multiple regression of CO2concentration on temperature of the potatoes at the time of sampling, and on the mean component of wind velocity normal to the clamp face estimated over a period of 3 hr. before the time of sampling, accounted for 64% of the variance between sampling occasions.Unsaturated compounds were detected in the clamp atmosphere by absorption in bromine; the concentration of these, expressed as ethylene, varied between 0·004 and 0·025%.The magnitude of CO2accumulation and oxygen depletion in the clamp atmosphere was too small to produce effects of practical importance on the storage behaviour of the potatoes. If the unsaturated compounds were ethylene, the concentration present was sufficient to cause appreciable retardation of sprouting.
Studies on soil phosphorus. II. The nature of native and residual phosphorus in some South Australian soils
Authors: Williams Colin H. 
Published: March 2009

A study of residual phosphorus in soils resulting from the use of phosphate fertilizers has been made, using a simplification of Ghani's method for the fractionation of soil phosphorus.In cultivated soils all the residual phosphorus was extractable by successive extractions with 2·5% acetic acid-1% 8-hydroxyquinoline and 0–1 N-sodium hydroxide, and practically all had remained in the inorganic form; very little, if any, change in organic phosphorus was recorded as a result of the application of superphosphate.In pasture soils (uncultivated) the application of phosphatic fertilizers brought about an increase in both inorganic and organic phosphorus and, in addition, some of the applied phosphate may have entered a form not extractable by the two extractants. The increase in organic phosphorus was not directly proportional to the amount of phosphate applied, as were the increases in the extractable inorganic fractions. It tended to approach a constant value, irrespective of amount and nature of the phosphate applied.
The effect of thermal stress on the acid-base balance of the Ayrshire calf
Authors: Bianca W. 
Published: March 2009

1. Two 4-month-old Ayrshire calves were subjected in a climatic room for periods of 2½–4½ hr. to an atmosphere having a temperature of 35° C. and an absolute humidity of 34 mg./l.2. This treatment resulted in an increase in respiration rate, a decrease in carbon dioxide tension and carbon dioxide combining capacity of the venous plasma, an increase in the lactic acid concentration of the venous blood and an increase in the pH of the urine. The pH of the venous plasma showed only a slight tendency to increase.3. It is concluded that thermal panting under the conditions described caused a carbon dioxide deficit which was just compensated for by the excretion of alkali by the kidneys, and that this compensation was not substantially influenced by the production of lactic acid resulting from an increased activity of the respiratory muscles.
A survey of beef production in west wales, 1943–8 Part I. Regional production
Authors: Phillips R. 
Published: March 2009

1. The structure of the cattle population (4 June returns), as well as of cattle sales to the Ministry of Food, have been illustrated.2. The trends in cattle production show the definite changes from that of the traditional storestock rearing to that of milk selling.3. A considerable part (38·2%) of the total graded animals slaughtered for beef are the ‘wastage’ animals from the breeding and dairying herds.4. Reference has also been made to the high proportion of ungraded cows (36·7% of the total cows) purchased by the Ministry. The ungraded cattle, however, are only 17% of the total sales. On the other hand, the ungraded ‘wastage’ cattle contribute 90% of the total ungraded cattle.5. More heifers than steers were sold for slaughter, and it has been shown that the average live weight of the graded steers is nearly 224 lb. heavier than that of the heifers.
Studies on the metabolism of fowls: II The effect of activity on metabolism
Authors: Deighton Thomas , Hutchinson J. C. D. 
Published: March 2009

An investigation of the metabolism of a number of Light Sussex cockerels has shown that there exists a rhythm in the metabolism during fasting amounting to about 9% as between morning and night observations, the former being the higher by the percentage stated.Two methods were adopted to exclude the effect of variation in the activity of the birds at different times of day. In the first, the birds were artificially stimulated during the normal period of repose in such manner as to give periods of approximately equal activity by day and by night. In the second, the movements of the birds were recorded by a system of “point scores”, and regression equations were deduced from a large number of such experiments so as to make it possible to reduce the metabolism observations to a basis of zero activity.The results obtained by these two methods of procedure were in good agreement with one another.The metabolism in thestandingposition is 40–45% above that in the sitting position, a figure considerably above that for the increase of metabolism as between the lying and standing positions usually found in quadrupeds, while at the moment of rising the heat output may occasionally be trebled, but averages about cent per cent above sitting. The former of these observations is of importance in estimating food requirements as our experiments show that generally speaking rather more than 12 out of each 24 hr. period is spent standing when the birds are kept in cages. It follows that the sitting metabolism must be increased to allow for this when the figure is being used for computation of rations. The large heat increase on rising to the standing posture is of such short duration as to exert little influence on the mean metabolism over a 24 hr. period.
Experiments on cutting potato tubers
Authors: Bell G. D. H. , Gilson M. R. , Dillon Weston W. A. R. 
Published: March 2009

1. Field experiments on the use of cut ware setts with the potato varieties Arran Banner, King Edward and Majestic have shown that with proper handling no loss in plant establishment need result. When the cut setts are planted at the same distances as whole setts, there is liable to be a reduction in the yield per acre because of the lower yield per plant, but the actual rate of increase may be increased considerably by cutting because of the larger number of plants obtainable.2. No benefit has been found from the practice of dusting the cut surfaces of tubers of Majestic with slag, lime or ashes, while adverse effects resulted from the use of a fungicide and alum.3. The exposure of cut setts to drying conditions lowers their resistance to attacks by micro-organisms, and encourages the breakdown of the tuber flesh by bacteria of the carotovorum group.4. In general, the use of certain fungicides, either directly on the cut surface, or as a means of moistening sack coverings, is not to be recommended because of the adverse effects of the fungicide on the natural resistance of the live tissue of the tuber flesh.
Factors affecting the digestion of oesophageal fistula samples and hay samples in nylon bags in the rumen of cattle
Authors: Playne M. J. , Khumnualthong W. , Echevarria M. G. 
Published: March 2009

SUMMARYFactors affecting the nylon-bag technique, for examination of digestion in the rumen of extrusa and hay samples of low nutritional value, were studied. Effects of: the method of placement of bags in the rumen; saliva in extrusa; drying and milling techniques; a second-stage digestion with acid-pepsin solution; sample size; and losses of particulate matter through bag cloth were studied. Digestion of dry matter (d.m.) and cell walls after 12, 24, 48, 72 and 168 h in the rumen were used to indicate treatment effects.Attaching bags with nylon cord to a weight was a better method than enclosing them in perforated jars in the rumen which restricted digestion. Drying technique had little effect on digestion, although frozen extrusa was digested more than oven-dried feed, especially in samples of Heteropogon contortus. Chewing of forage was sufficient to obtain maximum rates of digestion. Milling extrusa through 1 or 2 mm screens did not increase digestion. An extra period of digestion in acid-pepsin solution increased digestion of feed samples more than that of extrusa, but the effects were small. It reduced between-bag variation slightly, but did not alter the significance of differences between treatments. The effect of sample size on digestion was small. Sample weight (3, 6 and 9 g) was kept proportional (42 mg/cm2) to bag cloth area.Digestion of d.m. after 24 h reflected digestion of cell walls. Digestion of cell walls was faster in grasses than in legumes. The higher digestibility of legumes was due to solubilization within 24 h of the greater amounts of cell contents found in legumes. Cell contents were only partially solubilized, and up to 10 g per 100 g original d.m. were not removed. Losses of particulate matter averaged 4·6% (range 0·5–10·6%). Losses were high when samples were finely milled (1 mm screen) but varied between species. Pore aperture of cloth was 25 μm. Methods for determining loss and correction of digestion data for such losses are given.
Effects of Date of Sowing on Overwintered Onion Varieties in Pembrokeshire
Authors: Allen E. J. , Jones J. L. , Salter P. J. 
Published: March 2009

SUMMARYData are reported from a 3-year study of the effects of date of planting on yield of overwintered onions. Delay in sowing from mid-August to late September increased plant losses during the winter and decreased yields of ware-size onions. Effects were most severe in early maturing varieties.
The porosity of egg shells, and the influence of different levels of dietary calcium upon porosity
Authors: Tyler Cyril 
Published: March 2009

1. An experiment was performed to consider the porosity of egg shells, and the influence of different levels of dietary calcium upon this factor.2. A method was devised for measuring porosity under standard conditions, and the values so obtained are referred to as porosity coefficients.3. The low calcium diet soon led to the cessation of egg production. The few eggs laid showed a tendency to increasing shell porosity as the end of laying approached. On the average these shells had much higher porosity coefficients than shells produced on a normal calcium diet.4. The high calcium diet had no apparent ill effects on two birds, but the other two laid many abnormal eggs. Porosity coefficients in this group were, on the average, lower than in the normal calcium group, but not significantly so. Egg production was as good as on a normal calcium diet.5. The porosity coefficients were significantly higher in period 2 than in period 1, when birds were fed the normal calcium diet throughout; egg production also fell in the second period.6. Eggs other than the first in a clutch do not differ in porosity, but the first egg has a significantly lower porosity coefficient than the remainder. A possible explanation of this is suggested.