bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical treatments for increasing the digestibility of cotton straw: 1. Effect of ozone and sodium hydroxide treatments on rumen metabolism and on the digestibility of cell walls and organic matter
Authors: Ben-Ghedalia D. , Shefet G. , Dror Y. 
Published: March 2009

SUMMARYThe digestibility and rumen metabolism of diets containing as 50% of their organic matter (OM), cotton straw (CS) untreated, treated with sodium hydroxide and treated with ozone, were studied in sheep cannulated in the rumen and at the duodenum with simple cannulae. The concentration of total volatile fatty acids (VFA) in the rumen of sheep given the ozone and NaOH treatments was higher than in the untreated diet; however, the VFA profiles were not different. The rumen dehydrogenase activity, suggested to reflect general microbial activity, was higher by 83 and 81% in the ozone and NaOH treatments respectively, than in the untreated.Apparent digestibility of organic matter in the ozone-treated diet was 74·6%; 1·25 and 1·17 times higher than in the untreated and NaOH-treated diets respectively. The calculated values for organic matter and cell-wall digestibilities of the cotton straw in the complete diets were: 30·0, 20·0; 60·8, 60·0; and 39·6, 39·7%, respectively, for the untreated, ozone and NaOH-treated cotton straw. Nitrogen metabolism was not impaired by the presence of formic acid in the ozonated cotton straw; the apparent absorption of N from the intestine and the apparent digestibility of N were higher in the ozonetreated diet than in the untreated or NaOH-treated diet.The proportion of organic matter and cell walls digested in the rumen was higher in the NaOH and ozone treatments than in the untreated, and the possible reasons for that are discussed. A positive relationship was found between cell-wall digestion in the rumen (% of intake) and the rate of passage (% per h) of particulate matter from the rumen. The interpretation of this relationship is discussed in general and in view of the results of the present study.
Digestibility of rumen bacterial cell proteins in buffaloes and goats
Authors: Verma D. N. , Singh U. B. 
Published: March 2009

SUMMARYThe digestibility of protein of mixed whole rumen bacterial cells and Streptococcus bovis were determined in Bos bubalis and goats. The bacterial cells were labelled either with 35S or 14C in vitro incubation and were injected in a single dose into the rumen after protecting by formaldehyde treatment. Faeces were collected for 6 consecutive days and radioactivity excreted in the faeces was measured. The digestibility of bacterial protein ranged from 81·7 to 96·8% in both the species.
The relationship between nitrogen supply and the nitrogen yield of cut grass swards
Authors: Richards I. R. , Hobson R. D. 
Published: March 2009

SUMMARYUsing data from 140 experiments conducted at sites throughout England and Wales, a relationship between nitrogen supply and the nitrogen yield of cut grass swards was sought. One linear and three non-linear functions were fitted to the data. The non-linear functions fitted the data slightly better than did the linear and, over the range in nitrogen supply normally found, provided consistent predictions of grass nitrogen yield. The recovery of available nitrogen in the herbage was found to decline with level of nitrogen supply from a potential maximum of 79%.
Some physical properties that affect the rate of diffusion of oxygen into silage
Authors: Rees D. V. H. , Audsley E. , Neale M. A. 
Published: March 2009

SUMMARYExperiments are described which study the effect of density and chop length on the rate of diffusion of oxygen into silage and equations are presented which enable the rate of diffusion to be calculated under laboratory conditions. The concept of zero porosity is also discussed and methods of calculating the density at which it occurs are given. The effect of carbon dioxide on the rate of diffusion is also discussed.
An analysis of cattle live-weight changes on tropical grass pasture during the dry and early wet seasons in northern Australia: 2. Relations to trends in the pasture, diet and grazing behaviour
Authors: McCown R. L. , McLean R. W. 
Published: March 2009

SUMMARYCattle grazing buffel grass pastures during the dry season at Katherine lose large amounts of live weight during a short period following first rain. In Part 1 we showed that these losses were due mainly to reduction in gut contents. Part 2 examines the changes in pasture, diet and grazing behaviour to assess the probable change in nutritional status of cattle following rain.During the dry season the most valuable pasture component, green leaf, was very scarce and had a nitrogen concentration of about 1%. Diets of oesophageally-fistulated cattle contained less than 0·5% N. Shortly after first rain diet N doubled owing both to rapidly increasing amounts of green leaf and to the increase in N concentration in young leaf to over 3%. Although intake was not measured, literature is cited to show that this increase in dietary N would be expected to increase rumen digestion rates with a resultant marked increase in D.M. intake and a reduction in gut contents.Although availability of high quality herbage increased very rapidly following first rain, a period of increased nutritional stress immediately following rain could not be ruled out. However, any such decline in nutrition appears to be short-lived.
Comparison of spring barley varieties grown in England and Wales between 1880 and 1980
Authors: Riggst T. J. , Hanson P. R. , Start N. D. , Miles D. M. , Morgan C. L. , Ford Margaret A. 
Published: March 2009

SUMMARYFive experiments, involving 37 varieties, were carried out over three seasons to estimate the increase in yield potential in spring barley achieved by plant breeding during the last 100 years. Most of the important spring barley varieties grown in Britain between 1880 and 1980 were represented. In three experiments disease was controlled by a fungicide while in the other two experiments fungicide application was a main treatment. To prevent yield loss due to lodging, plants were supported as a main treatment in two trials.In all experiments most of the modern varieties yielded more than the older ones. The genetic gain in yield was 0·39% per year during the 100-year period and 0·84% per year between 1953 and 1980.Modern varieties had higher grain yields, shorter straw, and higher harvest index denned as the proportion of grain dry weight to total above-ground dry weight; more of the tillers they produced survived to give ears. There was a weak association between biological yield (total above-ground dry weight) and grain yield.It is suggested that although much of the improvement in yield described here could be attributed to increased harvest index, the scope for further improvement in this character may be limited. Further yield improvements might be achieved by combining high biological yield with high harvest index.
The effect of weight at mating and of nutrition during mid-pregnancy on the birth weight of lambs from primiparous ewes
Authors: Russel A. J. F. , Foot Janet Z. , White I. R. , Davies G. J. 
Published: March 2009

SUMMARYForty-eight approximately 18-month-old Scottish Blackface ewes were used to study the effects of two levels of nutrition during mid-pregnancy (30–98 days of gestation) on the birth weight of lambs from ewes varying in weight, size and condition at first mating. The mean live weight (42–4 kg), size index (31–9) and condition score (2–4) at mating of the 26 ewes from flock A were all less than those of the 22 ewes from flock B (54–5, 39–4 and 2–9 respectively). Mean intakes of the low and high nutritional treatment ewes during mid-pregnancy were 10–6 and 22–0 g/kg/day respectively of a pelleted diet supplying 8–81 MJ metabolizable energy and 125–5 g crude protein/kg. These intakes produced estimated changes in net maternal weight of approximately – 5 and 0 kg respectively.Mean lamb birth weights from ewes on the low and high nutritional treatments were:flock A, 3–32 and 3–83 kg; flock B, 4–96 and 4–23 kg respectively. Analyses showed intake during mid-pregnancy to have a positive effect on lamb birth weight in the flock A ewes, and a negative effect in flock B ewes. Mating weight accounted for 78% of the variance in birth weight in the low nutritional treatment ewes but had little effect in those on the higher level of feeding.The practical implications of the results are discussed in relation to levels of juvenile nutrition.
The effects of genotype, sex and feeding regimen on pig carcass development: 2. Tissue weight distribution and fat partition between depots
Authors: Kempster A. J. , Evans D. G. 
Published: March 2009

SUMMARYDissection data for 1006 carcasses taken from the first 2 years of the Meat and Livestock Commission's (MLC) Commercial Pig Evaluation (CPE) were used to examine the growth of tissue weights in joints relative to the corresponding total tissue weight in carcass, and the growth of fat depots relative to total fat over the carcass weight range, 46–92 kg. Growth relationships were examined using a linear allometric model. Differences in tissue weight distribution between genotypes (pigs from different companies in CPE), sexes (barrows and gilts) and feeding regimens (restricted and ad libitum feeding) were examined at constant lean, bone or fat weight as appropriate, common allometric regression slopes being assumed.Lean and bone showed the same pattern of development. Relative growth was lowest in the proximal limb joints (ham and hand) increasing inwards to the joints of the back. With minor differences, the same pattern was found for subcutaneous fat and intermuscular fat. Fat depots differed considerably in their growth relative to total fat: intermuscular fat grew more slowly (allometric growth coefficient, b = 0·87), subcutaneous fat at the same rate and perinephric and retroperitoneal fat (flare fat) more rapidly (b = 1·24).Significant differences were recorded between genotypes in lean distribution and in the distribution of fat depots. However, the differences were small and of little commercial importance. There were also differences in fat partition between genotypes, flare fat being the most variable depot.Sex and feeding regimen also influenced tissue distribution and fat partition.The results are discussed in relation to the robustness of regression equations for predicting overall carcass composition from subcutaneous fat measurements and sample joint dissections.
Field measurements of water use for irrigation control in Kenya coffee
Authors: Pereira H. C. 
Published: March 2009

The paper presents the results of 10 years of soil moisture studies in arabica coffee in high altitude tropical conditions. Very deep soils and contrasting wet and dry seasons give unusually favourable conditions for soil moisture measurements.Volumetric measurements on soil cores are reported for 10 ft. depth of soil, which is shown to include most of the root system of arabica coffee, and holds 48 in. of water under field conditions when active drainage has ceased. This is shown to correspond to a soil moisture tension of 1/3 atm. Of the 48 in. of water only 12 are available to plants. Wilting points determined by sunflower seedlings on soil samples to 15 ft. depth are shown to agree well with field sampling under wilting conditions in coffee plantations.A series of seasonal factors relating the water use of the coffee crop to the readings of an evaporation pan are presented, and their application over 6 years is shown to check with soil sampling data within the limits of sampling error. This method is proposed for control of supplementary irrigation under conditions of limited water supply, but a distillation-type radiation integrator can with advantage replace the evaporation pan.The balance of the hydrological equation for this crop is demonstrated in each of the 6 years.
Gamma radiation in the preparation of maize silage for studies on the aerobic deterioration process
Authors: Woolford M. K. 
Published: March 2009

SUMMARYMaize silage was exposed to doses of y radiation varying from 0 to 6 Mrad inclusive and the effects of this treatment on the microflora and possible changes it might impose on the chemical composition were monitored. The highest dose was required to reduce the native population of micro-organisms to an insignificant level and only minor losses of lactic acid and ethanol were sustained. In addition, the irradiated silage was inoculated with representatives of groups of micro-organisms implicated in the aerobic deterioration of silage and the subsequent changes upon exposure to air observed. The inoculum proliferated and induced losses of fermentation acids, water-soluble carbohydrates, dry matter and, to a minor degree, neutral detergent fibre, and resulted in an increase in temperature and total nitrogen, the factors most likely to change during aerobic deterioration. Only the 6 Mrad dose yielded material suitable for investigations into the identification of those organisms primarily responsible for aerobic deterioration.
The potential of maize as a forage crop in Scotland
Authors: Potts M. J. , Waterson H. A. , Rodger J. B. A. , McMartin I. 
Published: March 2009

SUMMARYBetween 1972 and 1976 a series of 15 trials was carried out at various climatically favoured sites throughout Scotland to assess the potential of new hybrid maize varieties of European origin under Scottish conditions. No meaningful differences were found between varieties in respect of dry-matter yield or maturity.Seed rates ranged from 100 to 200 × 103 seeds/ha giving final stands from 40 to 194 × 103 plants/ha. Regression analyses for the variety Dekalb 202 included in 54 treatments indicated that the relationship between plant population density and dry-matter yield was partly linear with an important quadratic function, suggesting an optimum of 179 × 103 (± 80 × 103) plants/ha. Plant population density accounted for 65·9% (P < 0·01) of the variance in dry-matter yield but was not significantly related to dry-matter content.Climatic variation between years had no overriding influence on growth and development. Dry-matter production for the variety Dekalb 202 sown in mid-May ranged from 2·86 (1972) to 14·54 t/ha (1975) with associated dry-matter contents of 15·1 and 24·1% respectively. In a few instances slightly higher dry-matter contents (maximum 28·6%) from mid-May sowings were associated with lower yields.Neither date of sowing nor accumulated temperature to harvest measured as Ontario Heat Units was significantly related to yield but date of sowing accounted for 29·5% (P < 0·01) of the variance in dry-matter content. Accumulated Ontario Units at harvest were not significantly related to dry-matter content.An interesting relationship between dry-matter yield and the date on which the crop had received 1379 Ontario Units was found. This relationship may be useful in selecting sites at which maize may be grown or to predict maximum potential final yield in any given season.
Response to the use of Merino in improvement of coarse-wool Barki sheep: an analysis of some cross-bred wool traits
Authors: Guirgis R. A. 
Published: March 2009

SUMMARYA study was carried out during three successive years from 1970 to 1972 on different wool types. Breed groups involved were Merino (M), coarse-wool Barki sheep and five of their crosses. Traits studied were greasy-fleece weight, clean-fleece weight, kemp score and means of staple length and fibre diameter in the whole fleece.The heaviest greasy fleeces were produced by ¾ followed by ⅝ M. Total average greasy fleece weight of the crosses was 3·43 kg. There was a general trend of increase in greasy fleece weight with increasing Merino proportion.The total average percentage clean yield of the crosses was 42·2, and ½ M and ¾ M produced the heaviest clean fleeces. The total average clean fleece weight of the crosses was 1·44 kg. Skirting the fleeces caused a reduction in the within-fleece variability of staple length and diameter. Percentages reduction for staple length were 10·3, 9·6 and 14·6 and those for fibre diameter were 2·4, 5·0 and 9·5 in Barki, crosses and Merino respectively.Barki had the coarsest diameter and the whole fleece of ¾ M showed the finest mean diameter of the crosses. The within-staple variability in distribution of fibre diameter was high in Barki and throughout the crosses. The average percentage medullated fibres was highest in Barki and decreased throughout the series of crosses. The ¼ M had the highest frequency medullated fibres of the crosses.The longest mean staple in the crosses was produced by ¼ M. The within-fleece variability in staple length was generally low. In the crosses, the variability assumed slightly higher values than those of the parental breeds.Kemp production was mainly contributed from the dorsal line, particularly from the back and hip.As regards some wool and mutton characteristics, ⅝ M might be considered the most suitable cross-bred type.With increasing Merino contribution in the crosses, the mean fibre diameter showed a decreasing trend, but a high within-staple variability was maintained throughout the crosses. Inter se mating, in most of the crosses, produced animals that showed relatively more uniformity between fleeces than either both or one of the crosses. Inter se mating of the different cross-bred types with selection of the desired uniformity in length and diameter would be recommended.
Determination of ammonia and nitrate in soil
Authors: Bremner J. M. , Shaw K. 
Published: March 2009

1. Methods for the determination of ammonia and nitrate in soil are described. The ammonia and nitrate are extracted at pH 1·0–1·5 with a mixture of potassium sulphate and sulphuric acid, and the ammonia is determined by distillation with magnesium oxide at 25° C. in a modified Conway microdiffusion unit. Ammonia plus nitrate is determined on a separate sample of the same extract by reduction of the nitrate to ammonia with titanous hydroxide and subsequent distillation with magnesium oxide, both the reduction and distillation being carried out in a modified microdiffusion unit at 25° C.2. The methods are applicable to coloured extracts and are not affected by substances found to interfere with other methods of determining ammonia and nitrate.3. It is suggested that the methods may also prove useful for the determination of ammonia and nitrate in plant materials.
A comparison between the mode of sction of organic matter and synthetic polymers in stabilizing soil crumbs
Authors: Emerson W. W. 
Published: March 2009

Synthetic soil crumbs stabilized by the addition of small quantities of a polymer, and natural soil crumbs from old grassland, have been extracted with neutral sodium pyrophosphate and alkali and the strengths of the crumbs compared before and after extraction, using the sodium saturation technique. Three polymers were used: polyvinyl alcohol (a non-ionic polymer), sodium alginate, and a vinyl acetate-maleic anhydride co-polymer (Vama), the latter both carboxylated polymers. Pyrophosphate was able to displace the carboxylated polymers from the synthetic crumbs, but not the stabilizing fraction of the organic matter from the grassland crumbs. 0·5N-NaOH produced a much greater reduction on the strength of the alginate treated crumbs compared with Vama crumbs, which is attributed to the weaker hydrogen bonds formed by the former. Prolonged leaching with alkali removed a considerable part of the stabilizing organic matter in the grassland crumbs. Neither method of extraction affected the stability of the polyvinyl alcohol crumbs.It is concluded that the grassland crumbs are stabilized by the formation of inter-lamellar complexes with the clay in the crumbs, and probably that the substance forming the complexes is a polymer and contains amino-groups.Evidence is also given that phosphate ions and the carboxylated polymers are attached in the same manner to the edges of the clay crystals.
The digestibility of the carbohydrate complex by birds of different ages
Authors: Bolton W. 
Published: March 2009

1. The digestibility of the carbohydrates in compounded poultry diets has been estimated, using both conventional and individual methods for certain components.2. In the conventional analysis, crude fibre was apparently digested to the extent of 5%; this has been shown to be due to the comparison of different complexes in the food and the droppings.3. Sugar and starch were digested by birds of all ages, and cellulose and lignin were indigestible. The digestibility of pentosan increased with increased age of the bird.4. By deleting crude fibre and adopting available carbohydrate for the partition of the carbohydrate complex in foods, the nutritive ratio of a compound diet can be estimated from analytical data, and the amount of extra protein necessary when a diet is supplemented by fat can be calculated.
Energy values in pig nutrition:3. The digestible and metabolizable energy content of barley, wheat, maize, oats and rye
Authors: Wiseman J. , Cole D. J. A. , Lewis D. 
Published: March 2009

SUMMARYThe digestible energy (DE) and metabolizable energy (ME) content of eight samples of barley, eight of wheat, four of maize and two each of oats and rye were determined using growing gilts. The DE content of barley ranged from 15·35 to 15·89 MJ/kg D.M., from 15·15 to 16·42 MJ/kg D.M. for wheat and from 16·05 to 16·47 MJ/kg D.M. for maize. DE values for the two oat samples were 12·48 and 12·74 MJ/kg D.M. and 15–04 and 15–47 MJ/kg D.M. for the two rye samples. There was a significant correlation between DE and ME:ME (MJ/kg D.M.) = 0·050 + 0·965 DE: r = 0·99; P < 0·001.The ratio ME/DE was significantly influenced by crude-protein content:ME/DE = 100–0·254 CP%: r = –0·77; P < 0·001.ME values were also corrected to zero nitrogen retention (MEno) and to 30% nitrogen retention (MEN30). The effect of such corrections was expressed as MEN0/ME and MEN30/ME. Values thus obtained were 0·98 and 1·00 respectively for the pooled values for all cereals.The data indicated that there was unlikely to be significant variation in the DE content of samples of the same cereal species, selected from commercial sources within the U.K. when evaluated under standardized experimental conditions.
A study of mole drainage with simplified cultivation for autumn-sown crops on a clay soil
Authors: Cannell R. Q. , Goss M. J. , Harris G. L. , Jarvis M. G. , Douglas J. T. , Howse K. R. , Grice S. Le 
Published: March 2009

SummaryA replicated, long-term field drainage experiment on a clay soil was started in 1978 to investigate the effects of mole drainage on land that had been direct-drilled or ploughed. We here describe the background and the need for this work, details of the experiment and summarize the results for the first 2 years. The main factors causing point-to-point variability in the soil at the experimental site and their relative contributions were assessed. Variations in inherent soil properties were small, except for depth to calcareous clay. Site hydrology was also generally uniform, especially soil water content, and was little affected by the presence of subsoil drainage schemes dating from the 19th century. There were some variations in micro-relief. The drained and undrained plots were hydrologically separated. Equipment was installed to measure separately surface runoff, lateral flow at the bottom of the cultivated layer (the interflow) and deep drainage from the mole and pipe system (in the drained plots only). The design and performance of that equipment is described. In both years much of the undrained soil became saturated in winter, but a residual cultivation pan limited the effect of the mole drains in 1978–9. In 1979–80, after disrupting the pan, the water table in the moledrained plots was about 25 cm deeper than in the undrained plots, root growth was greater and yield of winter wheat 11% heavier. About 90% of water and nutrients draining from the drained plots were carried in the mole and pipe system. The results on water balance, nutrient losses, crop growth and yield are fully reported in companion papers (Harris et al. 1984; Ellis et al. 1984).