bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary study on the use of different methods for determining the proportion of bacterial nitrogen in the total nitrogen of rumen contents
Authors: Nikolić J. Anna , Jovanović M.
Published: March 2009

Three different methods have been used to estimate the contribution of bacterial nitrogen to the total nitrogen in rumen digesta from calves receiving ground diets containing different levels of digestible energy and in which part of the nitrogen was supplied as urea. The method based on the ratio of 2, 6-diaminopimelic acid (DAP)-N to total N for rumen contents and rumen bacteria was not successful because the bacterial fraction isolated from pooled rumen contents contained a similar concentration of DAP to whole rumen digesta. The main source of error in the method based on the nucleic acid N/total non-NH3-N ratio for whole rumen contents and bacteria was probably the variability in the ratio for bacteria growing under different conditions. The method utilizing differences in the amino acid composition of the diets, a bacterial fraction and rumen content estimates bacterial protein rather than bacterial nitrogen. The chief limitation is the different rate of degradation of different dietary proteins. Bearing in mind these limitations calculations by the nucleic acid method gave mean values of 61–94 % bacterial nitrogen in the total nitrogen of rumen contents 3 h after feeding four different diets. Values recorded by the amino acid composition method varied between 66 % and 82 % bacterial protein N in the total protein N of rumen contents. The proportional contribution of bacteria increased as the digestible energy content of the diet was decreased in both cases. However, since the ruminal total protein N concentration fell as the digestible energy content of the diet was reduced, the actual concentration of bacterial protein N decreased with decrease in dietary digestible energy.
Growth rates of three cassava varieties (Manihot esculenta Crantz) under varying population densities
Authors: Enyi B. A. C.
Published: March 2009

The effect of variety and spacing on growth, development and yield of cassava and the relationship between growth, development and yield in three cassava varieties were investigated during the 1971 and 1972 growing seasons. Msitu Zanzibar outyielded Aipin Valenca and these two varieties in turn outyielded Amani 4026/16. The varietial effect was associated with differences in the rate of bulking. Increase in plant density led to an increase in the yield of tubers per hectare, the mean increase with increasing plant density being greater in Aipin Valenca than in either Amani 4026/16 or Msitu Zanzibar. Increase in plant density from 12000 to 18000 plants/ha led to a decrease in root tuber yield in Amani 4026/16. The calculated optimum density for maximum yield was 6·7, 6·4 and 5·6 plants/m2 respectively for Msitu Zanzibar, Aipin Valenca and Amani 4026/16. The spacing effect on tuber yield was associated with differences in the rate of bulking. Aipin Valenca was usually taller than the other varieties and, in general, increase in plant density increased the height of the plants.

Final total dry matter/m2 was greater in Aipin Valenca and Msitu Zanzibar than in Amani 4026/16 and, with the exception of the last variety, total dry matter/m2 increased with increasing plant density. Total dry matter produced per plant was greater in Msitu Zanzibar than in Aipin Valenca and these two varieties had greater dry weight per plant than Amani 4026/16. In the three cassava varieties, the dry weight per plant increased with decreasing plant density.

A greater proportion of the total dry matter was diverted into the root tubers of Aipin Valenca and Msitu Zanzibar than in Amani 4026/16. Generally, increase in plant density decreased the proportion of total dry matter diverted into the root tubers. Mean crop growth rate increased with increasing plant density while mean net assimilation rate and relative growth rate decreased with increasing plant density. Amani 4026/16 and Aipin Valenca had a greater mean crop growth rate and a greater net assimilation rate than Msitu Zanzibar. Mean relative growth rate was greater in the latter than in the former two varieties.

Leaf area index and leaf area duration were greater in Msitu Zanzibar than in the other two varieties and these tended to increase with increasing plant density.

There was a close and positive relationship between rate of bulking and root tuber yield and the lack of a positive relationship between leaf area duration and tuber yield is discussed.
Further studies on the prediction of the nutritive value of protein for ruminants
Authors: Osman H. Elsayed , Amin B. A.
Published: March 2009

Six successive trials with three adult rams (Sudan desert sheep) were conducted with the main object of finding a suitable index for the prediction of the nutritive value of protein in non-legumes for ruminants.

The mean change in the concentration of ruminal ammonia, blood urea and ruminal V. F. A. 3 h after feeding legumes was considerably greater than after feeding the nonleguminous hays. Among the legumes berseem hay gave the least change in the concentration of ruminal ammonia, blood urea and V. E. A. The leguminous hays produced more gas underin vitroconditions than the non-legumes. Berseem hay produced the greatest volume of gas. Butterfly pea hay and lubia hay gave more or less similar results. Among the non-legumes the desert grasses gave the lowest values.

Of all the feeds studied maize hay gave the highest nitrogen retention, followed by berseem hay. Despite this superiority of maize hay, the overall mean nitrogen retention of legumes was much greater than that of the non-legumes. Among the non-legumes dry desert grasses displayed a negative nitrogen balance.

Regression equations based on the present data indicated that nitrogen retention only of leguminous hays could be always predicted from changes in blood urea concentrations. The present results also showed that the nitrogen retention of non-legumes and to a lesser extent that of all feeds taken together (i. e. legumes and non-legumes) can be assessed by using volume of gas producedin vitro(i. e. rate ofin vitrofermentation).
Effects of fine-particle amendments on the soil moisture characteristics of a gravelly sandy loam and on crop yields
Authors: Stone D. A.
Published: March 2009

Pulverized fuel ash and fiuidized combustor ash were used to modify the availablewater capacity and moisture characteristics of a gravelly sandy loam soil in a study of the effects of fine-particle amendments on crop yield. Intimate incorporation of the ashes into the top-soil at rates of up to 502 t/ha increased the available water retained in the surface 0·3 m of soil by 40–80 %. The increase was mainly water held at potentials of between –0·05 bar and – 1 bar.

Two sugar-beet crops followed by broad beans, salad onions and cabbage were grown in the amended soil. With the highest rate of ash addition yield of the onions was increased by over 30% and of the cabbages by 14%. No improvement in sugar-beet or broad-bean yields resulted from the treatment. Poor growth of the second sugar-beet crop was attributed to a reduced aeration effect but it is suggested that the failure of the increased available water to improve yield consistently in this and a previous experiment was in part caused by rapid evaporative losses from the amended soil.
Factors affecting yield and fertilizer response of sugar beet in Iran
Authors: Bolle-Jones E. W. , Sanei F.
Published: March 2009

Field experiments were conducted in four provinces of Iran in which sugar-beet yield responses to added nitrogen and phosphorus fertilizers were correlated with soil test values and number of irrigations.

Although significant yield responses to fertilizer application were obtained in all four provinces, extremely few significant relationships were established between soil test values and yield response.

Average crop yield was favourably influenced by the number of irrigations applied in Fare and Khorasan, by organic carbon status in Esfahan and Khorasan and adversely affected by increased soil conductivity in Esfahan and Khorasan. These results were taken to imply an inadequate number of irrigations in Fars and Khorasan. The high calcium carbonate status found in Fars soil adversely affected the level of average yield.

Response to nitrogen fertilizer declined in Fars and Khorasan as the leaf nitrogen exceeded 3·15 and 4·0% respectively. Response to phosphate fertilizer declined in West Azerbaijan and Khorasan when leaf phosphorus exceeded 0·4%.
The prediction of the body composition of hill sheep from body weight, red cell volume and tritiated water space
Authors: Sykes A. R.
Published: March 2009

The use of body weight, red cell volume and tritiated water space in the prediction of the body water, body-fat and soft tissue protein contents of hill sheep was investigated. Sixteen Blackface sheep, ranging in age from 2½ to 6½ years, were used before mating in November when in peak body condition and 21, of similar age distribution, were used in mid-lactation in June when in very poor body condition. Mean fat concentrations in the empty body were 188 and 28 g/kg in November and June, respectively.

Body weight alone accounted for 46 and 14% of the variation in body-fat content in November and June, respectively. The inclusion of red cell volume as a second independent variate did not improve the efficiency of the prediction equations. When tritiated water space and body weight were used 77% of the variation in body-fat content was accounted for in both November and June. Separate equations for the November and June groups gave the most accurate estimate of body-fat content, but it was concluded that for most practical purposes a single relationship would be sufficiently accurate. Soft tissue protein content was best described as a simple function of body weight.

The application of prediction equations from the literature to the present populations of sheep led to overestimates of body-fat content by up to 100%. It is suggested that prediction equations need to be specific to the experimental conditions operating or to the particular population under study.
Relative efficiency of urea and urea supergranules for irrigated wheat
Authors: Prasad R. , Singh S.
Published: March 2009

A field experiment was made in rabi seasons (November–April) of 1981–2 and 1982–3 to study the relative efficency of urea and urea supergranules (USG) for spring wheat. USG showed no advantage over prilled urea for spring wheat.
The effect of amount and timing of nitrogen application to drilled crisp lettuce crops on head weight at maturity
Authors: Wurr D. C. E. , Fellows Jane R.
Published: March 2009

Much of the recent increase in crisp lettuce production in the U.K. has been marketed as heavily trimmed solid ‘Iceberg’ heads, wrapped in plastic film. Supermarkets want ‘Iceberg’ lettuce with a minimum trimmed weight of 450 g (Anon. 1983) and consistency of product, but the mean head weight of crisp lettuce at maturity can vary considerably from one sowing to another as a result of environmental conditions earlier in growth (Pew, Gardner & Bessey, 1984; Wurr & Fellows, 1984). In midsummer, some sowings of the most popular variety Saladin can produce larger and heavier heads thanc supermarkets require and the cause of this variation needs to be understood in order to increase the proportion of crops meeting supermarket needs.
The blood composition of Friesian bulls; variations with age and relationships with results of progeny tests
Authors: Stark A. J. , Rowlands G. J. , Manston R. , McClintock A. E.
Published: March 2009

Blood samples were taken from 172 Friesian bulls during 1973–5 on three or four occasions. The bulls were in Milk Marketing Board cattle breeding centres in England and Wales and were from 1 to 14 years of age.

The blood samples were analysed for packed cell volume, haemoglobin, erythrocytes, mean corpuscular volume and glucose, and samples of serum for the concentrations of albumin, total protein, urea-nitrogen, inorganic phosphate, Ca, Mg, K, Na and Cu.

Packed cell volumes and haemoglobin and K concentrations were higher in bulls than those previously recorded in dairy cows. There were significant age relationships for packed cell volume, haemoglobin, albumin and globulin (P < 0·001), inorganic phosphate and erythrocytes (P < 0·01) and Ca and Mg (P < 0·05).

Repeatability estimates were calculated and compared with estimates previously obtained for dairy cows.

On the basis of improved contemporary comparisons of the bulls, there was a significant relationship between the average milk yield of a bulls daughters and the concentrations of urea, inorganic phosphate and K (P < 0·05) in the blood serum of the bull.
Studies on a barley-oats mixture
Authors: Taylor B. R.
Published: March 2009

In three experiments with mixtures of barley and oats, a combination of Midas barley and Karin oats gave consistently higher yields than the mean of the components and slightly higher yields than the better component. The performance of this mixture was maintained over different sowing patterns and seed rates, but where sowing was arranged to give an advantage to one component of the mixture at the expense of the other, mixture yields were less than where both components were closely mixed.

The increased yield of the mixture was attributed to the greater tillering of barley in mixture than in pure stand, brought about by less competition before heading, and to a higher weight per grain of Karin in mixture than in pure stand, a result of its greater height after heading and the favourable disposition of its panicles and upper leaves in the canopy.
The longevity of sodium, potassium and magnesium fertilizer residual effects on the yield and composition of ryegrass grown on a sandy soil
Authors: Bolton J. , Penny A.
Published: March 2009

A field experiment testing the effects of potassium and magnesium sulphates applied from 1960 to 1967 and sodium chloride applied in 1966 and 1967 on a range of crops (Bolton & Penny, 1968) was sown with ryegrass in 1967. Only basal N and P was given to all plots until 1971 when basal K was also applied. The experiment terminated in autumn 1974.

Grass yields were increased by K residues for 3·5 years but overall yields became small due to K deficiency. After giving basal K, residual K no longer increased yields but did slightly increase % K in the grass until the end of the experiment. Some residual K from the 1960–7 dressings was found in the sandy loam soil after the final harvest.

Magnesium fertilizer residues slightly increased grass yields in the 1967–70 period but not later. However, % Mg in the grass dry matter was increased by the residues for the whole 7·5 year period. Exchangeable Mg was also increased in soil sampled after the final harvest, especially in the 23–46 cm subsoil.

Sodium fertilizer residues increased grass yields until the basal K was applied, especially on plots without added K. Significant increases in % Na in the grass and Na uptakes were detectable in all years, i.e. up to 7·5 years after the last Na application. This finding is contrary to most accepted views on the longevity of Na fertilizer effects and could be important in areas where sodium deficiencies in cattle and sheep occur.

Increases in % Cl in the grass from the sodium chloride were only detectable in the first two cuts in the year following the final application.
Lamb mortality in a flock of East African Blackheaded sheep
Authors: Trail J. C. M. , Sacker G. D.
Published: March 2009

1. The effects of birth weight, sex, twinning, parity of dam and dry season on mortality rates of lambs were studied between birth and weaning at 20 weeks in a flock of East African Blackheaded sheep.

2. The mean birth weights of non-surviving lambs were lower than those of surviving lambs. Singles from gimmers and twins from ewes were 0.5 and 1.0 lb., respectively, lighter at birth, and had higher mortality rates than singles from ewes. The overall mortality rate of singles from ewes was 16%, singles from gimmers 20% and twins from ewes 28%. Male and female lambs born alive had similar mortality rates (18%).
An evaluation of pasture quality with young grazing sheep. II. Chemical composition, botanical composition and in vitro digestibility of herbage selected by oesophageal-fistulated sheep
Authors: Grimes R. C. , Watkin B. R. , Gallagher J. R.
Published: March 2009

1. In a grazing experiment with sheep, cocksfoot, rye-grass and tall fescue were grown with and without white clover, under ‘short’ and ‘long’ management systems.

2. One sheep on each plot was fitted with an oesophageal fistula, from which herbage samples were collected at fortnightly intervals. The botanical composition of samples from the mixed swards was estimated by an optical point quadrat method. Samples were analysed for crude protein and cellulose, and digestibility was estimated in vitro.

3. Treatment difference within the mixed swards were not significant in terms of botanical composition. The mean proportions selected were 73% grass, 9% clover and 18% dead matter. The proportion of clover selected did not differ significantly between sample collections.
Estimation of the proportion of C3 and C4 plant species in the diet of animals from the ratio of natural 12C and 13C isotopes in the faeces
Authors: Jones R. J. , Ludlow M. M. , Troughton J. H. , Blunt C. G.
Published: March 2009

The relation between the ratio of the natural 12C and 13C isotopes of carbon in the feed and resultant faeces of animals was studied to develop a technique for estimating the proportion of C3 species (tropical legumes) and C4 species (tropical grasses) selected by grazing animals.

In general, theδ13C values (see text for definition) of faeces from rabbits, sheep, goats and cattle were lower (more negative) than those of the corresponding feeds by from 0·4 to 2·0. This was possibly due to contamination in the gut by tissues or fluids with lower δ13C values. When C4 and C3 feeds were alternated, cattle took about a week to fully achieve the new level (δ13C of – 28·7 on the C3 feed and – 13·1 on the C4 feed) in the faeces. This time lag is associated with the time taken for the feed to move through the digestive tract.

When mixed C3 and C4 feeds were fed to rabbits, sheep, goats and cattle there was a negative linear relation between percentage legume (C3) in the feed and the δ13C of the faeces (P < 0·01). A decrease in one unit in the δ13C value was associated with an increase of 7·0–8·5% legume in the diet.

Estimation of the percentage legume in the feed from the δ13C value of the faeces and of the C3 and C4 components of the diet, resulted in a consistent over estimation of the legume component because the faeces had lower values than the corresponding feeds. This bias was removed if the prediction was based on the δ13C of the feeds minus 1 unit; the legume percentage in the diets of the sheep, goats and cattle could then be estimated with a precision of about ± 5%.

Differences in digestibility between the C3 and C4 components greatly bias the estimations. This bias in the diets fed to rabbits was effectively removed by using in vitro organic matter digestibility values of the two components to correct for the differences. Legume percentage in the diet could then be estimated with a RSD of ± 3%.

Advantages and disadvantages compared with alternative methods of estimating the diet of grazing animals are discussed.
Experiments comparing ‘break crops’ as a preparation for winter wheat followed by spring barley
Authors: Prew R. D. , Dyke G. V.
Published: March 2009

Oats, clover, beans(Vicia)and maize were tested as ‘break crops’ in three experiments on land cropped frequently with wheat or barley. Barley was used as a ‘no-break’ control treatment. Test crops were winter wheat followed by spring barley; they received N-fertilizer at four rates. After barley wheat had much take-all(Gaeumannomyces graminisvar.tritici); all the break crops decreased the take-all effectively and equally. Other soil-borne diseases were unimportant. N-fertilizer required for best yields was less, by 100 kg N/ha after clover and by 50 kg after beans, or maize, than after barley or oats. Best yields after oats, beans, clover were respectively I·O, 1·2, 1·4 t/ha better than after barley. Differences in take-all explain much of these effects. Ploughed-in trefoil did not affect take-all but gave small increases in yield. Percentage N in wheat grain was increased by fertilizer-N; it was greater after barley, maize or clover than after oats. Effects on the following barley, except those of N-fertilizer, were small.
Animal production studies in Jamaica: I. Introduction
Authors: Nestel B. L. , Creek M. J.
Published: March 2009

A descriptive background is given to a group of beef farms in Jamaica on which a series of grass and animal production studies were carried out using technical and economical data derived from those farms over a 5-year period. During this time the farms co-operated in keeping standardized costaccounts and recording detailed outputs from farms and from improved and unimproved lands within those farms. Studies were made of the economics of pasture improvement and also of improvement in husbandry and breeding programmes. The possible value of the results to the small farms in the area is discussed.
Effect of soil moisture on nodulation of cowpea and hyacinth bean
Authors: Habish H. A. , Mahdi A. A.
Published: March 2009

Pot experiments in which cowpea and hyacinth bean were grown at 15–45% soil moisture showed that nodulation, nitrogen fixation and plant growth were poor at 15%. The weights of nodules and plants were lower in January (winter) than in June (summer). In June cowpea was more tolerant of dry conditions giving good nodulation at 25–35% whereas hyacinth bean required 35–45%.

Under field conditions the number and dry weight of nodules were affected by the irrigation interval whereas plant growth was affected by the amount of water applied. Applying 75 mm depth of water every 7 days gave the best combination of nodulation and plant growth.
Foetal stunting in sheep: 2. The effects of high ambient temperature during gestation on wool follicle development in the foetal lamb
Authors: Cartwright G. A. , Thwaites C. J.
Published: March 2009

Hotroom treatment of ewes during the last two-thirds of gestation resulted in the birth of lambs which were significantly lighter than lambs born to nutritionallydeprived ewes. Neither high temperature nor undernutrition had significant effect on the density of either primary or immature secondary wool follicles, but the total number of mature secondary follicles tended to decline in the lambs from unheated ewes as the level of nutrition declined, and was significantly reduced by a further 30 % in the hotroom group.

In a second experiment, heated and unheated ewes fed to appetite were compared with unheated ewes pair-fed to the hotroom level of feed intake. High temperature had no apparent effect on maternal wool growth, but did reduce total wool follicle number in new-born lambs by approximately 50%. This effect was most marked with respect to mature secondary follicles (only 18% of unheated mean), less so in immature secondaries (56% of unheated mean), and barely discernible amongst primary follicles (93% of unheated mean). None of the differences in follicle numbers between the two unheated groups was significant.

The results suggest that the effects of high temperature on wool follicle development in the sheep foetus are akin to those of extreme undernutrition.
Diurnal variation in the chemical composition of plasma from lactating beef cows on three dietary energy intakes
Authors: Coggins C. R. E. , Field A. C.
Published: March 2009

Twenty-two beef cows, producing on average 5·5 kg 4% fat corrected milk per day, were offered diets of rolled barley and silage such that eight animals were consuming 70%, seven 95% and seven 120% of their estimated energy requirements. Blood samples were taken at intervals during the day and the plasma concentrations of glucose, free fatty acids (FFA), ketone bodies, total protein, albumin, globulin, urea nitrogen, calcium, inorganic phosphate, magnesium and copper determined.

Diurnal variation was found in the plasma concentration of glucose, FFA, ketone bodies, urea nitrogen, albumin, calcium and magnesium; it was particularly marked for the first four constituents and appeared to be related to feeding.

There were no overall significant differences between groups in the mean daily concentrations of the measures of energy status (glucose, FFA, ketone bodies), but significant (P < 0·001) prefeeding group differences were found in glucose and ketone body concentrations. No significant differences between groups were found for the remaining constituents.

There was a postprandial depression in plasma glucose concentration, which was positively correlated with FFA concentration.
Interrelationships between different chemical components in mixed rumen bacteria
Authors: McAllan A. B. , Smith R. H.
Published: March 2009

Mixed rumen bacteria entering the duodenum of a ruminant are a major source of some of the nutrients required by the animal. A number of values for the chemical composition of mixed rumen bacteria have been reported and a few observations made on interrelationships between different components at different times after feeding (Hoogenraad & Hird, 1970; Jouany & Thivend, 1972; Bird, 1973; Smith & McAllan, 1973; Czerkawski, 1975; McAllan & Smith, 1974, 1976). There is also some published information on in vivo variations in the storage carbohydrate in mixed rumen bacteria with different diets (Jouany & Thivend, 1972; McAllan & Smith, 1976) but no information on interrelationships between such variations and changes in other components in the bacteria.

The present paper reports a study of such interrelationships in bacterial samples, containing wide ranges of storage polysaccharide (α-dextran) and crude protein concentrations, obtained from steers given a wide variety of diets.
The pollination requirements of oil-seed rape (Brassica napus L.)
Authors: Williams Ingrid H. , Martin A. P. , White R. P.
Published: March 2009

The pollination requirements of three cultivars of winter and one of spring swede rape (Brassica napus), grown in a glasshouse, were compared. All cultivars yielded more when hand-pollinated than when auto-pollinated but were self-fertile and yielded equally well whether self- or cross-pollinated. In most cultivars plants that were shaken to simulate movement of plants by wind yielded more than autopollinated plants and not significantly differently from hand-pollinated plants. Handpollinating and shaking plants also increased the set of early flowers.
Residual effects of potassium fertilizer
Authors: Ridgman W. J. , Jones J. L.
Published: March 2009

In a long-term experiment on a boulder-clay soil Ralph & Ridgman (1981) found that the response of potatoes to freshly applied K fertilizer was independent of the amount of K that had been applied during the preceding 10 years. The greatest yield was obtained from plots which had received the greatest amount of K during the preceding 10 years together with the optimum amount of freshly applied K (120 kg K/ha in this case) and the addition of an extra 60 kg K/ha to plots which had received less K previously did not increase the yield. Similar benefits from residual K had been reported by Johnston, Warren & Penny (1970). In view of the continuing disagreement about the need for applying K to cereals on boulder-clay soils it was decided to attempt to quantify these effects more precisely.
Studies on the adaptation of the rumen to the hydrolysis of biuret in cattle
Authors: Kondos A. C.
Published: March 2009

Studies on the adaptation of cattle to the hydrolysis of biuret and on the response of rumen ammonia level to the introduction of 50, 100 or 150 g of feed-grade biuret showed that (1) the rate of ruminal adaptation to the hydrolysis of biuret increased to a maximum effective level of about 350 mg/24 h/100 ml within 10 days when a readily available energy source was fed, (2) a single dose of 50, 100 or 150 g/day of biuret was associated with a prolonged increase of rumen NH3 concentration. The magnitude of the increase was 8–9 mg/100 ml for every 50 g of added biuret, (3) adapted rumens retained their biuretolytic activity for several weeks, and responded to the re-introduction of biuret into the diet by increasing to a near maximum rate within 24–48 h.
Biuret and urea in maintenance and production diets of cattle
Authors: Kondos A. C. , Mutch B.
Published: March 2009

A series of five field trials with cattle was carried out to study the comparative efficiency of utilization of urea and biuret in various maintenance and production nutritional situations. It was shown that in maintenance diets with energy intake above 8 Meal/head/day and where half of the nitrogen requirements of the animals was contributed by one of the two non-protein nitrogen (NPN) sources, biuret was utilized 30% more efficiently than urea. No difference in the degree of utilization of urea or biuret was apparent when the energy was reduced to 6·7 Meal/head/day. On the other hand, a high intake of nitrogen in production rations had a masking effect on the nitrogen contribution of the NPN sources and no significant differences in bodyweight gain were recorded.
Effect of seasonal temperature on the yield and chemical composition of a lucerne-timothy mixture
Authors: Hamilton Herman A. , Dermine P. P. , Hidiroglou M.
Published: March 2009

1. The yield and mineral composition of a timothylucerne mixture at different stages of maturity were determined in selected growing periods under the climatic conditions of Northern Ontario.

2. An alteration in temperature from cool to warm or from warm to cool conditions appeared to favour increased forage production, but the rate of increase in dry-matter yields declined more under cooler conditions.

3. Forage yields obtained on a second cutting increased with delayed harvesting of the first cut, and yield reductions from an early harvest were not economically compensated for by increased yields of dry matter of the second cutting.
Rumen fermentation of herbage in sheep receiving carbohydrate supplements
Authors: Christian K. R. , Williams V. J.
Published: March 2009

Concentrations of rumen volatile fatty acids, ammonium and protein nitrogen and free microbial count in groups of sheep fed fresh herbage have been compared with concentrations in groups supplemented with pure carbohydrates.

Rumen ammonia concentrations in sucrose and cellulose-supplemented sheep tended to be lower before feeding than in sheep fed herbage only, but this difference disappeared after feeding. Ammonia concentrations in sheep supplemented with starch, and those receiving herbage only were similar before feeding, but the rise after feeding was less for the starch-supplemented group. The rise in volatile fatty acids after feeding was greater when part of the herbage was replaced with an equal weight of dry matter of starch, but lower when replaced with ucrose or cellulose.
A comparison of the effects of prilled urea, used alone or with a nitrification or urease inhibitor, with those of ‘Nitro-Chalk’
Authors: Rodgers G. A. , Penny A. , Hewitt M. V.
Published: March 2009

Prilled urea, with or without a nitrification inhibitor (dicyandiamide, DCD) or urease inhibitor (hydroquinone), was compared with ‘Nitro-Chalk’ as a nitrogen fertilizer for winter oil-seed rape in field experiments on a clay loam soil at Rothamsted in 1984 and 1985. Each was tested when supplying 50 kg N/ha to the seed bed; each was also broadcast in early spring to supply 150 kg N/ha as either a single dressing or two equal dressings, the form of nitrogen being the same as that applied in the seed bed.

Seed-bed nitrogen increased plant growth during autumn and winter in both years but increased yield only in 1985.

Scorching of plant leaves was severe in spring after application of urea or urea plus DCD given as a single dressing, but was much less with urea plus hydroquinone or when the dressings were divided. DCD inhibited nitrification of fertilizer nitrogen but had little effect on yield compared with urea alone. Ammonia volatilization losses were reduced by urea plus hydroquinone but, irrespective of the type of fertilizer applied, loss was always less than 3% of the nitrogen applied. Soil pH rose rapidly after urea application and thereafter fell slowly, whereas pH fell immediately after application of ‘Nitro-Chalk’. Neither dicyandiamide nor hydroquinone affected the pH changes after urea application. Overall, grain yields from urea were 90%, whereas those from urea plus hydroquinone were 97%, of those obtained from ‘Nitro-Chalk’. Dividing the spring dressings of urea-nitrogen increased yield in 1985 compared with a single dressing, but not in 1984. Yields from divided and single dressings of ‘Nitro-Chalk’ were similar. Oil and protein yields generally showed the same patterns of response to the fertilizer treatments as were shown by grain yields.
Variation in the complete diet composition given during the winter period to an autumn-calving herd
Authors: Kroll O. , Owen J. B. , Whitaker C. J.
Published: March 2009

Autumn-calving cows on a complete diet system were given a similar amount of concentrates over two winter periods in the years 1980–1 and 1981–2. Two feed allocation systems were examined: step (different diets given at different stages of lactation) and uniform (one single diet given over all the winter period).

The yield of fat-corrected milk (FCM) was similar (P > 0·05) in both systems with 5·32 and 5·37 t/cow for the step and uniform system respectively in the 1st year and 4·75 and 4·35 t/cow in the 2nd year.

There is an indication that adult cows or cows with a higher potential for yield can respond to the higher energy concentration diet given in early lactation but with the main effect on milk, not in FCM yield.

No effect of diet distribution was found on overall weight gain but cows given the uniform system lost less weight in early lactation and this may lead to better conception for cows in such a system.
Variation in the electrophoretic band pattern of tuber proteins from somaclones of potato
Authors: Smith D. B.
Published: March 2009

The soluble tuber proteins of potato (Solatium tuberosum) may be separated by electrophoresis on the basis of charge or molecular weight (Stegemann & Schnick, 1982; Maier & Wagner, 1981: Park et al. 1983). Considerable cultivar specific variation exists in the band patterns of these proteins and separation of native proteins in 6% polyacrylamide gels at pH 7·9 has been used as the basis of characterizing cultivars for the Index of European Potato Varieties (Stegemann & Schnick, 1982).
The response of grass-clover and pure-grass leys to irrigation and fertilizer nitrogen treatment. I. Irrigation effects
Authors: Reid D. , Castle M. E.
Published: March 2009

1. In an experiment conducted at the Hannah Institute the effects of irrigation and fertilizer nitrogen treatments on four sward types were studied for 3 years. The swards were S 23 perennial rye-grass with S 100 white clover, S 23 rye-grass alone, S 37 cocksfoot with S 100 white clover, and S 37 cocksfoot alone.

2. The irrigation treatments were—a control (no water) treatment, and two treatments which were irrigated to planned deficit levels of 2 or 0·5 in. below field capacity.
Effect of varying static and changing moisture levels during incubation on the mineralization of carbon in soil
Authors: Ekpete D. M. , Cornfield A. H.
Published: March 2009

The extent of mineralization of organic carbon (carbon dioxide production) during incubation at 28° C. of a sandy loam was determined (a) over 6–12 weeks at varying static moisture levels over the range from air-dried to waterlogged, (b) over a second 6-week period after changing soil moisture level, maintained at various moisture levels during the first 6-week period, to 50% saturation or to waterlogging.
Some comments on the shape of the gain–stocking rate curve
Authors: Connolly J.
Published: March 2009

In this paper the method proposed by Jones & Sandland (1974) for testing the linearity of the animal gain–stocking rate relationship is examined. It is shown that the method cannot be used to establish such linearity. An examination of the biases in estimation of optimum stocking rate and gain per animal and per unit area at the optimum stocking rate arising out of assuming linearity where the true relationship was quadratic led to the following conclusions. Quite large biases can arise. Selection of stocking rates straddling the true optimum reduces these biases. If experimental stocking rates are lower than the true optimum stocking rate the optimum stocking rate is overestimated and the animal gain at optimum is underestimated and vice versa if the experimental stocking rates exceed the true optimum rate.
Experiments on the effect of hormone weedkillers on sugar beet
Authors: Byford W. J. , Prince J.
Published: March 2009

MCPA and 2,4-D sprays at up to 1/20 the dosage normally vised for weed control in cereals severely distorted sugar beet, which subsequently grew at near normal rate but remained distorted. The severity of symptoms and yield depression depended on the stage of growth of the beet when sprayed. Sugar-yield loss was greatest when plants were sprayed at the 6–8 leaf stage.
Removal of phosphorus and potassium from the soil in wheat and barley straw
Authors: Withers P. J. A.
Published: March 2009

The median concentration of phosphorus and potassium in a total of 867 samples of wheat and barley straw at harvest in England in 1986–88 was 0·07% P and 1·00% K in the dry matter. Variation was significant between years and between crop species. The concentration of potassium in wheat and barley straw increased with increasing rate of applied nitrogen at 60% of the sites where this was tested. The results have been incorporated into practical recommendation systems for farmers.
Effect of adding water to paspalum (Paspalum dilatatum) hay on the feed intake of sheep
Authors: Leibholz Jane
Published: March 2009

Low quality roughages are a major feed resource for ruminants in Australia and many other parts of the world. Factors limiting the intake of these roughages include their high cell wall component and low crude protein content. Palatability may also be important. Low quality roughages are frequently dusty. Hence, the present experiment was initiated to determine whether water would affect the intake of paspalum hay (Paspalum dilatatum).
Response of rice yields to irrigation and drainage at two phases of growth
Authors: Farah S. M.
Published: March 2009

In the Sudan, rice has been grown since 1905, but on only a very limited acreage, and information about methods of production are lacking.

With the introduction of a large number of rice varieties into the country (Moir, 1965, 1966, 1967, 1968), an irrigation and drainage experiment was initiated by Hack (1968) at Kenana Research Station (KRS). Using the variety H.D.41, he found no advantage from very short watering intervals (1–3 days) in the early stage of growth, i.e. up to the boot stage, whereas better results were obtained from watering every 6 days in the early stage, to obtain a large number of flowers, and every other day in the late stage, to obtain relatively low sterility and large grains.
Flower and pod production at various nodes of Phaseolus vulgaris L.
Authors: Tayo T. O.
Published: March 2009

In a glasshouse study, the pattern of flower and pod production at the various flowering nodes of Phaseolus vulgaris (cv. 344) was mapped out. Soft X-radiation techniques were also used to study the development of retained and abscissed pods at the various nodes while varying levels of flower or pod removal were used to study the modification to pod development at each flowering node following organ removal.

The period of flower opening over the whole plant spanned an average of 12 days and 90% of the pods retained to maturity were formed from flowers opened within 4 days of anthesis. The terminal inflorescence produced most of the flowers on the plant (25%), but nodes 2 and 3 developed the bulk (50%) of the pods retained. Only 30% of the open flowers on the plant formed pods that were retained to maturity.

Pod elongation was initially very rapid in the pods to be retained, following successful fertilization, with the latter period of pod growth devoted almost entirely to seedfilling. A slow growth rate characterizes the development of abscission in Phaseolus pods and the number of seeds per pod is determined later in pod growth.

Flower or pod removal prolonged flowering and led to longer leaf retention and more branches on the main stem. The number of mature pods was lower on the treated plants and the more severe the removal the larger were these treatment effects. Plants compensated for fewer pods by having more seeds per pod but these were not enough to prevent significant depression of seed dry weight per plant by the most severe removals. Flower or pod removal led to a shift of emphasis in pod production by the plant from nodes 2 and 3 to other areas of the plant where natural wastage of flower and young pods is high.
Effect of seed rate and application of N fertilizer on grain yield and N uptake of rice under intermediate deepwater conditions (15–50 cm)
Authors: Reddy M. D. , Ghosh B. C. , Panda M. M.
Published: March 2009

In an intermediate deepwater (15–50 cm) situation, the number of tillers increased with increase of nitrogen fertilizer from 0 to 40 and 80 kg/ha and of seed rate from 100 to 200, 300 and 400 seeds/m2. The tiller mortality due to higher water depth was higher under no-N treatment and under higher seed rates. The number of panicles and grain yield increased significantly with increase in N. Similarly, an increase in the seed rate increased the number of panicles and decreased the number of grains per panicle and panicle weight. The grain yields of the different seed rates were similar. The interaction between N levels and seed rates was not significant.
Chemotaxis ofCicer Rhizobiumstrains to root exudates of chick pea (Cicer arietinumL.) genotypes and their interaction response on nodulation, nodulins, leghaemoglobin and grain yield in calcareous soil
Authors: Rai R. , Prasad V.
Published: March 2009

TwoRhizobiumstrains were studied for their chemotaxis, nodulation, nitrogenase activity and other endosymbiotic N2-fixing characteristics with two genotypes ofCicer arietinum. Root exudates were found to attractRhizobiumstrains. Nodule-specific root proteins (nodulins) and leghaemoglobin were found to be host-range specific between two strains ofCicer Rhizobium. Physiologically active iron content was more important for nodule functioning than total iron concentration of nodules.
Effects of nitrogen fertilizer applied to seed crops on seed yields and regrowth of progeny tubers in potatoes
Authors: O'Brien P. J. , Allen E. J.
Published: March 2009

Three experiments, carried out in 3 years (1972–5), which examined the effects of a wide range of rates of nitrogen fertilizer applied to seed crops of Home Guard on seed and progeny crop growth are reported. There was little effect of increasing rate of N application over the range 0–300 kg/ha on seed yield, and the results suggested that very low rates of nitrogen fertilizer (< 75 kg/ha) were required for maximum seed yield in mid-Wales. Increasing the rate of nitrogen fertilizer above 304 kg/ha delayed growth and decreased yield in seed crops. Although increasing the rate of nitrogen fertilizer in seed crops delayed senescence and increased the nitrogen concentration of tubers, there were few consistent effects on sprouting or growth of progeny crops.

Close negatively quadratic relationships were found between the dry-matter content of tubers and their size. The dry-matter content of all sizes of tubers increased during growth, but there were no effects of nitrogen on dry-matter content.
Genetic conservation of rare British sheep: the Portland, Manx Loghtan and Hebridean breeds
Authors: Hall S. J. G.
Published: March 2009

Pedigree analyses were conducted of the Portland, Manx Loghtan and Hebridean sheep. These breeds are kept in small flocks, usually with only one ram active. Total population, and number of flocks have grown since registration started in 1975. Gene flow among flocks arisesfrom transfers of rams and of ewes: about 70% of breeding rams and 40% of breeding ewes have been transferred. Between half and three-quarters of the 1984 lamb crop were measurably inbred. More ram lambs are registered than would be expected in commercial practice.

About a third of flocks supplied rams to other flocks showing that these breeds do not have a very hierarchical structure. There is, however, a tendency towards hierarchical structure in the Manx Loghtan. A high proportion of the animals registered as foundation stocks in the earlyyears of the Combined Flock Book were represented in the pedigrees of recent lamb crops, i.e. genetic conservation has, on the whole, been achieved.
Adaptation of Medicago rigidula to a cereal–pasture rotation in north-west Syria
Authors: Abd El-Moneim A. M. , Cocks P. S.
Published: March 2009

The ley-farming system (integrated cereal and livestock production in which cerealsrotate with self-regenerating pastures) is considered to be of great potential benefit to north Africa and west Asia. In the colder parts of this region (of which north Syria is typical) its application is limited by poor adaptation of commercial medic cultivars (mainly Medicago truncatula and M. littoralis). An extended selection programme hag identified M. rigidula as adapted to the soils and climate of the region but nothing is known of its adaptation to the ley-farming system itself.

An experiment which included 23 selections of M. rigidula and one each of M. rotata and M. noeana was conducted over 3 years during which herbage production, seed yield, and the fate of seeds were observed during the 1st year when pastures were established, the 2nd year when wheat was sown, and the 3rd year when the pasture regenerated. Of the 400–800 kg seed/ha produced in the 1st year an average of 87% remained in the soil in spring of the 3rd year. The weight of seed regenerating in the 3rd year varied from 30 to nearly 170 kg/ha, and herbage production, especially in winter, depended heavily on the number of regenerating seedlings. The most productive regenerating pastures produced nearly 2 t/ha of dried herbage by 1 January, and more than 6 t/ha for the whole growing season.

The results showed that there was sufficient residual and newly produced seed at the end of the 3rd year to be sure that subsequent regeneration would result in similar herbage yields in the 5th year, and that the pasture was assured of long-term persistence. The significance of this for livestock production is discussed, and it is concluded that the results should encourage further investigation of grazing management and socioeconomic factors seen as constraints to introducing the ley-farming system to north Syria.
Estimation of genetic differences between Mashona bulls from different production systems using an animal
Authors: Khombe C. T. , Hayes J. F. , Tawonezvi H. P. R. , Khombe M.
Published: March 2009

This paper reports genetic differences between 20 Mashona bulls from smallholder farms, 14 from Makoholi Research Station, three from commercial farms and two reference sires, in Zimbabwe. An animal model, fitted through the derivative free Restricted Maximum Likelihood program (DFREML), was used to analyse 707 birth weight and 623 weaning weight records. Both the mean breeding values of the reference sires and the ranch bulls were significantly (P < 0·05) higher than the mean breeding values of smallholder bulls for birth weight (by 1·6 and 1·7 kg, respectively) and weaning weight (by 10·4 and 11·0 kg, respectively). However, seven of the 20 bulls from smallholder farms were among the top 45% of bulls with high breeding values for both birth and weaning weight. The mean breeding value of bulls from Makoholi was not different from any of the other groups, for all traits studied. It was proposed that future efforts to form nucleus herds to improve the weaning weights of indigenous cattle should include the genetic pool in smallholder farms.