bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of tri-n-butyl phosphate on the drying rate and respiration rate of grass leaves measured in the laboratory
Authors: Harris C. E. , May-Brown R.
Published: March 2009

In laboratory tests tri-n-butyl phosphate applied by spraying as an emulsion at a rate equivalent to 0·25% of leaf fresh weight doubled the drying rate of individual S.24 perennial ryegrass leaves measured at 28 °C, relative humidity 22% and air speed 40 cm/sec. Increasing the rate of application produced no further increase in drying rate. In other experiments the same rate of application stopped respiration of leaves and no resumption of respiration was found in the subsequent 4 days. Comparisons of the dry-matter contents of leaves when removed from the plant and after being allowed to dry for 1 week at 27 °C and relative humidity 80%, indicated that inhibition of respiration resulted in large reductions in dry-matter losses. The potential value of a chemical spray which will both increase drying rate and reduce respiration as an aidto the field drying of grass crops is discussed. While it would be incautious to extrapolate from laboratory tests on single leaves to the field situation, evaluation under more practical conditions is clearly warranted.
Improvements in calcined magnesite as a magnesium fertilizer
Authors: Durrant M. J. , Draycott A. P.
Published: March 2009

A laboratory and glasshouse study investigated whether it was possible to improve the availability of magnesium from calcined magnesite (MgO). Samples varying from largely unchanged magnesite (MgCO3) to overburnt MgO were made by calcining small quantities of magnesite ore for up to 6 h at several temperatures between 500 and 1000 °C in the laboratory. The effect of calcining conditions on weight loss on ignition, particle size distribution, total, water-soluble and NH4+ -exchangeable Mg was determined and results compared with the current commercial oxide and kieserite (MgSO4. H2O).

The results indicated that an oxide could be produced containing nearly double the amount of readily-exchangeable Mg of the oxide used at present. The analysis showed that the most reactive oxide was produced either by burning for 3 h at 700 °C or about half-an-hour at 800 °C, i.e. the minimum time at each temperature for complete conversion of the carbonate to the oxide. Either of these two oxides increased the Mg in plants of the three crops grown in the glasshouse by 0·3% on average, whereas plants given the commercial oxide increased it by only 0·2%. The three crops removed about 70% of the applied Mg from the most reactive oxides but only 50% of the Mg from the commercial oxide. The results of an incubation experiment suggested that burning at 700 °C for 3 h gave a marginally more reactive oxide than the short burn at 800 °C. However, the most reactive oxide produced supplied magnesium at a slower rate than kieserite. This may not necessarily be a disadvantage since most of the soils where Mg deficiency of sugar beet and similar crops is a potential problem need a Mg fertilizer which maintains or gradually increases soil Mg. Thus the improved oxide may bo suitable and a comparison in field experiments of the effects of kieserite and oxides produced under different calcining conditions is needed.
Depot fatty acids of Aberdeen Angus and Friesian cattle reared on hay and barley diets
Authors: Leat W. M. F.
Published: March 2009

Aberdeen Angus and Friesian cattle were reared from 4 months of age to slaughter weight at 18–24 months on either high-barley or high-hay diets. Samples of subcutaneous fat were taken by biopsy at 3 monthly intervals, and the degree of fatness of each animal was estimated ultrasonically prior to slaughter, and by visual inspection of the carcasses.

The barley-fed animals gained weight more rapidly, and fattened more quickly than the hay-fed animals with the Angus being fatter than the Friesian at the same age. The percentage stearic acid (C18:0) in subcutaneous fat decreased with age and was replaced by octadecenoic acid (C18:l) and hexadecenoic acid (C16:l), these changes being more rapid in barley-fed than in hay-fed animals. At the same degree of fatness the depot fats of the Friesians were more unsaturated than those of the Angus, and in both breeds the fatter the animal the more unsaturated was its depot fat.

In the hay-fed cattle the percentage C16:0 in subcutaneous fat increased during the last half of the experiment and at slaughter the percentage C16:0 was significantly higher, and C18:l significantly lower, in all depot fats compared with those of the barley-fed animals.

It is concluded that the fatty acid composition of bovine depot fats is modulated by the degree of fattening, and can be affected by diet.
Relationships between energy intake, nutritional state and lamb birth weight in Greyface ewes
Authors: Russel A. J. F. , Maxwell T. J. , Sibbald A. R. , McDonald D.
Published: March 2009

Individual feed intakes of housed mature Greyface (Border Leicester × Scottish Blackface) ewes were adjusted weekly to maintain plasma 3-hydroxybutyrate concentrations during the final 6 weeks of pregnancy at the following values: treatment 1 (adequately nourished; 17 ewes) less than 0·7 mmol/1; treatment 2 (moderately undernourished; 15 ewes) at about 1·1 mmol/1; treatment 3 (severely undernourished; 15 ewes) at about 1·6 mmol/1.

The mean energy intakes (MJ metabolizable energy (ME)/day) required to maintain the prescribed nutritional states in single- and twin-bearing ewes were: treatment 1, 14·3 and 16·3; treatment 2, 10·6 and 11·6; treatment 3, 8·1 and 10·0 respectively.

The moderate degree of undernourishment had no significant effect on the birth weight of single lambs, but reduced the birth weight of twins by 8·2%, while the more severe undernourishment reduced the birth weights of singles and twins by 21·5 and 25·8% respectively.

Foetal energy requirements, estimated by regression analysis, appeared to decrease from more than 2 MJ ME/kg/24 h at 35 days prepartum to 1·54 MJ ME/kg/24 h in the week before parturition.

The amounts of energy required to sustain the nutritional states of treatments 1–3 in non-pregnant ewes were calculated to be 348, 271 and 231 kJ ME/kg0.75/24 h, compared with a maintenance requirement, determined in this experiment, of 344 kJ ME/kg0.75/24h.

It is concluded that in individually fed ewes a nutritional state characterized by plasma 3-hydroxybutyrate concentrations of 1·1 mmol/1 would constitute an acceptable compromise between an uneconomically high energy input and an excessive reduction in lamb birth weight.
Bone weight distribution in steer carcasses of different breeds and crosses, and the prediction of carcass bone content from the bone content of joints
Authors: Kempster A. J. , Cuthbertson A. , Jones D. W.
Published: March 2009

Dissection data for 753 steer carcasses from 17 breed-type × feeding system groups were used to examine the distribution of bone weight between 11 standardized commercial joints, and the prediction of bone content in side (half carcass) from the bone content of individual joints. Breed types included Ayrshire, Friesian, Friesian × Ayrshire and crosses out of Friesians by Angus, Charolais, Hereford, Limousin, Simmental and South Devon sires. Group means for bone weight in the side ranged from 14·9 to 21·0 kg with a pooled within-group S.D. of 1·97 kg.

The increase in bone weight in each joint relative to that in the side was examined using the allometric equation. Pooled within-group growth coefficients (b values) were lowest for the leg (hind shin) and shin (fore shin) joints (b = 0·86 ± 0·02 and 0·94 ± 0·02 respectively) and highest for the sirloin (b = 1·10 ± 0·05).

At equal total bone weight, there were significant (P < 0·001) but relatively small differences between groups in the weight of bone in each of the joints tested.

Bone weights in the top piece, shin and coast joints gave the most precise prediction of bone weight in the side: the pooled within group residual standard deviations were 0·62, 0·67 and 0·71 kg respectively. The limited variation between groups in bone weight distribution was reflected in the robustness of common prediction equations across groups.
Time of application of farmyard manure and fertilizer nitrogen on the growth, yield and nutrient uptake of dryland wheat
Authors: Singh R. K. , De R. , Turkhede B. B.
Published: March 2009

Experiments made for 4 years in the seasonally dry period of the monsoon environment of north-west India showed that the application of farmyard manure (FYM) with the onset of monsoon rains (in early July) was more advantageous for the growth and yield of wheat than its application at the end of the monsoon season in mid-September. Fertilizer N drilled into the soil with the cessation of rains was better utilized by wheat than that applied at sowing in mid-November. A combination of the organic matter and urea was better than their application separately. N, P and K removal by the wheat crop was significantly increased by FYM and urea application. The time of their application influenced the nutrient removal by the crop in the same way as it affected its growth and yield.
Evaluation of amounts, methods and sources of zinc application to wheat in flood plain soils
Authors: Sharma B. D. , Katyal J. C.
Published: March 2009

Field experiments were conducted in a zinc-deficient flood plain alluvial soil to study the effect of amounts, methods and sources of zinc application on the yield and uptake of zinc by wheat. Zinc was applied at 0, 5 and 10 kg Zn/ha as zinc sulphate and zinc oxide either broadcast and mixed in the soil or drilled below the seed. Spray application of zinc was also tested. Irrespective of the source, grain yield and zinc uptake significantly increased up to 10 kg Zn/ha. Soil-applied zinc was highly correlated with yield and zinc uptake in the two field experiments. Grain yield was also found to be significantly correlated with zinc content of grain (r = 0·78), straw (r = 0·72) and flag leaf (r = 0·66). When applied at the rate of 10 kg Zn/ha, broadcasting of zinc sulphate and drilling of ZnO below the seed were equally effective in increasing grain yield of wheat. Foliar spray of zinc sulphate was an effective emergency method, but in highly zinc-deficient soils it did not compare well with soil application of zinc.
Take-all distribution and soil type on Chalky Boulder Clay
Authors: Catt J. A. , Gutteridge R. J. , Slope D. B.
Published: March 2009

In 1980 a field of winter wheat at Little Raveley, Cambridgeshire (U.K.) suffered a bad attack of take-all, which was confined mainly to areas dominated by Ragdale series, one of five soil types on the field. Take-all and yield were assessed on experimental areas within the field in the three subsequent years (1981–3). On a strip 50 m wide, which was sown with wheat in each of these years, take-all was in decline and although slight differences in take-all occurred between some of the soil types, they had no effect on grain yield. Following a break crop of beans in 1981, the remainder of the field carried wheat in 1982 and 1983. Here take-all was generally less and yields generally greater in the area that suffered the 1980 attack, probably because it had developed a natural partial immunity to the disease. However, measurements of takeall in relation to soil characteristics on 1 m2 plots suggested that the disease was becoming more prevalent on soils that are less well drained in winter, are more deeply decalcified, and contain less extractable phosphorus or more exchangeable potassium.
Field measurements of grassland poaching
Authors: Davies Patricia A. , Armstrong A.
Published: March 2009

Poaching damage to a new grass ley was measured over a period of time using a surface profile meter. Individual profiles obtained on different drainage treatments in the ley showed little change over 3 years of measurements. Poaching could be denned visually as a depression greater than 4 cm depth on this site. Degree of poaching was adequately described by the standard deviation of the soil surface. Typically, standard deviations along a poached, undrained transect were twice those of an unpoached, drained one. In this experiment drainage with pipes alone at 12 m spacing controlled poaching as well as mole drainage at 2 m with pipes at 40 m spacing even though watertable levels were usually not lower than those of the undrained control.
Enhancement of okra (Hibiscus esculentus) seedling growth and emergence by heat stress conditions
Authors: Onwueme I. C.
Published: March 2009

Seeds of okra were sown in moist soil and subjected to heat stress of 45 °C for 10 h on day 0 (day of sowing), day 1 or day 2 after sowing. Stresses on day 0 and, to a lesser extent, on day 1 promoted hypocotyl elongation and accelerated seedling emergence. Stress on day 2 retarded hypocotyl elongation and did not accelerate emergence. The results were similar for seeds sown at depths of 1, 4 or 7·5 cm. For 10-h stresses on day 0, 40 °C was slightly less promotive than 45 °C; but 50 °C or above resulted in no emergence whatsoever. Subjecting dry seeds to 40–60 °C for 24 h before sowing gave no appreciable acceleration of emergence; instead, at 60 °C there was a 24-h delay in the onset of emergence. Seeds were also incubated for 1·5 h in water at temperatures ranging from 40 to 80 °C. Emergence was accelerated at 40 to 65 °C, with the greatest acceleration at 45 °C. It is suggested that incubating the seeds at 45 °C for 1·5 h before sowing could afford a practical means to accelerate field emergence of okra.
Some observations on metabolite production and utilizationin vivoby the gut and liver of adult dairy cows
Authors: Baird G. D. , Symonds H. W. , Ash R.
Published: March 2009

Metabolite production rates were determined in the portal vein and hepatic veins of catheterized adult dairy cows maintained under normal conditions of husbandry. The production rates were calculated from the metabolite concentrations in arterial, portal and hepatic-venous blood, and from the rates of blood flow in the portal vein and the hepatic veins. In general, qualitatively similar metabolite production was observed in three non-lactating and two lactating cows, but production rates tended to be higher in the lactating cows due to higher blood flow rates.

About half the lactate utilized by the liver was absorbed from the gut, while the other half was derived from endogenous sources. Lactate absorbed from the gut was quantitatively of less significance than propionate as a substrate for hepatic metabolism. Even in cows that were well fed, there was a net production of ketone bodies from the liver that was almost as great as the net production from the gut. However, while the liver produced D-3-hydroxybutyrate it took up acetoacetate. In the lactating cows, acetate, propionate and butyrate were absorbed from the gut in the proportions of 9·5:2·5:1, respectively. About 90% and 80% of the absorbed propionate and butyrate, respectively, were taken up by the liver.

On the routine hay/concentrate diet there was little net uptake or output of glucose by the gut. However, there was consistent production of glucose by the liver, amounting to a maximum, in this study, of about 11 mol/24 h, assuming constant glucose production throughout the 24 h day. The rate of carbon dioxide appearance in the portal vein was about twice that of oxygen uptake by the gut. The liver used oxygen, and produced carbon dioxide, at nearly equal rates. The uptake of glucogenic substrates by the liver accounted adequately for the observed rates of hepatic gluconeogenesis.

In one of the lactating cows it was observed that there was a net production of acetate by the liver that amounted to half the net absorption of acetate from the gut (ethyl alcohol was not the precursor of this acetate) and that (glutamine + asparagine) and serine had the highest rates of appearance in the portal vein and the highest rates of uptake by the liver.
The effect of thermal and mechanical treatment on the drying rates of leaves and flowering stem internodes of Italian ryegrass (Lolium multiflorum) measured in the laboratory
Authors: Harris C. E. , Thaine R.
Published: March 2009

The drying rate of leaves and stem internodes from flowering culms of two varieties of Italian ryegrass (Lolium multiflorum) were measured in the laboratory in controlled conditions of temperature (28 °C), relative humidity (22%) and air speed (40 cm/sec), without treatment, or after being subjected to thermal treatment or to mechanical damage followed by thermal treatment. The two treatments increased the drying rate of leaves and, to a greater extent, stem internodes.

While it cannot be concluded that all treatments that increase crop drying rate will increase the rate for stems more than for leaves, these results are considered to indicate the possibility of devising practical treatments which will. Such treatments could reduce leaf shatter and consequent serious loss of dry matter during the field drying of grass crops.
Estimation of food intake of sheep grazing green pasture when no free water is available
Authors: Benjamin R. W. , Degen A. A. , Breighet A. , Chen M. , Tadmor N. H.
Published: March 2009

Two experiments were made to measure the dry-matter intake of grazing sheep. Three groups of five ewes grazed three plots of young barley. The mean daily drymatter intake per ewe from each group was estimated from the water turnover which was measured by the tritium dilution technique. The mean intake was also estimated by the double sampling technique for measuring standing crops. The mean estimate of one technique was within the standard deviation of the mean estimate of the other. The difference between the mean estimates from each technique did not exceed 18 %. It is concluded that water turnover could be useful for the measurement of the intakes of animals grazing green pastures.
Effect of protein concentration in the diet on blood composition and productivity of lactating Holstein cows under thermal stress
Authors: Hassan A. , Roussel J. D.
Published: March 2009

An experiment was designed to assess the effect of thermal stress and protein value of the diet on the productivity and some of the blood organic constituents of lactating Holstein cows. Two groups of eight animals each were used in 2 × 2 Latin-square designs with two experimental diets. The percentage of crude protein in the diets was 14.3 and 20.8 %.

Rectal temperature and respiration rate were recorded twice weekly and jugular blood samples were collected at weekly intervals for analysis. Daily feed intake, refusals and milk production per cow were recorded. Representative samples of morning and afternoon milk were taken three times a week for chemical analysis.

Data on respiration rate and rectal temperature suggested that both groups of animals were under thermal stress. However, significantly lower values were found by increasing the protein level of the diet. The higher level of protein significantly increased total milk production, 4 % fat-corrected milk (4 % FCM), total solids, solidsnot-fat, protein percentage and yield, casein and non-protein-nitrogen in milk. The increase in milk production and 4 % FCM was found to be associated with the increase in total feed and total-digestible-nutrients intake but not with crude-protein intake. Protein levels in the diet had no effect on fat percentage and yield nor on whey protein.

The correlation coefficients between respiration rate and rectal temperature with some of the blood organic constituents suggested an inverse relation between thermal stress and the blood organic constituents. The higher level of protein in the diet significantly increased haemoglobin levels but had no effect on oxyhaemoglobin, haemoglobin:oxyhaemoglobin ratio and haematocrit value. Total serum protein was not affected by thermal stress or by the protein value of the diet. Increasing protein levels in the diet increased albumin but decreased the globulin fraction of serum protein. Plasma glucose and non-protein nitrogen were increased by increasing the protein in the diet.
Effects of light and temperature on nodulation of cowpea and hyacinth bean
Authors: Mahdi A. A. , Habish H. A.
Published: March 2009

Cowpea and hyacinth bean nodulated and grew well at 11–14 h and poorly at 8 h light duration. Nodulation and plant growth increased with increase in light intensity from 1·4 to 17·1 W/m2 but the natural light intensity (228·3 W/m2) inhibited nodulation in July and plant growth in December.

Nodulation and growth of both crops were best at ‘moderate’ temperature and cowpea tolerated ‘warm’ more than ‘cool’ temperatures whereas hyacinth bean showed the reverse situation.

Inoculation improved nodulation of cowpea but not hyacinth bean. Application of nitrogen did not improve the growth of plants affected by light and temperature.
Results from two experiments with winter wheat, comparing top-dressings of a liquid N-fertilizer either alone or with added herbicide or mildew fungicide or both, and of ‘Nitro-Chalk’ without or with the herbicide or fungicide or both
Authors: Penny A. , Jenkyn J. F.
Published: March 2009

Experiments with winter wheat in 1972 and 1973 tested all combinations of ‘Nitro-Chalk’ ν. liquid N-fertilizer, 56 ν. 112 kg N/ha, 0 ν 5·6 1/ha of herbicide (2·8 kg acid equivalent/ha) and 0 ν 0·7 1/ha of mildew fungicide, all applied at growth stage 4–5 of the Feekes scale. The liquid fertilizer (26 % N) was a solution of ammonium nitrate and urea, the herbicide was a mixture of dichlorprop and MCPA and the mildew fungicide contained 75 % (w/v) of the active ingredient tridemorph.

The herbicide and mildew fungicide were sprayed either alone or together and neither scorched the wheat leaves. Liquid N-fertilizer by itself slightly scorched the wheat leaves and scorch was increased by adding herbicide to it, but more by adding the fungicide and most by adding both; it was then severe, especially with 112 kg N/ha.

Weed control after adding herbicide to the liquid fertilizer was at least as good as from herbicide sprayed alone.

In July, foliar diseases were much more severe with 112 than with 56 kg N/ha, but effects of the other treatments, including fungicide, on foliar diseases, were then very small.

With 56 kg N/ha, yields were slightly larger with ‘Nitro-Chalk’ alone than with the liquid N-fertilizer alone, but with 112 kg N/ha they were slightly larger with the liquid fertilizer; adding herbicide to the liquid fertilizer did not change these results. With either amount of N, adding mildew fungicide to the liquid fertilizer made it less good than ‘Nitro-Chalk’, presumably because of the damage from leaf scorch; adding both herbicide and fungicide to the liquid fertilizer increased the damage.
A note on Griffing's models for the diallel cross
Authors: Thompson B. K.
Published: March 2009

Some misconceptions concerning the application of Griffing's fixed effects model I and mixed effects model B are discussed.
Trials with monogerm seed for the mechanization of spring work in sugar beet
Authors: Hanbury L. F. , Mughan G. L.
Published: March 2009

Since sugar beet was first grown on farms it has been difficult to establish single seedlings at the required spacing because each seed unit was liable to produce a cluster of seedlings. Plant breeders have introduced varieties with monogerm seed and these were used between 1960 and 1962 to see if they led to any savings in labour with hand and machine thinning and to determine the yields of beet after these treatments. The trials described show that, after machine thinning, predetermined final plant populations with 90% of single seedlings were obtained and, when a herbicide was effective in weed control, the labour requirement was about 5% of that required to hand single a crop from multigerm seed. When singled by hand the monogerm varieties required 90 % of the labour needed to single a multigerm crop but the mean yield per acre of the monogerm varieties used was at least six tons per acre less than that from a commercial variety with multigerm seed.
Studies of the metabolism of cattle given high concentrate diets
Authors: Topps J. H. , Reed W. D. C. , Elliott R. C.
Published: March 2009

1. Four mature, fistulated Africander steers were used to study the effect of four different high concentrate diets on the concentration and rate of production of steam V.F.A., and on concentrations of certain constituents found in the blood, rumen digesta and urine of these animals. Each steer received each diet for 4 weeks in a Latin square design and samples of blood, rumen digesta and urine wore taken in the last week of each monthly period. The diets were based on maize grain with a protein-mineral-vitamin A supplement and contained varying proportions of roughage, namely, 0, 10, 20 and 30% of the quantity of concentrate.
Birthcoat–adult fleece relationship: a study of kemp succession in a coarse wool breed of sheep
Authors: Guirgis R. A. , El Gabbas H. M. H. , Galal E. S. E. , Ghoneim K. E.
Published: March 2009

The birthcoat of coarse wool Barki lambs was investigated at the age of 1–1·5 months. Lambs were covered when they were 2 months old to study kemp succession, and some other adult fleece traits, at the age of 16 months in relation to the birthcoat fibre type arrays. Samples were taken from three dorsal and three lateral positions. The average halo hair grade was 5·45% and the coarse fibre type array, plateau, contributed 64·7% of the birthcoat arrays, the rest were of the less coarse, saddle, type. Halo hair grade and fibre type arrays showed an antero-posterior gradient, increasing in score and coarseness posteriorly.

All halo hairs, 41·9% of super sickles and 22·6% of hairy tip curly tip fibres were shed as first generation kemp (G1 Curly tip and histerotrich fibres shed the least and they contributed the majority of the total persistent fibres. When pre-curly tip fibres increased in the birthcoat samples, that was followed by more kemp in the adult fleece.

The average G1% kemp was 4·43. Kemp decreased in subsequent generations, values were 34·50 and 8·37 for G2/G1% and G1/%, respectively. G1%, and G2/G1% kemp showed a general trend of an increase towards posterior positions; the shoulder position was an exception to that.

Coarse birthcoat fibre type arrays, plateau, were followed by more kemp in G1% and in successive generations than were the less coarse, saddle, arrays. High values of G2/G1% kemp were followed by significantly high G3/G1% kemp. Within animals, there was a significant correlation (P < 0·01) between halo hair grade and G1% kemp.

Staple length showed a tendency to increase towards posterior positions and females showed slightly longer staples than those of males. A slight trend of decrease in staple length was observed following the less coarse array, saddle, as compared with that which followed the coarse array, plateau.

For selection against kemp at an early stage, though birthcoat halo hair grade was positively correlated with G1% kemp, a high halo hair grade is essential for the lamb's early survival, hence fibre type arrays should be considered in selection. Less coarse birthcoat arrays, saddle in the present material, and a high, within array, curly tip: pre-curly tip ratio would be preferrable.
The development of plant components and their effects on the composition of fresh and ensiled forage maize: 2. The effect of genotype, plant density and date of harvest on the composition of maize silage
Authors: Wilkinson J. M. , Phipps R. H.
Published: March 2009

Forage maize was harvested on three occasions from three genotypes (Inra 200, LG11 and Anjou 210), grown at three plant densities (5·0, 9·8 and 13·5 plants/m2). Three replicate silos were filled with 8 kg fresh crop per treatment, sealed, and stored for 100 days.

Crops from all treatments fermented to give predominantly lactic acid, low values for pH (average 3·9, range 3·7–4·1), with no butyric acid. Apparent loss of watersoluble carbohydrates during storage appeared to be directly related to their content at harvest.

Genotype and plant density had relatively little effect on the composition of the silage, or on digestibility in vitro. Later harvest was reflected in increased contents of dry matter and starch, and in restricted fermentation. The content of digestible organic matter in the D.M. was decreased by later harvest.
The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage
Authors: Ørskov E. R. , McDonald I.
Published: March 2009

A method is proposed for estimating the percentage of dietary protein that is degraded by microbial action in the rumen when protein supplement is added to a specified ration. The potential degradability, p, is measured by incubating the supplement in artificial-fibre bags in the rumen and is related to incubation time, t, by the equation p = a+b(1 – e-ct). The rate constant k, measuring the passage of the supplement from the rumen to the abomasum, is obtained in a separate experiment in which the supplement is combined with a chromium marker which renders it completely indigestible. The effective percentage degradation, p, of the supplement, allowing for rate of passage, is shown to be p = a+[bc/(c+k)] (1-e-(e+k)t) by time, t, after feeding. As t increases, this tends to the asymptotic value a+bc/(c+k), which therefore provides an estimate of the degradability of the protein supplement under the specified feeding conditions.

The method is illustrated by results obtained with soya-bean meal fed as a supplement to a dried-grass diet for sheep. The incubation measurements showed that 89% of the soya-bean protein disappeared within 24 h and indicated that it was all ultimately degradable with this diet.

When the dried grass was given at a restricted level of feeding the allowance for time of retention in the rumen reduced the estimate of final degradability to 71% (69% within 24 h). With ad libitum feeding there was a faster rate of passage and the final degradability was estimated to be 66% (65% within 24 h).
Inherited physiological differences in red cell characteristics of Welsh mountain sheep
Authors: Khattab A. G. H. , Watson J. H. , Axford R. F. E.
Published: March 2009

1. Evidence is given of an association between the two loci governing inheritance of haemoglobin type and erythrocyte potassium concentration in Welsh Mountain sheep.

2. In the 1777 animals examined, there was an excess of high potassium types amongst carriers of the haemoglobin B gene.

3. At both high and low levels of potassium, sheep possessing haemoglobin A only had significantly more potassium in their blood than animals possessing haemoglobin B only. AB heterozygotes were intermediate in. value.
The effect of haemoglobin and potassium polymorphism on growth and wool production in Welsh mountain sheep
Authors: Watson J. H. , Khattab A. G. H.
Published: March 2009

A population of 1549 Welsh Mountain sheep, typed for haemoglobin and blood potassium concentration, were examined for correlations with production traits.

The statistical analysis was carried out within years, to avoid seasonal effects, and constants were fitted for sire, parity of birth and sex, as well as for haemoglobin and potassium type.

Few of the associations dependent on haemoglobin and potassium level reached significance at generally accepted levels of probability but an underlying consistency existed in mean values. Generally, animals of LK phenotypes showed marginally better neo-natal growth than HK phenotypes and animals possessing haemoglobin A had greater fleece-weights than those which did not.
The effcts of fertilizers on herbage production. II. The effect of nitrogen, phosphorus and potassium on botanical and chemical composition
Authors: Reith J. W. S. , Inkson R. H. E. , Holmes W. , Maclusky D. S. , Reid D. , Heddle R. G. , Copeman G. J. F.
Published: March 2009

Six factorial experiments, each lasting 3 years, were carried out to determine the effects of N, P and K on herbage cut five times each year.

Clover almost disappeared with the 87 lb. N treatment and none survived with the 174and 348 lb. dressings. N increased the proportions of rye-grass and cocksfoot in the sward. P had no influence on botanical composition. K usually increased the clover content in the absence of, but had practically no effect in the presence of, N.
The growth of the swede crop in relation to seed size
Authors: Lang R. W. , Holmes J. C.
Published: March 2009

1. The effects of seed size in the swede crop on germination, emergence, growth and final yield were studied during the period 1959 to 1962.

2. The germination percentage was similar for all sizes of seed, but the emergence percentage was slightly poorer for ‘large’ and ‘small’ seed than for ‘graded’ seed.

3. Leaf area in the early stages of growth was proportional to the seed size, but as the season advanced the plants from small seed grew at a relatively faster rate than those from large seed, so that at harvest the relative yield difference, although still in favour of large seed, was much smaller than the relative difference in seed weight or seedling leaf area. It was shown that the relatively faster growth rate from small seed was not due to a later onset of inter-plant competition.
Effect of light intensity on assimilation characteristics of detached tea leaves
Authors: Barua D. N.
Published: March 2009

Photosynthetic rates of detached, mature tea leaves from four different sources were determined in excess CO2 and light of 4, 10, 16 and 32 klux intensities from a tungsten-filament lamp. Temperature was maintained at 25°C. The assimilation rates were significantly different for the four sources both in weak and in strong light. Neither thickness of the leaf lamina nor chlorophyll concentration could explain the cause of this difference.

The effect of shade adaptation on the subsequent rate of assimilation was examined in one of the four sources of leaf. Shade-adapted leaves had significantly higher rates of photosynthesis at the weakest light intensity of 4 klux and lower rates in 16 and 32 klux intensities than the corresponding sun leaves.
Investigations into copper deficiency in crops in East Anglia
Authors: Pizer N. H. , Caldwell T. H. , Burgess G. R. , Jones J. L. O.
Published: March 2009

1. An account is given of the occurrence of copper deficiency in crops grown on the Fenland peats and glacial sands of East Anglia. Copper deficiency in the crops appears to be due to actual deficiency of available copper in the peat and sandy soils. The level of copper extracted from soils by an acid solution (pH 4.0) of the ammonium salt of E.D.T.A. provides a useful indication of soils deficient in copper, though the occurrence of the deficiency and its severity in crops is influenced by other soil factors, level of water-table in peats, species of crop and weather during the growing season.

2. Of the crops grown on the peat and sandy soils of East Anglia the most susceptible to copper deficiency are cereals. Visual symptoms of deficiency are described as these provide an important aid in diagnosis.
Effects of irrigation and benomyl treatment on chocolate spot (Botrytis fabae) and yield of winter-sown field beans (Vicia faba)
Authors: Fitt B. D. L. , Finney M. E. , Creighton N. F.
Published: March 2009

In 1976–7, 1977–8 and 1978–9 plots of winter-sown field beans, either irrigated in June and July or unirrigated, were treated with one or more sprays of benomyl or were untreated. The amounts of chocolate spot on field bean leaves and flowers were increased by irrigation and decreased by benomyl in all seasons. These effects were greater in 1977 and 1978, when there was respectively 76·5 and 82·4 mm rainfall in June, than in 1979, when there was 30 mm rainfall in June and less chocolate spot developed. Leaves half-way up stems of plants in irrigated, unsprayed plots had 11% of their area affected in July 1977, 17% affected in July 1978, but only 4% affected in August 1979. By contrast, middle leaves of plants in unirrigated, sprayed plots had 3, 4 and 0·3% of their leaves affected in 1977, 1978 and 1979 respectively. Irrigation increased the number of pods per stem in 1977 and 1979 and decreased it in 1978; it decreased grain yield in 1977 and 1978, but increased yield in 1979. Benomyl treatments affected the number of pods little in any year; they increased yield in 1977 and and 1978, but not in 1979.
Seed vigour in cultivars of dwarf French bean (Phaseolus vulgaris) in relation to the colour of the testa
Authors: Powell Alison A. , Oliveira M. De A. , Matthews S.
Published: March 2009

Differences in the field emergence of 30 commercial seed lots of dwarf French beans were associated with the colour of the testa, the 11 lots with a white testa having a lower mean field emergence of 67% compared with 91% for lots with black (11 lots) or brown (8 lots) testae. The white-seeded lots also had higher leachate conductivities (mean 42 μ S/cm/g) and imbibed more rapidly (an average 43% weight increase after 6 h imbibition) than black- or brown-seeded lots (average 25 μS/cm/g; 30% weight increase). The extent of damage to the testa which was slight in all lots was not related to differences in either the field emergence or rate of imbibition of the lots. In two successive imbibition cycles seeds of Provider (brown testae) took up water far more rapidly in the second imbibition (78% weight increase after 3 h) than the first (25% weight increase). The coloured testae normally adhere very tightly to the cotyledons but were loosened following the first imbibition leading to a more rapid uptake of water. The rapid imbibition of Tenderette (white testae) which has a loose fitting testa even in the dry seed was increased only slightly by a second imbibition. When seeds were imbibed from one end only from which the testa was removed Tenderette imbibed rapidly (90% weight increase after 12 h) whereas in Provider the tightly adhering testa limited the rate of water uptake (42% weight increase after 12 h) despite the ready access of water to the seed. It is suggested that the degree of adherence of the testa to the cotyledons is the major factor influencing the rate of imbibition of cultivars of dwarf French beans differing in testa colour and its role in determining seed vigour is discussed.
The utilization of the metabolizable energy of diets of different protein content by the milk-fed lamb
Authors: Walker D. M. , Norton B. W.
Published: March 2009

Nineteen male cross-bred lambs, aged between 2 and 5 days, were allotted to each of three dietary treatments for an experimental period of 3 weeks. The protein contents of the diets (on a dry-matter basis) were 12·0% (diet A), 28·5% (diet B) and 45·5% (diet C). The diets were fed as artificial milks that contained 15% total solids, and the energy intakes of groups of lambs within each dietary treatment varied from below maintenance to ad lib.

Metabolizable energy (ME) as a percentage of the gross energy was constant for all diets, at all levels of energy intake, at 94·3 ± 0·3%. ME intake was linearly related to energy retention above maintenance with all diets. There was a significant linear decrease in the net efficiency of ME utilization as the protein content of the diet increased. However, the individual regressions did not differ significantly from the common regression coefficient of 0·686 ± 0·018, i.e. a net efficiency of 68·6 ± 1·8%. The individual coefficients were 0·740, 0·679 and 0·634 for diets A, B and C respectively.

The ME requirement for energy equilibrium (maintenance) of lambs given diet B (100·4± 11·7 kcal/kg0·73 day) was significantly lower than that of lambs given diet A (126·4 ± 14·3) or diet C (119·2 ± 15·6). The energy costs of fat and protein deposition, calculated by multiple regression analysis of the pooled data, were 11·1 kcal ME per g fat and 8·5 kcal ME per g protein respectively.
The effect of plant population and CCC on Spring wheat varieties with and without a dwarfing gene
Authors: Lovett J. V. , Kirby E. J. M.
Published: March 2009

The growth and development of the spring wheat varieties Kolibri, Sirius and TB 435 ranging in height from relatively tall to semi-dwarf were compared when sown at 50, 200 and 800 plants m−2, with and without a spray application of CCC at the six-leaf stage. Growth analysis measurements were made throughout the season. Yield and yield components were determined at final harvest.

A number of varieties x density and variety x CCC interactions were found which support the hypothesis that genotypic variation and environmentally induced differences in GA metabolism affect the agronomic performance of the crop.
Investigations into the mode of action of farmyard manure. I. The influence of soil moisture conditions on the response of maincrop potatoes to farmyard manure
Authors: Holliday R. , Harris P. M. , Baba M. R.
Published: March 2009

1. The paper describes ten consecutive field experiments carried out between 1952 and 1961 investigating the action of F.Y.M. on the yield of maincrop potatoes. In all experiments high basal dressings of PK fertilizer were used.

2. Soil moisture deficits were estimated from meteorological data and the maximum deficit (M.S.M.D.) in a particular season used as an index of the dryness of the growing season.
The effect of varying the date of application of fertilizer nitrogen on the yield and seasonal productivity of grassland
Authors: Castle M. E. , Reid D. , Heddle R. G.
Published: March 2009

1. Two identical small plot experiments were done from 1961 to 1963, at the Hannah Dairy Research Institute, Ayr and at Boghall Farm, Midlothian to study the effects of applying nitrogen fertilizer at different times on total yield and its seasonal distribution.

2. Two perennial rye-grass plus white clover swards, one containing S23 and the other S24, were used at each site. On both swards a total of 10 cwt. of ‘Nitro-Chalk’ (15·5% N)/acre, applied at varying dates over the growing season, and a control treatment which received no nitrogen fertilizer were tested.
The association between depot fat mobilization and the presence of xanthophyll in the plasma of normal sheep
Authors: Patterson D. S. P.
Published: March 2009

1. Blood plasma of normal fed sheep is not pigmented but on starvation the plasma assumes a yellow to green colour. Unlike the pigments of the so-called yellow fatted sheep, the pigmentation disappears on refeeding.

2. Using spectrophotometric and chromatographic methods, this pigment has been identified as xanthophyll (lutein).

3. The xanthophyll content of plasma is related to the plasma non-esterified fatty acid (N.E.F.A.) concentration and it therefore appears that the pigment is mobilized from the fat depots together with the free fatty acids. Maximum levels of about 60μg./100 ml. xanthophyll are observed in sheep plasma after 4 days starvation.
Ovulation rate in ewes treated with pregnant mares' serum gonadotrophin and luteinizing hormone releasing factor
Authors: McGovern P. T. , Laing J. A.
Published: March 2009

Although the administration of pregnant mares' serum gonadotrophin (PMSG) to induce superovulation is a well established procedure (see Anderson, Schultz & Melampny, 1963), the unpredictability of the response to this treatment continues to impose a constraint on the commercial application of egg transfer techniques in the large domestic animals. In sheep, the additional use of human chorionic gonadotrophin (HCG) has been mainly centred on attempts to control the time of ovulation (Ortavant, Thibault & Wintenberger, 1949; Braden, Lamond & Radford, 1960; Dziuk et al. 1964; McGovern, Williams & Hancock, 1969). However, Killeen & Moore (1970) found that the proportion of follicles which rupture was increased in PMSG-treated ewes which had been given HCG at the beginning of oestrus. The purpose of the observations recorded here was to examine the possibility that a further gain in ovulation rate in PMSG-treated sheep might be obtained with the use of luteinizing hormone releasing factor (LHRF). No attempt was made to reproduce physiological levels of the releasing factor and dosage was aimed at achieving a superovulatory effect.
Effects of intraperitoneal injections of DL-methionine on the voluntary intake and wool growth of sheep fed sole diets of hay, silage and pasture differing in digestibility
Authors: Barry T. N.
Published: March 2009

Penned Romney wether sheep were fed ad libitum diets of untreated silage and hay made from the same pasture (Expt 1), untreated silage (Expt 2), and high quality fresh pasture (Expt 3). Voluntary intake and wool growth were measured. In each experiment half of the sheep were given intraperitoneal injections three times per week which supplied the equivalent of 1·03 g DL-methionine/day.

Relative to silage in Expt 1, hay increased voluntary dry matter intake, depressed apparent nitrogen digestibility and increased wool growth. Methionine supplementation increased voluntary intake and wool growth with animals fed on hay or silage in Expt 1 and with those fed on silage in Expt 2, but had no effect on either variate with the diet of fresh pasture.

Wool sulphur content, measured in Expts 2 and 3, was increased by methionine supplementation, and it was calculated that 34 and 15% respectively of the sulphur administered as methionine was recovered in the wool.

The effects produced by methionine supplementation in this work are compared with those produced from different forms of post-ruminal amino acid supplementation in sheep fed a variety of diets. Factorial estimates of the requirements for sulphur of sheep and cattle in different physiological states have been calculated, and are discussed in relation to results of trials involving supplementation with sulphur-containing amino acids.
Differences in the concentrations of certain blood constituents among cows in a dairy herd
Authors: Kitchenham Barbara A. , Rowlands G. J.
Published: March 2009

Blood samples were taken on six occasions from a herd of 172 Friesian, Ayrshire and Friesian × Ayrshire dairy cows, and analysed for packed cell volume, blood glucose, haemoglobin and serum albumin, total protein, urea nitrogen, inorganic phosphate, Ca, Mg, K and Na. Differences in blood composition among cows, adjusted for differences in stage of lactation, were demonstrated for all blood constituents (P < 0·001) with the variation among cows proportionally largest for globulin and total protein and smallest for Na. Correlations between blood constituents were for the most part small.

Globulin and total protein concentrations increased with age (P < 0·001) and concentrations of inorganic phosphate, albumin, Mg, Na and urea decreased with increasing age (P < 0·001 for inorganic phosphate and Mg, P < 0·01 for albumin, Na and urea). Frequency distributions of the concentrations of the blood constituents adjusted for age and breed showed significant deviations from normality for globulin (P < 0·05) and Hb (P < 0·01).

There were significant relationships between the concentrations of globulin and total protein of 43 dams and their daughters (P < 0·01 for globulin, P < 0·05 for total protein). There were also significant differences in groups of daughters of different sires for concentrations of urea, globulin, total protein, albumin, Mg, Ca, K and PCV (P < 0·01 for urea and globulin, P < 0·05 for the other constituents).
Effects of cold treatments on the sprout growth of three potato varieties
Authors: Wurr D. C. E. , Allen E. J.
Published: March 2009

A period of storage at 2–3 °C followed by storage at higher temperatures more suitable for sprouting, gave a more rapid and greater total sprout development than that produced by continuous storage in sprouting conditions. The effect on the number of sprouts produced and the potential yield advantages to be gained from increasing sprout development by such a treatment are discussed.