bluuebunny/crossref_metadata_2025 huggingface dataset:
The character of barley grown on soil made acid with sulphate of ammonia
Authors: Mann Harold H.
Published: March 2009

The effect of sulphate of ammonia in tending to make soil acid when it is applied as a manure has been well known ever since about 1891 when Wheeler (1) first observed the phenomenon at the Rhode Island Experiment Station. Similar results to those observed by Wheeler have been found all over the world where this manure has been applied for many years on soils containing very little calcium carbonate. One of these cases has occurred at the Woburn Experimental Station, where acidity has developed which has been fatal to continued cultivation of both wheat and barley. Seeing that the soil in the continuous barley experiments at this station has been treated with sulphate of ammonia for fifty years, with or without other mineral manures, the conditions have given an excellent opportunity to study the effect of soils made acid in this way on the growth and composition of the barley plant.
A study of the development of the characters of the fleece during growth in the different regions of the body
Authors: Thomasset L. F.
Published: March 2009

1. A study has been made of the relative development of some regions in the fleece of twin lambs of a Suffolk ♂ × Suffolk (Border Leicester-Cheviot) ♀ cross during growth. The different regions develop in the following order: shoulder → leg → belly → tail. It is concluded that an improved animal is one in which the latest developing part of the fleece has the least possible number of undesirable fibres at the earliest possible age. The breeds of sheep begin their wool improvement by changes in the earliest developing regions (shoulder) and finish it in the latest (tail).

2. The properties of the fleece studied were the colour of the fibres, the medullated fibres, the fineness of the fibres, and uniformity of fibre size. In general a relationship is found between the stage and rapidity of development of the area, and the properties of the fibre. The intensity of the colour is stronger during the early active stages of development. There is a tendency to lose some kinds of coloured fibres, and to diminish the intensity of the colour in others as the development of each region in which the fibres grow proceeds.

The medullated fibres appeared in greatest quantities in the later developing regions, except the belly which presents few medullated fibres.

The staple is much finer at the first month of growth than in the later stages. Frequency curves of fibre size are of more value than average fibre size in estimating the value of the fleece.

3. It is suggested that the examination of the fleece of the lamb will give some idea of its genetic constitution and will reveal defects which would be concealed in the adult. Such a “phaeno-genetic” selection can be made best in a “late developing” area of the body such as the tail of the lamb at one month old.
The measurement of pF in soil by freezing-point
Authors: Schofield R. K. , da Costa J. V. Botelho
Published: March 2009

Two procedures are described for ascertaining the relationship between the freezing-point and moisture content of a soil. Since the soil sample is dried in the process of freezing, it is necessary to estimate how much water has been frozen out of the soil at the moment when the freezing temperature is recorded.

Procedure A embodies all the precautions which appear desirable when the greatest accuracy is required. Procedure B is simple and rapid and yet accurate enough for routine estimations.
Identification and measurement of the combustible gases that occur in the gaseous metabolic products of sheep
Authors: Lugg Joseph W. H.
Published: March 2009

Measurementsof the gaseous metabolism of sheep in this laboratory are conducted by drawing air through a sealed chamber that contains the animal, sampling the effluent air, and analysing the sample for its carbon dioxide increase and its oxygen deficit. As the analysis is dependent upon the measured fraction of nitrogen with rare gases, and particularly in respect of the oxygen deficiency this fraction must be known rather precisely. It is of course assumed that the animal in no way changes the quantities of nitrogen and rare gases passing through the chamber, but the analysis is incomplete if any gases or vapours other than carbon dioxide and water are given off.

It is well known that considerable quantities of methane, and possibly some hydrogen, are produced by ruminants, and some forms of gas analysis apparatus include a device designed to measure the concentration of methane in the sample. The device, as used in the apparatus of Carpenter & Fox (1926), consists of a platinum spiral heated electrically, the carbon dioxide resulting from combustion being measured volumetrically in the ordinary way, together with the O2consumed. Experience with the device in this laboratory has led to its abandonment and gravimetric methods are now employed instead.
Observations on the effects of temperature and distance to water on the behaviour of Merino and Border Leicester sheep
Authors: Daws G. T. , Squires V. R.
Published: March 2009

The effects of ambient temperature on the daily behaviour patterns and water consumption of Border Leicester and Merino wethers were examined in an experiment where food was supplied ad libitum at points ranging from 2·4 to 5·6 km from water. The data were collected during a 12-week period when daily maximum temperatures ranged from 24 °C to 45 °C.

At distances where twice-daily drinking appeared normal and maximum air temperatures exceeded 38 °C, Merinos abandoned the afternoon walk to water, and the Border Leicesters either abandoned the walk or reduced consumption. However, until the temperature reached 38 °C water intakes of both breeds were positively related to temperature. Border Leicesters increased consumption at a mean rate of 0·42 ± 0·072 l/head/°C until maximum ambient temperatures approached 38 °C, compared with the Merino rate of 0–17 ± 0·054 l/head/°C.

Border Leicesters responded to temperature by drinking earlier in the mornings as minimum overnight temperatures rose, and by increased night activity when mean night temperatures exceeded 25 °C. Merinos showed no such response.
Allometric growth of the forelimb in cattle
Authors: Pontecorvo Guido
Published: March 2009

Analysing Hammond's data on the growth of limbs in the sheep, Huxley (1932) found a post-natal simple negative heterogony, or allometry, as in the latest terminology (Teissier, 1937), of the whole limb relative to the body. As lambs, and the young of most other grazing mammals, are born with relatively long limbs enabling them to follow their dams (Hammond, 1932), the same author pointed out that the leg must have exhibited positive allometry during foetal development.

Having possession of a sufficient body of measurements on the skeletal development of female calves of the Chianina breed, a very tall beef and draft breed of cattle of Central Italy, I investigated the course of growth of height at withers relative to the growth of the length of the trunk (from shoulder to ischium). The growth of height at withers can be considered as a sufficiently reliable measure of the growth of forelimb length owing to the fact that the two principal angles in the limb (scapula-humerus and humerus-radius) do not change very much with age (Engeler, 1935).

It was found that the growth of forelimb length in this breed of cattle exhibits a simple negative allometry relative to the growth of trunk length. This simple allometry, with growth constant about 0·78, holds from birth until over the age of 3 years, that is, throughout practically the whole post-natal growth.

Lack of data after this age leaves open to further research the course in the ultimate period of development.

I thought it would be of some interest to compare various breeds of cattle differing rather widely in the absolute values, as well as in the proportions of height at withers and trunk length at birth and in later life.
A study of the fasting metabolism of various breeds of hog: III. Metabolism and surface area measurements.
Authors: Deighton Thomas
Published: March 2009

From metabolism experiments carried out on the pigs enumerated in the first paper of this series the following conclusions are drawn:

(a) The metabolism in a state of inanition appears to be more a function of a power of the weight than of the true surface area as determined by the photographic method.

(b) Hogs born in the summer and autumn of one year appear to show two maxima of metabolism; one almost immediately, as has been observed previously, and another during the following summer, provisionally ascribed to the effect of light on thyroid activity, produced by the intermediary action of the anterior pituitary.

(c) Actual, and theoretically computed average growths are shown to agree remarkably well in the case of eleven of the pigs which were treated in an exactly similar manner. Individual growth curves showed no such agreement. This is considered to strengthen the evidence for the writer's previously stated view that nett energy is a statistical rather than a physiological constant.
The body proportions of different breeds of bacon pigs
Authors: Hammond John , Murray G. N.
Published: March 2009

Weights and measurements of sides of bacon made under standard conditions from different breeds and crosses of pigs and exhibited at the London Dairy Show from 1922–31 have been analysed statistically.

1. The actual live weight of the pig affects the carcass percentage more than does breed or type.

2. For a bacon pig of 200 lb. live weight, there is an optimum carcass percentage (about 79 per cent) and an optimum bacon percentage (about 58 per cent). The highest percentage is not necessarily best, for below about this level the proportion of bone will be too large and above this level the proportion of fat will be too large.

3. The reasons why certain measurements and proportions are necessary to meet market requirements are detailed.

4. The changes in the proportions of the side with increase in weight of the side are described. The proportional increase in bacon weight is much greater than the proportional increase in side length. Both belly thickness and thickness of shoulder fat increase in their proportions at a faster rate than side length, but not so fast as side weight. The thickness of fat over the loin is the only part measured which increases at a faster rate than side weight.

5. The subcutaneous layer of fat matures earliest at the shoulder, over the rump next, and on the loin last. The rate of increase of the back fat slows down as the sides increase in weight. This slackening of growth is greatest in the shoulder and least in the loin, the rump area being intermediate.
The effect of Chlorpropham on the storage of swedes
Authors: McKelvie A. D. , Olorunda A. O. , Kay M.
Published: March 2009

The sprout inhibitor Chlorpropham (CIPC) [isopropyl N-(3 chlorophenyl) carbamate] was found to be an effective sprout inhibitor in stored swedes (Brassica napus L.) under certain conditions. It was ineffective and unnecessary in swedes stored from November to April but necessary for those stored in clamps from March to July. CIPC did not, however, prevent rotting nor arrest normal chemical changes. Rotting developed because of the restricted ventilation necessary for successful use of CIPC and was more severe in mechanically than in hand-harvested roots. The main advantage of using CIPC to extend the storage and feeding life of swedes is that the absence of sprouts makes the handling of the roots much easier.

Friesian bulls fed swedes preserved with CIPC and supplemented with 50% conconcentrates gave satisfactory growth compared with similar bulls offered a diet containing only barley.
Manuring of meadow-hay land. The effect of manures and lime on the botanical composition and yield of hay. (With two text-figures.)
Authors: Jacques W. A.
Published: March 2009

The object of these experiments was to compare the effect of dung, artificial manures and lime on yield and botanical composition of meadow hay.

The soil is a light loam derived from a coal measures sandstone, and is naturally sour. The poor type of herbage it produces is typical of a large acreage of land in the West Riding.

The northern halves of the plots were limed, and the results obtained show striking differences between the limed and unlimed halves which must be taken into account in any comparison made between the different manurial treatments.
The fatty-acid composition of tropical pastures
Authors: O'Kelly J. C. , Reich H. P.
Published: March 2009

There is an increasing interest in the effect of dietary lipids on the fatty-acid composition of animal tissue lipids, and long-chain fatty acids may make a substantial contribution to the nutritive value of the diet. A cow at pasture may ingest as much as 450 g of lipid in a day (Garton, 1960a) and a recent study reported the influence of pasturefeeding on the body-fat composition of horses (Bowland & Newell, 1974). Most of the data on the fatty-acid composition of pasture lipids are for clover-rich pastures and mixed pasture grasses grown in temperate climates (e.g. Garton, 1960b). By contrast, the lipid composition of tropical pastures has been neglected. This paper reports the seasonal changes in the lipid content and fatty-acid composition of eight species of tropical pasture plants.
Herbage characteristics of perennial ryegrass, cocksfoot, tall fescue and timothy pastures and their relationship with animal performance under upland conditions
Authors: Davies D. A. , Morgan T. E. H.
Published: March 2009

Herbage characteristics of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), tall fescue (Festuca arundinacea Schreb.) and timothy (Phleum pratense L.) pastures were obtained whilst rotationally grazed by ewes and their single lambs at a fixed stocking rate of 25/ha on an upland site (305 m O.D.) in mid-Wales. Drymatter production of cocksfoot averaged 32·1 kg/ha/day over the 3-year duration of the trial (1975·7) and was 13·3 kg/ha/day lower than that of the other three grass species. This resulted in a 8 kg/ha/day reduction in dry-matter intake on cocksfoot; this was significantly lower (P < 0·05) than that achieved on the other grasses, which were similar to one another around 36 kg/ha/day.

In vitro digestibility of the herbage ranked in the order perennial ryegrass > timothy = cocksfoot > tall fescue. Intake of digestible organic matter (DOMI) was lower on cocksfoot than on perennial ryegrass and timothy. Differences were also detected in crude protein, water-soluble carbohydrates and sodium composition between species.

Dry-matter intake was positively correlated with herbage growth rates (r = 0·95, P < 0·001) but not to digestibility of herbage on offer (r = 0·18). Both ewe and lamb live-weight gains were positively related to intake of dry matter and DOMI.

Reference is made to comparative yield data between the grasses obtained under cutting trials. In the 2nd and 3rd harvest years (1967–1967) growth rates in the grazing experiment were 76, 61, 81 and 80% of the 66·2, 66·7, 67·8 and 65·0 kg D.M./ha/day obtained under a cutting regime on perennial ryegrass, cocksfoot, tall fescue and timothy swards respectively. This illustrates the danger involved in assessing the potential of grasses based on such information.

The results are discussed in relation to the value of the species for use under grazing in the uplands.
The effect of winter and early spring grazing by sheep on subsequent sward production
Authors: Wilman D. , Griffiths P. D.
Published: March 2009

The effect on sward production of grazing by sheep during different periods of the winter and the effect of different dates of ceasing grazing in late winter-early spring were measured in field experiments by cuts during the spring and summer and by botanical analysis.

Winter and early spring grazing reduced herbage yield in April, May and June, but not subsequently. Nitrogenous fertilizer applied when grazing ceased approximately counterbalanced the reduction in yield due to grazing. The grazing treatments had little or no effect on botanical composition. The size of the reduction in yield due to grazing was such that it might reasonably be explained in terms of the date on which grazing ceased and the amount of photosynthetic tissue left at that date. The amount of yield added during a given period in the spring appeared to be very greatly affected by the amount of photosynthetic tissue present at the beginning of that period and it is suggested that this is a partially hidden cost of winter and early spring grazing which should be more fully researched.
Evaporation-based drying rate of forage: effects of desiccants and crop density
Authors: Pitt R. E.
Published: March 2009

The application of chemical desiccants to lucerne and red clover after cutting is studied from the standpoint of increasing the drying rate in relation to pan evaporation. Significant increases in the evaporation-based drying constant are found on both first and second cuttings of these crops, but the savings of a full day's drying time is expected only for second-cut lucerne in the north-eastern U.S. climate. The effect of crop density on drying rate is also studied. In conjunction with a theoretical analysis, it is determined that the drying constant varies as γ-0.65, where γ is the areal density. The evaporation-based drying constant is then related to crop yield and the ratio of cutting width to windrow width.
Histochemical studies on bovine sweat glands
Authors: Yang S. H.
Published: March 2009

1. Histochemical tests have been applied to the socalled sweat glands and their secretions of Zebu and Ayrshire cattle, the former to only a limited extent.

2. For skin specimens of Ayrshire cattle positive reactions were obtained for ribonucleoprotein, arginine and alkaline phosphatase. Negative reactions were obtained for desoxyribonucleoprotein and acid glycerophosphatase.

3. Neither the sweat glands of Ayrshire cattle nor those of Zebu cattle gave positive reactions for fats, lipids or cholesterol and its esters, although these were all present in the sebaceous glands of both breeds. Detectable amounts of phospholipid were not found in the sweat glands of the Ayrshire cattle and their secretions.

4. The chemical composition of the secretion of bovine sweat glands differs markedly from that of human eccrine or apocrine sweat glands in not containing detectable amounts of glycogen, lipids and associated compounds or iron.
Cell division, cell death and hepatic DNA in relation to liver hypertrophy and regression in breeding ewes
Authors: Fell B. F. , Campbell Rosa M.
Published: March 2009

Lactation in ewes is associated with hypertrophy of the liver, due to cell proliferation and enlargement. The mean diameter of hepatic parenchymal cell nuclei increased after parturition to reach a maximum at 6 weeks, after which there was a decline.

The liver regressed in weight after weaning but total DNA declined less than liver weight and remained elevated in comparison with livers of unmated ewes, while DNA concentration increased. Total liver DNA remained relatively high for approximately 6 months. It is suggested that the final fall to control values was associated with cell death and disorganization of the hepatic parenchyma.

These results imply that the life span of one type of liver parenchymal cell may be at least 6 months.
Genotype x environment interactions in mixtures of herbage grasses
Authors: England F.
Published: March 2009

The technique of regression on environmental index is used to examine the behaviour of varieties in monoculture and mixture. It is shown that, sometimes, single regressions for each variety do not provide an adequate explanation of the interactions between varieties and environments.
Comparative semen characteristics of Corriedale, Marwari and Jaisalmeri rams maintained under hot arid conditions
Authors: Mittal J. P. , Ghosh P. K.
Published: March 2009

This paper describes the comparative semen characteristics (volume, motility, sperm density, number of sperms, percentage live and abnormal sperms) of Corriedale (exotic) and Marwari and Jaisalmeri (indigenous) rams during the summer and rainy seasons under the arid conditions of Jodhpur, in northwestern India. Except for sperm density, the semen of indigenous animals was superior to that of the Corriedale, although the differences recorded were not of a magnitude to cause the Corriedale sheep to be considered reproductively ineffective under hot arid conditions, if managed properly. The present findings do not conform to the earlier views of the prevalence of ‘summer sterility’ in Corriedale rams observed under hot humid conditions but there appears to be a negative relationship between semen quality and atmospheric humidity. The Corriedale sheep are recommended for improving the sheep sector in the desert areas of Rajasthan.
Effects of single or split applications of nitrogen fertilizer to in situ sugar-beet seed plants in the spring of their second year's growth
Authors: Longden P. C. , Johnson M. G.
Published: March 2009

Nine field experiments (1970–5) investigated the effects of single or split applications of nitrogen fertilizer in February, March, April and May to in situ sugar-beet seed plants in their second year's growth. All experiments were within commercial crops of existing multigerm and monogerm varieties grown on fertile, deep soils in south Lincolnshire, north Cambridgeshire and Northamptonshire and on shallow limestone soils in the Cotswolds.

Yield of seed averaged over years and sites ranged from 4·3 to 4·6 t/ha and so was not affected by nitrogen treatments, which also did not noticeably delay harvest. The usable proportion of seed from multigerm crops was 350–650 g/kg, and from monogerm ones 90–200 g/kg but neither was affected by nitrogen treatment. Application of nitrogen in May reduced laboratory germination by about 3% and seedling emergence in the field by about 5 seedlings per 100 fruits sown. The proportion of single seedlings fmonogermity') was not affected by nitrogen treatments, although it was affected by the monogerm or multigerm nature of the crop. An attempt to assess seed vigour was made by determining average seedling weight when grown in the field in the year following harvest, but results were inconsistent. Leaf petiole nitrate concentrations declined progressively throughout the season, but were increased by about a quarterin the month following nitrogen application. At all times they were large and probably not limiting growth. The test had no value for predicting nitrogen application rates or times.

In practice it appears that the spring top dressing of nitrogen fertilizer should be made as a single application at the end of February or as soon as possible thereafter.
Effects of farmyard manure and phosphorus and potassium fertilizers on soil properties in rice-wheat rotation
Authors: Formoli G. N. , Prasad R.
Published: March 2009

The effects of farmyard manure (FYM) and P and K fertilizers on soil properties were studied at the end of a 3-year (1972–5) field experiment at New Delhi, India. Each year a crop of rice and wheat was grown. FYM was applied at 0 or 15 t/ha, phosphorus at 0, 30 and 60 kg P2O5/ha and potassium at 0 or 60 kg K2O/ha. Treatments included application of manure and fertilizer to rice or wheat alone or to both the crops. FYM application increased organic C, total N and available K and P in the soil, the effects being greater when both rice and wheat received FYM. Application of FYM slightly decreased the soil pH. Phosphorus and potassium fertilizer increased available P and K in the soil, respectively.
The effect of diet and blood-plasma magnesium concentration on the endogenous faecal loss of magnesium in sheep
Authors: Allsop T. F. , Rook J. A. F.
Published: March 2009

Two experiments are reported in which mature, castrated male sheep were used to study the effect of a change of magnesium status, as induced by a continuous intravenous infusion of magnesium, on the faecal output of magnesium. In the first experiment, three artificial diets differing markedly in fibre content but extremely low in magnesium were used and in the second experiment, natural diets of frozen grass and of hay and ground barley.

With the artificial diets, unit change in plasma magnesium concentration gave the same increase in faecal magnesium output with all three diets but on average faecal magnesium output was highest for the diet containing the highest content of fibre and least for the diet containing an intermediate amount of fibre, and the differences, though small, were statistically significant. With the natural diets, there was no significant difference between diets in the increase in faecal magnesium output in response to a change of plasma magnesium concentration but the order of response was much greater than for the artificial diets. It is concluded that absorption of magnesium from the gut is depressed at high plasma magnesium concentrations.
The effect of treadmill slope on the relationship between heart rate and energy expenditure in cattle walking on treadmills
Authors: Sneddon Jennifer C.
Published: March 2009

Two steers (Bos indicus and Bos indicus x Bos taurus) were acclimatized to an ambient temperature of 30 °C before working at this temperature on two treadmills (gradients 0 and 6°) for 2 h (one on each treadmill) whilst carrying a load equivalent to 10% of body weight. The study was then repeated at an ambient temperature of 15 °C. The effect of variation between animals, ambient temperature and rate of energy expenditure were tested on the linear regression model EEw = A PHR + B (where EEw is the energy expenditure (w/kg0·75) and PHR is the percentage increase of working heart rate over resting heart rate).

Animal and ambient temperature had no significant effect on the model. The gradient of the regression line was significantly greater (P < 0·01) when the animals were expending energy at the higher rate (about 30 W/kg live weight0·75) than when they were expending energy at the lower rate (about 14 W/kg live weight0·75).
Post-natal development, dimensions of the skin follicle population and birthcoat follicular origin in Barki and ⅜ Merino lambs
Authors: Guirgis R. A. , Amin S. O. , Ghanem Y. S. , EL-Sayed N. A.
Published: March 2009

In a study of two breed groups, coarse wool Barki and ⅜ Merino ⅜ Barki, data were obtained on skin histology from birth to the age of 1 year, birthcoat fibre type arrays and fibre-follicle relationship.

The ⅜ Merino exceeded Barki lambs in the maximum S/P ratio, values of which were 3·40 and 5·64 obtained at 6 and 8 months in Barki and ⅜ Merino respectively.

Internal diameters of primary follicles ranged from 39·0 to 64·7 and from 41·0 to 56·8 μm; those of secondaries ranged from 19·8 to 34·9 and from 22·6 to 33·3 μm in Barki and ⅜ Merino respectively.

The ratio of primary to secondary follicle diameters showed high values in both breed groups; averages were 1·89 and 1·71 for internal diameter and 1·86 and 1·71 for external diameter in Barki and ⅜ Merino respectively.

Birthcoat fibre type arrays were mostly saddle, only 8·3% were plateau (P3) in both breed groups.

In Barki primary centrals grew halo hairs, super sickle (A, A′, B), primary laterals produced super sickle (A, A′, B), sickles, coarse and medium curly tips, and secondaries mostly grew medium and fine curly tips and histerotrichs.

In ⅜ Merino primary centrals produced halo hairs, super sickle (A, A′, B), primary laterals grew super sickle (A, A′, B), sickles, medium curly tips, and secondaries produced medium and fine curly tips and histerotrichs.
Effects of condensed tannins in Lotus pedunculatus on its nutritive value for sheep. 1. Non-nitrogenous aspects
Authors: Waghorn G. C. , Shelton I. D. , McNabb W. C.
Published: March 2009

Lotus pedunculatus was grown under high fertility conditions and its nutritive value was determined in a feeding trial with sheep at Palmerston North, New Zealand in 1989. The condensed tannins (CT) accounted for 5·5 % of lotus dry matter (DM) and its effect on digestion was evaluated by giving an intraruminal infusion of polyethylene glycol (PEG) to six of the sheep (PEG group). PEG preferentially binds with CT so that the lotus becomes essentially CT-free.

The experiment was carried out with 14 sheep (six PEG and eight ‘Tannin’) held in metabolism crates indoors and given freshly cut lotus hourly, for 32 days. This paper presents data relating to carbohydrate and mineral digestion, together with aspects of rumen function.

Digestibility of lotus DM was 68%, and the digestibility of fibre was not affected by CT. Infusion of PEG increased rumen concentrations of NH3 and volatile fatty acids (P < 0·001) but effects on molar ratios of VFA were inconsistent with time. CT reduced rumen degradation and absorption of sulphur and increased net absorption of both phosphorus and zinc, but other effects on mineral digestion were small.

Although the lotus was offered at c. 90% of ad libitum, intakes of the tannin sheep began to decline after c. 15 days of feeding and were c. 12% lower than those of the PEG sheep at the end of the trial (P < 0·05). At slaughter, rumen pool sizes were similar for the two treatments but the Tannin sheep had a lower fractional outflow rate, which suggests a slower rate of digestion in the rumen. Growth rate and wool production were similar for sheep on both treatments. It is concluded that the CT in Lotus pedunculatus grown under high fertility conditions had little effect on fibre and mineral digestion but the depression in DM intake reduced its nutritive value for sheep.
Intercropping wheat and barley with N-fixing legume species: a method for improving ground cover, N-use efficiency and productivity in low input systems
Authors: Reynolds M. P. , Sayre K. D. , Vivar H. E.
Published: March 2009

Two cereal cropping systems are described which, through the introduction of a leguminous intercrop, increased productivity, nitrogen output and ground cover of the systems in the absence of added nitrogen fertilizer. Nitrogen-fixing legumes were cultivated between rows of wheat or barley grown at low levels of soil nitrogen, and mostly under rainfed conditions, in Mexico between 1989 and 1992. None of the legumes tested reduced yields of the cereal crop in comparison to controls where cereal yields were in the range of 1–4 t/ha, while the extra total biomass from legumes in some cases more than doubled productivity. Different legume crops were tested to demonstrate the adaptability of the system to the varying needs of farmers. The intercropped legumes achieved dry biomass yields as high as 6·5 t/ha in the case of a sequentially cropped forage crop of hairy vetch, or 1·4 t/ha of dry beans plus 3·5 t/ha of green residue in the case of Vicia faba. Total biomass in the intercropped situation gave land equivalent ratios as high as 1·54. Light measurements inside the crop canopies indicated that the intercropped systems intercepted a higher proportion of the incident solar radiation than the cereal monocrop, presumably accounting for the large differences in total biomass produced. In addition, with leaf nitrogen levels of 3·8%, it is assumed that the intercropped legumes fixed considerably more nitrogen than was removed by the wheat crop. The potential of the system to stabilize erodible soils by increasing ground cover as well as by raising inputs of soil organic matteris discussed.
The use of a land suitability model to predict where autumn-sown, determinate genotypes of the white lupin (Lupinus albus) might be grown in England and Wales
Authors: Siddons P. A. , Jones R. J. A. , Hollis J. M. , Hallett S. H. , Huyghe C. , Day J. M. , Scott T. , Milford G. F. J.
Published: March 2009

A model was developed to assess the suitability of land in England and Wales for growing newly developed genotypes of autumn-sown determinate white lupins. The model used soil pH, the number of degree-days accumulated for mainstem leaf production before the apical meristem of the mainstem became floral, and the number of machinery work days in autumn. Interactions between these three components were used to set thresholds to determine land suitability within 5 × 5 km grid squares of the National Soil Map.

Of the potential 13·75 Mha of arable land in England and Wales, a total of 7·54 Mha are well or moderately suited to growing these lupin genotypes. This is equivalent to c. 2 Mha of land within the arable rotation each year. It was estimated that, because of low soil pH, lupins would be the preferred legume on 0·3 Mha out of this 2 Mha. The model was also used to assess the risk of soil acidification and nitrate leaching following mineralization of lupin residues. This exercise indicated that there was little risk of either on much of the land suited to lupins.
A quantitative evaluation of the comparative value of six fertilizer–nitrogen sources for potatoes
Authors: Swaminathan K.
Published: March 2009

Six fertilizer–nitrogen sources, each at three levels, together with a control of no fertilizer–nitrogen were compared in field trials in two consecutive crop seasons on a sandy soil comparatively deficient in nitrogen at Patna, Bihar. Four mathematical models were fitted to the potato yield data in order to evaluate the relative availability indices of the individual fertilizers. Data collected on final stand and ‘emergence rate’ index (Bartlett) showed that while urea applications gave rise to a comparatively low speed of emergence, with observed shoot injuries, nitrate of soda caused poor final stands. The other fertilizers had no effect on either the final stand or the speed of emergence.

Sulphate of ammonia was chosen as the standard fertilizer for the present study. Ammonium sulphate nitrate was as good as or even slightly better, while ammonium chloride and calcium ammonium nitrate were of intermediate efficiency, in that order. Urea and nitrate of soda were decidedly poor as nitrogen sources for potatoes under the conditions of the study. The concurrent Mitscherlich curves model was found to represent the behaviour of these fertilizers with a good measure of fit.

The performance of the six fertilizers is discussed in the light of the availability of NH4+ and NO3-, the phytotoxicity of urea and nitrate of soda, and the harmful effects of Cl-. It is concluded that ammonium sulphate nitrate is the best carrier of nitrogen among those studied for potatoes under the conditions set forth.
The effects of components of body weight on reproductive efficiency in the Merino ewe
Authors: Guerra J. C. , Thwaites C. J. , Edey T. N.
Published: March 2009

Groups of mature Merino ewes selected on the basis of either large or small bodysize were differentially fed during a pre-experimental period to produce subgroups of high and low body condition. These levels of body condition were maintained for 2 weeks before mating and for the first 5 weeks of gestation. Thereafter, the four subgroups grazed together until lambing.

Big ewes had more multiple ovulations than small ewes (14/41 υ 6/53; P < 0·01), and there was a significant linear regression of ovulation rate on body size. Body condition was positively related to the incidence of multiple ovulations, but the regression of ovulation rate on body condition at mating failed to reach significance. Body weight was significantly related to both ovulation rate and the incidence of multiple ovulations, and proved to be a more effective predictor of ovulation rate than either body size or condition.

These results make it clear that size and condition, the two components of body weight, each have a considerable independent influence on some aspects of reproduction, and that the precision of some experiments and the effectiveness of some production routines could be improved by considering them separately.
Improvement of wool production and quality by the use of sheep rugs on Gansu Alpine Fine wool sheep in north-west China
Authors: Davis G. P. , You Z.-F. , Crowe D. W. , Whiteley K. J. , Ma H.-Z. , Song S.-Z. , McGuirk B. J.
Published: March 2009

Fine wool in China is characterized by severe dust contamination and substantial tip weathering. In an attempt to improve wool quality, synthetic rugs were fitted to ewes and a range of raw wool characteristics was monitored. Two trials were carried out in successive years: a pilot trial (June 1985 to June 1986) involving 100 ewes wearing rugs and 75 controls, and a main trial (June 1986 to June 1987) involving 250 ewes with rugs and 250 controls. The rugs were fitted to ewes after shearing and remained on until shearing the following year. Wool from ewes with rugs was significantly better in almost all the characteristics measured (P <0·05) than wool from sheep without rugs. Clean fleece weight was improved by 15% over the two trials, yield and wax content were increased, and dust content and dust penetration were substantially reduced. Staple length and strength were increased, and dust content and dust penetration were substantially reduced in the main trial. Several style characteristics were measured using a prototype image analysis system and these also showed wool from sheep wearing rugs as being of better quality than wool from sheep in the control group. The only negative result was an increase in yellowness, in the greasy state only, due to the higher wax content in the sheep wearing rugs and the yellow nature of the wax of Gansu Alpine Finewool sheep – probably due to their genetic background. Wool from sheep wearing rugs would be expected to perform better in processing than wool from unrugged sheep.
Magnesium metabolism in lactating goats fed on grass diets differing in mineral content
Authors: Johnson C. L. , Powley G.
Published: March 2009

A balance experiment was carried out using four young lactating goats in a Latin square design, fed with perennial ryegrass (Lolium perenne) from plots that had received 377 kg K/ha (diet 1); 63 kg K plus 377 kg Na/ha (diet 2); 188 kg K plus 188 kg Na/ha (diet 3) or no fertilizer (control diet 4).

The apparent availability of Mg was high in all the grass diets (0·355–0·469); it was significantly depressed (P < 0·05) when the intake of K was high (diet 1); but was not significantly different when a high intake of K was accompanied by a high intake of Na (diet 3).

There was a significantly lower (P < 0·05) apparent availability of Na in diet 4 and a significantly higher (P < 0·05) apparent availability of K in diet 3. There were no significant differences in the apparent availability of Ca.

The plasma Mg concentration was not significantly affected by any dietary treatment but did decrease temporarily when diets were changed.

There were no significant effects on mineral concentrations in the milk.
Adverse effects on reproductive performance and lameness of feeding grazing dairy cows partially on silage indoors
Authors: Phillips C. J. C.
Published: March 2009

Eighty autumn-calving (A) and 82 spring-calving (S) British Friesian cows were divided during the grazing season into two groups: one group received silage overnight indoors and grazed herbage during the day (partial storage feeding, P) and the other was conventionally set-stocked (C). The effects of the four treatments (AC, AP, SC and SP) on reproductive performance and herd health are reported for the 27-week grazing season and the subsequent 25-week housed period in 1985/86 in North Wales. Calving to conception interval was not affected by treatment but, in treatment SP, pregnancy rate to all services was lower and number of barren cows was greater than in the other treatments. Partial storage feeding increased the incidence of under-run heel and laminitis in the early part of the grazing season, and this was reflected in poorer locomotion. Treatment SC resulted in an increased incidence of punctured sole with pus later in the grazing season. Both autumn-calving treatments resulted in a large decrease in lameness and poor locomotion at drying off, but these increased in the autumn before housing. The mean duration of each lameness incident was 1·88 months and, in 40 out of 97 incidents, lameness was preceded by uneven gait. The incidence of lameness and poor locomotion was low for all treatments throughout the housed period. It is concluded that a high standard of buildings and reproductive and herd health management is necessary for partial storage feeding to be practised successfully.
Interaction of Compudose 200® and resistance to parasites on growth of steers of two cattle breeds
Authors: Frisch J. E. , Hunter R. A.
Published: March 2009

This study sought to determine whether increases in live weight (LW) of steers implanted with Compudose 200®, a growth promotant that contains 17β-oestradiol, arose in part from increases in resistance of those steers to cattle ticks and gastro-intestinal nematodes (worms) to which the steers were exposed while they were growing. Half of a group of interbred Hereford × Shorthorn (HS) and interbred Brahman × HS (BX) steers was implanted with Compudose 200 on two occasions 200 days apart. Half of each of the implanted and nonimplanted groups in each breed was treated every 3 weeks to control cattle ticks and worms. All animals grazed together and were regularly monitored for parasite burdens and LW changes. Both breeds responded positively to Compudose 200, to which BX responded most, and to treatment to control parasites. Resistance to either ticks or worms was unaffected by the presence of the implant so that, within each breed, increases in LW gain in response to the implant were similar regardless of parasite control. Thus the increases in LW gain resulting from the use of Compudose 200 arose directly from the action of the implant on metabolism, not indirectly through any effect on resistance to parasites.
Catchment basin water harvesting as a means of improving the productivity of rain-fed land in upland Balochistan
Authors: Rees D. J. , Qureshi Z. A. , Mehmood S. , Raza S. H.
Published: March 2009

Catchment basins were prepared within bunded fields from 1986 to 1988, with ratios of catchment area to cropped area of 1:1 or 2:1. Annual rainfall varied from 102 to 282 mm.

Run-off from the catchment basins increased water storage in the cropped areas by 55 and 43% of the rain falling on the catchments in the 1:1 and 2:1 treatments, respectively. Yields increased considerably on a cropped area basis by water harvesting, but not always sufficiently to compensate for the loss of cropped land. Averaged over all trials, yields from the 1:1 treatment were 95% of the control yields. Yields-in the 2:1 treatments were reduced by waterlogging damage.

The cost of catchment set-up was low compared with the reduced seed and ploughing costs in the water-harvesting treatments, resulting in 18 and 31% reductions in overall costs for the 1:1 and 2:1 treatments, respectively. Net benefits for the 1:1 treatment equalled or exceeded those of the control, but were 32% lower for the 2:1 treatment. Within-field water harvesting with a 1:1 crop: catchment ratio thus reduced risk by reducing investments in seed and animal draught power, whilst maintaining yields and net benefits, suggesting that it could be of considerable benefit to farmers in an environment with a high risk of crop failure. Catchment preparation on unused land adjacent to cropped land, and further research aimed at reducing waterlogging damage, could both lead to improvements in farmers' circumstances in upland Balochistan.
Effects of protein supplementation of grass silage on the performance and carcass quality of beef cattle
Authors: Steen R. W. J.
Published: March 2009

Two experiments (E1 and 2) were carried out in Northern Ireland in 1988/89 to examine the effects of a wide range of supplementary protein intakes given with grass silage-based diets on the performance and carcass composition of beef cattle, and to compare diets based on silage and dried forage. The five treatments used consisted of grass silage offered ad libitum and supplemented with 2·5 kg dry matter (DM) of barley-based concentrates containing (1) zero, (2) 0·2, (3) 0·4 and (4) 0·6 extracted soyabean meal and (5) artificially dried grass and hay supplemented with 3·3 kg concentrate DM. Experiments E3 and 4 were carried out in 1991/92 to examine the responses in ration digestibility, silage intake and animal performance to supplementary protein in relation to the requirements recommended by the United Kingdom Metabolizable Protein System. The two treatments consisted of grass silage offered ad libitum and supplemented with 3·2 kg DM of (1) barley and (2) 0·8 barley and 0·2 soyabean meal. The silages used were well preserved, containing on average 200 g DM/kg; 143 g crude protein (CP)/kg DM; 79 g ammonia-N/kg total N and 734 g digestible organic matter/kg DM. The cattle were castrated males of medium to late-maturing breed type and were initially 13 months old and 396 kg liveweight. Increasing protein intake did not affect ration digestibility, silage DM intake or animal performance in any of the four experiments, despite the fact that the effective rumen degradable protein (ERDP) intakes in the diets supplemented with barley alone were only 80–85% of ERDP requirements. However, increasing protein intake tended to increase carcass fatness in all experiments, the effect being significant (P < 0·05) for the lipid concentration in the M. longissimus dorsi muscle in E1 and 2. Offering the dried forage-based diet rather than an isonitrogenous silage-based diet did not affect carcass fatness. It is concluded that supplementing well preserved grass silages with mixtures of barley and soyabean meal, rather than with barley alone, did not affect ration digestibility, silage intake or animal performance but tended to increase carcass fatness, especially marbling fat, despite the fact that ERDP intakes for the diets with the lowest protein concentration were only 80–85% of requirements given by the United Kingdom Metabolizable Protein System.
Thermoperiodicity of crop plants and strategies for climate control
Authors: Markovskaya E. F. , Sysoyeva M. I. , Bezdenezhnykh V. A.
Published: March 2009

A method for investigating the thermoperiodicity of crop plants is described. On the basis of our experimental results and published data, crop plants were assessed to establish whether they were thermoperiodic or not. Tomato and maize were classified as thermoperiodic species. Cucumber, beans, peas, oats and wheat were not thermoperiodic. Strategies for climate control based on the estimation of optimum temperature are proposed. These can be used to minimize energy consumption and, together with other environmental treatments, could optimize the yield of glasshouse crops.
Growth and development of the pod wall in spring rape (Brassica napus) as related to the presence of seeds and exogenous phytohormones
Authors: Srinivasan Ancha , Morgan D. G.
Published: March 2009

Pod wall photosynthesis is known to contribute to nearly one-third of rape (Brassica napus) seed weight. The relationship between the number of seeds and the growth of the pod wall, and the effects of single and mixed applications of gibberellic acid (GA), naphthyl acetic acid (NAA) and benzyl adenine (BA) on development of the pod wall were, therefore, examined in potted plants of spring rape under glasshouse conditions.

The size and weight of the pod wall were closely associated with the number of seeds per pod, and a stronger development of tissues was observed in the presence of seeds. Application of BA alone or in combination with GA (GA + BA) to emasculated flowers induced the development of parthenocarpic pods similar in size and shape to the untreated seeded pods. NAA applied singly or in mixtures produced abnormal pods. BA enhanced cell division in all tissues while GA and NAA caused expansion of parenchyma in the mesocarp. Application of BA or GA + BA at 1–5 rather than at 11–15 days after flower opening led to the development of bigger pods. Younger pods responded more than the older ones when they were treated simultaneously. BA or GA + BA application to nonemasculated flowers on the terminal raceme delayed senescence in both basal and apical pods but it increased pod size only in the latter. The balance of cytokinins and gibberellins within a pod seems to play an important role in regulating the growth of the pod wall.