bluuebunny/crossref_metadata_2025 huggingface dataset:
The composition and nutritive value of seeds hays
Authors: Ferguson W. S. , Watson S. J.
Published: March 2009

The examination of 108 first year seeds hays showed the average crude protein content to be 9·0 ― and the average crude fibre content 25·7 ―. The crude protein content varied from 5·0 to 13·5 ― and was directly associated with the clover content.

Figures obtained on hays cut in the second and third years of the ley suggest that the protein content falls, and the crude fibre content rises, with increasing age of ley.

The composition and digestibility of twenty first year hays were determined and the average figures quoted for hays of high, medium and low clover content. The starch equivalent values of these hays were high and moderately constant, varying from 33·3 to 41·2, average 36·8. The protein equivalent values varied from 1·8 to 8·4 ―, average 5·1 ―.

The composition and digestibility of four samples of second year seeds hay, two samples of third year hay, one sample of second cut hay in its first year and one sample of lucerne and cocksfoot hay were also determined.
On the breeding season in the sheep
Authors: Hammond J.
Published: March 2009

Ewes. There was some variation from year to year in the times of onset and end of the breeding season; on the average it was evenly spaced on either side of the shortest day. Occasionally ewes were served and became pregnant at times well outside the normal limits of the breeding season. Lambs were allowed to suckle the ewes for as long as they would; when lambing occurred more than about 100 days from the start of the season there was no delay in onset of heat in the ewe. When lambing was later there was some delay, but the duration of the lactation anoestrum shortened to a minimum near the middle of the season and then lengthened again.

In the first half of the season the period of the oestrous cycle lengthened slowly and steadily; in the second part it became more variable, there was first a slight shortening, but upon the whole it continued to increase in length. From the start of the season the frequency of twinning increased quickly to a peak in about November and then declined for the rest of the season. At the end of the season there was a high proportion of services not fertile.

Lambs. Growth in the first 2 months was greatest in those born in May; in the fourth to sixth months it was greatest in the earliest born and least in the latest, the highest weight at 6 months old being reached by those earliest born.
Bracken ensilage
Authors: Ferguson W. S. , Neave O.
Published: March 2009

Bracken cut in June was ensiled in various ways, and some of the products were examined for chemical composition, digestibility and palatability. The main findings were:

1. Overheated silage was moderately palatable to sheep and cattle, but its digestibility was low and it approximated to wheat or barley straw in feeding value.

2. Silage subjected to less heat was unpalatable, and in some cases was absolutely refused by sheep. The ensiled stems were preferred to the leaves. The digestibility was low but slightly better than that of the overheated silage.

3. Ensiling seriously affects the digestibility of bracken protein. In two silages none of the true protein was digestible, and in one the digestibility of this constituent was only 12·9%.

It is concluded that the ensiling of bracken is unlikely to prove profitable.
Fermentation in the rumen of cows given rations containing hay and flaked maize or rolled barley in widely different proportions
Authors: Sutton J. D. , Johnson V. W.
Published: March 2009

Three dry cows, each fitted with a permanent rumen fistula, were fed hay and flaked maize or hay and rolled barley in widely different proportions. All rations were offered at 7 kg dry matter daily for 3 weeks following hay alone. The cows refused all cereal 3 or 4 days after introduction of rations including 80 and 100% flaked maize; recovery of intake occurred in most instances within a further 3–10 days. On the 100% flaked maize ration, the refusals were associated with very low pH and high concentrations of lactic acid in the rumen.Refusalsof rolled barley were small and showed no clear pattern.

Rumen fermentation was reasonably stable during the last week of each period except with the 100% barley rations. On the rations containing flaked maize, molar proportions of volatile fatty acids (VFA) varied widely but on only one occasion did the proportion of acetic acid fall below 55% and in two cows that consumed flaked maize alone, the proportion of acetic acid in the rumen exceeded 60%. On the rations containing rolled barley, increasing proportions of barley were associated with large decreases in the proportion of acetic acid and increases in the proportion of propionic acid. The maximum proportion of n-butyric acid was found on the rations containing 50% cereal.

It is suggested that, when large proportions of cereals are fed, the proportions of VFA bear no clear relationship to the crude fibre content of the ration but that an association with rumen pH may exist.
The metabolism of fowl sperm in different diluents
Authors: van Tienhoven A.
Published: March 2009

Dilution of fowl semen with phosphate or saline diluents depressed respiration, while dilution with seminal plasma did not affect respiration. Dilution with Tyrode solution resembled dilution with seminal plasma with respect to respiration. The effect of Tyrode solution seemed to be mainly due to its NaHCO3content.

The effect of Ca, Mg and K ions depended on the anions in the diluents. Phosphate depressed respiration and glycolysis when it replaced saline in the Tyrode diluent.

Dilution did not consistently increase respiration and in most cases depressed respiration.

Fowl sperm preferentially utilized glucose when glucose and fructose were initially present in equal concentration in the diluent. The sperm metabolize glucose at a faster rate than fructose. No evidence was found for the formation of glucose from fructose under our experimental conditions.

Initial respiration and glycolysis of fowl semen was depressed by the addition of glycine to the Tyrode diluent. However, the glycine addition resulted in a less sharp decrease in the hourly respiration rate.
The post-natal growth of the visceral organs of the lamb I. The growth of the visceral organs of the grazing lamb from birth to sixteen weeks of age
Authors: Wardrop I. D. , Coombe J. B.
Published: March 2009

1. Thirty-two single lambs were grazed together on pasture. At weekly intervals, from birth to 112 days of age, two lambs were slaughtered and various organs weighed immediately after death. Also the alimentary tracts of seven adult sheep were obtained immediately after death.

2. The rumen had the fastest growth rate of the four stomachs, followed by the reticulum, omasum, and abomasum, in that order.

3. Immediately after birth the four stomachs altered rapidly in their relative proportions, but by about 66 days of age they had reached approximately adult proportions.

4. The weights of the liver, heart and kidneys, relative to live weight, decreased during the first few weeks of life, and thereafter remained constant.

5. The weight of the spleen, relative to live weight, increased during the first week of life and thereafter remained constant.
The effects of grazing intensity on herbage consumption and animal production: III. Dairy cows grazed at two intensities on clean or contaminated pasture
Authors: Greenhalgh J. F. D. , Reid G. W.
Published: March 2009

On three occasions in May—July one half of a ryegrass pasture was grazed intensively by cattle and the other was mown. In August and September these areas, designated fouled (F) and clean (C) respectively, were each strip-grazed by two groups of five cows. One group on each area had a herbage allowance of 11·4 kg dry matter per cow per day (C11 and F11) and the other 20·4 kg (C20 and F20).

Before the August-September grazing the fouled area had 2·8% of its surface covered by faeces. After this grazing 23 % of the F n area and 34 % of the F20 area were classified as having been rejected by the cows. However, the upper parts of the sward on these rejected areas were in fact grazed. There were only small differences in N and soluble-carbohydrate contents between the herbages offered and rejected.

Organic-matter digestibility (%) and intake (kg/cow per day) for the four groups were: C11, 73·0 and 10·5; C20, 74·9 and 11·7; F11 , 74·4 and 9·6; F20, 77·0 and 10·6. The C11 cows consumed all the herbage allowed to them, but the F11 rejected 13%. Digestible organic matter intake was affected more by grazing intensity than by fouling; this was the case also for milk yield, milk composition and the live-weight change of the cows.
Experiments on the nutrition of the dairy heifer: VIII. Effect on milk production of level of feeding at two stages of the lactation
Authors: Broster W. H. , Broster Valerie J. , Smith T.
Published: March 2009

Eighty Friesian heifers were used to study the effect on milk production of two fixed levels of intake at two stages of the lactation. The rations were estimated to contain 7·9 and 6·2 kg starch equivalent per day, with adequate protein content. The heifers were allocated at random to these two levels of intake for weeks 1·9 of lactation and re-allocated at random to them for weeks 10–18 of lactation. Apart from minor variation the heifers were all fed alike for the remainder of the lactation.

The higher level of feeding increased yields of milk and milk solids and solids-not-fat content in each period but had a smaller effect in mid- than in early lactation, a trend which was shown to continue further into later lactation. It also conserved body reserves.

There was a residual effect in weeks 10–18 from the level of feeding in weeks 1–9 of lactation. This was directly additive to the effects of the current level of feeding. Those animals which had received the higher level of feeding in weeks 1–9 yielded more milk of higher solids-not-fat content than those which had had the lower level of feeding in weeks 1–9. The former group gained less live weight. The effect on milk production over the full lactation from additional feeding in early lactation was three times that observed in early lactation itself. Additional feeding in mid-lactation did not have a residual effect.

The absolute output of milk per unit of food over the 18-week period was greatest for that group which had received the lower level of feeding throughout, followed by the group which received the higher level of feeding in weeks 1–9 only. This superiority was achieved at the expense of body reserves. There was a negative regression of live-weight change on milk production.

Estimated intakes of metabolizable energy agreed closely with requirements for milk production as indicated by the Agricultural Research Council (1965).
The nutrition of the bacon pig. I. The influence of high levels of protein intake on growth, conformation and quality in the bacon pig
Authors: Woodman H. E. , Evans R. E. , Callow E. H. , Wishart J.
Published: March 2009

The present practice of basing payment for bacon pigs not merely on carcass weight, but also on carcass quality as expressed in the factory grading results, has led necessarily to an enlargement of outook on the part of the investigator in the domain of swine nutrition. The interest of the experimenter in the past has tended to be restricted to such questions as the influence of nutritional factors on the rate of live-weight increase and the efficiency of food conversion, the problem of how feeding may influence carcass quality and conformation not having received the attention its importance merited.

While the questions of the rate of growth and the efficiency, in terms of meal consumption, with which such growth is achieved are still matters of primary economic importance, it is realized that much more attention must be devoted than heretofore to the study of carcass quality and conformation in relation to feeding. In present circumstances, a nutritional investigation can scarcely be considered complete unless a substantial part of the research is carried out in the bacon factory following the slaughter of the experimental animals.
The base status of Scottish soils. I. The effects of lime on five typical soils from north-east Scotland
Authors: Mitchell R. L.
Published: March 2009

The effects of lime on five soils representative of types from northeast Scotland have been studied and different lime requirement methods compared.

Laboratory analyses including mechanical and ultimate chemical analyses, pH, exchangeable cation and lime-requirement determinations were carried out on samples taken before and at two intervals of 6 months after the application of lime.

In some cases the maximum effect of the lime applied occurs within 6 months, in others neutralization is continued during the second 6 months.

The change in pH value varies, according to the soil type, from 0·5 to 1·0 pH units per ton of calcium oxide applied per acre.
The effect of maturity and leafiness on the intake and digestibility of alfalfas and grasses fed to sheep
Authors: Troelsen J. E. , Campbell J. B.
Published: March 2009

The effect of maturity on the nutritional quality of hay from two alfalfa varieties and four grass species was studied. Each hay was harvested at six different stages of growth, chopped in 4–6 cm lengths, and fed to sheep in quantities of 10% in excess of voluntary intake. The relationship between intake (Y) and digestibility (X) of dry matter was best expressed by regressions of the form: Y = a + b1X + b2X2. The rate of intake declined 1·5 g daily per kg0·75 of body weight per unit decrease in digestibility percentage, and was the same for both alfalfa and grass hays. However, the intake of alfalfa hay was about 10% higher than that of the grass hays of similar digestibility. No differences in the relationship between intake and digestibility (P < 0·05) were observed between the two alfalfa varieties or between the four grass species. When the nutritional quality was expressed as voluntary intake of digestible organic matter daily per kg0·75 of body weight, and time of harvest as day-number of the year, the difference in quality between the six kinds of hay was very small or absent at the beginning of the season (immature to prebloom) and increased toward maturity (dough stage to seed ripe). The decline in quality of alfalfa hay was slower than that of grass hay, and ceased at the mature to overripe stage. On the average, voluntary intake of digestible organic matter declined 0·29 g daily for each day delay in harvest time; this decline varied from 1·2% of the daily intake of digestible organic matter in the beginning of the season to 0·6% at the mature stage. Time of harvest ‘accounted for’ 77–89% of the variation in the quality of the hays. The confounded effect of maturity and leanness on the nutritional quality of the hays was expressed best by concave, second degree polynomial regressions. On the average a unit decline in percent leaves corresponded to a decline of 0·58 g and 0·73 g respectively in the daily intake of digestible organic matter from alfalfa and grass hay. This varied from over 1 g early in the season to less than one tenth of a gram late in the season. The confounded effect of leafiness and growth stage ‘accounted for’ over 75% of the variability in nutritional quality. The relationship between intake and digestibility of the alfalfa and grass hays was used to illustrate how voluntary intake of metabolizable energy (percent of requirement for maintenance) from hay of pure or mixed species may be predicted from in vitro digestibility.
Body temperature lability in sheep and goats during short-term exposures to heat and cold
Authors: Johnson K. G.
Published: March 2009

Passive lability of body core temperature during brief exposures to thermal stress is an efficient means of thermoregulation which few species of domestic animals appear to utilize. The body temperature changes of 30 shorn sheep and 10 shorn goats have been measured during standard heat and cold exposures lasting 7 h. During exposures to heat, air temperature was increased from 20 °C to 45 °C then reduced again to 20 °C. Rectal temperatures of goats and Soay, Welsh Mountain, Merino and Clun Forest sheep rose by an average of 1·96 °C, 1·22 °C, 1·04 °C, 0·85 °C and 0·80 °C respectively. All animals had similar increases in respiratory rate. During exposures to cold, air temperature was reduced from 20 °C to about 6 °C then increased again to 20 °C. Rectal temperatures rose by 0·18–0·20 °C in goats and in all sheep except Soays in which they fell by 0·28 °C. All animals showed moderate to vigorous shivering. None of the animals exhibited passive body temperature lability as an adaptation to thermal stress.
The response of perennial ryegrass to nitrogen in various periods of the growing season
Authors: Cowling D. W. , Lockyer D. R.
Published: March 2009

The response of irrigated, perennial ryegrass to fertilizer nitrogen was studied in four consecutive periods of the growing season by applying 0–350 kg N/ha to a fresh sward at the start of each period, and measuring both herbage dry matter and its content of nitrogen.

Responses in yield were highest in the first period, which ended at inflorescence emergence; in this period, both the percentage recovery of nitrogen and the extent of its utilization in producing dry matter were greater than in the later periods. Some damage to the sward was seen following the harvest of grass grown with the high levels of nitrogen in the first period. When the yields were 90% of the predicted maximum the nitrate-N content of the herbage ranged from 1000 to 2000 ppm, except in the first period when it was 200 ppm.

The response curves were used to calculate the nitrogen requirements of the grass which would maintain given incremental yield responses. To produce near-maximum yields, irrigated grass swards may require fertilizer nitrogen equivalent to 2 kg N/ha/day prior to inflorescence emergence, and up to 5 kg N/ha/day for the remainder of the growing season.

The apparent efficiency of conversion of the radiant energy, usable for photosynthesis, into plant energy averaged 3·2%; it did not vary greatly among the four periods.

The experimental results indicate the seasonal requirements of grass for fertilizer nitrogen and some of the implications for animal husbandry are discussed.
The effect of diet on glucose entry rates in sheep
Authors: Ulyatt M. J. , Whitelaw F. C. , Watson F. G.
Published: March 2009

An isotope dilution technique has been used to measure the rate of entry of glucose into the metabolic glucose pool and its rate of oxidation in three sheep given diets of barley (85% barley, 15% protein-mineral-vitamin supplement), dried grass or hay. A latin-square design was used and the sheep were fed continuously from an automatic feeding device.

Despite large differences in the amounts of α-linked glucose polymer and of crude protein supplied by the diets there were no significant differences between treatments in glucose entry rate, in plasma glucose concentration or in the size of the total body pool of glucose.

Calculations based on the specific radioactivity of expired CO2 after 3 h infusions indicated no significant differences between treatments in the percentage of glucose oxidised to CO2 or in the percentage of expired CO2 derived from glucose. The absence of a final ‘plateau’ position in the CO2 activity-time curve, even after 6 h infusions, casts doubt on the validity of these calculations.
An evaluation of Merino wool quality: III. The prediction of uniformity of fleece characters from fleece and skin characters of the birthcoat
Authors: Gallagher J. R.
Published: March 2009

Fibres of anomalous length or diameter are undesirable in the Merino, a breed noted for uniformity of fleece characters. Previous studies which have aimed at estimating adult fleece quality have been based on visual appraisal of the birthcoat. This study was undertaken to test the prediction of uniformity of fibre length at 10½ months and fibre diameter at 15 months from the objective measurement of birthcoat fleece and skin follicle characters.

The results indicated that fibre length uniformity at 10½ months cannot be predicted from measurement of fleece or skin characters at birth. It was found that fibre diameter uniformity at 15 months can be predicted from objective measurement of mean fibre diameter of the birthcoat but not by visual appraisal.
Heavy metal content of plants growing on soils contaminated by lead mining
Authors: Alloway B. J. , Davies B. E.
Published: March 2009

During the nineteenth century several parts of Wales were intensively mined for lead, zinc and copper ores. Fields adjacent to and downstream from the mines became contaminated by air- and water-borne heavy metal compounds. Such fields still contain high concentrations of total lead, zinc and copper together with silver and cadmium, the chief ‘guest’ elements in lead and zinc ores. Extraction of the soils with dilute acetic acid suggested that contaminated soils contained more of these metals that were available to plants (Alloway, 1969; Alloway & Davies, 1971). Some studies of plant composition were made to confirm the evidence from soil extraction and to indicate the extent to which these metals were entering the food chain.
Effect of autumn shearing on breeding activity in Clun Forest ewe lambs
Authors: Dýrmundsson Ó. R. , Lees J. L.
Published: March 2009

Seventy-two Clun Forest ewe lambs were randomly stratified into three groups (I, II and III) of 24 each according to date of birth and body weight at 6 October 1970. The ewe lambs of Groups I and II were shorn on 15 and 30 October, respectively, and Group III acted as unshorn control. The ewe lambs were reared under natural field conditions but supplementary feeding and shelter were provided during the winter months.

A large proportion (94%) of the ewe lambs attained puberty in their first year and differences between the three groups in the number of ewe lambs reaching this stage of development were small and not significant. Autumn shearing of ewe lambs was associated with a very slight but statistically wholly insignificant delay in the mean date of puberty whereas the duration of cyclic activity in these lambs was not affected by such treatments.
Studies on mixtures of dwarf sorghum and beans (Phaseolus vulgaris) with particular reference to plant population
Authors: Osiru D. S. O. , Willey R. W.
Published: March 2009

An experiment is described in which the possible yield benefits of mixing dwarf sorghum and beans were examined under intensive farming conditions. A ‘replacement series’ of pure sorghum, two-thirds sorghum/one-third beans, one-third sorghum/twothirds beans and pure beans was used at four plant populations. A high level of nitrogen was applied to the sorghum to eliminate the effects of nitrogen transfer from the beans.

Yields of the mixtures were up to 55% higher than could be achieved by growing the crops separately. As with some earlier maize/beans experiments (Willey & Osiru, 1972), it is concluded that these yield increases must have been due to a greater utilization of environmental resources. It is suggested that the main factors which made this possible were probably the different rooting depths of the two crops and their different growth cycles.

In agreement with the earlier experiments, mixtures which consisted of two-thirds sorghum/one -third beans gave greatest yield increases at high populations and also had a higher optimum population than the pure stands. However, no such trends were apparent in the mixtures which consisted of one-third sorghum/two-thirds beans.

For both species intra-specific competition was greater than inter-specific competition. In contrast to the earlier maize/beans experiments, the relative interspecific competitive abilities of the species changed with change in the initial proportions of species in the mixtures. In the two-thirds sorghum/one-third beans mixtures the sorghum was the more competitive species, whilst in the one-third sorghum/two-thirds beans mixtures the bean was the more competitive species. Also in contrast to the maize/beans experiments, these relative competitive abilities were not affected by change in theoverall plant population pressure.
A comparative study of the feeding value of dried sugar-beet pulp for milk production
Authors: Castle M. E.
Published: March 2009

Two 16-week experiments with lactating Ayrshire cows were conducted to study the effect on milk production of replacing barley with dried molassed sugar-beet pulp on an equal dry-matter basis. The cows on all treatments received equal weights of hay, groundnut cake and minerals but the contents of barley and of sugar-beet pulp each varied from 0 to 80% in the different concentrate mixtures. The total daily intake of dry matter expressed as a percentage of live weight averaged 2·64 and 2·72 in the two experiments.

The average yield of milk in the two experiments was 18·8 kg/cow per day, and, within each experiment, the mean yields of milk and the contents of solids-not-fat and crude protein were not significantly different on the contrasting feeding treatments. The intake of water was significantly increased as the dried beet pulp replaced the barley but no major changes occurred in the proportions of V.F.A.S in the rumen liquor.

It is concluded that barley and dried molassed sugar-beet pulp had the same feeding value on a dry-matter basis when used in the production ration of milking cows. It is suggested that for most purposes barley and dried sugar-beet pulp are interchangeable on an equal weight basis, but for more precise feeding the two feeds should replace each other on an equal dry-weight basis.
The improvement of bracken dominated hill pasture using herbicides, reseeding, fertilizers and cutting
Authors: Farnworth J. , Davies G. M.
Published: March 2009

Bracken-dominated hill pasture was treated with combinations of bracken and pasture herbicides and two reseeding techniques against a background of fertilization and liming. Picloram and dicamba gave high levels of bracken control and reduced carbohydrate levels in the rhizome. Both paraquat or reseeding with minimal cultivations increased yield of digestible organic matter by reducing competition from native weed grass species and promoting better establishment of ryegrass.
Ruminal digestion of chloroplasts and the protection of protein by glutaraldehyde treatment
Authors: Mangan J. L. , West Janet
Published: March 2009

Chloroplasts, 50–80% intact, were prepared from kale (Brassica oleracea L. var. Marrowstem) by rapid homogenization (3·5 sec) of deveined leaves into partially frozen buffer pH 7·4 made 0·4 M with sucrose, and separated by differential centrifugation. Chloroplasts from 10 kg leaves were administered to the rumen of a sheep and the degradation followed by analysis of the rumen fluid which was collected continuously. Particulate matter of the rumen fluid was separated on discontinuous sucrose density gradients, 8 ml each of 35, 46, 50, 65 and 75% (w/v), centrifuging at 300 g for 1 h at + 2 °C. Chloroplasts were rapidly ingested by entodiniomorphid protozoa and digested with no detectable increase in soluble nitrogen in the rumen fluid. No net production of ammonia occurred but δ-amino-valeric acid increased indicating that amino acid transformations had occurred. Chlorophyll in the ingested chloroplasts was rapidly degraded with a half-life of 50–60 min. In contrast a similar amount of soluble casein added to the rumen degraded with a half-life of 13–14 min with large increase in soluble nitrogen consisting of peptides, amino acids, ammonia and δ-amino-valeric acid. Glutaraldehyde treated chloroplasts were also ingested by protozoa, chlorophyll was rapidly degraded but there was no increase in the soluble nitrogen of the rumen fluid, including ammonia and δ-amino-valeric acid. Water disrupted chloroplasts released soluble protein and in the rumen behaved like casein, producing high proportions of ammonia and δ-amino-valeric acid. The significance of these experiments in the protection of soluble leaf protein from degradation in the rumen of pasture-fed animals is discussed.
A note on the effect of sheep grazing on the yield of grass swards
Authors: Richards I. R. , Wolton K. M. , Ivins J. D.
Published: March 2009

Herbage yield obtained from grass swards is influenced by the presence of grazing animals (Brockman, Rope & Stevens, 1971a, b; Holmes, 1968; Shaw, Brockman & Wolton, 1966). The net effect of grazing in a particular situation depends on the balance between the effects of excretal-N return, which tends to increase yields (Brockman & Wolton, 1963) and those of treading and other sward damage, which tend to reduce yields (Edmond, 1970). This net grazing effect on yield can be measured by comparing yields of cut and grazed swards under management that is in all other respects identical (Shaw et al. 1966). Available data have been examined to obtain quantitative estimates of the net effect of grazing and of the changes in these effects that occur with changes in sward N supply.
Concentrations of intermediate metabolites in the blood and hepatic tissues of pregnant and non-pregnant ewes
Authors: Herriman I. D. , Heitzman R. J. , Priestley I. , Sandhu G. S.
Published: March 2009

Six late pregnant and six non-pregnant Finnish Landrace × Dorset Horn ewes were fed a standard diet. Blood and liver samples were taken and the concentrations of the following metabolites measured: adenine monophosphate (AMP), adenine diphosphate (ADP), adenine triphosphate (ATP), citrate, 2-oxoglutarate, phosphoenol-pyruvate, pyruvate, lactate, 2·phosphoglycerate, 3·phosphoglycerate, malate, β·hydroxybutyrate, acetoacetate, glutamate, alanine, NAD+ and NADH. Comparing non-pregnant with pregnant ewes the liver of the pregnant animals had reduced concentrations of lactate, ADP, NAD+ and NADH, and in the blood there were reductions in lactate, pyruvate, lactate/pyruvate ratio and urea. The concentrations of the other metabolites of the pregnant ewes receiving adequate nutrition were little changed from those of the non-pregnant ewes. The significance of these findings is discussed.
The Journal of Agricultural Science 1905–1980: a historical record
Authors: Bell G. D. H.
Published: March 2009

When I joined the Editorial Board of the Journal in 1949, I regarded the other five members as at least personal acquaintances and some as long-standing friends and colleagues. Indeed, apart from T. H. Middleton, I had known personally all the Editors from the founders in 1905, while my position on the staff of the School of Agriculture at Cambridge since 1931 and my close working association with R. H. Biffen and H. Hunter meant that the Journal occupied a special position in day-to-day life. Service on the Board since 1949 has provided the opportunity for what in effect seems a continuous association over a large part of the Journal's life commencing as it did with R. H. Biffen, A. D. Hall and T. B. Wood, who was the first Chief Editor, succeeded in turn by R. H. Biffen, F. H. A. Marshall, H. Hunter and J. Hammond, all of whom were my senior colleagues.
Concentrations of glucose, albumin, inorganic phosphate and sodium in the blood of beef calves at 2 ½ months of age and their relationships with subsequent weight gain
Authors: Rowlands G. J.
Published: March 2009

Blood samples were taken at 9, 10 and 11 weeks of age from 230 male Hereford × Friesian calves, the progeny of 12 Hereford bulls. Concentrations of blood glucose, serum albumin, inorganic phosphate and sodium were measured and correlated with body weights and growth rates until slaughter at 19½ months of age.

Correlations between growth rates and glucose concentrations (0·44) and between growth rates and albumin concentrations (0·38) were observed until 4 months of age. Similar correlations between body weights and blood glucose or albumin concentrations persisted until 6 months of age. By 10 months, however, the correlations had begun to decline, and by slaughter they had become insignificant.

Correlations between growth rates and inorganic phosphate or sodium concentrations were smaller, and also decreased with age.

The effect of hypoglycaemia on growth rate was compared with the effect of enzootic pneumonia. Although the 10% of calves with the lowest glucose concentrations were growing 24% more slowly than the other calves at the time of sampling, this growth depression was not related to pneumonia, and they subsequently made up for most of the early loss of growth.

Three blood samples were also taken from 22 Hereford bulls. No significant correlations were observed between the blood composition of the bulls and the body weights or weight gains of their progeny.
The use of markers to measure digesta flow from the stomach of sheep fed once daily
Authors: Faichney G. J.
Published: March 2009

Two methods for calculating the flow of digesta and its constituents from the concentrations of two markers, 51Cr-labelled chromium EDTA (51Cr-EDTA) and 103Ru-labelled ruthenium phenanthroline (103Ru-P), and digesta composition were compared in fistulated sheep fed once daily and in other fistulated sheep fed continuously. One method uses the marker concentrations to calculate the flow of whole digesta directly (double-marker) whereas the other uses the markers to calculate separately the flow of fluid and non-filtrable particles, the sum of which is digesta flow (two-marker).

When feed was given continuously, flow values calculated using the double-marker method and the two-marker method, which requires a correction to be made for nonideal behaviour of 51Cr-EDTA, did not differ. When feed was given once daily, the double-marker method consistently overestimated flow relative to the corrected twomarker method but the differences were extremely small (less than 0-8% for digesta flow and 0-5% for nitrogen flow). 51Cr-EDTA as a single marker slightly overestimated digesta flow (up to 2·3%) but grossly overestimated nitrogen flow (up to 22·5%); 103Ru-P as a single marker grossly underestimated both digesta flow (up to 30·5 %) and nitrogen flow (up to 23·1%).

It was concluded that the double-marker method is to be preferred when the diet is given continuously or frequently at fixed intervals. When the diet is given once daily, the two- and double-marker methods can be expected to give similar values. Single markers should not be used for estimating the flow of digesta and its constituents when samples are taken from a simple cannula.
Live-weight, total body-water and maternal body-solid changes in pregnant and lactating beef cows
Authors: Degen A. A. , Young B. A.
Published: March 2009

Live weight and total body water (TBW; measured as tritiated water space) were measured in eight pregnant cross-bred beef cows from the 6th month of gestation to approximately 1 month after calving. Using the values from these measurements and by estimating foetal, foetal fluid and foetal membrane weights from previously established prediction equations, the maternal live weight, maternal body water and maternal body solids were calculated.

Live weight, TBW, maternal body water and maternal live weight increased during gestation, whereas maternal body solids decreased. The TBW percentage of live weight increased from 74·8 to 79·6% during gestation and remained at about 79·5% during the first month of lactation.

It was concluded that live-weight changes alone could be misleading in assessing the energy balance of pregnant ruminants not only because of development of the foetus and associated structures but also because of maternal hydration.
Sorghum-pigeonpea intercropping and the effects of plant population density
Authors: Natarajan M. , Willey R. W.
Published: March 2009

An intercropping experiment is described in which three plant population densities of an early sorghum (82 days) were factorially combined with three plant population densities of a later-maturing pigeonpea (173 days) in a standard 2 sorghum:1 pigeonpea row arrangement. Sorghum growth was not affected by the presence of pigeonpea, and the farmers' primary objective of maintaining a ‘full’ sorghum yield was achieved if the density of the intercropped sorghum was equivalent to the sole crop optimum.

The spatial distribution of roots after 30 and 60 days of growth did not appear to be altered by intercropping, and roots of the two crops were found to intermingle freely.
The effect of chlormequat on the yield and yield components of oil-seed rape
Authors: Scarisbrick D. H. , Daniels R. W. , Rawi A. B. Noor
Published: March 2009

The objective of this study was to examine the effect of the chemical growth regulator chlormequat on the yield and yield components of oil-seed rape. Although this chemical is widely used in wheat production systems, its use as a morpho-regulator for oil-seed rape has not been examined thoroughly. A few Eastern European experiments have been published. Voskerusa (1972) applied it at 2, 4, 6 and 8 kg/ha to winter varieties in Czechoslovakia. His results, which agree with those of Fabry & Hannich (1972), demonstrated reduced winter kill using an autumn application. However, studies on modern varieties such as Rafal, now widely grown in European Economic Community countries, have not been reported in detail.
Sweating response in cattle and its relation to rectal temperature, tolerance of sun and metabolic rate
Authors: Finch Virginia A. , Bennett I. L. , Holmes C. R.
Published: March 2009

Sweating rates were analysed in relation to rectal temperatures of cattle to yield a measure of sweating response within and between animals. The measurements, performed over 36 days, were done in a natural radiant environment on six steers in each of three breeds, Brahman (B), Brahman × Hereford–Shorthorn cross-breds (BX), and Shorthorn (S). Each steer was recorded for 30 min on six occasions randomly distributed among 6 h between 08.00 and 13.00 h, and on six occasions between 11.00 and 16.00 h, all on different days. Sweating response, e.g. the linear slope of the relationship between sweat rate and rectal temperature, was greater for B (294 g/m2. h/°C) than for BX (146 g/m2.h/°C) or S (194 g/m2.h/°C) which did not differ; this helped to explain why the range and mean rectal temperature in B were lower and little affected by environmental heat. Curvilinear models of the sweating response indicated that in the environmental conditions of this study, the limit of sweating for B and BX was not reached, while for S, the sweating response approached a plateau. Between animals, the relationship of sweating response to mean rectal temperature was negative (P < 0·01) and its relationship to the time spent in the sun at pasture positive (P < 0·025). Thus this measure of sweating response was a good indicator of thermoregulatory ability of the cattle. However, the sweating response of the steers did not relate to their grazing time or growth. The reasons for this are discussed. Finally, the sweating response was found to be negatively correlated with metabolic rate between animals within breeds (P < 0·01) and this suggested that it may be difficult to combine the desirable traits of good heat adaptation and high metabolic potential in cattle.
Carcass weight as an index of carcass components with particular reference to fat
Authors: Barton R. A. , Kirton A. H.
Published: March 2009

In many animal production experiments, carcass weight is used as the sole criterion for the effectiveness of the treatments and of the nutritional status of the animals involved. In these experiments some knowledge of the carcass components would be desirable in order to assess any effects on the various tissues. Determination of these components has hitherto been costly and time consuming. Accordingly, these disadvantages have lead to a search for simple indices of carcass composition which can be readily applied even in relatively large-scale experiments. Until recently, however, no research worker has specified a relationship between carcass weight and carcass composition which would justify the use of carcass weight alone. There are, of course, many indications which suggest that such a relationship would exist, at least, for the main tissues of the carcass.
Growth of spring barley under drought: crop development, photosynthesis, dry-matter accumulation and nutrient content
Authors: Lawlor D. W. , Day W. , Johnston A. E. , Legg B. J. , Parkinson K. J.
Published: March 2009

The effects of water deficit on growth of spring barley were analysed under five irrigation treatments. One crop was irrigated at weekly intervals from emergence throughout the growing season, and one was not irrigated at all after emergence. Soil water deficits in the other treatments were allowed to develop early, intermediate or late in the crop's development.

Weekly irrigation produced a crop with a large leaf area index (maximum value 4) and maintained green leaf and awns throughout the grain-filling period. Early drought decreased leaf area index (maximum value 2) by slowing expansion of main-stem leaves and decreasing the number and growth of tiller leaves. Leaf senescence was also increased with drought. Drought late in the development of ears and leaves and during the grain-filling period caused leaves and awns to senesce so that the total photosynthetic areas decreased faster than with irrigation. Photosynthetic rate per unit leaf area was little affected by drought so total dry-matter production was most affected by differences in leaf area.

Early drought gave fewer tillers (550/m2) and fewer grains per ear (18) than did irrigation (760 tillers/m2 and 21 grains per ear). Late irrigation after drought increased the number of grains per ear slightly but not the number of ears/m2. Thus at the start of the grain-filling period crops which had suffered drought early had fewer grains than irrigated (9·5 and 18·8 × 103/m2 respectively) or crops which suffered drought later in development (14 × 103/m2).

During the first 2 weeks of filling, grains grew at almost the same rate in all treatments. Current assimilate supply was probably insufficient to provide this growth in crops which had suffered drought, and stem reserves were mobilized, as shown by the decrease in stem mass during the period. Grains filled for 8 days longer with irrigation and were heavier (36–38 mg) than without irrigation (29–30 mg). Drought throughout the grainfilling period after irrigation earlier in the season resulted in the smallest grains (29 mg).

Grain yield depended on the number of ears, the number of grains per ear and mass per grain. Early drought decreased tillering and tiller ear production and the number of grains that filled in each ear. Late drought affected grain size via the effects on photosynthetic surface area.

Drought decreased the concentrations of phosphorus, potassium and magnesium in the dry matter of crops, and irrigation after drought increased them. Concentration of nitrogen was little affected by treatment. Possible mechanisms by which water deficits and nutrient supply affect crop growth and yield are discussed.
Effect of type of intravaginal progestagen on the outcome of fixed-time artificial insemination
Authors: Smith P. A. , Boland M. P. , Gordon I.
Published: March 2009

It is now possible to synchronize the cycle of ewes at all times of the year (Gordon, 1975). Conception rates approaching those obtained following natural service have been reported following double (Colas & Brice, 1970; Colas et al. 1973; Barlow, Pryce-Jones & Reed, 1974; Gordon, 1975) or single (Smith, Boland & Gordon, 1978) set-time inseminations. In France, synchronization of ewes' oestrous cycle is based on the use of a Cronolone pessary (Colas, 1975), while field trials conducted in Britain have used the 60 mg Medroxy progesterone acetate (MAP) sponge (Barlow et al. 1974). Robinson et al. (1967) in an evaluation of different progestagen treatments found MAP to be less predictable than Cronolone. The purpose of the present experiment therefore was to evaluate the use of a 30 mg Cronolone or a 60 mg MAP intravaginal treatment when used in conjunction with fixed-time inseminations. In addition, two dose levels of pregnant mare serum gonadotrophin (PMSG) were compared.
Changes in magnesium and calcium in soils of the Broadbalk wheat experiment at Rothamsted from 1865 to 1966
Authors: Bolton J.
Published: March 2009

Chalk in the 0–9 in topsoil of Broadbalk has declined from nearly 5% in 1865 to less than 1 % in some plots in 1966, and fastest in plots given ammonium sulphate. Losses were equivalent to 5–8 cwt limestone/acre annually. The paper relates these rates to estimated anion losses, especially bicarbonate, from the plots. Af-ammonium acetate dissolved Ca and Mg from chalk particles in the soils. After correcting for this, exchangeable magnesium had increased during the first 50 years but decreased since 1914 in the F.Y.M. plot. In plots given none or 10 lb/acre of magnesium in fertilizer annually, exchangeable magnesium had changed little since 1865. Thissuggests that equilibrium was soon established between additions and losses of Mg in all except the F.Y.M. plots. Estimates of annual additions and losses of Mg from each plot show that an equilibrium is feasible without large gains from non-exchangeable soil resources. A method of calculating losses of Mg in the drainage using activity ratios and annual calcium losses was developed.
The accuracy of a range of capacitance probe methods for estimating pasture yields
Authors: Johns G. G.
Published: March 2009

Nine different capacitance probe methods were used to estimate the herbage yields of 32 small pasture plots; ten meter readings were used in conjunction with the yield data from a variable number (n) of quadrats in each plot. Expected yields were determined by cutting ten quadrats per plot. Estimated yields were compared with expected yields for both the differing methods and the differing values of n. At each level of n the yield estimates from the different probe methods were compared with those obtained simply by cutting n quadrats.

Using calibration data from only one quadrat per plot (n = 1), all probe methods except one gave greater accuracy than that obtained from the single quadrat yields only. For n = 2, the advantage of the probe methods was less pronounced and where n = 3 only one probe method (one which involved no regression computations) gave superior accuracy to that obtained merely by using the yield data from the three cut quadrats. At n > 3, only the one probe method gave increased precision; all other probe methods were markedly less accurate than the equivalent raw quadrat results.

Only one probe technique (which combined data from markedly dissimilar swards) gave yield estimates which were noticeably biased.

Results from an earlier study are presented to demonstrate the influence of season, species and irrigation on probe calibration.

Recommendations are made on the various probe methods which may prove effective in some experimental situations.
An analysis of the relationship between potential evaporation and dry-matter accumulation for winter wheat
Authors: Green C. F. , Vaidyanathan L. V. , Hough M. N.
Published: March 2009

Sequential dry-matter measurements for winter wheat crops grown at different sites during different seasons were plotted against accumulated potential evaporation. A relation consisting of two intersecting straight lines represented the observations. Early crop growth had a gentle slope due to an incomplete leaf canopy. Later growth occurred at a rate which depended upon the amount of applied nitrogen, the amount of radiation and the availability of water. The intersection occurred consistently at a leaf area index of 1·25.