bluuebunny/crossref_metadata_2025 huggingface dataset:
Rumen degradation of the main forage species harvested from permanent mountain meadows in North-western Spain
Authors: Lopez S. , Carro M. D. , Gonzalez J. S. , Ovejero F. J.
Published: March 2009

Herbage samples were collected in late June, and again in early September (1987) from permanent mountain meadows situated in North-western Spain (León). Botanical composition was determined by grouping the species into grasses, legumes and herbaceous ‘weeds’. Rumen degradability of the dry matter (DM), crude protein (CP) and neutral detergent fibre (NDF) of the botanical groups in each harvest season was determined by the nylon-bag technique.

Grasses and legumes differed in their degradation characteristics, and the comparisons between forage species were different for the two harvest seasons. There were no significant differences between September grasses, June legumes and September legumes in the potential degradabilities of the DM (86·9, 87·1 and 88·4%) and CP (94·2, 92·4 and 93·8%). The NDF of grasses harvested in September was degraded to a greater extent (80·6%) than that of legumes from both harvests (70·9 and 73·6% in June and September respectively). However, June grasses showed significantly lower potential degradabilities for the DM (77·0 %), CP (84·3%) and cell wall (65·9%). Legumes were degraded at a faster rate than grasses (mean DM degradation rates of 0·143 and 0·057 respectively), and lag times were longer for grasses (4·7 h) than for legumes (2·5 h). Rumen degradation characteristics of the herbaceous ‘weeds’ were estimated, but it should be remembered that many other factors may limit their utilization by ruminants.

It was concluded that the major constraint to the nutritive value of these permanent swards would be the maturity of the grasses harvested in June, which markedly reduced the rumen degradability of the forages.
Effects of herbicide use, fungicide use and position in the field on the yield and yield components of spring barley
Authors: Boatman N. D.
Published: March 2009

Six experiments were carried out over 2 years (1985 and 1986) in commercial spring barley crops on calcareous soils in Hampshire. Herbicides increased grain yield by 0·05–1·21 t/ha, and fungicides by 0·01–0·68 t/ha. Herbicide use affected each of the yield components ears/plant, grains/ear, 1000-grain weight and harvest index in one or more cases but the effects were not consistent between experiments or consistently related to yield increases. Fungicide use had little effect on yield components other than 1000-grain weight, which was significantly increased in all experiments. There were no significant herbicide × fungicide interactions. Large differences in yield were recorded between field edge (headland) and midfield plots, with headland plots outyielding the midfield in two of the three experiments where this effect was considered.

The effects of fungicide use were accounted for by associated increases in the green lamina area of the flag leaf and second leaf at the late milk stage of grain development. This is consistent with previous work. Differences in yield response to herbicide between sites were linearly related both to weed numbers early in the season and to weed biomass at harvest. Weeds did not always directly replace crop biomass; in some experiments the combined dry matter production was greater when herbicide was not used. However, the results indicate that, where a diverse weed flora composed of species of moderate to low competitive ability is present, simple weed counts may provide a useful indication of potential yield loss.

It is concluded that headland areas can often be as productive as the rest of the field, but a greater understanding of the factors involved is needed if this potential is to be realized.
Comparisons of farmyard manure, sewage sludge, and other organic manures tested on potatoes and a succeeding cereal crop at Rothamsted
Authors: Garner H. V.
Published: March 2009

Field experiments were done at Rothamsted each year from 1940 to 1948 to compare arange of organic manures with farmyard manure and with fertilizers. Eight kinds of farmyard manure (FYM) made under controlled conditions from the same quantity of feedingstuffs, sewage sludges from 7 sources, composts of sewage sludge with straw from 4 sources, 5 types of town refuse, cut-bracken stacked over winter, and peat, were tested on potatoes at single and double dressings. All organic manures were compared with and without fertilizers supplying 0.6 cwt. N, 0.6 cwt.P2O5and 1.0 cwt. K2O. The soils were heavy loams, farmed in normal rotations; a fresh field was used each year. Residual effects were measured on cereals grown in the year after the potatoes.
The control of potato pale cyst-nematode (Globodera pallida) by chemical and cultural methods in different soils
Authors: Whitehead A. G. , Nichols A. J. F. , Senior J. C.
Published: March 2009

In 12 field experiments in England (1985, 1991 and 1992), on soils infested with potato pale cystnematode (Globodera pallida), oxamyl increased yields of susceptible and partially-resistant potatoes and lessened nematode multiplication at some sites but not others. Attempts to explain these site differences were unsuccessful. In a heavily infested peaty loam, large amounts of aldicarb or oxamyl, smaller amounts of both conjointly or 6·8 kg oxamyl/ha incorporated in the top 10 cm of the soil were needed to prevent G. pallida multiplication on susceptible Wilja potatoes. In three experiments, 1,3-dichloropropene at 250 or 225 1/ha increased tuber yields more than oxamyl did but had little or no effect on G. pallida multiplication. Ethoprophos at 11 kg/ha or fosthiezate at 4 kg/ha lessened G. pallida multiplication on Désirée potatoes in a silt loam soil but not in a peaty loam soil.

The multiplication of G. pallida was reliably controlled in ten experiments by partially-resistant Morag or Santé potatoes. Soil population densities of G. pallida were greatly decreased by one or two crops of Cara potatoes uprooted when the first female nematodes were visible on the roots.

It is concluded that granular nematicides and 1,3-dichloropropene are best employed to lessen injury to susceptible and partially-resistant potatoes and that G. pallida increase is best controlled by partially-resistant potatoes protected by a nematicide. Soil infestation levels can be decreased rapidly by soil fumigation or trap cropping with Cara potatoes.
Effect of variation in density and phosphate supply on seed production of Stylosanthes humilis
Authors: Shelton H. M. , Humphreys L. R.
Published: March 2009

Stylosanthes humilis was grown at Brisbane at densities of 10, 50, 250, 850 and 3800 plants/m2 in boxes of sand which received basal nutrients, applications of 0, 10 and 50 kg P/ha as calcium dihydrogen phosphate, and frequent irrigation.

Maximum seed yield was 69 g/m2 at a density of 850 plants/m2. Seed yield was linearly related to the logarithm of density up to 250 plants/m2, and was comparatively stable over the upper density range, declining slightly at supra-optimal density. Inflorescence density exerted the primary control over seed yield, but seed set per floret and floret number per inflorescence were also influential.

The application of 50 kg P/ha increased yield of plant tops by 54% and seed yield by 20%.
An evaluation of Merino wool quality:IV. The classification of fibres according to follicle type
Authors: Gallagher J. R.
Published: March 2009

Histological sections of skin samples from two Merino flocks were studied to determine if coarse fibres were from primary (P) or secondary (S) follicles.

The mean fibre diameters of P and S fibres were 23.7 and 19.7 µ respectively in flock 1 (significantly different P < 0.5) and 23.1 and 20.5 µ respectively in flock 2 (not significantly different).

The percentages of fibres exceeding 30 µ in flock 1 were 10.1% P and 1.0% S. In flock 2, the percentages of fibres exceeding 30 µ were 10.3% P and 0.6% S fibres. If 30 µ is taken as an arbitrary level of fibre fineness, then the majority of coarse fibres wore from P follicles.

The observed S/P ratios were 22.8/1 at 16 months on flock 1 and 21.7/1 at 15 months in flock 2.
The concentration of minerals in the blood of genetically diverse groups of sheep:V. Concentrations of copper, calcium, phosphorus, magnesium, potassium, and sodium in the blood of lambs and ewes
Authors: Wiener Gerald , Field A. C.
Published: March 2009

Concentrations of Cu, Ca, P, Mg, K and Na were examined in the blood plasma (whole blood for P) of 149 adult ewes and their 244, 15-week-old lambs in a grassland flock of sheep. The ewes were 3 or 4 years old and of five crossbred types produced by mating Scottish Blackface females to Border Leicester, dun Forest, Dorset Horn, Finnish Landrace and Tasmanian Merino rams. The lambs in turn were the offspring of these crossbred ewes, and two rams of each of the Oxford Down, Southdown, Soay breeds and one Cheviot ram.

Breed of sire (but not sire within breed) was a significant source of variation in the concentration of all the minerals, except Na, in the blood of both ewes and lambs. Other factors considered were age of ewe and sex, birth type, type of rearing, and date of birth of lamb. None of these appeared to be significant sources of variation except that twins and triplets, if reared as such, had higher concentrations of Ca in their blood than lambs born and reared as singles; however the ewes with singles were on different pasture from those rearing 2–3 lambs. For the mineral levels in the blood of the lambs there was no significant interaction of breed of ram with cross-breed of ewe. The lambs had substantially higher concentrations of Cu and P in their blood than their mothers and also significantly higher concentrations of Ca, Mg and possibly K. This may not be attributable to age alone because the lambs and their mothers also differed in genotype.

Heritability estimates based on parent-offspring regression were 0·4 ±0·14 for Cu and less than 0·2 for the other minerals.
Effect of weaning on the capacity of pig intestinal villi to digest and absorb nutrients
Authors: Miller B. G. , James P. S. , Smith M. W. , Bourne F. J.
Published: March 2009

A comprehensive study of how age and weaning affect intestinal structure and enterocyte ability to digest and absorb nutrients has been carried out in 4- and 6-week-old piglets.

Villus length, which did not change significantly in unweaned piglets 4–6 weeks after birth, was halved 5 days after weaning. Crypt depth, which increased normally in unweaned piglets, is further increased by weaning in both 4- and 6-week-old animals.

Lactase activity, which decreased normally with age, was inhibited more than a-glucosidase by weaning. Weaning of 6-week-old piglets also caused a significant increase in maltase II and III activities. Alkaline phosphatase activity was unaffected by age or weaning in 4- and 6-week-old piglet intestine.

Na-dependent alanine transport was reduced in 6- compared with 4-week-old unweaned piglet intestine. Weaning inhibited Na-dependent alanine transport in 4- but not 6-week-old pigs. Na-independent alanine transport, which was considerably less than that found in the presence of Na, was not noticeably affected by age or weaning.

Weaning-induced problems in intestinal function appear from the present results to be caused more by changes in intestinal structure and specific loss of digestive enzymes rather than by any gross change in absorptive function. The possible role of immune as well as nutritional factors in causing these weaning-dependent changes in intestinal function is discussed.
Nitrogen relationships and residual effects of intercropping sorghum with legumes
Authors: Bandyopadhyay S. K. , De R.
Published: March 2009

Intercropped with legumes, sorghum removed more N from the growing medium than when grown alone. 16N data showed that out of the total N removed by sorghum in a sorghum + mung mixture 18·1% was derived from the fertilizer urea and 81·9% came from the soil pool; the latter included 21·9 % N derived from current fixation by the legumes. When grown alone sorghum plants derived 18·6 % N from urea and 81·4 % from the soil.

The yield of wheat grown in sequence was 5·13 t/ha after a previous sole crop of mung and 3·47 t/ha after sorghum. The yield of wheat after sole crops of legume was greater than after their mixture with sorghum. The latter was, however, greater than its yield after sole sorghum.

The economic optimum rate of N required after wheat, computed from an experiment with several rates of applied N on an adjacent plot, was 124 and 105 kg N/ha at expected yields of 5·2 and 4·5 t/ha of wheat respectively. By interpolation the relative yield advantage from sole legumes ranged between 28 and 68 kg N/ha in 1982–3 and was more than 90 kg N/ha in the next year. These advantages from legume + non-legume mixtures equalled 12–17 kg N/ha applied to wheat, in addition to 50 kg N/ha applied uniformly to the sequential crop of wheat.
A survey of ryegrass endophyte (Acremonium loliae) in the U.K. and its apparent ineffectually on a seedling pest
Authors: Lewis G. C. , Clements R. O.
Published: March 2009

Acremonium loliaeis an endophytic fungus which infects plants of perennial ryegrass (Lolium perenne), an important pasture grass in New Zealand and much of Western Europe. In New Zealand the endophyte–ryegrass association was found recently to give rise to tremorgenic substances (lolitrem A and B), which are the cause of a serious disorder of grazing and domestic livestock there. The endophyte also confers resistance in ryegrass plants to certain insect pests in New Zealand and enhances plant growth even in the absence of pests. In the present work 61 swards at 52 widespread sites in the U.K. were checked for the presence of endophyte mycelium, and it was found in 14 swards, of which 12 were at least 15 years old. ELISA (enzyme-linked immunosorbent assay) tests confirmed that the fungus wasA. loliae.Also, lolitrem B was detected in plants from most of the sites where the mycelium was found; this appears to be the first time this tremorgen has been reported in the U.K. or perhaps in Europe. In a small-plot experiment at two sites with newly sown perennial ryegrass the endophyte appeared to have no effect on infestation by frit fly larvae, a major pest of seedling ryegrass plants. Also, in the present work, the endophyte had no measurable effect on the growth or overwinter mortality of larvae.
The effects of frequency of cutting and nitrogen application rates on the yields from perennial ryegrass plus white clover swards
Authors: Reid D.
Published: March 2009

The results are presented for a 4-year experiment in which three cutting frequency treatments and four nitrogen fertilizer rates were applied on plots sown with perennial ryegrass and one of three varieties of white clover. The cutting frequencies were three, five and tencuts each year, and the nitrogen rates were 0, 150, 300 and 450 kg/ha annually. Two medium-large leaf clover varieties Blanca and Sabeda were compared with the medium-small leaf Aberystwyth S. 100. Comparison of the present results with those from an earlier experiment (Reid, 1978) suggests that, on average over the clover varieties, the inclusion of white clover in the ryegrass sward results in smaller effects of nitrogen application rate and cutting frequency. Decreasing the number of cuts from ten to five gave a marked increase in the dry-matter yield of mixed herbage and of clover at all nitrogen rates, but the decrease from five to three cuts had little additional effect. These results suggest that white clover may be more suited to conservation systems than previously thought, but for optimum production the interval between cuts should not exceed about 5 weeks. The medium-large leaf varieties of white clover did not appear to be in any way superior to the medium-small leaf varieties for conservation systems.
Effect of shearing on oestrus and ovulation in sheep
Authors: Parr R. A. , Davis I. F. , Tilbrook A. J.
Published: March 2009

Shearing causes a rapid increase in plasma cortisol concentrations (Kilgour & de Langen 1970; Purchas 1973; Fulkerson & Jamieson 1982), indicating that acute physiological responses are associated with the procedure. Environmental stress before mating can result in a delay in the onset of oestrus (Doney et al. 1973) and a reduction in ovulation rates (Doney et al. 1976). Dobson (1988) demonstrated that shearing caused a reduction in the luteinizing hormone (LH) response to exogenous gonadotrophin releasing hormone (GnRH) in anoestrous ewes. Such a response to shearing could influence the incidence of oestrus and ovulation.
Studies on the establishment of white-flowered faba bean (Vicia faba)
Authors: Kantar F. , Hebblethwaite P. D. , Pilbeam J.
Published: March 2009

Early reports on new, nutritionally superior, white-flowered (zero-tannin) faba bean cultivars indicated that they may show poor emergence under field conditions. The field emergence of 23 winter and spring type white and coloured-flowered lines and cultivars was investigated in relation to fungicidal seed dressing in 1989/1990 and 1990/1991 in the UK. These trials showed no definite emergence problems in white-flowered faba beans, probably because of favourable soil and weather conditions. Further experiments were therefore conducted in relation to emergence under controlled environmental conditions. The emergence of lines near-isogenic except for flower colour (the coloured line SCI v. the white line SWI) was investigated in relation to a range of soil moisture levels (soil water potential (SWP) ranging from −1·02 to 0·0 MPa (waterlogged)) and to three temperatures (22, 12 and 5°C) in a clay loam soil. Emergence was rapid and high at the SWP range from −0·52 to −0·24 MPa in both lines, depending on temperature. Any decrease or increase in SWP beyond this range resulted in a substantial reduction and delay in emergence in both lines. Emergence of SWI was more adversely affected than SCI when the temperature decreased from 22 to 5 °C. The emergence of six winter and six spring lines/cultivars was tested in relation to fungicidal seed dressing using wet soil (-0·06 MPa) at 5 °C under controlled environmental conditions. White-flowered winter lines (WWI, Polar and WD) and the spring line, SWI, had poor emergence (56–85%) compared to coloured types (86–98%). In some lines there was a slight improvement when using a fungicidal seed dressing.
Effect of rates and timing of nitrogen fertilizer on the grain protein content of wheat (Triticum aestivum), grown in two contrasting seasons in South East England
Authors: Sajo A. A. , Scarisbrick D. H. , Clewer A. G.
Published: March 2009

A field experiment was carried out at the Wye College Farm during 1988 and 1989. The aim was to study the effects of three rates and timings of nitrogen fertilizer application on the grain protein content of spring wheat cv. Axona. Results demonstrated that timing of fertilizer application was more important than the rate of nitrogen used. Grain protein development and final grain protein contents are discussed in relation to the seasonal variations experienced during the 1988 and 1989 growing seasons in South East England. Due to the early February sowing in 1989, grain protein content was not affected by the summer drought. Thus, the advantage of early sowing of spring wheat to reduce the detrimental effect of early summer drought on the grain protein content is emphasised.
Glomus intraradixeffects on citrus rootstock seedling growth in various potting media
Authors: Nemec S.
Published: March 2009

Five potting media components mixed in various combinations and in various percentages of one with another (0, 14·3, 29, 42, 57, 71 and 100% by volume of the second component with the first) were inoculated withGlomus intraradixin six experiments. Seedlings of citrus rootstocks were grown from seed in these mixes. Sour orange in inoculated peat plus vermiculite, Astatula fine sand plus vermiculite, and peat plus Perlite® in all percentage combinations grewc.two- to threefold taller than noninoculated control plants. Up to twofold growth increases of sour orange occurred in vermiculite amended with wood shavings. The best evidence for fungus-mediated plant growth occurred in Astatula fine sand amended with 29–71% Perlite, and the roots in that combination had the highest percentage of infection. In another experiment in which Astatula fine sand was amended with up to 16% of an acid peat, ratios of inoculated rough lemon plant growth to controls decreased as the peat content in the medium increased. Top and root weight ratios of inoculated:control seedlings in the six experiments did not fit four simple linear models.
Influence of production and storage conditions on subsequent growth and tuber yield of potato (Solanum spp.) in the hot tropics
Authors: Midmore D. J. , Roca J.
Published: March 2009

A series of experiments to quantify the response of diverse potato genotypes to production and storage conditions in hot climates was carried out in 1984–87 at three sites in Peru, two of which were characterized by at least one hot season per year. Yield stability and field performance of seed tubers of six clones produced in situ, and stored in diffused light (DLS) or cold stored (CS), were compared with those of good quality seed tubers produced and stored in cool conditions. The yield potential of tubers produced in hot climates and grown as (i) a double crop per year with short DLS (1–4 months) (ii) a single crop per year with long DLS (c. 8 months) and (iii) a single crop per year with long CS (c. 8 months) was compared with that of seed tubers produced in cool conditions and introduced in successive crops.

The first replanting of tubers produced in hot climates resulted in lower yield than that of coolproduced tubers. Yield reductions in clones ranged from 30 to 93% when replanted within 4 months, from 10 to 100% when replanted after 7–10·5 months of DLS and from 0 to 82% after similar periods of CS. Reduced yield was often due to poor plant vigour and crop growth leading to inefficient interception of solar radiation. There was, however, no evidence that the efficiency of utilization of intercepted radiation for tuber dry matter production was influenced by storage treatment. Poor sprout growth at planting reduced yield considerably for late clones in double cropping. Low dry matter content of tubers produced in hot climates did not influence emergence rate, but was related to poor plant vigour in the first replant under warmer conditions. Replanting and storage in hot climates did not enhance the initial reduction of tuber dry matter, which was evident after the first hot season. Tuber yields continued to decline, particularly under single cropping with long DLS.

For the clones studied, CS would be a feasible storage method for potato production in hot climates if replanted tubers were used on an annual basis. For double cropping, short dormancy is essential; however, poor plant vigour results in additional yield reductions. Our data indicate that clonal selection for maximum production in hot climates should take into account the proposed or existing production and storage schemes.
Short-term undernutrition and prenatal mortality in young and mature Merino ewes
Authors: Mackenzie A. J. , Edey T. N.
Published: March 2009

Prenatal mortality was examined in 74 primiparous Merino ewes which, after hand mating to fertile rams on the second oestrus following synchronization, were allocated to two groups. One group of 38 ewes was confined to yards and restricted to approximately 30% of their maintenance requirement for 14 days while the other group of 36 remained at pasture. The degree and timing of prenatal loss was assessed by corpora lutea counts, pregnancy diagnosis about day 40, returns to service and lambing records.

The mean ovulation rate was 1·06 and the 19-day non-return rate was 87·8%. Pregnancy failed in a higher proportion of the underfed ewes (45·0%) than in the control ewes (30·8%) but this difference did not reach significance. Of the ewes returning to service, significantly more did so with cycles longer than 19 days in the underfed group (9/12) than in the control group (2/8), indicating that in the latter stages, the treatment may have been detrimental to embryo survival.

In a second experiment, ovulation rate and prenatal mortality, assessed as in the first experiment, were studied in 85 mature Merino ewes subjected to the following nutritional treatments: HH, control; HL, 30% submaintenance feeding for 14 days following mating; LH, 15% submaintenance feeding for 7 days prior to mating; LL, both submaintenance treatments.

Acute undernutrition prior to mating (LH) had no effect on ovulation rate or prenatal mortality. Ovulation rates were low over all groups (mean 1·09) and thus precluded any valid examination of ovulation rate and body weight relationships. The right ovary was significantly more active in producing ova than the left in all groups (P < 0·05). Although ova wastage was apparently higher in. the post-mating undernutrition groups (HL, 44%; LL, 48%; LH, 50%) than in the control group (HH, 35%), the differences were not significant. An increased incidence of extended (> 19 days) first-return cycle lengths in group LL provided some evidence of induced prenatal mortality.

In so far as the experiments can be considered together, they indicate that if body weights are comparable, primiparous 1½-year-old ewes are not necessarily more susceptible than mature ewes to prenatal mortality induced by severe short-term undernutrition.
Water-soluble, exchangeable and nonexchangeable potassium in six soil series from tropical India
Authors: Rao A. Subba , Sekhon G. S.
Published: March 2009

Six soil series differed in water-soluble, exchangeable and nonexchangeable K. Significant positive relationships were observed between exchangeable K and water-soluble K. A highly significant positive relationship was found between the K saturation of the cation exchange complex and water-soluble K in the individual soil series, and when the six series were pooled; K saturation, therefore, may predict water-soluble K in a range of tropical soils. Potassium desorbed in 35 min by electroultrafiltration (EUF) may serve as a measure of exchangeable K in predominantly kaolinitic tropical soils. In soils with appreciable amounts of mica, longer K extraction by EUF (up to 70 min) may indicate the reserves of nonexchangeable K.
Growth of lambs offered fixed amounts of roughage and concentrate either simultaneously, progressively or separately
Authors: Wilkinson R. G. , Greenhalgh J. F. D.
Published: March 2009

Two experiments were carried out to study the efficiency of energy utilization by Suffolk × Blackface lambs. In the first experiment, a digestibility trial, the lambs were fed on either a roughage (chopped dried grass), concentrate (whole barley, ground barley and fishmeal), or mixed (roughage and concentrate) diet. The dry matter (DM) and organic matter digestibility coefficients of the mixed diet were slightly, but not significantly, lower than the ‘expected’ values calculated by summation of the separately determined digestibility coefficients of the component feeds. Similarly, the metabolizable energy (ME) value was 1·6% lower than the ‘expected’ value.

In the second experiment, lambs were offered 52·5 kg roughage DM (ME 9·96 MJ/kg DM) and 52·5 kg concentrate DM (ME 11·59 MJ/kg DM) as:(i) a mixed diet (M); (ii) a progressive change from roughage to concentrate (R–C); (iii) a progressive change from concentrate to roughage (C–R); or 105 kg roughage or concentrate DM as either (iv) a roughage diet (R), or (v) a concentrate diet (C). Lambs on treatments R–C, C–R and R and C combined took a similar time to consume their allocation of food and achieved a similar final empty body weight (EBW) and empty body composition. In addition, the total energy retention (ER) of lambs on these treatments was similar to that predicted by a feeding standards model for lambs of a similar liveweight offered diets of the same ME content. Lambs on treatment M consumed their allocation of food faster than those on all other treatments and achieved a slightly, but not significantly, higher final EBW, which contained a higher proportion of fat. The ER was higher than predicted. The higher overall efficiency of lambs on treatment M was attributed to higher daily intakes and differences in the ratio of protein: fat deposited and maintained by lambs on each treatment. The adoption of separate efficiency constants for both deposition and maintenance of protein and fat in current feeding standards would result in a more accurate prediction of animal performance.
Potential nutritive value of a wide range of grassland species
Authors: Wilman D. , Riley J. A.
Published: March 2009

Fifteen grassland species were grown in a heated glasshouse in February-April 1985. The harvested herbage was separated into leaf and ‘stem’ and analysed for neutral detergent fibre, digestibility, physical breakdown when macerated, fibrosity, water soluble carbohydrate and N, P, K, Ca, Mg and Na.

Lolium perenne was digestible, but rather high in neutral detergent fibre and not readily broken down by maceration. The other grasses tested, Holcus lanatus, Poa annua and Glyceria fluitans, tended to be less digestible and higher in neutral detergent fibre than L. perenne.

The leaves of all 11 dicotyledonous species were much lower in neutral detergent fibre than the leaves of the grasses, and most broke down readily when macerated. The stems of Medicago saliva and of two shrub species (Lonicera periclymenum and Prunus spinosa) were the highest in neutral detergent fibre.

Rumex obtusifolius, Spergula arvensis and Stellaria media were high in Mg; Plantago lanceolata, S. arvensis and S. media were high in Na; and S. arvensis was high in P.

Three perennial and two annual herbaceous, dicotyledonous non-legumes were selected as being of sufficient promise and interest to be compared with Lolium perenne in feeding experiments: Plantago lanceolata, Taraxacum officinale, Rumex obtusifolius, Spergula arvensis and Stellaria media.
Termination of flowering in ‘indeterminate’ faba beans (Vicia faba)
Authors: Stoddard F. L.
Published: March 2009

The duration of flowering was investigated in 14 accessions of indeterminate faba (field) beans (Vicia faba L.) planted near Adelaide, South Australia in 1986 and 1987. All flowers and young pods were removed from plants at 4–7 day intervals. Plants of ‘Mediterranean’ origin produced 20–30 flowering nodes while those of European ‘spring bean’ type produced up to 50. Terminal inflorescences were eventually produced in all accessions. In control plants, the number of days between anthesis at successive nodes was partly dependent on nocturnal minimum temperature and varied very little between genotypes. It should be possible to make best use of the growing season by optimizing the potential production of nodes, but there is little opportunity for manipulating the rate of their appearance.
Physical characteristics of the alimentary tract in relation to seasonal changes in voluntary food intake by the red deer (Cervus elaphus)
Authors: Sibbald A. M. , Milne J. A.
Published: March 2009

Voluntary intakes of a medium-quality grass hay were measured in winter (early January) and in spring (late April) near Edinburgh for two separate groups of six red deer, together with digestibility and mean retention times of the particulate-phase marker, 103Ru-phenanthroline. The deer were then slaughtered and the weights of digesta and the dimensions of the alimentary tract were measured. Voluntary intakes of dry matter were significantly higher in spring than in winter, but there was no difference in digestibility or mean retention time of 103Ru-phenanthroline. There were no significant differences in any of the organ weights or the dimensions of the intestines between the groups slaughtered in winter and spring. Dry matter proportions of digesta in the rumen, abomasum, small intestine and caecum, the wet and dry weights of rumen digesta and the water-filled capacity of the rumen were significantly greater in spring.
Use of prolonged-release bovine somatotropin for milk production in British Friesian dairy cows. 1. Effect on intake, milk production and feed efficiency in two consecutive lactations of treatment
Authors: Phipps R. H. , Weller R. F. , Craven N. , Peel C. J.
Published: March 2009

In two consecutive lactations in 1985/86 and 1986/87, 60 cows were injected with 500 mg of Sometribove, methionyl bovine somatotropin (BST), or a placebo at day 60±3 post partum; injections were repeated fortnightly for the remainder of each lactation. All cows received the same complete diet (metabolizable energy (ME) 11·5 MJ/kg dry matter; crude protein 169 g/kg dry matter) ad libitum for the first 20 weeks of lactation, after which, energy concentration of the diet was reduced as yield declined.

The administration of BST significantly increased milk yield by 4·3 (P < 0·001) and 3·1 kg/day (P < 0·05) in the first and second lactations, respectively. The mean dry matter (DM) intake of 16·3 kg/day in lactation 1 for the treated group was significantly (P < 0·01) higher than the 14·7 kg/day recorded for the control group. The response in intake was not significant until 6 weeks after treatment started. However, in the pretreatment period of the subseque1t lactation, the DM intake of the cows in the treated group was already significantly (P < 0·01) higher (+ 1·2 kg/day) than that of the control group. Although the DM intake in the treatment period of lactation 2 was also higher for the treated group, the difference from the control group was not significant.

With the exception of a significant (P < 0·01) increase in milk protein (control 35·3 g/kg v. treated 36·3 g/kg) in lactation 1, overall milk composition was unaffected by BST treatment. The administration of BST increased apparent feed efficiency (kg 4% fat-corrected milk (FCM)/kg DM intake) by 6 and 10% and gross feed efficiency (kg FCM/MJ ME) by 8 and 6% in lactations 1 and 2, respectively.

Animals treated with BST had significantly (P < 0·05) lower scores for body condition during the treatment period in lactation 1. This was, however, recouped during the dry period so that both groups had similar body conditions before the start of the next treatment period.

BST administered every 14 days in a prolonged-release formulation increased the yields of milk and milk constituents and apparent and gross feed efficiency during two consecutive lactations of treatment.
Replacement of palm oil by thevetia oil in broiler chick diets
Authors: Atteh J. O. , Ibiyemi S. A. , Onadepo F. A. , Ugboma O. O.
Published: March 2009

The effects of replacing 0, 25, 50 or 100% of dietary palm oil (5%) with oil of Thevetia peruviana was investigated using broiler chicks 0–3 weeks old.

Increasing the content of thevetia oil in the diet reduced average daily feed intake and weight gain (P < 0·05) and decreased protein and fibre retention (P < 0·05) and fat retention (P < 0·01). However, there was no significant effect on feed: gain ratio or mortality rate. It is concluded that there is a need for further processing of thevetia oil before it can be used effectively as an ingredient in broiler feed.
A comparison of the responses of two cultivars of late-autumn-sown wheat to applied nitrogen
Authors: Webb J. , Sylvester-Bradley R.
Published: March 2009

At four pairs of sites in the UK, two cultivars of wheat, bred either for autumn (cv. Mercia) or for spring (cv. Tonic) sowing were sown in November 1988 and 1989 and their yield response to springapplied fertilizer N assessed over the range 0–320 kg/ha N. Grain samples were taken at harvest and analysed for those qualities regarded as indicators of suitability for milling. In five experiments, the grain yield of Mercia was up to 1 t/ha greater than that of Tonic, but overall there was no consistent difference between the two cultivars in the optimum economic yield (Yopt)or in the amount of fertilizer N needed to produce it (Nopt). Both cultivars produced c. 17·5 kg of grain per kg of fertilizer N applied up to Nopl. In the five experiments in which Tonic yielded less, it produced grain of greater N concentration than Mercia when given the same amount of fertilizer N. Differences in grain N concentration, while small (< 0·3%), were significant when analysed across sites. In six experiments both cultivars produced grain of 11 % protein at Nopt. There were no consistent or worthwhile increases in specific weight, Hagberg falling number (HFN) or response to the sodium dodecyl sulphate (SDS) sedimentation test of either cultivar from applying more fertilizer N than Nopl. The average specific weight of Mercia grain was 2·5 kg/hi greater than that of Tonic, while Tonic gave larger SDS values of c. 8. There was little difference in HFN. It was concluded that the yield requirement for fertilizer N was similar for these two cultivars of wheat when sown in late autumn, and there was no need to apply differential fertilizer N applications to the cultivars to produce grain of the quality needed for breadmaking. In four experiments the application of plant growth regulator (PGR) increased the yields of both cultivars by c. 0·5 t/ha.
Physical structure of white clover, rape, spurrey and perennial ryegrass in relation to rate of intake by sheep, chewing activity and particle breakdown
Authors: Mtengeti E. J. , Wilman D. , Moseley G.
Published: March 2009

Four plant species were compared in each of three harvest periods (in August/September) in 1991 and 1992 at Aberystwyth: white clover (Trifolium repens L.), rape (Brassica napus L.), spurrey (Spergula arvensis L.) and perennial ryegrass (Lolium perenne L.). Plant physical structure was considered in relation to rate of intake by sheep, chewing activity and the effectiveness of chewing in breaking the diet into particles.

White clover had a much lower proportion of cell wall than perennial ryegrass, but the rate of intake and the number of chews per min were similar for the two species. White clover petioles broke down into long, thin particles, similar in size and shape to those derived from perennial ryegrass leaf sheaths; many of the clover petioles were not split longitudinally by chewing, in contrast to the ryegrass sheaths. A white clover leaflet was typically broken into about 20 blocky particles, whereas a petiole of similar weight was broken into only about three particles. Veins were close together in ryegrass leaf sheaths and blades, particularly the latter; approximately one in seven strips of weaker tissue between veins was ruptured by chewing leaf sheaths and one in 16 in the case of leaf blades, in each case resulting in particles of c. 2 mm width. Rape had a low proportion of cell wall and a low proportion of vascular tissue in its leaf blades, petioles and stems. Rape leaf blades were eaten quickly, but the stems were eaten slowly. The length and width of particles derived from rape leaf blades were very similar to those of particles derived from white clover leaflets. Spurrey had a high proportion of cell wall and was low in in vitro digestibility, but the rates of intake and chewing were high and relatively few chews were required per g of dry matter ingested. The vascular bundles in the spurrey stems were only half the thickness of the bundles in white clover petioles; pieces of spurrey stem were typically broken at about two places along their length and were not split during eating.

The study illustrates the wide variation in plant anatomy among species which can be available to herbivores and some effects of the abundance, thickness and orientation of vascular bundles on rate of intake, chewing activity and the size and shape of particles produced by chewing.
Evaluation of the use of the purine derivative: creatinine ratio in spot urine and plasma samples as an index of microbial protein supply in ruminants: studies in sheep
Authors: Chen X. B. , Mejia A. T. , Kyle D. J. , Ørskov E. R.
Published: March 2009

In ruminants, the urinary excretion of purine derivatives (PD) reflects the absorption of microbial purines and can be used as an index of microbial protein supply. The objective of this study, carried out in Aberdeen, 1992, was to examine whether PD concentrations in spot urine or plasma samples vary diurnally during a given feeding regime and if they reflect differences in daily PD excretion induced by varying feed intake. Sixteen sheep were offered ad libitum one of four diets (fresh weight basis, the rest of each diet being minerals and vitamins): (1) 99·9% lucerne (pelleted); (2) 50% hay, 30% barley, 9% fishmeal and 10% molasses; (3) 72% straw, 7% molasses and 20% molassed sugarbeet pulp; and (4) 97% barley. Measurements were made for 1 week after a 2-week adaptation period. Urine was collected daily on days 1–4 and hourly on days 5–7. Hourly urine collection was achieved using a fraction collector. Plasma samples were collected hourly from 09·00 to 17·00 h on day 4. Feed intake varied considerably (347–1718 g DM/day) between diets and between animals. Daily excretion of PD (7·1–22·6 mmol/day) was linearly related to DM intake (r = 0·85, n = 16), and so was the microbial N supply (3·9–19·5 g N/day) estimated from daily PD excretion (r = 0·87). In hourly urine samples, the ratio of PD:creatinine concentrations showed no significant difference between sampling times, and was linearlycorrelated with the daily PD excretion (r = 0·92). Similarly, plasma PD concentration also showed little diurnal fluctuation. Glomerular filtration rate (GFR) increased with feed intake. Plasma PD was not well correlated with daily PD excretion in urine (r = 0·57). The tubular load of PD (plasma PD × GFR) was better correlated with the daily excretion (r = 0·80). It appears that when sheep are fed ad libitum, PD in spot urine may provide a practical indicator of microbial protein supply status.
Boron tolerance in wheat in relation to soil salinity
Authors: Manchanda H. R. , Sharma S. K.
Published: March 2009

A screenhouse study in Haryana in 1986/87 evaluated the effect of boron on the wheat cultivar WH147 grown in pots in a sandy soil at three salinities. Before sowing, 0–9 mg B/kg soil was added. Without added B the crop produced significantly more grain at electrical conductivity of the saturation extract (ECe) 6 dS/m than at other salinities, but at ECe 8 dS/m yields were similar to those in nonsaline (ECe 0·8) soil. Grain yield in nonsaline soil was not affected significantly even at the highest concentration of added B, even though at the boot stage the shoots had accumulated as much as 307 mg B/kg. At ECe 6 and 8 dS/m, grain yield was significantly less with 3 and 1 mg added B/kg, respectively, than without added B, even though the B concentration in the shoots was only 72 and 31 mg/kg, respectively. The results indicated that B tolerance decreased with increasing salinity of the soil, even though B absorption by plants was 24–62% less in saline than in nonsaline soil at similar B concentrations. As B and salinity often occur together, threshold values of B in soil and plants for optimum growth of wheat will differ with the ECe of the soil. The results suggested that Ca:B ratio in wheat straw is not a reliable indicator of B toxicity in the soil.
Growth of lambs offered fixed amounts of roughage and concentrate either simultaneously or sequentially
Authors: Wilkinson R. G. , Greenhalgh J. F. D.
Published: March 2009

Two experiments were carried out in Scotland 1984 to study the efficiency of energy utilization by Suffolk × Blackface lambs. In the first experiment, a digestibility trial, the lambs were fed three diets: roughage (R) consisting of chopped dried grass; concentrate (C) containing 700 g whole barley, 225 g ground barley and 75 g fishmeal/kg dry matter (DM); and a mixed diet (M) containing 500 g of roughage and 500 g of concentrate/kg DM. The DM and organic matter digestibility coefficients of diet M were lower than the ‘expected’ values calculated by summation of the separately determined digestibility coefficients of the component feeds. Similarly, the metabolizable energy (ME) value was 4·0% lower than expected.

In the second experiment, 40 lambs ofc. 20 kg live weight (LW) were offered 50 kg roughage DM (ME 9·74 MJ/kg DM) and 50 kg concentrate DM (ME 12·21 MJ/kg DM) either as a mixture (treatment M) or sequentially (treatment S). Lambs on treatment S took 33 days longer to consume their allocation of food than those on treatment M, but achieved a similar final empty body weight and empty body composition. This contrasts with results predicted by a feeding standards model for lambs of a similar LW offered diets of the same ME content. The longer feeding period, and hence greater overall maintenance requirement, of lambs on treatment S was partly offset by associated effects causing a reduction in the total ME available to lambs on treatment M, and partly to improved efficiency of energy utilization for gain and/or a lower daily maintenance requirement of lambs on treatment S. Allowing for associated effects and the adoption of a variable maintenance requirement in current feeding standards would result in a more accurate prediction of animal performance.
On the mathematical description of lactation curves
Authors: Rook A. J. , France J. , Dhanoa M. S.
Published: March 2009

The lactation curve may be represented mathematically by the general equationY= Aϕ1(t)ϕ2(t), whereAis a positive scalar, ϕ1,(t) is a positive monotonically increasing function with an asymptote at ϕ1= 1, and ϕ2is a monotonically decreasing function with an initial value of unity and an asymptote at ϕ2= 0. Functions considered as candidates for ϕ1were:(Mitscherlich),(Michaelis-Menten),(generalized saturation kinetic), 1/(1 +b0(logistic), b0exp(Gompertz) and [1+ tanh(b0+ b1t)]/2 (hyperbolic tangent). Candidates for ϕ2were e–ct(exponential) and 1/(1 +ct) (inverse straight line). The 12 models thus obtained andY= Atbe–ct(Wood's model) were fitted to whole-lactation data from 23 animals. Mitscherlich x exponential, Michaelis-Menten x exponential, logistic x exponential, logistic × inverse straight line and Wood's model all fitted well. For these models, expressions for time to peak, maximum yield, total yield over a finite lactation and relative decline at the midway point of the declining phase were obtained. The Mitscherlich x exponential model generally fitted better than Wood's model and, unlike Wood's model, gives simple algebraic formulae for all these summary statistics.
Wheat/chickpea intercropping under late-sown conditions
Authors: Ali M.
Published: March 2009

Field experiments to determine the optimum fertilizer treatment and ratio of wheat to chickpea in late-sown irrigated intercropped populations were done during the winter seasons of 1983–85 on sandy loam soils at the research station of the Directorate of Pulses Research, Kanpur, India. Of the three populations tested (2:2, 2:1 and 3:1 row ratios of wheat: chickpea), the 2:2 row ratio allowed more light interception and transmission to the lower canopy and gave significantly higher yield (4155 kg/ha wheat equivalent) and land equivalent ratio (LER) than the other treatments. Chickpea yields were reduced more than those of wheat under all intercropping systems and the reduction was largest at the 3:1 row ratio. Wheat (cv. Sonalika) was more productive than chickpea (cv. BG261). Application of the normally recommended rate of fertilizer to the wheat only was as effective as applying fertilizers, at the appropriate rates, to both the component crops; indicating that fertilizers applied only to wheat were adequate to meet the requirements of the associated chickpea also.