bluuebunny/crossref_metadata_2025 huggingface dataset:
Copper content of soil and herbage following pig slurry application to grassland
Authors: Parkinson R. J. , Yells Rosemary
Published: March 2009

Recent amendments to European Economic Community Feed Additives Directive 70/524 have lowered the maximum permitted copper content of pig rations because of concern about the environmental pollution risks that may be caused by land application of slurry containing high copper concentrations. The inclusion of copper compounds in pig feed improves growth rates and food conversion ratios, but 80–90% of dietary copper is excreted (Unwin, 1977), although the concentration in slurry varies widely according to diet and water intake. Repeated applications of pig slurry to grassland may result in copper-induced phytotoxicity and, more importantly, toxicity to grazing livestock, particularly sheep. However, the experimental evidence regarding the accumulation of copper in soil and herbage is inconclusive, and there is some difficulty in identifying ‘safe’ levels, as these vary according to soil type, herbage composition and herbage contamination (Batey, Berryman & Line, 1972; Bremner, 1981). Results are presented here on an experimental investigation into soil and herbage copper contents under three different slurry application rates at two permanent grass sites.
Stemflow in potato crops
Authors: Jefferies R. A. , MacKerron D. K. L.
Published: March 2009

Interception of rain by the plant canopy and stemflow resulting in non-uniform distribution of soil water beneath the canopy has long been recognized in forest trees (Eschner, 1967). Rutter (1975) stated that stemflow may vary from quite small quantities to as much as 20% of the net rainfall and Geiger (1965) had earlier quoted data both from Ovington (1954), who found stemflow to be 0·1–0·3% of rainfall in seven forest canopies, and from Eidmann (1959) showing that a fir and a beech canopy gave 0·7 and 16·6% respectively of the average rainfall as stemflow. However, there have been few studies of the distribution of rain beneath the canopies of agricultural crops despite the implications which non-uniform distribution might have for studies of crop water and nutrients.
Time of sowing and the development of winter wheat
Authors: Green C. F. , Paulson G. A. , Ivins J. D.
Published: March 2009

Research conducted on sowing dates has shown a trend towards increased yield as sowing is advanced for winter wheat (Darwinkel, Hay & Kuizenga, 1977; Walker, 1980) and winter barley (Selman, 1980; White, 1981). Green & Ivins (1985) have quantified the rate of yield decline for winter wheat as sowing is delayed after mid-September, giving a mean value of 0–35% per day. For a similar study on winter barley (Green, Furmston & Ivins, 1985) a yield decline of 0–43% per day delay in sowing was attributed to reductions in the number of ears per unit area as planting was delayed.
The genetic improvement of Syrian Awassi sheep with special reference to milk production
Authors: Hossamo H. E. , Owen J. B. , Farid M. F. A.
Published: March 2009

The improvement of milk production by the establishment of four specialized lines and subsequent within-line selection over a 7-year period under grazing conditions at Kraim station in mid-Syria is described. The specialized line showed a substantially higher total milk production amounting to a mean 25% superiority over the control line in 1979–81.

The heritability of total milk yield as estimated from paternal half sib analyses was 0·53 ± 0·169 for 2-year-old ewes and the genetic correlation of a single maximum daily yield record (+ 0·93) with total yield indicates the possibility of simplified selection procedures for this trait.

The effect of several other factors (for example, ewe age and season of lambing) on various aspects of lactation in Awassi ewes is reported.
Water stress and time of floral initiation in pearl millet
Authors: Mahalakshmi V. , Bidinger F. R.
Published: March 2009

The interaction of water stress and time from sowing to floral initiation was investigated in the field with pearl millet hybrid BJ 104. Extended daylength was used to delay panicle initiation (PI) and flowering (FL) of crops exposed to single periods of mid-season drought. Growth, yield and yield components were related to the number of days for PI and FL in both irrigated and water-stressed treatments. Delay in PI resulted in more leaves and tillers per plant, and greater leaf area, height and total dry matter. Grain yield, however, was not affected resulting in lower ‘harvest index’. There was, however, an increase in the grain yield of main shoots which was offset by a proportional decrease in the grain yield of tillers.

Water stress effects were dependent on the physiological stage of the crop at which stress occurred, as a result of the photoperiod treatments. Water stress prior to panicle initiation did not affect the grain yield of the main shoot but increased tiller grain yield, resulting in a higher total (crop) grain yield. Water stress during panicle development reduced the grain yield on the main shoot but this loss was compensated by the grain from the increased number of tiller panicles which reached flowering. Water stress during flowering and grain filling reduced grain yields of both main shoot and tillers, making this the most sensitive stage. Photoperiodic control of floral initiation can provide an escape mechanism to avoid the coincidence of mid-season water stress with sensitive periods of growth.
Comparative study of oestrous activity in Finn ewes and two Egyptian fat-tailed sheep under subtropical conditions
Authors: Aboul-Naga A. M. , Aboul-Ela M. B. , Hassan Ferial A.
Published: March 2009

Oestroua activity of three flocks of Ossimi (O) and Rahmani (R) subtropical fattailed and imported Finn (F) ewes was followed over a calendar year under the prevailing subtropical conditions in Egypt.

Rahmani had quite consistent oestrous activity throughout the year, with a slight drop in March and June, and may be regarded as a non-seasonal breed. Oestrous activity of the O ewes was lower than the R at different times of the year. They showed high individual variation. Most of the O ewes had an anoestroua period during July–September but had regular oestrous activity during their breeding season.

Overall number of oestruses per ewe per year was 15·9, 13·0 and 10·3 for R, O and F, respectively. Normal cycle length tended to be longer, though not significantly so, in both R and O subtropical breeds than the F (17·8 and 17·6v. 17·1 days). Heat duration was significantly longer in F (47·0 h) than in both local breeds (37·7 and 37·5 h for R and O, respectively).
Developmental characteristics of grass varieties in relation to their herbage production: 3. Tiller development in Dactylis glomerata and Loliutn perenne in relation to head emergence
Authors: Davies I.
Published: March 2009

Features of the gross morphology of primary growth of Dactylis glomerata and Lolium perenne, and associated changes in digestibility are described.

Species differences were noted with regard to the relationships between head emergence and the time when stem apices were raised to defoliation height, vegetative/ reproductive tiller ratios, and tiller size.

Also there were differences in the sequence of extension growth of leaf sheaths, internodes and inflorescence leading to emergence of the head. Associated changes in the vertical distribution of leaf blades were examined.

In perennial ryegrass extension growth of the inflorescence continued after emergence had begun, but not in cocksfoot. Weight increments in the inflorescence, from emergence onward, followed the same pattern in the two species, however.

Differences in the developmental patterns of the two grasses did not appear to influence their relative digestibility.

Upper internodes of reproductive tillers of S. 24 ryegrass declined rapidly in digestibility Species differences, and the pattern of changes in the digestibility of lower and upper parts of reproductive tillers are discussed in relation to mechanical aspects of sward development and micro-environmental effects.
The effect of calcium nutrition on the incidence of internal rust spot in the potato
Authors: Collier G. F. , Wurr D. C. E. , Huntington Valerie C.
Published: March 2009

Tubers produced by potato plants grown in vermiculite and supplied with either 0, 1 or 3 mM calcium chloride solution developed brown necrotic lesions of internal rust spot. Plants supplied with 9 and 27 mM calcium chloride solution did not show the symptoms and had a substantially greater concentration of calcium in the tuber dry matter. It is concluded that internal rust spot is a physiological disorder associated with a low concentration of calcium in the affected tubers.
Control of reproductive and pelt changes in ferrets: some experiments with animals kept entirely upon artificial light
Authors: Hammond J.
Published: March 2009

The effects, on induction and maintenance of oestrus and on pelt changes, were compared for various schedules of entirely artificial light of constant intensity.

A period of exposure to low environmental temperature was without effect on subsequent response to light treatment.

In one experiment, after periods on 6 hr. artificial light or on daylight, groups were put upon, daily, (i) 7 hr. light as 6 hr. + 5 hr. dark + 1 hr. light, (ii) the same total amount of light but divided as 6 hr. + 1 hr. separated by darkness increasing by 5 min. each day, and (iii) light increasing from 7 hr. by 5 min. daily. Groups (ii) and (iii) became oestrous together, later than group (i).

Subsequently all were placed on 7 hr. total light daily, applied in various ways. If given as a single continuous period daily, oestrus ended and moult into winter coat occurred. The latent period depended upon the treatment previously imposed. The duration of oestrus on treatment (i) was greater than normal.

In another experiment females were put on, daily, (iv) 24 hr. light, (v) 14 hr. light, and (vi) 4 hr. light as 2 hr. + 10 hr. dark + 2 hr. light. First response was seen on (vi), but on the average the quickest was on (v) and slowest on (iv). Thus darkness contributes to the induction of oestrus.

Possible interpretations are discussed.
The effects of dazomet and fertilizer nitrogen on field beans (Vicia faba L.)
Authors: McEwen J. , Salt G. A. , Hornby D.
Published: March 2009

The mean yield of field beans grown for three consecutive years on a site infested with migratory nematodes was 1540 kg grain/ha in untreated soil and 1870 kg/ha in soil treated with dazomet.

Fertilizer nitrogen in amounts up to 250 kg N/ha decreased yield to 990 kg in untreated soil but increased it to 2220 kg in soil treated with dazomet. Fertilizer nitrogen did not affect nematode numbers or root blackening but decreased nodulation and increased mycorrhizal infection by Endogone sp. in untreated soil. Dazomet greatly decreased migratory nematodes of the genera Tylenchorhynchus and Trichodorus and eliminated Pratylenchus. It had little effect on root blackening in the top 10 cm of soil but decreased it in the next 10 cm. Infection with Endogone was almost eliminated.
Intra-varietal variability and response to single plant selection inGossypium hirsutumL.: I. Phenotypic variability
Authors: Thomson N. J.
Published: March 2009

Populations of spaced plants of each of the four American upland cotton varieties Deltapine Smooth Leaf, Rex Smooth Leaf, Pope, and Rex and one African upland variety, Bar 7/8, were grown in the 1965–6 wet season at Kimberley Research Station, in the Ord River valley, Western Australia. The number of bolls, boll weight, lint percentage, seed cotton yield, lint yield, micronaire value, mature height, and morphological type were recorded for each plant.

For all varieties the range of each attribute was wide; for example, for a typicalvariety, boll weight ranged from 3·0 to 7·8 g, lint percentage from 30·5 to 43·5%, micronaire value from 3·3 to 5·9 units, and mature height from 78 to 195 cm.

The most variable varieties judged on coefficients of variation were those maintained at the station for the longest period without selection while the most recent accession was the least variable.

Frequency distributions for all attributes in each population departed significantly from normality: the majority showed both significant skewness and kurtosis. Positive skewness shown for the yield parameters seed-cotton yield, lint yield, boll number and boll weight in all varieties suggested there was scope for improvement by selection. Negative skewness for lint percentage was found in three varieties, suggesting previous intense selection for this trait. The coefficient of variation of lint percentage with one variety (Deltapine Smooth Leaf) was considerably less than that recorded 30 years earlier for its predecessor D x PL 11 A.

Covariance adjustments to seed cotton yield of individual plants, based on various hypotheses of the relationship between a plant's yield and that of its neighbours failed to give reductions of consequence in the variability of yield. It was concluded that inter-plant influences were far more complex than the models assumed.
The microbiology of four steamed soils
Authors: Oxley C. D. , Gray E. A.
Published: March 2009

Four soils, sterilized by steam at 100° C, with unsteamed controls for three soils, were examined at intervals up to 62 days to study the microbiology in relation to the abundance of ammonia, nitrites and nitrates of all the soils, the C/N ratios of two, and the pH and moisture content of three. After steaming, the soils were flooded with sterilized tap water equivalent in amount to 3 in. of rainfall at intervals varying with the particular soil. The soil of the first trial remained under water until very near the end of the experiment. In all the soils, the production of ammonia up to 14 days after steaming was associated with increased biological activity, generally a multiplication of bacteria associated with multiplication of Protozoa. The production of nitrites and nitrates was associated with a similar biological activity. Those bacteria that survived steaming had simple growth requirements as compared with those of the subsequent microflora. The Protozoa showed a series of ‘pulses’ of maximum and minimum abundance and there was also a succession of species in all the soils. A predilection of Protozoa for certain bacteria was shown by the association of certain species with particular groups of bacteria identified by Gram's staining. In two of the soils, there were ‘pulses’ of maximum and minimum abundance of diatoms, and in one soil diatoms possibly affected soil texture. The investigation showed that despite the contrasting characters of the soils, the major chemical changes were almost wholly attributable to biological activity, and that after steaming the same general reactions occurred in all. The investigation proved the importance of considering the microbiology of steamed soils as a problem in ecology.
The availability of calcium in three legumes of grassland
Authors: Armstrong R. H. , Thomas Brynmor
Published: March 2009

1. The availability of the calcium in three grassland species, all legumes, has been investigated, with the rat as experimental animal.

2. Two procedures involving determination of the calcium balance, (a) by analysis of feed, faeces and urine, and (b) by a slaughter technique, were used.

3. The foregoing methods gave results, for any one species, which were without significant difference. It is considered that the slaughter technique would be the less laborious when any large number of determinations has to be made.

4. The calcium in both lucerne and late-flowering red clover was available to a significantly greater degree than that in wild white clover. In all three species calcium availability was high.

5. The possible significance of the high faecal calcium found in rats receiving wild white clover has been discussed.

6. It was concluded that the extension of availability studies to a wider range of grassland species and of their ash-components would be desirable.
Physiology of seed yield in field beans (Vicia faba L.): II. Dry-matter production
Authors: Ishag Hassan M.
Published: March 2009

Dry weight per unit area was related to plant density differences and leaf area duration (LAD) up to pod-setting (late June). Total dry weight and seed dry weight at maturity were not related to total LAD or LAD after pod setting. Seed yield at a node was closely correlated with leaf area at the same node (r = 0·67 to 0·94).

Differences in net assimilation rate (NAR) between varieties were not significant. A substantial rise in NAR in July-early August was attributed to additional photosynthesis by pods.
The effect of body-weight loss on the composition of Brahman cross and Africander cross steers
Authors: Seebeck R. M.
Published: March 2009

Comparative slaughter was used to assess the effects of body-weight loss on Brahman cross (BX) and Africander cross (AX) steers of the F3 generation with respect to the empty body weight, the hot carcass weight and various offal components. Animals were slaughtered at design weights of 325, 341, 358, 374 and 390 kg, some while during positive body-weight growth (Group A) and others during weight loss from 390 kg at a rate of 0·5 kg per day (Group B).

AX animals had less empty body weight (B. B. W.) and dressed carcass weight (H. C. W.) at the same fasted body weight. Weight loss also reduced the amount of E. B. W. at the same fasted body weight but the effect on H. C. E. was not significant.

The breeds were very similar with respect to the various components of the offal, except that the AX had heavier heads. The weight loss treatment increased the proportion of the head, tail and feet, because these comparatively bony structures lost relatively little during the weight loss period. The heart was also relatively increased by the weight loss treatment. The liver, gall bladder, kidneys, total gut tissue, spleen and thymus were reduced relative to E. B. W. in Group B animals. The liver showed its most rapid weight loss in the early period of body-weight loss, being the only organ to show any variation in its rate of change during body-weight loss.

Body-weight loss caused changes in the distribution of the gut tissue, with a relative loss in the rumen-reticulum and a relative gain in the hind gut.
The effect of method and rate of application of common salt and muriate of potash on sugar beet
Authors: Holmes J. C. , Lang R. W. , Hunter E. A.
Published: March 2009

Twelve experiments in the East of Scotland tested a hypothesis that the smaller yield responses to salt in Scotland than in England shown by previous work was due to the adverse effects of soluble salt concentration brought about by ridging, and also to test a wider range of salt and potash than used previously. All combinations of three rates of salt (0, 315, 630 kg/ha) and three rates of muriate of potash (0, 315, 630 kg/ha) were applied in four ways: (1) ploughed down in winter, (2) on the furrow in February, (3) in the seed bed and (4) half as (1) and half as (3). Plant emergence was decreased by salt and potash in only three experiments and then only when the larger amounts of both fertilizers together, along with nitrogen and superphosphate, were applied in the seed bed prior to ridging. Both experiments were in a year when the weather was dry while the plants emerged. Yield of sugar was greatest with the February application on the furrow and smallest with the ploughing down method. At equal weights, salt and muriate of potash had similar effects on sugar yield. Equations derived from the response surface gave the most profitable dressing as 377 kg/ha of salt plus 127 kg/ha of K2O which gave a £4.90 greater margin per hectare over costs than the best potassium application without salt.
Response of dwarf wheat (Triticum aestivutm L.) to graded doses of P and K on soils of different available P status
Authors: Singh B. R. , Singh L. , Singh B. P.
Published: March 2009

Response of wheat to fertilizer-P on soils low and medium in available P increased with increasing doses up to 26 kg P/ha; responses were proportionately greater on medium-P soils. Application of 39 kg P/ha increased the response slightly on low-P but decreased it drastically on medium-P soils. The relatively small response on low-P soils may be due to fixation of fertilizer-P. The results indicate that the maximum response to fertilizer-P may be obtained only when P fixing capacity of the soil is satisfied so that sufficient P for the crop remains in the soil solution. The results of this investigation suggest that fertilizer should be applied on the basis of soil test data of individual fields instead of following regional recommendations.
Interpopulational and intervarietal F1 hybrids in Lolium perenne: performance in field sward conditions
Authors: Foster C. A.
Published: March 2009

Fifteen intervarietal F1hybrids and their parents were evaluated in two field sward trials, representing three levels of management intensity each maintained over a 2-year harvest period. The trials were sown in different years and at different sites. Several hybrids exhibited significant levels of heterosis for total annual dry-matter yield – up to 5–5 % mid-parent and up to 3–6 % higher-parent heterosis. Within individual trials mid-parent heterosis up to 8% was found, while at particular harvests over 25% heterosis was not uncommon. Comparisons made of performance in swards, simulated swards and spaced-plant conditions showed that genetic differences found maximum expression in non-competitive conditions. This was greatly reduced in simulated swards and further suppressed in sown swards in the field. Expression of heterosis was highly specific to the conditions in which it was tested, although the two hybrids most heterotic as spaced plants were also significantly heterotic in field swards.
Copper levels in diets for growing pigs
Authors: Braude R. , Ryder K.
Published: March 2009

Results of a co-ordinated trial carried out at twenty-one centres indicated that the performance of growing pigs (20–90 kg) can be improved by supplementation of their diet with copper sulphate.

Three levels of copper supplementation were tested, 150, 200 and 250 mg Cu/kg diet. Though significant improvements were recorded on all three levels, the best performance and the highest increase in profitability were obtained with 250 mg Cu/kg diet. With increasing dietary intake of copper, the copper content of the pigs' livers increased markedly.

The melting-point of subcutaneous fat was lower in carcasses of pigs that were given supplementary copper sulphate in their diet.
The expression of heterosis for yield in restored F1hybrid wheats and its interactions with seed rate and seed size
Authors: Sage G. C. M.
Published: March 2009

Seed of nine F1hybrid wheat genotypes was produced by wind pollination. In one trial, grown at two seed rates, the extent of heterosis for yield and two yield components was small and was not affected by seed rate. In an adjacent trial the extent of heterosis in three hybrids was found to be affected by seed size.
Fertility studies in relation to soil type
Authors: Calder F. W. , Macleod L. B.
Published: March 2009

Three soil types – Pugwash sandy clay loam, Woodburn gravelly loam and Kirkhill silt loam – were compared by response to fertility treatments over two cycles of a 4-year rotation of 1 -year oats (AvenasativaL.) and 3 years of a grass-legume mixture for hay production. A rotation was started each year on a new section of the experimental site during the first rotation so that all crops were being grown in any one year. Treatments were: N; 0, 56, 112 kg/ha for the first rotation, 0, 168 and 336 kg/ha for the second rotation; P2O5; 0, 84, 168 kg/ha, first rotation, 0, 252 and 504 kg/ha, second rotation; K2O; 0, 67, 134 kg/ha, first rotation, 0, 252 and 504 kg/ha, second rotation. Manure was applied at 0 and 22 t/ha. There was a significant difference in yield for the three soil types for first-, second- and third-year hay crops. Manure increased yield of all hay crops on all three soils, and oat yields on Woodburn and Kirkhill soils. There were varying responses to rates of application of individual nutrients on different soil types. Percentage of species in the hay stands varied between soil types and between years. The differences found between soil types support the basic reason for classifying and mapping soils.
Sources of variation in the fertility of a herd of zebu, British, and zebu × British cattle in Northern Australia
Authors: Seebeck R. M.
Published: March 2009

Results of matings made in the Belmont breeding programme from 1954 to 1968 have been analysed. The analysis has been made within three groups. (1) The foundation cows in the years 1954–9; (2) theF1generation which were mated within line in the years 1957–62; (3) theF2andF3generations which were mated within Africander cross (AX), Brahman cross (BX) and Shorthorn-Hereford (SH) lines in the years 1960–8. Fertility was based on the number of calves born, whether alive or dead, to the number of cows mated.

In the foundation cows, Hereford cows had a fertility 9% higher than the Shorthorns. The difference between the bull breeds was not significant although the mean for the Brahman bulls was 16% below the mean of the other three breeds. There was a large variation in the fertility of the Brahman bulls. The fertility of the Shorthorn cows was depressed (by 8%) in the lactating cows as compared with dry cows, while there was an opposite effect in the Herefords. These latter effects showed year to year variation.

In theF1generation the differences between the breeds were not significant although both the AX (76·4%) and the BX (81·2%) were more fertile than the SH (70·1%). Estimates of heterosis in theF1generation were 42% for the AX, 43% for the BX and 12% for the SH. Lactating cows were 7% more fertile than non-lactating cows. There were significant differences between the BX bulls used but not between bulls of the other two breeds. The effect of sires within breed on fertility of daughters was significant only within the SH, and the heritabilities of fortuity were estimated from the variance components for sires within breed to be 9%, 14% and 22% for AX, BX and SH respectively.

In theF2andF3data the breeds were significantly different in fertility with averages of 77%, 61% and 67% for AX, BX and SH respectively. Thus by comparison with the fertilities of theF1cows no loss of heterosis for fertility occurred in the AX, a very marked loss in the BX and only a slight loss in the SH. A significant interaction between age of cow and lactational status showed that in the mature cows, wet cows had a higher fertility than dry, while the converse applied in the 3-year-old cows. The interaction of lactational status with breed consisted of the wet zebu cross cattle having a relatively low fertility while the wet British cattle had a relatively high fertility. There were significant differences between bulls within each of the three breeds. The effect of sires was significant in the BX and SH. Heritabilities estimated from between sires within breeds variance components were – 12%, 22% and 25% for the AX, BX and SH respectively.
Sodium toxicity and cation imbalance in dry beans (Phaseolus vulgaris L.)
Authors: Ayoub Ali T. , Ishag H. M.
Published: March 2009

Leaf burn and gradual death were the characteristic symptoms of injury in P. vulgaris sown on a sodic soil. Plant growth, total leaf area per plant, number of stomata and epidermal cells per unit leaf area, and relative water content were drastically reduced in injured plants; these were associated with large sodium accumulation in the shoot resulting in cation imbalance.
Isozyme genetic similarity among rye (Secale cerealeL.) cultivars
Authors: Ramirez L. , Pisabarro G. , De La Vega M. Perez
Published: March 2009

The genetic structure of six rye (Secale cerealeL.) cultivars bred as forage cultivars was investigated by means of nine isozyme loci. The isozyme systemselectrophoretically studied were glutamic oxaloacetic transaminase; phosphoglucose mutase; phosphoglucose isomerase; acid phosphatase; malic dehydrogenase and 6-phosphogluconate dehydrogenase. Alleles present and their frequencies were very similar in all cultivars; thus genetic distances between cultivars ranged from 0·000 to 0·005. Likewise, a general excess of homozygotic plants compared with the expected number was observed in cultivars. The genetic structure of these populations is closely similar to other rye cultivars, bred for grain production, which were previously analysed.
The influence of seed type and plant density on variation in plant size of red beet (Beta vulgaris L.) crops
Authors: Benjamin L. R. , Bell N.
Published: March 2009

In each of three experiments, five seed lots, representing multigerm, monogerm, open pollinated and hybrid types, were grown at three plant densities and the time of seedling emergence, uniformity of within-row spacing, the weight of individual shoots and roots at four occasions were recorded.

Seedling emergence was more rapid in a May-sown experiment than in a March-sown experiment. The monogerm seed lot had a lower standard deviation of emergence time in the May-sown experiment and in all experiments had a more uniform within-row spacing than the other seed lots, but there was no consistent relationship between these two attributes and uniformity of root weight.

The mean weight of shoots and roots increased rapidly until 600 day °C above 6 had accumulated. The yield of shoots then remained constant at about 30 t/ha at 47 plants/ m2 and at about 40 t/ha at 188 plants/m2. The weight of roots increased throughout the experiments and yields of over 100 t/ha were achieved. The monogerm seed lot gave a ceiling shoot yield about 20% less than that of the other seed lots, whereas there were no large or consistent differences in root yield between the different seed lots. Shoot yield increased with plant density, especially at very early harvests, whereas root yield showed a variable response to density. At early harvests in all experiments, root yield increased with increasing density; at late harvests in one experiment, yield de-creased with density, but in another there was no marked response to density.

Coefficient of variation (c.v.) of root weight was only about 30% in young unthickened roots, but in older thickened roots was between 70 and 117% at 47 plants/m2, and in-creased to over 180% at 188 plants/m2. The c.v. of root weight of the monogerm seed lot was approximately 20% less than that of the other seed lots.

In a fourth experiment, plots were thinned to leave within each row either a uniform or a clumped distribution of seedlings of either uniform or variable size. Uniformity of spacing had no effect on variation in root weight 126 days after sowing, but selecting for seedlings of uniform size reduced the c.v. of root weight by approximately 20%.
Transferrin (β-globulin) type and milk and butterfat production in dairy cows
Authors: Ashton G. C. , Fallon G. R. , Sutherland D. N.
Published: March 2009

1. The transferrin types of 225 Jersey cows in thirteen herds, and 433 Australian Illawarra Shorthorn cows in twenty-four herds in Queensland were determined. The effect of transferrin type on lactation length, milk yield, butterfat yield and butterfat percentage was assessed by a leastsquares multiple linear regression analysis.

2. The results for the two breeds did not differ significantly. Combining the data from both breeds, it was found that on average D/D cows had lactations 13·9 days longer than A/A cows (P < 0·01), and yielded 449·7 lb. more mills (P < 0·01). The results for A/D cows were intermediate.
Studies in the muscles of meat animals. IV. Comparative composition of muscles from ‘doppelender’ and normal sibling heifers
Authors: Lawrie R. A. , Pomeroy R. W. , Williams D. R.
Published: March 2009

1. Fourteen muscles from a normal 46-week-old Friesian heifer and from its 40-week-old half-sister, which showed the pronounced muscle hypertrophy of ‘doppelender’ cattle, were analysed for moisture, hydroxyproline, sodium, potassium, total nitrogen, and intramuscular fat: the iodine number of the latter was determined. In four of the muscles sarcoplasmic, myofibrillar and stroma nitrogens were also estimated.

2. Hypertrophy was associated with a mean increase in the percentage of total nitrogen, with markedly lower percentages of hydroxyproline and of intramuscular fat, and with a decreased K/Na ratio.
A semi-micro dry-block and automated analyser technique suitable for determining protein nitrogen in plant material
Authors: Starr Carol , Smith D. B.
Published: March 2009

A dry-block digestion system suitable for the estimation of total protein nitrogen in plant material has been evaluated. The method was found to be as accurate as Kjeldahl flask digestion, required much less fume cupboard space and enabled samples to be dealt with in large batches through weighing, digestion and analysis. The batch size can be designed to be compatible with the autoanalyser capacity. These advantages result in more rapid analysis with less chance of errors and accidents. A 45 min digestion period was found suitable for several crop species of widely different protein content, only field bean seeds required longer digestion time. Using the technique described samples are digested at a relatively low temperature (330 °C) for a short time and digests do not solidify on cooling. The autoanalyser method for determining ammonia concentrations in barley and malt digests (Micheson & Stowell, 1970) has been slightly modified for use with the plant materials studied. The dry-block and autoanalyser system is rapid, precise and compact, requires small amounts of tissue and is suited to the routine analysis of breeding material.
The influence of formic acid and formaldehyde additives and type of harvesting machine on the utilization of nitrogen in lucerne silages: 2. Changes in amino-acid composition during ensiling and their influence on nutritive value
Authors: Barry T. N. , Mundell D. N. , Wilkins R. J. , Beever D. E.
Published: March 2009

Lucerne was made into ten silages using either a flail or a precision-chop harvester with application of formaldehyde or a range of rates of formic acid during harvesting. Amino-acid analyses were done on the silages and on samples taken from the herbage at ensiling.

In excess of 70% of aspartic acid, serine, glutamic acid, tyrosine, threonine, lysine, histidine and arginine were destroyed in untreated silages when a flail harvester was used and in excess of 50% when a precision-chop harvester was used. Glycine, leucine, iso-leucine, valine and methionine showed little change, with net losses or increases of up to 10%, whilst proline, cystine + cysteine and phenylalanine were intermediate between these two categories. Net synthesis of alanine and α and γ amino-butyric acids occurred in the untreated silages. Increasing rates of formic acid addition, and the use of the precision-chop harvester, reduced the loss of the amino acids which were extensively degraded in the untreated silages and minimized the increases in alanine and α and γ amino-butyric acids. Formaldehyde treatment also reduced amino-acid degradation, apart from apparently high losses of lysine, histidine and tyrosine. It was concluded, however, that these losses arose through problems of estimation in formaldehyde-treated silages following HCl hydrolysis.

It is suggested that the most probable precursors for alanine and α and γ aminobutyric acids were respectively aspartic acid, threonine and glutamic acid. Voluntary intake and the utilization of silage nitrogen by young sheep were related to the net changes in amino acids involved in decarboxylation reactions, the best measures of this being the interconversions involving the formation of alanine and α and γ aminobutyric acids. Deamination reactions appeared to be of much less importance in limiting silage nutritive value than those involving decarboxylation.
An evaluation of pasture quality with young grazing sheep. I. Live-weight growth and clean wool production
Authors: Gallagher J. R. , Watkin B. R. , Grimes R. C.
Published: March 2009

1. In a grazing trial with sheep, cocksfoot, ryegrass and tall fescue were grown with and without white clover, under ‘short’ and ‘long’ management systems, and also white clover.

2. Live weights were recorded every 2-3 weeks, and wool production was estimated by clipping midside patches every month.

3. Sheep on grass plus clover plots were significantly superior to sheep on grass plots in terms of live-weight gain, final live weight and clean-wool production.

4. Sheep on ‘long’ pastures were significantly heavier than sheep on ‘short’ pastures for a month in the early part of the trial. Thereafter, differences in live weight were not significant.
Animal production studies in Jamaica. II. The development and evaluation of a field programme of calf weighing
Authors: Creek M. J.
Published: March 2009

1. The age of 210 days was selected for calf weight standardization. In general this is a preweaning weight under prevailing Jamaican conditions, and it represents a compromise between a very early age (90–120 days) which would reflect closely the milking ability of the dam, and the actual weaning age (approximately 260 days) when the grazing management of the herd would constitute a major unpredictable variable.

2. Either one or two weighings taken between the fourth and the ninth months of life was used to standardize calf weights to 210 days of age. In either instance for groups of calves, a mean estimate was derived which was very close to the actual mean 210-day weight, and which was suitable for data relating to groups of animals.
Animal production studies in Jamaica. III. The effect of dam age upon the 210-day weights of calves, and the response of male and female calves to different environments
Authors: Creek M. J. , Nestel B. L.
Published: March 2009

1. The data used in this study were the estimated 210-day weights of 2351 calves born on eight farms in the years 1958–61. In each year data were only used from herds which recorded at least five calves of each sex in that year. One hundred such herd years were included in the study.

2. The mean 210-day difference in weight between male and female calves was 27 lb. 1202 male calves had a mean weight of 380 lb. and 1149 female calves had a mean weight of 353 lb.

3. The response of calf weight to age of dam was different in the two sexes. The weight of the female calf was found to increase with dam age in a linear fashion, whereas the response of male calves was best described by a quadratic relationship with the maximum response at a dam age of 8 years.
Some liver enzyme levels in the late pregnant and early parturient ewe and the effect of dietary restriction in late pregnancy
Authors: Patterson D. S. P.
Published: March 2009

1. The effect of undernutrition on the levels of five enzyme activities has been observed in liver biopsy specimens taken from Suffolk-cross ewes in late pregnancy.

2. There was no significant effect on the levels of three important NADPH2-generating enzymes (i.e. glucose-6-phosphate, 6-phosphogluconate and tsocitrate dehydrogenases) when comparisons were made between groups of animals at the same stage of pregnancy. However, the proportion of very low 6-phosphogluconate dehydrogenase levels assayed in livers of the undernourished ewes was significantly increased as parturition approached.
Studies on forage cell walls: 2. Conditions for alkali treatment of rice straw and rice hulls
Authors: McManus W. R. , Choung C. C.
Published: March 2009

A number of studies on sodium hydroxide treatment of rice hulls and straw are reported. Alkali levels ranged from 0 to 100 g NaOH/100 g for hulls and from 0 to 50 g NaOH/100 g for straw.

Effects of prior grinding, prior irradiation with gamma rays (0–50 Mrads), alkali reaction time (0–24 h), neutralization of excess residual alkali with acids, and rinsing effects were studied in terms of increased salt (ash) content, test material solubility in water and in vitro and in vivo (terylene bag) fermentation.

Moderate increases in solubility and digestibility of straw followed irradiation but not for hulls. Major increases were found for irradiated straw further treated with alkali but hulls were little affected by 5 g NaOH/100 g D.M. except at the 50 Mrad level. Nutrient fortification of inocula media did not help dissimilation. Grinding had little effect on degradation of alkali-treated hulls. Straw responses were greater than for hulls.

Alkali treatment removed encrusting silica and lignin from rice hulls and increased in vitro and in vivo digestibility. Above levels of 12·5 g NaOH/100 g dry matter in vitro digestibility was depressed unless residual alkali was neutralized. Alkali-treated hulls were reduced in silica content better by rinsing or by no neutralization and no rinsing: neutralization or neutralization followed by rinsing were less effective. Lignin was best removed by alkali or alkali and acid without rinsing. Alkali reaction time on hulls was not critical, but alkali concentration was.

Animal trials indicated useful intake and digestive responses to alkali-treated rice hulls. Raw rice hulls were rejected by sheep.

When fed in a mixed diet with lucerne chaff (40% whole rice hull, 60% lucerne chaff) daily voluntary intake of rice hull dry matter was 345 g (nil NaOH); 361 g (10 g NaOH/ 100 g rice hull); 193 g (20 g NaOH/100 g rice hull) with apparent dry-matter digestibility values for the hulls of 20%, 41% and 51% respectively.
Large-scale isolation of fraction 1 leaf protein (18S) from lucerne (Medicago sativaL)
Authors: Jones W. T. , Mangan J. L.
Published: March 2009

Fraction 1 protein (18S) can be isolated in large quantities (order 100 g) in a soluble state by heating lucerne juice, adjusted to pH 6·7 to 6·9, from a Pirie extractor to 63 °C for 10 min. Low speed oentrifugation (2500g) removed coagulated chloroplast fragments and most of the heat-denatured Fraction 2 proteins. Fraction 1 (18S) protein (> 95% pure) was purified from low molecular weight materials (sugars, phenolics etc.) by ammonium sulphate fractionation and gel filtration on Sephadex G-75 gels.
The phosphorus requirement of pregnant sheep
Authors: Sykes A. R. , Dingwall R. A.
Published: March 2009

Thirty-eight mature Scottish Blackface sheep were mated at pasture and 32 brought indoors when 3–4 weeks pregnant. Eight were killed at this stage as controls (CI). The remaining 24 were offered a basal hay ration (200 g/head/day) supplemented with a semi-purified diet containing 84 g crude protein/kg and either 1·5 (P1), 2·8 (P2) or 9·3 (P3) g P/kg dry matter. The rate of feeding of the supplement allowed a mean daily P intake (g/day) in groups P1, P2 and P3 of 1·1, 1·6 and 4·7 and 1·6, 2·5 and 7·9 during weeks 4–15 and 16–21 of pregnancy, respectively. Six well-nourished sheep, fed conventionally, provided control ewes and lambs.

Balance trials were conducted on four sheep from each of groups P1 P2 and P3 during weeks 9–10, 14–15 and 19–20 of pregnancy. All sheep were slaughtered at parturition and selected bones of ewes and lambs removed for histological and chemical examinations. Whole body fat, nitrogen, Ca and P contents of the ewes and mineral content of the lambs were determined.

The faecal P excretion of the P1 sheep ranged from 10·8 to 19·1 mg/kg body weight/ day; urinary P excretion ranged from 0·7 to 2·9 mg/kg body weight/day in early and mid-pregnancy and from 1·0 to 8·1 mg/kg body weight/day in late pregnancy. It is suggested that on this evidence the minimum net faecal and urinary endogenous P loss can be no greater than about 13·5 mg/kg body weight/day. Carcass analysis and bone histology and chemical composition confirmed that the P requirement of pregnant ewes is much smaller than has been generally assumed.

It is suggested that for a 50-kg ewe carrying twins the P requirement increases from an average of 1·1 g/day during the first to about 2·5 g/day during the last month of pregnancy.
Thin sows: 1. Observations on the fecundity of sows when underfed for several parities
Authors: DeB. Hovell F. D. , MacPherson R. M.
Published: March 2009

Six pairs of gilts were taken at first mating. One of each pair was given about half the A.R.C. recommended amounts of protein and energy during pregnancy and lactation until she became anoestrus (thin group). The other gilt of each pair was given the same amount of protein, but double the amount of energy (standard group).

All the thin sows lost condition and became infertile. Their appearance conformed to that of sows with the ‘thin sow syndrome’. This took up to three reproductive cycles. There was no clear effect on the number of piglets born, but the litters of the thin sows contained an increasing proportion of small piglets. One of the thin sows died in her second pregnancy. The standard sows performed well producing an average of 10·3 piglets weighing 1·4 kg over three parities.

There were no differences between the two groups in their digestive efficiency. The thin sows retained less nitrogen in the later stages (days 80–100) of their first pregnancy than did the standard sows.

There were no differences between the groups in milk production during the first lactation when litters were standardized at eight piglets. There was some evidence that in the second lactation the thin sows secreted less fat and lactose.

The five remaining thin sows were repleted at the end of the experiment when their average weight was 96 kg. They were mated as quickly, produced litters which were as large, and piglets which were as heavy as those produced by the standard sows whose mating weight was 182 kg.
Dried poultry manure as a source of phosphorus for sheep
Authors: Field A. C. , Munro C. S. , Suttle N. F.
Published: March 2009

Feeding and balance trials with32P were carried out to measure the true absorption of P in battery and broiler waste and to assess the risk of urolithiasis in sheep.

Groups of six, 8-week-old Scottish Blackface lambs were given one of eight experimental diets containing barley and either 15, 30, 45 or 60% of dried broiler or battery waste. After about 12 weeks on the diet, balance trials with32P were conducted on a sample of the female lambs from each dietary group. The phosphorus intakes ranged from 4·6 to 15·9g/day.

Poultry waste was a good source of P. The proportion of dietary P absorbed by the lambs (A) ranged from 0·49 to 0·90 and was inversely related to the dietary intake of P (I). The relationship was A = 0·893 – 0·0219I. All lambs were in positive P balance (0·24–2·81 g/day), but only the bones from the lambs consuming the diets containing 45 and 60% broiler waste were not osteoporotic.

All lambs absorbed more P than they retained and the partition of the excess between urine and faeces were very variable.

No clinical cases of urolithiasis were seen, but uroliths were found at post-mortem. The incidence was highest in lambs consuming broiler waste and in lambs consuming the diets containing 15% poultry waste.
Comparison of direct drilling, reduced cultivation and ploughing on the growth of cereals
Authors: Ellis F. B. , Elliott J. G. , Barnes B. T. , Howse K. R.
Published: March 2009

This paper gives measurements of soil physical conditions and root growth made in the experiment described in the previous paper. The effect of methods of tillage on soil properties (strength, bulk density, nutrient distribution and fauna) and the effects on root development and the absorption of nutrients from different depths in the soil were investigated. The procedures used for these measurements are described.

Greater soil compaction occurred in all years after direct drilling. The growth of seminal roots of young plants was reduced by direct drilling in each year but only in the first year were there significant differences in root development between treatments at later stages of growth. Similarly, in each year early shoot growth was reduced by direct drilling but, with the exception of the first year, the plants were subsequently able to compensate adequately. Direct drilling resulted in more earthworms being present in the soil, and caused the surface soil to be more friable and contain a higher concentration of available phosphorus and potassium.