bluuebunny/crossref_metadata_2025 huggingface dataset:
Shorn and unshorn Awassi sheep I. Body temperature
Authors: Eyal E.
Published: March 2009

1. The rectal temperatures of shorn and unshorn Awassi sheep were measured at various hours of the day and during various seasons of the year in two different locations in Israel.

2. An increase in body temperature accompanied an increase in environmental temperature. A steeper temperature increase was noted in shorn sheep kept in the shade. When ambient temperatures were below 30° C. the body temperature of shorn sheep was lower than that of the unshorn sheep by an average of 0·16° C.

3. When ambient temperatures were above 30° C. the body temperature of shorn sheep was equal to or higher than that of unshorn ones.

4. Upon exposure to direct sunlight, the body temperature of shorn sheep exceeded that of unshorn animals. However, when the animals were transferred to the shade, or after sunset, the shorn sheep cooled at a faster rate. Their body temperature fell below that of the unshorn sheep during the cool hours of the day.

5. Wind velocity, both in the shade and in the sun, had a greater effect on shorn than on unshorn sheep.

6. A rise in the relative humidity of ambient temperatures above 25° C. caused body temperature to rise, particularly in unshorn animals. The body temperature of shorn sheep exceeded that of unshorn ones when the animals were maintained in a hot and dry environment.

7. While the body of the shorn sheep was entirely affected by the macroclimate, the unshorn sheep were greatly influenced by the microclimate existing in the fleece. Fleece temperatures always lagged behind and were rarely equal to environmental temperatures. Since it was postulated that heat tolerance of certain animals was related to their ability to exploit cool hours of the day, it is suggested that in certain ‘tolerance tests’ records should be taken not only during exposure to heat but also during cool hours of the day.
Upgrading the indigenous poultry of Uganda I. The growth rates and feed conversion from hatching to maturity of indigenous poultry crossed with four imported breeds
Authors: Trail J. C. M.
Published: March 2009

1200 chicks comprising 300 each of Light Sussex × indigenous, Rhode Island Red × indigenous, White Leghorn × indigenous and Black Australorp × indigenous cross-breeds were reared from day old to 24 weeks under good conditions of feeding and management and growth rates, food consumption and feed conversion measured weekly to assess any improvements brought about by cross-breeding the indigenous poultry of Uganda and compare the value of the four imported breeds for this purpose.

Growth rates of the indigenous birds were greatly improved by crossing with Light Sussex, Rhode Island Red and Black Australorp cockerels, the Light Sussex cross giving the best results, but the White Leghorn cross not greatly improving the growth rates of the indigenous birds.

Crossing with Light Sussex and Rhode Island Red cockerels gave birds with greatly improved feed conversion figures over the indigenous poultry, with the Light Sussex cross again being superior, and nearly as good as the imported breeds. Crossing with Black Australorp and White Leghorn cockerels did not produce birds with improved feed conversion rates over the indigenous poultry.
Upgrading the indigenous poultry of Uganda III. Shell and egg interior quality
Authors: Trail J. C. M.
Published: March 2009

Albumen quality, shell thickness and incidence of blood and meat spots in eggs from the progeny of indigenous poultry of Uganda crossed with four imported breeds were compared with results from the pure imported Rhode Island Red breed and discussed relative to figures previously obtained from indigenous poultry. The measurements were taken for a 5-day period during the 12th month of age of the birds when maintained under a high environmental temperature in Uganda.

The albumen quality of all four cross-breeds, as measured by Haugh units, was significantly higher than that of the Rhode Island Red breed.

All four cross-breeds produced eggs with shells significantly thicker than the Rhode Island Red, only slightly below the generally accepted figure of 0·013 in.

The incidence of both blood and meat spots was lower in all four cross-breeds than in the Rhode Island Red, in the case of blood spots significantly lower in one cross-breed and in the case of meat spots significantly lower in three cross-breeds.
Soil changes in ley-arable experiments
Authors: Low A. J. , Piper F. J. , Roberts P.
Published: March 2009

The effects of four five-course and six four-course rotations on some physical and chemical properties of a sandy loam overlying London Clay are reported.

Periods under ley increased the water stability of the air-dry soil aggregates, the resistance of moist soil aggregates to simulated raindrops, the rate of drainage under 60 cm. of water tension as measured in the laboratory, decreased the draw-bar pull during ploughing and the force required to crush air-dry aggregates. These effects increased with the number of years under grass.

After 2 years of arable cultivation the effect of a 3-year ley on water-stable aggregation was still apparent whereas the effect of a 2-year ley had largely disappeared, and those of a 1-year ley had completely disappeared.

A 2-year ley in a five-course ley-arable rotation was sufficient to maintain the total soil nitrogen at about 0·16%. With one year of ley in a four-course rotation a slow decline in nitrogen was found when the initial level was about 0·21%.

The rate of CO2 formation in soils of the arable break was proportional to the number of years they had been under ley; the longer the period the greater the volume of CO2 produced.

Evidence is presented that fertilizer nitrogen is used most efficiently by cereals growing in soil in good physical condition. This is usually best following a period under grass.
Effects of potassium fertilizers, age of ewe, and small magnesium supplementation on blood magnesium and calcium levels of lactating ewes
Authors: Hemingway R. G. , Ritchie N. S. , Rutherford A. R. , Jolly G. M.
Published: March 2009

1. An experiment is described which investigated the effects of potassium fertilizer, age of ewe, and a small magnesium supplement, on the plasma magnesium and calcium levels of ewes shortly after lambing.

2. Three potassium treatments (0, 1, and 2 cwt. muriate of potash/acre) were used, each being replicated six times, which gave a total of eighteen plots. Each plot was grazed by two old and two young ewes. One ewe of each age in every plot was given supplementary magnesium in the form of two magnesium heavy pellets, which released a total of 150 mg. Mg/day.

3. 22% of the ewes had plasma magnesium values below 1·0 mg. Mg/100 ml. on at least one sampling occasion during the experimental period. There was only one clinical case of tetany.

4. Neither potassium fertilizer use, nor magnesium supplementation influenced plasma magnesium and calcium levels of the ewes. Old ewes had greater temporary falls in plasma magnesium values and had consistently lower plasma calcium values.

5. Attention is drawn to the large individual variation between animals and the consequent need for providing adequate statistical analysis of experiments of this type.
Results of an experiment at Rothamsted testing farmyard manure and N, P and K fertilizers on five arable crops II. Nutrients removed by crops
Authors: Williams R. J. B. , Cooke G. W. , Widdowson F. V.
Published: March 2009

1. The amounts of N, P and K recovered by five arable crops and by permanent grass from soil alone, and from fertilizer and farmyard manure (FYM) dressings were measured. All the crops responded well to P and K fertilizers and all except clover responded to N. Uptakes from soil alone are therefore the maximum amounts of each nutrient that each crop could remove when supplied with other fertilizer nutrients (the exchangeable Ca and Mg in the soil were adequate).

2. Permanent grass (free from legumes) obtained about 114 lb. N/acre each year from soil and other natural sources; winter wheat obtained 1001b. N, kale and potatoes about 80 lb. N and spring barley only 57 lb. A 1 year ley of clover and grass fixed at least 1 cwt. N/aere/year. Permanent grass removed most P from soil (17 lb./acre a year), potatoes removed least (6 lb. of P) and other crops intermediate amounts. Most K was taken from soil by kale (70 lb. K/acre/year) and least (20 lb.) by potatoes. Annual variations in the amounts of nutrients recovered from soil by any one crop were much greater with K than with N or P.

3. Most fertilizer N was recovered by kale and least by potatoes; with these crops two-thirds and one-third respectively of the light dressing was recovered, percentage recovery from the higher rate of N tested was less. Kale and the 1 year ley recovered nearly one-quarter of the P applied, permanent grass recovered little more than one-tenth. Clover-grass ley recovered most fertilizer K, apparently taking up four-fifths of that applied. Potatoes, kale and permanent grass all recovered more than half of the fertilizer K given, cereals were least efficient although both responded well to K dressings.

4. Farmyard manure supplied large amounts of nutrients to all crops. Similar amounts of N, P and K appeared to be recovered from FYM whether or not NPK fertilizer was also used. A rough estimate was that crops like kale, potatoes and permanent grass, which received FYM each year, recovered about 30 lb. of N, 4 lb. of P and 75 lb. of K from a 10 tons/acre dressing.
The herbage intake of cattle grazing lucerne and cocksfoot pastures
Authors: Alder F. E. , Minson D. J.
Published: March 2009

1. From 1955 to 1957 a cattle grazing experiment was carried out on lucerne and cocksfoot pastures. Hereford-cross steers were used. Results obtained on the assessment of herbage intake either by the use of chromic oxide and faecal index methods or by herbage sampling are presented here.

2. Except in 1955, when techniques were being developed, the digestibility of the herbage on offer to the bullocks was estimated by cold storing herbage, cut with an Allen Autoscythe and later feeding it to sheep in indoor digestion trials. The in vitro digestibility of herbage samples cut in 1955 and 1956 was also determined.

3. In 1956 the mean intake of organic matter (lb.) per 100 lb. live weight by faecal methods was 2·38, 2·07, 2·20 and 2·29 on pastures of lucerne, cocksfoot, lucerne/cocksfoot (broadcast) and lucerne/cocksfoot (alternate 1 ft. drills), respectively, and 1·99, 1·76, 2·02 and 1·97, respectively, in 1957.

4. In 1956 the mean intake of organic matter (lb.) per 100 lb. live weight by herbage sampling methods was 2·14, 1·70, 2·11 and 1·99 on the same pastures of lucerne, cocksfoot, lucerne/cocksfoot (broadcast) and lucerne/cocksfoot (drills), respectively, and 2·49, 1·32, 2·35 and 2·03, respectively, in 1957. The modified Tarpen trimmer, cutting to within 1 in. of the ground was used for sampling in 1956 and the Allen Autoscythe cutting to within 2 or 3 in. of ground level in 1957.

5. Detailed botanical separation of herbage samples showed that the bullocks were selecting the more digestible parts of the plants; the top 4 in. of lucerne and the ends of leaves and stems of cocksfoot. This and other factors which could affect the estimates of digestibility of herbage eaten by the cattle are discussed together with possible sources of error in the herbage sampling methods.
A comparison of feeding growing pigs once or twice daily
Authors: Braude R. , Townsend M. Jill , Harrington G. , Rowell J. G.
Published: March 2009

1. A co-ordinated trial has been carried out at 17 centres to compare the effects on performance and carcass quality of feeding growing pigs once or twice daily.

2. No significant differences were found between growth rate, efficiency of food conversion or length of pigs on the two treatments.

3. Killing out percentage was on average 0·92% worse for the pigs fed once daily, a significant effect, probably because the pigs on the two treatments received different amounts of food at the last feed before slaughter.
Residual value of superphosphate and rock phosphate on an acid soil I. Yields and phosphorus uptakes in the field
Authors: Mattingly G. E. G. , Widdowson F. V.
Published: March 2009

1. A field experiment on an acid soil long in arable cropping at Rothamsted measured residual effects of superphosphate, applied at several rates, and Gafsa rock phosphate applied at a single rate. Residues were valued after 1 year with barley, and after 2 years with rye-grass. In each year, the value of the residues was related to yields from fresh superphosphate dressings taken as standards. ‘Percentage fresh superphosphate equivalents’ of the residues were determined using yields and P uptakes of both crops. An isotope dilution method with 32P was also used with barley. The experiment was continued for 2 further years without applying phosphate fertilizers, to measure yields and P uptakes from the residues and yields and P uptakes from rock phosphate relative to superphosphate.

2. ‘Percentage fresh superphosphate equivalents’ of residues of superphosphate for barley varied with the growth of the crop and with the method used to calculate them. They were 21–24%6 weeks after sowing, measured from yield, P uptake or isotope dilution. At harvest, they were 26% from yield, 43% from P uptake and 49% by isotope dilution. ‘Percentage fresh superphosphate equivalents’ 6 weeks after sowing increased with the rate of superphosphate but at harvest were independent of rate. ‘Percentage superphosphate equivalents’ of Gafsa rock phosphate were much smaller; they increased from 2–3% 6 weeks after sowing to 7–12% at harvest.

3. With rye-grass ‘percentage fresh superphosphate equivalents’ of residues of superphosphate applied either 1 or 2 years previously also varied with growth. All methods of valuation showed that residues were about twice as effective after 1 year as after 2 years in the soil. ‘Percentage fresh superphosphate equivalents’ derived from P uptake remained constant during growth and were 37–38% for superphosphate applied 1 year before and 18–20% for superphosphate applied 2 years before. Values derived from rye-grass yields decreased during growth from 76 to 45% (1-year residues) and from 38 to 21% (2-year residues).

4. After cropping with barley for 2 more years, there was little difference between yields or P uptakes from equal amounts of superphosphate whether applied 3 or 4 years previously. Residues from rock phosphate were almost equivalent to those from superphosphate after 3–4 years.

5. Apparent recoveries of superphosphate, as percentages of the amount applied, decreased with rate. The apparent recovery of P by crops in 5 years was about 21% from superphosphate and about 10% from rock phosphate when both were applied at 3·0 owt. P2O5 per acre.
The effects of single compared with split applications of fertilizer nitrogen on the yield and seasonal production of a pure grass sward
Authors: Castle M. E. , Reid D.
Published: March 2009

In a 2-year experiment conducted on a pure S. 24 perennial ryegrass sward, fertilizer nitrogen in the form of ‘Nitram’ (34·5%) N was applied at rates of 100, 200 and 300 lb/ acre either as single dressings in the spring or as two, three, four or five split dressings at successively later dates in the growing season. Total yields of herbage dry matter and of crude protein, and their distribution over the season, were determined by cutting the herbage five times at intervals of approximately 5 weeks. Yields of herbage dry matter were increased by increasing the nitrogen application rate and by splitting the total amount of fertilizer nitrogen into either three or four equal dressings. The mean crudeprotein content of the herbage dry matter was increased by increasing the nitrogen application rate, but it was reduced by splitting the total amount of fertilizer into several dressings. The nitrate content of the herbage was higher after a single heavy dressing of fertilizer nitrogen than after several split dressings. It is concluded that the optimum application programme for a total rate of 100 lb nitrogen/acre was three split dressings each of 33J lb/acre, and for the 200 and 300 lb nitrogen/acre rate, four split dressings of 50 and 75 lb/acre respectively.
The growth of vining peas: I. The effect of time of sowing
Authors: Milbourn G. M. , Hardwick R. C.
Published: March 2009

Yield and growth analysis have been applied to the results of an experiment comparing early and late sown peas. Yield analysis showed that in this experiment late sown peas had:

(i) fewer podding nodes per main stem,

(ii) fewer pods per podding node, and

(iii) a slower rate of increase in pod weight.

The physiological origins of these differences are discussed.

The first component is determined by the stage at which node production is terminated by the death of the apical bud.

The second is determined by morphogenetic factors at the apical meristem early in in the life of the plant, when (in the variety DSP) either a single or a double flowered raceme is initiated, and also during the harvesting period when some pods are lost from the lower-most flowering nodes.

The differences in the third component, the rate of increase in pod weight, could not be explained by conventional growth analysis. Pod growth rate was not a simple function of leaf area index.

It is suggested that the relationship between leaf area and pod growth rate is complicated by the existence of other sources of materials for pod growth such as stored products in the roots and stems, and photosynthesis by the fruit itself.
Comparative studies of perennial ryegrass and cocksfoot as food for the calf
Authors: Alder F. E. , Cooper E. M.
Published: March 2009

1. Perennial ryegrass (S. 23 and S. 24 sown together) and cocksfoot (S. 37 and S. 143 sown together) were compared in grazing and individual feeding experiments during the summer months of 1960, 1961 and 1962, using spring-born calves.

2. Herbage samples indicated that more grass was available to the animals grazing on ryegrass than on cocksfoot in 1961 but no differences were found in 1962. The ad lib. method of feeding should have ensured that quantity did not affect the results in the feeding experiments.
Effects of grass fallow treatments in restoring fertility of Buganda clay loam in South Uganda
Authors: Stephens D.
Published: March 2009

Between 1924 and 1934 Uganda, in common with many other African territories, tested arable rotations incorporating legumo green manures to maintain soil fertility (Martin, 1944; Uganda Dept., 1931–32) and it was concluded that the green manures failed to maintain fertility and were not worth the trouble involved. The Uganda Department of Agriculture accordingly changed its official rotations to modified forms of the indigenous shifting cultivation, namely 3 years of elephant grass rest alternating with 3 years of cropping. This same failure of green manures, combined with the apparent lack of correlation between crop yields and soil nutrient contents and the obvious deterioration of soil structure under crops, led Martin (1944) to the view that it was the physical not chemical condition of the soil which was important. Using his wet sieving technique he showed that, provided soils contained enough clay, all grass increased the water-stable crumbs over ½ mm diameter in the top soil and that 3 years under elephant grass was about optimal for restoring crumb structure.
The fleece of the Scottish Blackface sheep III. The relative importance of the fleece components
Authors: Doney J. M.
Published: March 2009

The relative importance of variation in the components of wool production to variation in wool production itself was estimated by two methods of analysis. About 30% of the attributable variation in total fleece weight was found to be due to variation in surface area and 70% was due to wool production per unit skin area. Between 50 and 60% of the variation amongst sheep in the latter character was found to be due to variation in fibre weight, the rest being attributed to variation in number of fibres per unit area (fibre density). The variation in mean fibre weight was further partitioned into 50 to 70% due to variation in mean cross-sectional area and the remainder to variation in mean fibre length.

Variation in wool production per unit skin area was also analysed according to growth period and position on the body. The results are discussed in relation to the partition of variance in wool production of other breeds.
The use of thein vitrofermentation technique to estimate the digestible energy content of some Egyptian forages I. Thein vitrodigestion of cellulose as a criterion of energy content
Authors: Naga M. M. A. , el-Shazly K.
Published: March 2009

Twelve digestibility trials were carried out using three adult rams on seven legumes and five nonlegume roughages.

In vitrofermentations were carried out over 24 hr. and the percentage cellulose digestion was determined. The whole rumen juice used to inoculate the fermentation tubes was obtained from a sheep with a permanent rumen fistula. Carbon dioxide was bubbled through during the fermentation run, unless otherwise indicated, to ensure anaerobic conditions.

The following significant correlations were calculated from the results:

In vivoandin vitrocellulose digestion for non-legumes:r= 0·93.

In vivocellulose digestion and D.E./kg. D.M. for non-legumes:r= 0·90.

In vitrocellulose digestion and D.E./kg. D.M. for non-legumes:r= 0·90.

In vitrocellulose digestion and D.E./kg. D.M. for non-legumes + alfalfa and cashrangeeg:r= 0·91.

In vitrocellulose digestion and D.E./kg. D.M. for all forages tested gave a highly significant correlation:r= 0·73.

In vitrocellulose digestion and D.E./kg. D.M. for legumes:r= −0·77.

Regression equations calculated for non-legumes and for all tested forages, when used for predicting D.E./kg. D.M. gave values which differed from the determined digestible energy by ± 8·70and ± 9·90% respectively. Applying Hershberger's regression equation to the present data, the D.E./kg. D.M. values differed by ± 8·69%.
The nutritive value of grasses grown in Uganda when fed to zebu cattle I. The relation between the percentage of crude protein and other nutrients
Authors: Bredon R. M. , Harker K. W. , Marshall B.
Published: March 2009

The use of the percentage of crude protein in grass consumed by cattle as a means of estimating the nutritive value of grass was investigated. Regression equations expressing the correlation between crude protein and the digestibility coefficients of crude protein, organic and dry matter were calculated.

A close correlation between the percentage of crude protein in faeces and in consumed grass was found, and a regression equation was calculated.
The productivity of five grass species at six levels of compound fertilizer application I. Dry-matter production
Authors: Henderson J. L. , Edwards R. S. , Hammerton J. L.
Published: March 2009

1. Data on the dry-matter production of five grass species (each sown with white clover), over the period 1954–56, at six levels of compound fertilizer application, are reported. Perennial ryegrass (S. 101), meadow fescue (S. 215), timothy (S. 48), cocksfoot (S. 26) and bent (N.Z. browntop) were sown in 1953 at appropriate seed rates, each with 2 lb. per acre S. 100 white clover. The fertilizer treatments were 0, 1, 3, 5, 7 and 9 cwt. per acre of a compound of composition 10% N, 4% P2O5 and 9·5% K2O, applied in the early spring of each of the years 1954–56. The swards were cut three times a year in 1954 and 1956, but only two cuts were possible in 1955.

2. The timothy mixture gave the highest total production of dry-matter over the 3 years, the bent and perennial rye-grass mixtures giving the lowest total productions. Differences between mixtures in annual yield varied in sign and in magnitude from year to year. For example, bent gave the lowest yield in 1954, but outyielded the meadow fescue and the cocksfoot mixtures in 1955, and the perennial rye-grass mixture in 1956. As regards the distribution of dry-matter production over the season, it was found that bent differed from the other mixtures in that a higher proportion of its annual yield was produced at the second and third cuts.

3. There were significant linear relationships of dry-matter yield to fertilizer application rate in most of the data. On average over the 3 years, 1·6 cwt. of dry-matter were produced for each cwt. of spring applied fertilizer in the first cut, 0·7 cwt. per cwt. of fertilizer in the second cut, while very small and non-significant responses were found in the third cut. There was no evidence of systematic differences between grass mixtures in response to fertilizer level.

4. The yield of clover dry-matter in 1956 (the third harvest year) was least from the cocksfoot and timothy swards, and was significantly and linearly depressed by fertilizer application in all three cuts.
A study of growth in swards of timothy and meadow fescue III. The effect of two levels of nitrogen under two cutting treatments
Authors: Lambert D. A.
Published: March 2009

1. Pure swards of S. 48 timothy and S. 215 meadow fescue receiving approximately 52 or 156 lb. N per acre over a period of 8 months were cut (a) at anthesis and twice thereafter or (6) every 4 weeks. The number and weight of tillers and leaves and annual plot yields were determined.

2. Tiller numbers rose to their highest in spring and then declined throughout the summer. The higher rate of nitrogen increased tillers in the meadow fescue more than in the timothy; the system of frequent defoliation resulted in enhanced production of tillers in the low nitrogen swards of both species, so that maximum populations within a species were similar under the two levels of nitrogen.
Nuclear magnetic resonance (NMR) micro-imaging of stems of Linum usitatissimum
Authors: McDougall G. J. , Goodman B. A. , Chudek J. A.
Published: March 2009

Nuclear magnetic resonance (NMR) micro-imaging techniques have been employed to study noninvasively the spatial distribution of mobile protons (1H) around the cotyledonary node of flax (Linum usitatissimum) plants of two differing growth morphologies. The gross anatomy of the tissues of the stem can be discerned as a result of differences in their mobile 1H contents. The technique produced excellent images of the complex changes in stem structure that occur at the point of origin of side shoots. Detailed structure within the xylem could be visualized and the presence of fibre bundles deduced as dark areas amongst tissues of higher 1H signal intensity.

As a result of the non-invasive and non-destructive nature of NMR-imaging, the images obtained have been compared to micrographs obtained by conventional histological techniques on the same plant tissue. In general, the two approaches produce comparable results, but the NMR images are influenced by the relaxation properties of the protons as well as their concentration. Paramagnetic species, such as Mn2+ ions, produce enhanced relaxation rates of protons in their vicinity and an apparent increase in proton density at short recycle times. Thus an NMR image can yield both chemical and structural information. Some of the advantages and disadvantages of this technique over conventional histological methods are discussed.
Irrigation and water use in leafless peas (Pisum sativum)
Authors: Silim S. N. , Hebblethwaite P. D. , Jones C.
Published: March 2009

Field trials at the University of Nottingham, UK, in 1979 and 1980 investigated the effect of moisture stress on the growth and yield of the leafless dried pea Filby. In the absence of drought, the crop photosynthetic area was increased and maturity delayed. Seed yield was increased by the production of a greater number of reproductive nodes and a reduced abortion of flowers and pods.

In the second season, two sowing dates were also tested. Later sowing reduced the seed yield under the high and low moisture treatments by 14 and 33% respectively, due to an increased abortion of flowers and pods. The high moisture treatment reduced the water use efficiency (WUE) in this season and WUE was lower for the later sown crops, but there was no effect on WUE in the previous season.

The seed yield and water use of pot-grown leafless peas were lower than were those of a nearisogenic line of leafed peas. Moisture stress reduced the yield of both phenotypes but the effect on the leafless pea was greater. Moisture stress imposed at flowering reduced yields more than it did at pod filling and there was an additive effect of moisture stress at both times.
The concentration of minerals in the blood of genetically diverse groups of sheep: II. Calcium, phosphorus, magnesium, potassium, sodium and chlorine concentrations for three hill-breeds and their crosses at pasture
Authors: Field A. C. , Wiener Gerald , Wood Jean
Published: March 2009

Three-hundred and thirty-four female sheep of the Blackface, Cheviot and Welsh Mountain breeds and the crosses among these breeds kept as one flock at pasture were bled in September 1966. Concentrations of Ca, Mg, K, Na and Cl were determined on plasma and P on whole blood. Mean concentrations (mg/100 ml) were: Ca 9·65; P 5·54; Mg 2·02; K 23·2; Na 345; Cl 365; and coefficients of variation (%) 11·1, 18·1, 29·0, 10·5 6·7 and 2·3 respectively.

Breed was a highly significant (P< 0·01) source of variation for Ca, P, Mg and Cl, but except for Mg, the contribution to the total variance was small (< 10 %). Average values for cross-bred ewes deviated significantly (P < 0–05) from those of pure-bred for Ca and P concentration. Live-weight, within class, had a small but significant effect on Ca and Mg concentration.

The concentration of Ca and Mg declined very significantly with age of ewe, there was a similar trend for K, while P showed a slight but steady tendency to increase with age, and Cl showed a more erratic increase.

For Ca, barren ewes had a lower concentration (– 0·44 mg/100 ml) than ewes with lambs whilst ewes with single lambs at birth had lower concentrations (– 0·35) than ewes with twins. Other factors with effects too large to be ignored (P< 0·1) were the interaction of breed x no. of lambs (K and Cl) and swayback history (Cl).
Urea supplementation of roughage-based diets for cattle
Authors: O'Donovan P. B.
Published: March 2009

Thirty-two growing bullocks were fed long barley straw ad libitum in each of three experiments; urea was added to the latter or to a diet of straw supplemented with either 1·36 or 2·72 kg meal. The amount of urea fed was 75 g per animal daily. In a fourth experiment, a basal allowance of 3·64 kg chopped hay was fed to thirty-two bullocks weighing 287 kg; in addition 4·55 kg of meal was fed in which none, one-half or all the supplemental nitrogen was supplied as urea. Rate of gain and straw intake of animals given straw only was similar to that of animals given straw and urea. Feeding 1·36 kg of either rolled barley or rolled barley supplemented with 10% soyabean meal, in addition to straw, did not elicit a response from urea. A response was obtained from urea when 2·72 kg of a barley–soyabean meal mixture was fed with straw. Blood urea concentrations generally reached a maximum at the third week of urea feeding and declined thereafter. Addition of urea to straw raised blood urea to about the same extent as incorporating urea with 1·36 kg of rolled barley. Blood concentrations were higher when the urea was fed with meal than when mixed with molasses. Nitrogen retention from urea was not significantly increased by feeding 1·36 kg of barley with straw ad libitum as compared to the retention on an all-straw ration. Slightly more nitrogen was retained when urea was added to rolled barley instead of a rolled barley–soyabean meal (10%) mixture. A ration of hay (3·64 kg) and 4·55 kg of barley promoted gains which were not significantly different from those of animals fed additional nitrogen as soyabean meal or urea. This indicates that the foregoing ration supplied enough nitrogen to meet the animals' requirement.
The feed intake of grazing sheep differing in age, breed, previous nutrition and live weight
Authors: Langlands J. P.
Published: March 2009

Two flocks of Merino wethers ranging in age from 3 to 87 months grazed a poor (L) or high (H) quality pasture for 3 months. The flocks were then combined, and intake was estimated while the sheep grazed four different pastures in succession. In a second experiment, flocks of Merino, Border Leicester, Southdown and Dorset Horn ewes of varying ages grazed in succession six pastures on which intakes were estimated and live weights recorded. The digestibility of the diet selected, as estimated from the faecal nitrogen concentration, declined with age by 0·053 units per month in Exp. (2) and curvilinearly in Exp. (1). In both experiments faecal output of sheep of similar breed receiving similar treatments increased with age to approximately 3 years and declined thereafter. In neither experiment was there a significant allometric relationship between intake and live weight.

The intake of the L group was consistently greater than that of the H group when both groups grazed together. The differences were correlated with the quantity of green feed available. The faecal output of Dorset Horns, Merinos, Southdowns and Border Leicesters at 28·7 months of age was calculated to be 451, 402, 346 and 588 g per day respectively in Exp. (2). Mean digestibility of the diet selected estimated by the faecal nitrogen procedure was 65·1, 63·0, 64·7 and 64·5 units at 28·7 months for the Dorset Horns, Merinos, Southdowns and Border Leicesters respectively. Differences between breeds in faecal output and in the digestibility of the diet were significant.
Metal contamination of soil in the Woburn Market-Garden experiment resulting from the application of sewage sludge
Authors: Riche H. H. Le
Published: March 2009

The Woburn Market-Garden experiment was started in 1942 to investigate the development of a market-garden type soil from an ordinary agricultural soil on light land by applying organic manures regularly. The ‘organics’ used were farmyard manure, sewage sludge, and composts of these with straw and farm waste. The use of sewage sludge was discontinued in 1961 and the yields of the crops up till then were published by Mann & Patterson (1963).
Effects of simplifying feeding methods for growing pigs by using a single ration throughout and by providing cereal and supplement components unmixed
Authors: Braude R. , Rowell J. G.
Published: March 2009

A co-ordinated trial has been carried out at sixteen centres to compare the following three feeding methods for growing pigs: (1) ‘sow and weaner’ type meal up to 120 lb live weight, followed by ‘finishing’ type meal to slaughter; (2) ‘sow and weaner’ type meal from start to slaughter; (3) as (2), but the cereal and supplement components given separately (not mixed).

Using the sow-and-weaner type meal throughout, rather than changing to a lower protein diet at 120 lb live weight, resulted in slight improvements (less than 2½%) in over-all growth rate and feed conversion; these improvements were not sufficient to compensate for the higher feed costs. None of the carcass measurements was significantly affected.

Lack of mixing of the cereal and supplement components did not harm the performance of the pigs and so farmers who produce their own cereals and buy concentrates may reduce costs by the elimination of mixing.
Some biochemical aspects of the preservation of buffalo semen
Authors: Srivastava P. N. , Raza Nasir M. M.
Published: March 2009

Initial pH of buffalo semen as measured electrometrically is 7.2 ± 0.025 and the buffering capacity 1.40 ± 0.026. Sulphamezathine in glucose–egg yolk–bicarbonate diluent depressed fructolysis in buffalo semen. This depression is considered to be a factor in the better maintenance of motility in this than in other media investigated. The more alkaline pH of this medium also appears to be beneficial in preserving motility on storage.
The effect of the time of application of nitrogen and potassium on the growth of the second early potato, variety Craig's Royal
Authors: Gunasena H. P. M. , Harris P. M.
Published: March 2009

The effect of time of application of nitrogen and potassium on the growth, development and yield of the second early variety Craig's Royal was studied by the technique of growth analysis. There was an indication that witholding nutrients led to the earlier initiation of tubers, but this was of no practical consequence and all treatments affected tuber bulking rate rather than the duration of bulking. Compared with early application, late application of nitrogen depressed tuber yield, although total drymatter yield was not affected. Late application of potassium, however, increased tuber yield; this was associated with an improvement in the recovery of applied potassium. Delaying the application of nitrogen also resulted in its more efficient recovery in the crop. Late application of potassium improved the recovery of early applied nitrogen and vice versa. Reasons are put forward to account for these effects.
Some effects of crop rotation on the productivity of crops on a red earth in a semi-arid tropical climate
Authors: Bennison R. H. , Evans D. D.
Published: March 2009

The yield of crops in the low rainfall areas of eastern Kenya has been shown to vary within each season according to the crops grown in preceding seasons. This phenomenon of crop sequence was associated more especially with the amount of soil nitrates remaining at all depths in the soil than with the amount of water that may be left. The quantity of nitrates left by a crop was generally related to its vegetative bulk, its rooting habit and duration on the ground, and increased as the crops were ranked in the order: local maize, short-term maize, silage maize, beans and fallow. The beneficial effect of a bean crop or a fallow was reflected in a third crop when the intermediate crop had a low nitrogen requirement.

The persistence of the relative differences in the nitrate levels in the soil would seem to be due to their low mobility under leaching.

The increase in yield of a crop was shown to be due to the more rapid development of the crop when nitrate supplies were more plentiful. When the duration of the rains was short the earlier, more abundant flowering resulting from the rapid growth gave better grain set, and hence greater and more reliable yields. When crops matured in dry weather the availability of soil nitrates at depths of up to 4 ft had a positive influence on yield.

Although rainfall was the main determinant of yield within each season, the use of fallowing to store water from one season to the next was inefficient. Similar amounts could be held in cropped land if late rains occurred. If early rains were plentiful the benefit of stored water could be lost by the thorough wetting of the soil profile.
A comparison between a method of jointing meat carcasses based upon their anatomical structure and a method based upon standardized butchering practice: II. Comparison of the uniformity of results
Authors: Williams D. R.
Published: March 2009

A standardized butcher-type method (B) in which anatomical reference points were used to determine cutting lines was compared with a semi-anatomical method (A) in which the jointing was based still more closely upon the anatomy of meat animals. Thirty-two lamb carcasses were split by hand sawing and the sides prepared for quartering, quartered and finally jointed into five hindquarter and five forequarter joints by one or other of two operators by either method A or method B according to a pre-arranged plan. Operator bias in the preparation of the sides for quartering was only noteworthy for the removal of internal fats.

Method A proved to be more consistent than method B, but the degree of advantage varied for different joints. In terms of the coefficients of variation for different joints by the two methods, method A had an advantage in consistency over method B for eight of the ten joints into which each side was divided.

The reproducibility of the semi-anatomical method (A) could be further improved by adopting more fully anatomical methods of joining.

The application and implications of an anatomical method in the excision of sample joints is noted.
An experiment comparing urea-formaldehyde fertilizer with ‘nitro-chalk’ for Italian ryegrass
Authors: Widdowson F. V. , Penny A. , Williams R. J. B.
Published: March 2009

1. Italian ryegrass was used in 1958 and in 1959 to compare ‘single’ spring dressings of urea-formaldehyde fertilizer (UF) with equivalent spring dressings of ‘Nitro-Chalk’ (NC), and with ‘repeated’ NC (divided equally between three cuttings). Barley measured residues in 1960.

2. At the first cut each year, yields from UF and repeated NC were similar, but later NC gave much larger yields. Aggregate increases from UF were less than half those from equivalent NC.

3. Both forma of nitrogen had residual value for grass and barley.

4. Maximum recovery of N, over 3 years, was 54% for UF and 90% for equivalent NC. Single NC dressings were recovered more completely than repeated dressings.

5. The maximum aggregate uptakes over 2 years by grass receiving 2·0 cwt. N/acre each year were 72 lb. P and 611 lb. K/acre.
The relationship between the cell-wall constituents of roughages and the digestibility of the organic matter
Authors: Gaillard Blanche D. E.
Published: March 2009

There is a strong correlation between the digestibility of the organic matter and the percentage crude fibre, percentage lignin, and percentage cellulose plus lignin in the foodstuffs examined.

There is evidence that the holocellulose and xylan in grasses are different from those in legumes in the extent to which they are digested. It is suggested that this is due mainly to the xylans or hemicellulose fraction in the forages, and may be a reflexion of a different molecular structure for the xylans in either group.

Within each group of plants both the holocellulose and xylan percentages are strongly correlated to the percentage digestible organic matter.

Excessive heating of hay led to a marked rise in the percentage lignin. This is probably due to the xylans becoming horny and insoluble, therefore being determined as lignin. This also offers an explanation for the decrease in digestibility of the organic matter.
Heat stress and development of the conceptus in domestic sheep
Authors: Alexander G. , Williams D.
Published: March 2009

In four series of experiments Merino ewes were exposed to ambient temperatures of about 44 °C and water vapour pressure of 33 mmHg for 9 h daily, and to 32 °C and 18 mmHg for the remaining 15 h daily, during the middle third, the final third or the final two-thirds of pregnancy. Birth weight and the weight of the placenta were considerably reduced by the treatments and the reductions were considerably more than could be accounted for by the partial loss of appetite produced by heating.

There was a close inverse relationship between birth weight and the elevated rectal temperature of heated ewes in several series; but the absence of foetal dwarfing in ewes with elevated rectal temperatures due to daily heating for only 9 h at 44 °C indicates that the elevated rectal temperature of the ewe is not the main cause of dwarfing.

Contrary to previous suggestions, the dwarfed lambs were not proportional miniatures, for the head components, the body lengths, the kidneys and adrenal glands were disproportionately large in heated lambs, while the liver, thyroid and thymus glands and the biceps femoris muscle were disproportionately small, and the ratio of secondary to primary wool fibres was very much reduced. There were cavities in the white matter of the cerebral hemispheres of heat-dwarfed lambs.

The hypothesis that foetal dwarfing is due to stunting of the placenta was examined, but conflicting evidence was obtained in the different series. However, it appears that under some circumstances a heat-stunted placenta is capable of considerable growth in the absence of heating during the final third of pregnancy, when the placenta is normally shrinking, and that placental shrinkage in late pregnancy may be greatly accelerated by the application of heat.

Neither thyroxine nor a preparation of ovine growth hormone, injected into heated ewes, prevented foetal dwarfing; the injections of growth hormone appeared to increase foetal mortality.
The effect of different stocking rates on the weight gain of Ankole steers on natural grassland in Western Uganda
Authors: Thornton D. D. , Harrington G. N.
Published: March 2009

Stocking rates of 3, 6 and 9 acres per 2- to 3-year old steer on Acacia-Cymbopogonj Themeda complex pasture in Ankole, Uganda, demonstrated that 3 acres per head gave significantly lower individual live-weight gains, but that there was little difference between 6 and 9 acres over a 6-year period. Although cattle grazed at 3 acres averaged only 175 lb per head per annum, compared with 207 lb at 6 acres per head, the income was Sh. 34 per acre compared to only Sh. 20–50 at 6 acres per head. At 9 acres/head the return was Sh. 13–50 an acre.

A comparison of a 2 paddock/1 herd system with continuous grazing revealed no differences in production, despite the heavier capital investment involved in the former system. Growth rates at all three stocking rates were similar for most of the year, but in the dry season when all the cattle lost weight those stocked at 3 acres per head suffered the greatest losses (50–60 lb) and those at 9 acres per head the least (20–30 lb).
Some preliminary observations on the nature of factors influencing the excretion of non-dietary faecal nitrogen by ruminant animals
Authors: Mason V. C.
Published: March 2009

1. When roughage rations of medium to high quality were given to steers and aduit sheep, the excretion of non-dietary faecal nitrogen was positively related to the intake of truly digestible dry matter. In these experiments no significant relationships were noted between non-dietary faecal nitrogen excretion and the intake of either truly digestible nitrogen or truly indigestible dry matter.

2. When concentrate rations containing 1.6–3.2% nitrogen were given to lambs weighing 19–27 kg the excretion of non-dietary faecal nitrogen was positively and significantly related to the intake of both truly digestible dry matter and truly indigestible dry matter, but not related to the amount of truly digestible nitrogen consumed.

3. Grinding and pelleting a grass ration for steers resulted in an increase in the excretion of non-dietary faecal nitrogen and bacterial + endogenous debris nitrogen, of 28 and 30% respectively, compared with the chopped material.

4. It is concluded that these responses reflect the dominating influence of nitrogen of microbial residues from the rumen and hind-gut on the excretion of bacterial + endogenous debris nitrogen and non-dietary faecal nitrogen.
Early reproductive failure of ewes in a hot environment IV. The ovary
Authors: Ryle Margaret
Published: March 2009

1. A balanced factorial experiment was carried out with 48 Merino ewes. There were two levels of each of the four factors: environmental temperature, thyroxine status, vitamin A intake and progesterone status. Each ewe was killed at 25 days' pregnancy. The ovaries were removed, weighed and examined histologically.

2. There were no significant treatment effects on ovarian weight, corpus luteum diameter, lutein cell frequency, lutein cell nuclear diameter, the number of Graafian follicles exceeding 0·9 or 1·9 mm. diameter, or mean follicle diameter. The results suggest that with more animals heat might prove to depress ovarian weight and vitamin A to increase ovarian weight, corpus luteum diameter and the number of large follicles.

3. There were no significant differences between the mean values for those ewes with live embryos and those with dead ones with respect to any of the above indices.

4. The results support the conclusion that variations in embryonic viability due to the experimental treatments were not mediated primarily through variations in ovarian hormone secretion.