On the adoption of a sampling method for the estimation of the yield of small experimental plots, the need arose for a threshing machine capable of threshing quickly and accurately the small sampling-units which comprise the sample from an individual plot. These sampling-units contain various numbers of ears from some three or four to twenty or more, and there is no commercial machine which deals adequately with such small quantities of grain. The number of sampling-units from a typical randomised block experiment may amount to 2500, and to thresh and winnow such numbers in two distinct operations would take no inconsiderable time. As a direct result of this, a machine was constructed in which these two operations were successively performed, without the need of handling the intermediate products. It is the object of this paper to describe this machine and the manner in which it was used for this purpose at Rothamsted last season. Wheat, oats and barley were treated, only minor alterations of the size of the screens, the speed of rotation and the strength of the blast for the separation of the chaff being necessary.

The aim of this investigation was to grow barley as a fodder crop under highly saline conditions. Saline irrigation waters with an electrical conductivity (EC) of 2·5, 4·0, 6·0 and 8·0 mmhos/cm respectively were used to irrigate test crops of barley over two growing seasons.

It was concluded that in general more highly saline water leads to a considerable increase in soil salinity even over a short period of growth, and a close control of soil salinity through leaching is required. Saline water with an EC of 4·0 mmhos/cm may be utilized without excessively high yield reductions if the soil salinity is well maintained. The saline waters with an EC of 6·0 mmhos/cm and 8·0 mmhos/cm may lead to yield reduction, and they require careful managmeent to control soil salinity build-up.

Over three grazing seasons a sward of perennial ryegrass, cv. Gremie, was grazed on a rotational paddock system by growing beef cattle weighing on average 185·5 kg when turned out to grass in April. Six grazing treatments were compared: grazing at 20- or 35-day intervals at each of three herbage allowances of 5·3, 4·3 and 3·3 kg grass D.M./100 kg live weight (4·0, 3·2 and 2·4 kg D.M./IOO kg live weight in the 1st year).

Measurements of net herbage accumulation and herbage consumption throughout each grazing season were made by taking grass sampling clips to ground level before and after grazing. Animal live-weight gain was assessed by regression on weighings of stock taken either every 7 or every 4 days depending on regrowth interval treatment. Adjustment of allocation treatment was made by varying the weight of stock grazing on a fixed paddock area.

In no year did annual net herbage organic-matter accumulation (NHA) differ significantly according to length of grazing interval. NHA showed a 4·7 % advantage for the longer interval in the first 2 years which changed to a deficit of 4·1 % in the final year of the experiment. Herbage allowance treatment produced no significant effect on NHA in any year. The interaction effect of herbage allowance and grazing interval was not significant.

Herbage consumption was greater in 2 years out of three under the 20-day regrowth period than with the 35-day treatment, although average degree of defoliation was slightly greater (44·0 v. 38·4%) with the longer interval.

Animal live-weight gain was significantly (P < 0·05) affected by herbage allowance in all 3 years; decreasing herbage allowance generally resulted in reduced live-weight gain. Only in 1 year was there a significant difference (P < 0·001) in live-weight gain with the different rotation length treatments.

Various carcass measurements were obtained from 216 Hereford steers and evaluated in an attempt to find traits or combinations of traits which accurately estimate carcass composition. Carcass weight and trimmed retail cuts from the round proved to be the best single estimators of kilograms of retail cuts. Prediction equations were developed using carcass weight, trimmed retail cuts from the round, longissimus dorsi area, measures of fat thickness at the 12th rib, untrimmed round weight and weight of kidney, heart and pelvic fat in various combinations. Eighty-four to 94 % of the total variation in actual kilograms of retail cuts could be accounted for by using these equations.

The use of town stable manure enters so largely into the economy of farms, and especially market-gardens, situated within fairly easy distance of London or other large cities, that it is somewhat curious that but little information has been published in this country as to its chemical composition. In fact, with the exception of a couple of analyses made by myself as long ago as 1889, which were published at the time in the Mark Lane Express, and subsequently reprinted in Aikman's book on “Manures and Manuring,” I do not remember to have seen any analyses of London manure. The samples which were the subject of these analyses were collected from a very limited number of stables, some of which were littered with peat moss and others with straw, the object at the moment being to compare the manure produced with the two kinds of litter. I have more recently however made some fairly full analyses of two more representative samples of London manure, but before proceeding to give these it may be desirable to reprint in this place, for future reference, the old analyses just mentioned.

1. Symptoms of zinc deficiency and toxicity have been studied in guar, brinjal, maize, tobacco and Mosambi (Mozambique) using a sand-culture technique.

2. In zinc-deficient guar plants, depressed vegetative growth and smaller leaves than normal ones were found. Only few flower buds were seen, and there was abscission of leaves at the time of flowering.

3. Chlorosis followed by necrosis and finally the drying up of leaves was the most characteristic deficiency symptom in the case of brinjal; growth was stunted and flowers failed to set fruits.

4. In the newer leaves of maize, intermittent light yellow bands were formed just parallel to the midrib.

5. In the lower leaves of tobacco, chlorosis followed by necrosis was observed; growth was stunted and leaves were small in size.

6. In Mosambi (Mozambique), whitish yellow patches in between the veins were observed; leaves were small, pointed and quite unhealthy.

7. There was an increase in zinc uptake with increased rates of application of zinc.

8. Crude protein increased with increasing zinc supply up to levels beyond the optimum for growth.

Keen and Coutts(8) and Coutts(1) have suggested that the percentage of water in a soil at the sticky point is related to the colloidal content of the soil, as measured by “loss on ignition,” in the following manner:

S = mI + c,

i.e. by a rectilinear equation, and point out that the figure obtained for c approximates to the theoretical percentage of water held in the interstitial spaces of an ideal soil.

This group, which is concerned with the applications of mathematics to agricultural science, was formed in 1970 and has since met at approximately yearly intervals in London for one-day meetings. The thirty-eighth meeting of the group, chaired by Professor A. Kassam of the University of Reading, was held in the Kohn Centre at the Royal Society, 6 Carlton House Terrace, London on Friday, 31 March 2006 when the following papers were read.

In comparing the moisture contents of soils in the field, material precision is to be gained if the sticky points are also determined and the comparison based on the difference between the two values. There is a high degree of correlation between the moisture contents and sticky points of soils in moisture equilibrium with each other.

Besides retarding somatic development, hypophysectomy markedly increases the deposition of subcutaneous fat in foetal lambs (Liggins & Kennedy, 1968). Two hypophysectomized (HX) and two pituitary stalk-sectioned (SX) foetuses became available for dissection during a study of the growth of normal Romney sheep (Broad & Davies, 1980a, b and unpublished). The present report supplements the existing information concerning the effects of altered hypophyseal function on the carcass composition of foetal lambs (Liggins & Kennedy, 1968; Alexander, 1978).

A study using 1150 lambs to estimate genetic and phenotypic parameters of some weight and fleece traits was carried out on coarse-wool Barki sheep. The weight traits were birth, weaning, yearling weights and daily gains whereas fleece traits included kemp score, staple length and greasy-fleece weight.

Heritability estimates of weight traits were within the range 0·25–0·30. Those of fleece traits were 0·16, 0·21 and 0·43. The repeatability estimates of fleece traits were 0·18, 0·38 and 0·53 for staple length, greasy-fleece weight and kemp score respectively.

Phenotypic correlations between body weight and fleece traits were mostly positive. Genetic correlations between greasy-fleece weight and body weights were mostly positive and of medium values. Those between kemp score and body weights were mostly negative, ranging from medium-high to high.

Two experiments were carried out to investigate how milking in mid-line (ML) affects the lipolysis level and milk composition in goat livestock, in comparison with low-line (LL) milking. The first experiment took place, in triplicate, on an experimental farm. For each replicate, a crossover design (62 goats, two treatments, ML and LL, in two periods each lasting 4 days) was used. Milk samples were taken daily at 0 and 24 h after milking. In the first experimental replicate, some enzymatic coagulation cheeses were made, which were assessed by a panel of tasters at 50 and 100 days of maturation. In the second experiment, the lipolysis level and composition of tank milk from 55 commercial dairy goat farms (25 ML and 30 LL) were analysed, in milk samples taken in three different weeks. The results of the first experiment showed that ML milking increased free fatty acid (FFA) concentration in raw goat's milk significantly (0.71 v. 0.40 mmol/l, respectively). However, in the milk samples taken from commercial farms the FFA concentration remained unaffected by the milking pipeline height (0.59 v. 0.58 mmol/l for ML and LL, respectively). No significant differences were found in the milk composition, nor in the sensory characteristics in the cured cheeses, which suggests that factors other than the milkline height are able to influence the level of lipolysis under commercial conditions. Therefore, ML milking should not be discouraged, provided that the correct functioning and management of the milking operation and milk storage on the farm is guaranteed.

Blood potassium and haemoglobin types were investigated in three breeds of sheep in India. Both high and low blood potassium types and all three haemoglobin types—A, B, and AB—were found to be present in two of the breeds examined, namely Bikaneri and Corriedale x Bikaneri. Mandia sheep had both potassium types but only two haemoglobin types—B and AB. Haemoglobin B and high potassium types predominated in all the three breeds; this would clearly point to the comparative suitability of these animals for relatively drier parts of India.

The Agricultural and Related Industries Study Group of the Operational Research Society held a one-day meeting on ‘Decision Support Systems for Profitable Livestock Production’ on 18 November 1992 at the Meat and Livestock Commission, Milton Keynes, UK. The Group promotes the use of the scientific method in solving management problems. The aim of the meeting was to look at the contribution of advances in modelling towards improving management and hence profitability in livestock production. The first four papers concerned feeding and the remaining two breeding. A large part of the discussion could perhaps best be summed up by the regression equation which related dry matter intake and waste output from a cow. When the output was zero, the intake was reduced by 50%!

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

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

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

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

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

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

In ⅜ Merino primary centrals produced halo hairs, super sickle (A, A′, B), primary laterals grew super sickle (A, A′, B), sickles, medium curly tips, and secondaries produced medium and fine curly tips and histerotrichs.

The Papaya tree is common in all parts of India and is grown also in the Philippine Islands, Federated Malay States, Java, Ceylon, and other tropical countries.

Three field trials with Italian ryegrass showed that solid N fertilizers usually gave larger yields than solutions containing 5% N but the differences were significant in only three of thirteen comparisons. More N was taken up from solid fertilizers than from solutions; the differences were not significant at 561b N/acre but were at 1121b N/acre. Grass given solutions had smaller percentage of N and the differences in the percentage of N were significant in eight of ten comparisons. In pot experiments with Italian ryegrass, solutions containing 3.3% N were less effective than solid fertilizers, but solutions containing 1.8% N were equally effective. Possible causes of solutions being less effective are discussed.