The effect of rainfall, sowing date and yield on the percentage of nitrogen in the barley grain of certain representative plots on Hoosfield is studied.

All these factors are shown to have marked effects. The farmyard manure plot differs from the others, both in mean percentage and in the effects of rainfall and yield.

Changes in variety appear to have had little apparent influence, but there is a progressive decrease in the percentage of nitrogen which cannot be accounted for by changes in any of the above factors, and which may well be due to varietal improvement

Comparison is made with the results of the similar study on the permanent barley plots at Woburn.

Two objectives were in view in undertaking this research.; to ascertain the cost in energy of muscular work in the goat and to investigate the adaptability of the Douglas-Haldane method of indirect calorimetry to work experiments on this animal. It is to the results of human experiments chiefly, that the present position of the physiology of muscular exercise is due which owes comparatively little to experiments on other animals. Zuntz and his school (1) have, however, compared the effect of a fixed amount of work on men, horses and dogs, and Lusk (2) has carried out some investigations into the influence of work on the dog. The principal obstacle hitherto in the way of employing animals other than man for work investigations has been the want of a sufficiently adaptable technique. Zuntz's experiments on the horse were conducted by means of a tracheal cannula, a device that, though fairly adaptable for work experiments, is not always desirable. Lusk's experiments were carried out in his respiration calorimeter where the applicability was very limited. Boothby and Sandiford(3) and Kunde(4) have carried out metabolic investigations on dogs by means of the Benedict apparatus, but here again the device is only of limited value for work experiments, which none of these workers have apparently yet undertaken. It was believed therefore that, if the proposed experiments were a success, in addition to possessing a certain physiological value, they would open up a wide field of research of great practical significance.

An insignificant short-term increase in the natural dose of ionizing radiation during the embryogenesis period is beneficial not only for the embryonic development of the chicks, but also for their postembryonic growth and development as well as the egg production of the pullets.

Irradiation of incubated eggs with microdoses of radioactive radiations is another possibility for the utilization of atomic energy bringing about an improvement in the economically useful properties of poultry.

The starchy seeds of jackfruit (Artocarpus heterophyllus Lam.) contain 124 g crude protein and 740 g total carbohydrates per kg. The possible replacement value of jackseed meal (JSM) for maize in chick diets was evaluated in Peradeniya, Sri Lanka between 1986 and 1989. In Expt 1, the inclusion of 125 and 250 g raw JSM/kg diet severely depressed growth performance and increased mortality in chicks. Organ weights, relative to body weight, were also affected in chicks fed on diets containing 250 g raw JSM/kg diet. Subsequent analyses revealed lectins and trypsin inhibitors to be responsible for the toxic effects of raw JSM. Processing of JSM by moist-heat treatment completely destroyed these antinutritional factors. This was demonstrated by the results of Expt 2, where the feeding value of processed JSM was found to be comparable to that of maize up to 250 g/kg diet. Moist-heat treatment also improved the in vitro protein digestibility (56·7 v. 84·2%) and apparent metabolizable energy (8·97 v. 13·72 MJ/kg) values of JSM. In Expt 3, the inclusion of 500 g processed JSM/kg diet resulted in reduced broiler performance and lowered the apparent dry matter digestibility and apparent energy utilization of the diets. The non-starch polysaccharide component of the JSM may have been responsible for these negative effects.

The main findings of the present trials may be. summarized as follows:

(1) When ‘mineralized’, cooked potatoes are fed as the bulky supplemental food in the Lehmann system of pig-feeding, and the basal meal allowance is restricted to 3 lb. per head per day, bacon pigs are able to make as good progress, in respect both of rate of live-weight increase and economy of food conversion, and at every stage from 60 to 200 lb. live weight, as they would if kept on a diet composed wholly of balanced meal. In the present trials, pigs of about 200 lb. live weight were able to consume 15–17 lb. of cooked potatoes per day in addition to the daily allowance of 3 lb. of meal. It required, on an average, about 1030 lb. of cooked potatoes and 311 lb. of balanced meal per pig to fatten the animals from 60 to 200 lb. live weight. The cooked potatoes, when assessed on the air-dry standard of 13 % moisture, were able to replace the balanced meal on a lb. for lb. basis without detriment to the progress of the pigs, and the average saving of meal thus made possible amounted to about 225 lb. per pig, or 38·2 % of the total meal consumed per pig on the control, all-meal diet.

(2) Cooked potatoes should be introduced into the ration gradually and the allowance should be scaled according to live weight in the manner adopted in the present trials. When the amount to be fed is large, it is best to feed ‘mineralized’, cooked potatoes only during the morning and to place the basal meal in the trough towards the end of the afternoon.

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.

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.

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.

An account is given of methods which have been employed in laboratory and field studies of the actions of rolls on the soil. These studies have revealed little that is remarkable or unexpected concerning the actions of rolls on the soil, but they have clearly demonstrated that the exact actions of rolls differ widely according to the circumstances in which they are employed. When rolling is carried out in field experiments, it is necessary to perform tests to measure the exact effects produced on the soil. In this way it should gradually become more apparent when and how rolling is likely to be beneficial.

Of the methods which have been described, the last two, viz. tests of the consolidation, moisture content and tilth by means of a sampling tube, and of the mechanical resistance to the penetration of a probe with the automatic “resistance” recorder, are well adapted to use in field experiments. These methods are being used in many field experiments involving cultivations, and it is hoped that it may at some time in the future be possible by such methods to relate cultivations and crop yields through a knowledge of the soil structure.

It is now generally recognized that the pH of a silage is the best single criterion of its quality. In other words, it is regarded as the best single guide to the type of fermentation that has taken place in the mass in the silo and thus serves to indicate the degree of success achieved in the ensilage process, whatever the crop or its stage of growth. For instance, in the case of silages, made with or without molasses, where the pH is at or below 4·0, the silage would be deemed to be of ‘excellent’ quality, that at 4·0-4·5 would be designated ‘good’, that at 4·5–5·0 only ‘moderate’, and at or above the latter figure the silage would be classified as ‘bad’. To get a complete picture of the chemical changes that have taken place and to assess the feeding value of a silage is quite a different matter and is not the object of the present note.

Individual muscles, individual bones and fat depots from the non-carcass parts (head, foreshanks and tail) of 40 steers (chilled carcass weight 142–174 kg) were studied in an attempt to predict carcass composition more accurately than in an earlier study where the crude non-carcass parts, head, tongue, foreshanks and hindshanks were used.

The technique did not improve the accuracy of prediction of muscle or bone. Carcass fat, which was calculated by difference in the earlier study, was predicted more accurately using intermandibular fat weight (requiring 3–4 min to obtain) plus fat thickness at the 12th rib. However, the accuracy of this prediction (carcass fatness range 14·0–33·6%, residual standard deviation 1·98%) was no greater than that using chilled side weight plus fat thickness at the 12th rib.

Careful dissection and trimming of anatomical entities from the non-carcass parts therefore offered a slight advantage only in the prediction of carcass components over existing techniques.

Substitution of hot side weight for chilled side weight, and sacral crest fat thickness for fat thickness at the 12th rib did not lead to a loss in the accuracy of prediction of muscle, bone or fat.

Lactating Boran type zebu cows had high haemoglobin levels during the week after calving, after which these levels dropped sharply and then continued to decline more gradually until their calves were weaned. Some recovery was made during the subsequent dry period.

Cows fed 1 oz. dicalcium phosphate daily were constantly lower in blood haemoglobin level than their controls, and significantly so between the 14th and 20th weeks of the lactation. No differences were observed in weekly weight changes or in estimated milk yields.

Calf haemoglobins decreased gradually with age until relatively adult levels were reached at about a year of age. Initial content during the week of birth was lower than at a few weeks old. There was no difference in the blood haemoglobins of calves suckling on treated and untreated cows.

Individual variation was high in all groups. Some implications of seasonal effects and altitude are discussed.

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.

A uniformity trial on groundnuts has been analysed and the results discussed. Plant number is less variable than yield and less sensitive to shape of plot and of block. For yield, long narrow plots are more efficient than shorter and wider plots, in all shapes and sizes of blocks and in Latin squares. The plots should not be arranged end to end along the contours, but side by side, either singly or in pairs, forming compact blocks.

The regression of the plot variance of the mean yield per unit area on size of plot approximately follows a linear logarithmic relationship. A similar relationship holds for plant number. The value of the regression coefficient b′ is low and it has been shown that, as expected, there is considerable gain from the use of small blocks. The efficiencies of various confounded and incomplete block designs relative to designs in larger blocks have been determined for some particular layouts, and values for other layouts, ignoring shape of plots and of blocks, have been obtained by interpolation.

The field used for this uniformity trial appears equally variable in all directions.

Carcass yield and chemical composition of edible meat of fifteen fattened yearling rams and fifteen fattened yearling wethers of Sudan Desert sheep were studied. The animals studied were random samples from groups which had been fattened for 2 months on three different rations. They were about 14 months old at slaughter, and their weights at slaughter ranged from 25 to 52 kg. The average dressing percentage for rams and wethers was 53·0 and 52·2% respectively. Warm carcass weights were 20·22 kg for rams and 19·64 kg for wethers, and these carcasses lost 4·2 and 3·1% of their weight respectively, after 48 h storage in the cold room at 0°C. The bone content of carcasses of rams and wethers was 23·4 and 21·3% respectively. The longissimus dorsi ‘loin eye’ area at the 12th rib was 8·6 cm2 and 8·3 cm2 for rams and wethers. The proportions of wholesale cuts in ram and wether carcasses were comparable, whereas the proportions of slaughter by-products varied between the two ‘sexes’. Mean weight of kidney fat in wethers was 50% greater than in intact rams, but the mesenteric and caul fat was heavier in rams than in wethers.

Ram carcasses had higher specific gravity than those of wether carcasses. Specific gravity was negatively correlated with fat content and positively correlated with protein, moisture and ash content of the edible meat of the carcass. The regression equations relating specific gravity to the major chemical components of meat had too high standard errors to be of predictive value in a practical sense.

Soya beans grown on land planted the previous year with inoculated soya beans produced more nodules, lodging, seed yield, 1000 seed weight, and protein content and less seed oil concentration as compared to those grown on land that was planted with non-inoculated soya beans. Nitrogen fertilization (120kg N/ha) reduced the total number of nodules per plant. Increasing inoculation rates of the seed increased the dry weight of nodules per plant. Location, nitrogen fertilization, and inoculation increased or decreased the levels of certain amino acids but had no significant effect on the sulphur amino acids, cystine and methionine.

In an earlier paper the estimation of the total digestible nutrients (T.d.n.) to be expected in ruminant feedingstuffs has been described (Glover, J. Duthie, D. W. & Dougall, H. W. 1960). In a like manner the average T.d.n. in pig feeds can be estimated. The necessary equations have been obtained in earlier papers (Glover & Duthie, 1958A, b). They are, respectively

where C.p. and C.f. are percentage crude protein and crude fibre, respectively, in the dry matter of the feed, D.c.p. is digestible crude protein and N.r. the nutritive ratio. They can be used directly for the estimation of T.d.n. because by definition T.d.n. is D.c.p.(N.r. + 1); thus the T.d.n. to be expected at different levels of C.p. and C.f. can readily be calculated. Table 1 shows in abbreviated form some of the values that are obtained in the ranges 0–30% C.p. and 0–40% C.f., while Fig. 1 illustrates in detail the effect on T.d.n. of changing C.p. and C.f. levels of the diet. This figure shows clearly the very marked effect of increasing C.f. depressing the digestibility of the total nutrients in pig feeds, a fact which is already well known.

Greasy fleece weight (12 months growth) and wool samples from hip and shoulder regions were taken on 15 Dorset, 20 Leicester, 20 Suffolk and 17 DLS ewes (a cross of ½ Dorset, ¼ Leicester, ¼ Suffolk obtained by mating DL rams to DS ewes and DS rams to DL ewes). The purpose of the study was to compare wool production and characteristics of the first generation of DLS with that of the three breeds of origin. Wool production of DLS was 3·58 kg, 8·8 and 14% higher than that of Suffolk and Dorset, but 11% lower than that of Leicester (P< 0·01). The percentage of clean wool was highest in Leicester (78·3%), followed by DLS, Dorset and Suffolk (76·1, 74·3 and 70·5%, respectively). The average fibre diameter of the DLS and Leicester was 38 /m, 4 /m thicker than that for Suffolk and Dorset (P < 0·01). Average fibre length was 15 cm in DLS and Dorset, 6 cm shorter than in Leicester, and 3 cm longer than in Suffolk (P < 0·01). The variability in fibre diameter and length was highest in Leicester, followed closely by DLS.

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.