Transfer was made of 2958 sheep ovarian oocytes, cultured in growth medium for 24–30 h, to the oviducts of 142 oestrous sheep; 132 were bred and ten remained unbred. Forty-two per cent of oocytes were recovered, mainly 4–24 h after transfer; tubal flushings were examined for sperm. Evidence of a sperm within the vitellus of follicular oocytes was found in nine recipients, the earliest at 6 h 50 min after transfer. Pronucleate eggs were most frequent 9–14 h after transfer; a limited number of eggs showing normal cleavage wasrecovered.

The experiments described in the following pages were made with a view to discover how far purely physical and chemical processes, known to take place in the soil, may be expected to give rise to nitrites and nitrates. Scattered throughout the extensive literature on nitrification are occasional papers tending to show, what might also be expected on theoretical grounds, that non-bacterial processes may be important sources of nitrates. Formerly these processes were considered to be the only sources, then came the brilliant researches of Schloesing and Muntz, Warington, Winogradsky, and others on nitrifying organisms, and non-bacterial processes were forced into the background. Now that a full knowledge of the various sources of nitrogen compounds in the soil has become so indispensable to the agriculturist, it seemed desirable to make a careful examination of the various chemical and physical processes known to take place in the soil, and to ascertain whether they make any direct or indirect contribution to its stores of nitrates. To this end we have repeated and extended such of the recorded observations bearing on the subject as seemed to merit repetition; we have also devised other experiments to make the examination as complete as possible.

Zinc deficiency is a common nutritional problem in calcareous agricultural soils, resulting in reduced crop yield and performance. The effects of zinc sulphate (0 and 40 kg/ha) on seed yield, its components and seed element contents of 21 wheat cultivars were investigated. Zinc sulphate application increased plant height, leaf area index (LAI), flag leaf area, biomass, spike length, number of seeds per spike, seed weight and harvest index (HI). The increase in HI indicates the greater effect of zinc on seed production compared to plant biomass. In most of the cultivars, zinc sulphate application decreased the content of phosphorus and nitrogen in seeds and increased the content of iron and potassium. The cultivars showed significant differences in all the traits measured, indicating the existence of genetic diversity in the cultivars studied. In the second year, which was hotter and drier than the first year, zinc sulphate application reduced the damage caused by drought and heat stress and improved seed yield and quality. The regression fit showed that newer cultivars had lower yields in unfertilized conditions compared to old cultivars and showed their superiority in zinc fertilized conditions. It seems that the newer varieties require more fertilizer because they have been bred on fertile soils.

The soil used in this experiment was a sandy clay low in phosphorus and in nitrogen from the College Farm. A (3 x 3 x 2) factorial experiment with three replications using an upland rice variety, Agbede, was carried out in the open on the College Farm between January and May 1963. Ten-litre plastic buckets 25 cm. deep and holding 11 kg. of soil, which was thoroughly mixed and the pH brought to 6.0 by liming, were used in growing the plants. These buckets were left standing on the ground, and there was no rain during the experimental period.

This paper is a record of the composition of the milk of an abnormal cow, during a period extending over three lactations. Although this cow was found eventually to be suffering from tuberculosis of the udder and lungs, no signs of the disease were apparent during the first two lactations recorded.

The milk produced by this cow was abnormal during the whole period under review. Fat percentages were very variable, but the solids not fat content was consistently low, only 2 per cent. of the total number of samples analysed exceeding 8·5 per cent. in this constituent. Protein and lactose percentages were much below the averages for normal milk, but in the case of total ash the mean figures were normal. Of the ash constituents, the soluble portion was very high and the insoluble portion correspondingly low, the former presumably indicating a high chloride content. The percentages of phosphoric acid and lime were considerably below the mean figures for normal milk.

Lactose and soluble ash percentages show a marked negative correlation, and moreover support the contention of Porcher and others that a definite lactose-chlorine ratio exists in milk.

It is suggested that an abnormally low solids not fat content (i.e. low protein and lactose) and abnormal percentages of the individual ash constituents may be a sign of incipient disease affecting the organs involved in the secretion of milk.

Four inexperienced operators used a Smith's Essem Metatest ultrasonic grader and a Philips Sonatest instrument to estimate the thickness of tissue overlying the M. longissimus dorsi at three sites over the tenth intercostal space of live steers. They also measured skin fold thickness over the central site using a micrometer. Suprafascial (selvedge) and total carcass fat were measured at corresponding sites on the chilled carcasses.

The residual standard deviations from multiple and simple regressions of suprafascial and total carcass fat thickness on the ultrasonic readings of different operators, using both instruments over the three sites with and without a measurement of skin thickness were compared.

The following conclusions were drawn. Use of a constant distance from the midline of the live animal to locate the site for ultrasonic point measurement would lead to errors in estimating fat thickness at a specific anatomical location. If the edge of the M. 1. dorsi is palpated to locate the measurement site, estimates of carcass fat thickness with a residual standard deviation of 2·5 mm are possible by relatively inexperienced operators using single point reading ultrasonic instruments. Fat deposition between the fascial sheath and the underlying M. 1. dorsi is a source of inaccuracy when estimating carcass fat cover particularly at sites closer to the midline and on fatter animals.

Using the Metatest instrument, fat cover could bo estimated in the live animal with an accuracy similar to that reported by other workers using the Scanogram. Using the Sonatest instrument the estimates were generally slightly less accurate especially at the most lateral site. Inclusion of a measurement of skin thickness gave a very slight but consistent improvement in accuracy of estimation of carcass fat cover.

(1) Animals on a calcium-deficient diet suffer periodically from loss of appetite though the ration is in every other respect satisfactory.

(2) The results of twenty-two digestion trials show no enhanced effect on the digestibility of the organic constituents of the food on adding calcium carbonate to a lime-deficient ration.

In conclusion, I wish to express my thanks to Prof. T. B. Wood, F.R.S., for giving me the necessary facilities to carry out the work; to Mr H. R. Davidson, M.A., for placing the experimental animals at my disposal and also to Dr H. E. Woodman for his active interest and supervision at all stages of the work.

From a mixed group of cross-bred steers slaughtered at the same age, up to 12 carcasses of similar weight from each of the five conformation classes were chosen using the European Economic Community (EEC) scale for the classification of carcasses of adult bovine animals. In the hindquarter of carcasses with better conformation the ratio of muscle to bone was higher with less internal fat and more subcutaneous fat, muscles were heavier and blockier, both the carcass and leg length were shorter. Short-thick muscles were associated with short-thick bones. The results indicate that the EEC scale is a useful method to discriminate between carcasses differing in composition. It is suggested that differences in muscle: bone ratio in cattle could reflect differences in the structure and shape of bones. The conclusions remain tentative until they are confirmed on a larger number of carcasses.

(1) The solubility of the potash in 34 soil samples from 13 soils typical of large areas in the East of Scotland has been determined by the methods of chemical analysis using (a) hot concentrated hydrochloric acid, and (b) 1 per cent, citric acid solution, and the values obtained compared with the quantities of potash existing in the exchangeable form. The total mineral potash has been determined for six samples and Neubauer's method of analysis has been applied to 10 samples and again compared with the exchangeable potash.

(2) The average value of the total mineral potash in the soils examined was 2·04 per cent., which indicates the presence of comparatively large reserves of potash in these soils. No relation was found to exist between the total potash, and the quantities soluble in hot concentrated hydrochloric acid.

(3) The average value of the HCl-soluble potash was 0·50 per cent, and in the profile samples there was generally an increase in solubility with increase in depth of soil.

1. A series of experiments, involving the use of three hundred and forty Rhode Island Red x Light Sussex day-old cockerels, was carried out to determine (a) the influence of floor type on the incidence of perosis, and (b) a method of lowering the high incidence of perosis which may occur when chicks are fed the experimental diet no. 124 originally described by Dam et al. (1951).

2. It was found that the incidence of perosis was about 60% higher in groups of chicks raised on wiremesh floors than in groups of chicks similarly raised on wooden floors.

3. Neither the area of the floor space nor the level of manganese in the diet influenced the incidence of perosis.

4. When the calculated choline content of the diet was 500 mg./kg. the incidence of perosis was 60% but when it was raised to above 800 mg./kg. the incidence fell to about 15%. This could not be reduced further by further increasing the choline content.

5. Since the rate of body-weight gain increased as the choline content of the diet was raised to 1400 mg./kg. it is suggested that diet no. 124 may be improved from both the points of view of perosis prevention and of growth rate if the choline content is raised to 1500 mg./kg. of diet.

There are three by-products obtained from the preparation of legume seeds for human consumption which are marketed as supplemental animal foods, namely, the seed-coats (testa) which are removed from beans, peas and lentils. They are known commercially by various names, “skins,” “shells,” “husks,” “hulls” and as “offals.” They are used extensively in the East for the nutrition of cattle, where dehusked legumes enter so largely into the dietary of humans. Bean, pea and lentil husks are all used for stock feeding in Britain, and it was the frequency with which pea husks were found in commercial sheep-feeding mixtures sent for examination, and the knowledge that considerable consignments of bean shells are from time to time imported, that led to this enquiry into their nutritive value. Previous to the adoption of the Foodstuffs and Fertilisers Act, 1926, bean husks were imported into Britain in larger quantities than is at present the case, some of them being ground and added to bean meal, a practice which one has reason to believe has now ceased. Bean husks are seldom fed as such to cattle in Britain, but in France they are given to dairy cows and horses. For cows they are mixed with beet pulp, oil cakes and bran with, it is stated, good results. For horses they are mixed with oats, and an informant, a farmer from Cambrai, mixes them in equal proportions with oats for his working horses, giving to each 30 litres per day. It is claimed that the addition of the husks causes a more complete mastication of the oats and that horses do well on the mixture.

In the accompanying article attention is drawn to a source of error which arises in grading coarse and fine sand subsequent to dispersion. The method of mechanical analysis in which the error arises, and to which the writer refers, is the revised official method adopted several years ago by the Agricultural Education Association(1). The usual procedure is to wash the dispersed soil on to a No. 70 I.M.M. sieve with a jet of hot water, and to rub it gently with a rubber pestle or the finger until no more will pass through. Robinson(2) states that this rubbing is generally unnecessary. The writer has found, however, that even prolonged washing and rubbing with a rubber pestle are ineffective in removing all the fine sand. In the wet mixture the sands are held together closely by surface tension. In order to overcome this, it would seem reasonable first to dry the sieve and its contents at 105° C. and give a further light sieving. This has been done with a large variety of soils, and it has been found that an extremely high proportion of fine sand is withheld when working with certain soils. The amount of fine sand sieved out of the dried mixture increases or decreases in proportion to the amount of total sands present. This is illustrated in the accompanying graph (Fig. 1), where it is to be noticed that, in soils increasing in total sands from 50 per cent (or thereabouts) upwards, the error begins to assume serious proportions.

The effect of different cutting practices on the carbohydrate root reserves of Finnish red clover was studied. Cutting causes a rapid decrease in the insoluble sugars. The minimum is reached in about 12–15 days, independently of the time of cutting. However, the initial carbohydrate level is reached much more quickly in autumn than in June-July. The carbohydrate content of the roots in autumn is higher the later the second cut.

Cutting does not significantly affect the content of sucrose and other soluble sugars, the values for which are very low during June-August, but rise towards autumn.

1. Of various objective measurements carried out on six carcasses from each of the three Australian grades 1, 2 and Canner, the minimum depth of fat above the eye muscle at the quartering point distinguished the grades to the most significant extent, as would have been anticipated from the importance of finish in visual grading.

2. The iodine numbers of fat from the tissues of the steers examined were lower than those which would have been expected in English steers at a similar level of fatness.

The objective of the current study was to evaluate the effects of sugarcane and maize silage mixture v. maize silage in diets of Holstein cows and investigate performance under two environmental conditions. The cows were placed in freestalls, with individuals and stalls assigned to one of four treatments according to a replicated 4 × 4 Latin square design with 20-day periods divided into 11 days of adaptation (wash-out period) and 9 days of collection. Treatments were arranged in a 2 × 2 × 2 factorial design: total diets (maize silage (MS-based diet), the roughage mixture (RM-based diet, sugarcane : maize silage, 500 : 500 g/kg DM) plus concentrate); environmental conditions (with (W) and without (Wo) fan and nebulizers); and measurement times (09.40 and 14.00 h). The temperature and relative humidity was higher at 14.00 h and contributed to increased temperature-humidity index (76.6, W v. 75.9, Wo). Feed dry matter intake (DMI) was similar between diets (20.2 kg/day), but milk production and feed efficiency were lower with RM. Under W conditions, higher fat content and total solids of milk were observed with the RM-based diet, while crude protein and lactose were higher with MS. The Wo conditions increased body surface temperature (BS) in cows fed MS. The rectal temperature (RT) was higher with RM. The BS, RT and respiratory rate were higher at 14.00 h (34.9, 38.6 °C and 58.2 breaths/min) than at 09.40 h. The RM-based diet maintained DMI and milk composition, but not milk production. The use of the cooling system led to higher DMI and feed N efficiency use.

Two breeds of zebu viz. Hariana and Sahiwal were examined for the possible existence of red cell K+ polymorphism. All the animals examined appeared to be LK type. However, red cell K+ concentration varied rather widely between 7 and 50 m-equiv/1. Within the major LK type three distinct subtypes, tentatively designated as low low (LLK), medium low (MLK) and high low (HLK) were observed. The mean red cell K+ concentration in the various subtypes in the same order were 12·5, 19·5 and 38·0 m-equiv/1 respectively. LLK animals were significantly more frequent in the Sahiwal than in the Hariana breed. The possible genetic basis of the occurrence of these subtypes within the major LK type is discussed.

LLK animals had significantly higher pcv, Hb and RBC, than MLK animals. The WBC and plasma protein values were also higher, though not significantly, in the former group. In addition, animals of the LLK subtype showed consistently lower rectal temperature at comparable levels of respiratory effort under conditions of thermal stress than MLK animals.

Experiments to determine the effects of a range of applied lime and phosphate treatments on the establishment of species and the subsequent herbage production in the first and second seasons following sowing on four sites in the Falkland Islands are described and the results discussed.

Festuca rubra, Dactylis glomerata, Phleum pratense and Poa pratensis established, successfully yielding up to 4·5 t D.M./ha per year with inputs of 55 kg N, 50 kg P and 20 kg K/ha. Applied P increased the yield of herbage and produced a small, though significant, increase in P status of the soil.

The lowest level of applied lime (0·63 t/ha) increased the soil pH to 5·0 and although this did not affect the yield or botanical composition of the grass component of the sward it did affect the presence and nodulation of white clover.

The problems of establishing white clover are presented in view of the severe limitations on the use of lime and fertilizer in the Islands. The implications of grazing this improved pasture are discussed in relation to increased pasture production and improved soil fertility.

The determination of in vitro dry-matter digestibility (DMD) of grass and pasture legumes under both temperate and tropical conditions is well established (Tilley & Terry, 1963; Minson & McLeod, 1972). One application of the in vitro DMD estimation of pasture samples is, together with an estimate of faecal output, the measurement of the herbage dry-matter intake of grazing cattle. Pasture samples are usually collected with oesophageal fistulated cattle. This technique is well documented and has been reviewed by a number of authors (Langlands, 1975; Minson et al. 1976).

Rapeseed and mustard cultivars aro morphologically determinate but the growth of the raceme, which is a corymbose type, is indeterminate. On the raceme flower opening proceeds acropetally in a sequential manner with one or two flowers opening each day. Thus there is a considerable time lag between first and last flower opening within the same raceme. In these oil-seed crops, besides leaves both pod wall and stems are photosynthetically active and the share of assimilates contributed by these three organs to the growing seeds has been estimated to be 37, 32 and 31%, respectively (Brar & Thies, 1977). A rapid decline in leaf area during pod filling in rapeseed and mustard (Chauhan & Bhargava, 1984) and rape (Allen & Morgan, 1972) cultivars has been observed. The assimilate supply to the pods developing at different periods may, therefore, differ owing to a decline in the leaf source as well as increasing intornal competition between pods. In winter oil-seed rape (Brassica napus), both mutual competition for assimilates and shading resulting from excessive pod production have been reported to cause heavy seed and pod losses (Mendham, Shipway & Scott, 1981). No information is available for rapeseed and mustard cultivars on how different components of the pod, such as its weight, seed weight, number of seeds and seed oil percentage, change according to their position on the terminal raceme. This information may be useful in deciding the appropriate number of pods on a raceme for optimum yield.