The efficiency of the utilization of the energy of casein in adult fowls at different feeding levels both for maintenance and for lipogenesis, was studied. The casein was utilized for maintenance with an efficiency of 66·6 ± 1·3% of the gross energy and of 83·7 ± 1·4% of the metabolizable energy. For lipogenesis efficiencies were 51·6 ± 2·15%, and 61·3 ± 2·6% respectively.

Intravenous glucose tolerance tests were performed on thirty-four sows when they were either non-pregnant or in very early pregnancy. It was found that there was a relation between each sow's glucose tolerance and the mean of the mean birth weight of all her litters. The relation was expressed by the equation Y = 0.013T + 0.81 (R.S.D. ± 0–124 kg) where Y = birth weight and T = glucose tolerance as minutes for blood glucose to return to fasting concentration. The correlation coefficient was +0.58. The addition of further variables to the equation (sow's live weight at test, sow's parity at test and the number of pigs per litter) did not give any useful improvement of the estimate of birth weight.

A digestibility and metabolism experiment was carried out to study the effect of two levels of feeding Rhodes grass-concentrate mixed diets when the grass had been preserved as hay or as frozen grass. Twenty Awassi lambs were used.

The method of preserving the Rhodes grass did not affect the digestibility of dry matter, crude protein or nitrogen-free extract. However, the digestibility of energy and crude fibre was lower with the hay treatments.

A consistent trend towards higher digestibility of the diets' constituents was observed with the high level of feeding.

Acetic acid concentration in the rumen was lower with the hay than with frozen grass. Feeding the high level resulted in higher concentrations of volatile fatty acids in the rumen.

A highly significant effect of the level of feeding on the C2/C3 ratio was observed; the high level of feeding resulted in a lower C2/C3 ratio

Two experiments were carried out in Scotland 1984 to study the efficiency of energy utilization by Suffolk × Blackface lambs. In the first experiment, a digestibility trial, the lambs were fed three diets: roughage (R) consisting of chopped dried grass; concentrate (C) containing 700 g whole barley, 225 g ground barley and 75 g fishmeal/kg dry matter (DM); and a mixed diet (M) containing 500 g of roughage and 500 g of concentrate/kg DM. The DM and organic matter digestibility coefficients of diet M were lower than the ‘expected’ values calculated by summation of the separately determined digestibility coefficients of the component feeds. Similarly, the metabolizable energy (ME) value was 4·0% lower than expected.

In the second experiment, 40 lambs of c. 20 kg live weight (LW) were offered 50 kg roughage DM (ME 9·74 MJ/kg DM) and 50 kg concentrate DM (ME 12·21 MJ/kg DM) either as a mixture (treatment M) or sequentially (treatment S). Lambs on treatment S took 33 days longer to consume their allocation of food than those on treatment M, but achieved a similar final empty body weight and empty body composition. This contrasts with results predicted by a feeding standards model for lambs of a similar LW offered diets of the same ME content. The longer feeding period, and hence greater overall maintenance requirement, of lambs on treatment S was partly offset by associated effects causing a reduction in the total ME available to lambs on treatment M, and partly to improved efficiency of energy utilization for gain and/or a lower daily maintenance requirement of lambs on treatment S. Allowing for associated effects and the adoption of a variable maintenance requirement in current feeding standards would result in a more accurate prediction of animal performance.

It has been reported recently (Stott, 1974) that in cattle, reproductive efficiency is increased by keeping the animals under cool climatic conditions. However, in buffaloes very limited information is available. Roy, Sengupta & Misra (1962) have reported that all buffaloes exhibited oestrus and were inseminated in a group protected from direct sun radiation whereas in a non-protected group only one showed oestrus. There is no systematic information available on the effect of wallowing and showers on the oestrual behaviour of buffaloes. Therefore, the present investigation was undertaken to study the effect of cooling on oestrual behaviour in buffaloes.

Experiments in 1976 and 1977, in south-east Scotland, with sunflower (cv. Fransol) examined the effects of bitumen mulch applied after sowing, date and depth of sowing on emergence, flowering and yield. Bitumen mulch increased soil temperatures in April and May by 1–4·5 °C resulting in earlier emergence (6–7 days), more complete emergence under adverse conditions of early and deep sowing, and earlier flowering (2–5 days). Delaying sowing from 7 April to 5 May reduced emergence time and time from sowing to first anthesis. Larger seedlings, having an increased leaf area, resulted from bitumen mulching and early sowing.

In the laboratory, increasing temperatures from 5 to 20 °C reduced the average germination time by 0·75 days for each increase of 5 °C. Germination percentage was not affected by temperature over this range.

Average seed yields and oil content were markedly different in 1976 and 1977; 2·22 t/ha and 44·7% for 1976 and 0·95 t/ha and 36·9% for 1977. Bitumen mulch and sowing depth had no effect on seed yield or oil content but delaying sowing until 5 May reduced both. Lower seed yields in 1977 resulted from fewer and smaller seeds. Infection of the seed heads with grey mould (Botrytis cinerea) after flowering was high in both years.

Many authors, for example, Settegast, Pusch, Kašpárek, Kraemer and Rostafinski, have attempted to draw conclusions concerning age, quality and breed of cattle from the type of hair produced. Exact investigations of the length and other features of the hair are, however, rare in the literature. Bilek has recently made some investigations of this kind under the direction of Professor Kašpárek, and has estimated the relation between the medulla and the fibrous layer, and has shown that the cross section of the hair is sometimes circular and at other times elliptical in shape.

The distribution of body water in the different body compartments of four highpotassium (HK) and four low-potassium (LK) type sheep of the Marwari breed of the Rajasthan desert was determined after imposing the following watering treatments, viz. watering ad lib., ¼, ½ and ¾ restrictions (each of five days ‘duration with a sevenday normal drinking regime between each treatment) and water deprivation (of three days’ duration). There was no difference in the voluntary water intake of the HK and LK animals. The HK animals normally have a higher blood and plasma volume status than the LK. In both types of animals, the total body water, total blood and plasma volumes and the extracellular, intracellular and interstitial fluid volumes started decreasing as water intake was reduced below 25% of the daily requirement. In both the phonotypes 75% reduction was similar in its effect to complete deprivation. The physiological status of the HK Marwari animals appears to be somewhat superior to that of the LK although both types seem to be equally adapted to the conditions of the habitat.

1. The frequency of excretion of droppings by hens varied considerably over the day and much of this variation appeared to be related to the disturbance of the birds by attendants.

2. Data relating to dry-matter excretions by five birds for 17 days were used to study the influence of zero hour and length of the time unit on variations in this dry matter.

3. It was found that, in this experiment, 14.00 hr. appeared to be the best zero hour, but it was suggested that, considering the heavy excretion of material around 06.00 hr. when the birds are first disturbed in the morning, 07.00 hr. might be the ideal time. Data from an earlier experiment supported this.

4. There was a decrease in variation up to a unit of time equal to 3 days and times not multiples of days gave greater variations. There were, however, considerable differences between birds.

Chlorophyll contents per unit leaf area and unit dry weight, chlorophyll a:b ratio, visual colour rating, specific leaf area, and leaf fresh weight: dry weight ratios were estimated for 12 couch (bermudagrass) varieties (Cynodon spp. L.) in winter (July) and spring (October). Net photosynthetic and dark respiration rates were estimated in winter only.

The chlorophyll contents per unit leaf area were higher in all varieties in spring than in winter, but per unit weight were more variable. The varieties differed substantially in the net photosynthetic and dark respiration rates. The specific leaf areas were greater in winter than in spring in five varieties: in others it changed little. The fresh: dry weight ratios of the leaves were almost constant between varieties in the spring but varied greatly during the winter. Visual colour ratings were well correlated with chlorophyll contents per unit area but not with weight. The net photosynthetic rate was closely correlated with chlorophyll content (per unit area) but not so closely with colour rating.

The investigation bears out the conclusion of the Rothamsted experiments that leaching out may occur any time throughout the winter up to March, or rarely April.

The loss of nitrates is directly limited by the amount of drainage and so is indirectly determined by the rainfall, and by temperature—as it affects the rate of evaporation.

All three nitrogenous fertilisers are shown to lose well over 50 per cent, of a normal dressing by leaching out during the winter, but the loss is greatest in the case of sulphate of ammonia, least in the case of rape dust, calcium cyanamide being intermediate.

The writers wish to express their indebtedness to Miss N. Sugg who carried out the experimental work in the first winter.

1. Activity of Lumbricus terrestris, Allolobophora caliginosa and A. chlorotica was unaffected by 15 mg. hexoestrol in solution in 500 g. soil.

2. Activity and reproduction of A. caliginosa was unaffected by 10 mg. hexoestrol in 500 g. soil, but 100 mg. and over affected activity and stopped reproduction.

3. Egg capsules of A. caliginosa and A. chlorotica developed normally in a saturated aqueous solution of hexoestrol.

4. No effect on the soil fauna of grass plots due to grazing with implanted bullocks was observed.

Hofuf-Alhassa is one of the important agricultural areas of the Kingdom of Saudi Arabia. The water available for irrigation purposes is limited in quantity and saline in nature.

To maximize the use of available water sources, a technique is described to mix irrigation water with drainage water, taking into consideration the salt balance effect in the soil under the Alhassa conditions.

The effects of crop density and fertilizer application on three varieties of marrowstem kale were investigated. The yield of stem, yield of leaf, components of leaf yield and plant height were studied separately. Varietal differences and effects of density and fertilizer application were significant for all characters, except for the effect of crop density on leaf and stem yield per ha.

Significant variety x treatment interactions occurred for a number of the characters measured. The possible importance of these is discussed.

Measurements have been made of the electrical conductivity of aqueous suspensions of stored soil samples taken at intervals of several years from four of the Rothamsted classical plots bearing the same crop every year. The results show that under continuous cropping:

1. The initial conductivity (and therefore the soluble salt content) of an unmanured soil decreases steadily to a minimum value, which then remains fairly constant over a long period of years. There is reason to believe that, under the same conditions, the normal initial conductivity of a continuously manured plot (excluding the temporary increased measurements due to application of manure) decreases similarly to a fairly constant minimum value, which is slightly greater than that of an adjacent unmanured soil depending on the kind and probably on the quantity of manure applied.

2. The 7 days’ increase of both unmanured and manured soil decreases progressively. In the case of an unmanured soil for which earlier samples were available, the 7 days’ increase is found to decrease comparatively rapidly during the first few years of continuous cropping.

Prof. T. B. Wood in the November issue of the Journal of the Ministry of Agriculture discussing the known methods of estimating the nutritive values of foodstuffs says, “there is a method which is within the scope of any experimenter and is capable of yielding accurate results of great practical value,” and he goes on to give examples, in the estimating of the nutritive value of swedes, kale, etc., using the results of an experiment which entailed the use of 40 to 120 animals. From these experiments he gets results showing a very satisfactory agreement between experiment and calculation, notwithstanding that there must be a slight experimental error in the calculation of food consumed.

Tetraploid lines were produced from colchicine treatments of European multigerm diploid material, and seeded in polycross plots. The same lines were crossed with European multigerm diploids to give anisoploid varieties, and also used as pollinators of American male-sterile diploids to yield monogerm and multigerm triploid varieties. Bigerm triploids were obtained from male-sterile hybrids heterozygous for the monogerm character, using European multigerm O-types in the grandparental generation. Double-cross monogerm triploids were obtained by crossing male-sterile diploids with non-equivalent O-types to provide male-sterile hybrids, and pollinating these with outbred tetraploids.

Results from 35 root-yield trials showed that the sugar yields of the anisoploids and triploids were similar to those of contemporary commercial varieties, but that outbred tetraploids were slightly, and inbred tetraploids considerably, less productive. Changes induced in characters other than root weight by chromosome-doubling of diploid material were sometimes important, but not consistent in magnitude or direction. It is suggested that these changes result from selection and random drift rather than the ploidy change.

A seed-yield trial demonstrated advantages of using hybrid seed-parents for triploid seed production. Problems of seed quality are discussed with particular reference to triploid varieties.

It is concluded that the main importance of multigerm anisoploid varieties was in their combination of good sugar yield with near-monogerm fruit clusters at a time when commercial monogerm varieties were deficient in yield; the chief value of triploidy lay in its application to the short-term improvement of genetic monogerm varieties. The development of monogerm anisoploids is considered unlikely; but some advantages of deriving monogerm triploid varieties from tetraploid seed-parents are indicated, and it is suggested that these may become increasingly important in the future.

The cost of developing and maintaining pangola grass pastures has been examined under a range of conditions. The direct cost of improving pastures to the stage where they were established as 5–10 acre, fenced, watered units of pangola grass was about £30 per acre. Under favourable conditions this cost could be reduced to £20, but with difficult land or poor techniques the cost could rise to £40 or more per acre. In addition to the direct cost of establishment there was an indirect cost due to land being out of use or stock numbers having to be reduced. This indirect cost appeared to be highest on lands where planting costs were least. It was suggested that there might be an inverse relationship between direct and indirect costs which tended to narrow the total range of establishment costs.

The present method of estimating preliminary results in artificial insemination practice bears a definite relation to calving percentages, and, with few exceptions, may be generally adopted as a true measure of fertility.

Single factors, such as an individual bull with a low conception rate, a new and less efficient inseminator, or variations in the results obtained at the Sub-Centres, etc., do not noticeably affect the average monthly conception rate in a large A.I. Centre. The most important influencing factors have been found to be the choice of diluent, and in some cases the elimination of the use of stored semen.

No significant variation in fertility occurs with the season of the year, the age of the bull or the area of operation; but, for a bull to work satisfactorily at a centre and at the same time achieve good results, it is necessary that he should be treated as an individual and his psychology closely studied.

In view of results obtained, one is able to conclude that methods of evaluation at present in use (estimating initial motility, density, percentage of abnormals and a test of viability by storage of diluted and undiluted samples) are up to a point satisfactory.

A dilutor or buffer may influence the conception rate considerably, and it is felt that the diluent in use at present has its own fertility level.

With the Centre's team of forty-eight bulls it is obvious that there must be some variation in fertility levels between individuals; but it is seen that, whereas bulls in natural service fall obviously into categories of ‘high fertility’ or ‘low fertility’, this division tends to disappear in A.I. with the application of the various techniques.

As a nitrogen fertilizer for vegetable production in Britain ammonia has been used mainly for bruasels sprouts (Page, Tatham & Wood, 1974; Page, 1975a; Page, Wood & Case, 1976), and leeks (Page & Williams, 1977). These crops with long growing seasons allow considerable latitude in time of application of the ammonia. Summer and autumn maturing cauliflowers have not only a short growing season, but also have a physiological control of curd formation which appears to be insensitive to nitrogen supply (Salter, 1969; Salter & Fradgley, 1969). They are also usually transplanted into the field, and the root system is therefore restricted for at least part of the growing season. It is therefore desirable to know if the roots would reach the injected nitrogen in time, as, until the ammonia becomes nitrified, nitrogen movement in the soil is small (Page, 19756). Thus, time of application of the ammonia was considered likely to be important.