In samples of wild-oat panicles collected in England and Wales in 1951 only two species, Avena fatua L. and Avena ludoviciana Dur., occurred; both were very variable in grain characters but most plants bred true. Plants of all except one type of A. fatua were upright in habit with few tillers and averaged 95% dormant grains at harvest; plants of A. ludoviciana were procumbent or prostrate at the maximum tillering stage with numerous tillers and the percentage dormant grains was lower than in A. fatua.

The taxonomy of wild oats is discussed. Chromosome counts on eleven selections showed that 2n = 42.

Types intermediate between wild and cultivated oats were compared with wild oats.

Details are given of the S/P follicle ratios of a number of British breeds of sheep. These are discussed in relation to the figures of different authors for other breeds. Figures are given for the incidence of fibre shedding and follicle abnormalities, and evidence is presented which suggests that, at any rate in British breeds, follicles are formed after birth and it is suggested that the number formed may be roughly constant in all breeds. There is an appendix describing statistical treatment of the question of follicle competition.

A study of the climate within the maize-growing areas of the West Rift area of the Kenya Highlands showed that rainfall is the major meteorological variable.

A further investigation showed that average yields of maize in subdistricts within the region are markedly affected by changes in seasonal rainfall and are apparently unaffected by large changes in acreage planted from year to year over a period of eleven years.

1. In five experiments, groups of milking cows were changed abruptly from winter-stall feeding to graze a number of different swards, and changes in the concentration of blood-serum magnesium and of other blood constituents have been studied.

2. Wide variations in the severity of hypomagnesaemia in individual cattle were found in all experimental groups, due possibly to such factors as individual variations in the intake of herbage, the requirement and body reserves of magnesium and the capacity to absorb magnesium from the gut.

3. The degree of hypomagnesaemia observed was independent of the level of milk production, but was generally less severe in Friesian than in Shorthorn and Guernsey cattle. The onset of hypomagnesaemia was delayed for a few days in cattle with a high serum-magnesium concentration at the commencement of grazing.

4. In two out of three experiments in which the effect of fertilizer treatment was studied, the incidence and severity of hypomagnesaemia was increased by the application to the sward of heavy dressings of nitrogenous fertilizer. In the third experiment, severe hypomagnesaemia occurred on a plot which had received no nitrogen fertilizer, due, it is thought, to a restricted intake of herbage magnesium, since the sward was extremely sparse. The feeding of supplements of flaked maize, crushed barley, crushed dredge corn, molassed sugar-beet pulp or a concentrate mixture balanced for milk production, to grazing cattle did not reduce the incidence of hypomagnesaemia.

5. The cutting of grass and feeding it in the stall did not prevent the development of hypomagnesaemia.

6. Blood pH and the concentrations of bloodserum calcium, sodium, potassium and blood glucose in cattle were unaffected by a change from winter feed to spring grazing, but a marked change in blood-serum non-protein and urea nitrogen and blood ammonia nitrogen, but not in any other nitrogenous constituents of the serum, was observed. The concentrations of serum non-protein and urea nitrogen and blood ammonia nitrogen were highest in groups of cattle grazing swards which had received a heavy dressing of nitrogen fertilizer and had a high nitrogen content.

7. In the two experiments in which the severity of hypomagnesaemia was increased by the application of nitrogenous fertilizer, there was a close group association between high concentrations of blood serum non-protein and urea nitrogen and blood ammonia and low concentrations of blood-serum magnesium. High levels of serum urea and blood ammonia during grazing are thought to reflect a high ammonia production in the gut, which may be responsible for the disturbance in magnesium metabolism which produces hypomagnesaemia.

1. Measurements of volume, sperm density, ergothioneine, sulphydryl groups and citric acid were made in 100 ‘tail-end samples’ (post-coital penis drips) from thirteen thoroughbred stallions. In addition, a few analyses were made of postcoital vaginal samples.

2. The ‘tail-end samples’ were found to differ substantially in their composition from that of the whole ejaculates. They lacked the characteristic gelatinous appearance of normal stallion semen, and had a much lower content of spermatozoa, ergothioneine (sulphydryl groups) and citric acid than an average stallion ejaculate.

3. As the variations in volume and composition of the ‘tail-end samples’ collected from different stallions or from the same stallion on different occasions were considerable, it is unlikely that prognostication of fertility could be usefully based on results obtained by analysis of such samples.

The grading-up system, in the Ayrshire Cattle breed, whereby the descendants of non-pedigree cows enter the registered (Herd Book) population, is studied principally from three aspects: (1) its numerical importance in the population; (2) the breeding structure of herds practising grading-up, and (3) the possible genetic effect of grading-up on milk and fat yield.

Cows at various stages of grading-up are noted in an Appendix to the Herd Book. The numerical importance of the grading-up system has varied with the rate of expansion of the breed as a whole—being greatest during the most rapid expansion—but, at all times, Appendix cows have had more registered female offspring than have pedigree cows. The volume of grading-up was regulated by the number of cows in Appendix B. Some 6% of the pedigree females registered in the last 30 years have Appendix A mothers and a further 5% or so owe their existence to grading-up during the last 30 years.

On average, the proportion of herds registering bulls is not greatly different among the herds which grade-up and those which do not. Similarly, the ratio of males to pedigree females registered was about the same in both types of herd. None-theless, there appears to be considerable selection against Appendix animals in the ancestry of bulls compared with cows, and none of the large bullbreeding studs appear to pursue a grading-up policy. A greater proportion of Ayrshire herds were grading-up in Scotland than in England.

Entry into Appendix B of the Herd Book is confined to cows reaching a qualifying yield. The daughters (A) of these B cows mated to unselected pedigree bulls were found to yield significantly more in their first lactation (36 gal. milk and 14 lb. butterfat) than contemporary pedigree Ayrshire heifers in the same Scottish milk recorded herds in 1955. Part, if not all, of this superiority is thought to be genetic.

This paper provides a general review of the effect of nitrogenous fertilizers on the yields of wheat, barley and oats. The results of 270 experiments carried out during the last decade in England and Wales have been examined.

With the exceptions noted below wheat and barley crops have produced a grain response of 3·0–3·5 cwt./acre to a standard dressing of 0·25 cwt. N/acre; this agrees well with earlier results obtained by Crowther & Yates. The widely grown winter wheat varieties, Hybrid 46, Cappelle Desprez, Bersée, Nord Desprez and Atle each produced an average response of more than 4·0 cwt./acre to the standard dressing. Of the spring barleys, Kenia, Proctor and Herta are also of greater than average responsiveness. The average response of spring oats to the standard dressing was only 1·2 cwt./acre.

The number of experiments is insufficient to allow precise conclusions to be drawn on the effect of autumn dressings, but the evidence suggests that in the drier eastern counties autumn nitrogen may give as good a response as the equivalent spring application. Small dressings of nitrogen provide equal responses whether applied early or late in spring; larger applications need to be applied early in spring (March or April) to obtain the highest yields. There is no evidence that divided dressings are more efficient than a single dressing applied in early spring.

For highly responsive varieties of winter wheat and spring barley mentioned above a dressing of 0·6–0·7 cwt. N/acre is recommended, producing a net return of approximately £10 per acre. For other varieties of winter wheat, and for spring wheat and spring barley, the recommended dressing of 0·5 cwt. N/acre produces a net return of about £5 per acre.

The response of calves to varying amounts of whole milk, as revealed by two experiments at the University of Reading farm at Sonning, is considered as a study of growth and development.

In the first experiment, which had been carried out between 1944 and 1951, seventy-five Shorthorn calves were divided into three groups (A, B and C) reared on 90, 65 and 40 gal. respectively. The treatments produced significant and prolonged differences in live weight.

A second experiment, carried out between 1952 and 1954, consisted of twenty-eight Shorthorn and twenty-eight Friesian calves in four groups (I–IV) reared on 100, 79, 57 and 35 gal. respectively. Very much less response to the treatments was found in live weight, and the effects on thirteen body measurements were even smaller, though still statistically significant. A marked difference in the response of the two breeds was apparent, the Shorthorns showing greater treatment effects in live weight and most of the body measurements.

1. Results are reported from two experiments in a series to determine the optimal amount of meal to be fed in conjunction with unrestricted whey for fattening pigs.

2. In both experiments, one carried out during the summer and the other during the winter season, the same four treatments were given. The control pigs received meal ad. lib up to a maximum of 6½ lb./ head daily. Pigs on the other three treatments received whey ad lib., and either 3 lb., or 3 lb. reduced at two different stages to 2 lb. of meal per head daily. There were ten pens of nine pigs on each treatment, involving a total of 360 pigs. Comprehensive carcass measurements were made on all pigs.

3. The data obtained showed that satisfactory results could be obtained by feeding a daily allowance of 3 lb./pig of a proprietary sow and weaner meal throughout the fattening period, in conjunction with unrestricted whey. Where the utilization of as much whey and as little meal as possible was required, it was shown that a reduction from 3 to 2 lb. meal/pig/day by the 13th week of life could be made without adverse effects, apart from an increase of approximately 12 days in the time taken to reach bacon weights.

4. Carcass grading results of all whey-fed pigs were reasonably satisfactory, but both the carcass grading and general performance of the control animals was not good. Possible reasons for this were discussed.

5. Data concerning the pattern of food consumption over 14-day periods throughout the experiments were presented. Pigs given 3 lb. of meal/day throughout, or 3 lb. reduced to 2 lb./day, consumed up to approximately 3¼–3½ or 3¾–4 gal. of whey/day respectively.

1. Two experiments involving length measurements of ninety-six bacon-pig carcasses showed that chopping out the backbones, chilling and laying the carcasses down on a table, each resulted in a decrease in average length. There was variation from carcass to carcass in the magnitude of these decreases which, in the case of the chopping out the backbone and laying down stages, was related to the fatness of the carcass, greater decreases being found in the longer, leaner carcasses than in the shorter, fatter sides.

2. Estimates of the precision of measuring showed that length from the junction of the first rib and the sternum to the symphysis pubis taken on hanging carcasses was less susceptible to errors than the same measurement taken on the lying carcass, and that both these measurements were more accurate than that from the atlas bone to the symphysis pubis taken on carcasses either hanging or lying.

A range of populations of cereals and herbage grasses, mainly of Lolium, Phieum and Triticum, have been tested in the greenhouse for response to lowtemperature vernalization. Leaf number before heading was used as the measure of reproductive development.

A close correlation was found between the climatic or agronomic origin of each population and its response to low temperature. In the cereals, response to low temperature was found in one ecological group only, namely, the winter wheats from western Europe. In Lolium the duration of the life cycle is closely related to the response to vernalization. The annual strains, such as Westernwolths or Wimmera ryegrasses, head rapidly with little or no response, while most of the perennial strains have an obligatory requirement for low temperature. In Phieum none of the populations tested exhibits any marked response to, or requirement for, low temperature, but the rapidity of heading, as measured by leaf number, varies from strain to strain and shows a high correlation with persistency. Most of the weed species tested are short-lived annuals and show little or no response to low temperature.

For each population, the local climate and farming system determine the optimum life cycle, and response to low temperature forms one important mechanism whereby such a life cycle can be attained.

The value of these methods for varietal classification and identification was assessed by comparing the behaviour of the same material in two or more seasons or under two or more kinds of equipment. The type of lighting used to provide long-day or continuous illumination, and the date of sowing, have a differential effect only in Phalaris and Phleum. In the other material, while variations in sowing date produce slight differences in the leaf number, the interaction between strain and sowing date is small, and good discrimination between population samples is possible. It is important to keep the greenhouse temperature between 50 and 70° F. to avoid natural vernalization or devernalization of material. The use of probit diagrams for comparing truncated distributions is discussed.

It is suggested that the methods can also be used to assess the genetic variation within populations. In the present results, the effect of the breeding system on the storage of variation is well shown. In self-fertilizing species, little or no variation is carried within lines, or, in the one case tested, between stocks of the same variety; it can, however, be carried between lines in a local population. In outbreeding species, each population carries considerable variation, both as genetic differences between individuals and in the heterozygous condition within individuals.

1. The rate of loss of weight has been determined for eggs from aged hens and from pullets by methods which used both an incubator at 102° F. and a desiccator at room temperature.

2. For both lots of eggs the weight loss per unit area of shell was about three times greater in the incubator than in the desiccator.

3. For the same method the eggs from the aged hens lost one and a half times as much weight per unit area as the eggs from pullets.