Milk records and records of farm and herd management collected over a 2-year period have been used to study the effects of seasonal changes in climate, feeding and management in each of four Dairy Shorthorn herds.

Differences in climatic conditions and management between the four farms appeared to be reflected in mean lactation yields, herd D having a slightly higher, and herd C a considerably lower average than the other two herds.

In each herd, mean yields in each week were corrected for the effects of potential productivity and mean stage of lactation of the cows to give a weekly value designated the yield index. Variations in this quantity were used as a measure of the effects of seasonal changes in climate, feeding and management upon milk yields.

A comparison of methods of measuring the structural condition of cultivated surface soil was made for two important East African soil types.

The soil samples were drawn from two field experiments: (i) a tillage trial in coffee on a porous red lateritic clay soil of recent volcanic origin; (ii) a rotation trial for cotton, on a red sandy lateritic loam of granitic origin.

Of the measurements on soil cores, total porespace and field capacity (⅓ atmosphere) showed little change, while percolation rates, free-draining pore-space and a new rainfall acceptance test all reflected the observed field behaviour of the soils, and showed fairly close and highly significant correlation. Field sieving of dry clods gave highly significant differences in the lateritic clay, the stronger clods indicating the poorer soil condition. Drysieving for ½ mm. crumb was ineffective, as was wet-sieving after wetting under vacuum. Wetting by immersion gave some differences between treatments, but higher variability and no significant correlation with free-draining pore-space. Wetting by rainfall impact on dry crumbs gave the best wet-sieving tests on the clay soil. Different sieving techniques gave inconsistent results on the sandy soil. Crumb structure measurements are not efficient indications of structural conditions on these soil types, which are of wide occurrence in tropical countries.

The petroleum-ether extractable oil content of native oats (dry-weight basis) ranges 3·0–8·5%, and is chiefly dependent upon variety and kernel content (which is itself a varietal characteristic). That of the kernel, which comprises 64–81% of the grain by weight, is 4–11% with a spread of about 2·5% within the variety. The kernel contains in addition about 2·5% of more complex insoluble fatty material which is released on acid hydrolysis. The husk, on the other hand, contains only a few tenths of one per cent of petroleum-ether soluble oil together with about 1% of more complex material that can be released by acid hydrolysis.

Certain environments favour higher levels of oil content within all varieties whereas others favour lower levels; Scottish samples tend to be slightly higher in oil content than English samples of the same variety.

The free fatty acid content of the oil in the kernel ranges 3–10% for sound, viable grain; the value for any sample is more dependent on environment during cultivation, harvest and storage than on the variety. After the grain is milled or pulverized the free fatty acid content rises to much higher levels within a few days.

The nitrogen content of oats depends chiefly on the nitrogen content (1·4–3·9%) of the kernel and the kernel content (64–81%) of the oats, the husk containing only 3–10% of the total nitrogen in the grain.

Varietal differences are significant but small in comparison with the overall variability: they reach 0·3% nitrogen in a few cases. Variation between random samples is largely due to soil differences, with region and harvest year responsible for smaller effects. The predominant factor governing nitrogen level in oats of all varieties probably is, as for wheat, the level of available nitrogen in the soil in late spring and early summer, just prior to heading and during development of the grain.

Within the variety there is a pronounced inverse correlation between nitrogen and oil content which is independent of grain size: the variability of the oil content within the variety is, however, smaller than the corresponding variability of the nitrogen content. At some localities environmental factors of soil and season, particularly the former, inhibit the filling out of the grains which then ripen prematurely to give small oats with lean kernels of high nitrogen content, and favour within the variety a negative correlation between grain size and nitrogen which otherwise might not be apparent.

1. Two 4-month-old Ayrshire calves were subjected in a climatic room for periods of 2½–4½ hr. to an atmosphere having a temperature of 35° C. and an absolute humidity of 34 mg./l.

2. This treatment resulted in an increase in respiration rate, a decrease in carbon dioxide tension and carbon dioxide combining capacity of the venous plasma, an increase in the lactic acid concentration of the venous blood and an increase in the pH of the urine. The pH of the venous plasma showed only a slight tendency to increase.

3. It is concluded that thermal panting under the conditions described caused a carbon dioxide deficit which was just compensated for by the excretion of alkali by the kidneys, and that this compensation was not substantially influenced by the production of lactic acid resulting from an increased activity of the respiratory muscles.

(a) Measurements made on sides of bacon exhibited since the war at the National Pig Breeders' Association carcass shows at Stirling and Peterborough and on various commercial sides have been analysed to investigate differences between the shows, the years and the sexes.

(b) In the Large White exhibits the sides from gilts were on average longer, thicker in the belly, thinner in back fat and with better developed eye muscles than the sides from hogs.

(c) The area of the eye muscle of the carcasses entered in these shows between 1948 and 1952 shows an unexplained decrease over this period. The width of the eye muscle is the only character showing a definite show difference, being larger at Stirling than at Peterborough.

1. The respiration rates of three 4-month old Ayrshire bull calves were measured in individual 6 hr. daily exposures to 15, 20, 25, 30, 35 and 40° C. dry bulb temperatures at 17 mg./l. absolute humidity and at 7 mg./l. saturation deficit at temperatures of 30, 35 and 40° C. in a planned sequence of environmental temperature. The schedule of experiments on each animal lasted 45 days consisting of five replications of these nine environmental conditions. Throughout the experimental programme the respiration rates of these three animals and of three control animals were measured in a holding room just before the experimental animal of each pair was transferred to the hot room.

2. The frequency of respiration of all the calves increased with increasing environmental temperature and humidity.

1. The heart rates of 4-month-old Ayrshire bull calves were measured in individual 6 hr. daily exposures to 15, 20, 25, 30, 35 and 40° C. dry bulb temperatures at 17 mg./l. absolute humidity and at 7 mg./l. saturation deficit at temperatures 30–40° C. The schedule of experiments on each animal lasted 45 days and consisted of five replications of these nine environmental conditions. Throughout the experimental schedule the heart rates of three paired control animals were measured in a temperature-controlled holding room.

2. The heart rates of all experimental animals increased with increasing environmental temperatures above 20° C. and with increasing humidity above 30° C.

1. Nitrogen transformations during the decomposition of straw composted with ammonium carbonate have been studied by following the changes in (a) the amounts of inorganic and organic nitrogen; (b) the amounts of ammonia-, volatile base-, α-amino- and amino sugar-N liberated by acid hydrolysis of the organic nitrogen complexes; and (c) the amino acid composition of acid hydrolysates of the composts.

2. Synthesis of organic nitrogen during the biological decomposition of straw composted with ammonium carbonate is not accompanied by any gross change in the distribution of the forms of organic nitrogen. A large fraction of the organic nitrogen synthesized is in the form of protein; a smaller fraction is in the form of amino sugar.

Migration of pedigree Ayrshire cattle in the British Isles is estimated for 1927 and 1946 from samples of herd-book registrations. Most migration is from Scotland, particularly Ayrshire, to England, but considerable numbers were also transferred between regions within Scotland or England. A larger proportion of bulls than of cows was moved in this way. Only a small proportion of animals had two parents bred in the same herd as themselves. If the males and females registered from England in 1946 were the sole parents of the next generation, the latter would still have more than half Scottish blood.

The amount of movement of Ayrshire cattle shown by these data virtually precludes genetic differences between regions, but not perhaps between herds. Other implications of movement are discussed.