Two groups of steer carcasses, eight Holsteins and eight Herefords, were compared in carcass traits. Although the quality of the meat (colour, texture, firmness, marbling and maturity) was comparable for both groups, the Holstein carcasses were heavier, older in chronological age and showed less thickness, plumpness and general compactness.

1. Three fistulated and four unfistulated crossbred sheep were each fed once daily with diets of lucerne or wheat.

2. A pre-feeding sample of the rumen liquid was examined for its content of protozoa, of various chemical components and for its enzymic activity on glucose and on soluble starch. Several samples were taken from each sheep at intervals over periods of up to 8 weeks, during which time the sheep were maintained solely on the single diet.

3. Considerable variation occurred, both between sheep and between samples from the same sheep, in the concentrations of ciliate protozoa and of lactic acid, especially on the wheat diet.

4. Analyses for nitrogen, pH, dissolved C02, volatile fatty acids and for the molar proportions of acetic and propionic acid showed differences due to diet.

1. Three fistulated cross-bred sheep were fed diets which consisted solely of lucerne, cereals or potatoes. Potatoes were fed both in the raw and in the cooked form.

2. A pre-feeding sample of the rumen liquid was examined for its content of protozoa and various chemical components and for its enzymic activity on glucose and on soluble starch.

1. The transferrin types of 225 Jersey cows in thirteen herds, and 433 Australian Illawarra Shorthorn cows in twenty-four herds in Queensland were determined. The effect of transferrin type on lactation length, milk yield, butterfat yield and butterfat percentage was assessed by a leastsquares multiple linear regression analysis.

2. The results for the two breeds did not differ significantly. Combining the data from both breeds, it was found that on average D/D cows had lactations 13·9 days longer than A/A cows (P < 0·01), and yielded 449·7 lb. more mills (P < 0·01). The results for A/D cows were intermediate.

Coastal Bermuda grass tolerated the highest rate (16·7 p.p.m. N) of dicyandiamide with no decrease in growth although mild toxicity symptoms were observed. The data in Tables 1 and 2 show that with a constant rate of sodium nitrate and increasing rates of dicyandiamide the yields of maize, oats and wheat gradually decreased. The effect must be direct toxicity of dicyandiamide as plants receiving ammonium sulphate were not injured to any greater extent than those receiving sodium nitrate. The author's observations are in agreement with the Coastal Bermuda grass tolerated high rates of dicyandiamide; oats, wheat, maize and cotton were moderately injured and tomatoes were severely injured by the higher rate (16·7 p.p.m. N) of dicyandiamide. With a constant rate of sodium nitrate and increasing rates of dicyandiamide the yields of maize, oats and wheat gradually decreased indicating that the toxicity of dicyandiamide was a direct injury. Visible toxicity symptoms were observed on plants receiving 6·7 p.p.m. N or more of dicyandiamide in the soil. The highest rate (16·7 p.p.m. N) caused progressive withering of leaves from the tip and subsequently depressed the growth of cotton, oats and tomatoes. However, a low content of dicyandiamide (not exceeding 15 lb./A) in nitrogen fertilizers may benefit plant growth.

1. An experiment conducted on a light gravelly soil at Cambridge which compared the effects of different sequences of cropping, some of which contained leys of various types and duration, different levels of nitrogenous manuring, and the application of farm-yard manure on the yield of potatoes, is described and the results discussed.

2. Under the circumstances of the experiment, in which phosphate and potash were maintained at a high level on all plots, sequence of cropping had little effect on the yield of potatoes when 4 cwt./acre of ‘Nitro-Chalk’ was applied to the potatoes, but in the absence of applied nitrogen leys containing lucerne led to higher yields than other sequences.

1. One long-term experiment comparing the effects of leys and arable cropping on the yield of arable crops and three experiments on the effect of management of lucerne/grass leys on the following arable crops, all conducted on heavy clay land, are described and the results discussed.

2. In the first two years after breaking a ley yields of wheat were higher than on plots which had had all-arable cropping and it is suggested that this effect could be due to a combination of disease and weed control and the nitrogen status of the soil.

1. Three experiments designed to investigate the effects of consolidation and aeration of soil beneath potato seed tubers before planting, and inter-row grubbing after planting, on the growth and yield of potatoes are described and the results discussed.

2. Consolidation of furrows beneath seed tubers by tractor wheels at planting had no effect on total weight of ware-size tubers produced but increased the weight of mis-shapen waresize tubers. It is argued that this effect was related to soil moisture content and tilth at planting time.

Pre-mating, pregnancy and lactation periods correspond approximately with summer, winter and spring and any effects either of physiological status or nutritional conditions are confounded with the natural rhythm of wool growth. Within this framework, barren ewes produced slightly more wool than in-lamb ewes in winter and considerably more during the period of lactation. Improved nutrition during winter produced no increase in wool production, although it had a marked effect on live-weight maintenance. During lactation, improved nutrition resulted in an increase in wool production. The implications of the nutritional and seasonal rhythm of wool productions are discussed in relation to the adaptation of the breed to its environment.

1. In grass seed crops accurate assessment of the optimum harvest date is made difficult by the lack of knowledge of seed ripeness. In order to define ripeness in physiological terms studies have been initiated the first of which is described in this paper.

2. Samples of Aberystwyth S. 321 perennial ryegrass (Lolium perenne L.), S. 143 cocksfoot (Dactylis glomerata L.), S. 48 and S. 352 timothy varieties (Phleum pratense L.) were taken at 3-day intervals from inflorescence emergence to seed harvest. These were analysed for total 80 % ethanol soluble carbohydrates (TSC) reducing sugars, sucrose and starch, whilst duplicate samples were air-dried for determination of thousand seed weight and percentage germination.

1. Laboratory experiments compared alternative ways of placing urea for wheat. Urea greatly increased the pH in the seed-row; placed in contact with seeds, it killed many plants, but did not when placed 1 in. to the side of the seed.

2. A combine-drill was modified so that, by simple adjustments, fertilizers could be placed in contact with the seed, or at 1 in. to the side of the seed, or broadcast over the seed-bed.

3. Fifteen experiments with spring barley and one with spring wheat, made from 1960–62, compared yields from urea with yields from ammonium sulphate; calcium nitrate and sodium nitrate were tested in seven and in six experiments, respectively.

This study compared ¾ Hereford–¼ Brahman calves with Hereford calves under Imperial Valley conditions. The calves produced in four successive crops were all paternal half sibs.

The cross-bred calves outgained the Hereford calves in the summer both on pasture and in the feedlot; the reverse was true for feedlot gains during the fall and winter, the period of non-stressful weather in the Imperial Valley for British type cattle. Possible causes for the breed by season interaction are discussed.

1. Fourteen muscles from a normal 46-week-old Friesian heifer and from its 40-week-old half-sister, which showed the pronounced muscle hypertrophy of ‘doppelender’ cattle, were analysed for moisture, hydroxyproline, sodium, potassium, total nitrogen, and intramuscular fat: the iodine number of the latter was determined. In four of the muscles sarcoplasmic, myofibrillar and stroma nitrogens were also estimated.

2. Hypertrophy was associated with a mean increase in the percentage of total nitrogen, with markedly lower percentages of hydroxyproline and of intramuscular fat, and with a decreased K/Na ratio.

The kinetics of the isotopic exchange of phosphate ions in soils with and without phosphate added in the laboratory were examined in relation to the amount and origin of the CaCO3 they contained. The isotopic exchange index, ‘Pr/Pe’, and the recovery of added phosphate were inversely proportional to carbonate content in soils containing carbonates of similar geological origin; soils from the Lower Lias showed the biggest change in Pr/Pe with carbonate content.

In soils from the Cretaceous Chalk, the first-order rate of isotopic exchange of the ‘slow’ phosphate fraction was constant. It increased to a larger but constant value in the soils incubated for 6 months after adding phosphate in the laboratory. This rate constant is therefore specific to the calcium phosphates in a group of soils derived from the same calcareous parent material and with similar phosphate manuring.

1. Over 3 years, different levels of first winter nutrition were imposed on groups of North and South Country Cheviot ewe hoggs (lambs). In 1956–57, three levels, high, mid and low, were fed indoors. In 1957-58, only two levels, high and mid, were fed indoors, with the low level being represented by hill wintering. In 1958–59, two levels were represented by away wintering and hill wintering.

2. Low-plane feeding was designed to simulate average hill wintering, creating a 10% loss in live weight. Mid-plane feeding was designed to maintain live weight at approximately the same level throughout the winter. High-plane feeding was designed to produce a live-weight gain of 15–20% in 1956–57 and the maximum gain possible in 1957–58.

1. Over 3 years, different levels of first winter nutrition created the following live-weight differences between groups of North and South Country Cheviot ewe hoggs at 12 months of age. High plane (H.P.) and mid-plane (M.P.) fed groups born 1956 were 34–35% and 11–13% heavier, respectively, than low plane (L.P.) fed groups, H.P. and M.P. fed groups born 1957 were 47–57% and 18–24% heavier, respectively, than hill-wintered groups. Away wintered groups born 1958 were 9–12% heavier than hill-wintered groups. All group differences were highly significant.

2. From 12 months onwards all groups were run together on the same hill and received similar management. Live weight and live measurement response of the total treatment groups and of the heavy and light hoggs within the groups prior to treatment were studied over the summer after treatment from 12 to 18 months.