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.

A descriptive background is given to a group of beef farms in Jamaica on which a series of grass and animal production studies were carried out using technical and economical data derived from those farms over a 5-year period. During this time the farms co-operated in keeping standardized costaccounts and recording detailed outputs from farms and from improved and unimproved lands within those farms. Studies were made of the economics of pasture improvement and also of improvement in husbandry and breeding programmes. The possible value of the results to the small farms in the area is discussed.

Plot trials measured the effect of fertilizers and defoliation on Hyparrhenia veld.

N was the only nutrient limiting growth, and N fertilizer markedly increased the herbage yield and crude protein %. The herbage response was linear up to the highest rate used, 189 lb. N/acre, with a calculated N recovery of approximately 35%. Split fertilizer applications were only advantageous in one year out of three. The effect of N fertilizer steadily decreased at successive harvests after application, and the residual effect in a following season was transient. N fertilizers did not alter the botanical composition of the veld.

The skin is thin at birth. Seasonal variations and changes in the plane of nutrition affect the skin thickness. The differences in skin thickness between breeds of both B. taurus and B. indicus species, are highly significant. Both thin and relatively thick hides may be associated with any combination of milk and beef, early and late maturity, temperate and tropical type cattle.

1. The age of 210 days was selected for calf weight standardization. In general this is a preweaning weight under prevailing Jamaican conditions, and it represents a compromise between a very early age (90–120 days) which would reflect closely the milking ability of the dam, and the actual weaning age (approximately 260 days) when the grazing management of the herd would constitute a major unpredictable variable.

2. Either one or two weighings taken between the fourth and the ninth months of life was used to standardize calf weights to 210 days of age. In either instance for groups of calves, a mean estimate was derived which was very close to the actual mean 210-day weight, and which was suitable for data relating to groups of animals.

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.

The difficulties in the semi-arid regions of East Africa where cattle exist during the dry season on forage with a very low nitrogen content is discussed

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 data used in this study were the estimated 210-day weights of 2351 calves born on eight farms in the years 1958–61. In each year data were only used from herds which recorded at least five calves of each sex in that year. One hundred such herd years were included in the study.

2. The mean 210-day difference in weight between male and female calves was 27 lb. 1202 male calves had a mean weight of 380 lb. and 1149 female calves had a mean weight of 353 lb.

3. The response of calf weight to age of dam was different in the two sexes. The weight of the female calf was found to increase with dam age in a linear fashion, whereas the response of male calves was best described by a quadratic relationship with the maximum response at a dam age of 8 years.

1. The free amino acid content of seeds Aberystwyth S. 143 cocksfoot (Dactylis glomerata L.), S.321 perennial ryegrass (Lolium perenne L.), S. 48 and S. 352 timothy varieties (Phleum pratense L.) was studied during ripening.

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.

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.

1. An experiment was conducted in 1959 and 1960 on a rye-grass-white clover sward under a ventilated Dutch light structure to study the influence of the following treatments in all combinations. Cutting to within 1 in. or within 3 in. of ground level, cutting six times per year as for grazing or four times a year as for silage, applying water to restore the soil to field capacity (a) when the soil moisture tension at 1 ft. depth reached 10 cm. Hg, or (6) when the soil moisture tension at 1 ft. reached 50 cm, Hg, or (c) once only in the growing season. Observations were made on the effect of the treatments on the yield and seasonal distribution of herbage dry matter, the clover content, the crude-protein and crude-fibre content, and the root weights.

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.

Yields from improved (pangola) and unimproved pastures on a group of beef cattle farms have been recorded during the years 1958–62. On these farms it was shown that there was a highly significant relationship between the percentage of improved grassland and the live-weight output per acre of the whole farm. This relationship indicated that the output of unimproved land on these farms was of the order of 45 lb. per acre, and that of improved (pangola) pasture 260 lb. per acre.

1. Moderate percentages of urea are widely and successfully used in compound fertilizers but the use of large proportions may be accompanied by two disadvantages:

(a) the loss of nitrogen as ammonia from surface applications,

(b) the occurrence of toxic effects when urea and seeds are drilled together in soil. This paper shows that both these effects are consequences of the rapid hydrolysis of urea to ammonia and carbon dioxide.

2. The effect on brairding of the presence of urea and of ammonium sulphate drilled with wheat seeds, and the loss of ammonia from top-dressings of the compounds on bare soils have been studied on a range of soils. Phytotoxicity was most pronounced in those conditions in which ammonia evolution was greatest. Thus, in a sandy soil, from which about 75% of the nitrogen of a top-dressing of urea was evolved as ammonia in our conditions, more than 15 lb. nitrogen as urea per acre reduced the braird of wheat seeds; while in a clay soil, from which only 10% of a top-dressing was lost as ammonia, up to 60 lb. nitrogen as urea per acre could be added before braird was reduced. Intermediate results were obtained with three more soils and ammonia evolution and brairding were always closely parallel.

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. Heat tolerance in nine hair-coated wethers on a maintenance diet was studied during the hottest period of the year near Salisbury, Southern Rhodesia.

1. Four steers were used in thirty-five experiments each lasting 4–5 days in which the effects of variation in air velocity from 0·4 to 1·6 m.p.h. at environmental temperatures of 0°, 10° and 20°C. on heat production were studied using a respiration chamber. Measurements were made on animals with winter coats and in the same animals after shearing.

2. Standing time was increased by exposure to cold and slightly reduced by exposure to wind. The wind was so small that it had no effect on the measured coat depth. Piloerection increased winter coat depth by 30%. Heat production was increased by 17–20 kcal./hr. on standing.

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.