A mixed sward of grasses and clovers, previously established with adequate Ca, N, P and K on deep acid peat, was used for a factorial experiment to determine the amounts of nutrients required to produce herbage for conservation. The treatments consisted of all combinations of 0, 117and 234 kg N, 0, 29 and 58 kg P and 0, 156 and 312 kg K/ha, and their effects on the botanical composition of the sward, the yield and mineral composition of the herbage, and the nutrient status of the peat were measured over a period of five years. Three cuts were taken annually, one third of the N dressings being applied for each cut.

Tall fescue became the dominant grass species while cocksfoot persisted much better than either ryegrass or timothy. The proportion of clover in the sward was reduced to practically zero by applying N, but without N it was maintained at about 20% by applying K.

Yields of dry matter were greatly increased both by N and by K and there was a marked positive interaction between these two nutrients. Due to the marked suppression of clover by applied N there was no response to the first increment of N in 1959, but with this exception, 1 kg N/ha with adequate P and K produced between 15 and 30 kg dry matter/ha. The effect of K increased from 1958 to 1962, the first increment consistently producing most of the response. Applying P had little effect on yield until the fifth year when a significant response was obtained.

The mineral composition of the herbage varied during the season; the percentages of N, Ca, Na and Mg were generally higher in autumn than in early summer whereas the percentage of K showed the opposite effect.

The N, P and K treatments had large effects on the percentages of N, P, K, Na, Ca and Mg in the herbage and on the amounts removed in the crop. Without applied N, but with adequate P and K, percentage of N varied according to the amount of clover in the sward. With applied N there was less variation and the average percentage of N was about 1·7 with 39 kg N and 2·0 with 78 kg N/ha/cut. Percentage of P ranged from 0·14 to 0·54 and percentage of K from 0·5 to 3·5. Apparent recoveries up to 74, 65 and 96 % were obtained from the N, P and K treatments, respectively.

For continuous production by cutting and removing the herbage, a mixed sward containing clovers appears to require, without applied N, about 120 kg K/ha/year. With applied N, an additional 0·3 to 0·5 kg K/kg N appears to be needed. The amount of P required will depend mainly on the concentration desired in the herbage and on the rate of N used. To produce herbage with 0·3 % P in the dry matter about 15 kg P/ha/year, plus approximately 0·1 kg P/kg N applied seems to be needed; for 0·4 %P the corresponding quantities are about 40 kg P/ha plus 0·3 kg P/kg N applied.

Two sets of correlations among blood mineral concentrations were calculated (1) those attributable to the effects of various factors (breed, age, lambing performance, etc.) and (2) those remaining (residual) when the effects of such factors had been removed as sources of variation in mineral concentration (the equivalent of correlations within subclasses).

Correlations arising from breed differences in mineral concentrations were highest for Ca.P (– 0·81), Ca.Cu (0·83) and P.Cu (–0·95). Correlations consequent on changes with the age of the sheep were most marked for Ca.Mg (0·97, P < 0·01) and Cu.K (–0·92, P < 0·05) and approximately 0·8 (P < 0·1) for Ca.K, P.Mg, P.K and K.C1.

Residual correlations were all below 0–2 (although seven of the twenty-one were statistically significant, P < 0·05) suggesting that within subclasses most of the variation in the concentration of anyjone mineral was independent of that in the other minerals. Simple and partial correlations were very similar in magnitude suggesting that the associations found between pairs of minerals were not attributable to joint co-variance with any of the other five minerals.

As the sheep grew older, changes in the concentrations of Ca, P and Mg were significantly correlated with the increases in live weight. Within subclasses, differences among the sheep in live weight were significantly (P < 0·05) and positively correlated with differences in the concentrations of Ca (r, 0·11), Mg (0·13) and Cu (0·11).

Para-rubber (Hevea brasiliensis Muell-Arg.) is a major plantation crop in South-East Asia. In addition to its economically important latex, the para-rubber tree produces seeds that serve as a source of industrial oil. Rubber seed meal (RSM), a by-product of the oil extraction, contains moderately high amounts of crude protein and is available at lower prices than most traditional vegetable protein supplements in the region. The estimated availability of RSM in South-East Asian countries is about 1·2 million tonnes.

Calcium metabolism in dairy cows has been studied at three periods, namely 2 weeks before and 2 weeks after parturition, and also at peak lactation. Of the four parameters studied—percentage absorption from the diet, endogenous excretion, exchangeable pool size and bone accretion rate—only the last showed significant changes, falling at parturition and rising to pre-calving levels subsequently. There was no increase in the percentage absorption of calcium from the diet after calving but total calcium absorption rose because of increased dietary intake.

The main conclusions that can be drawn from these field experiments to compare the effect of different methods of preparing the seed bed on the crop's growth are:

(1) Crops germinate faster on the looser seed bed prepared by a Rototiller than on the more compact ones prepared by a plough or a grubber. The total number of plants that germinate is, however, the same for all treatments unless the land is too foul with weeds, when higher germination is obtained on the cleaner plots.

(2) Cereals tend to ripen a little sooner on land that has been ploughed than on land that has been either rototilled or grubbed, but in most years this effect if present is very small.

(3) The shape and the weight of the mangold root seems to depend on the seed bed. The roots were longest and thinnest on the deep-ploughed plots and were always squatter on the shallow-tilled than on the deep-tilled plots. The roots were heaviest on the deep-ploughed plots and lightest on the rototilled plots. On the rototilled and the grubbed plots the depth of tillage had no effect. The plants on the shallow-grubbed plots seemed, however, to have no reserve of strength, for they could not make better growth if given more room, while those on the deep-grubbed plots could make some use and those on the ploughed or rototilled plots appreciable use of extra space.

(4) Weeds tend to accumulate on the rototilled and the grubbed plots since neither grubbers nor rotary cultivators carrying tines mounted on a horizontal shaft can bury weeds and weed seeds in the way that the plough can. If the land is fairly clean and in good heart this probably does not matter for several years, but it prevents either of these from completely displacing the plough.

(5) A subsidiary result that emerged from these experiments is that if a thin crop is given a nitrogenous top dressing, the fertilizer may benefit the weeds more than the crop.

1. The numbers of bacteria and fungi in a newly-made Stilton may rise to the enormous number of 1000 to 3000 millions per gram in the first week.

2. There is a gradual fall in the numbers up to the time of ripeness (100 to 150 days old), when 50 to 100 millions only are found.

3. In the early stages lactic acid bacteria are most abundant. When the cheese is ripe the lactic acid bacteria are few and weakened in physiological power; Penicillium glaucum and a form of Torula are then abundant.

4. Five characteristic organisms are found in all Stilton cheeses examined, viz.:—(1) Streptococcus lacticus, (2) a short rod-shaped form of Bs. acidi lactici, (3) a species of Tyrothrix, (4) Penicillium glaucum, and (5) a round form of Torula, sometimes accompanied or replaced by an oval form.

In cheeses where starters have been used we find a large celled form of Streptococcus lacticus present.

5. Penicillium glaucum is checked in its growth by the Tyrothrix.

In the study of animal nutrition valuable information has been obtained from feeding experiments, the results of which depend upon the liveweight test. These results, however, deal only with the relative values of different foodstuffs and methods of feeding, and the accumulated data are, on the whole, not of such a nature that general physiological laws can be deduced from them. For the elucidation of such laws, it is necessary to carry out metabolic experiments by which the transformation of energy and material within the body can be studied with some degree of precision.

The recombinant genotypes generated with a potato breeding scheme cannot always be evaluated over the range of environments for which cultivar development is aimed. At the Scottish Crop Research Institute, the cultivar breeding programme aims to develop genotypes which perform well in one or more environments in the UK and/or countries around the Mediterranean basin. In each of three years (1984, 1985 and 1986) between 40 and 50 potato genotypes were selected solely on their phenotypic performance in an environment just south of Edinburgh in Scotland. These were then trialled at sites in four environments in the typical ware-producing regions of England and four environments around the Mediterranean region. Despite significant genotype x environment interactions for many traits, the superior genotypes tended to perform well over a wide range of environments.

Primed continuous intravenous infusions of tracer amounts of [2·3H]gluscose were used to measure glucose entry rates before and after the administration of triamcinolone acetonide or trienbolone acetate to sheep eating 1200 g/day of chopped hay.

The intramuscular injection of triamcinolone acetonide caused hyperglycaemia with a maximum plasma glucose concentration 24 h after the injection. Twenty-four hours after the injection of 0·5 mg/kg of steroid the mean glucose entry rate rose from 1·44 to 2·14 mg/min/kg. The difference between these means is significant (P < 0·02). Twenty-four hours after injecting 0·05 mg/kg of steroid the mean glucose entry rate had risen from 1·34 to 1·86 mg/min/kg. The difference between these means is significant (P < 0·05). The intramuscular injection of trienbolone acetate (0·5 mg/kg) had no effect on plasma glucose concentration or on glucose entry rate.

These results are compared with the effect of betamethasone and are discussed in relation to the treatment of ketosis in cattle and sheep.

Symptoms of magnesium deficiency and take-all disease occurred during 1967 in wheat grown for the second year in succession on the ‘Classical’ cereal site at Woburn. Magnesium fertilizers, which cured the deficiency symptoms and increased wheat yields in 1968 and 1969, had no effect on take-all. Leaves from crops severely attacked by take-all contained less nitrogen and potassium than leaves from unattacked plants but not less magnesium. In 1969 magnesium fertilizer did not increase yields or affect takeall of spring barley on the site but, in contrast to 1968, increased potato yields. Magnesium fertilizer improved the establishment of clover, especially on soil containing least magnesium.

Soil analyses show a tenfold decline in exchangeable Mg since 1888. Losses were most from soil given ammonium sulphate and more from the site where wheat was long grown than where barley was. Differences in soil magnesium did not explain large differences in yields of potatoes or leys between blocks of the experiments.

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.

Agricultural activity involves direct interaction with the physical environment factors in the environmental context in which the activity is developed. Galicia, northwest Spain, is an environmentally heterogeneous region that encompasses territorial spaces with different levels of suitability for each agricultural activity. In barely 30 years, the production systems of the region have evolved from self-sufficiency to commercial production; however, the requirements of production for each differ greatly. During such a transformation, many farms have disappeared while other farms have conformed to the requirements of the current production systems without changing location. Decision-making in rural planning requires knowing the spatial distribution of farms, the evolution of farm distribution and the relationship between the spatial location of farms (associated with some specific environmental characteristics) and the production systems used.

The current paper describes a methodology for analysing the spatial distribution of farms and for determining the relationships between the spatial location of farms and the values of the physical environment factors that are characteristic of each spatial location. The methodology has been developed by using Agricultural Census data and is exemplified through the analysis of two crops (wheat and potato) and one farming activity (dairy farming). Results show the location of farms and the production systems used, and reveal different degrees of fit to the physical environment factors considered.

A sheep-feeding experiment was carried out to compare the influence of starch supplementation on the utilization of protein contained in a roughage (lucerne hay) and in a concentrated feed (soya-bean meal). Twelve young rams were divided into four groups, all of which received 150% of the theoretical protein requirement for maintenance. Two groups received soya-bean meal, and the two other groups were given alfalfa hay as protein source. One soya-bean group and one lucerne hay group served as control groups and received the theoretical requirement of energy, whereas the energy content of both experimental groups was raised by addition of grain to 150% of the theoretical energy requirement.

A N-balance experiment carried out with both control groups did not indicate the superiority of lucerne hay over soya-bean meal as had been found in previous experiments in which the sheep were fed diets just supplying the theoretical protein requirement. The advantage of roughage protein disappeared as a result of changes of dietary regime, such as the ingestion of protein surpluses and the reduction in the amount of cottonseed hulls.

The N retention from the lucerne-hay ration was enhanced much more than the soya-bean meal ration by the addition of maize. Biochemical analyses of the rumen oontent showed that a much higher metabolic activity of the micro-organisms was induced by feeding a lucerne-hay diet supplying 150% of the theoretical protein requirement than that induced by ingestion of a corresponding amount of soya-bean meal. It was concluded that the increased biochemical potential of the lucerne-hay diet could be used advantageously only in presence of ample amounts of soluble carbohydrates. The digestibility of the carbohydrates contained in all four diets was examined by in vivo and in vitro methods. The digestibility of crude fibre in the lucerne-hay ration was somewhat raised by the addition of maize whereas the digestibility of crude fibre in the soya-bean meal ration was considerably depressed by the addition of maize.

The digestibility of the carbohydrates contained in all four diets was examined by in vivo and in vitro methods. The digestibility of crude fibre in the lucerne-hay ration was somewhat raised by the addition of maize whereas the digestibility of crude fibre in the soya-bean meal ration was considerably depressed by the addition of maize.

1. The shape or surface form of garden and field peas may be smooth, wrinkled or dimpled, depending upon the genetic constitution. The appearance of these forms is discussed and some comments made on the manner in which the characters are transmitted and expressed.

2. The genetic formulae of the three forms as suggested by other investigators do not explain satisfactorily the results observed from numerous crossings effected by the writers.

3. The following alternative combinations are offered as forming the constitution of the commercial varieties utilised:

To produce forage crop varieties of improved quality, the plant breeder must consider both the content of the quality components and their interrelationships. The methods used to examine the interrelationships involve simple correlations and path analyses. In the path analyses a dependent variate is specified which is completely and additively determined by a number of independent variates. The amount of variation present in the dependent variate accounted for by variation in each of the independent variates is calculated. The effects of an increase in the mean content of one of the quality components on the other components in the path system is predicted.

As an example of the method, data for two years is analysed from timothy polycross progenies grown as swards and spaced plants. Primary and subsequent growths are compared.

There are inconsistencies in the interrelationships of the quality components between years and between swards and spaced plants. Although only phenotypic statistics were calculated, the findings have implications in relation to plant breeding.

Mating Wessex Saddleback with Gloucester Old Spot pigs shows clearly that the former are of the three genotypes expected if the belt pattern is primarily determined by a single dominant gene (Be). Breeding tests and measurements of belt width agree in showing that homozygotes tend to have medium to wide belts, heterozygotes tend to have medium, narrow or broken belts, while pigs homozygous for the recessive are black. Crosses of Wessex with black-spotted pigs produce black piglings with or without wide symmetrical belts depending on the genotype of the Wessex parents.

Selection of breeding pigs with narrow belts maintains a high incidence of recessive blacks. Solid blacks which are nevertheless genetically belted may occur, but if so their numbers are likely to be very small.

Evidence is given which suggests that pigmentation in the skin and hair of Wessex × Large White pigs is much reduced if the Large White parents have blue eyes.

Diallel crosses, without reciprocals, were made between two strains resistant to leaf curl and two susceptible strains as part of a breeding programme for leaf curl resistance. F1, F2, F3 and backcross progenies were studied. Results revealed that leaf curl resistance, previously described as polygenic, is controlled by a major dominant gene designated as Vr1. The presence of minor modifier genes was also indicated.

Intake and digestion by swamp buffaloes (Bubalus bubalis) and crossbred cattle (Bos indicus × B. taunts) of a range of diets were measured in two experiments conducted in north Queensland in 1988. In Expt 1, four animals of each species were offered rice straw ad libitum with a supplement of minerals and urea. The four dietary treatments were (i) no concentrates, (ii)cracked rice grain (900 g/day), (iii) cracked rice grain (900 g/day) plus sunflower seed meal (900 g/day) and (iv) as for (iii) but with 50% of the sunflower seed meal treated with formaldehyde solution. In Expt 2, the same animals were offered two legumes, lablab (Lablab purpureus) and verano (Stylosanthes hamata cv. verano), and two grasses, sorghum (Sorghum bicolor × S. sudanense) and pangola grass (Digitaria eriantha). In Expt 1, voluntary intake of organic matter of buffaloes was 1·22 that of cattle. Concentrate supplementation increased organic matter digestibility and total intake, but did not affect straw intake. Intake of supplements by cattle was poor in the absence of sunflower seed meal. In Expt 2, intake and digestibility was similar in both species but was higher in animals given sorghum compared with the other forages. Total time spent chewing for both species and all diets ranged between 163 and 244 min/kg intake of plant cell wall constituents. The fractional rate of fluid flow from the reticulorumen and the concentration of propionic acid in the rumen fluid of buffaloes were consistently higher than in cattle in both experiments. Cotton and rice straw, placed in polyester bags in situ in the reticulorumen, were more extensively fermented in buffaloes than in cattle in Expt 1. In contrast, there were no differences between animal species in fermentation rates of cotton and ground diets in situ in Expt 2, but a relationship was observed between the relative fermentation of cotton and the relative digesta retention times in the reticulorumen in the two animal species. Microbial biomass, estimated as microbial dry matter per kg dry matter in the reticulorumen, was less (P < 0·05) in buffaloes than in cattle in Expt 1; higher concentrations of protozoa were observed in buffaloes than in cattle in Expt 2. Digesta load in the reticulorumen of buffaloes was c. 0·88 that of cattle. In Expt 1, digesta load was inversely related to digestible organic matter intake. The results were consistent with the hypothesis that energy metabolism and digesta load in the reticulorumen interact in the regulation of roughage intake, but it appeared that the lower loads measured in both species in Expt 2 indicated the operation of an unidentified limitation to intake.

Seventy-two (thirty-six hogs and thirty-six gilts) Large White type weaner pigs were individually and restrictedly fed four diets (as wet mashes) containing high levels (85% in the starter diets and 90% in the finisher diets) of either maize, sorghum, wheat or barley. Thirty-six pigs (nine per treatment) were slaughtered at 120 lb (54 kg approximately) live weight at the end of the period in which the starter diets were fed and the remaining thirty-six at 200 lb (90 kg approximately) live weight at the end of the period in which the finisher diets were fed.

In the starter period the growth rates and food conversion efficiencies of the pigs fed the barley- and wheat-based diets were similar but taken together were slightly superior to those of the pigs fed the maize- and sorghum-based diets. Based on determined digestible energy values the caloric efficiency of live-weight growth was significantly better for the barley-based diet than for all other diets. At a slaughter weight of 120 lb the killing out percentage of the pigs fed the maize diet was significantly higher than that of the pigs fed the barley and wheat diets. Iodine numbers of inner and outer backfats were significantly higher in pigs fed maize than in those fed sorghum and wheat and in those fed barley compared with those fed wheat. There were no other differences in carcass measurements or in the percentages of lean, fat and bone dissected from the carcasses. However, the pigs fed barley had (1) significantly smaller middle regions and (2) as percentages of the total tissue within the body, significantly less fat in the middle region but significantly more fat in the shoulder region, than did any of the other pigs.

In the finisher period the pigs fed the barley- and wheat-based diets grew significantly faster and converted their food and digestible energy of that food significantly more efficiently than did the pigs fed maize and sorghum. The caloric efficiency of live-weight gain was also significantly greater for the barley-fed pigs compared with those fed wheat. When slaughtered at 200 lb live weight, with the exception of backfat iodine numbers, where identical differences to those recorded at 120 lb were found, there were no significant differences in carcass measurements. On dissection the barley-fed pigs had significantly more lean and significantly less fat in the carcass than did any of the other pigs.

The effect of different rates (0–140 kg/ha) of nitrogen fertilizers on soil cyanobacteria and rice crop performance were studied in a rice-cropping system on an alkaline Fluvent soil at Valencia, Spain, during three consecutive crop seasons (1990–92). The results showed that the rice fields of Valencia favour the development of N2-fixing cyanobacteria. Nitrogen fixation varied during the cultivation cycle, reaching its highest values at the maximum tillering stage, 5–6 weeks after sowing, and showed a positive correlation with the abundance of cyanobacteria and a negative correlation with the amount of N fertilizers used. Grain yield increased with increasing amounts of N fertilizers up to 70 kg N/ha. N rates appeared to affect grain yield by causing variations in the number of panicles/m2. Leaf chlorophyll readings at the end of the tillering stage were positively correlated with the number of panicles/m2, suggesting that it could be a useful parameter for predicting productivity. There was a significant increase in the N uptake of the rice but a decrease in the apparent N recovery and Nuse efficiency of applied fertilizer N, with the application of increasing rates of N fertilizer. In all instances, except in plots fertilized with 140 kg N/ha, the amount of N removed by plants was significantly higher than that applied as N fertilizer. The differences were positively correlated with the values for N fixation, suggesting a significant contribution by N fixation to rice production. These results show that a rational use of biological N fixation, in combination with inorganic N fertilization, would permit the input of N fertilizers to be reduced by c. 50% without any significant loss of productivity and with an ecological benefit for the whole ecosystem.