1. Net pasture dry matter production and available pasture dry matter were measured over 3 years in a small-scale replica of the study of the effects of dairy cow grazing management and stocking rate reported by McMeekan & Walshe (1963).

2. The four treatments were

(i) Controlled rotational grazing, light stocking rate (0.95 cows/acre).

(ii) Controlled rotational grazing, heavy stocking rate (1.19 cows/acre).

(iii) Uncontrolled, set stocked grazing, light stocking rate (0.95 cows/acre).

(iv) Uncontrolled, set stocked grazing, heavy stocking rate (1.19 cows/acre).

3. The pasture measurement technique employed measured net pasture production (gains through new growth minus losses from all sources). It is argued that this parameter, rather than absolute pasture production, governs the changes in the dry matter feed supply to the grazing animal.

Ninety-seven Awassi ewes were included in three experiments. The ewes were milked twice daily, and also suckled lambs. Three different suckling regimes (12 hours per day, 4hr. and residual milk only) and three weaning times after lambing were compared.

1. Dry-matter intake, pasture utilization and grazing pressure were studied over 3 years on a small-scale replica of a dairy cow grazing management x stocking rate trial.

2. The four treatments were:

(i) Controlled rotational grazing, light stocking rate (0.95 cow/acre).

(ii) Controlled rotational grazing, heavy stocking rate (1.19 cow/acre).

(iii) Uncontrolled, set stocked grazing, light stocking rate (0.95 cow/acre).

(iv) Uncontrolled, set stocked grazing, heavy stocking rate (1.19 cows/acre).

3. Mean D.M. intakes were: (i) 29, (ii) 21, (iii) 28 and (iv) 21 lb./cow per day. D.M. intake was reduced on average by 7 ± 2.1 lb./cow per day at the higher level of stocking.

1. On twelve occasions covering a complete seasonal cycle rumen mierobial end-product concentrations were measured in a group of sheep allowed to graze a pasture for 1 hr. Considerable differences were obtained in the rises in total volatile fatty acid and ammonia after feeding, in average rumen protein nitrogen and in free mierobial count.

2. Seven samples of fresh herbage wfere fed to groups of sheep in pens at different levels of intake. Increase in feed intake with five of the herbages produced significant increases in rumen ammonia and total volatile fatty acid and with one herbage there was a significant increase in protein nitrogen. Free mierobial count was measured after feeding three herbages and was found to be independent of intake level.

1. Pasture parameters have been correlated with animal production parameters from a trial in which two management systems (‘controlled’ and ‘uncontrolled’ grazing), each at two stocking rates (0.95 and 1.19 cows/acre), were compared.

2. Per acre butterfat production was positively related to percentage utilization of available D.M., but negatively related to yield of available D.M.

3. Per cow butterfat production was significantly and positively correlated with yield of available D.M. in the two months after calving (August and September) and in the penultimate month of lacta-tion (April), but this correlation was not significant in other months.

4. It is concluded that management system was as important as stocking rate in increasing the utilization of pasture and animal production from pasture.

1. Five experiments, each with three steers, were made in which the same diet was given in three different amounts and energy and N metabolism measured. Fasting metabolism was also determined in each experiment. The experiments were made when the steers were 15, 31, 35, 46 and 81 weeks of age.

2. Age of animal had no effect on the apparent digestibility of the diet, methane production and urine energy loss from or on the metabolizable energy of the diet. The efficiency with which the metabolizable energy of the diet was used to maintain the animals and to promote energy retention by them was also unaffected by their age. The determined efficiencies were those to be expected from the results obtained in experiments with mature ruminants.

3. Retention of N was more efficient in the younger animals, and the composition of the gains showed that protein energy accounted for 30.5% of the total energy retained in the 15-week-old animals and 24.8 % in the animals 81 weeks of age.

The majority of Awassi flocks in Israel and throughout the Middle East are kept under primitive extensive conditions. Their main product is the lamb, and milk as a by-product is gained occasionally after weaning. A few estimates of the milk yields of these sheep may be found in the literature (Hirsh, 1931; Finci, 1957; Becker, 1958), however, none are based on actual measurements.

1. Three experiments were carried out on 112 Awassi lambs of both sexes, born as singles. During the first 8 or 9 weeks of their life they sucked an average of 78, 108, 53 and 50 kg. of milk per head for 12 hr. per day sucklings in a medium producing flock and 12 hr., 4 hr. and residual sucklings in a high producing flock, respectively.

Several town-refuse manures were compared with farmyard manure at Rothamsted and five other places between 1940 and 1947. The organic manures were used at 8 and 16 tons/acre with and without fertilizer nitrogen and potash. Direct and residual effects were measured on agricultural and horticultural crops.

All organic manures improved yields in the year of application, FYM most and consistently. The average percentage increases in yield produced by the pulverized refuses tested, in relation to the increase from an equal weight of FYM, were: sugar beet 22, mangolds 83, carrots, 85, potatoes 51. The corresponding figures for screened dust were: sugar beet 40, mangolds 28, carrots 41; the dust slightly depressed potato yields. Averaging all sixteen experiments on root crops, the pulverized refuses had 64% of the first-year effect of FYM and the screened dust 25%.

1. This paper provides further information on the mineral content of the milk of Clun Forest ewes, particularly those elements not dealt with in a previous paper, namely, magnesium, sodium, potassium, and certain trace elements.

2. The average composition was as follows: calcium 0.200, magnesium 0.0147, sodium 0.046, potassium 0.168, phosphorus 0.140 and chlorine 0.076%; copper 0.22, iron 0.77, manganese 0.07 and aluminium 1.7 parts per million. Where possible the results are compared with those obtained by other workers for ewe's and cow's milk.

3. Statistical analysis of the data showed that, with the exception of phosphorus, the content of major elements varied significantly during the lactation period. There was also a significant variation in all major elements between sheep.

The blood ketone body response to butyrate (2-5mM. butyrate/kg.) and glucose tolerance (1.25 mM. glucose/kg.) were studied in lambs as a function of age. Ketonemias produced by butyrate increased with age. This finding is compatible with an increased mass of ketone body synthesizing tissue, and by an increased activity per unit of tissue weight. In the period shortly after birth, blood glucose levels and glucose tolerance were high, but both of these measurements declined with increasing age and associated development of rumen function.

The yields of seed from a hybrid, one of its parents and different mixtures of the hybrid and parent were compared in the case of two different hybrids. Open-pollinated controls were included in the trial, which was sown at about the normal rate for beans. With both hybrids a mixture of 11 of hybrid to 1 of parent yielded as well as the hybrid itself and mixtures of 2 of hybrid to 1 of parent yielded in both cases about 7 cwt./acro more than the mean of the open-pollinated controls. With the higher-yielding hybrid, which had less contrast in vegetative vigour between hybrid and parent, mixtures in the proportions 5:1 and 2:1 showed declining yields, but with the other hybrid they yielded as well as the pure hybrid.

Data from one field and three glasshouse experiments are presented on the sodium and potassium contents of a number of grasses and on the effect of nitrogen, potassium, and sodium supply on these.

Large and consistent differences in sodium content exist between different genera of grasses. Potassium content may also show such differences.

Environmental factors which affect sodium content are the supply of nitrogen and potassium. Increasing nitrogen in the growth medium raises the sodium content, increasing potassium lowers it.

A grass with a potentially high sodium content will show a wide range in this element depending on the environment. One with a low sodium potential will remain always low, not unaffected by environment but affected within a more restricted range.

The nutritive evaluation of range forages often is limited by the size of the forage sample available, by the difficulty of determining both the quantity and quality of the forage eaten, and by the labour and other costs of making total faecal collections in digestion trials under range conditions. Microdigestion techniques utilizing either the nylon bag in the rumen (hereafter referred to as nylon bag in vivo) and artificial rumen techniques (hereafter referred to as in vitro) have been reviewed by Annison & Lewis (1959), Barnett & Reid (1961), and Johnson (1963). Forage evaluation could be greatly simplified if such microdigestion techniques could be utilized under range conditions. Following preliminary studies (Van Dyne, 1962), the research reported in this paper was undertaken to evaluate these techniques under both range drylot conditions in studying the intake and digestion of forages. Other aspects of these trials are reported elsewhere (Van Dyne & Weir, 1964; Van Dyne & Meyer, 1964; Van Dyne & Lofgreen, 1964; Van Dyne & Heady, 1965a, b).

During the period 1959-62 liquid digested sludge was applied to grass to supply nitrogen at rates similar to those normally recommended to farmers. The responses were compared to those produced by equivalent inorganic fertilizers.

Liquid digested sludge gave as large an increase in dry matter as equivalent fertilizers. At the low rate of application the mean dry matter increase was 15.2 lb./lb. of applied nitrogen, and at the high rate the mean response was 11.0 lb. dry matter per lb. of nitrogen.

On one site, all treatments reduced the clover percentage, the high rate more than the low rate. Sludge treatments reduced the clover percentages less than equivalent inorganic fertilizers.

Dinoseb and TCA were successfully used to control weeds in potatoes by Robertson (1960), and Wood, Sutherland & Stephens (1960). Since then many investigations have been carried out on the use of newer herbicides including the bipyridils, triazines and substituted ureas. The results of a number of these studies, presented at the Seventh British Weed Control Conference (1964), suggested that herbicides might give effective control of annual weeds in potatoes under a range of British conditions. Yields of marketable ware following herbicide treatment were similar, in general, to those obtained following standard post-planting cultivations, but occasionally the yields after herbicide treatment were either as much as 20% higher or lower than the controls. The performance of the herbicides was related mainly to weed flora, soil type and amount and distribution of rainfall.

A screening technique is described for determining the resistance of seedling cereal plants to Cercosporella herpotrichoides by observing the rate of penetration of successive leaf-sheaths by the pathogen pathogen growing from an artificially colonized 'cylinder' of straw placed over the emerging coleoptile.

In a factorial trial comparing liquid digested sludge with equivalent water, and inorganic nitrogen, phosphorus, and potassium fertilizers, almost all the effects observed could be attributed to the uptake of nitrogen or potassium.

Over the 2-year period of treatment application, liquid digested sludge and equivalent inorganic fertilizer nitrogen and potassium gave similar responses of 22.3 and 23.8 lb. dry matter per lb. of nitrogen, and 59 lb./acre K increased the response to inorganic nitrogen alone by 5.4 lb./lb. of nitrogen.

Over the 2-year period of treatment the amount of potassium absorbed by herbage, in excess of that applied, was greater with fertilizer nitrogen than with liquid digested sludge. Added potassium had no direct effect on crude protein production. Liquid digested sludge and inorganic nitrogen fertilizer increased crude protein to a similar extent.

A study was made of phenotypic correlations between seed yield and some other traits of determinable value in two bred varieties of meadow fescue. Seed yield and such characters as time of flowering, plant height and dry-matter production of spaced plants in October and at the time of anthesis were found to be closely associated.

The method of path coefficient analysis was used to study the interrelationships of seed yield and its components in the causal system: fertile tiller and floret numbers, percentage fertility and thousandseed weight. This analysis corroborates the result of simple correlations in showing the importance of fertile tiller numbers and fertility as major determinants of seed yield.

During 1962-65 investigation was carried out at Cambridge on the effect of irrigation combined with cutting treatments on vegetative growth, inflorescence formation and yield of seed of S184 white clover sown on gravelly loam of poor waterholding capacity.

Under the conditions described, irrigation was beneficial for seed production when it was applied between the period of shutting-up and the start of clover flowering. An excess of water either from natural precipitation or irrigation during the flowering period had, however, a harmful effect on seed production.

Apart from the first year, the effect of differential cuttings up to the early bud stage was insignificant on the seed yield. The interaction cutting x irrigation was not significant.

The author is grateful to Mr F. R. Home, Director of the National Institute of Agricultural Botany, for opportunities and facilities provided for this experiment.