One side of each of 51 carcasses of Hereford, Angus, Friesian and Charolais cross-bred steers was dissected and the weights of individual muscles and total carcass muscle were obtained. The percentage distribution of total carcass muscle weight in muscles and in. standard groups of muscles was determined. In addition, the percentage distribution of total carcass muscle weight in wholesale cuts was determined from the weights of whole and part muscles specified as comprising the respective cuts.

Minor breed differences only were found in muscle weight distribution among muscles, groups of muscles and wholesale cuts. Similarity of muscle weight distribution in the different types of carcasses studied shows that carcass shape is not associated with differences in the distribution of muscle weight in wholesale cuts.

Influence of season on the terpene composition of Pinus halepensis and Pinus sylvestris was investigated. The essential oil of twigs and needles from a preselected plot of pines was investigated from October to June. In P. halepensis, the average composition during this time was 27·2% α-pinene, 65·0% sabinene, 7·2% 3-carene and 0·5% β-pinene in the essential oil of twigs; 32·1% α-pinene, 35·9% sabinene, 18·5% terpinolene, 4·3% 3-carene, 3·1% β-pinene and 6·1% thujene, limonene, β;-phellandrene and γ-terpinene in the essential oil of needles. In P. sylvestris, the average composition was 49·2% α-pinene, 30·1% sabinene, 14·9% β-pinene and 7·9% limonene in the essential oil of twigs; 69·5% α-pinene, 14·9% camphene, 9·1% β-pinene, 3·6% sabinene and 2·8% limonene in the essential oil of needles. The maximum amount of sabinene coincides with the minimum of α-pinene, both in twigs and needles essential oil from P. halepensis and P. sylvestris. The month-to-month changes in the oil composition are statistically significant for the most part. It is of interest to point out the decrease of sabinene content of needles essential oil in comparison with the twigs essential oil, with the simultaneous increaseof terpinolene in P. halepensis and camphene in P. sylvestris.

A dynamic model has been derived to predict the day-to-day changes in the growth and nutrient composition of crops grown in the field with different levels of nitrogen and potassium fertilizer. Equations are included in the model to represent processes such as re-distribution of nutrients down the soil profile after rain or evapotranspiration, transformations between the various forms of potassium, transport of potassium ions through the soil to the roots and the dependence of growth and nutrient uptake on incoming radiation, plant composition, and soil water stress.

The model was tested by using it to forecast the responses of a test crop, cabbage, to fertilizers in four separate field experiments at WeUesbourne. From data describing the initial soil conditions and weights of the plant, the soil and crop characteristics and the daily weather conditions, the model correctly predicted the pattern of responses in each experiment, although, in some instances the absolute values of the theoretical and experimental yields differed somewhat. Of special significance was the ability of the model to forecast the effects of different weather conditions on crop response and the interactions between the effects of N and K fertilizers on the growth and chemical composition of plants.

Fungicide applications in Malawi have shown improvements in groundnut kernel yield. Improved fertility of sulphur-deficient soils contributes to such gains when sulphur dust is used as the fungicidal agent. Application of sulphur alone to deficient soils lowered the oil/protein ratio of kernels, whereas a singular fungicidal effect raised the oil content, probably through delayed plant maturity.

Diets containing 10·5, 13, 15·5 or 18% protein were formulated by progressively replacing barley by a 2:1 mixture of soya-bean meal and fish meal. Each diet was given at three levels of intake proportional to (body weight) 0·73. A total of 144 pigs were used at two centres.

Growth rate increased with food intake at each protein level, but to the greatest extent with the 13% crude protein (CP) diet. Growth rate also increased with protein level; the results suggested that there would be no further improvement above 18% CP. The effects of protein concentrationon food conversion generally reflected those on daily gain.

Carcass fatness, estimated by both midline and introscope measurements of fat thickness and by specific gravity, increased significantly with the intake of all but the 18% protein diet. When theeffects of food intake were taken into account, carcass fatness increased steadily with reductions in protein level down to 13%; the reduction from 13 to 10·5% produced a much greaterincrease in fatness.

The reductions in daily food intake necessary to achieve equal carcass fatness as protein level wasreduced were of the order of 0·1 kg per 1% CP from 18% to 13% CP, but ofthe order of 0·3 kg per 1% CP below 13%.

Differences between the sexes were greatest at high protein concentration; significant differences between the centres were found only with the low protein diets.

S. 24 perennial ryegrass, containing 2·9 g nitrogen/100 g D.M.>, was conserved by freezing (to represent the fresh material) or by drying. Three dehydration treatments were imposed, comprising low temperature (inlet temperature 145 °C) high temperature (inlet temperature 900 °C) or oven drying (100 °C for 18 h) and in addition part of the high temperature dried grass was treated with formalin (1 g/100 g crude protein) prior to feeding.

The digestion of the energy and nitrogen components of all diets was investigated using sheep fitted with re-entrant cannulae at the proximal duodenum and terminal ileum.

Dehydration and formalin of the grass reduced nitrogen solubility and apparent energy and nitrogen (P < 0·001) digestibilities but led to increased quantities of nitrogen entering the small intestine (P < 0·01) compared with the frozen diet. A significant relationship describing nitrogen transformations was established: Y = 165–1·13X (r = –0·98, P < 0·001), where Y is g nitrogen entering the small intestine per 100 g N consumed and X is dietary nitrogen solubility. All dried diets showed increased losses of nitrogen within the small intestine compared with the frozen diet, the largest values being observed on the oven-dried and formalin-treated diets.

Neither total VFA production within the rumen nor overall cellulose digestibility was influenced by dehydration, but on the formalin-treated diet there was a marked shift of cellulose digestion from the rumen to the caecum and colon compared with the other diets, associated presumably with the large reduction in protein solubility on this diet.

Dehydration improved the efficiency of conversion of ruminally digested energy to VFA energy within the rumen, and in relation to the nature of the total absorbed nutrients a significant relationship was established:

Y = 30·97–0·22X (r = –0·98; P < 0·001),

where Y is g digestible crude protein lost in the total intestines per 100 g digestible organic matter intake and X is dietary nitrogen solubility.

Application of methyl decanoate to a potato crop about the time of tuber initiation reduced the total yield and the yield of tubers in the grade 2·5–5·5 cm though neither of these reductions were significant. However, application of 2,3,5-triiodobenzoic acid increased the yield of tubers 2·5–5·5 cm by up to 20% while having no significant effect on total tuber yield. This change in the tuber size distribution was due to a more even partition of photosynthate between tubers and not to an increase in the total number of tubers.

A number of studies on sodium hydroxide treatment of rice hulls and straw are reported. Alkali levels ranged from 0 to 100 g NaOH/100 g for hulls and from 0 to 50 g NaOH/100 g for straw.

Effects of prior grinding, prior irradiation with gamma rays (0–50 Mrads), alkali reaction time (0–24 h), neutralization of excess residual alkali with acids, and rinsing effects were studied in terms of increased salt (ash) content, test material solubility in water and in vitro and in vivo (terylene bag) fermentation.

Moderate increases in solubility and digestibility of straw followed irradiation but not for hulls. Major increases were found for irradiated straw further treated with alkali but hulls were little affected by 5 g NaOH/100 g D.M. except at the 50 Mrad level. Nutrient fortification of inocula media did not help dissimilation. Grinding had little effect on degradation of alkali-treated hulls. Straw responses were greater than for hulls.

Alkali treatment removed encrusting silica and lignin from rice hulls and increased in vitro and in vivo digestibility. Above levels of 12·5 g NaOH/100 g dry matter in vitro digestibility was depressed unless residual alkali was neutralized. Alkali-treated hulls were reduced in silica content better by rinsing or by no neutralization and no rinsing: neutralization or neutralization followed by rinsing were less effective. Lignin was best removed by alkali or alkali and acid without rinsing. Alkali reaction time on hulls was not critical, but alkali concentration was.

Animal trials indicated useful intake and digestive responses to alkali-treated rice hulls. Raw rice hulls were rejected by sheep.

When fed in a mixed diet with lucerne chaff (40% whole rice hull, 60% lucerne chaff) daily voluntary intake of rice hull dry matter was 345 g (nil NaOH); 361 g (10 g NaOH/ 100 g rice hull); 193 g (20 g NaOH/100 g rice hull) with apparent dry-matter digestibility values for the hulls of 20%, 41% and 51% respectively.

Studies were conducted to determine possible leaching or fixation problems in growing sudangrass (Sorghum Sudanese Stapf.) when urea, ammonium sulphate plus triple superphosphate, and ammonium polyphosphate fertilizer were applied as a seed-bed application to the very sandy soils of the Libyan Sahara near the Kufra Oasis. The effectiveness of the nitrogen source was measured by plant colour, leaf analysis, and seedling height.

The urea nitrogen plus single superphosphate when applied and watered-in did not supply enough nitrogen to obtain a vigorous green seedling compared with ammonium polyphosphate (21% N, 53% P 2O6), which produced excellent vigorous green seedlings. The ammonia source supplied more nitrogen than the urea imder the conditions of these trials.

The application of urea 1, 2, 4, and 8 days before sowing was inadequate in supplying nitrogen to meet the early demand of the sudangrass seedlings. Sudangrass seedlings after 26 days were only 5–6·3 cm tall. With a seed-bed application of 36–72 kg N/ha as ammonium sulphate under comparable circumstances, sudangrass seedling height was 21·7 cm. The plants receiving no nitrogen applied before sowing were 6·7 cm high, similar to those which received urea.

Under these virgin sandy soil conditions, the ammonium sulphate and ammonium polyphosphate (21% N, 53% P2O5) fertilizers applied to the seed bed were retained within the root zone in sufficient amounts to give a vigorous, non-deficient sudangrass seedling. Nitrogen from urea was deficientand presumed leached beyond reach of the seedling root when applied to the seed bed. Applied post-emergence, however, urea was a very satisfactory source of nitrogen.

In two experiments three dates for time of last irrigation were combined factorially with four rates of application of nitrogen fertilizer and two varieties of cotton. Early termination of watering (when the crop had set 70 bolls/m2) combined with heavy application of nitrogen (168and225 kg/ha) decreased fibre strength, micronaire and yarn strength, particularly in 1973. In two other experiments three frequencies of watering were combined factorially with several rates of application of nitrogen. Frequent watering (weekly) combined with heavy application of nitrogen (168 kg/ha) decreased uniformity of fibre length, micronaire and yarn strength and appearance. In both experiments application of nitrogen increased fibre length. The responses of both varieties were similar except for effect of nitrogen on micronaire. Application of nitrogen decreased the micronaire of Deltapine 16 more than that of Acala 1517 BRI.

The response of the fibre properties to variation in crop nitrogen and water supplies are interpreted in terms of the effects of these factors on (i) the intrinsic fibre properties of bolls maturing at the same time, (ii) the change in the fibre properties of bolls maturing progressively later in the season, (iii) the proportion of total yield contributed by bolls maturing at different times and (iv) delay in harvest and consequent variation in exposure to weather prior to harvest. Yarn strength did not respond as much as fibre properties to the experimental treatments and in particular did not reflect the influence of weathering on fibre properties to the degree anticipated.

The energy cost of nesting activity and oviposition of hens in different environments has been determined.

The oxygen consumption of hens on a wire floor reached a peak during the last 15 min before oviposition. However, the oxygen uptake of hens accustomed to a litter floor had fallen to a minimum at this time.

The energy cost of expelling the egg is minimal. There is a good correlation between the locomotor activity and the heat production.

The variations in heat production and body temperature on different types of floors are explicable by the differences in nesting activity.

Carcass data for 424 castrated male lambs, comprising seven breed-type groups, were used toevaluate a series of linear measurements, subjective scores and the lean content of sample joints as predictors of percentage lean in carcass. The groups represented the main types of British lamb and mean carcass weights ranged from 12·8 kg (Welsh Mountain) to 20·8 kg (Lowland Longwool). Lambswere selected from commercial abattoirs to cover the ranges of fatness and conformation normally found in practice within each group. The pooled within-group S.D. for percentage lean was 3·70 and theoverall S.D. (ignoring groups) was 3·96.

Predictors were compared in terms of precision and the stability of their prediction equations. Of the characteristics measured on the intact carcass, subjective scoring of external fatness gave the most precise prediction both within groups and overall (R.S.D.within = 2·82, B.S.D.overall = 3·17). Fat thickness over the eye muscle (0) was the best predictor among those taken on the quartered carcass (R.S.D.within = 2·76, R.S.D.overall =3·00). The most precise individual predictors were percentage lean in the best end neck and shoulder joints (R.S.D.within = 1·51 and 1·59 respectively). Among pairs of predictors not involving dissection, the combination of C and percentage kidney knob and channel fat in the side gave the most precise prediction (R.S.D.within = 2.51, R.S.D.overall = 2·68). The stability of the prediction equations between groups tended to increase with the precision of the predictors. Among the more precise predictors, the equation for percentage lean in the leg was a notable exception, being particularly variable from one group to another.

Merino sheep were given abomasal infusions of (i) zein (80 g/day), (ii) zein (80 g/day) supplemented with L-lysine (6 g/day), L-tryptophan (1 g/day) or lysine and tryptophan together, or (iii) L-leucine (20 g/day). Effects on wool growth (length growth rate, fibre diameter, fibre volume growth rate and mass of wool grown) and on plasma amino acids were measured.

Zein increased length growth rate and decreased fibre diameter; on average the volume growth rate and mass of wool grown were not significantly altered. The addition of tryptophan to the infusion of zein did not significantly alter wool growth, whereas the addition of lysine significantly increased all aspects of wool growth. The responses to these treatments were rapid and were adequately assessed during 12-day infusion periods. The infusion of leucine did not cause any appreciable changes in wool growth.

Leucine supplementation increased the concentration of leucine in blood plasma about six-fold. Zein decreased the concentration of lysine and ornithine in plasma and increased the concentration of several essential amino acids; leucine was increased about seven-fold. The addition of tryptophan to zein had no effects on plasma amino acids, whereas lysine decreased the concentration of several amino acids in plasma and markedly increased lysine.

Measurements of O2 consumption (Vo2), CO2 production (VCO2) evaporative water loss and rectal temperature (Tr) have been made and metabolic heat production (H), evaporative heat loss (—E) and respiratory quotient (RQ) calculated with individual and groups of 1-day-old chicks at constant ambient temperatures (To) in the range 20—43 °C and 80 or 20% relative humidity (R.H.).

Minimal metabolism (10·7 kJ/kgJ/h) occurred at 35 °C.

One-day-old chicks act as heterotherms outside the zone of minimal metabolism since neither H nor —E are sufficiently developed mechanisms to maintain homeothermy.

Huddling allows chicks to maintain a higher TT at a lower H per unit metabolic body size.

Reducing E.H. from 80 to 20% raised the upper temperature survival limit (UTSL) from 41·5 to 43 °C.

Panting was initiated when Ta = 38 °C and Tr was between 39·5 and 39·9 °C.

Midas, a barley variety very susceptible to brown rust (Puccinia hordei), and two less susceptible varieties (Julia and Mazurka) were given three amounts of nitrogen (50, 100 or 150 kgN/ha) either at sowing (in March), in May, or half at each time. Benodanil sprays were applied to one half of each plot in June and again in July to control brown rust. Brown rust became more severe in 1973 than in 1974 and was most severe on Midas with 150kgN/ha. In 1973, there was most brown rust where all or part of the nitrogen was applied in May, but in 1974 there was least brown rust where all the nitrogen was applied in May, probably because dry weather limited its uptake.

In 1973, when ample rain fell in spring and summer, grain yield was increased more by nitrogen given in May than in March, especially when benodanil was given. In 1974, little rain fell until July and then March nitrogen increased grain yield most whether or not benodanil was given. Top dressing of N (in May) produced a smaller straw yield than seed-bed dressing did in each year.

Benodanil spray much decreased brown rust and increased yield of grain, but not of straw; the increase was greater in 1973 than in 1974, when brown rust was less abundant. Benodanil increased yields of all varieties, but that of the rust susceptible variety, Midas, most. Benodanil increased grain yield more, as more N was given to the barley, and more with N given in May than in March. It increased the amount of N removed by the barley grain, but not by the straw.

The net assimilation rates (NAR) of three genotypes of cotton differing in their growth habit were studied under different spacings. The NARs of a very bushy type, G 67, and a comparatively less spreading type, IAN 560, were the same but that of a compact type, IAN 579, was twice as much when the leaf area index (LAI) was one. Though subsequently in G 67 and IAN 560 NAR under varying spacings either decreased less rapidly or remained steady, the decrease was nearly Hnear with increasing LAI. However, for IAN 579 dependence of NAR on LAI was generally positive indicating genotypic improvement. Under different spacings the leaf-density dependance of NAR appeared to have been decreased in IAN 560, but was nearly absent in IAN 579 with more efficiency towards increasing the yield of seed cotton.

Thirty-four (13♂, 21♀) entire cross-bred lambs were suckled on reconstituted, spray-dried cows' milk from 2 days of age for varying periods of time up to 18 weeks before being weaned on to solid food or slaughtered to determine chemical composition. The body composition of each sheep (water, fat, protein, energy) was also estimated from the tritiated water (TOH) space at 3-weekly intervals during milk feeding, at intervals of 5–8 weeks subsequently and at slaughter. Comparison between. TOH estimates and whole body analysis confirmed the accuracy of the previously-derived prediction equations.

The relationship between each of the various body components and body weight for individual sheep during milk feeding was described by a ‘bent’ (non-rectangular) hyperbola. There were no substantial differences between animals in either the position or slope of the lower asymptote nor in the slope of the upper asymptote. There were, however, substantial differences in the point of intersection of the two asymptotes both within and between sexes. The mean intersection points for males and females were 17·7 and 14·4 kg body weight respectively.

Sheep weaned at body weights of 11–16 kg subsequently followed the previously defined pattern of growth. Weaning at higher body weights (21–34 kg, body fat not less than 5·5 kg) resulted initially in both fat and/or body weight loss. In the final fattening phase of growth early- and late-weaned sheep of the same sex had similar body composition but females were fatter than males.

Three buffalo calves and four Holstein x Hariana cross-bred calves of 4–6 months of age were fed for 21 weeks either on a normal protein ration according to National Research Council (1966) standard or 25% below or above it. The scheme of feeding was as follows:

Blood urea was determined every week from 6th to 21st week except in 10th, 14th and 15th week. When the animals attained the age of 15–17 months, their blood urea was again determined.

Blood urea of buffalo calves was found to be significantly higher than that of cow calves under similar conditions of feeding from 4 to 11 months of age. This difference disappeared at 15–17 months of age. Probable causes for this difference between species are discussed. Blood urea in both species tended to increase on high protein and decrease on low protein rations.

The effect of soil salinity (ECe range 2–9 mmhos/cm) on the growth of and ion uptake by barley, sugar beet and broad beans (crops increasingly sensitive to salinity) was investigated in a glasshouse experiment.

Barley and sugar-beet yields benefited from the added Na in the soil but broad beans were always adversely affected. Changes in growth and ion uptake are discussed in terms of Na:K synergism and antagonism.

Sodium:potassium antagonism was observed in barley just after germination, and in sugar beet throughout growth, but not in barley at other growth stages nor in broad beans. Greater Na uptake promoted increases in dry-matter yields of all plant parts with barley and sugar beet, indicating that Na played a specific role in their metabolism. In sugar-beet roots, sugar concentrations and dry-matter yields increased with added Na by half as much more than without added Na, suggesting that Na is an essential nutrient.

We conclude from our experiments that the effects of salinity caused by Na salts when water is not limiting, is related not only to plant species but also to their stages of growth.

Fraction 1 protein (18S) can be isolated in large quantities (order 100 g) in a soluble state by heating lucerne juice, adjusted to pH 6·7 to 6·9, from a Pirie extractor to 63 °C for 10 min. Low speed oentrifugation (2500 g) removed coagulated chloroplast fragments and most of the heat-denatured Fraction 2 proteins. Fraction 1 (18S) protein (> 95% pure) was purified from low molecular weight materials (sugars, phenolics etc.) by ammonium sulphate fractionation and gel filtration on Sephadex G-75 gels.