An experiment to measure the effects of cold conditions upon heat production in young sambar (Cervus unicolor) and red deer (Cervus elaphus) was conducted during winter 1994, at Massey University, Palmerston North, New Zealand (NZ), using four young animals of each species. Animals were fed a pelleted concentrated diet (total N 29g/kg DM; 11·9MJ metabolizable energy (ME)/kg DM) at approximately maintenance ME intake (MEI). Hair coat characteristics were measured on samples cut from a patch on the mid-side of the body. Pairs of animals (one sambar and one red deer) were confined in two open circuit calorimetry chambers (one deer in each chamber) for 18-day periods, and oxygen consumption was measured at 20 and 5 °C, with and without simulated wind (6 km/h). Heat production was calculated as 20·5 MJ/1 oxygen consumed.

Hair coats of sambar deer were less deep, lighter in weight (g/m2) and contained a lower proportion of undercoat than those of red deer. Fibre length of both guard hairs and undercoat were shorter in sambar deer than in red deer, whilst fibre diameter of both guard hairs and undercoat was greater in sambar deer. Heat production (HP) at 20 °C was lower in sambar than in red deer (P <0·05; 0·46 v. 0·48-0·53 MJ/kgW0·75 per day). Increases in HP from 20 to 5 °C and from 20 °C to 5 °C W (i.e. with wind effect) were greater in sambar than in red deer (P < 0·01; 34 v. 16% and 44 v. 20%, respectively). Calculated lower critical temperatures (LCT) were higher for sambar than for red deer (P < 0·10) both in the absence (0 km/h; 11·6 v. 8·9 °C) and in the presence of wind (6 km/h; 140 v. 11·1 °C). Under field conditions, young sambar deer are likely to require more shelter and better feeding during cold weather than do red deer.

The effect of seed protein content on grain yield has been studied in varieties of spring barley, oats and wheat grown under differing cultural conditions. Grain yield was affected by seed protein content in one experiment where very low yields were attained, but the effects were inconsistent. No effect was observed in two other experiments made in a glasshouse and the field. In a growth-room experiment, seed with high protein content produced more vigorous seedlings than low-protein seed; these differences were accentuated by increasing seedling age at very low nutrient levels, but decreased with seedling age at normal nutrient levels. It is concluded from the results that variations in seed protein content are unlikely to have a significant effect on yield under practical conditions.

Labelling using the stable 15 isotope of nitrogen allows a close monitoring of the fate of the fertilizer applied to arable crops. Because 15N data give direct estimates of nitrogen transformation rates, they also provide more stringent tests for N models than those based on bulk inorganic N dynamics. They may therefore point at flaws in models that had previously gone unnoticed, especially if 15N was monitored on short time steps which capture even rapid processes like nitrification.

Here we tested the simple, process-based model SUNDIAL on two such data sets obtained in Northern France under winter wheat and winter rape crops receiving various doses and forms of fertilizer N. In both experiments, microplots (≈ 1 m2 in size) within larger blocks were dressed with 2·0 atom-% enriched labelled 15N, as urea, or ammonium-nitrate as NH+4–15NO3 or 15NH+4–H–NO3. Replicate micro-plots were subsequently sampled on four occasions after fertilizer application, and 15N enrichment was monitored in plant roots and tops, and at several depths in the soil in inorganic and organic forms.

Comparison between observed and simulated data showed that, shortly after application, SUNDIAL either underestimated (rapeseed) or overestimated (wheat) the rates of crop uptake. Also, the gradual incorporation of 15N into soil organic matter was too quick in autumn and too slow in spring under the rapeseed crop. The simulation of the rapid depletion of the labelled soil inorganic N pool was correct under wheat, whereas under rape, SUNDIAL predicted an accumulation of nitrate which was not observed.

After a longer time interval (1–2 months), the simulated and observed amounts of fertilizer-derived N in the crop and in the soil became more comparable. However, SUNDIAL only accounted for part of the unrecovered labelled N. Additional measurements indicated that denitrification and ammonia volatilization were responsible for most of the losses, with discrepancies occurring because SUNDIAL failed to volatilize ammonia after fertilizer spreading. The other major source of error lay in the simulation of crop demand for nitrogen, which may be improved based on sounder eco-physiological concepts, such as that of a regulation of plant uptake by shoot biomass.

1. A preliminary study of the protein requirements of young steers of two breeds of African cattle has been described. These requirements were assessed by studying body weight changes of groups of animals fed for 140 days on rations varying in protein content.

2. There were only small differences between the breeds in their voluntary food intake while appetite seemed to be linearly related to protein content.

3. The two breeds were equally efficient in food and protein utilization.

4. Live-weight gain improved significantly as the protein content of the ration increased from 6 to 10%, but a further increase to 14% produced only a small subsequent improvement in growth.

5. Maintenance of weight was estimated to occur at a digestible protein intake of only 48% of that recommended by Brody (1945), while the required digestible protein for one pound daily gain was in agreement with the National Research Council (1950) standard.

1. An account is given of the distribution of four separate boulder clays, which form the parent materials of the soils of eastern Kincardineshire.

2. The mineral composition of the fine sand fractions of the boulder clays is given.

3. The boulder clays, notwithstanding colour similarities, have been shown by mineralogical examination to be distinct.

4. The middle boulder clay, largely influenced by rocks of Old Red Sandstone age, is shown to have a higher proportion of ferromagnesian silicate minerals than soils from glacial drifts similarly derived elsewhere in Scotland.

Seventy-four field experiments on the nitrogen requirement of sugar beet were made in eastern England in. 1966 to 1974. Considerable differences in sugar yield response to nitrogen were found between the six soil types used, and these differences were found (on five of the six soils) to be related to sugar yield. Nitrogen response was large on chalk and limestone soils in Lincolnshire, intermediate on East Anglian boulder clays and least on East Anglian chalk and light drift soils. On the lighter soils (limestones, East Anglian chalks and light drifts) nitrogen response was greater with high summer rainfall than with low. Fenland silt soils were very high yielding, but nitrogen response was moderate.

Optimum nitrogen rates differed between soils, in the range 100 kg/ha on East Anglian chalks and light drifts to 180–200 kg/ha on Lincolnshire chalks and limestones.

Deploying resistant cultivars is an economical and essential management method in controlling viral diseases, and there are several mutational resources for tobacco. In the present study, the inoculation of tobacco plants with tobacco viruses was performed in a greenhouse from 2011 to 2014 to identify mutants resistant to tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). The high-throughput screening included seeding uniformly, transplanting in seedbeds, inoculating by cloth brushes and reporting symptoms based on disease indices. A total of 4000 second generation segregating (M2) mutants of tobacco cultivar Zhongyan100 were screened. Seeds from highly resistant mutant M2 plants were selected and planted separately. The M3 were grown and mutational stability was measured. For TMV, ten highly resistant plants were selected in the M2 generation and the mutation rate was 0·012%. In the M3 generation, there were seven mutants with hereditary high resistance and, according to the results of real-time polymerase chain reaction, the N gene was detected in all seven M3. Two hereditary immune M4 mutants, one of which was a male sterile line, were identified and evaluated in the glasshouse and in the field. For CMV, seven highly resistant plants were selected from the M2 generation and the mutation rate was 0·009%. In the M3 generation, there was one mutant with hereditary high resistance. The results indicate that hereditary mutants may be identified in the M4 generation and back-crossed to wild-type Zhongyan100 to identify anti-viral genes.

The modified EDTA (ethylenediaminetetraacetic acid) method of determining the ionic activities in soils developed by Norvell was used to measure Zn2+, Cu2+ and Mn2+ activities including the competition of Ca and Mg for the chelating ligand EDTA. In the Zn-EDTA system, the equilibrium mole fraction of CaL2− + MgL2− increased with an increase in pH of the soil solution, thereby leading to a decrease in the concentration of transition metal ions. In view of the pH dependence of the metal ion activities, the values of the expression pM + 2 pOH (where M may be Zn, Cu or Mn) were used to discuss the possible role of various oxides, hydroxides, carbonates, sulphides and unknown solid phases in regulating the activities of Zn2+, Cu2+ and Mn2+ ions in alkaline and calcareous soils.

1. In a 2×3×3 factorial experiment a total of seventy-two female or castrated pure Friesian, Charolais × Friesian and Welsh Black × Friesian cattle were fed individually and ad libitum on three diets from 200 lb to slaughter at 800 or 900 lb, depending on sex. The diets were ground barley (87%) and protein-mineral-vitamin supplement (13%) given with or without 1 lb of hay per animal daily, or ground maize (87%) and supplement (13%) given with 1 lb of hay daily.

2. The three breed-types differed significantly in growth rate and feed conversion efficiency. Gaining at 2·66 lb/day and converting 4·56 lb of meal into 1 lb live-weight gain, the Charolais crosses grew 7·7 % faster than pure Friesians and consumed 14·1% less meal per unit gain. Welsh Black crosses made 9·3% less rapid gains and required 7·7 % more meal per unit gain than pure Friesians. The disparity between the three breedtypes increased with increasing liveweight.

1. The fertility of three sterile bulls was restored by injections of human pregnancy urine extract (P.U.).

2. Cows which failed to exhibit oestrus were treated by injections of P.U. Three out of five cows responded within 24 hours to intravenous injections of 5 c.c. P.U. (2500 rat units) and one out of four to an injection of 3 c.c. P.U.

Two out of five cows responded immediately to a series of three intramuscular injections of 2 c.c. P.U. and one cow responded to a single intramuscular injection of 2 c.c. P.U. In addition four cows failed to respond immediately to four intramuscular injections of 2 c.c. P.U.

3. Evidence was obtained which shows that treatment with P.U. at the time of service increases the fertility of cows which show regular oestrus but nevertheless fail to conceive. It is believed that this condition is often due (a) to failure to ovulate, and (b) to deficiency of progesterone following ovulation.

We are grateful to Prof. R. Rae and Mr K. W. C. Campbell for their co-operation. Part of this work was carried out during the tenure by one of us (H.M.S.W.) of a Research Grant from the Ministry of Agriculture and Fisheries.

A 2·year grazing trial was carried out on an equatorial Themeda triandra range grassland in the Rift Valley of Kenya, at 1890 m altitude with a bimodal rainfall of 700 mm p.a., to characterize seasonal changes in the pasture and to determine the influence of climatic and management factors on forage availability and composition, grazing selection and live-weight gains on Boran steers (Bos indicus).

Fourteen categories of sampling and measurement techniques used in this work are described and some methodology problems in rangeland evaluation discussed.

For precise estimation of herbage yields in large paddocks unacceptably large plotsizes and numbers were required so an arbitrary sample of twelve 10 yd x 1 yd plots per paddock was adopted giving c.v.s of 16–50%. Subsequent sampling was limited to three contrasting treatments in the most uniform block. A ‘forceps point’ method was developed for botanical estimation of oesophageal fistula samples and provisional weight correction factors calculated. In a parallel feeding trial regressions were calculated for relating the chemical composition of oesophageal fistula samples to that of the herbage ingested.

Field experiments to study the effect of pre-sprouting, cutting seed and seed soaking in plant regulators on the number and size of seed tubers and yield of potatoes were conducted during the autumn crop seasons of 1978–9 to 1980–1. At the same seed rate, cut seed produced significantly more sprouts and stems, seed-size tubers and seed yield than the whole seed without affecting the aggregate yield. Similar effects were recorded with soaking whole non-dormant tubers in 10 mg GA 3/1 solution for 15 min before planting. Soaking whole non-dormant seed in 0·5% thiourea solution for 1 h increased the number of sprouts and seed-size tubers, giving increases in seed yield of 2·26, 2·73 and 2·65 t/ha over soaking seed in water in the three consecutive years. The corresponding increases in aggregate yield were 1·79, 1·48 and 1·60 t/ha. Soaking cut seed in solutions of 10 mg GA 3/1 and 0·5% thiourea singly or in combination had an adverse effect on the yield of potatoes.

A general model of lysine deposition in cereal grains is presented. By inserting into the model values for the lysine contents of various individual protein fractions, equations have been derived which relate total lysine content to total nitrogen. The equation for barley has been used to predict the likely variation in lysine content for this species and the results are compared with published data.

The effect of a comprehensive (three-spray) fungicide programme on yield, specific weight (SW), 1000-grain weight (TGW), nutritive value and yield of both winter and spring oat grains was investigated over a 3-year period (1989–91). With winter oats, four cultivars (Aintree, Image or Pennal, Solva and Kynon), were tested at each of three sites (Gwent, Hereford and Kent). Similarly for spring oats, four cultivars (Dula, Keeper, Rollo and Rhiannon) were tested at each of three sites (Cornwall, North Yorkshire and Wales).

On winter oats, fungicide treatment produced a significant increase (P<0·05) in grain yield, but did not on spring oats. Fungicide treatment produced no significant effect on SW, TGW or nutritive value of the winter or spring oats. With winter oats, but not with spring oats, fungicide treatment produced a significant increase (P<0·05) in the yield of digestible (DE) and metabolizable (ME) energy for pigs and ruminants respectively.

The naked oats, Kynon and Rhiannon, had a significantly lower yield, higher SW and lower TGW than the other conventional cultivars (P<0·05). Their oil, fatty acid, protein, DE and ME contents were also significantly higher than the other cultivars (P<0·05). Nevertheless, the yield of protein, DE and ME tended to be less from naked oats than from some of the other cultivars tested.

On winter oats, TGW, protein content and protein yield, dry matter (DM) and fatty acid content and on spring oats, yield, TGW, ME yield, DM, oil, fatty acid, protein, DE and ME all varied between years. With winter oats, oil content and energy values were negatively correlated with yield and positively correlated with SW. With spring oats, DE and ME were positively correlated with SW.

It was concluded that, on winter oats, fungicide treatment was worthwhile in terms of grain yield, but this was not the case for spring oats. Also with winter oats, but not spring oats, fungicides gave useful increases in the yield of energy. The naked oats, Kynon and Rhiannon, had a distinct advantage in terms of nutritive value, but their low yield compared with the conventional cultivars tended to negate this benefit.

Study of the nutritional requirements of sugar cane on a Jamaican estate necessitated simultaneous experimentation with five manurial factors: sulphate of ammonia, superphosphate, muriate of potash, bagasse, and filter press mud. By adopting a one-third replication of a 35 factorial scheme, each factor could be tested at single and double levels for comparison with the absence of the factor.

The structure and confounding system of the design adopted have been described and the method of computing the analysis of variance has been explained. Fractional replication introduces special problems of interpretation, and this experiment illustrates how they may be resolved. Each fertilizer clearly benefited the crop, and several interactions appeared; some ambiguity of meaning is an inevitable concomitant of fractional replication, so that care was needed in order to assign effects to the right causes. The most clearly marked effects were:

(i) Without phosphate, nitrogen failed to produce any response; where phosphatic manuring was adequate the crop responded well to nitrogen.

(ii) Superphosphate and filter press mud were practically interchangeable as sources of phosphate.

(iii) Bagasse appears to act as a source of potash; the interaction of responses is not very clearly established, but little extra response to artificial potash occurred when bagasse was given.

(iv) No evidence was obtained that the double level of any fertilizer was superior to the single.

There was also a suggestion of a reduced superphosphate response in the presence of bagasse.

If a recommendation on manuring were to be based on this experiment, it would be that a maximum of 3 cwt. sulphate of ammonia per acre be used with either 4 cwt. 18% superphosphate and 1 cwt. muriate of potash per acre or 10 tons filter press mud and 20 tons bagasse per acre. In reality, of course, no attempt ought to be made to determine a general manurial policy from results of a single year of experimentation on plant cane at one place.

The experiment should be regarded rather as typical of what can be done than as a complete investigation of manurial needs.

Dairy cow systems based on grassland utilization are characterized by a variation of harvested forage quality from 1 year to another and a fluctuation of grass availability and quality during the pasture season. Consequently, the energy supplied by the diet – i.e., concentrates plus hay or silage in winter and grazing in summer, may not always match animal requirements. A modelling approach enables a representation of the complex relationships between the cow and pasture as they interact. A dynamic model of intake and milk production, focused on grassland utilization by the dairy cow, has been developed. The model operates in a deterministic fashion with a daily time step and is capable of dealing with a day-to-day variation in grass availability and quality at grazing as well as a constant feeding regime during the winter. The model has been built based on the theory that milk production is a result of (i) the energy requirements defined by the potential milk production and physiological status of dairy cows; (ii) the variation of energy supply by the diet; (iii) the ability of dairy cows to mobilize or store body reserves. The model was validated by comparing milk production predictions with experimental data (two groups of dairy cows in the winter time and one group at grazing). The model demonstrates a satisfactory range of accuracy (root-mean-square deviation equal to 1·8, 2·1 and 1·4 kg/cow/day). Model validations indicate that milk production predictions are sensitive to the diet offered (forage, grass and concentrate supply) and depend on dairy cow characteristics and their requirements (pMP). This model can be connected to a grass growth model in order to develop whole farm simulations.

Field studies were carried out to determine the sources of photosynthate for developing pods and to assess the effect of defoliation and flower removal at different stages on the performance of lentil. The leaves of flowering nodes were the primary source of assimilate to pods. Removal of 25–75% of leaves reduced seed yield by varying degrees depending on crop growth stage. The plants compensated for the loss of foliage to some extent, possibly through increased efficiency of the remaining leaves. One complete or 50% defoliation reduced seed yield to different extents at the vegetative, flowering, early pod formation and late pod formation stages, the greatest effect being seen at flowering and early pod formation. Plants compensated considerably by production of new leaves when defoliated at the vegetative phase. Increased moisture supply greatly enhanced the compensation ability of the lentil plants.

Removal of all flowers up to 1–2 weeks after an thesis under unirrigated conditions and up to 3 weeks after anthesis in irrigated conditions did not adversely affect the seed yield. Flower removal beyond this period resulted in a significant reduction in seed yield. Little seed yield was obtained when flower removal was continued for either 6 or 8 weeks under unirrigated conditions. The plants compensated for the loss of earlier-formed flowers by setting pods from later-formed flowers. Compensation was greatly enhanced when the crop was irrigated during the reproductive phase. There was relatively little or no effect of the deflowering treatments on the number of seeds per pod or weight per seed. The flowering period of the deflowered plants was extended and their senescence was delayed. When 25% of the flowers were removed at different intervals during the reproductive phase, seed yield was not adversely affected. An increased intensity of flower removal decreased yield but the decrease was not proportional to the degree of flower removal. The plants apparently compensated by setting new pods.

The effects of suppressing couch grass (Elytrigia repens L.), through integrated management, on soil biological quality and N and P nutrition of barley (Hordeum vulgare L.) were evaluated in a field experiment (1987–92) on a Dark Grey soil in Alberta, Canada. The management practices consisted of combinations of herbicide application, crop rotations and tillage treatments. The 3-year crop sequences consisted of continuous barley, canola (Brassica rapa L.)–barley–barley, fallow–barley–barley, and barley or canola undersown with red clover (Trifolium pratense L.)–red clover green manure–barley. In 1992, the sixth year of the experiment, soil and plant samples were analysed for nutrient content. Treatments that consisted of spring and autumn tillage only did not suppress couch grass and produced low barley yields and N and P uptake. More N was immobilized in couch grass shoots and rhizomes and soil microbial biomass with these treatments than with similar herbicide-treated crop rotations. Tillage-plus-herbicide treatments effectively suppressed couch grass and enabled the barley crop to compete for soil N, however, both spring and autumn tillage were required for weed control. The fallow treatment impaired soil quality by reducing soil and microbial C and N, but produced similar barley yields as continuous cropping with tillage-plus-chemical control. Red clover ploughed in for green manure enhanced soil quality indicators such as soil and microbial biomass C, total and mineralizable soil N, and microbial N, but did not increase barley yield compared to continuous grain cropping.

It is possible to make ensilage of high digestibility from grass in a tower silo. The loss by drainage is negligible and can in all probability be avoided entirely.

The losses due to fermentation are not high and the final product is a highly nutritious foodstuff.

The fact that all the silage with the exception of the uppermost layer, which was not expected to be used for feeding but merely as a protective layer, has been fed and was eaten readily is proof of the ease with which grass silage of high feeding value can be made in a tower silo if adequate precautions are taken.

Ten young crossbred Finnish Landrace sheep and eleven young crossbred Damascus goats with liveweights ranging from 14 to 50 kg and of different ages and body condition, were used to develop equations to predict the body composition (chemical) in the intact body and dressed carcass of young sheep and goats. After injection with tritiated water, the animals were slaughtered and their carcasses partitioned into anatomical body components which were each analysed for chemical composition (water, fat, protein, ash) and energy content. From these components, the energy content and chemical composition of the intact bodies were calculated by summation. Apart from organ and gut fat, the two species had a similar body component composition. Goat intact bodies were more hydrated and had less fat, but were similar to sheep in protein and ash content. The energy concentration in their body components was also similar, but goats had a lower energy concentration in their intact bodies. Total body water, energy content and dressed carcass were predicted accurately by the derived equations, but fat, protein and ash were predicted with less precision.