The relationship between the selected food and rumen fermentation was investigated in Thomson's gazelle, Grant's gazelle, impala and Maasai haired sheep and goats. All animals were shot in the same grass-bushland area within 1 week during the dry season.

According to rumen contents, sheep were almost exclusively grazers. In goats, Thomson's gazelle and impala, grass accounted for about 70% of all plant parts identified. In Grant's gazelle, browse including Acacia seed constituted 68% of rumen ingesta. The two gazelle species showed a very marked preference for green grass leaves.

In sheep and goat rumens, concentrations of NH3-N and volatile fatty acids, and in vitro fermentation rates (262 and 272 μmoles gasNTPD/g D.M./h, respectively) were lowest. In the wild ruminants, concentrations of fermentation end-products were higher and the rate of fermentation significantly (P < 0·05) faster, namely 420 in Thomson's gazelle, 356 in Grant's gazelle and 376 in impala. Rumen pH was not significantly different between species, with mean values ranging between 6·3 and 6·0. Total VFA concentrations ranged between 124 and 178 m-equiv/1 in the rumen and around 25 m-equiv/1 in the abomasum. Acetic acid accounted for about 75% of the total VFAs.

It is concluded that there are large differences in the pattern of rumen fermentation between wild and domestic mixed-feeding ruminants which reflect their respective food preferences.

Three dry cows, each fitted with a permanent rumen fistula, were fed hay and flaked maize or hay and rolled barley in widely different proportions. All rations were offered at 7 kg dry matter daily for 3 weeks following hay alone. The cows refused all cereal 3 or 4 days after introduction of rations including 80 and 100% flaked maize; recovery of intake occurred in most instances within a further 3–10 days. On the 100% flaked maize ration, the refusals were associated with very low pH and high concentrations of lactic acid in the rumen.Refusalsof rolled barley were small and showed no clear pattern.

Rumen fermentation was reasonably stable during the last week of each period except with the 100% barley rations. On the rations containing flaked maize, molar proportions of volatile fatty acids (VFA) varied widely but on only one occasion did the proportion of acetic acid fall below 55% and in two cows that consumed flaked maize alone, the proportion of acetic acid in the rumen exceeded 60%. On the rations containing rolled barley, increasing proportions of barley were associated with large decreases in the proportion of acetic acid and increases in the proportion of propionic acid. The maximum proportion of n-butyric acid was found on the rations containing 50% cereal.

It is suggested that, when large proportions of cereals are fed, the proportions of VFA bear no clear relationship to the crude fibre content of the ration but that an association with rumen pH may exist.

The potential digestibility of cellulose is defined as the maximum digestibility obtainable when the conditions and duration of digestion are not limiting factors. Techniques for measuring potential cellulose digestibility were examined and the relationship between potential cellulose digestibility and in vivo cellulose digestibility was explored for a range of grasses.

Cellulose digestibility was found to reach a maximum value after 5 days incubation in vitro. No further cellulose was digested when the residues from an initial incubation for 6 days were incubated with a second rumen liquor inoculum. The values measured after a single incubation of 6 days duration were similar to cellulose digestibility coefficients measured by the suspension of ground forage samples in nylon bags in the rumen for 6 days. Plant factors appear to limit further digestion and the residue from prolonged digestion in vitro consisted only of lignified and cutinized tissue. Potential cellulose digestibility measured by either of the above techniques was higher than cellulose digestibility in vivo. The difference varied between forages and when the difference was large, the digestibility of cellulose in faeces was high.

It is suggested that measurements of the potential digestibility of cellulose in feed and faeces may be of use in estimating the digestibility of grazed herbage.

1. A field trial in which a sward, predominantly of S. 24 ryegrass was fertilized with 248, 301, 532 or 589 kg N/ha showed that a maximal yield of 13·1 tonnes/ha of artificially dried grass could be obtained from four harvests in the year.

2. The materials harvested ranged in crude protein content from 10·1 to 23·6% and in apparent digestibility of dry matter from 72 to 76%. The amounts of the grasses voluntarily consumed by sheep were slightly and significantly lower for those containing the least N × 6·25.

3. In feeding trials with twenty-five steers, a barley diet was compared with a diet entirely of dried grass from the 3rd and 4th harvests from an area in the same field which had received 487 kg N/ha. The cattle given the barley diet consumed 8·7 kg/day and gained 1·22 kg/day. Those given dried grass consumed 8·9 kg and gained only 0·85 kg/day. Carcass quality of animals given dried grass was significantly lower than of those given the barley diet.

4. Calorimetric trials were made using two herbages from the first harvest (501, 532 kg N/ha) and all four herbages from the third harvest. In each of the six experiments three sheep were each given three amounts of a herbage, and in addition were fasted. Fifty-four calorimetric observations each lasting 5 days and eighteen fasting metabolism measurements were made.

5. With both 1st and 3rd harvests, methane energy losses fell and urinary energy losses increased with the level of N fertilization. Faecal energy losses were little affected by fertilizer application and the metabolizable energy (kcal/g D.M.) was 2·8 (11·7 kJ/g) for 1st harvests and 2·6 (10·9 kJ/g) for 3rd harvests. There was a slight decline in metabolizable energy/g D.M. with N application for the 3rd harvests.

6. The net energy values of the grasses for maintenance were 1·99 kcal/g D.M. (8·4 kJ/g) for the 1st harvested material and 1·84 kcal/g D.M. (7·7kJ/g) for the 3rd harvests. Net energy values for fattening, however, were 1·28 kcal/g D.M. (5·4kJ/g) for 1st harvests and 0·87 kcal/g D.M. (3·6kJ/g) for 3rd harvests. There were no significant effects of level of N fertilization.

7. The poorer nutritive value for fattening of the 3rd harvested grass, corresponding to an efficiency of utilization of metabolizable energy of only 33%, was contrary to prediction from equations relating nutritive value to either chemical composition or to metabolizable energy. The results of the calorimetric work, however, agreed with those of the feeding trial with cattle.

8. Combination of the results of the various trials showed that it was possible to obtain 1400 kg live-weight gain/ha from a system of husbandry based on high fertilizer use and artificial drying of herbage. With a barley system a maximal output/ha would be less than half this amount.

Experiments were designed to examine differences in some morpho-physiological characters among wheat genotypes in response to drought stress at anthesis and maturity and to determine the relationships between these characters. In three sets of experiments, one set was evaluated under well-irrigated conditions and two sets under drought stress conditions by developing terminal drought stress at anthesis in one set and at maturity in the other, for 2 years. Genotypes differed in their response at both stages of plant growth for grain yield, days to heading, excised-leaf water loss, leaf membrane stability and relative water content under drought stress. Under irrigated conditions differences in the genotypes for water retention traits were not clear. There were significant genotype×environment interactions. Terminal drought stress resulted in reduced mean values and variability for all characters. The varieties WH 147 and WH 147(U) showed a combination of drought resistance, water retention and high grain yield, whereas C 306, Kharchia 65 and Hindi 62 showed a lower percentage injury in plasma membrane and better water retention in the leaves. Drought resistance index was associated with other characters.

Remote sensing (RS) offers an efficient and reliable means to map features on Earth. Crop type mapping using RS at various temporal and spatial resolutions plays an important role spanning from environmental to economical. The main objective of the current study was to evaluate the significance of optical data in a multi-temporal crop type classification-based on very high spatial resolution and high spatial resolution imagery. With this aim, three images from WorldView-3 and Sentinel-2 were acquired over Coalville (UK) between April and July 2016. Three vegetation indices (VIs); the normalized difference vegetation index, the green normalized difference vegetation index and soil adjusted vegetation index were generated using red, green and near-infrared spectral bands; then a supervised classification was performed using ground reference data collected from field surveys, Random forest (RF) and decision tree (DT) classification algorithms. Accuracy assessment was undertaken by comparing the classified output with the reference data. An overall accuracy of 91% and κ coefficient of 0·90 were estimated using the combination of RF and DT classification algorithms. Therefore, it can be concluded that integrating very high- and high-resolution imagery with different VIs can be implemented effectively to produce large-scale crop maps even with a limited temporal-dataset.

1. Teart soils contain molybdenum in amounts varying from about 0·002 to 0·010% in the surface horizon and are neutral or alkaline in reaction and often calcareous. The contents of molybdenum increase down the soil profile. Teart soils are developed from Lower Liassic materials, but all soils formed from the Lower Lias are not teart. Those which are acid in reaction in the surface horizons are not teart even if their molybdenum content is high. Others which contain little molybdenum are also not teart; such soils cover a large area in Glamorgan.

2. Molybdenum appears to be concentrated in the (uppermost) argillaceous component of the Lower Lias. The limestone contains little molybdenum. The soils of Somerset are largely derived from the upper, argillaceous component while those of Glamorgan are largely derived from the lower, limestone component. This may explain why the soils of Somerset contain much more molybdenum than those of Glamorgan.

3. Somerset soils formed from Keuper, Middle Lias, Upper Lias and Cretaceous material generally contain little molybdenum and are not teart.

4. How a knowledge of the relation between soil and teartness can be turned to practical advantage is briefly discussed.

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.

In a series of experiments in which variations in the level of carbohydrates in the plant have been brought about by means of short-term exposures to darkness and raised temperatures, it has been shown that:

1. The yield of leaf material after cutting is affected by pretreatments. This effect seems to be at least partly associated with the level of carbohydrates present in the stubble at the time of cutting.

2. The rate of growth of the plants is independent of the pretreatments imposed once growth is fully established.

1. Some preliminary observations on the carbonic anhydrase activity of the hen's oviduct are reported.

2. It is suggested that the carbonic anhydrase activity of the uterine epithelium is higher than that of the remaining oviducal tissues, and that this activity may play a part in shell secretion.

1. There was no evidence that the higher body temperature of the chick, compared with other animals, conferred any advantage on it in the digestion of high melting-point fats, as exemplified by mutton fat.

2. The digestibility of linseed oil ranged from 95·0 to 99·9%. The highest digestibility observed for mutton fat was 88·1%.

3. The capacity to digest considerable quantities of linseed oil was rapidly developed in the chick. Adaptation to digest mutton fat was much slower.

The Cornell-Penn-Miner (CPM) Dairy is an applied mathematical nutrition model that computes dairy cattle requirements and the supply of energy and nutrients based on characteristics of the animal, the environment and the physicochemical composition of the feeds under diverse production scenarios. The CPM Dairy was designed as a steady-state model to use rates of degradation of feed carbohydrate and protein and the rate of passage to estimate the extent of ruminal fermentation, microbial growth, and intestinal digestibility of carbohydrate and protein fractions in computing energy and protein post-rumen absorption, and the supply of metabolizable energy and protein to the animal. The CPM Dairy version 3.0 (CPM Dairy 3.0) includes an expanded carbohydrate fractionation scheme to facilitate the characterization of individual feeds and a sub-model to predict ruminal metabolism and intestinal absorption of long chain fatty acids. The CPM Dairy includes a non-linear optimization algorithm that allows for least-cost formulation of diets while meeting animal performance, feed availability and environmental restrictions of modern dairy cattle production. When the CPM Dairy 3.0 was evaluated with data of 228 individual lactating dairy cows containing appropriate information including observed dry matter intake, the linear regression between observed and model-predicted milk production values indicated the model was able to account for 79·8% of the variation. The concordance correlation coefficient (CCC) was high (rc=0·89) without a significant mean bias (0·52 kg/d; P=0·12). The accuracy estimated by the CCC was 0·997. The root of mean square error of prediction (MSEP) was 5·14 kg/d (0·16 of the observed mean) and 87·3% of the MSEP was due to random errors, suggesting little systematic bias in predicting milk production of high-producing dairy cattle. Based upon these evaluations, it was concluded the CPM Dairy 3.0 model adequately predicts milk production at the farm level when appropriate animal characterization, feed composition and feed intake are provided; however, further improvements are needed to account for individual animal variation.

The effects of straw incorporation (early and late cultivation) and straw burning were contrasted in a split-plot study examining the impact of long-term straw residue management, and six fertilizer nitrogen (N) rates on soil mineral nitrogen, crop fertilizer N requirements and nitrate leaching losses. The experiments ran from 1984 to 1997 on light-textured soils at ADAS Gleadthorpe (Nottinghamshire, UK) and Morley Research Centre (Norfolk, UK).

Soil incorporation of the straw residues returned an estimated 633 kg N/ha at Gleadthorpe and 429 kg N/ha at Morley on the treatment receiving 150 kg/ha per year fertilizer N since 1984. Straw disposal method had no consistent effect on grain and straw yields, crop N uptake, or optimal fertilizer N rates. In every year there was a positive response (P<0·001) to fertilizer N in straw/grain yields, N contents and crop N offtakes at both sites. Nitrate leaching losses were slightly reduced by less than 10 kg N/ha where straw residues had been incorporated, while fertilizer N additions increased nitrate leached at both sites.

At both sites there was a consistent effect (P<0·001) of straw disposal method on autumn soil mineral N, with values following the pattern burn>early incorporate>late plough. The incorporation of straw residues induced temporary N immobilization compared with the treatment where straw was burnt, while the earlier timing of tillage on the incorporate treatment resulted in slightly more mineral N compared with the later ploughed treatment. Fertilizer N rate increased (P<0·001) soil mineral nitrogen at both sites. At Morley, there was more organic carbon in the plough layer where straw had been incorporated (mean 1·09 g/100 g) rather than burnt (mean 0·89 g/100 g), and a strong positive relationship between organic carbon and fertilizer N rate (r2=93·2%, P<0·01). There was a detectable effect of fertilizer N on readily mineralizable N in the plough layer at both Gleadthorpe (P<0·001) and Morley (P<0·05). At Morley, there was a consistent trend (P=0·06) for readily mineralizable N to be higher where straw had been incorporated rather than burnt, indicating that ploughing-in residues may contribute to soil nitrogen supply over the longer term.

1. Four replicated experiments were made to determine the rate of passage of meal through the alimentary tract of pigs on different feeding treatments. In each experiment stained meal was used and the results were expressed by means of excretion curves. From these, mean retention times (R values) were calculated. All the curves were of a similar sigmoid shape.

2. A significant inverse relationship was found between the mean retention time and the total weight (meal plus water) of the ration. This relationship was found when (a) the weight of meal was constant and the weight of water was varied, (b) the weight of water was constant and the weight of meal was varied, and (c) the total combined weight of meal and water (at the same ratio) was varied.

3. The digestibility of the dry matter and crudec protein in Exps. 1–3 was not altered greatly as a result of the different feeding treatments.

4. In Exp. 4, similar rates of passage were found in pigs fed on the two rations of widely different digestibilities.

5. The dry-matter content of the faeces of the pigs was remarkably constant over a wide range of water and food intakes when using the same meal.

1. The porosity of egg is measured by the usual practice of estimating the weight loss under standard conditions. The porosity coefficient is expressed as the loss in weight in mg. per sq. cm. of egg surface per 24 hr. at 37°C.

P coeff.=mg. cm.2 24 hr. 37°.

2. It is shown that eggs of even curvature approximate closely to the ideal mathematical form of two hemi-prolate spheroids, differing in their eccentricities and meeting in the plane of their common minor axes. On this assumption the divergence between the observed and calculated long perimeter is only +0·618 per cent (five eggs) and between the observed and calculated volumes+3·78 per cent (seventy eggs).

3. It is explained how, by taking the specific gravity of the egg to correct for departures from the theoretical form, it is possible to calculate the surface area with an error not exceeding 1 per cent.

Drainage lysimeters were used to estimate actual transpiration of a perennial ryegrass sward; this is compared with the calculated values for potential transpiration. Losses to drainage of nitrate nitrogen (NO3–-N) under differing levels of application of nitrogen fertilizer were examined. When 250 kg N/ha were applied annually losses of NO3-N were negligible; when 500 kg N/ha were applied up to 142·9 kg N/ha were lost to drainage. Concentration of NO3-N in the leachate with an application of 250 kg N/ha was low (1–5 ppm); with 500 kg N/ha the concentration ranged from 10 to 109 ppm. Losses of NO3–-N were particularly severe during winter following a dry autumn. When drainage occurred during the growing season losses were minimal.

Concentrations and quantities of K, Ca, Mg, Na, P, Cl and S (as sulphate) leached wore also examined.

The effects of yeast Saccharomyces cerevisiae, either inactivated (by osmotic pressure, designated IY) or provided as a culture containing live yeast cells (YC), on ruminal fermentation of two different diets were investigated in vitro. Total mixed rations (TMR) having forage:concentrate ratios of 0·6:0·4 (medium–high forage diet) and 0·2:0·8 (low-forage diet) were incubated in batch cultures of mixed ruminal micro-organisms to which either IY (to reach concentrations of 500 and 250 mg product/l incubation medium) or YC (at a concentration of 150 mg product/l) were added directly as powder. To evaluate the effects of the additive on ruminal microbial population, sheep used as donors of rumen fluid were allocated to three experimental groups: Control (no additive), IY and YC, that received a diet with the corresponding additive for 10 days. With both diets, YC decreased ruminal pH compared to control, whereas IY had no effect. Adding yeast products to the high-fibre diet affected total volatile fatty acid (VFA) production and VFA composition, in general with a slight increase in IY and a significantly greater increase in response to the addition of YC. Ammonia nitrogen (P=0·006), total gas production (P<0·001) and in vitro dry matter disappearance (IVD) (P<0·001) showed the highest values with YC. Methane production was higher than the control when the IY inoculum was used, and increased even more with the YC inoculum (P<0·001). With the high-concentrate TMR, no effects on total VFA concentration were observed when yeast additives were used. Similar trends were shown for lactate and methane production and total gas production, where values tended to be higher when using the YC inoculum (P values of 0·055, <0·001, 0·006 and <0·001, respectively). After 144 h of incubation, differences were observed only with the high-fibre diet in the cumulative gas production at 24 h of incubation and in the average fermentation rate, which was greater with YC, although the asymptotic gas production was not affected. These results indicate that live yeasts affect ruminal fermentation slightly more than inactivated yeasts, although both products require a regular administration and some adaptation of the ruminal microbial population for the stimulatory effects to become apparent. The effects of yeasts on ruminal fermentation are diet-dependent, being more noticeable with a high-fibre substrate, and subtle with a high-concentrate diet.

1. Broad bean plants caged with bees produced more seeds per pod, more seeds per plant, heavier seeds and a greater weight of seeds per plant than plants caged without bees. They also had more mature pods at the first harvest but the total number of pods picked was about the same for cages with and without bees. The flowering season of plants caged without bees was extended.

2. Field bean plants caged with bees had more seeds per pod and more seeds per plant than plants without bees.

3. For both crops, plants in the open had about double the number of pods, beans and weight of beans as plants in cages.

The extents and sites of digestion of organic matter (OM), and its constituent watersoluble carbohydrates, organic acids, pectin, cellulose, hemicellulose and crude protein have been studied in sheep prepared with re-entrant duodenal cannulas and fed four fresh herbage diets, Ruanui perennial ryegrass, Tama Westerwolds ryegrass, Pitau white clover and Fakir sainfoin, at each of two levels of intake.

The water-soluble carbohydrate, organic acids and pectin of all diets were almost completely digested within the rumen. Some 10% of water soluble carbohydrate reached the duodenum on each diet, though this may not have been of dietary origin. Only on legume diets, where pectin concentration was higher, did measurable amounts of pectin reach the intestine, accounting for some 5% of the pectin.

Hemicellulose and cellulose digestibilities differed between diets, being lowest for sainfoin, and next lowest for clover. Between 79 and 94% of digestible hemicellulose was digested in the stomach, but diet and intake had no significant effect on this partition. Of the digestible cellulose, 87–97% was digested in the stomach.

Digestibility of N was lowest for sainfoin and highest for Tama ryegrass. There were no significant differences between herbage species or intake in the percentage of digested N digested in the stomach or intestines. The tannin contained in sainfoin had no effect on nitrogen digestion.

Data from this and other studies reported in the literature were examined as a basis for establishing prediction equations whereby the partition of digestion of the major carbohydrate and nitrogenous constituents in stomach and intestines might be estimated from data obtainable from standard digestibility trials. Regressions were developed for predicting the amounts of OM, cellulose, and hemicellulose digested in the stomach. There are not yet enough suitable data available to predict the amount of nitrogen entering the small intestine.

A field experiment is described in which three rates of pig and cow slurry were applied to a ryegrass sward over a period of 16 years. The experiment included control plots and plots receiving fertilizer supplying 200 kg N, 32 kg P and 160 kg K/ha per year.

The slurry nutrient concentrations were similar to published values. Pig slurry was more variable than cow slurry and both varied significantly from year to year. Slurry was applied at 50, 100 or 200 m3/ha per year, with each rate divided into three equal applications.

Even the highest slurry application rate did not depress herbage yield, which showed a typical response curve to the amount of soluble nitrogen applied. The ammoniumnitrogen content of slurry (61% on average) gave an adequate measure of its effect on herbage yield when it was applied three times per year in spring and summer.

Recovery of phosphorus in the herbage averaged 30% from pig slurry, 40% from cow slurry and 66% from-fertilizer. Pig slurry supplied more phosphorus than did cow slurry, and herbage phosphorus content was significantly correlated with the amount applied. Much of the slurry phosphorus may have been organically bound and not available to plants in the short term.

Recovery of potassium from pig slurry and fertilizer was nearly 90% and from cow slurry about 70%. Cow slurry supplied potassium in excess of crop requirements so that it accumulated in the soil under the largest dressing. Soil phosphorus reserves declined under the smallest dressing of cow slurry but were maintained at higher application rates. The pig slurry produced a marked accumulation of phosphorus under the largest dressing. The substantial accumulations of phosphorus and potassium from pig and cow slurry respectively gave marked penetration of the soil below 10 cm depth only at the highest application rate. The data suggest that at rates typical of farm practice significant losses of phosphorus and potassium from the rooting zone would be unlikely to occur.

The main invading plant species were Agrostis stolonifera L. and Poa spp. Small slurry dressings produced a similar botanical composition to that of plots given fertilizer. Increasing slurry application rates decreased the proportion of L. perenne and increased that of A. stolonifera but only under the largest dressing did L. perenne fall to a small proportion of the sward and A. stolonifera become very dominant. L. perenne made maximum contribution to herbage dry-matter yield early in the season while the proportion of A. stolonifera increased as the season progressed.

Under these conditions even extremely large slurry dressings did not depress herbage yield and may not necessarily have reduced herbage quality despite marked changes in sward botanical composition.