A feeding and balance trial was conducted for 15 weeks on 25 lambs (aged 3–5 months) divided into five groups of 5 animals each on a basal ration consisting of oats, groundnut cake, barley, common salt, green grass and wheat straw. The five groups were fed a mineral supplement as follows:

Group I. Basal ration plus ‘Supermindiff’ mineral mixture (control group).

Group II. Basal ration plus calcined superphosphate.

Group III. Basal ration plus superphosphate.

Group IV. Basal ration plus superphosphate plus oral cobalt chloride (3 mg Co/10 kg body weight).

Group V. Basal ration plus superphosphate plus parenteral vitamin B12 (50 μg/week/ animal).

Calcination of fertilizer-grade superphosphate at 600°C for 2 h reduced the fluorine content from 23350ppm to 1600 ppm. The results show that high fluorine or superphosphate significantly reduced growth rate and retention of calcium and phosphorus and significantly increased blood inorganic phosphorus. Calcination of superphosphate in Group II gave comparable results to the control group (Group I). The oral Co or parenteral vitamin B12 supplementation (Groups IV and V) did not ameliorate the adverse effects of high fluorine in superphosphate.

It is concluded that calcination of superphosphate at 600°C for 2 h yields a suitable defluorinated product which can be used as a phosphorus supplement in the feeding of animals. Fertilizer-grade superphosphate is unsuitable due to its high fluorine content, the adverse effects of which are not mitigated by oral Co or parenteral vitamin B12 supplementation.

Multiparous Corriedale ewes were maintained on a constant feed intake such that the body weight (i.e. live weight less gravid uterus) of single-bearing ewes at the end of gestation approximated their live weight at mating. The ewes were allocated to one of five groups, designated for slaughter at 0, 50, 90, 120 and 140 days of gestation. At slaughter, the gravid uterus was removed, weighed and its components dissected out and the contents of all sections of the gastro-intestinal tract were removed, weighed and sampled.

Foetal growth was described by a Gompertz model. It was predicted that, at day 150, a twin foetus would have been 0·95 of the weight of a single foetus but this difference was not statistically significant. The foetal proportion of the gravid uterus followed a sigmoid curve during gestation to reach a predicted value of 0·60 at day 150. Predicted birth weights represented 10·4 and 18·6% of maternal body weight in single- and twin-bearing ewes.

The digesta content of the rumen and of the whole gastro-intestinal tract was not significantly affected by gestation. However, there was a tendency for the values to decline to day 90, then increase during the last third of gestation. It was suggested that the decline was due to hormonal rather than direct physical effects. By contrast, the amounts of organic digesta constituents in the rumen descreased as gestation progressed (P < 0·01) indicating an effect of gestation on rumen propulsive activity.

Forty-eight sows were partially hysterectomized on day 10 (day 0 = 1st day of oestrus) of the oestrous cycle such that the isolated-contralateral ovary received either an ovarian or an ovarian and uterine blood supply. These two treatments were examined for their ability to affect corpora lutea (CL) function when 10, 20, 40 and 80 cm (12 sows/group) of the ipsilateral uterine horn remained intact. Sows with only 10 cm of uterine tissue failed to return to oestrus when observed until day 40. When 80 cm of uterine tissue remained, all the sows recycled between days 20 and 24. As the length of uterine horn increased from 10 to 80 cm the contralateral ovary became susceptible to luteolysis. At these lengths (20–40 cm), increased blood supply to the contralateral ovary afforded the luteal cells resistance to luteolysis (uterine length × blood supply interaction, P < 0·05). An additional four sows received 125I-labelled microspheres for purposes of determining CL blood flow following these alterations of blood supply to the isolated ovary. Blood flow to the CL was increased in three of the four sows when the isolated ovary received an additional uterine blood supply. Results from these experiments support the concept of an involvement of blood flow in the regulation of CL function.

Swards on wet hill land in mid-Wales, which had been converted from semi-natural rough grazing (dominated by Molinia caerulea, Nardus stricta or Calluna vulgaris) by surface-sowing in the period 1965–75, were examined in 1982, 1984 and 1996/97, using a point quadrat technique, in order to record the extent to which the sown species had persisted and the ingress of unsown species.

Lolium perenne had persisted to 1996/97 to the extent of being 20% of the sward on sites c. 300 m above sea level and 3% on sites at c. 500 m. Trifolium repens had persisted to c. 7% of the sward at both elevations. Festuca rubra was 6% of the sward on the higher sites and close to zero on the lower ones. The other main sown species, Phleum pratense, was present in only trace amounts on all sites in 1982, 1984 and 1996/97. The failure of T. repens to persist in larger amounts was attributed in part to below optimum soil pH and K and to the annual application of fertilizer N. The decline in L. perenne was attributed in part to severe winters on the higher sites and to below optimum soil K and pH. Agrostis spp. were the most prominent of the unsown species. Poa spp. appeared to stabilize at 8–15% of the sward. Stellaria media and Holcus lanatus became fairly prominent on the lower sites and Anthoxanthum odoratum on the higher sites. A supplementary study of the lower sites showed that the lime had been effective to at least the 20–25 cm layer of soil, that the distribution of plant roots in the soil was not abnormal, that T. repens plants had a satisfactory number of root nodules and that the soil contained a satisfactory number of earthworms.

1. Studies lead to the conclusion that Chibnall-preparations of pasturage proteins, in spite of their small amounts of carbohydrate impurity, may yet yield, on hydrolysis by mineral acids, practically the right amounts even of most of those amino-acids which are adversely affected by carbohydrates to some extent when tested singly under the conditions.

2. Preparations made in another way after treating the pasturage with ether as in the original Chibnall-method showed features of interest in the problem of attaining very pure proteins now much needed for purposes of comparison.

3. A new method is introduced by which it is possible to compare what may be extracted from the protoplasm of fresh unpulverized pasturages with the composition of the natural saps on a unit weight basis.

4. Production and breakdown of protoplasmic protein in perennial rye-grass during growth consistently appeared related to variations in the content of “nitrogen” and phosphates in the saps and the supplies of “nitrogen” and phosphates from the soil.

Quantitative and qualitative bacteriological comparisons were made between complementary samples of cud and rumen contents using five fistulated cows receiving various diets; no marked differences were observed between samples taken from the same animal at the same time. This, with the method of collecting cud described, simplifies bacteriological evaluation of the rumen contents of intactanimals.

That rhizobial strains belonging to pulses not only differ among themselves but also show differences in their effectiveness when Azotobacter isolates are used as co-inoculants has been shown by Sanoria & Ram (1979) and Sanoria & Mallik (1981). This has now been further demonstrated in trials conducted over 2 years using bengal gram. These trials also included a phosphate solubilizing bacterium (Pseudomonas spp.) as an extra inoculant but it had no effect on the responses obtained.

The personality of an animal is described by traits that cause consistent actions and reactions to environmental stimuli. An important part of personality is the reaction to unpleasant or uncontrollable situations. Methods described in the literature to measure personality in animals are often based on measuring or rating escape behaviour in these situations. In the methods described, human handlers are frequently part of the experiment or the animals’ personalities are scored by humans. Thus, these methods are at least partly subjective.

In the current study, an appliance to measure objectively the escape behaviour of ungulates and their reluctance during an uncontrollable situation (restraint) with a rather simple and comprehensible methodology is presented using a force transducer with adequate peripheral equipment. While the animals were restrained, a tractive force-time diagram describing escape behaviour was recorded and later analysed with software developed specifically.

To evaluate this newly developed technical method, 24 three-month-old calves were restrained by being tethered for 30 min on a halter that was connected to the force transducer. From the tractive force-time diagram, tractive force, maximal tractive force and the number of pulls that the calves performed during 5-min intervals were calculated. The multivariate results were analysed with a k-means-algorithm (function ‘kcca’) and a hierarchical clustering (function ‘hclust’) included in R version 2.12.1.

Both analyses revealed two clearly separated clusters including the same individuals in each analysis. The animals of cluster 1 showed a continuously higher reaction level than those of cluster 2 with a strong reaction in the beginning, a short decrease before increasing during the middle of the experiment and a final decrease at the end of the test. The animals of cluster 2 had a lower and quite steady reaction level throughout the experiment, although even here a slight increase during the middle of the experiment could be detected before a final decrease towards the end of the test was shown. There was no significant difference in weight between the two clusters.

The results showed that this newly developed method was able to detect differences in the animals’ escape behaviour patterns and reluctance with the measured parameters.

Field experiments were conducted during the two monsoon seasons of 1985 and 1986 at Kharagpur, West Bengal, to investigate the effect of pigeonpea cultivars and their planting pattern on the performance of a groundnut–pigeonpea intercrop. In intercropping the crops were also sown at 100% population of their sole crops. Groundnut plant growth and development was affected by intercropping with pigeonpea and the decline in pod yield ranged from 7 to 50% of the sole crop yield. The compact, short-statured and short duration pigeonpea cultivar, ICPL87, intercepted only 50% of the incoming solar radiation as against the 70% intercepted by LRG30 at the peak vegetative stage. The significantly higher groundnut yield (48%) obtained from the intercrop with the former pigeonpea cultivar as compared to the latter justifies the belief that the performance of the groundnut was light-related. This was further confirmed when the light interception by pigeonpea was reduced by increasing the row spacing from 90 to 150 cm and there was a consequent increase in groundnut yield. The cultivar and row arrangement of pigeonpea that allowed equal utilization of light by both crops gave increased productivity.

The effect of seedling disturbance on the yield and growth habit of swedes was studied in ten experiments during the period 1960–3. Seedling disturbance consisted of the removal of soil from around the seedlings during singling, thus exposing the hypocotyl and leaving the seedlings prostrate.

Plant numbers were reduced slightly by seedling disturbance in half the experiments but not sufficiently to be a source of yield loss at the populations attained.

Seedling disturbance greatly increased the incidence of prostrate growth in swede varieties of intermediate shape, such as Victory. Two globe-shaped varieties, Bangholm and Pentland Harvester, grew erect irrespective of singling technique.

Disturbance of seedlings reduced yield when it increased the number of prostrategrowing plants. The yield depression ranged from 0·2 to 5·2 cwt D.M./acre.

1. Experiments in which were measured the resistances to (a) transverse breaking, (b) crushing, and (c) parting under tensile pull of standard blocks of soil prepared in different ways and under particular moisture conditions are described and discussed.

2. The soils examined comprised three highly colloidal siliceous soils containing amounts of calcium carbonate ranging from 7·2 to 0·2 percent., and two red lateritic soils.

3. The most significant results were obtained by employing, in a special tenacity apparatus, granular test-blocks, prepared by moistening sieve-graded dry soil packed into rectangular moulds. The results thus obtained are believed to furnish a reliable measure of the cohesiveness of soil colloidal matter, especially in soil blocks that have previously been brought to constant moisture content in a humidifier. The method of preparation simulates the effect of rain in causing the “running together” of colloidal soil particles.

4. The relative cohesiveness of the soils examined appears to follow the same order as their rates of settling from aqueous suspension. This observation strengthens the view that cohesiveness in colloidal soils is to a certain extent due to chemical forces that depend on the presence of active atoms or atomic groups possessing powerful fields of residual affinity, although probably film tension also plays a part.

This paper reports genetic differences between 20 Mashona bulls from smallholder farms, 14 from Makoholi Research Station, three from commercial farms and two reference sires, in Zimbabwe. An animal model, fitted through the derivative free Restricted Maximum Likelihood program (DFREML), was used to analyse 707 birth weight and 623 weaning weight records. Both the mean breeding values of the reference sires and the ranch bulls were significantly (P < 0·05) higher than the mean breeding values of smallholder bulls for birth weight (by 1·6 and 1·7 kg, respectively) and weaning weight (by 10·4 and 11·0 kg, respectively). However, seven of the 20 bulls from smallholder farms were among the top 45% of bulls with high breeding values for both birth and weaning weight. The mean breeding value of bulls from Makoholi was not different from any of the other groups, for all traits studied. It was proposed that future efforts to form nucleus herds to improve the weaning weights of indigenous cattle should include the genetic pool in smallholder farms.

Honeybee foraging can transfer exogenous genes from genetically modified (GM) oilseed rape (Brassica napus L.) to closely related plants, which not only induces potential ecological risks but also contaminates non-GM seeds or honey products with GM ingredients. These events may lead to international trade disputes. Chinese honeybees (Apis cerana cerana Fabricius) and a herbicide (glufosinate)-resistant GM strain of B. napus (Z7B10) were studied to examine the effects of honeybee short-range foraging on oilseed rape gene flow and honey ingredients. Results showed variable frequencies of gene flow between GM and non-GM oilseed rape cultivars, with the highest frequency under nylon net isolation with artificially stocked honeybees, the lowest frequency under nylon net isolation alone, and an intermediate frequency under natural pollination, suggesting the important role of honeybee foraging in gene flow frequency. Additionally, GM pollen grains were found in honey collected from honeybees foraging on both GM and non-GM oilseed rape cultivars. The phosphinothricin acetyltransferase protein was also detected in both unbroken pollen-containing and pollen-free honey by protein testing strips, suggesting that honeybee foraging on GM oilseed rape could lead to contamination with GM ingredients. Overall, the results provide a direct scientific basis for the ecological risk assessment and safety management of GM oilseed rape.

Moisture movement through soil under trickle irrigation was studied in the laboratory at the Central Soil Salinity Research Institute, West Bengal, in 1988/89. Using a cylindrical flow model, the finite difference technique was used to compute the 2-dimensional moisture distributions and wetting front advancements in soils with clay contents ranging from 22·1 to 51·8%. Seven-day cyclic irrigations, each day having one on-cycle (infiltration) with a constant trickle discharge of 0·3 litre/h for 12 h and one off-cycle (redistribution) for 12 h, were used with two water qualities, EC 0·15 and 0·64 S/m. Moisture distributions were measured in artificially packed soil columns 60 cm high and 56 cm in diameter. The degree of agreement between the theoretical and observed values was expressed by Relative Error Percent (REP), defined as the difference between the two, divided by the observed value and expressed as a percentage. The mean REP ranged from 0 to 30, 62·5% of the values falling in the range 0–10, 22·5% from 10 to 20, and 15% from 20 to 30, irrespective of soil texture, water salinity or the irrigation cycle used. It was concluded that the theoretical data closely matched the experimental results. The wetting front in the soil columns was defined as the minimum detectable increase in moisture (10-3 cc/cc) from the initial content, and its advancement was calculated over the entire period of on-off cycles. This model was also used to calculate, for one soil, the theoretical moisture distribution under trickle irrigation with simultaneous loss by evaporation, which is an essential component of field moisture balance.

The effects of food ingestion on the total energy exchange of man and of the dog have been fairly completely worked out. Lavoisier was the first to show that the oxygen absorption and carbon dioxide production were increased by ingestion of food. Rubner, in addition to confirming these observations of Lavoisier, showed that the heat given off from the body after food was equal to the heat evolved from the foodstuffs actually oxidised within the body and thus established the agreement between direct and indirect calorimetry. He showed, further, that the increase in heat production was greatest after protein food. This specific effect of protein food he designated the “specific dynamic action.” The work of Rubner has been continued by, amongst others, Magnus-Levy, Benedict, and Lusk. The latter showed that the specific dynamic action of proteins is due to the special stimulating effect of certain amino-acids on the tissues and that the increased heat production after fat and carbohydrate ingestion is due to plethora of oxidisable molecules round the living body cells. Recently Wood and his school (1) have carried out investigations on the metabolism after food in pigs.

In investigations on the effects of calcium carbonate and magnesium carbonate on nitrogen fixation by A. chroococcum in soils and in solutions, the following results have been obtained:

1. Calcium carbonate in mannite solution cultures acts only as a stimulant, never as a toxic agent at least up to and including a concentration of 2%.

2. Magnesium carbonate is sharply toxic in solution cultures in concentrations in excess of ·1% to ·2%.

3. Calcium carbonate in soil cultures is without effect up to 1·4% of the dry weight of the soil when it becomes slightly toxic in the Anaheim sandy soil.

The application of 2,4-D in combination with certain mineral nutrients was shown to produce a wide range of results on yield of the potato crop. Several variables were studied for their effects on the response of the crop to a commercially available compound of the above constituents (NCL).

While no environmental factors were shown to influence the response of the crop to NCL, the following factors did: time of application, potato variety, time of harvest, plant population and the presence or absence of the parent tuber. NCL was shown to modify the growth pattern of the crop and to increase the efficiency of the leaf canopy.

A mechanistic model (COWPOLL) was used to estimate enteric methane (CH4) emissions from beef production systems in Chile. The results expressed as a proportion of gross energy intake (GEI) were compared with enteric fermentation data reported in the last Chilean greenhouse gases inventory, which utilized an earlier the Intergovernmental Panel on Climate Change Tier 2 approach. The simulation analysis was based on information from feedstuffs, dry matter intake (DMI), body weight (BW) and average daily gain (ADG) of steers raised and finished at two research facilities located in Central and Southern Chile, as well as three simulated scenarios for grass-based finishing systems in Southern Chile. Data for feedlot production systems in the central region were assessed by considering steers fed a forage : concentrate ratio of 23 : 77 using maize silage and wheat straw as roughage sources during the stages of backgrounding and fattening. Average DMI were 7·3±0·62 and 9·2±0·55 kg/day per steer for backgrounding and fattening, respectively, whereas ADG were 1·1±0·22 and 1·3±0·37 kg/day for backgrounding and fattening. For the Southern Chilean fattening production systems, the forage : concentrate ratio was 56 : 44 with ryegrass pasture as the sole forage source. In this case, average DMI was 9·97±0·51 and ADG was 1·1±0·24 kg/day per steer. Two of the grass-based scenarios used the same initial BW information as that used for the Central and Southern Chilean systems, but feedlot diets were replaced by ryegrass pasture. The third grass-based scenario used an initial BW of 390 kg. In all the grass-based scenarios an ADG of 0·90 kg/day, with maximum DMI estimated as a proportion of BW (0·01 of NDF, kg/kg BW), was assumed. The results of the simulation analysis showed that emission factors (Ym; fraction of GEI) ranged from 0·062 to 0·079 of GEI. Smaller values were associated with finishing systems that included a lower proportion of forage in the diet due to higher propionate production, which serves as a sink for hydrogen in the rumen. Cattle finished in feedlot systems had an average of 0·062 of GEI lost as CH4, whereas grass-based cattle had losses of 0·079 of GEI. Enteric CH4 emissions for the systems using grass-based and concentrate diets were 261 and 159 g/kg weight gain, respectively. The Chilean CH4 inventory employs a fixed Ym of 0·060 to estimate enteric fermentation for all cattle. This value is lower than the average Ym obtained in the current simulation analysis (0·071 of GEI), which results in underestimation of enteric CH4 emissions from beef cattle. However, these results need to be checked against field measurements of CH4 emissions. Implementation of mechanistic models in the preparation of national greenhouse gas inventories is feasible if appropriate information is provided, allowing dietary characteristics and regional particularities to be taken into consideration.