Near-infrared reflectance spectroscopy (NIRS) was used for the analysis of soil samples for silt, sand, clay, calcium (Ca), potassium (K), sodium (Na), magnesium (Mg), copper (Cu) and iron (Fe). A total of 332 samples of different soils from Uruguay (South America) were used. The samples were scanned in a NIRS 6500 (NIRSystems, Silver Spring, MD, USA) in reflectance. Cross validation was applied to avoid overfitting of the models. The coefficient of determination in calibration (R^2_{\rm cal}) and the standard errors in cross validation (SECV) were 0·80 (SECV: 6·8), 0·84 (SECV: 6·0), 0·90 (SECV: 3·6) in per cent for sand, silt and clay respectively. For both macro and microelements the R^2_{\rm cal} and SECV were 0·80 (SECV: 0·1), 0·95 (SECV: 2·9), 0·90 (SECV 0·8), for K, Ca, Mg in g/kg respectively, and 0·86 (SECV: 0·82) and 0·92 (SECV: 25·5) for Cu and Fe in mg/kg. It was concluded that NIRS has a great potential as an analytical method for soil routine analysis due to the speed and low cost of analysis.

A collection of 112 accessions of common beans from the north of Spain has been evaluated for 24 characters during 2 years. A combination of cluster plus canonical discriminant analysis using morphological traits to generate canonical functions was able to separate landraces from different geographic areas of northern Spain, assigning them to germplasm groups related to their centres of origin. The accessions were clustered in three groups in both years. Two groups were related to races with South American origins (races ‘Chile’, ‘Peru’ and ‘Nueva Granada’), the other group was related to races with Mesoamerican origins (races ‘Mesoamerica’ and ‘Durango’). The variation found was higher in the west of the geographic area studied decreasing toward the east. These results will permit a more efficient management and conservation of these resources, and their efficient use in breeding programmes.

This study was conducted to determine the effects of plastic film mulch on percentage of abortive tillers and harvest index (HI) in two spring wheat populations, and to explore its mechanism in relation to size inequality and life-history strategies theory. Field-grown spring wheat mulched with plastic film shows a remarkable increase in grain yield (an average increase of 38·5% over non-mulched control), which mainly results from the significant increase in above-ground biomass (+44·7%). At the same time, however, reproductive allocation (spike weight/above-ground biomass, −5·2%) and harvest index (−4·5%) were significantly lower (P<0·05) in mulched than unmulched populations in both of the two cultivars used. Meanwhile, the number and weight of barren shoots and the ratio of barren shoot biomass to total shoot biomass were significantly greater in mulched populations than unmulched controls both at booting, flowering and ripening stages. From tillering to ripening stages, the tendency of G (Gini coefficient) shows obvious differences between mulched populations (‘∧’ type with the peak of G at booting stages) and non-mulched controls (‘∨’ type with the lowest G at flowering and rebounded at ripening stage). At booting and flowering, the G was significantly higher in mulched populations than unmulched controls, and it was just contrary at ripening. Reproductive allocation and HI were both negatively correlated to average G of the populations, which indicated that resource use efficiency of a crop is inversely related to plant-to-plant variability and also provided further evidence for the views that stand uniformity of field crops is an important aspect of high yield formation. From these results, it was concluded that appreciable growth redundancy occurred in spring wheat populations mulched with plastic film, which may result from the exacerbated inter-plant competition and self-thinning (evidenced by the increased degree of Gini coefficient at booting and flowering stages). Thus, spring wheat cultivation with plastic film mulching does not always mean efficiency, although there is a remarkable increase in grain yields.

The effects of green manuring with dhaincha (Sesbania aculeata) and sunhemp (Crotalaria juncea) in combination with four levels of urea-N (0, 75, 150 and 225 kg N/ha) on the productivity of a subsequent sugarcane (Saccharum officinarum) crop and the fertility of the soil were examined. C. juncea contributed more nitrogen to the soils when ploughed down than S. aculeata (56·7 v. 40·0 kg N/ha). The green manures and the supplemented urea-N increased cane yield by 2 to 26% and 26 to 57%, respectively. The organic matter, total N, available P and S of the soil was only slightly increased by the incorporation of green manures.

Faecal indices were evaluated to assess organic matter digestibility (OMD) for small ruminants fed with Digitaria decumbens. A continuous digestibility trial was conducted with five Creole bucks and five Black-belly rams, fed with fresh cut Digitaria decumbens from 15 to 70 days of re-growth. The amount of herbage offered, the refusals and the faeces were weighed daily for each animal during 55 days. Herbage and faeces samples were kept to determine dry and organic matter (DM and OM), crude protein (CP), neutral and acid detergent fibre (NDF and ADF) and lignin contents (ADL). OMD was calculated per week and per animal. Predictive regressions of OMD were calculated for each species, from all the faecal components measured (CPf, NDFf, ADFf and ADLf), using linear or curvilinear models. Regressions from CPf had the lowest residual standard error (<0·028) when calculated for each species, compared with regressions from the other faecal components. Among the regressions from CPf, the lowest standard error of the predictive parameters was obtained with a model in the form of a-b/CPf, for each species. The latter allows prediction of OMD at pasture, consistent with theoretical energy requirement for both goats and ewes grazing a Digitaria decumbens based sward.

Alley cropping is a prototype agro-forestry system practiced in many parts of the humid tropics. It is one of the established, promising and sustainable low-input soil management ventures. An improved understanding of the eco-physiological relationships between the arable and perennials in this system could contribute to solving issues of sustainability for nutrient use and system productivity. Field experiments were conducted in Alabata and Ajibode, located in the derived savannah zone of Nigeria, to evaluate the comparative effects of an alley cropping system, arbuscular mycorrhizal fungi inoculation and cassava intercropping on maize yield. These on-farms trials (research managed and farmer managed) were conducted in the 1993/94 and 1995/96 growing seasons, in Rhodic Kandiustalf soil type with low nutrients. Each trial was a split-plot factorial arranged in randomized complete blocks with three replications. Biomass productions of maize and cassava tuber yield were determined. The results obtained at Alabata indicated that the maize plants were heavily infected with AM fungi whether inoculated or not. The hedgerow trees did not have a significant effect on maize yield. The increase in yield brought about by the alley cropping system was generally less than 15%, except in one farm where increases of 34·6 and 46·5% were recorded in AM-inoculated and non-inoculated plots respectively. The introduced AM fungi did not significantly enhance maize yield at Alabata; the percentage increase was not more than 24%. This trend was also observed at Ajibode. Cassava tuber yield was found to be suppressed by the alley cropping system irrespective of the cultivar. The decrease in yield ranged from 2·6 to 150·8%. However, inoculation of the cassava with exotic AM fungi brought about an enhancement of its tuber production. The increase ranged from 20·7 to 189·8% depending on the treatment combination. It is therefore necessary to encourage adoption of the improved alley cropping system integrated with mycorrhizal technology.

The yield stability of intercropping systems is important in developing cropping systems that produce economic yields over a wide range of environments. Field studies were conducted during the 1997/98 and 1998/99 growing seasons at three locations in the forest and forest–savannah transition zones of Ghana to determine yield, land use efficiency and yield stability of cassava (Manihot esculenta), maize (Zea mays), soya bean (Glycine max) and cowpea (Vigna unguiculata) intercrop systems. The cropping systems consisted of a factorial combination of two cassava varieties: ‘Gblemoduade’ (an improved, highly branched variety) and ‘Ankra’ (a local variety with fewer branches) and three spatial arrangements. Cowpea rows were planted in the minor season into cassava as a successive crop to maize and soya bean after their harvest in the major season. Intercropping significantly reduced grain or tuber yield of maize, cassava ‘Gblemoduade’ and cassava ‘Ankra’ by 23–70%, 16–49% and 24–64%, respectively. Maize yield decreased with increased number of soya bean rows. ‘Gblemoduade’ outyielded ‘Ankra’ by more than 100% under both intercrop and sole crop. The yield of soya bean increased with increased number of soya bean rows, but did not differ in response to the cassava variety. However, cowpea yield was higher when intercropped with ‘Ankra’ than with ‘Gblemoduade’. The intercrops had higher land use ratios (LER=1·27–2·83) and were more stable than the sole crops. Intercrops involving ‘Ankra’ had higher LER (2·14–2·18) than systems with ‘Gblemoduade’ (LER=1·83–1·99), but their yield stabilities were similar.

An indoor experiment involving 10 rumen-cannulated Romney sheep was conducted in May and June 1998 at AgResearch Grasslands, Palmerston North, New Zealand, under restricted feeding conditions, in order to test the hypothesis that animal factors, in particular rumen fractional outflow rate (FOR) and rumen volume, have an influence on the between-sheep variation in methane (CH4) emission. Sheep were fed 2-hourly on chaffed lucerne hay. Following an acclimatization period of 21 days, the experiment lasted 16 days. Energy and nitrogen (N) balances were measured on days 1–6. Cr-EDTA marker was continuously infused into the rumen from day 9 to 16, and rumen contents emptied and sampled on days 13 and 16. Particulate and fluid FOR were estimated using feed lignin and Cr-EDTA, respectively. Daily CH4 production was measured by the sulphur hexafluoride tracer technique on days 2, 5, 6, 12 and 15 of the experiment.

CH4 production (g/day) was positively correlated with the pool size of organic matter (OM) in the rumen (OM pool, g) (r=0·84, P=0·002), OM intake (OMI, g/day) (r=0·67, P=0·04), and the rumen fill (g, wet digesta) (r=0·76, P=0·01). Multiple regression analysis showed that CH4 production was best predicted (R2=0·88) as a function of OM pool and the molar % of butyrate; however, OM pool alone accounted for a large proportion (R2=0·71) of the variation in CH4 production.

CH4 yield (% gross energy intake, % GEI) was negatively correlated with the particulate FOR (%/h) (r=−0·75, P=0·01) and buffering capacity of rumen fluid (mmol HCl) (r=−0·72, P=0·02), but positively correlated with the digestibility of cellulose (r=0·66, P=0·04). Multiple regression analysis showed that CH4 yield was best predicted as a function of particulate FOR, OMI (g/kg liveweight0·75) and the molar % of butyrate (R2=0·88). Particulate FOR alone explained a large proportion (R2=0·57) of the variation in CH4 yield. Particulate FOR was negatively correlated with rumen fill (r=−0·69, P=0·03) and digestibility of cellulose (r=−0·65, P=0·04).

These results suggest that sheep with lower rumen particulate FOR (i.e. longer rumen retention times) had larger rumen fills and higher fibre digestibilities and CH4 yields. If rumen particulate FOR is to be used as a tool for CH4 mitigation, the repeatability of its relationship to CH4 emission must be assessed, preferably under grazing conditions.

Data from six studies with male broilers fed diets covering a wide range of energy and protein were used in the current two analyses. In the first analysis, five models, specifically re-parameterized for analysing energy balance data, were evaluated for their ability to determine metabolizable energy intake at maintenance and efficiency of utilization of metabolizable energy intake for producing gain. In addition to the straight line, two types of functional form were used. They were forms describing (i) diminishing returns behaviour (monomolecular and rectangular hyperbola) and (ii) sigmoidal behaviour with a fixed point of inflection (Gompertz and logistic). These models determined metabolizable energy requirement for maintenance to be in the range 437–573 kJ/kg of body weight/day depending on the model. The values determined for average net energy requirement for body weight gain varied from 7·9 to 11·2 kJ/g of body weight. These values show good agreement with previous studies. In the second analysis, three types of function were assessed as candidates for describing the relationship between body weight and cumulative metabolizable energy intake. The functions used were: (a) monomolecular (diminishing returns behaviour), (b) Gompertz (smooth sigmoidal behaviour with a fixed point of inflection) and (c) Lopez, France and Richards (diminishing returns and sigmoidal behaviour with a variable point of inflection). The results of this analysis demonstrated that equations capable of mimicking the law of diminishing returns describe accurately the relationship between body weight and cumulative metabolizable energy intake in broilers.

Lentil (Lens culinaris Medik.) cultivars (Jordan 1 and Jordan 2) were sensitized to chlorsulfuron herbicide. Both cultivars were subjected to three doses of gamma-irradiation (90, 100 and 110 Gray) to develop plants tolerant/resistant to this herbicide. The herbicide-tolerant plants as well as the sensitized plants were subjected to acetolactate synthase (ALS) enzyme assay to reveal the biochemical basis of plant tolerance. The results indicated that as the radiation dose increased, the tolerance to the herbicide application decreased in both lentil cultivars. Cultivar Jordan 1 showed sensitivity to chlorsulfuron herbicide at all treatments compared with that of Jordan 2. ALS enzyme activity in the two lentil cultivars was inhibited by chlorsulfuron. The irradiated plants (90 Gray) in both treated seeds plants (M1) and seeds of tolerant plants (M2) showed a lower level of inhibition to high concentration (250 μg/l) of chlorsulfuron herbicide. The results suggested an alteration of the expression system of ALS gene(s) leading to overproduction of altered ALS enzyme at the herbicide binding site of the enzyme in lentil plant.

Based on the knowledge that alpaca (Lama pacos) have a lower fractional outflow rate of feed particles (particulate FOR) from their forestomach than sheep (San Martin 1987), the current study measured methane (CH4) production and other digestion parameters in these species in three successive experiments (1, 2 and 3): Experiment 1, lucerne hay fed indoors; Experiment 2, grazed on perennial ryegrass/white clover pasture (PRG/WC); and Experiment 3, grazed on birdsfoot trefoil (Lotus corniculatus) pasture (Lotus). Six male alpaca and six castrated Romney sheep were simultaneously and successively fed on the forages either ad libitum or at generous herbage allowances (grazing). CH4 production (g/day) (using the sulphur hexafluoride tracer technique), voluntary feed intake (VFI), diet quality, and protozoa counts and volatile fatty acid concentrations in samples of forestomach contents were determined. In addition, feed digestibility, energy and nitrogen (N) balances and microbial N supply from the forestomach (using purine derivatives excretion) were measured in Experiment 1.

Diets selected by alpaca were of lower quality than those selected by sheep, and the voluntary gross energy intakes (GEI, MJ) per kg of liveweight0·75 were consistently lower (P<0·001) for the alpaca than for the sheep (0·74 v. 1·36, 0·61 v. 1·32 and 0·77 v. 2·53 on lucerne hay, PRG/WC and Lotus, respectively). Alpaca and sheep did not differ (P>0·05) in their CH4 yields (% GEI) when fed on lucerne hay (5·1 v. 4·7), but alpaca had a higher CH4 yield when fed on PRG/WC (9·4 v. 7·5, P<0·05) and Lotus (6·4 v. 2·7, P<0·001). When grazing on Lotus, the sheep had very high protozoa counts in their forestomach contents, compared with those with the other forages and those in the alpaca. On lucerne hay and Lotus, but not on PRG/WC, the alpaca had higher (P<0·01) acetate/propionate ratio in their forestomach fluid than sheep. When fed on lucerne hay, alpaca and sheep did not differ (P>0·05) in diet N partition or microbial N yield, but alpaca had higher (P<0·05) neutral detergent fibre digestibility (0·478 v. 0·461) and lower (P<0·01) urinary energy losses (5·2 v. 5·8 % GEI) than sheep. It is suggested that differences between these species in forestomach particulate FOR might have been the underlying physiological mechanism responsible for the differences in CH4 yield, although the between-species differences in VFI and diet quality also had a major effect on it.

As with any measurement procedure, the performance of a subjective classification procedure must be evaluated. Observers have to be trained and their performance has to be assessed, preferably on a regular basis, to guarantee sufficient consistency and accuracy of classification results. The current paper is a study of observer performance where observers were asked to classify the gait of cows from video recordings. Gait was classified in nine ordered categories (ranging from 1=normal gait to 9=severely abnormal gait) and also as a continuous fraction by putting a mark on a paper strip (the left end corresponding to 0=normal gait and the right end to 1=severely abnormal gait). The use of statistical models and methodology for analysis of these visual scores is demonstrated and discussed. Observers were assessed by comparing their classification results with the results of an expert. Models and methodology take proper account of typical features of the data, i.e. the fact that data are discrete scores or continuous scores with an upper and lower bound, the variance heterogeneity and non-linearity of model terms that arises from this, and the dependence between repeated classifications of videos of the same cow. Results of the analyses are summarized in simple tables and plots. These are useful tools to indicate possible flaws in judgement of an observer, that may be corrected by further training. When a high standard is developed, which usually takes the form of the opinion of one or more experts, this methodology can be applied prior to any experiment where responses are ordered subjective scores.

Four low and four high methane (CH4) emitters were selected from a flock of 20 Romney sheep on the basis of CH4 production rates per unit of intake, measured at grazing using the sulphur hexafluoride (SF6) tracer technique. Methane emissions from these sheep were monitored at grazing for four periods (P): October, November, January and February 1999/2000. All measurements were carried out on perennial ryegrass/white clover pasture under generous herbage allowance, and the sheep were maintained on similar pastures during non-measurement periods. The tracer technique was used for all the CH4 measurements and feed DM intake was calculated from total faecal collection and estimated DM digestibility. Data for liveweight (LW), gross energy intake (GEI) and CH4 emission were analysed using split-plot analysis of variance. In addition, a between-period rank order correlation analysis was carried out for CH4 emission data.

Low CH4 emitters were heavier (P<0·05) than the high emitters in all the periods, but they did not differ (P<0·05) in their gross energy intakes (GEI: MJ/kg LW0·75). Low and high CH4 emitters consistently maintained their initial rankings in CH4 yield (% GEI) throughout the subsequent periods and the correlation analysis of rank order for CH4 yield showed strong between-period correlation coefficients, although this was weaker in the last period. It is suggested that feeding conditions that maximize feed intake (e.g. generous allowance of good quality pasture under grazing) favour the expression and persistence of between-sheep differences in CH4 yield.

An experiment combining a hyperinsulinaemic euglycaemic clamp approach and an isotope dilution method determined the effects of cold exposure and time relative to feeding on blood glucose metabolism in four sheep. The sheep, fed 20 g/kg body-weight (BW) of lucerne hay cubes and 5 g/kg BW of maize-based concentrates once daily, were exposed in turn to a thermoneutral environment (20 °C) and a cold environment (0 °C) for 20 days. The combined experiments were performed at four different times relative to feeding, i.e. 3 to 2 h, 2 to 1 h and 1 to 0 h before, and 1 to 2 h after the initiation of feeding for the basal periods, and 1 to 0 h before, and 0 to 1 h, 1 to 2 h and 3 to 4 h after the initiation of feeding for the glucose clamp periods in both environments. [U-13C]Glucose was continuously infused for 6 h after a priming injection. Insulin was continuously infused at 6·0 mU/kg BW per min for 2 h, which corresponded to the last 2 h of the [U-13C]glucose infusion. Blood glucose concentrations were maintained euglycaemic during the insulin infusion by concomitant variable glucose infusion. Blood glucose turnover rate (GTR) during the basal period was enhanced by cold exposure (P=0·01) and feeding (P=0·04). Blood GTR increased (P<0·01) with the glucose clamp. During the glucose clamp, blood GTR and glucose infusion rate (GIR) were greater (P=0·003 and P=0·001, respectively) during cold exposure than in the thermoneutral environment. Time relative to feeding influenced (P=0·003) the GIR, whereas changes in blood GTR and endogenous glucose production rate were not significant. No significant cold×feeding interaction was observed in these variables. It was suggested that, in sheep, glucose metabolism was enhanced by cold exposure and the glucose clamp. It was probable that blood glucose metabolism during the glucose clamp was influenced by cold exposure and feeding, but the combined effect of cold exposure and feeding was not significant.

The outer surfaces of plant leaves and stems are covered with a waxy layer, a considerable fraction of which comprises n-alkanes which are not digested and, therefore, can be used as markers in animal nutrition studies. Most plant species have a characteristic pattern of n-alkane concentrations in their cuticular wax and this enables the diet composition to be estimated by comparison with the pattern of the n-alkanes in faeces. N-alkane recovery in faeces was determined in a digestibility trial involving three different diets given to four goats, six cows and five calves. The validity of using n-alkane markers to determine diet composition was examined in in vivo feeding trials with goats and cows. The recovery of the odd chain length n-alkanes increased linearly with n-alkane chain length, with no significant differences between treatments. Estimates of diet composition were affected by the faecal n-alkane recovery rate. N-alkanes in plant cuticular wax can be used as natural markers for estimating diet composition, but a recovery factor should be used to correct for incomplete recovery in faeces. More research is needed to extend the findings to wider ranges of diets, animals, environmental conditions and physiological and reproductive states.

The gastrointestinal tract (gut) contents of male Zebu cattle (Bos indicus) were studied in the southern Sahelian zone of Mali. Measurements were carried out on 39 animals in mid-dry season (MDS) and 15 at the end of the dry season (late dry season, LDS).

After overnight fasting, the animals were weighed and then slaughtered. The different gut compartments were emptied and representative samples of their fill were analysed for contents of dry matter (all) and NDF (reticulo-rumen only).

Related to fasted live weight (FLW), gut fresh matter (FM) fill (g FM/kg FLW) increased from 165·7±4·81 g in MDS to 227·5±3·05 g in LDS (P[les ]0·001), liquid gut contents (g fluid/kg FLW) increased from 138·9±4·65 to 193·5±2·49 g (P[les ]0·001) and gut dry matter fill (g DM/kg FLW) increased from 26·8±0·88 to 34·0±0·97 g (P[les ]0·001). Fresh matter content of the reticulo-rumen accounted for 77% and 80% of the entire gut FM fill in MDS and LDS, respectively. While the NDF component in reticulo-rumen fill (g NDF/kg DM) increased from 778·5±5·63 g in MDS to 836·6±6·37 g in LDS (P[les ]0·001), the ratio between dry matter and fluid in the reticulo-rumen (g DM/g fluid) decreased from 193·2±10·17 g in MDS to 169·0±5·54 g in LDS (P[les ]0·05).

The data support the notion that African breeds of Zebu cattle adjust to deteriorating feeding conditions by increasing reticulo-rumen dry matter and fluid contents. In-depth studies are needed to quantify the physiological benefits resulting from this strategy.

The composition of animal manure is influenced by the diet fed. Efforts are made to decrease nitrogen emission from pig production by optimizing diet composition. This normally results in a lower proportion of N excreted in urine relative to faeces, and may also influence the turnover and utilization of manure N after field application. The effects of pig feed composition on the excretion of urinary and faecal N, on the dynamics of manure N in soil and on the potential utilization of manure N in the field was studied. Growing pigs and sows were fed 12 different diets with variable contents of fibre and protein (with or without synthetic amino acids). Slurries consisting of a mixture of faeces and urine were stored according to common agricultural practice in Northern Europe. The plant availability of N in the resultant slurries originating from animals fed known diets was tested in small field plots with barley, under conditions with minimal N losses. Separate plots were fertilized with increasing amounts of mineral N. Nitrogen uptake in barley was determined and the utilization of slurry N was compared with that of mineral fertilizer N. The net release of mineral N and C from the slurries in soil was also measured in a parallel incubation study.

The mineral fertilizer equivalent of pig slurry N was 72–100% and significantly influenced by feed fibre composition, but not significantly influenced by the protein content. There was a significant positive correlation between enzyme-digestible organic matter in the pig diet (measurement used for feed evaluation) and the plant availability of pig slurry N (R2=0·90). The ammonium content of stored pig slurry could not be used for prediction of the N availability since the net mineralization of pig slurry N was variable, but there was a significant negative correlation between the pig slurry C/N ratio and the plant availability of slurry N (R2=0·86).

Increased dietary concentration of fermentable structural carbohydrates (e.g. by including sugar beet pulp in the diet) reduces the excretion of N in urine without affecting the availability of slurry total N, whereas an increased concentration of dietary fibre with a low fermentability (straw) results in less urinary N, but also a lower plant availability of slurry N.

To clarify the role of the incisors in selective grazing by cattle and horses, experiments were conducted in July 1999, using three Holstein cattle and three thoroughbred horses to investigate bite weight and bite force using hand-constructed swards with 15 loadcells spaced 6×12 cm apart. Leaves of perennial ryegrass (Lolium perenne: PRG) were mixed with leaves of tall fescue (Festuca arundinacea: TF) or reproductive culms of reed canarygrass (Phalaris arundinacea: RCG).

There was little difference between cattle and horses in bite rate, but DM intake rate of horses was almost twice that of cattle in the PRG/TF mixture. In the PRG/RCG mixture, both animals tended to graze only leaves of PRG. Total bite force was 3270–3280 N/min in cattle and 5350–6350 N/min in horses in the PRG/TF mixture. Means of maximum values of one bite force (not total force per bite) were 88±5·5 N in cattle and 141±11·0 N in horses. These values corresponded to 1·6±0·10% of body weight in cattle and 2·2±0·16% in horses, after converting Newton force into kilogram force. Bite area was higher in horses than in cattle. Both cattle and horses did not discriminate between leaves of PRG and TF. In the PRG/RCG mixture, horses prehended both leaves and culms in 33% of total clumps grazed, compared with only 5% in cattle. Many culms escaped from the mouth at the moment of prehension. In mixtures of soft leaves and stiff stems, the lack of upper incisors in cattle may have the advantage over horses. The term ‘comb-out strategy’ is proposed for this selective foraging by cattle. DM intake per bite force was highest in TF leaves (7·5 mg DM/N) grazed by horses and similar (3·7–4·6 mg DM/N) in PRG leaves grazed by both cattle and horses.

Urinary purine derivative (PD) excretion was estimated to examine the effect of rumen protozoa on total PD excretion in goats fed hay and a concentrate diet. The effect of increasing protozoa number in the rumen on nitrogen (N) balance and urinary PD excretion was determined after inoculation. Protozoa increased slowly until 4 days after inoculation, and on the 5th day after inoculation rapidly, finally (10 days) reaching 4·1×105/ml of rumen contents similar to that before defaunation. Urinary N excretion showed a small (non-significant) decrease. Urinary PD excretion did not change until the 7th day, and then the level decreased on the 8th day after faunation presumably due to the effect of increased protozoa in the rumen. The mean urinary total PD excretion significantly (P<0·05) decreased in the defaunated group compared with that in the faunated group. Comparable changes were not seen in plasma PD level of faunated and defaunated groups.

The effect of base composition biases on codon usage patterns was investigated in the goat species Capra hircus, using custom-designed computational tools available within the public domain. Nucleotide frequencies were nearly equal and a slight increase of adenine–thymine (AT) over guanine–cytosine (GC) was detected throughout the dataset. However, this increase showed no influence on the bases at the third codon position (N3). C3 and G3 were found more often than A/T3, suggesting that there was a small or almost no influence of the general base composition on the N3 base composition. To understand more and analyse in-depth influence and interactions between base compositions and codons, further relative synonymous codon usage (RSCU) was investigated. Amino acid usage and the correlation between its usages were also investigated, using both basic sequence analysis and statistical analysis means (measures of correlation). These analyses were utilized to probe whether there were correlations between genes, genomic characteristics and their function. Genes with high GC and those with low GC were also investigated to see to what extent how a gene functions could influence its sequence structure and impose certain structural modifications. This investigation may shed light on many genomic features of Capra hircus genes and would be of significance for future biotechnology/research projects considering Capra for transgenic and advanced genomic initiatives.