Chicory (Cichorium intybus) is perhaps best known for the extract of its roots used as an ingredient in ‘coffee substitute’ beverages. It is less well known as a grazed forage for ruminants. Thomas et al. (1952) reported the high content of some major and minor trace minerals in chicory grown in the UK, and commented on its use in pasture mixtures as a source of these minerals. Chicory was first mentioned in New Zealand (NZ) literature as an animal forage by Cockayne (1915), but a long period then elapsed before Lancashire (1978) reported its excellent value for forage production under rotational grazing in dry summer conditions. Plant selection then followed and the cultivar ‘Grasslands Puna’ was approved for commercial release as a grazed forage plant in 1985 (Rumball 1986). The use of Puna chicory has now spread throughout NZ and the variety is also being used commercially in Australia, North America and South America and is being evaluated in parts of Europe and Asia (W. Green, personal communication). Chicory is a herb, whereas other temperate forages used for ruminant production are either grasses or legumes. This paper reviews work on the chemical composition, nutritive value and feeding value of chicory relative to perennial ryegrass (Lolium perenne) and to red clover (Trifolium pratense), a legume that, like chicory, is used as a forage for dry summer conditions. Throughout this paper, feeding value is defined as the animal production response to grazing a forage under unrestricted conditions (Ulyatt 1973), with its components being voluntary feed intake (VFI), the digestive process and the efficiency of utilization of digested nutrients; the latter two comprise nutritive value/dry matter (DM) eaten.

Root branching and architecture play a significant role in water and nutrient uptake, but description of these parameters has not been easy due to the difficulty of observing roots in their natural arrangement. Fractal geometry offers a novel method for studying the branching patterns of roots. Plants of ten diverse sorghum (Sorghum bicolor (L.) Moench) genotypes (five of African origin, three of US origin and two hybrids composed of African×US lines) were grown in root boxes containing 80% sand and 20% fine-textured Sharpsburg silty clay loam topsoil. The root fractal dimension (D) and abundance (log K) were determined at nine regions within the profile. Roots were washed free of growth media and photographic slides were taken of each region. Values of D and log K were determined by projecting photographs onto grids of progressively increasing sizes. The number of intersects was regressed on log grid size. Differences in D were found among genotypes (1·44[les ]D[les ]1·89) suggesting that these sorghum genotypes may be associated with greater root branching patterns. Greater fractal dimension (branching) and abundance values occurred in the 0–35 and 35–70 cm depths of the soil profile within the root box, indicating a greater root distribution in that part of the profile. Significant differences were also noted in branching patterns for sorghum genotypes derived from different sources. In general, the African sorghums were more branched and deeper rooted than the US-derived genotypes. Results indicated that fractal dimension can be used for the description of sorghum root system morphology and provides a good measure of branching patterns which can be distinguished.

Nitrate leaching losses from intensively managed monoculture grass and grass–clover pastures were measured during 1994–96 at a long-term experimental farm in south-west Scotland. Field-size lysimeter plots were established in 1993 on the existing pastures on a silty clay loam non-calcareous gley. No fertilizer-N was applied to the grass–clover, while the monoculture grass was fertilized with c. 240 kg N ha−1 year−1, but both swards received 2–3 cattle slurry applications annually (120–390 kg total N ha−1 year−1). The pastures supported 2–3 cuts for silage conservation, and were grazed by dairy cattle and stocked with sheep during the winter months.

Initially, leachate nitrate concentrations from the fertilized grass were considerably larger than those from the clover-based pasture, but became similar with time. The annual nitrate leaching losses from the grass–clover (24–38 kg NO3-N ha−1) were less than that from the monoculture grass (30–45 kg NO3-N ha−1), but the differences were not large considering the additional fertilizer-N applied to the latter treatment. Results also suggested that greater leaching losses occur during a warmer, drier year, compared to a cooler, wetter year, regardless of the source of N-input.

A series of experiments investigating the interactive effects of light and temperature on vegetative growth, earliness, fruiting, yield and fibre properties in three cultivars of cotton, was undertaken in growth rooms. Two constant day/night temperature regimes with a difference of 4 °C (30/20 and 26/16·5 °C) were used throughout the growing season in combination with two light intensities (75 and 52·5 W m−2).

The results showed that significant interactions occurred for most of the characters studied. Although the development of leaf area was mainly temperature-dependent, plants at harvest had a larger leaf area when high temperature was combined with low rather than with high light intensity. Leaf area was least in the low temperature–low light regime. However, the plants grown under the high temperature–low light combination weighed the least.

Variations in the number of nodes and internode length were largely dependent on temperature rather than light. Light did, however, affect the numbers of branches, sympodia and monopodia. The first two of these were highest in the high light–high temperature regime and the third in the low light–low temperature regime.

All other characters, except time to certain developmental stages and fibre length, were reduced at the lower light intensity. Variation in temperature modified the light effect and vice versa, in a character-dependent manner. More specifically, square and boll dry weights, as well as seed cotton yield per plant, were highest in high light combined with low temperature, where the most and heaviest bolls were produced. But flower production was favoured by high light and high temperature, suggesting increased boll retention at low temperature, especially when combined with low light. Low temperature and high light also maximized lint percentage.

Fibres were shortest in the high temperature–high light regime, where fibre strength, micronaire index and maturity ratio were at a maximum. However, the finest and the most uniform fibres were produced when high light was combined with low temperature.

Cultivar differences were significant mainly in leaf area and dry matter production at flowering.

The commercial future of Linum usitatissimum is intrinsically linked to its cultivation as a dual-purpose crop for producing increased seed and fibre yields. The present study evaluates 36 F1 crosses derived from nine linseed/flax accessions for their potential as dual-purpose cultivars and/or their suitability for extracting new recombinants producing high seed yield as well as increased fibre output. The quantitative analysis indicated that variation between the F1 families is largely but not exclusively due to the additive and non-additive (dominance) effects of genes. Dominance is high for plant height (H1), height at maturity (HMT), number of branches (NBr) and seed weight (SdWt) while 100 seed weight (Wt100) displays no dominance at all. The repeatability estimates representing the heritability of each trait, vary from low (0·20) for number of branches (NBr) to high (0·71) for height at flowering time (HFT). The dual-purpose traits such as seed weight (SdWt) and straw weight (StWt) were only moderately inherited while flowering time (FT) and various heights were rather highly heritable. A moderate and positive correlation (r=0·57) between StWt and SdWt, and a completely independent inheritance of Wt100 suggested that there are good chances of combining these traits into a single genotype. The phenotypic performance of the crosses also confirmed this trend and at least four crosses showed superior performance for both SdWt and StWt compared to their parental lines. All these crosses involved a linseed line (B3) as a common parent and the second parent was either another linseed line (A1 and A3) or a flax accession (K3 and L2); none of the flax×flax crosses showed good potential for seed yield. While all four crosses possess the potential to become highly productive, dual-purpose, hybrid varieties, the extraction of desirable inbred lines from them, however, may prove difficult because the superior performance of the hybrids seems largely due to strong unidirectional dominance and high SCA effects.

Field experiments were conducted on Alfisols in Nigeria between 1991 and 1993 to determine the residual effect of maize (Zea mays) and cowpea (Vigna unguiculata) on the growth, pod yield and N response of a succeeding okra (Abelmoschus esculentus) crop. Cowpea and maize were grown alone with 30 and 60 kg/ha of N, P and K, respectively, or intercropped with 60 kg/ha as a basal dressing. The preceding crops had a significant effect on soil nutrient changes, okra growth and yield, and N response of okra. Cowpea increased the N, P and K status of the soil in both sole and mixed stands, compared with sole maize. Leaf area, pod weight and marketable pod yield of okra after sole cowpea or the maize/cowpea intercrop were all significantly higher than after sole maize. Although the application of nitrogen to succeeding okra promoted growth and increased pod yield, this was not accompanied by an increase in the pod yield of okra after sole cowpea or the maize/cowpea treatment beyond 45 kg N/ha. The beneficial effects of the preceding maize/cowpea intercrop on soil fertility, okra pod yield and amounts of N required for okra were partly due to the higher rate of basal nutrients applied as compared to the effects following sole cowpea.

Two field experiments in Canterbury, New Zealand, were conducted during 1993–95 following the ploughing of temporary pasture leys. These experiments investigated the effects of cover crop management on the accumulation of soil mineral N and nitrate leaching during winter, and the growth and N uptake of the following spring cereal crop. The cover crops used were ryegrass (Lolium multiflorum L.), oats (Avena sativa L.), lupins (Lupinus angustifolius L.), mustard (Sinapis alba L.) and winter wheat (Triticum aestivum).

Ploughing of temporary pasture in autumn (March) resulted in extensive net N mineralization of organic N by the start of winter (June). In fallow soil, mineral N in the profile in June ranged from 98 kg N/ha in 1993 to 128 kg N/ha in 1994. When cover crops were established early in the autumn (March) in 1993, both the above-ground dry matter production (1440–3108 kg DM/ha) and its N content (50–71 kg N/ha) were substantial by the start of winter. In 1994, establishment of cover crops one month later (April) resulted in very little dry matter production and N uptake by June. In both years, compared with fallow soil, winter wheat planted in May had little effect on soil mineral N content by the start of winter.

Compared with fallow, cover crops had little effect on soil drainage over winter. Cumulative nitrate leaching losses from fallow soil were much smaller in 1993 (23 kg N/ha) than in 1994 (49 kg N/ha), mainly due to differences in rainfall distribution. Cover crops reduced cumulative nitrate leaching losses in 1993 to 1–5 kg N/ha and in 1994 to 22–30 kg N/ha. When cover crops were grazed, soil mineral N contents were increased due to the return of ingested plant N to urine patch areas of soil. Elevated soil mineral N contents under grazing persisted throughout the winter. Grazing had little effect on cumulative nitrate leaching losses, mainly because of the small amount of drainage that occurred after grazing in either year.

Compared with fallow, incorporation of large amounts of non-leguminous above ground dry matter depressed the yield and N uptake of the following spring-sown cereal crop. Where cover crops were grazed, yields of the following cereal crops were similar to those for soil fallow over the winter.

Nitrate loss in drainwater and cultivated layer flow was measured over 5 years on two pairs of hydrologically isolated plots, one pair with cereal straw incorporated for 4 years and burnt in the fifth, and the other with straw burnt in all 5 years. Although straw incorporation decreased nitrate leaching and probably decreased net mineralization of soil organic matter in the first winter, these effects were apparently diminished or even reversed in later winters, and the straw had no benefit on cereal yields or N-uptakes. The results suggest that the present practice on UK farms of regularly incorporating cereal straw is unlikely to decrease nitrate losses and in the long term may increase them, especially on clay soils and in wet winters after long dry periods. On clay soils it is also unlikely to increase crop yields in the short or medium term.

Four, 4-week old Friesian calves (BW=50±3 kg), fitted with duodenal, portal and jugular catheters and duodenal electrodes, were used to study the metabolism of duodenally infused betaine (Bet) or choline (Chol) and their effects on blood sulphur amino acids and duodenal myoelectrical migrating complexes (MMC). Animals were fed milk replacer at 5% BW twice daily, but were starved overnight prior to the experimental procedure. Animals received a saline infusion for 2 h at 1 ml/min followed by a 1 h infusion of 1·2 or 3·6 mmol of either Bet or Chol. Infusion of saline was continued for another 2 h after the cessation of the amino acid infusion. Duodenal MMC were measured with a computer-based data acquisition system (MacLab, ADI, Australia). There were no differences in measured blood metabolites between the jugular and portal vein; therefore, only average values were presented. Plasma Met concentrations increased from 20 μm, 20 min after initiating Bet infusion, whereas a lower dose of Chol decreased plasma Met and a higher one had no effect. The highest plasma methionine (Met) concentration (29 μm) occurred 45 min after the onset of the Bet infusion (1·2 mmol). Compared to the 3·6 mmol Bet infusion, the intraduodenal infusion of 1·2 mmol of Bet resulted in a greater area (P<0·001) under the plasma Met concentration curve (281·6 v. 73·3 mmol). A similar pattern was observed for plasma cystine concentrations. Infusion of Bet or Chol did not change the duration of MMC but Bet increased the number of spikes during the phase of low spiking activity (37·5 v. 14·6 pre-infusion, spikes/min; P<0·01). Chol had the same effect but only after the infusion ceased (29·3 v. 11·5 spikes/min; P<0·01). The velocity of migration of regular spiking activity (RSA; related to digesta transport) increased as a result of infusion (16·4 pre-infusion v. 31·3 Bet, 25·2 Chol cm/min; P<0·01). Chol caused an immediate increase in the velocity of migration of RSA, whereas with the Bet infusion an increase was observed after cessation of infusion. Increased concentrations of sulphur amino acids during Bet infusion could indicate that labile methyl groups may be limited in calves. Postruminal Bet and Chol supplementation may cause a decrease in nutrient absorption in the small intestine by increasing digesta transport.

Growth, body composition and distribution of carcass tissues were compared in Omani sheep and goats. Animals had ad libitum access to Rhodes-grass hay (8 % CP) and a concentrate diet (16% CP) from weaning until slaughter. The two species had similar birth weights but sheep had higher preweaning (181 g/day), postweaning (175 g/day) and overall (179 g/day) growth rates than goats (120, 102 and 111 g/day, respectively) and thus they reached slaughter weights earlier. Sheep had higher slaughter weight (22·26 kg), empty body weight (20·39 kg), hot carcass weight (12·48 kg) and dressing out percentage (55·94%) than goats (21·17, 18·82, 11·48 kg and 53·97%, respectively). Sheep also had higher proportions of skin, liver and lungs and trachea (P<0·01) than goats, which had higher proportions of head, feet and gut contents. As proportions of carcass weight, sheep had higher fat (25·08%) but lower muscle content (57·24%) than goats (15·72 and 65·88%, respectively). There were no significant differences between the two species in proportion of carcass bone (13·76 and 14·17%). These effects resulted in sheep having a lower muscle: bone ratio (4·19 and 4·68) and higher fat: muscle ratio (0·44 and 0·24). Sheep had higher proportions of non-carcass, carcass and total body fat in the empty body weight (EBW) than goats. However, sheep had less non-carcass but more carcass fat than goats when fats were expressed as proportions of total body fat. Sheep had higher proportions of muscles in the proximal hind limb, distal hind limb (P<0·01), around the spinal column, connecting forelimb to thorax and high-priced muscle group (P<0·05), but lower proportions of muscles in the abdominal wall, proximal forelimb (P<0·05), distal forelimb (P<0·01), connecting neck to forelimb, intrinsic muscles of neck and thorax (P<0·05) and total forequarter muscles (P<0·01) than goats. As proportions in carcass bone, sheep had higher axial skeleton (P<0·05) but lower forelimb than goats. Among species/sex/slaughter weight groups, castrated male and female goats had the lowest growth rates. Castrates and female sheep, particularly at heavier liveweights, had higher carcass and non-carcass fat contents than intact males and goats of all sexes. Although Omani goats produced leaner carcasses and had higher proportions of some non-carcass offals than Omani sheep, they had slower growth rates and a less attractive muscle distribution. This may negatively affect their potential for large scale meat production under Omani conditions.

A study on the energy expenditure of sheep was carried out at the Central Sheep and Wool Research Institute, India during August 1995 to July 1996 by conducting two experiments: one on tracheal cannulated rams maintained on stall-feeding in autumn 1995 (Expt 1) followed by year-round grazing on silvipasture (Cenchrus ciliaris pasture interspersed with fodder trees) over three seasons: monsoon, winter and summer, 1995/96 (Expt 2). Physiological responses and energy expenditure measurement of housed and grazing sheep were recorded at 06.00, 14.00 and 22.00 h for 5 consecutive days in each season. Tracheostomized sheep harness with meteorological balloon were used for collection of expired air and measurement of energy expenditure. Rectal temperature (RT) of sheep at 06.00 h was similar in all the seasons except for a significant (P<0·05) lower value in monsoon. The rise of RT from 06.00 to 14.00 h in grazing animals was 1·6 °C, higher than that in housed sheep (0·9 °C). Skin temperature (ST) was least in winter and highest at 14.00 h in the monsoon and autumn seasons. Respiration rate (RR) showed a marked rise at 14.00 h in all the seasons. The heart rate (HR) of grazing sheep was higher, irrespective of season, at 14.00 h. At 06.00 and 22.00 h, the heart rate was higher in winter and summer than in the monsoon season. Overall energy expenditure (EE) was 4·85 MJ/24 h during winter which increased to 5·85 MJ/24 h in summer and 6·70 MJ/24 h in the monsoon. The mean rise in energy expenditure per °C rectal temperature in all the seasons was 338 kJ/kg W0·75. Comparable mean values per 10 °C ambient temperature and 10 °C black globe temperature were 404 and 173. The increase in energy expenditure of grazing compared to housed sheep in monsoon, winter and summer was 78, 15 and 33 % respectively. The mean value was +43%.

Spring postpartum reproductive performance was investigated in 19 Awassi and 15 Finn×Texel×Awassi (FTA) crossbred ewes, weaned at 2 months postpartum and simultaneously exposed to rams for a period of 48 days. The study was conducted in 1991/92 in the Bekaa Valley of Lebanon.

Postpartum FTA ewes tended to have higher fecundity and prolificacy than those of Awassi ewes. Forty percent of the FTA ewes conceived and gave birth to 1·3 lambs per lambing, while 31·4% of the Awassi ewes conceived and lambed (1·1 lambs per lambing). Lambing to lambing and ram introduction to lambing intervals were similar in both genotypes and confirmed that a sizeable proportion (30–40%) of Awassi ewes and their crosses may rebreed during spring postpartum anoestrus and lamb at c. 8 months interval. Furthermore, relative progesterone values revealed continuous ovarian activity in 16% of Awassi ewes and 40% of FTA ewes and confirmed estimates of conception in ewes. All ewes with continuous ovulation mated and lambed. Weekly estimates of milk production over a 2-month period, starting the second week of lactation, showed that daily milk yields were almost twice as much in Awassi as in FTA ewes (P<0·01). These results indicate the potential for Awassi ewes and their crosses to be incorporated into frequent lambing systems. Reproductive efficiency in these ewes could be monitored efficiently by measuring progesterone at 2-weekly intervals.

Five grazing trials using Suffolk wethers were carried out at Obihiro, Japan from June to July of 1989 and 1990. New methodology was developed to investigate bite weight and bite selection using hand-constructed swards, which were composed of 128 points of plant units spaced 4 cm apart. Leaves and reproductive culms of orchardgrass (Dactylis glomerata) and timothy (Phleum pratense) were used in five kinds of artificial swards (three pure leaf mixtures and two leaf/culm mixtures).

In the leaf/culm mixture, sheep definitely selected leaf units. The inclusion of reproductive culms decreased the number of prehending bites and the total distance of travel between bites. Mean distance of travel between bites was 8·6–10·6 cm. Mean travelling speed was 7·2 cm/s and was not influenced by the inclusion of culms. Total distance of travel between bites was 3·8–4·1 m/min in pure leaf mixtures and 3·4–3·5 m/min in leaf/culm mixtures.

The actual area covered by one prehending bite, estimated from direct measurement, was 21–27 cm2 in pure leaf mixtures and 15–16 cm2 in leaf/culm mixtures. Decreased bite area in leaf/culm mixtures resulted in decreased bite weight and intake rate. Experimental errors observed were discussed with respect to the biting behaviour of sheep and flexibility of grass leaves.

The influence of dietary nutrient concentration on performance and the growth of fat depots, breast meat and leg muscles was examined in five groups of male broiler chickens fed ad libitum with combinations of high (H), commercial (C) or low (L) energy and nutrient concentration in starter and finisher diets. Diets were changed from starter to finisher at 3 weeks of age giving 200 birds on each of five treatments: HH, HL, CC, LH and LL. Ten birds per treatment were slaughtered at weekly intervals from 0 to 70 days. Five of these were dissected into component lean tissues of breast muscles (white meat) and thigh+leg muscles (dark meat) and fat depots, and the other five carcasses were minced for chemical analyses. Data were analysed by fitting Gompertz functions to each component.

Analysis of body weight, carcass components and feed intake revealed that at 70 days birds on LH approached similar liveweights to those on HH with lower overall food intakes, comparable feed conversion ratios but slightly greater fat depots. The HL birds had less fat but achieved specific weights over longer periods of time with greater feed intakes and poorer feed conversion ratios. Content of white and dark meat was always greater in HH birds, with differences between treatments being greater for white meat.

Decisions on which conditions are most appropriate will be influenced by time taken to reach specific liveweights if whole birds are marketed, or the rate of growth of individual portions if further processing is considered, together with feed conversion efficiency and the relative costs of diets varying in energy and nutrient concentration.