It is generally accepted that sucrose phosphate synthase (SPS), sucrose synthase (SuSy), ADP-glucose pyrophosphorylase (AGPase), soluble starch synthase (SSS), granule-bound starch synthase (GBSS) and starch branching enzyme (SBE) play a key role in starch synthesis in wheat grains. Starch synthesis in wheat grains is influenced by genotype and environment. However, what is not known is the degree of variation in enzyme activities during starch accumulation of wheat cultivars field-grown in different water regimes. The present study was undertaken to determine whether irrigation patterns could cause differences in starch accumulation and activities of key enzymes involved in starch synthesis. Starch accumulation and related enzyme activities were investigated in two winter wheat varieties, JM20 and BY535, differing in grain starch content, under two irrigation patterns. Results showed that soil water deficit led to an increase at early grain filling and decrease during late grain filling in starch accumulation rate (SAR) and activities of key enzymes involved in starch synthesis, especially AGPase, SSS and SBE. Water deficit enhanced grain starch accumulation in two wheat cultivars, suggesting that rainfed treatments increase physiological activities during early grain filling and promote starch accumulation. Furthermore, the change of SAR is consistent with SuSy, AGPase, SSS and GBSS. The results suggest that these enzymes play a key role in starch synthesis, and the decrease of photosynthate produced in the source organ is not the factor inhibiting starch accumulation.

Fifty-two genotypes of rice bean (Vigna umbellata Thunb. (Ohwi and Ohashi)), an under-cultivated crop, were evaluated in the rainy (kharif) seasons of 2001, 2002 and 2003 in the North Eastern Hill Region, India to select suitable genotypes for cultivation in the North Eastern Hill region and to identify promising parents for hybridization programmes. The germplasm studied comprised 44 Indian and eight foreign genotypes. A wide range of variability was observed for eight characters studied (plant height, number of branches/plant, stem thickness, pod length, number of seeds/pod, 100-seed weight, pod weight/plant and seed yield/plant). Number of days to mid-flowering and number of days to maturity showed little variation. High heritability (0·58) and high genetic advance (0·53) were observed for 100-seed weight, high heritability (0·93) and moderate genetic advance (0·37) for seed yield/plant, and high heritability (0·60) and low genetic advance (0·13) for number of days to mid-flowering. Since the main aim in rice bean breeding is to develop high yielding, early maturing genotypes with low plants, selection was based mainly on the mean performance of these three traits over the 3 years, as well as their stability. One of the genotypes, RBL 1, was very high yielding, although the yield was not stable across years. Another genotype, RBS 24, was very early maturing and had very short plants compared with the other genotypes studied. These two, along with several other genotypes selected, may be promising for a hybridization programme aiming to develop dwarf, early maturing genotypes with high yield. The best yielding genotypes, namely RBL 1, RCRB1-3 and IC 187911, may be recommended for cultivation in the shifting cultivation areas (Jhum) regions of North Eastern India.

Twenty Holstein cows were split into two equal groups to test the effect of daily move to a previously ungrazed strip after morning milking (MA) or afternoon milking (AA) on herbage intake, grazing behaviour, rumen characteristics and milk production using a randomized block design with three periods of 14 days each. Milking took place at 06.00 and 16.00 h. The chemical composition of grass was similar between treatments, but an interaction between treatment and time of sampling was found in all variables except acid detergent lignin (ADL). The most pronounced differences existed in sugar content. Grass sugar content was greatest following afternoon milking. However, the difference in sugar content in grass was much larger in MA (158 v 114 g/kg dry matter (DM) at 16.00 and 06.00 h, respectively) than in AA (147 v 129 g/kg DM at 16.00 and 06.00 h, respectively). Neutral detergent fibre (NDF) was significantly higher at 06.00 h than at 16.00 h (469 v 425 g/kg DM) in AA, but was equal between morning and afternoon in MA (453 g/kg DM). Herbage intake, determined using the n-alkane technique, did not differ between treatments. Grazing behaviour observed using IGER graze recorders were similar between treatments, except for ruminating time, bite rate and the number of ruminations and boli per period of the day. However, interactions between treatment and time in grazing behaviour variables were found. Grazing time was longer and number of bites was greater following allocation to a new plot (after milking in the morning in MA or milking in the afternoon in AA) when compared to allocation to the same plot after the subsequent milking per treatment (after milking in the afternoon or morning in MA and AA, respectively). In comparison to AA, grazing time in MA was more evenly distributed during the day but lower during the night. The combined effects of differences in grazing behaviour and chemical composition of the grass between treatments in different periods of the day probably caused higher intake of sugars in AA, resulting in a significantly higher non-glucogenic to glucogenic volatile fatty acid ratio (NGR) in the rumen in AA than MA. Milk fat content was lower in MA than AA, but milk production and milk protein and lactose content did not differ. In conclusion, time of allocation to a fresh plot altered the distribution of grazing behaviour variables over the day, and affected NGR and milk fat content, but herbage intake and milk production were not changed.

Twelve sorghum lines resistant to sorghum shoot fly were evaluated for their combining ability for shoot fly resistance and traits associated with resistance, using three male sterile lines in two environments. Using a completely randomized block design with three replications, 36 hybrids and 15 parental genotypes were raised. Considerable genetic variation was observed for all the traits studied. Non-additive gene effects played an important role in governing glossiness, seedling vigour and proportion of plants with deadhearts. For trichome density, both additive and non-additive gene actions were important. Among the lines evaluated, those identified to be good combiners were SFCR 1047 for seedling vigour, deadheart proportion and trichome density, RSE 03 for glossiness, deadheart proportion at 21 DAE and trichome density, and SPSFR 94032 for seedling vigour and shoot fly eggs per plant. Genetic diversity and cluster analysis grouped the 15 parents (12 resistant and 3 susceptible parents) into five clusters. Utilization of the resistant lines belonging to different clusters in improving shoot fly resistance in sorghum is discussed.

The export of Ataulfo mangoes to the US market involves a mandatory hot water treatment and further handling at 13°C for 4 days. These treatments have proven to adversely affect fruit ripening, mainly in colour and flavour development, and their nutritional quality. The application of exogenous ethylene (100 μl/l of air for 12 h at 25°C) to Ataulfo mangoes that were treated with hot water after storage for 4 days at 13°C, and then transferred to 25°C for ripening, was evaluated. Sugar content, colour development and textural firmness were monitored. Control fruit were held at 25°C with no previous refrigeration or ethylene exposure; another batch was kept refrigerated for 4 days at 13°C, not treated with ethylene and ripened at 25°C. Synthesis of fructose (30 g/kg fresh weight (FW)), glucose (38 g/kg FW), sucrose (120 g/kg FW) and β-carotene (0·026 g/kg FW) in the last day of storage was greater in fruits treated with ethylene than on refrigerated mangoes (RM). Loss of firmness (9·3 Newtons) coincided with the highest pectinmethylesterase and polygalacturonase activities, 53·24 and 37·92 U/mg protein, respectively, and eventually led to collapse of cell structure. Results suggest that sugars and carotenoid content can be increased, along with an accelerated ripening by application of exogenous ethylene on mangoes that were refrigerated for 4 days.

Yam minisett technique (YMT) has been promoted throughout West Africa since the 1980s as a sustainable means of producing clean yam planting material, but adoption of the technique is often reported as being patchy at best. While there has been much research on the factors that influence adoption of the technique, there have been no attempts to assess its economic viability under ‘farmer-managed’ as distinct from ‘on station’ conditions. The present paper describes the results of farmer-managed trials employing the YMT (white yam: Dioscorea rotundata) at two villages in Igalaland, Kogi State, Nigeria. One of the villages (Edeke) is on the banks of the River Niger and represents a specialist yam environment, whereas the other village (Ekwuloko) is inland, where farmers employ a more general cropping system. Four farmers were selected in each of the two villages and asked to plant a trial comprising two varieties of yam, their popular local variety as well as another variety grown in other parts of Igalaland, and to treat yam setts (80–100 g) with either woodash or insecticide/nematicide+fungicide mix (chemical treatment). Results suggest that while chemical sett treatment increased yield and hence gross margin compared with woodash, if household labour is costed then YMT is not economically viable. However, the specialist yam growers of Edeke were far more positive about the use of YMT as they tended to keep the yam seed tubers for planting rather than sell them. Thus, great care needs to be taken with planning adoption surveys on the assumption that all farmers should adopt a technology.

The purpose of the present study was to investigate the effects of seven maize (Zea mays)–fallow rotation and fallow residue management treatments on growth, maize yield and soil carbon within a savannah-forest farming zone of Ghana. Over a 4-year period, maize rotated with bare fallow (control) produced an average maize biomass and yield of 4·0 and 1·0 t/ha/yr, respectively. Maize rotated with elephant grass (Pennisetum purpureum) with the fallow grass residue burning produced an average maize biomass and yield of 8·0 and 2·0 t/ha/yr, respectively. The removal of the fallow grass biomass (9·0 t/ha/yr) by burning resulted in a low total residue (maize stover+fallow residue) returned to the soil (7·0 t/ha/yr). The total residue returned to the soil was 14·0 t/ha/yr. Despite the larger total residue returned to the soil by the incorporation treatment, the performance of the maize was not significantly different from that of the fallow residue burning treatment. Maize rotated with cowpea (Vigna unguiculata), mucuna (Mucuna pruriens) or pigeon pea (Cajanus cajan) produced similar maize biomass of 8·0 t/ha/yr and yields of 2·0 t/ha/yr, but with higher variability for the maize–cowpea rotation. Biomass produced by fallow cowpea, mucuna or pigeon pea were 4·0, 5·0 and 8·0 t/ha/yr, respectively, and total residues added to the soil were 13·0, 13·0 and 15·0 t/ha/yr, respectively. Maize–grass rotation with fertilizer application to the maize resulted in biomass and yield production of 11·0 and 3·0 t/ha/yr, respectively, and fallow grass production of 12·0 t/ha/yr. The total residue returned to the soil was 18·0 t/ha/yr. Soil organic carbon (SOC) declined under all treatments over time, with the control losing about 55% of the initial SOC by the end of the trial. The decline in SOC was 19% for the fertilized maize–grass rotation, but all other treatments lost between 33 and 44% SOC. Overall, the fertilized maize–grass and maize–pigeon pea rotations were identified as those that sustained relatively high maize yields, returned large residue amounts to the soil and minimized soil carbon loss.

Chickpea (Cicer arietinum L.) is an important legume of rainfed farming systems, contributing to the sustainability of production and reducing the need for nitrogen (N) fertilization through fixing atmospheric N2. The relative importance of factors causing variations in growth, seed yield, N accumulation and N utilization efficiency among spring chickpea varieties grown in a Mediterranean-type climate was investigated in field experiments conducted in 2003 and 2004. Five chickpea varieties were grown in a silty clay soil in the farm of the Democritus University of Thrace in Orestiada, Greece. Yearly differences in plant growth and productivity were observed and were mainly associated with the variations in the weather parameters between the growing seasons. Nitrogen utilization efficiency (NUE) for biomass production during the seed-filling period was higher compared with that during the vegetative period. NUE for seed yield (SY) ranged from 18·3 to 24·5 g dry matter (DM)/g N and was positively correlated with seed yield, suggesting that high SY was associated with more efficient exploitation of N. When the environmental conditions favoured high early N accumulation, the differences among varieties in NUE were mainly due to the differences in N partitioning at maturity, e.g. the nitrogen harvest index (NHI). The amount and the efficiency of N content at the beginning of seed growth (growth stage (GS) R5) that was translocated to the seed differed among varieties and ranged from 7·0 to 16·6 g N/m2 and from 68·2 to 86·8 g DM/g N, respectively. Most of the variation (0·96) between varieties in N translocation could be accounted for by the differences in total N content at GS R5. N losses from the plant foliage between 0·61 and 9·92 g N/m2 were detected during the seed-filling period when SY was low and N content at GS R5 was high.

This group, which is concerned with the applications of mathematics to agricultural science, was formed in 1970 and has since met at approximately yearly intervals in London for one-day meetings. The forty-first meeting of the group, chaired by Dr Derek Rose of the School of Agriculture, Food and Rural Development, University of Newcastle upon Tyne, was held in the Kohn Centre at the Royal Society, 6–9 Carlton House Terrace, London, on Friday, 3 April 2009 when the following papers were read.

Breed additive and non-additive effects as well as genetic parameters for calving interval (CI), days open (DO), age at first service (AFS), age at first calving (AFC), number of services per first conception (NSC) and breeding efficiency (BE) were estimated in Ethiopian Boran cattle and their crosses with Holstein Friesian in central Ethiopia. The data analysed were spread over 15 years (1990–2004). The Ethiopian Boran cattle had longer CI and DO, lower BE and delayed AFS and AFC compared with all the crosses. However, there was no significant difference in NSC between the genetic groups. Comparison between the crosses revealed no clear cut superiority of any of the genetic groups except for CI and DO which were shorter for 0·50 and 0·875 crosses compared with the 0·75 crosses. The additive breed differences between Ethiopian Boran and Holstein Friesian for CI, DO, NSC and BE were not significant (P>0·05). These estimates are also associated with large standard errors. The non-significance of the otherwise large difference (40 days for CI for instance) between the two breeds could be a result of a large variation (and hence standard errors) associated with the traits. On the other hand, the estimates for additive direct effects for AFS and AFC were negative and significant (P<0·01). The estimates were −7±2·1 and −7±2·8 months, respectively. The individual heterosis values were not significant (P>0·05) for CI, DO, NSC and BE. However, significant (P<0·01) estimates for AFS and AFC (P<0·05) were recorded. None of the maternal heterotic effects for reproduction traits were significant (P>0·05) except for AFC, for which positive (2·9 months) and significant (P<0·05) estimates were obtained. Heritabilities of CI, DO, AFS, AFC, NSC and BE for crosses were 0·1±0·046, 0·1±0·047, 0·6±0·145, 0·7±0·159, 0·1±0·071 and 0·6±0·156, respectively. Selection coupled with improved herd reproductive management should substantially improve the reproductive performance of the indigenous Ethiopian Boran breed under such production system.

The objective of the current study was to evaluate the effects of calcium propionate supplementation on rumen fermentation, urinary excretion of purine derivatives (PD) and feed digestibility in the total gastrointestinal tract of steers. Eight ruminally cannulated Simmental steers (462±14 kg) were used in a replicated 4×4 Latin square arrangement of treatments with experimental periods of 21 days. The treatments were: control (without calcium propionate), LCaP (calcium propionate – low), MCaP (calcium propionate – medium) and HCaP (calcium propionate – high) with 100, 200 and 300 g calcium propionate per steer per day. Diet consisted of 0·60 maize stover and 0·40 concentrate (dry matter (DM) basis). DM intake (average 9 kg/day) was restricted to a maximum of 0·90 of ad libitum intake. Ruminal pH (range of 6·7–6·5) linearly (P<0·003) and quadratically (P<0·005) decreased, and total volatile fatty acid (VFA) concentration (range of 64·4–67·1 mm) tended (P<0·087) to increase linearly with rising calcium propionate supplementation. Ratio of acetate to propionate fell linearly (P<0·006) and quadratically (P<0·008) from 3·5 to 2·6 as calcium propionate supplementation increased due to the additional propionate supplementation. In situ ruminal neutral detergent fibre (NDF) degradation of maize stover and crude protein (CP) degradability of concentrate mix were improved with increasing concentration of calcium propionate. Urinary excretion of PD was linearly (P<0·032) and quadratically (P<0·048) increased with greater calcium propionate supplementation (72, 74, 77 and 76 mmol/day for control, LCaP, MCaP and HCaP, respectively). Similarly, digestibilities of organic matter (OM), NDF and CP in the total tract were also linearly and quadratically improved with increasing calcium propionate. The results indicate that the calcium propionate supplementation potentially improves rumen fermentation and feed digestion in beef cattle. It is speculated that calcium propionate stimulates the digestive microorganisms or enzymes in a dose-dependent manner. In the experimental conditions of the current trial, the optimum calcium propionate dose was about 200 g calcium propionate per steer per day.

Information about changes associated with advances in crop productivity is essential for understanding yield-limiting factors and developing new strategies for future breeding programmes. National bread wheat (Triticum aestivum L.) yields in Turkey have risen by an average of 20·8 kg/ha/year from 1925 to 2006. Annual gain in yield attributable to agronomic and genetic improvement averaged c. 11·6 kg/ha/year prior to 1975, but is now averaging c. 15·1 kg/ha/year. In the Mediterranean region, however, the wheat yield trend line (10·9 kg/ha/year) is c. 0·38 lower than that of Turkey. In order to understand whether such a trend was due to the cultivars released over the years, 16 bread wheat cultivars, commonly grown in the region and representing 23 years of breeding, introduction and selection (from 1976 to 1999), were grown in a randomized complete block design with three replicates across 2 years. Data were collected on maturation time, plant height, spike length, spikelet number/spike, grain number/spike, grain weight/spike, 1000 seed weight, harvest index and grain yield. None of the measured plant traits showed any historical cultivar patterns; therefore, the increase in grain yield could not be attributed to a single yield component. Several physiological traits changed during two decades of cultivar releases in the Mediterranean region that led to a genetic gain in grain yield of about 0·5% per year. Years of data and the present field study in the Mediterranean region suggested that the genetic improvement in wheat seemed inadequate and should be reinforced with modern agricultural management practices as well as technological innovations.

In many plant species, several physiological and biochemical changes occur during low-temperature-induced cold acclimation. A previous study with olive cultivars (Cansev et al.2009) demonstrated a correlation between the level of accumulation of certain leaf proteins besides antioxidative enzyme activities and cold hardiness of the cultivars. The present paper analysed soluble sugar (SS) and phospholipid (PL) contents of cold-acclimated (CA) and non-acclimated (NA) leaf tissues in order to explain the mechanism of cultivar-dependent response to cold in olive. In general, cold acclimation significantly increased total soluble sugar (TSS), reducing sugars and sucrose contents of all cultivars to various extents depending on the cold hardiness of cultivars. In addition, TSS, reducing sugars and sucrose contents in cold-tolerant cultivars were significantly increased, whereas TSS, reducing sugars and sucrose contents in cold-sensitive cultivars either did not change or increased slightly in CA stage compared with those in NA stage. Even though reducing sugars were the major soluble sugar in olive leaves, levels of sucrose accumulations in CA stage compared with those in NA stage were greater than those observed in reducing sugars accumulation. Changes in levels of total PL, as well as the three individual PL fractions phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol (PI), were investigated in olive leaf tissues. Significant increases in levels of PC and PE fractions during CA compared with those in NA stage suggested that PC and PE maintained the cold hardiness of olive cultivars more effectively than did PI. Although the precise mechanisms by which olive responds to cold may still be open to discussion, soluble sugars and PL are clearly important in the ability of olive cultivars to stand against cold stress.

Genotype×environment interaction (GEI) is a major factor in the development of stable and high-yielding safflower cultivars under rain-fed conditions. In order to quantify GEI effects on the seed yield of 17 safflower genotypes and to identify stable genotypes, multi-environment yield trials (multi-environment trials (MET)) were conducted for four consecutive years in 33 different environments (year–location combinations) during 2003–06. The results indicated that GEI was significant using the Hildebrand (1980) procedure for non-crossover interaction (no change in genotypic rank) and by the Azzalini & Cox (1984) and the De Kroon & Van Der Laan (1981) tests for crossover interaction (change in genotypic rank). The rank-interaction was not significant when assessed using the Bredenkamp (1974) method. Fifteen univariate stability methods measuring different aspects of stability were used to determine stable genotypes. A principal component analysis based on rank correlation matrix separated those methods based on a dynamic concept of yield stability (change in genotypic performance corresponds to the predicted level for each environment) from those which are based on a static one (the lowest changes in genotypic performance across environments). The methods could be grouped into three distinct classes: (i) those which were associated with yield level and the dynamic concept of stability; (ii) those which were associated with environmental variance, which represents static stability; and (iii) those which were grouped with non-parametric stability statistics, which also represent static stability. The superiority index of cultivar performance, coefficient of regression, Rank-Sum (sum of ranks of yield and stability variance) and TOP (number of environments at which the cultivar occurred in the top third of the ranks) defined the dynamic stability.

In this MET, the genotype PI-537598 was identified as the genotype with the highest yield and high stability of yield.

White or Guinea yam (Dioscorea rotundata), grown for its underground tubers, is an important food in West Africa. Progress in yam breeding is constrained by variable flowering behaviour, making hybridization difficult. Yam clones may be dioecious, monoecious or hermaphrodite with variable sex ratios. The proportion of plants that flower and the flowering intensity also vary with season and location. The objective of the present work was to investigate whether variation in flowering behaviour was related to factors determining rate of development (photoperiod and temperature through sowing date, location and year) or growth (cumulative solar radiation and temperature). Sex ratios, the proportion of plants that had flower buds and open flowers, and the number of flowers or spikes was recorded in one male (TDr 131) and one female (TDr 99-9) clone of white yam grown in the field in Nigeria at three locations and at different sowing dates. Clone TDr 131 was uniformly male flowering, while clone TDr 99-9 exhibited a number of sex types with gynoecious, monoecious and trimonoecious plants observed. The proportion of flowering plants was low in both clones, averaging 0·34 in clone TDr 131 and 0·13 in clone TDr 99-9. Day of vine emergence had a significant and contrasting effect on the proportion of flowering plants and on flowering intensity in the two clones. In clone TDr 131, the proportion of flowering plants and flowering intensity declined with later vine emergence at all locations (r=0·43–0·53; P<0·05), whereas in clone TDr 99-9 the proportion of flowering plants increased with later emergence (r=0·46, P<0·01). In clone TDr 131, this response was strongly associated with warmer temperatures (r=0·49–0·50; P<0·05) and greater cumulative radiation (r=0·85–0·93; P<0·001) between vine emergence and flowering, rather than photoperiod at vine emergence. This suggests that flowering behaviour in the male clone TDr 131 is strongly influenced by factors that affect growth rather than development. Clone TDr 99-9, on the other hand, exhibited no clear relations between flowering and growth or developmental factors, though the proportion of flowering plants and flowering intensity was greatest at planting dates close to the longest day and at temperatures of 25–26°C. This might suggest that flowering behaviour in clone TDr 99-9 is controlled by photothermal responses.

The current study investigated the effect of offering concentrate supplement to ewes in late pregnancy on twin- and triplet-born lamb heat production at 24–36 h old and performance from birth until lactation day 94 (L94). Twin- (n=40) and triplet-bearing (n=28) ewes were grazed on a 60 mm sward height from day 70 of pregnancy (P70) until L94. From P100, half of the ewes from each litter size were offered 400 g/ewe/day of concentrate sheep pellets. Ewe liveweight and body condition were recorded on P50, 100, 130, 135 and 140. Ewe blood samples were also collected on P130, 135 and 140, and ewe herbage intake was estimated from P133–136 using the n-alkane method. Lamb measurements included liveweight and body size at birth, production of heat using indirect open-circuit calorimetry at 24–36 h old and liveweight at L94. Blood samples were also collected from lambs at 24–36 h old and directly before and after calorimetry measurements. While estimates of ewe herbage intake suggested that substitution of herbage for concentrate did not occur, offering concentrate supplement failed to improve ewe liveweight gain, or birth weight of lambs. Offering concentrate supplement, however, did have a positive effect (P<0·05) on the maximal amount of heat a triplet-born lamb can produce on a per kg of body weight basis (concentrate 21±1·3 W/kg, non-concentrate 17±0·6 W/kg). It also had a positive effect (P<0·05) on lamb square-root-transformed plasma gamma-glutamyl transferase (GGT) concentrations, an indicator of colostrum uptake (concentrate 46±3·1 U/l, non-concentrate 38±2·9 U/l). Irrespective of lamb birth rank, offering concentrate supplement had a positive effect (P<0·01) on liveweight gain per day from birth until L94 (concentrate 261±5·7 g/day, non-concentrate 239±5·8 g/day), although there was no effect on the total weight of lamb reared/ewe. Supplementation with concentrate resulted in triplet-born lambs that produced more heat which may have positive effects on the ability of the newborn lamb to deal with cold stress and potentially its survival. Offering concentrate supplement also produced greater lamb growth in twin- and triplet-born lambs.

Some meat retailers have introduced a trade embargo on fat lambs sold through livestock markets on the grounds that welfare standards associated with live auction markets are said to be worse than standards associated with direct sale to abattoirs. The current study examined the handling difficulties and welfare standards at 24 UK livestock markets. Comparisons were made according to class of animal (store, fat, breeding animals, etc.) and throughput of the market: <100 livestock units (LU) per week, 100–300 LU per week and >300 LU per week. Handling problems examined included refusal to move, balking, slips, falls, impacts, isolation leading to apparent distress, confusion while loading onto vehicles and inappropriate handling such as wool pulling. The overall prevalence of each handling problem was low (usually <0·05 of the sheep). The most common difficulties were impacts, slips and falls when grading fat lambs, and confusion or refusal to load onto the vehicles after the sale in ewes. Store lambs were generally easier to handle than fat lambs. They were less prone to refusing to move, balking, impacts, slips and falls. In fat lambs, slips and falls during grading were more common at small markets, while at larger markets there were more impacts, slips and falls during selling. Confusion during loading onto vehicles after the sale was more common in breeding ewes and rams, and at small markets. Projections in the corridors that were considered to be potential bruising or impact points were found in 0·33 of the markets and 0·71 did not have a way of ensuring that legs could not get trapped between gates and gateposts if sheep attempted to jump out of a holding pen. In most other respects the prevalence of problems with the facilities and during handling was low and it was concluded that a trade embargo on selling fat lambs in markets might not be justified.

In previous work, administration of a commercial tannin preparation, quebracho, as oral drench was shown to reduce significantly faecal egg counts (FEC) and worm burdens of temperate sheep with experimental Haemonchus contortus infection. In the current work carried out in Morogoro, Tanzania, three separate animal trials were carried out to investigate the effect of drenches of wattle tannin (WT), a similar tannin preparation that is readily available in the tropics, on nematodes of tropical goats and sheep. In the first trial, 36 young Small East African (SEA) goats were experimentally infected with a single dose of mixed nematode larvae and FEC were monitored regularly. On day 30 post-infection (p.i.), the animals were blocked on the basis of their FEC and randomly assigned into three equal groups (n=12). For 3 consecutive days, two groups received low and high doses of drench at a rate of 1·2 and 2·4 g WT/kg bodyweight, respectively, whereas the third group received a placebo drench (i.e. water). All goats were humanely slaughtered on day 42 p.i. and their worm burdens were assessed. Neither FEC nor worm burdens were significantly reduced by the administration of the low or high dose of WT. The second trial had an identical design but two groups (n=14) of growing Black Head Persian (BHP) sheep were used instead. One group received the drench at 1·5 g WT/kg body wt for 3 consecutive days, whereas the other group received a placebo. Unlike in goats, worm burdens and FEC were significantly reduced (P<0·001) by the drench administration. In the third trial, the effect of WT drench against a naturally acquired nematode infestation in a flock of 34 BHP sheep was determined. FEC were examined three times in a 2-week period and the egg counts were used to block the sheep before being randomly assigned into two groups (n=17). The treated group received the drench at 1·0 g WT/kg bodyweight for 3 consecutive days, while the remaining half was given a placebo. The two groups continued to graze together as FEC were being monitored. Results indicated a significant (P<0·001) reduction in egg counts, which remained low for at least 3 weeks after the drench. The current study demonstrated that the WT drench had significant anthelmintic activity against important nematodes in sheep but not in goats, suggesting an existence of species differences between the two hosts. It was concluded that WT drenches could be used in combination with other worm control strategies to reduce or control nematode infections, at least in sheep.

Dilution of [1-13C]leucine (Leu) and open-circuit calorimetry were used to determine the effects of diet and cold exposure on rates of plasma Leu turnover, Leu oxidation, and whole body protein synthesis (WBPS) in sheep. The experiment was designed as a crossover design for two 23-day periods. Six adult sheep were assigned to two dietary treatments, medium (Me-diet) and high (Hi-diet) intake, and were fed either 515 or 830 kJ/kg BW0·75 per day of metabolizable energy intake, respectively. The temperature in the chamber was changed from a thermoneutral environment (23°C) to a cold environment (2–4°C) for 5 days (the 18th to 23rd day of the experiment). Turnover rate of both plasma Leu and WBPS were greater (P<0·01) for the Hi-diet compared with the Me-diet and increased (P<0·01) during cold exposure. Leucine oxidation rate was numerically greater (P=0·10) for the Hi-diet compared with the Me-diet and increased (P=0·03) during cold exposure. No significant diet×environment interaction was detected in the rates of plasma Leu turnover, Leu oxidation or WBPS. It is concluded that plasma Leu kinetics and WBPS were influenced by intake level and increased during cold exposure, but the responses to cold exposure were not modified by intake level in sheep under the conditions of the present experiment.