The badger culling component of the cattle tuberculosis (TB) eradication scheme has been controversial from the outset. Despite the apparent complexity of the issue, and ever expanding literature, it is perhaps worth highlighting several basic key aspects in need of an urgent reappraisal.

Abnormally low concentrations of morphine in capsules of poppy (Papaver somniferum L.) in the 1970–1 season were associated with heavy fungal colonization. The effect of fungal colonization on the morphine production of capsules was later studied in a series of field, glasshouse and in vitroexperiments.

In a field experiment morphine concentration of severely colonized (> 30% surface cover) intact capsules was 20% less (P <0·01) than slightly colonized (< 10% surface cover) capsules. Colonization of these field-grown capsules was generally localized in the top half and the morphine concentration of the top half was about 20% less than the bottom half for all colonization categories. In contrast, glasshouse-grown capsules were free of fungal colonization and the top and bottom halves had similar morphine concentrations.

In a field experiment studying the effect of fungicides, 2 kg benomyl (50% a.i.) + 2 kg mancozeb (80% a.i.)/ha were applied as a spray at 10-day intervals from flowering till 1 month after commercial harvest and plants were harvested at weekly intervals from 10 days after full bloom. The mean dry-matter yield of sprayed capsules was 11% greater (P <0·01) than non-sprayed with a similar trend for morphine concentration and morphine yield. In addition, the sprayed treatment significantly reduced the area covered by sporulating lesions on the surface of the capsule after dry maturity. This superficial fungal cover had a NNE orientation in both sprayed and non-sprayed capsules.

In an in vitroexperiment using capsules from the field fungicide study, fungi were isolated from the interior of green capsule wall tissue as early as 17 days after flowering. Colonization increased with successive harvests and culturing of fungi from the interior of capsule wall tissue showed the presence of fungi in both sprayed and non-sprayed capsules with no difference in the degree of colonization.

Two of the major fungi isolated from the field experiment were identified as Dendryphion penidllatum (Corda) Fr. and Alternaria alternata (Fr.) Keissler and the individual effect of these was assessed in an in vitro experiment using ground capsule material. D. penidllatuvi and A. alternata reduced the morphine concentration of ground capsules in 24 days to 7 and 11% respectively of non-inoculated controls.

The mean total yield and mean fresh weight of seven swede varieties and their F1 hybrids was increased primarily by nitrogen and also by phosphorus fertilizer. There was no evidence of genotype × environment interaction for characters concerned with yield except for dry-matter content where two varieties, Best-of-All and Reform, were less stable to fertility environments than the others. Heterosis was common amongst F1 hybrids and this suggests their use in swede improvement: the inheritance pattern of root weight showed overdominance, shoot weight showed partial dominance and drymatter content showed additivity, with no evidence of gene interaction. Segregation for root fresh weight and dry-matter content occurred in F2 populations and although an overall negative correlation was found there was evidence that progeny from certain crosses gave reasonable prospects of combining both characters.

Comparisons of the effects of harvesting sugar-beet seed by the traditional method of tripodding with barn drying, swathing followed by threshing with a pick-up combine or desiccation with diquat followed by direct combine harvesting showed that there were no consistent or large effects on seed yield, germination, monogermity or size distribution. Thus the best method will be the one which is easiest and/or cheapest, which at present is swathing followed by pick-up combine threshing.

Sprays of NAA or 2,4,5-T at 10 or 100 mg a.i./l water before or after flowering had no effect on seed yield or germination and efforts to restrict the loss by shedding of large viable seed failed. Neither chemical decreased germination percentage by setting parthenocarpic seed. Attempts were made to dwarf the 2 m high seed crop to make it suitable for direct combine harvesting. Daminozide sprayed at 1000, 5000 or 10000 mg a.i./l water before or after the winter did not affect plant height, seed yield, germination, monogermity or size distribution. Chlormequat chloride applied similarly dwarfed plants by up to 18% but this was not enough to give a crop less than 1 m high suitable for direct combine harvesting. It did not affect seed yield, germination, monogermity or size distribution. Ethephon sprayed at 10, 100 or 1000 mg a.i./l water when plants were bolting had no detected effects. Chlorflurecolmethyl was sprayed at 10 or 100 before bolting or 1, 10 or 100 mg a.i./l water afterwards. Plants sprayed with the 100 mg/1 solution were dwarfed to less than 1 m high but the treatment was unsuccessful because it greatly reduced seed yield and germination; monogermity was not affected but a much greater proportion of seed fell into the small size grades.

Bovine spermatozoa aged for 6–7 days at room temperatures (18–30° C.) in a coconut milk extender retained their fertilizing capacity. However, their fertilizing ability appeared to be impaired by environmental hazards in the form of oxygen damage, exposure to visible light, and temperature shock. Protective measures developed and used in the preparation and in the storage of the sperm suspensions to minimize premature loss of sperm function involved the addition of catalase and egg yolk to the extender and the maintenance of cell suspensions in the dark in vials containing a minimal air space. The experimental evidence obtained with this improved coconut milk extender established its ability to support and sustain the fertilizing capacity of bovine sperm for 6–7 days at room temperatures at a level comparable to the fertilizing capacity of refrigerated sperm in milk-glycerol or egg yolk-citrate-glycine extenders. The economic importance of this room temperature diluent is suggested by the fact that it eliminates the costly refrigeration required to maintain stored and shipped bovine semen at 5° C.

Coconut milk extender modified by the addition of 5% egg yolk also proved to be a satisfactory storage medium for sperm at low temperatures. It was found to be superior to both egg yolk-citrate and skim-milk extenders in conserving motility at 5° C. The fertilizing capacity of Ayrshire and Brown Swiss sperm stored at 5° C. in coconut milk extender which contained 15% coconut milk and 5% egg yolk compared favourably with the fertilizing capacity reported for sperm stored at 5° C. in other more widely used diluents. The number of motile sperm recovered from this extender after freezing to −79° C. was comparable to the number of motile sperm recovered from the egg yolk-citrate and skim-milk test diluents. The results of this study indicate that coconut milk extender is a versatile, easily prepared medium which can be used to preserve functional sperm over a wide temperature range.

The present experiment was conducted to quantify the net fluxes of both free and peptide amino acids across the mesenteric and stomach portions of the portal-drained viscera (PDV) of three yak cows (172·3±18·6 kg, BW) fed a straw-concentrate diet at maintenance level. Yaks had been fitted with sampling catheters in the portal vein, mesenteric artery and mesenteric vein prior to its convergence with the gastrosplenic vein. Blood flow was determined by measuring the dilution of para-aminohippurate (PAH) infused constantly into a distal mesenteric vein. Amino acids in the deproteinized plasma were analysed before and after acid hydrolysis. The increased amino acids after acid hydrolysis were considered as peptide-bound amino acids (PAA). The fluxes of free amino acids (FAA) and PAA across PDV and mesenteric-drained viscera (MDV) were calculated as the product of venoarterial differences and plasma flow. Flux across the stomach viscera (SDV) was calculated as the difference between portal and mesenteric fluxes. Portal blood flow was 389 l/h or 2·32 l/h kg BW, of which 37% was contributed by the mesenteric vein. There was net appearance of a large quantity of PAA across PDV, which accounted for 92% of the total nonprotein amino acid flux. Net release of PAA and FAA in SDV accounted for 78% and 42% of the net release in PDV, respectively. These results suggest that in yaks, peptide possibly is the primary form of amino acid absorption, and that the stomach area probably is the major site of peptide absorption.

Although salt injury in plants is due to both osmotic and specific ion effects, little is known about the reaction of rice plants to salinity under increasing sodium adsorption ratios (SAR) in the growth medium. Therefore, a glasshouse experiment was conducted to study the effect of four levels of salt concentration (20, 40, 60 and 80 m-equiv/1 with respect to the sum of Na+, Ca2+ and Mg2+) and four levels of SAR (2, 25, 50 and 75) on growth and mineral composition of rice cvs IR 2153-26-3 and IR 26. The results show that as salt concentration increased, dry-matter yield and percentage water content of shoots decreased regardless of the variety. The rate of decline with salinity was most pronounced under low SAR and in the salt-sensitive variety IR 26. With increase in SAR, the yield, percentage water content and concentrations of Ca, Mg, and K in shoots and roots decreased, but the effects were more marked at the lowest salt concentration and in IR 26. Variety IR 2153-26-3 showed greater tolerance, maintaining a higher concentration of Ca and higher Ca/Na and K/Na ratios and a lower concentration of Na and Cl in the tops compared with IR 26.

The degree of salt injury in rice seems to depend not only on salt concentration but also on SAR in the growth medium whilst salt tolerance is associated with tolerance for both high salt concentration and high SAR. Therefore, in studies on screening rice varieties for salt and sodium tolerance, the interactive effects of SAR and salinity must be considered so as to ensure greater adaptability by the varieties recommended for salt-affected soils.

Previous studies on the Scottish Blackface breed have shown that ovulation rate and lambing performance are closely related to body condition at mating. Ovulation rates greater than two were achieved from ewes in good body condition (grade 3·0 on a scoring system described by Russel, Doney & Gunn, 1969) and this performance was not affected by condition either rising or falling to the pre-determined grade at mating (Gunn, Doney & Russel, 1969). Ewes in lower body condition at mating (described by grades 1·5, 2·0 and 2·5) were found to have correspondingly lower mean ovulation rates (Gunn et al. 1969; R. G. Gunn and J. M. Doney, unpublished). In these, and other experiments giving similar results, the experimentally controlled changes in nutrition and hence body condition were imposed for only a few weeks prior to mating, i.e. during late October and November. However, in traditional hill grazing systems, ewe recovery may be expected earlier and may be followed by a considerably longer period of live-weight and condition maintenance. In situations where some degree of grazing control can be used to modify the nutrient intake cycle, it is important to know if food consumption and subsequent reproductive performance can be influenced by the long-term pattern of recovery.

A Recent statistical survey of the records of premium stallions by Sanders (1) draws attention to the fact that the breeding efficiency of the horse is much below that of the other domesticated animals and that it has apparently declined within recent years. For example, between 1887 and 1889 the average number of mares served by Light Horse stallions and which produced foals was about 59 per cent, of the total mares served. Between 1904 and 1910 this figure had fallen to about 56 per cent, and at the present time is not much above 50 per cent. While this decline may in part be due to the record of infertile services being kept more strictly now than formerly, and perhaps also to the more rigorous conditions to which travelling stallions are subjected, the figures are sufficient to indicate that much loss is actually occasioned by low breeding efficiency and also that there might be considerable improvement on the present standard.

The pollination requirements of the white lupin cultivar Vladimir were investigated in a glasshouse. Five treatments were compared in which the flowers of each plant were (i) left to autopollinate, (ii) shaken, (iii) tripped, (iv) self pollinated or (v) cross pollinated. Pollination treatments had no effect on the numbers of flowers, pods or seeds or weight of seed produced by the plants but did slightly shorten the duration of flowering, the effect being greatest when flowers were tripped or cross pollinated and least when they were shaken or self pollinated.

The proportion of flowers that developed into pods differed with raceme, with secondaries producing more than tertiaries > primaries > quaternaries; the number of seeds per pod differed in the same order, but mean single-seed weight decreased on successive racemes. However, pollination treatments had no effect on the distribution of flowers, pods or seeds on the plant.

This crop species is clearly highly self fertile and self pollinating and likely to yield well without insect pollination.

1. Three hays of Coastal Bermuda (Oynodon dactylon) grass and three hays of Pangola grass (Digitaria decumbens) from grasses cut at different stages of maturity were used for the determination of digestibility coefficients, voluntary intake, rate of passage through the gut, production of total and individual volatile fatty acids, total counts of bacteria determined microscopically and examination of bacterial types present using Gram-stained smears. The animals used were individually housed sheep.

2. The hays of Coastal Bermuda were significantly superior to those of Pangola from the point of view of digestibility. Significant differences did not exist within grasses.

3. The hays of Coastal Bermuda were superior to those of Pangola from the point of view of intake although this was not significant.

4. No relation was evident between digestibility of the various hays and rate of passage through the digestive tract; it was concluded that intake was not limited by rate of passage through the gut.

A surgical preparation was developed to measure uptake of amino acids from the small intestine into the cranial mesenteric vein (CMV) of lambs. Results from this preparation were compared with those from the traditional hepatic portal vein (PV) preparation in the same lambs. Necropsy revealed that, in contrast to the PV preparation which included all portal-drained viscera, the CMV preparation drained primarily small intestine (0·84–0·92 small intestinal mass). The CMV preparation contributed 0·238 of blood flow from and 0·307 of oxygen consumption by the PV preparation. Venous-arterial differences for alpha-amino nitrogen (AAN), phenylalanine (Phe) and tyrosine (Tyr) were three- to fourfold greater in the CMV than in the PV preparation, indicating that the CMV preparation is more sensitive for measuring amino acid uptake. The ratio CMV/PV for uptake of AAN was 0·61 (P< 0·001), but this ratio was much closer to unity (mean 0·84) for Phe and Tyr. Since the CMV preparation drains primarily the small intestine, through which all amino acid absorption occurs, it should prove to be extremely valuable for studying absorption from and metabolism within this organ using a combination of arteriovenous and isotopic tracer techniques.

Sectional and intrasectional variations in muscle fibre diameter over a restricted axial range were examined in seven bovine muscles from foetuses, calves and steers. Significant sectional variations were found in four muscles, while two muscles showed significant intrasectional variations. The results indicate that sampling sites require accurate definition in comparative studies of muscle fibre diameter.

Two extensor muscles of the foreleg, m. extensor carpi radialis and m. extensor digitorum communis showed neither sectional nor intrasectional variation in muscle fibre diameter and appear to be more satisfactory muscles for use in muscle fibre growth studies than m. longissimus thoracis et lumborum.

A comparison of mean muscle fibre diameter in 60 pairs of contralateral muscles showed that there were no significant differences in 52 of the muscle pairs.

The winter-heading cauliflower varieties St Thomas, St Gwithian, St Agnes, Janavon, St Hilary, St Buryan, BB74605, St David and St Keverne were grown at Trefloyne, Tenby for 3 years from 1977 to 1980. Plants of all varieties were sampled periodically to determine the rate of curd expansion, the final number of leaves, the time of curd initiation, and the distribution of dry matter within the plant.

The patterns of development of leaf area were similar in all varieties. Dry-matter distribution was similar for all varieties except for root growth; later-maturing varieties had a greater dry weight of root and a higher proportion of the total dry matter as root, than early varieties. Early rates of curd growth declined with later-maturing varieties and it is suggested that there may be a relationship between the time of curd initiation, root growth and the rate of curd growth.

The mean total number of leaves formed before curd initiation varied from 49 to 102 depending on the variety and year. The earliest varieties St Thomas and St Gwithian took co. 120 days to reach 50% curd initiation and matured in 6–7 months from sowing while the late variety St Keverne took over 200 days to reach 50% initiation and more than 11 months to mature. The time interval between 50% initiation and 50% maturity increased with later-maturing varieties but on the basis of accumulated day degrees > 6 °C it declined with later varieties. The latter also matured more uniformly than earlier varieties when using an accumulated day-degree scale > 6 °C as a time scale.

The results suggest that the low temperature threshold below which curd induction occurs may vary with variety. There was also evidence that the base temperature for curd growth is lower with later-maturing varieties.

A significant genotype–environment interaction can limit gains in selecting superior genotypes since the best genotype in one locality may not be the best one in another locality. The efficiency of indirect selection is related to the heritability of the trait and to the genetic correlation between localities. Since a major objective of Eragrostis curvula (lovegrass) breeding programmes in Argentina is to select superior genotypes from new cultivar introductions, research on the relative effectiveness of direct and indirect selection is necessary in order to identify localities under which the efficiency of indirect selection could be maximized. To do this, experiments using a set of 18 hybrids were carried out in three localities from the semi-arid region of Argentina. Aerial biomass yield, leaf length, crown diameter, panicle number and panicle length were measured and an analysis of variance and covariance were performed. The high genetic correlation obtained suggests that the genetic mechanisms involved in the expression of these traits would be the same, or at least very similar, in Río Cuarto, Villa Mercedes and Bahía Blanca environments where the hybrids showed a stable performance. In general, the heritability obtained was higher in Villa Mercedes and Bahía Blanca than in Río Cuarto. For a given selection intensity the expected correlated response in Villa Mercedes and Bahía Blanca to indirect selection was compared with the expected gain with direct response to selection in Río Cuarto. For dry matter yield, indirect selection in Bahía Blanca did not differ from selection done in Río Cuarto (−3%). However, for performance in Villa Mercedes indirect selection was shown to be less efficient (−29%). For the other traits considered, indirect selection was variable and less efficient, ranging from −18 to −34%. The estimated decrease in efficiency of selection for all the traits considered in the locality of Río Cuarto was higher than in the other localities, suggesting that this place was not a good choice for carrying out indirect selection. Conversely, genetic progress would be faster if selection was carried out in Villa Mercedes, because the evaluations provide higher and more accurate estimates of the heritabilities than in the other localities.

The success of Linum usitatissimum as a commercial crop depends on its value for seed/oil (linseed) and/or fibre/straw production (flax). In the present study we evaluated nine linseed × linseed and two linseed × flax crosses for their potential to produce recombinant inbred lines (RILs) that give higher yields for dual-purpose (high seed–high fibre) traits. Analysis of the early generations indicated that while all crosses segregated for seed weight, straw weight, capsule weight and total plant weight, some crosses lacked the necessary genetic diversity to produce superior RILs. The performance of F3 families supported this conclusion as only two crosses were identified which had adequate potential to produce improved RILs with high seed and straw/fibre yields. The four most heterotic crosses identified in a previous experiment showed little potential for transgressive recombinants, although the best of these RILs would make better dual-purpose varieties compared to existing cultivars. Genotypic correlations were generally positive and should increase the chances of extracting RILs producing both high seed/oil and straw/fibre yields.

Thirty-two pregnant ewes (Saudi breeds) selected during 1998 and 1999, were studied throughout the whole gestational length and around parturition. Concentrations (mean±S.E.) of plasma progesterone (3·9±0·28 ng/ml), oestradiol-17β (20·5±2·33 pg/ml) and cortisol (4·8±0·58 ng/ml) remained fairly constant throughout the early stages of pregnancy. Characteristic changes in these steroids were evident during the prepartal period involving a steady decrease in plasma progesterone beginning 8 days before parturition; a remarkably consistent increase in oestradiol-17β 4–6 days prior to delivery, peaking in excess of 250 pg/ml at the birth day; and a fivefold increase to 23·7±2·12 ng/ml in plasma cortisol 2 days preceding delivery, showing a large increase during the day of lambing. The timing of the marked reduction in the platelet count and the coagulation screening tests including prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT), during the prepartal period, were significantly correlated with the temporal changes in the circulating steroid hormone concentrations. The results suggest that the characteristic prepartal hormonal changes might provide the basis for shifting the fairly balanced coagulable state throughout gestational periods to a mild to moderate degree of hypercoagulability during parturition which is needed to limit the possible intra- and post-partum uterine haemorrhage.

1. The point at which continued development of a seed no longer depends upon attachment of the culm to the root system can be termed rootindependence.

2. Serially harvested inflorescences of Lolium temidentum L. were maintained in a glasshouse under the same environmental conditions as standing material. Samples for analysis were taken from harvests and standing material at 2 days intervals to compare chemical changes occurring in seed on standing and severed culms. Analyses for total soluble carbohydrate (T.S.C.) were performed on a single seed basis.

3. Harvests made before the seed T.S.C. maximum resulted in oscillating changes in endosperm free sugar content and these caryopses tended to stabilize at an excessively high value. All later harvests resulted in seed with a final T.S.C. level within 1% of that present in normally matured seed

4. 14C-Sucrose uptake studies showed that tho endosperm T.S.C. requirement was high prior to the seed T.S.C. maximum but that it was very low during the second half of the maturation sequence. It is considered that during this period sugar is only translocated to make good respiratory losses.

The effects of different plant arrangements (conventional single rows v. paired rows at a standard density of 55–67 thousand three-bud setts/ha) with different intercropped green manuring strategies with Sesbania aculeata (none v. ploughed in after 4 and 6 weeks) and with different amounts of nitrogen (N) fertilizers (0,75 and 150kg/ha) were studied in sugarcane crops planted after wheat or mustard and in its first ratoon. The yield of millable cane from the planted sugarcane was not affected by intercropped green manuring or plant arrangement but was increased by fertilizer N after both wheat and mustard. The residues from the green manuring and fertilizer N both increased the yield of the following crop of ratoon sugarcane by 9–10% with the residues increasing the numbers and length of millable canes and the fertilizer N the number, girth and weight of the millable canes. None of the treatments affected the quality of cane juice in either the planted cane or the ratoon crop. Residues from the green manures and the N fertilizer treatments increased the organic carbon content and available N in the soils.

In calorimetric work the ideal experimental conditions are that all factors capable of influencing metabolism, except the one whose influence is the object of investigation, should be made constant or otherwise accounted for. It was while striving to attain such conditions that the necessity for this study arose.

During an investigation into the effect of food ingestion on the basal metabolism of the goat by the method of indirect calorimetry described by Orr and Magee(1) it was deemed inadvisable to ignore the diurnal variations in external temperature, and, consequently, it was decided to submit the animal to varying changes of external temperature and to determine their effect upon its basal metabolism. It was the special objective of the experiments to ascertain the critical temperature of the goat or the temperature at which the vital processes of the animal are most economically maintained.