Two experiments were conducted to examine the effects of supplementation of a control diet of barley grain and barley straw containing 4 mg copper (Cu)/kg dry matter (D.M.) either with 5 mg molybdenum (Mo)/kg D.M. or with 500 or 800 mg iron (Fe)/kg D.M. on puberty, fertility and oestrous cycles of cattle. Puberty occurred normally in control, Fesupplemented and control animals on a restricted intake whereas it was delayed by 12 and 8 weeks respectively by Mo supplementation. This effect of Mo was not due to the low Cu status since this was equally low in the Fe-supplemented animals, nor was it due to the reduced growth rate since puberty occurred normally in control animals that had a similar live-weight gain. A significant reduction in the pulsatile release of luteinizing hormone was observed within 11 weeks of the Mo supplementation and before any of the other clinical signs were evident, suggesting that Mo may be affecting puberty by altering the release of luteinizing hormone either directly or indirectly.

Mo supplementation significantly reduced the percentage conception rate to 12–33% compared with 57–80% in control and Fe-supplemented animals. This effect was not dependent on the rate of live-weight gain which was standardized across the different treatments at approximately 0·6 kg/day. Within 12 weeks of the replacement of dietary Fe by Mo a lower conception rate occurred; replacing dietary Mo by Fe led to a normal conception rate within 12 weeks without any accompanying changes in Cu status or in the rate of live-weight gain. The plasma Mo concentrations, however, changed significantly during these alterations in dietary supplementation. The pre-ovulatory peak height of luteinizing hormone was significantly lower in animals on the Mo-supplemented diet compared with control and Fe-supplemented animals, but the administration of LHRH did not alter the conception rate.

More Mo-supplemented animals failed to ovulate following prostaglandin induced synchronization in comparison with the other treatments, and by the 84th week a significantly greater number of Mo-supplemented animals (12/18) had become anoestrous compared with the other groups (2/30). Cu repletion of these anoestrous Mo animals for a period of 20 weeks did not result in resumption of normal oestrous cycles, but ovulation and oestrus were induced by progesterone and LHRH treatment. Results in the latter part of the study indicated that Mo caused superovulation.

These data show that Mo supplementation delayed the onset of puberty, decreased the conception rate and caused anovulation and anoestrus in cattle without accompanying changes in Cu status or in live-weight gain. It is suggested that these effects of Mo are associated with a decreased release of luteinizing hormone that might be due to an altered ovarian steroid secretion.

In a previous paper (1) some of the factors which control fertility in domestic animals were discussed. These for purposes of clearness in investigation were divided into two groups: (1) The factors which control the number of eggs shed; and (2) The factors which control the number of eggs which develop to reach birth size. By this means the way in which the various factors which affect fertility could be determined, for example, it was shown that the effect of age on fertility, the literature of which has been reviewed by Harris (2), is due to the number of eggs shed at each oestrus period. Young sows examined had on the average 14 corpora lutea in the ovaries while old sows had 20 corpora lutea.

The Lolium-Festuca complex of related species provides a wide range of variation for the development of versatile grasses adapted to meet the changing requirements of livestock farming. Various approaches have been used in order to harness the full potential of this variation. Tetraploid hybrids between the two ryegrass species L. perenne and L. multiflorum have resulted in stable and successful commercial varieties. Hybrids between more distantly related ryegrass and fescue species have demonstrated useful combinations of traits from both parents. Chromosome doubling is necessary in these hybrids to restore fertility in synthetic amphiploids. However, genetic instability can still be a problem and research is in progress to obtain tighter control of chromosome pairing. An alternative approach is to introduce a few specific traits from fescues into ryegrasses, or vice versa, using introgressive breeding procedures. This review outlines the progress already achieved in exploiting the ryegrass–fescue complex by using these various approaches and assesses the potential of hybrid derivatives.

Phenological models are considered key tools for the short-term planning of viticultural activities and long-term impact assessment of climate change. In the present study, statistical phenological models were developed for budburst (BUD), flowering (FLO) and veraison (VER) of 16 grapevine varieties (autochthonous and international) from the Portuguese wine-making regions of Douro, Lisbon and Vinhos Verdes. For model calibration, monthly averages of daily minimum (Tmin), maximum (Tmax) and mean (Tmean) temperatures were selected as potential regressors by a stepwise methodology. Significant predictors included Tmin in January–February–March for BUD, Tmax in March–April for FLO, and Tmin, Tmax and Tmean in March–July for VER. Developed models showed a high degree of accuracy after validation, representing 0·71 of total variance for BUD, 0·83 for FLO and 0·78 for VER. Model errors were in most cases < 5 days, outperforming classic growing degree-day models, including models based on optimized temperature thresholds for each variety. Applied to the future scenarios RCP4·5/8·5, projections indicate earlier phenophase onset and shorter interphases for all varieties. These changes may bring significant challenges to the Portuguese wine-making sector, highlighting the need for suitable adaptation/mitigation strategies, to ensure its future sustainability.

An algorithm to fit boundary lines, using cubic smoothing splines, was written and used to identify yield responses to changes in soil properties. This method involves fitting a curve that represents the maximum yield response to each predictor value, which represents the yield potential at each soil property value. Boundary-line yield responses to individual soil properties were found to differ from responses found by fitting curves through the data scatter. The effects of correlated variables appeared to be lessened using the boundary line approach. Multivariate boundary-line models, based on the Law of the Minimum, were found to be useful for the identification of site-specific causes of yield variation and yield potentials. The boundary line was found to be a useful complement to more traditional data analysis techniques.

Lotus pedunculatus was grown under high fertility conditions and its nutritive value was determined in a feeding trial with sheep at Palmerston North, New Zealand in 1989. The condensed tannins (CT) accounted for 5·5 % of lotus dry matter (DM) and its effect on digestion was evaluated by giving an intraruminal infusion of polyethylene glycol (PEG) to six of the sheep (PEG group). PEG preferentially binds with CT so that the lotus becomes essentially CT-free.

The experiment was carried out with 14 sheep (six PEG and eight ‘Tannin’) held in metabolism crates indoors and given freshly cut lotus hourly, for 32 days. This paper presents data relating to carbohydrate and mineral digestion, together with aspects of rumen function.

Digestibility of lotus DM was 68%, and the digestibility of fibre was not affected by CT. Infusion of PEG increased rumen concentrations of NH3 and volatile fatty acids (P < 0·001) but effects on molar ratios of VFA were inconsistent with time. CT reduced rumen degradation and absorption of sulphur and increased net absorption of both phosphorus and zinc, but other effects on mineral digestion were small.

Although the lotus was offered at c. 90% of ad libitum, intakes of the tannin sheep began to decline after c. 15 days of feeding and were c. 12% lower than those of the PEG sheep at the end of the trial (P < 0·05). At slaughter, rumen pool sizes were similar for the two treatments but the Tannin sheep had a lower fractional outflow rate, which suggests a slower rate of digestion in the rumen. Growth rate and wool production were similar for sheep on both treatments. It is concluded that the CT in Lotus pedunculatus grown under high fertility conditions had little effect on fibre and mineral digestion but the depression in DM intake reduced its nutritive value for sheep.

Sheep meat is characterized as being high in saturated fatty acids and low in polyunsaturated fatty acids (PUFA), attributes that are regarded as being disadvantageous within the human diet. Despite fresh forage being a particularly rich source of 18:3n−3 and vegetable oils being high in 18:2n−6 and 18:3n−3, the process of biohydrogenation in the rumen generally results in proportionally less than 0·1 of these essential dietary fatty acids (FA) reaching the small intestine. Increases in muscle content of 18:3n−3 of 1–2-fold have been achieved by supplementation with oil, or oilseeds, whilst increases of 1–3-fold have been obtained from grazing grass compared with concentrates, but in general the polyunsaturated to saturated FA ratio (P:S) in sheep meat has remained low at approximately 0·2–0·3. Substantial improvements in the P:S ratio of up to 0·57 and increases in muscle and adipose tissue levels of 18:3n−3 of up to 4 g/100 g FA can be obtained, but rely on protecting dietary PUFA from biohydrogenation. Additionally, increasing tissue supply of 18:3n−3 will result in only a small improvement in muscle concentration of the nutritionally beneficial 20:5n−3 and 22:6n−3, with meaningful increases relying on a dietary supply of these very-long-chain PUFA. An alternative strategy to improve the human health attributes of sheep meat is to decrease tissue levels of 18:0 by increasing the activity of stearoyl-CoA desaturase (SCD), although the response is often relatively small. Despite the apparent negative impact of ruminal metabolism on muscle FA content, the process of biohydrogenation is often incomplete and several of the intermediaries can have positive effects on human health. Within these intermediaries, future increases in tissue content of cis-9, trans-11 conjugated linoleic acid (CLA) may be obtained by increasing tissue supply directly, although a greater response may be obtained by maximizing tissue supply of trans-11 18:1 and elevating the action of SCD. Production of a FA profile in sheep meat that is higher in PUFA, particularly the advantageous very-long-chain PUFA, and with flavour and eating characteristics that meet specific market preferences, is a suitable area for research.

1. Controlled self- and cross-pollinations were performed on field bean plants. It was found that while manipulation of the flower stimulated seed setting, both self- and cross-pollination were equally effective.

2. Estimations of pollen germination on artificial medium, to which had been added extracts of styles or ovaries from the same or a different plant, gave some slight evidence of a specific inhibition by ‘self’ extracts. No analogous effect was detected on pollen tube growth.

3. Experiments in which the style was cut at varying intervals after pollination detected no difference between self- and foreign pollen in rate of growth through the style. Pollen placed on stigmas of immature flowers began growth at once although the fertility achieved was less than when mature flowers were used.

4. The composition of seed from mixed self- and cross-pollination was examined. Early application of foreign pollen increased the proportion of crossfertilization but the results were similar in hybrids and inbreds.

5. Flower manipulation was more effective in stimulating seed setting than shaking the plants. Spraying with hormone solution was ineffective.

6. It was found that plants varied in their capacity to set seed without flower manipulation (autofertility). Hybrid plants were more autofertile than plants from inbred lines.

7. X-ray pictures of unopened flowers suggested that the pollen may be more abundant and less diffuse in hybrids than in inbreds.

8. The expression of autofertility was affected by many genetic factors.

9. Seed produced by open pollination of F1 hybrids contained a much higher proportion derived from self-pollination than did seed from inbred plants grown in the same plot. Possible explanations for this difference, and some consequences for the population genetics of the species, are discussed.

1. A thermophilic organism which destroys cellulose at 65° C. has been isolated in pure culture.

2. The organism is motile, gram negative, forms spores in the swollen end, stains well with carbol fuchsin, poorly with methylene blue.

3. After growth on media without cellulose the organism is unable to ferment cellulose.

4. The range of fermentation is from 43° C. to 65° C. The organism lives at 38° C. and 72° C. but does not ferment at these temperatures.

5. The spores are very resistant to heat and withstand 115° C. for 35 minutes.

6. Heating the spores to 100° C. for 5 to 10 minutes causes an increased rate of germination.

7. Carbohydrates fermented: cellulose, starch, raffinose, sucrose, maltose, lactose, mannose, galactose, fructose, glucose, xylose and arabinose.

8. Organic nitrogen is necessary for the fermentation, and peptone is the best source.

9. The products from cellulose are: acetic acid, small amounts of butyric acid, ethyl alcohol, carbon dioxide and hydrogen. The amount of cellulose destroyed in a 1 to 5 per cent, suspension varies from 70 to 95 per cent. Of the cellulose destroyed, 50 to 55 per cent, is regained as acetic acid, 5 to 25 per cent. as ethyl alcohol and the rest as small amounts of butyric acid, carbon dioxide, hydrogen, and pigment. The pigment is a fatty substance soluble in ether.

When soil is partially sterilised, either by heat or by volatile antiseptics like carbou disulphide, toluene, etc., it becomes more productive and capable of yielding larger crops. The effect of heat was discovered incidentally about 25 years ago by the early soil bacteriologists; the action of carbon disulphide was first noticed somewhat later by a vine grower who had used it to kill phylloxera. Both cases have since been studied by several investigators, notably Koch and Hiltner and Störiner; a paper was also recently published by one of us in which it was shown that the property is a general one, holding for all the soils and volatile antiseptics examined and for all the plants, excepting those of the leguminous order. Thus when a soil had been heated to 95° C. it produced two, three, or sometimes four times as much crop as a portion of the soil which had not been heated, whilst treatment with volatile antiseptics led to an increase in crop varying between 20 and 50 per cent.

Data from experiments with spring wheat, variety Kolibri, were used to examine size gradients within the mature ear in relation to ear development. The greatest number of grains and florets per spikelet, and the heaviest grains, occurred in the lower-mid part of the ear. Within the spikelets in this region grain 2 > grain 1 > grain 3.

It is proposed that the timing and period of ear development and the number of spikelets can be described quantitatively in terms of (1) the rate of leaf initiation, (2) the number of leaves, (3) the rate of spikelet initiation and (4) the total number of primordia. Both leaf and spikelet initiation proceeded at more or less constant rates, but spikelet initiation was about three times as fast as leaf initiation. Differentiation of the spikelet primordia started at about the time the terminal spikelet was initiated, occurring first in the spikelets in lower-mid part of the ear. The rate of floret initiation was lower than that of spikelet initiation, but did not differ between spikelets. A maximum of nine florets per spikelet was formed and then, in all spikelets, some of the last-formed primordia died, leaving two to four potentially fertile florets.

Morphologically, primordia in the lower-mid part of the ear were always the most advanced. The more rapid development of the terminal primordia tended to synchronize events such as meiosis and anthesis, thus shortening the development period of the later formed florets. Changes in meristem size were such that both length and diameter were the greatest when the primordia of the lower-mid part of the ear were initiated.

The statistical model to describe primordium initiation and ear size is compared with other models describing primordium initiation rates. The analysis of ear development in quantitative terms is discussed in relation to analyses of ear development by morphological stages. A correlation between grain size and time of floret initiation is demonstrated and the significance of the size changes in the meristem is discussed.

The effect of maternal undernutrition between the 30th and 96th day of pregnancy on placental growth in single-bearing ewes was determined separately in two experiments in consecutive years (1986 and 1987) at Mount Derrimut Field Station, Deer Park, Australia. In the first experiment, placental growth measured on the 96th day of pregnancy was reduced (473 v. 596 g) by maternal undernutrition, while in the second, placental growth was increased (600 v. 496 g). Foetal weight and its linear dimensions on the 96th day of pregnancy were not significantly affected by maternal u dernutrition in either experiment. The only significant difference in the animals and experimental conditions between the two studies was the liveweight of the ewes at mating, which was c. 10 kg higher in the second experiment compared with the first (P < 0·01). Body condition score and the change in condition score during the respective nutritional treatments were not significantly different between the two experiments. The results suggest that maternal liveweight, possibly body reserves not quantifiable by condition score, protects and even enhances placental growth during a period of maternal undernutrition.

1. Fifty-one Scottish Blackface ewes were divided into three groups and individually fed throughout the latter half of pregnancy: (I) in excess of nutrient requirements, (II) to produce a uniformly moderate degree of undernourishment during the last 6 weeks of pregnancy, and (III) to produce a uniformly severe degree of undernourishment during the last 6 weeks of pregnancy,

2. The prescribed levels of undernourishment were maintained by weekly adjustments of feed intake based on plasma FFA levels (group II) and plasma ketone levels (group III). The use of the technique is discussed.

3. Undernourishment during the latter half of pregnancy reduced birth weights of single and twin lambs after adjustment for weight of the dams to the same extent. In the moderately undernourished ewes the reduction was approximately 10%, and, in the severely undernourished ewes, approximately 25%.

An experiment to measure the variation in the phenological and apical development ofwinter wheat (cv. Avalon) in England and Scotland is described. Ten sites which ranged from Aberdeen (57·2° N), the most northerly, to Newton Abbot (50·6° N), the most southerly, were included in the survey, and at each site seed was hand-sown in mid-September, October and November 1983. Developmental stages and sampling procedures were precisely defined to ensure uniformity in scoring by the observers at each site. Temperatures during the growing season were in line with the long-term means, though spring was cooler at all sites and summer warmer at most. The range of monthly-mean temperatures between sites was about the same as the difference between consecutive months. The method of analysis of development rates and durations was in terms of thermal time, modified by sensitivity to photoperiod and a vernalization requirement that slowed early development until a number of days of low temperatures had been experienced. In general, crops at northern sites developed more slowly than those in the south and particularly the south-west of England. There was less variation in the timing of apical stages for later sowings. Developmental rates responded linearly to temperature and photoperiod, with the base temperature increasing for later phases of development. The effect of photoperiod in modifying the rate of development was apparent for all developmental phases from emergence to anthesis, longer days accelerating development, but there was no effect on the duration of the grain-filling period. Vernalization exerted its effect solely within the phase from emergence to double ridge, and had a major influence on the variation between sites only for the first sowing.

Carbon footprinting is an increasingly important method of communicating the climate change impacts of food production to stakeholders. Few studies utilize empirical data collected from farms to calculate the carbon footprints of lamb and beef. Data from two farms in Wales, UK, were employed to undertake such an analysis for two system boundaries.

Within a system boundary that considers the embodied greenhouse gases (GHGs) in inputs and on-farm emissions, producing 1 kg of lamb releases 1·3–4·4 kg CO2 eq/kg live weight (case study farm 1) and 1·5–4·7 kg CO2 eq/kg live weight (case study farm 2). The production of beef releases 1·5–5·3 and 1·4–4·4 kg CO2 eq/kg live weight.

Within a wider system boundary that also includes GHG emissions from animals and farm soils, lamb released 8·1–31·7 and 20·3–143·5 kg CO2 eq/kg live weight on the two case study farms, and beef released 9·7–38·1 and 18·8–132·6 kg CO2 eq/kg live weight. The difference in emissions for this system boundary relates to nitrous oxides emitted from the organic soils on case study farm 2.

These values overlap with nearly all other studies of GHG emissions from lamb and beef production. No direct comparisons between studies are possible due to substantial differences in the methodological approaches adopted.

Global climate change is predicted to shift seasonal temperature and precipitation patterns. An increasing frequency of extreme weather events such as heat waves and prolonged droughts is predicted, but there are high levels of uncertainty about the nature of local changes. Crop adaptation will be important in reducing potential damage to agriculture. Crop diversity may enhance resilience to climate variability and changes that are difficult to predict. Therefore, there has to be sufficient diversity within the set of available cultivars in response to weather parameters critical for yield formation. To determine the scale of such ‘weather response diversity’ within barley (Hordeum vulgare L.), an important crop in northern conditions, the yield responses of a wide range of modern and historical varieties were analysed according to a well-defined set of critical agro-meteorological variables. The Finnish long-term dataset of MTT Official Variety Trials was used together with historical weather records of the Finnish Meteorological Institute. The foci of the analysis were firstly to describe the general response of barley to different weather conditions and secondly to reveal the diversity among varieties in the sensitivity to each weather variable. It was established that barley yields were frequently reduced by drought or excessive rain early in the season, by high temperatures at around heading, and by accelerated temperature sum accumulation rates during periods 2 weeks before heading and between heading and yellow ripeness. Low temperatures early in the season increased yields, but frost during the first 4 weeks after sowing had no effect. After canopy establishment, higher precipitation on average resulted in higher yields. In a cultivar-specific analysis, it was found that there were differences in responses to all but three of the studied climatic variables: waterlogging and drought early in the season and temperature sum accumulation rate before heading. The results suggest that low temperatures early in the season, delayed sowing, rain 3–7 weeks after sowing, a temperature change 3–4 weeks after sowing, a high temperature sum accumulation rate from heading to yellow ripeness and high temperatures (⩾25°C) at around heading could mostly be addressed by exploiting the traits found in the range of varieties included in the present study. However, new technology and novel genetic material are needed to enable crops to withstand periods of excessive rain or drought early in the season and to enhance performance under increased temperature sum accumulation rates prior to heading.

supplements of protected soya-bean–tallow were incorporated at 0, 1·7, 3·0 or 5·0 kg/day into a hay–concentrate diet and fed ad libitum to Friesian cows during the first 13 weeks of lactation.

Intakes of supplement during weeks 1–6 were 0,1·34, 2·25 and 3·18 kg/day and during weeks 7–13, 0, 1·64, 3·10 and 4·24 kg/day on each of the respective treatments.

As the lipid supplement increased there was a reduced intake of hay and concentrates, giving rise to reduced intakes of total, protein, and particularly ‘carbohydrate’ (non-protein, non-fatty-acid) energy. Apparent digestibilities, particularly of fibre, decreased as fatty-acid intake increased. After correcting for endogenous losses, true digestibilities of organic matter, carbohydrate, protein, non-fatty-acid lipid, total energy, calcium, magnesium and phosphorus were unaffected by the amount of supplement given, whereas fibre digestibility was reduced by increasing the supplement. Fatty acid digestibility was little affected up to an intake of 1·4 kg/day but above this there was a sharp reduction.

Yields of milk, milk energy, protein, fat and lactose were increased at low lipid supplementation but reduced at the highest supplementation when amounts of protein and carbohydrate digested were lowest.

Lipid supplementation reduced concentrations of rumen total volatile fatty acids in association with reduced, proportions of butyrate and. increased proportions of propionat. Plasma β-hydroxybutyrate and magnesium were reduced and plasma free fatty acids increased in cows given lipid supplemented diets.

There were no differences between treatments in plasma glucose, lactate or calcium nor in live-weight changes.

Fertilized ova have been transferred from Border Leicester to Welsh Mountain ewes, and vice versa. The oestrous cycles of the ewes were synchronized by progesterone treatment, and donor ewes were super-ovulated with PMS. 68–90 hr. after the onset of oestrus in the donors, thirty-seven ova, representing 58% of the ovulations, were recovered in vivo from thirteen ewes. Nineteen ova were transferred to eighteen recipient ewes and a total of eight pure-bred lambs were born to ewes of the opposite breed.

Transfers resulted in pregnancy when oestrus in the recipients commenced from 16 hr. before to 20 hr. after that in the donors; two of the ova which developed to term were 4-cell, five were 8-cell and one was a 16-cell ovum at the time of transfer. Four out of seven and four out of eleven transfers, using blood serum and Ringer's solution respectively, resulted in the birth of lambs. Prior to transfer to the recipients seven of the ova which developed to term were exposed for 30–45 min. at room temperature, whilst one developed after exposure for 70 min.

1. Most of the bees which drift do so during their orientation flights and before they become regular foragers.

2. Bees emerging in August and September drift less than those emerging earlier in the year.

3. Drifting varies considerably in different circumstances, and may be extensive.

4. Drones drift two to three times as frequently as workers.

5. An individual bee is more likely to drift from a small to a large colony than vice versa, but the greater number of bees flying from the large colonies may result in a net gain in bees by the smaller ones.

6. When hives are arranged in repetitive patterns, bees drift to hives occupying similar positions in the pattern to their own. When hives are arranged in rows, bees from the centre colonies drift more than those at the end, resulting in the latter colonies gaining numerically. In some circumstances, more bees drift to hives in one direction than in the opposite direction.

7. Facing hives in different directions and painting them different colours considerably reduces drifting, the facing of hives in different directions being of the greater significance.

1. The myoglobin contents of selected muscles in horse, pig, domestic fowl and pigeon, and in the foetuses of horse, pig, sheep and cattle, have been determined.

2. The order of increasing concentration of myoglobin in the adult animal (4 years) is given by the series heart, longissimus dorsi, diaphragm and psoas, the figures for draught horse being, respectively, 0·325, 0·465, 0·610 and 0·705% and for pig, 0·203, 0·280, 0·350 and 0·435%, and the ratios of these concentrations being the same in each animal.

3. In both draught horse and pig, it is shown that the concentration of the pigment rises rapidly from birth, and that, after 2 years in the horse, and 1 year in the pig, it remains fairly constant, except in the case of horse psoas and diaphragm where there is a slow, but significant, rise throughout life.

4. This relationship of myoglobin with age has been shown to be significant at a probability level of 0·1%.