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1.
An experiment was carried out during 1982 in which the effects of three differing harvesting systems on the field losses occurring during the conservation of grass as silage were examined. The treatments were either (a) harvesting herbage directly by means of a flail harvester (unwilted flail, UF), or (b) pre-cu ing of herbage with a rotary drum mower and lifting using a precision-chop forage harvester with wilting (WP) and without wilting (UP). Herbage was harvested on 26 May, 21 July and 7 September 1982. The mean yields of herbage produced from plots harvested by the three systems were not significantly different, with dry ma er (DM) yields of 12470, 12300 and 12230 kg ha-1 for the UF, UP and WP treatments respectively. However, field losses with the UP and WP treatments were greater than with the UF treatment (P<0·01). As a result the yields of herbage ensiled with the UP and WP treatments, 11690 and 11320 kg DM ha-1 respectively, were significantly lower than with the UF treatment, 12710 kg DM ha-1 (P <0·05). Wilting of first cut herbage for a period of 72 h resulted in a significant reduction (P<0·05) in digestible organic ma er (DOM) concentration (determined in vitro), whereas small increases in DOM concentration were observed following wilting of second and third harvest material.
It is concluded that, even under favourable weather conditions, both pre-cutting and wilting of herbage prior to harvesting can result in considerable losses of nutrients in the field.  相似文献   

2.
A mathematical model of the production, harvesting and utilization of maize and grass silage on a dairy farm with an autumn-calving herd is described. Using the model the comparative costs and benefits of growing and feeding maize in place of grass silage are examined for three sites in southern England. It is concluded that a winter milk production system based on maize rather than grass should improve profits by at least £30, and possibly by as much as £80 cow-1. This financial improvement is attributable to higher feed intakes and lower harvesting and fertilizer costs with maize silage. Simulating the results over a 10-year period also revealed that the switch from grass to maize should lower the risks in terms of the annual variability of silage yields and herd profits. Furthermore, it would appear unnecessary to completely turn over from grass to maize production to realize a significant financial benefit. Setting aside just 25% of the conservation area to maize and feeding a mixture of maize and grass silage is projected to increase profits from winter milk production by £30 to £45 cow-1.  相似文献   

3.
Over a 24-week period, three groups of dairy cows were continuously stocked at 8, 10 or 12 cows ha-1 between morning and afternoon milkings, and overnight were housed and offered grass silage ad libitum. Due to a prolonged drought, sward heights only averaged 4·1 cm.
The increase in daytime stocking rate led to a decline in herbage intake, and increases in silage intake. At the highest stocking rate (12 cows ha-1), the silage intake failed to compensate for the reduced herbage intake. Consequently the total dry matter and estimated metabolizable energy intakes were lower than for the 8 and 10 cows ha-1 treatments. Milk yields and milk composition were not significantly affected by treatment but the 12 cows ha-1 stocking rate gave the lowest milk and milk solids yields.
The utilized metabolizable energy (UME) on the grazed swards was greatest for the 10 cows ha-1 treatment. The sward cut to provide the silage had a UME level (GJ ha-1) 32% greater on average than the grazed swards during the same growth period. The total areas utilized for grazing and silage production for 8, 10 and 12 cows ha-1 were 0·240, 0·224 and 0·215 ha respectively. Fat and protein yields per unit area were greatest for the 10 cows ha-1 group.  相似文献   

4.
Two randomized-block experiments were conducted to examine the effects of frequency of harvesting grass for silage on the intake and performance of beef cattle. In both experiments swards of S24 perennial ryegrass were harvested at 63-, 49- and 38-d intervals throughout the growing season. Grass harvested before and after 10 July was ensiled separately and termed spring and autumn silage respectively. In Experiment 1 the silages were offered ad libitum either unsupplemented or supplemented with 2 kg barley per head daily to eighty-four Hereford-cross weaned, single-suckled steer calves of mean initial live weight 284 kg, in a 3 × 2 × 2 factorial design. Silage dry matter (DM) intakes and liveweight gains for the silages harvested at 63-, 49- and 38-d intervals were 4.80, 0.72; 4.49,0.76; and 4.62,0.78 kg d−1 for the spring silages and 4.69, 0.67; 4.59, 0.85; and 4.55,0.86 kg d−1 for the autumn silages respectively. There was no significant interaction between frequency of harvesting and concentrate supplementation. In Experiment 2 the silages were offered ad libitum and unsupplemented to forty-two Hereford-cross weaned, single-suckled steer calves of mean initial live weight 240 kg, and forty-two Hereford-cross store cattle of mean initial live weight 356 kg, in a 3 × 2 × 2 factorial design. Silage DM intakes and liveweight gains for the silages harvested at 63-, 49- and 38-d intervals were 4.94,0.49; 5.69,0.80; and 619,0.93 kg d−1 for the spring silages and 5.50, 0.61; 5.57, 0.72; and 505, 0.65 kg d−1 for the autumn silages respectively. There were no significant interactions between frequency of harvesting and type of animal. It is concluded that a cutting interval of 49 d commencing on 21 May is likely to be optimum for this type of sward except under exceptional weather conditions.  相似文献   

5.
Substantial annual fluctuations in the performance of arable silage mixtures, comprising Minerva forage pea and Goldmarker barley, were observed from ten annual sowings between 1977 and 1986, Total dry matter (DM) yield varied between 2·5 and 11·5 t ha−1. Dry matter content also ranged widely from 10·3% to 20·0% and there was a large variation in the proportion of peas in the DM (0·44 to 0·90). Almost 80% of this yield variation was due to the fluctuation in pea performance and over 60% of all yield variation was related to the variation in sunshine hours and air temperature.
In 1983 and 1984 differences in seed rate of between 20 and 140 kg ha−1 of Minerva and 80 and 160 kg ha−1 of Goldmarker influenced the forage composition at harvest, with the pea component capable of outgrowing and suppressing the other species when sown at over 80 kg ha−1. Very high yields of peas were associated with increasing stress on the undersown grass re-seed and were considered undesirable.
It was concluded that sowing rates of between 120 and 160 kg ha−1 for barley and a maximum of 60 kg ha−1 for peas would, in most years, provide the best compromise between attaining good arable silage yields and avoiding excessive dangers of damage of undersown grass re-seeds.  相似文献   

6.
A second cut of lucerne was wilted to 500 g DM kg−1 and either left untreated (control) or treated with formic acid (4.5 1 fresh forage t−1) or with a commercial inoculum of lactic acid bacteria (105 colony forming units (cfu) g forage−1). The forages were ensiled in 2-t capacity silos for 8 months, and later fed to six lambs (mean initial weight 27.7 ±1.60 kg) in a 3x3 duplicated Latin square with 27-d periods. Portions of the untreated and additive-treated forages were also ensiled in laboratory silos at 25 ° C for intervals up to 42 d. Results from the laboratory silos showed that the major increase in ammonia-N in silage occurred between 40 h and 7 d of fermentation; during this period, both formic acid and the inoculant produced a smaller increase in ammonia-N, than did the control. The pH of inoculated silage declined from 5.74 to 4.57 in 7 d, but it took 14 d for the pH of the control silage to fall below 5.0. Formic acid treatment immediately reduced the silage pH from 5.74 to 5.10 ( P < 0·01); the pH then remained unchanged until 21 d, after which it decreased slightly. When compared with control, lambs fed formic acid-treated silage consumed more ( P < 0·05) digestible organic matter; the response was associated with a trend towards decreased concentration of ammonia in plasma. Inoculation of lucerne silage did not ( P < 0·05) affect voluntary intake but increased ( P <0.05) apparent digestibility of fibre and tended to increase N retention.  相似文献   

7.
In two experiments, ewes in weeks 1–20 of lactation received either pasture only or pasture plus ad libitum conserved forage. Herbage height was maintained at 3·3–3·4 cm on both treatments by manipulation of stocking rate in the 24 plots (twelve per treatment) used for the experiment with additional ewes and lambs. In experiment 1, silage, which was of lower metabolizable energy (ME) and crude protein (CP) contents than the grazed herbage, was consumed at an average of 375 g dry matter (DM) ewe−1 d−1. In experiment 2 a strawmix, containing (g kg −1 freshweight) 480 g barley straw, 300 g concentrate and 220 g molasses, again with a lower ME and CP content than the grazed herbage, was consumed at an average of 165 g DM ewe −1 d −1. In both experiments ewes not receiving forage lost weight whereas those with forage gained weight and tended to have increased body condition scores. Offering silage or strawmix did not affect lamb liveweight gain or stocking rate.  相似文献   

8.
Nutrient losses during the in-silo period were determined following the ensiling of grass using three differing harvesting systems. The treatments were either (a) harvesting herbage directly by means of a flail harvester (unwilted flail, UF) or (b) pre-mowing of herbage with a rotary drum mower and lifting using a precision chop forage harvester with wilting (WP) and without wilting (UP). Herbage was harvested and ensiled over the period 26–29 May 1982, and a good fermentation was achieved with all three silages. Losses of dry matter (DM), organic matter (OM) and crude protein (CP) during the in-silo period were greatest with the UF system, intermediate with the UP system and lowest with the WP system. Gross energy losses followed the same trend with losses (as a percentage of ensiled levels) of 18·6, 9·8 and 4·4% for the UF, UP and WP systems, respectively. Gross energy loss as effluent accounted for 24% and 22% of total gross energy ensiled for the UF and UP treatments. Patterns of effluent flow differed between the two unwilted silages with a higher peak flow rate with the UF material. Total effluent production at 354 ml (kg DM ensiled)-1 was greater for the UF material than for the UP material (288 ml (kg DM ensiled)-1). Nutrient loss through surface waste was similar for all three silages whereas gross energy losses arising through residual respiration, fermentation and gaseous loss amounted to 149%, 6·7% and 31% of that ensiled for the UF, UP and WP silages, respectively. The results of this study, taken in conjunction with those of an earlier study where field losses were assessed, indicate that recovery of gross energy during silage making was very similar for the UP and WP systems and only marginally greater than that recovered with the UF system.  相似文献   

9.
Experiments were carried out over three seasons in which swedes were sown by precision drilling after ploughing and conventional cultivation or by direct drilling with two types of drill at two row widths with and without shallow cultivation. The swedes were sown in June or early July following a first silage cut and sward desiccation with paraquat. Precision drilling with inter-row cultivation and singling gave a uniform weed-free stand and had the highest mean yield of over 8 t DM ha−1 Where hoeing was omitted yields were reduced due to weed competition. Yields following direct drilling were lower than with precision drilling due to uneven plant establishment, weed competition and grass regrowth. A shallow rotavation prior to direct drilling improved uniformity and yields and reduced grass regrowth. Direct drilling produced high numbers of small roots. The highest root yields were associated with sowing in early June and harvesting in December or January. Overall yields from the silage cut plus direct drilled swedes and silage cut plus precision drilled swedes were 12 and 13 t DM ha−1respectively compared with about 14 t DM ha−1expected from a grass sward.  相似文献   

10.
Ensiling of manured crops—effects on fermentation   总被引:1,自引:0,他引:1  
The quality of silage from crops fertilized with cattle manure and an inorganic fertilizer was compared in experiments from 1985 to 1989. Manure was spread either as farmyard manure (FYM, 25t ha−1) or as slurry (20-50t ha−1). Crops were direct cut (approximately 200 g DM kg−1) or wilted (approximately 300 g DM kg−1), precision chopped and ensiled in experimental silos. Silage was treated with 4 kg 85% fonnic acid t−1 fresh matter (FM), an inoculant or no additives. The use of manure, particularly FYM, resulted in more Bacillus spores on crops at harvest compared with fertilized crops. Clostridium spores increased as a result of manuring in 1989 only on FYM-treated crops. Differences in the chemical composition of crops were usually small between fertilizer treatments. The quality of silage from slurry-dressed crops, compared with that of silage from fertilized crops, varied between years. The FYM resulted in reduced silage quality, i.e. high pH values (> 4·5), high ammonia N (> 150 g kg−1 total N) and butyric acid (> 6·3 g kg−1 water) concentrations, and high numbers of Bacillus (105 g−1 FM) and Clostridium spores (105 g−1 FM). The concentration of lactic acid was low (≤ 12 g kg−1 water). Wilting and additives generally improved silage quality and reduced the differences between treatments. However, the efficiency of the inoculant on farmyard manured crops was limited.  相似文献   

11.
A total of 1009 samples of silage made in bunker silos on commercial farms between 1972 and 1978 was analysed to investigate the effect of herbage water-soluble carbohydrate content (WSC) and weather conditions at ensilage on fermentation as measured by ammonia-N concentration and pH of first-cut grass silages.
Silage dry matter (DM) content had the major effect on fermentation. Factors influencing silage DM were rainfall and hours of sunshine during silage making, and DM content of the grass cut. WSC content of herbage ensiled also had a significant effect on subsequent fermentation. The major influences on herbage WSC were hours of sunshine and rainfall during the growing season.
The effect of chemical additives, albeit at poorly defined and often inadequate rates, was small in comparison to that of silage DM.
The minimum DM necessary to produce well-fermented silage without additive was approximately 260 g kg−1. Use of formic acid significantly reduced this requirement to 240 g kg−1 and to 252 g kg−1 for sulphuric add + formalin. The results indicate that the minimum herbage WSC necessary to prevent a clostridial fermentation developing in silage with a DM content of 230 g kg−1 is approximately 37 g kg−1 without additive and 30 g kg−1 with formic acid.
It is concluded that on commercial farms, weather conditions i.e. amount of rainfall and sunshine prior to and at ensilage, have a greater effect on subsequent silage fermentation than additive use.  相似文献   

12.
The effect of adding rolled barley on the ensiling characteristics and nutritive value of lucerne and corn ( Zea mays ) forage was studied using 19-1 plastic mini-silos. Other factors evaluated with lucerne were the effect of wilting and added lactic acid bacteria. Rolled barley was added at rates of 0, 50, 100 and 150gkg−1 (wet weight) to lucerne or corn forage. Lucerne was ensiled at 170–330 g kg−1 dry matter (DM) and lactic acid bacteria were applied at 105g−1 wet forage. Addition of rolled barley consistently improved the fermentation of lucerne by lowering the pH and decreasing the concentration of acetate and ammonia nitrogen. Wilting of lucerne had variable effects on fermentation in two experiments. The addition of lactic acid bacteria improved fermentation by decreasing the concentrations of acetate and ammonia nitrogen, improved the nutritive value by increasing the in vitro dry matter digestibility (IVDMD), and was associated with decreased amounts of lactic acid. Corn was ensiled at 250 g kg−1 DM, and added rolled barley had little effect on the fermentation of corn silage. The digestibility of all silages determined in vitro was improved by the addition of rolled barley.  相似文献   

13.
Estimates of the total acidity of silage effluent from a range of first-cut silages varied from 1025 to 21,125 mg Ca CO3 per l with a weighted mean of 8817 mg l-1. Quick-lime (CaO), hydrated lime [Ca(OH)2] or caustic soda (NaOH) were found to be effective neutralizing agents when thoroughly mixed with the effluent. Results from seven field-plot experiments carried out between 1973 and 1977 involving application of silage effluent to grass swards are reported. Leaf scorch occurred when silage effluent with a total acidity equivalent to more than 6000 mg CaCO3 per l was applied at rates exceeding 50 m3 ha-1 to swards with several weeks regrowth. Scorch was most severe when applications were made during periods of dry sunny weather and to mechanically damaged swards. In these conditions reducing the total acidity to below 2000 mg CaCO3 per l by neutralization or dilution allowed rates of over 100 m3 ha-1 to be applied without harmful effects.
Acid neutralization was found to be unnecessary when silage effluent was applied to recently cut swards. Here rates of up to 150 m3 ha-1 were applied without adverse effects and generally resulted in increased grass growth.  相似文献   

14.
The results are reported of a 2-year plot experiment investigating the potential of lucerne as a silage crop in a comparatively high-rainfall area (annual average of about 900 mm). The performance of the lucerne on the remainder of the field in which the plot experiment was located is also discussed. With below-average rainfall in the sowing year a good establishment was obtained and a single cut to a stubble height of 75 mm in August gave a dry matter yield of 3 t ha-1. In the first harvest year, summer rainfall was again below average and a total dry matter yield of 13·8 t ha-1 resulted from three cuts to 75 mm above ground level. However, the total yield was reduced to 10·11 ha-1 in the second year when the rainfall was considerably above average. Attempts to increase the feeding value of the lucerne herbage by increasing cutting frequency and by increasing cutting height showed little effect over the standard system of three cuts to a stubble height of 75 mm. The effects of applying potassium fertilizer at rates supplying 100,200 or 300 kg K ha-1 either as a single spring dressing or in equally divided dressings were not significant in either of the two years  相似文献   

15.
A series of preliminary trials is described to assess the potential and some of the cultural requirements of new cultivars of forage peas grown as pure stands in the west of Scotland. Optimum sowing date was late March for harvesting 15 weeks later to leave sufficient of the growing season for a catch crop or the establishment of a grass sward. Yield of dry matter (DM) at harvest was approximately 6 t ha-1 but DM concentration varied greatly with season. The digestibility of the organic matter was of the order of 0·700 and the crude protein concentration in the DM 170 g kg-1. DM yield increased with increasing seed rate up to 200 kg ha-1 the maximum rate tested.  相似文献   

16.
In view of the revived interest in sainfoin, an economic assessment of the prospects for an expansion of its area in Britain has been attempted. It is estimated that potentially it could be grown on 950 × 103 ha of the agricultural area of England and Wales, though it is unlikely in the near future that it would exceed 20 × 103 ha, even if economic conditions were favourable. Comparison of the energy and protein yields of sainfoin, red clover and lucerne under conservation management indicates that one of the attractions of sainfoin is its high protein content. However, an assessment of the costs of production and utilization of sainfoin indicate that, for it to be a more widely used legume, sustainable dry matter (DM) yields would need to be increased by 35% to about 11.5 × 103 kg DM ha−1. At the same time, although growing sainfoin as a mixture with grass appears to improve the economic attractiveness of the crop, silage production costs (kg DM)−1 are still about 15% lower on pure grass swards. However, trials in the UK, Canada and Rumania have shown that, compared to current UK levels, sainfoin yields can be significantly increased.  相似文献   

17.
A mixture of perennial and hybrid ryegrasses(234 g DM kg-1) was forage harvested and ensiled after a 24-h wilt in good ensiling conditions in 2-t capacity silos with no additive application (control) or with the application of either Lactobacillus plantarum , 4 × 106 (g fresh weight of grass)-1, or of 31 formic acid t-1. Sufficient 2-kg capacity laboratory silos were also filled with grass to monitor the changes in chemical composition of the ensiled grass with time. In laboratory silos, inoculation with L. plantarum resulted in a more rapid fall in silage pH ( p < 0.001) and a more rapid production of lactic acid ( P < 0.001) than in the control silage. At the end of the storage period (laboratory silos, 80 d; 2-t silos, 200-300 d), the inoculated silos had lower pH ( p ammonia-N (g kg N1) and acetic acid contents ( p < 0.01) and higher water soluble carbohydrate (WSC), lactic acid (P<00.1) and ethanol ( p < 0.05) contents than the control silage. The formic acid-treated silage had significantly lower contents of ammonia-N (g kg N-1, p < 0.05), acetic and tactic acids (p<0.01) and higher contents of WSC and ethanol ( p < 0.01) than the control silage. When fed to wether sheep, the digestibilities of DM, organic matter and gross energy were not altered by additive treatment. The digestibility of modified acid-detergent fibre was lower for both the inoculated ( P < 0.01) and formic acid-treated silages ( p < 0.05). However, N retention was improved ( p < 0.05) by both additive treatments. Silage intake was improved ( p < 0.01) by additive treatment from 53.4 (control) to 58.0 (inoculated) and 60.4 (formic acid) g DM (kg live weight0.75)-1d-1.  相似文献   

18.
Dairy farming systems are important sources for the emission of a number of materials that include various forms of nitrogen (NO3, N2O and NH3) with potential environmental impact. The present paper is a systems synthesis study and assesses the likely impact of changes in management on N flows and losses. These include tactical fertilizer adjustment, slurry injection, maize silage production and the use of white clover as an alternative to fertilizer N. Implications for greenhouse gases (N2O and CH4) and support energy have also been considered. Substantial reductions in inputs and total and proportional losses by all die options considered were predicted by this study. Thus, using a tactical approach to fertilizer application and injecting slurry or using 50% maize silage reduced overall N losses from 160 (under conventional management) to 86 and 109kg Nha−1 respectively. Combining both possibilities reduced losses further to 69 kg ha−1. Although use of white clover, especially at low contents in the sward, was the most effective regime to reduce losses, this was at some cost to production so that losses per livestock unit (LU) did not always differ from those under other managements. Changing the N management had consequences for greenhouse gas emission with an estimated maximum 70% reduction in N2O release. The effects on CH4 emissions were relatively small. Substantial reductions in support energy costs were also obtained: these arose mainly from the reduction in fertilizer N use, which represented 66% of the total support energy in the original system.  相似文献   

19.
In field experiments conducted over 2 years, triticale was compared with barley, bread wheat and oats for its dual-purpose (forage and grain) capability.
The effect of spring forage removal on grain yield ranged from small yield increases (in the triticale and barley genotypes that otherwise lodged) to a 53% decrease, and was dependent on species, genotype, stage of development when cut, and time for recovery before grain harvest. A key factor influencing grain yield after early cutting was the number of spikes that developed.
The complete types of triticale were better than the one substituted type tested for dual purpose but, as there is variability among them, selection for good mixed aptitude is possible.
The production of the best triticale averaged over 2 years 3 t of forage DM ha-1 (with 684 kg of crude protein ha-1) and then 4–3 t of grain ha-1. In this instance, neither the grain yield nor the number of spikes per plant were reduced after clipping, in spite of the fact that the shoot apices were removed.
Plant height and lodging were reduced by a forage cut. In triticale, the number of days to heading was increased even more when the cut was late, but no effect was observed in barley.  相似文献   

20.
Multiple cropping has been used for many years to increase production in temperate areas of Europe where the growing season is favourable and is important when land area is limiting.
The purpose of this 3-year study was to determine how several different cropping systems affected forage production potential at three rainfed locations in northwestern Spain (Galicia). The cropping systems compared were: single crop maize; double crop systems of maize-rye, maize oats+ vetch, and maize-Italian ryegrass; three crops in a two-year rotation of maize-Italian ryegrass (12-months) forage rape; 2-year pasture maize and two contrasting 3-year grass-legume mixtures.
There was an increase in dry matter (DM) production as cropping intensity increased. The one-year double cropping systems always yielded more than three crops in two years, which in turn outyielded single crop maize or 3-year pastures. The highest DM yields were 20–9 t ha-1 from the maize-oats-I-vetch rotation. Maize was the principal crop determining total production, yielding about 70% of the total DM for the double cropping systems. The maize component gave similar annual yields in the multiple crop and maize-pasture rotations, but the use of maize allowed double cropping, which increased production compared with 3-year pasture.
Forage rape gave the highest in vitro dry matter digestibility (IVDMD) of 773–815 g kg-1 while the oats-I-vetch mixture gave the highest crude protein (CP) concentration (105-217 g kg-1). The maize crops had the lowest CP content (62-76 g kg-1) though digestibility was high (653-713 g kg-1).  相似文献   

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