THE EFFECT OF CONDITIONING ON THE RATE OF DRYING AND LOSS OF NUTRIENTS IN HAY

Treating cut herbage with a roller-crusher or a crimper resulted in an increased drying rate compared with tedding. A higher rate of drying was obtained when herbage was treated within a short period of the crop being cut, this effect being more marked with the crimper than with the tedder. Nutrient loss was higher when a crimper was used than with a roller-crusher or tedder. Applying water at an early stage in the drying process did not have a marked effect on nutrient loss, but appeared to decrease the digestibility of the crimped hay.     

A COMPARISON OF NUTRIENT LOSSES IN BALED HAY MADE FROM FORAGE-HARVESTED, CRIMPED OR TEDDED SWARDS WITH THOSE IN BARN-DRYING

Two experiments were conducted to study the effect on nutrient loss and feeding value of making hay by different means, using a barn-drier, a forage-harvester, a crimper and conventional tedding. Both forage-harvesting and crimping of the herbage significantly increased the rate of drying, compared with tedding alone. In Exp. 2 this effect enabled the crimped and forage-harvested hays to be baled for storage 3 days earlier than the tedded hay. The use of the forage-harvester significantly reduced the yield of herbage compared with conventional mowing. Nutrient losses from cutting until storage were highest for the forage-harvested hays, the loss of dry matter between cutting and storage in the forage-harvested hays being 39·9 and 19·3%, respectively, in Expt 1 and 2 with corresponding losses in the conventionally made hays of 7·1% and 9·3%. Crimping the hay resulted in higher nutrient losses than tedding. In Expt 2 there was a loss of dry matter of 17·5% in the conventionally made hay during an 18-week storage period, compared with 3·6% in barn-dried hay, 10·8% in forage-harvested hay and 8·8% in crimped hay.
In Expt 2, in which digestibility determinations were made, conservation decreased the total digestible nutrients and starch equivalent in all treatments. The use of the barn-drier gave the most efficient conservation of total digestible nutrients, followed by the crimped, forage-harvested and conventional treatments in that order. The starch equivalent values of hays made from the same sward were 43·0 when barn-dried, 39·8 when crimped, 38·6 after forage-harvesting and 31·6 after tedding.     

THE EFFECTS OF TYPE OF CUTTER AND HEIGHT OF CUTTING ON THE RECOVERY OF FOUR GRASS VARIETIES

S23 and S24 Lolium perenne and S37 and S143 Dactylis glomerata were cut to heights of 1 1/2 and 4 1/2 in. in a replicated experiment, using: a flail harvester, a reciprocating mower, and a reciprocating mower followed by a flail harvester to collect the wilted grass.
At the short cutting height there was a marked depression of regrowth of all grasses following the use of the flail harvester (P<0.01), compared with the other mowing treatments. No such effect was observed at the higher level of cutting. Close cutting with a flail forage harvester was shown to be detrimental to regrowth, but the reasons for this effect are not clear.     

CHANGES IN CHEMICAL COMPOSITION AND THE LOSS OF NUTRIENTS IN TRIPODED AND SWATH-CURED HAY

The changes in chemical composition during haymaking, the loss of nutrients in the field and during storage, and the nutritive value of swath-cured and tripoded hay were compared. In good weather no advantage was gained by tripoding the hay. The nutritive value of the hays made by the two methods was similar and the loss of dry matter in the field slightly lower in the swath-cured hay. In a bad season, however, the nutrient loss in the swath-cured hay greatly exceeded that occurring in the tripoded hay and the starch equivalent, as shown by the results of digestibility trials, was markedly lower for the swath-cured.     

THE SIMULATION OF ANIMAL RETURNS IN GRASSLAND EXPERIMENTATION

An experiment was carried out on a grass/white-clover sward at North Wyke to evaluate the use of mixtures of inorganic and organic nutrient sources to simulate the nutrient effect of animal excreta, both with and without overall PK fertilizer. Grazing with sheep and the return of excreta from caged sheep both increased herbage yields, as did artificial return treatments. Artificial return treatments giving 75% of the nutrient level returned by excreta gave yields comparable with grazing. The effect of the simulated return treatments was not influenced by PK application. Grazing gave a very different botanical composition to that from the treatments in wbich natural or simulated excreta were returned to cut swards. Mixtures simulating excreta may replace the nutrient effect of the grazing animal, but not its physical effect, in some forms of grassland experimentation. They are not recommended for fertilizer trials.     

EFFECTS OF FOLIAR APPLICATION OF COPPER SULPHATE ON THE COPPER CONTENT AND YIELD OF HAY

Foliar application of CUSO₄ to mature grass to increase the Cu content of the hay crop was markedly affected by rainfall within 24 h of the time of application. The mean Cu concentration of hay treated with 5·6 and 11·2 kg CuSO₄/ha was 100 and 208 ppm, respectively, when no rainfall occurred during this period, but only 24 and 41 ppm when rain fell within 24 h. Rain 4 or 5 days after spray application had no effect on the ultimate Cu concentration of the hay. It is suggested that sheep could safely graze the aftermath as, with one exception, concentrations of Cu found were only from 11·4 to 20·6 ppm. l±l kg CuSO₄/ha applied in dry conditions was sufficient to raise Cu concentrations in hay to levels which should preclude the occurrence of Cu deficiency when fed to cattle in winter. Reductions in hay yield following CUSO₄ applications in dry weather suggest a need to examine the use of more dilute sprays, or other means for increasing the Cu content of hay.     

THE SIGNIFICANCE OF VIRUS DISEASES FOR THE PRODUCTIVITY OF GRASSLAND

The effect of cocksfoot streak virus (CSV) on Dactylis glomerata L. and barley yellowdwarf virus (BYDV) on Lolium perenne L. was investigated under both single-plant and simulated-sward conditions. The effect of cocksfoot mottle (CFMV) was examined on single plants. CFMV was lethal, and in conditions of inter-plant competition CSV was semi-lethal and BYDV was non-lethal. When the virus was lethal, a considerable lag-phase was observed between mortality and complete compensation in yield. When the virus was non-lethal, plant growth was restricted, either horizontally (CSV) or vertically (BYDV). In mixed, healthy and infected plant populations healthy individuals compensated only for reductions in lateral growth.
CSV infection transformed plants of a pasture variety into 'hay' types and BYDV infection transformed plants of a hay variety into 'pasture' types. CSV increased the plant's aggressiveness in hay conditions, but reduced its ability to withstand frequent defoliation. Conversely, BYDV increased the plant's aggressiveness in pasture conditions, but reduced it in hay conditions. Compensation from healthy plants occurred only in CSV-infected swards subjected to frequent defoliation. Some possible reasons for the absence of compensation in other treatments are discussed.     

THE USE OF BARN-DRIED HAY AND SILAGE IN FATTENING YOUNG BEEF CATTLE

A series of trials was carried out in which barn-dried hay and silage were fed to young fattening cattle with or without supplementary barley. Liveweight-gains on silage and barn-dried hay alone were too low to provide an adequate finish during winter feeding. Liveweight-gains on hay alone were always higher than those obtained on silage alone, the difference being more marked in lighter animals. There was a marked response to supplements of 3 and 4 lb (1.4 and 1.8 kg) of barley, the response being significantly greater in silage-fed cattle than in those fed on barn-dried hay. There was some evidence of growth compensation with the introduction of a barley supplement to cattle on silage diets, but there was no such response in those fed on hay. Compensatory growth was not accompanied by improved digestibility or N retention.     

SOME EFFECTS OF MECHANICAL TREATMENTS AND SURFACE SOWING ON ROUGH HILL GRAZINGS

An experiment involving two adjacent, but contrasting, sites was conducted to examine the effect of using the rotary cultivator and the forage harvester as instruments in the improvement of indigenous hill swards at 1600 ft alt. by surfaee sowing. On a dry sward dominated by Nardus/ Festuca, both an autumn and a spring rotary cultivation were necessary to give the highest number of established seedlings. This also resulted in the greatest improvement in hotanieal composition. On a wetter Molinia-dominant sward, two separate rotary cultivations did not increase seedling establishment, compared with a single rotary cultivation. On the dry site, an autumn and a spring topping with a forage harvester established fewer seedlings, but on the wetter site the difference as compared with rotary-cultivation treatments was not significant. On this wetter site, topping by forage harvester gave an improved botanical composition by effecting a reduction in Festuca species to give a sward dominated by Agrostis and timothy.     

FACTORS AFFECTING THE VOLUNTARY INTAKE OF SILAGE AND HAY

Experiments with cows and sheep are described in which the voluntary intakes of hay and silage of differing digestibility were determined. The voluntary intake of hay increased consistently with increasing digestibility, but the relationship was not as well defined for silage. The addition of concentrates depressed the intake of hay, and this effect was more marked for hay with a high digestibility than with poorer quality hay. Concentrates appeared to depress the intake of hay by sheep more than by cows, an effect which was again more marked when the hay had a high digestibility value.     

A REVIEW OF NUTRIENT LOSSES AND EFFICIENCY OF CONSERVING HERBAGE AS SILAGE, BARN-DRIED HAY AND FIELD-CURED HAY

A review of American literature indicates that barn drying of hay and silage making are both greatly superior to the field curing of hay in preserving nutrients. This is true of total dry matter, crude protein, ether extract and ash; crude-fibre losses are greater in silage making. Energy losses run parallel with dry matter. Bam drying of hay with heat preserves a rather greater proportion of nutrients than does silage making.
Chemical composition and digestibility are mostly a function of stage of maturity of the crop at the time of cutting. Actual carbohydrate (energy) losses are greater than protein losses in all methods. The influence of method of conservation is unimportant if conservation is properly carried out, but considerable deterioration can result from bad application. Field-cured hay usually suffers most in this respect, due to weather damage.
The conservation processes reviewed have no influence per se on feeding value where each is applied under ideal conditions. Differences found in practice are usually linked to the stage of maturity or to weather damage, which explains the usually superior feeding value of silage and barn-dried hay over field-cured hay.
When the efficiency of each method is compared by determining the quantity of milk produced from equal areas of forage, conserved in the three different ways, barn-dried hay is somewhat superior to silage, but both are greatly superior to field-cured hay.     

The effect of propionic acid on the storage losses of hay

Storage losses in moist hay treated with propionic acid were compared with those occurring in untreated moist hay in two experiments and with field-cured hay in three experiments. Dry matter losses in treated hays ranged from 41 to 8.6% and from 1.7 to 12.6% in untreated hays. Digestible organic matter losses in both treated and untreated hays were generally greater than dry matter losses. Only in one experiment did propionic acid application significantly reduce nutrient losses in moist hays. Nutrient losses, and water-soluble carbohydrate losses in particular, were shown to be correlated with maximum and cumulative bale temperatures during storage in two of the experiments. The rise in hale temperatures during storage was reduced in all three experiments, to a greater or lesser extent, by application of the additive. Loss of propionic acid from the hay during and after application was very large. In the three experiments 86.2, 85.3 and 85.6% of the acid applied was lost by the end of the storage period. Acid distribution studies indicated that variation in acid concentration within bales was as great as between bales. It was concluded that more research is needed into applicator design and position on the baler and into alternative application methods if the benefits of propionic acid as a moist hay preservative are to be fully exploited.     

THE CONSERVATION OF HEAVILY–WILTED BALED HERBAGE IN SEALED POLYTHENE CONTAINERS

A conservation experiment is described in which the losses in ensiling heavily–wilted, baled herbage of 49–58% dry–matter content in a completely sealed polythene film is described. In addition, a comparison is made between silages with and without sodium metabisulphite added as a preservative. The mean DM loss for the control silages was 11.1%, and that for the metabisulphite–treated silages 12.8 %. These losses, and the individual crude–nutrient and digestible–nutrient losses are compared with those obtained for heavily–wilted and conventional silage made in lined trench silos. Metabolizable energy values for the grass and silages are also presented.     

THE DISTRIBUTION OF CARBOHYDRATES, NITROGEN AND LIGNIN IN SOLUBLE FRACTIONS OF THE STEMS AND LEAVES OF LUCERNE HAY

The nitrogen-free extractive (or soluble carbohydrate) and total nitrogen contents of the stems and leaves of lucerne hay were separated into three fractions, soluble in (a) 90% ethanol, (b) cold water, and (c) acid + alkali of the same concentrations as used in the crude fibre determinations. Total and "soluble" lignin contents were also determined.
The soluble carbohydrates in the stems comprised a lower proportion of the simpler types (90% ethanol soluble) and a higher proportion of a more complex nature (acid + alkali soluble) than in the leaves. The differences between the 90% ethanol soluble fractions were not due to the sugars but to unidentified materials which would include oligosaccharides, acids, saponins and possibly other constituents of an unknown nature.
The lignin content of the stems was more than three times that of the leaves, but, in both parts of the plant, the amount of "soluble" lignin was small.
In the stems, "protein" nitrogen constituted a lower proportion of the total nitrogen, and was possibly of a less digestible type than that in the leaves.
These results added emphasis to the importance of preventing leaf loss during the conservation of lucerne hay, not only to prevent actual loss of material but also in order to preserve its nutritive value.     

THE STATE OF HAYMAKING TECHNOLOGY—A REVIEW

The main objectives of research and development In haymaking are to minimize dependence on weather and to reduce loss of nutrients. Treatment of a cut crop, especially by mechanical conditioning, shortens drying time substantially while the use of chemical desiccants before or after cutting may also increase the drying rate. The advantages of terminating field exposure before drying has been completed are particularly important. Barn drying from about 40% moisture content (m.c.) wet basis has given good results. A useful alternative might be the application of preservatives to hay of high moisture content. The suppression of harmful spores, whether through barn drying or preservative treatment, lessens the risks to human and animal health.     

THE EFFECT OF A COVER CROP ON THE SEED PRODUCTION OF LEAFY COCKSFOOT S26

There was a significant reduction in the seed yield of S26 cocksfoot in the first harvest year following undersowing in oats. Yields were markedly improved, however, by the application of extra nitro-chalk in spring, by using a partial cover crop and by cutting the oats for silage.
Over three harvest years the financial returns were very similar for all treatments studied.     

THE INTAKE OF HAY AND SILAGE BY COWS

Three comparisons were made, with non-lactating fistulated cows, of the voluntary intake of silage and hay prepared from similar herbage. On average 28% more dry matter was eaten as hay than as silage. Silage and hay had similar digestibilities, but silage residues tended to remain in the gut longer than those of hay. The amount of digesta in the reticulo-rumen immediately after a meal ad lib . was greater with hay than with silage. The cows spent longer eating and ruminating per kg dry matter of silage than of hay. The results are discussed in relation to possible factors determining the voluntary intake of silage.     

A COMPARISON OF THE PRODUCTIVITY OF ABERYSTWYTH-BRED AND COMMERCIAL GRASS VARIETIES IN SMALL FARM UNITS

A comparison of Aberystwyth-bred and commercial grass varieties on two small farms of approximately 17 acres was started in April 1958. The 10 plots comprising each unit are scattered in pairs over a total area of 35·5 acres [used from 1951 for a grazing management experiment (1, 2)]. The management and results for the first three years are given in this paper.
Varieties for both long- and short-term leys were compared; the re-seeding plan and seeds mixtures used are detailed. The stock numbers, grazing management and fertilizer treatments were kept as nearly similar as possible for the farms and for the individual mixtures. Figures for utilized herbage production from individual plots, assessed from grazing data and from sample cuts taken during silage and hay making, are discussed in relation to botanical composition. The levels of production are given in terms of utilized starch equivalent, live-weight gain, wool from the ewes and cattle grazing days. All show consistent differences in favour of the Aberystwyth-bred varieties, but mask a difference in favour of Danish compared with S37 cocksfoot.     

THE PRODUCTION OF DRY MATTER BY SWARDS OF PERENNIAL RYEGRASS, DIFFERING IN AVERAGE AGE OF FOLIAGE

Leaves of different ages were removed 7 times between June and October. Each defoliation was timed to match the appearance of successive leaves on each tiller. The removal of leaves at progressively younger stages reduced total production above ground, but the most severe treatment, the removal of all expanded leaves repeatedly, still produced about 75% as much as the least severely defoliated sward. Clipping with shears 3 times reduced yield as much as removing all expanded leaves 7 times. A crop allowed to grow untouched apparently produced more than any defoliated treatment, but this may have been an artefact.
The lower production following increasingly drastic defoliation was not associated with reduced concentrations of nitrogen or potassium in the foliage removed, or in the crop left behind. The total quantity of these elements recovered in the crop was greatest in those treatments where least dry matter was produced. Explanations for the results depend on the capacity of swards of predominantly young leaves to assimilate carbon more rapidly than those containing old and senescent tissue.     

THE USE OF THE FORAGE HARVESTER IN THE IMPROVEMENT OF ROUGH GRAZING

Considerable improvement has been achieved in rough grazings by fairly frequent close mowing with the forage harvester or flail mower, particularly when combined with manuring and surface seeding.
The implement has proved capable of tackling very tough vegetation and converting it into grazing swards of fair value and good botanical composition. Undesirable species have been largely eliminated by treatment over two growing seasons.
The method is believed to compare favourably in cost with sward renovation by cultivation or by herbicides.