COMPARATIVE STUDIES OF PERENNIAL RYEGRASS, TIMOTHY AND MEADOW FESCUE

The growth of calves grazing pure swards of perennial ryegrass, timothy and meadow fescue at low grazing pressure was measured. Organic-matter intake was estimated on three occasions during the grazing season. In 1963 rest periods of 7 days in April and May and of 21 days in June-Octoher were used hetween 7-day grazing periods. In 1964 the effect of long (35–55 days) and short (15–25 days) rest periods hetween 3.5-day grazing periods were compared. There were no measurable differences in intake hetween the calves on the three grass species in 1963. In 1964 faecal production was higher with timothy than with the other species and with small differences in digestihility, the intake on this species was higher. The faecal production and intake were higher, hut not significantly so, with the long-rest management in the second year. The liveweight gains of the calves grazing the three species were similar in 1963; in 1964 gains with meadow fescue were lower than with the other species from 13 April to 22 June but this was the only significant difference. The results obtained on slaughtering the calves at the end of each summer are presented.     

COMPARATIVE STUDIES OF PERENNIAL RYEGRASS, TIMOTHY AND MEADOW FESCUE

The voluntary intake by calves of perennial ryegrass, timothy and meadow fescue, when cut with a flail-type forage harvester and fed fresh, was measured. In 1963 a single management was used and rest periods between cuttings were of 10 or 11 days in April and May and 21 days in June to October. In 1964 the effects of managements with long (35–55 days) and short (15–25 days) rest periods were compared. The increases in rest periods within managements were made in June or July. The voluntary intake of the 3 grass species was not significantly different and the live-weight gains made on the species were similar in both years. Digestibility of all species was higher with the short rest periods than with the long ones and this resulted in higher intakes and liveweight gains from the short-rest-period management.     

COMPARATIVE STUDIES OF PERENNIAL RYEGRASS. TIMOTHY AND MEADOW FESCUE.

Hays made, mainly in May, from pure swards of perennial ryegrass, timothy and meadow fescue were fed to 8-month old steers in 1963 and to yearling steers in 1964. High-quality hay was obtained, but no significant differences in growth rate were observed between calves fed on hays from the 3 species. In 1963, barley (1.5 kg DM/ head per day) was fed, in addition to the hays, to half the animals and resulted in a significant increase in live weight gain. The productivity, in terms of liveweight gain/ unit area, of each species when managed for hay and‘zero grazing', or hay and grazing, was calculated. On this calculation perennial ryegrass was the most productive species.     

THE DIGESTIBILITY OF THE LEAVES AND STEMS OF PERENNIAL RYEGRASS, COCKSFOOT, TIMOTHY, TALL FESCUE, LUCERNE AND SAINFOIN, AS MEASURED BY AN IN VITRO PROCEDURE

Determinations of the in vitro digestibilities of leaf-blade, leaf-sheath and stem fractions of the grasses cocksfoot, perennial ryegrass, timothy and tall fescue and of the leaves and stems of lucerne and sainfoin have shown that all parts of the plant have a high digestibility at early stages of growth. With increasing maturity, however, the digestibility of the stem falls off at a much faster rate than that of the leaf; in grasses, leaf-sheath digestibility declines at an intermediate rate. The decline of digestibility is associated with a reduction in the content of water-soluble and protein constituents in the plant, and with a reduction in the digestibility of fibre. This may provide a biochemical basis for the selection of forage plants of high digestibility in plant-breeding studies.     

THE INFLUENCE OF SEASONAL CHANGES IN LIGHT ENERGY ON LEAF AND TILLER DEVELOPMENT IN RYEGRASS, TIMOTHY AND MEADOW FESCUE

The importance of leaf area as a determinant of yield in herbage crops is now widely realized. Selection for a rapid increase in leaf area might therefore be a useful approach to the problem of breeding for yield.
The present paper describes the seasonal changes in two important components of leaf area, rate of leaf and tiller production, in contrasting varieties of ryegrass, timothy and meadow fescue. The regular seasonal variation in these components in the glasshouse is shown to be determined primarily by available light energy, the species and varieties differing in their response to changes in light energy. The possibilities of selection for these components of leaf area are discussed, but it is pointed out that individual leaf size must also be considered.     

EFFECTS OF WHITE CLOVER ON THE BOTANICAL COMPOSITION OF SWARDS OF RYEGRASS, TIMOTHY AND MEADOW FESCUE AND MIXTURES OF THESE THREE

Results are presented to show the effect of white clover (Trifolium repens) and of applied N on the hotanical composition of swards sown with perennial ryegrass (Lolium perernne), timothy (Phleum pratense), meadow fescue (Festuca pratensis) and mixtures of two and three of these species. White clover had a more favourahle effect on the growth of perennial ryegrass than on either timothy or meadow fescue both in terms of yield and in terms of tiller numbers. Tiller numbers of rough-stalked meadow grass (Poa trivialis) were increased and tiller numbers of Agrostis species were reduced by application of N and by inclusion of clover. Possible reasons for these effects are considered.     

THE EFFECT OF LEVEL OF NITROGEN AND CUTTING TREATMENT ON LEAF AREA IN SWARDS OF S48 TIMOTHY (PHLEUM PRATENSE, L.) AND S215 MEADOW FESCUE (FESTUCA PRATENSIS, L.)

Leaf-area index was increased by nitrogen application, but the increase was restricted by frequent cutting, which limited the incidence of high leaf-area indices. Timothy swards had higher leaf-area indices than meadow-fescue swards between April and mid-July, the period in which maximum values were recorded. N significantly increased the leaf area per g of leaf (leaf-area/leaf-weight ratio) at the beginning of the experiment, but not thereafter; the effect of cutting on this ratio varied with the date of cutting. Leaf areas per g of leaf were similar for the 2 species at the beginning and end of the experiment, but in mid-summer values for timothy increased whilst those for meadow fescue decreased. The relationship between leaf-area index and yield of dry matter is discussed.     

THE VOLUNTARY INTAKE OF DIPLOID (S22) AND TETRAPLOID (TETILA TETRONE) ITALIAN RYEGRASS, AND WHITE CLOVER BY SHEEP

Two experiments were conducted to measure the voluntary intake and digestibility of (a) primary growth and (b) regrowth of diploid (S22) and tetraploid (Tetila tetrone) varieties of Italian rye-grass (Lolium muitifiorum): Sl00 white clover (Trifolium repens) was included as an additional treatment in the second experiment with the re-growth herbage diets. Mature adult wether sheep, housed indoors in digesdhility crates, were fed individually on fresh herbage cut daily from late April to early June (primary growth) and in early Septemher (regrowth). The yield, digestihility, nitrogen and soluble–carhohydrate contents of the two ryegrass varieties were similar during the primary growth stage. Intake-digestibility relationships for the graces were positive, linear and different (P=0.05). The voluntary intake of diploid ryegrass was approximately 14% higher than that of tetraploid ryegrass of the same digestibility. With regrowth herbage the digestibility and voluntary intake of white clover was higher than both the Italian ryegrasses. The digestihility of the regrowth tetraploid was 6% units higher than the diploid variety, but there was no difference in the voluntary intake of digestible organic matter between the varieties at the regrowth stage. The intake of regrowth herbage was higher thaa that of primary growth herhage of similar digestihility.     

EFFECTS OF METHOD OF ESTABLISHMENT ON TALL FESCUE AND ITALIAN RYEGRASS MIXTURES IN THE FOLLOWING YEAR

Tall fescue and Italian ryegrass mixtures react differently to management in the year of sowing. The decrease in yield of tall fescue and the increase in growth of red clover, caused by the use of a cover crop, was still evident in the following year. In both the spring grazing and total yield of the first harvest year, the Italian ryegrass/ white clover mixture was better than the tall fescue/white clover mixture when a cover crop was used. The reverse trend was recorded when the grass plus clover was sown without the cereal. In general, the addition of red clover to the tall fescue/ white clover, or Italian ryegrass/white clover mixture, increased the yield, but the magnitude of the increase was modified by management during establishment. The increase in total herbage yield and the reduction of white clover growth due to nitrogen application were both related to management in the year of sowing. Consideration should thus be given to method of establishment in the assessment of herbage seeds mixtures.     

EFFECT OF SOME GREEN-CROP-DRYING PROCESSES ON THE DIGESTIBILITY AND VOLUNTARY INTAKE OF HERBAGE BY SHEEP

The effect of artificial drying under commercial conditions on the digestibility and voluntary intake of herbage by sheep was studied, using either van den Broek (900°C inlet temperature) or Swiss Combi (1100°C inlet temperature) triple-pass drum-type driers. Organic-matter digestibility of chopped dried herbage was 8·3, 5·8 and 5·3% lower than that of fresh herbage in Experiments 1, 2 and 3, respectively. Packaging chopped dried grass into ‘cobs’ caused a further reduction in OM digestibility of up to 2·8%. Pre-milling plus packaging (i.e. ‘pelleting’) depressed OM digesti bility of chopped dried grass by 5 to 6 percentage units. Digestibility of dried grass in its various physical forms was further reduced when offered ad lib.; the greatest fall (9·4%) occurred with pellets and the smallest fall (0·8?1·3%) with loose chopped material; cobs were intermediate at 4·3?7·0%.     

THE VOLUNTARY INTAKE AND DIGESTIBILITY BY SHEEP OE LEAF AND STEM FRACTIONS OF LOLIUM PERENNE

The leaves of tropical grasses are eaten in larger quantities than stems of similar DM digestibility. To determine whether the same fact applied to a temperate grass, studies were made with leaf and stem fractions of Lolium perenne. The leaves of L. perenne had a 20% higher voluntary intake than the stems, white the DM digestibilities were only slightly higher (67·3%ν. 64·8%). The leaves also had a larger surface area/g, a higher initial (12 h) fermentation rate in vitro, larger content of pepsin-soluble DM, and a smaller energy require ment to grind I g DM in a laboratory mill compared with the stems. The difference in voluntary intake between the leaves and stems of L. perenne was smaller than that for a number of tropical grasses.     

A COMPARISON OF THE EFFECT OF ITALIAN RYEGRASS AND TALL FESCUE MIXTURES ON THE FOLLOWING CROPS OF KALE AND BARLEY

The effects of preeropping with Italian ryegrass and tall fescue mixtures on marrow-stem kale (1st test crop) and barley (2nd test crop) were measured. Application of N to the grass/clover swards reduced the yield of DM, P, K, Na, Mg, crude protein and also the percentage crude protein in the kale test-crop. Following the tall fescue swards, the yield of DM, P, Na, Ca, Mg and E, crude protein and percentage crude protein in the kale were lower than after the Italian ryegrass swards. These effects were particularly evident in the kale stem. Interactions occurred which involved the method used to establish the herbage mixtures, the application of N to the swards and of fertilizers to the kale. These effects were complex, but the method of sward establishment could clearly affect the following kale crop grown several years later. The influence of grass swards on the second test-crop (spring barley) was much smaller than on kale. Precropping with Italian ryegrass or using a cover crop during grassland establishment reduced 1000-grain weight of barley. The crude protein percentage in barley grain was reduced by the compound fertilizer applied to the previous kale crop, particularly when no cover crop had been used during establishment of the herbage mixtures. The converse of these effects was recorded in the crude-protein percentage of the straw of the barley test-crop.     

THE ENERGY RETENTION OF LAMBS GRAZING S37 COCKSFOOT, S23 RYEGRASS AND S24 RYEGRASS AT LOW GRAZING PRESSURE

A grazing experiment to measure the feeding values of 4-week-old regrowths of S37 cocksfoot, S23 ryegrass and S24 ryegrass is described. A low grazing pressure was maintained on the pastures to ensure that animal production was not limited by herbage availability. Each sward was grazed by a group of 12 lambs under "worm-free" conditions. Increases in empty body weight, dry body weight and energy were measured by the comparative slaughter technique.
The liveweight gain of the cocksfoot-fed lambs was the same as the ryegrass-fed groups during the first half of the experiment but was lower in August and September. The final liveweight gains on S23 and S24 ryegrass were 14% higher than on S37 cocksfoot, but in terms of energy retention S23 ryegrass was 18% and S24 7% better than S37 cocksfoot. Digestibility measurements of herbage cut from the plots being grazed showed a positive correlation with energy retention by the lambs. Energy retention was negatively correlated with the proportion of acetic acid in the rumen adds, a fraction which was itself correlated with the soluble carbohydrate content of the herbage, but not with the digestibility of the herbage.
When interpreting animal-production results, intake, digestibility and rumen volatilc-fativ-acid proportions, should be taken into account. Because of the inadequacy of present methods of estimating the herbage intake of grazing animals, measurement of body-energy gains is not justified and empty-liveweight gains are sufficiently precise to measure relative energy retentions at pasture.     

A COMPARISON OF THE HERBAGE YIELD OF ITALIAN RYEGRASS AND TALL FESCUE MIXTURES IN THE SECOND AND THIRD YEAR AFTER SOWING

The annual yield of tall fescue was higher than that of Italian ryegrass in the third year after sowing, but the total yield of herbage from grass plus clover swards was similar.
In both the second and third year after sowing, the yield of herbage in the spring grazing was higher when fescue was used as the sown grass. The method of establishment of both tall fescue and Italian ryegrass affected the total and seasonal yield in the second and third year after sowing, but the magnitude of these effects was not nearly as marked as it was earlier in the life of the leys. In the second year after sowing, swards of both Italian ryegrass and tall fescue had a higher yield of total herbage and of white clover, and a lower ingress of unsown species, when established without a cover crop and grazed frequently in the year of sowing.
The inclusion of red clover did not increase total yield of DM in the second and third year after sowing, and it slightly decreased the yield of the tall fescue mixture in the third year following sowing when N was applied. S170 tall fescue was readily grazed by sheep in spring and autumn.
The apparent recovery of applied N varied with the mixture sown, and the management given during establishment.     

THE HERBAGE CONSUMPTION AND MILK PRODUCTION OF COWS GRAZING S24 RYEGRASS AND S37 COCKSFOOT

Pure stands of S24 ryegrass and S37 cocksfoot were grazed by groups of 6–8 cows for 5 periods spread over 3 years. Three periods were in the spring and two in the summer. The ryegrass was 4–5 percentage units more digestible than the cocksfoot and generally contained more soluble carbohydrate. In the spring periods, the organic-matter intakes and milk yields of the cows were much the same for the two herbage species, but in the summer they were both higher for the ryegrass. There were no important differences in milk composition due to herbage species, or in the liveweight changes of the cows.     

EFFECTS OF NITROGEN FERTILIZATION OF MIXED SWARDS ON HERBAGE YIELD, DRY MATTER DIGESTIBILITY AND VOLUNTARY FOOD INTAKE OF THE CONSERVED HERBAGES

In 2 experiments nitrogenous fertilizer was applied at 3 levels (0, 46 and 92 lb N/ac) to a permanent pasture and a ryegrass/clover ley and the swards were harvested before ear emergence and conserved as either artificially dried grass or tetrapod hay. Apparent dry matter digestibility and voluntary food intake of the conserved herbages were measured with sheep.
N caused a small but significant depression in apparent DM digestibility but did not affect voluntary food intake. It increased yields of DM and digestible DM significantly.
The DM digestibility and voluntary food intake of hay were always significantly lower than those of the corresponding dried grass. Voluntary food intake of all fodders was directly related to herbage digestibility and inversely related to herbage crude fibre content.     

A HISTORY OF THE INTRODUCTION OF TIMOTHY AND COCKSFOOT INTO ALTERNATE HUSBANDRY IN BRITAIN. 1. THE YEAR 1763 AND ITS SIGNIFICANCE

Timothy ( Phleum pratense ) and cocksfoot ( Dactylis glomerata ), although indigenous and commonly distributed, found no place in alternate husbandry in Britain until the end of the eighteenth century. Their value was then discovered as an indirect consequence of the search by the London Society of Arts for plants able to grow during the 'dead season' of the year. Letters on the subject were addressed by the society to Europe, Asia, North America and to people at home, but with no positive results. There was, however, in the New England provinces of America a developing enthusiasm at that time for timothy and, although not a winter grower, its merits became a matter for correspondence and discussion within the Society. A consequence was the arrival from America early in 1763 of various lots of seeds, but without any information as to sender(s) or the species. Both timothy and cocksfoot must have been received, for each were sown later that year at Walham Green, London, and the optimism and controversy regarding them led ultimately to a recognition of their worth and place in ley farming. The earliest sowing of American timothy in England occurred in 1743, but was without influence on agricultural thinking.
Reference is made to the introduction of European species into North America, and also to the Georgical Committee set up in 1664 by the Royal Society.     

THE EFFECT OF TIME OF CUTTING ON EAR PRODUCTION AND SEED YIELD IN S.48 TIMOTHY

After uniform defoliation in February, spaced plants of S.48 timothy were cut on one of 12 fortnightly dates, starting at the end of March.
Analysis of the herbage removed at each cut showed an increase in plant and unit tiller weight throughout the season, but a decline in the number of tillers, especially before the beginning of shooting.
The date of ear emergence was not affected by cutting up to 5 May and only slightly delayed in plants cut on 19 May. Plants treated subsequently flowered much later but after a fairly constant interval following defoliation.
Cutting on and after 7 April depressed fertile tiller formation with increasing severity, until only vegetative tillers appeared in the recovery growth following treatment at the beginning of August.
Seed yield per plant declined with the decrease in fertile tiller numbers, but after the early cuts some compensation by production of slightly more seed per ear was recorded.
The results are discussed in terms of the physiological transition of the plant towards flowering.     

THE USE OF LIGHT INTERCEPTION, GROSS MORPHOLOGY AND TIME AS CRITERIA FOR THE HARVESTING OF TIMOTHY, SMOOTH BROME AND COCKSFOOT

An experiment was designed to compare morphological development, light interception and time interval as possible criteria for the defoliation of timothy, brome-grass and cocksfoot. The morphological criterion included: (a) a first harvest before stem elongation and a second harvest after initiation of axillary bud development at the base of each tiller (b) a harvest immediately after stem elongation. Light was compared on the basis of 95 % and 80 % interception of the incident radiation by the foliage. Two-, 4- and 6-week intervals were used in the time series. Increased yields of up to 2600 lb DM/ac were obtained in timothy and bromegrass fertilized at 275 lb N/ac/yr when morphological treatment (a) was used in preference to (b); cocksfoot yields were not influenced. The greater the time interval between harvests or the greater the light interception before harvest, the greater was the yield. Advantages and disadvantages of the 3 criteria are discussed.