Ryegrass-dominant Pasture Research Articles

Birdsfoot trefoil - an alternative legume for New Zealand dairy pastures

Two grazing trials conducted with Friesian cows in mid lactation showed milk yields were higher on birdsfoot trefoil (Lotus corniculatus)-dominant pasture (19.8 and 16.7 l/cow/day) than on white clover-dominant (17.8 and 15.4 l/cow/day) or ryegrass-dominant (13.0 and 11.7 l/cow/day) pastures. Increased milk production on the Lotus and clover was attributed to the higher nutritive value of the legume-based pasture compared with the ryegrass, and to higher dry matter intakes. Cows grazing Lotus also had improved feed conversion efficiency compared with those grazing either ryegrass or clover, indicating that the presence of condensed tannins in the Lotus may have contributed to the improved efficiency. Milk protein concentration was consistently higher on the Lotus (3.36 and 3.35%) than on the ryegrass (3.15 and 3.21%) or clover (3.30 and 3.21%) in both experiments, while milk fat levels were lower in Experiment 1. While Lotus increased milk yield and milk protein concentration, its potential as a forage legume for dairy cows also depends on annual herbage production and the determination of how best to utilise it in a farm system. Keywords: birdsfoot trefoil, dairy cows, dry matter intake, Lotus corniculatus, milk composition, milk yield, perennial ryegrass, white clover

Carcass fatness in lambs grazing various forages at different rates of liveweight gain

Abstract In three experiments, Dorset, Suffolk cross, or Coopworth lambs weighing c. 30 kg in January were offered a range of forages including high-endophyte Nui ryegrass-dominant pasture, white clover-dominant pasture, Moata or Concord ryegrasses, lucerne, rape, or chicory. Herbage allowances were adjusted to achieve target liveweight gains of 300, 200, or 120 g/day and lambs slaughtered at c. 43 kg liveweight from March to May. In Experiment 1, medium and low rates of liveweight gain were compared on both ryegrass-dominant and clover-dominant swards. In Experiment 3, the comparison was extended to include a high rate of liveweight gain (300 g/day) on clover-dominant swards. Allowances of Nui ryegrass required to achieve liveweight gains of 200 g/day were over 2 times greater than that of clover and up to 5 times greater than for chicory and lucerne. There was no effect of liveweight gain on carcass GR measurements of lambs grazing ryegrass-dominant pastures when compared at the same carcass weights but...

Early summer pasture control: what suits the plant?

Plugs of sheep-grazed, ryegrass-dominant pasture were transplanted to a glasshouse, in order to make detailed studies of tiller appearance from the base of flowering tillers in late spring-early summer. In 2 experiments, cutting treatments which reduced the opportunity for transport of assimilate from parent flowering tillers to daughter tillers markedly reduced both numbers of daughter tillers formed and their size. In one of the studies, proportion of radioactive carbon dioxide fed to flowering tillers, but recovered from daughter tillers, was 7.0%, and this transported radiocarbon appeared to be delivered preferentially to leaf elongation zones of young tillers. There appear to be fundamental differences in tillerbehaviour between 'Grasslands Ruanui' ryegrass and 'Ellett' ryegrass. The implications for farm practice are briefly discussed. Keywords ryegrass, tiller dynamics, radiocarbon, summer pasture production, pasture persistence

CHANGING SEASONAL GROWTH OF PASPALUM PASTURES BY OVER-DRILLING RYEGRASS AND WHITE CLOVER CLOVER

Volunteer summer-growing paspalum is often present in dairy pastures of northern New Zealand. When paspalum becomes the dominant grass winter/spring pasture production is reduced. This creates management problems on seasonal dairy farms because cow feed requirements and milkfat production are highest in winter/spring. This paper gives data from a current experiment at Ruakura Agricultural Research Station in which Roundup herbicide was used to provide a competitlon-free environment for the overdrilling of cool-season pasture species. Herbicide rates of 6, 4, 2 and 0 l/ha were applied in autumn 1965 before overdrilling a mixture of Ellett ryagrass and Grasslands Kopu white clover. A fifth treatment was the original pasture which was not sprayed or overdrilled. High rates (4-6 I/ha) of Roundup completely elimmated paspalum from the pasture and immediately reduced the white clover to a low proportion (less than 10% of dry matter). The sprayed and overdrilled pastures have remained ryegrass dominant over the duration of the experiment. In 1985 and 1966, winter/spring production from the new ryegrass dominant pastures were significantly better than from the original paspalum dominant pasture. The implications of the noticeable increase in paspalum in the renewed pastures are discussed. Keywords: pasture renewal, pasture renovation, Roundup herbicide, pasture botanical composition, seasonal pasture productlo".

THE INFLUENCE OF SPRING GRAZING MANAGEMENT ON PASTURE QUALITY

Six grazing treatments, consisting of an intensity comparison (hard, medium and lax) at a 14.day regrowth interval, and a frequency comparison (regrowth intervals of 7, 14, 21 and 26 days) at the medium intensity, were imposed over 12 weeks during spring (treatment period). Subsequent pasture performance was assessed over a further 12 weeks during summer (post-treatment period). By the end of the treatment period two groups of wards were apparent. Compared with the other wards. Lax and Medium swards at regrowth intervals of 21 and 26 days were characterised by greater total, green, ryegrass reproductive stem and dead herbage mass and lower proportion of leaf. During the post-treatment period reproductive stem senesced and these wards contained greater levels of dead herbage. These swards also had lower leaf accumulation during the treatment period, though leaf accumulation was lower only on lax grazed swards during the post-treatment period. On high-fertility, ryegrass-dominant pastures hard grazing was not required to maintain pasture quality, as this occurred also under the medium grazing intensity (residual sward height 6-6 cm) provided the interval between grazing was 14 days or less (pregrazing ward height of 20 cm). It may be expected that herbage intake and animal performance on lax and infrequently (21 and 26 days) grazed swards would be reduced because of both lower leaf accumulation and greater dead herbage mass especially over the summer. Keywords: Pasture quality, ward characterisics, grazing frequency, grazing intensity, leaf accumulation, herbage mass.

The effect of height of pasture and concentrate composition on dairy cows grazed on continuously stocked pastures

SummaryThe effects of pasture height and of a cereal-based concentrate or a sugar-beet pulp supplement were studied with 30 spring-calving cows on continuously stocked, perennial ryegrass dominant pasture in a 3 × 3 latin-square design with periods of 4 weeks. Pastures were maintained at heights of about 5·0 cm (short) or 6·5 cm (control). On the short pasture, the two supplements had similar effects and were additive but on the control pasture, compared with sugar-beet pulp, the cereal concentrate depressed herbage intake. Average fat-corrected milk yields were 26·3 and 28·1 kg/day on short and control areas respectively. Both supplements increased milk yields by about 0·7 kg per kg OM supplied. Cows on the short pasture tended to lose weight. Supplements slightly increased live weight and sugar-beet pulp tended to increase body condition score. In observations continued after the conclusion of the main experiment the short pasture was more productive and of slightly higher nutritive value. Cows receiving the concentrate supplements increased total intake but this was reflected only in live weight. The total utilized metabolizable energy for the whole season was about 130 GJ/ha.

CHEMICALS FOR PASTURE RENOVATION AND IMPROVEMENT OF HERBAGE QUALITY

Research into chemical pasture renovation was pioneered by NZ scientists in the 1960's but the technique was not widely adopted at that time. Subsequent work has confirmed that white clover (Jrifolium repens L.) is a poor competitor against browntop (Agrostis capillaris L.) for phosphate. This has implications regarding nitrogen fixation. Pasture renovation also provides an opportunity to introduce preferred pasture grasses, free of competition from resident grass species. White clover is now recognised as a high-quality feed for livestock. Work is reviewed showing the correlation between liveweight of ewe hoggets and subsequent breeding performance and that white cloverdominant pasture was superior i0 ryegrass-dominant pasture for flushing breeding ewes. In field-scale testing, the plant growth regulator mefluidide suppressed seedhead formation in pasture grasses and gave substantial, though regionally variable, liveweight gains in lambs, beef cattle and deer. In limited evaluation with dairy cows changes in pasture herbage have not been matched by improved milk or milkfat yield. Keywords: Chemical pasture renovation, fertiliser utilisation, pasture quality, chemical plant growth regulator

Effects of the timing and intensity of spring grazings on reproductive development, tillering, and herbage production of perennial ryegrass dominant pasture

Abstract Reproductive development, tillering, and herbage production were studied in mixed pastures containing ‘Grasslands Nui’ perennial ryegrass (Lolium perenne L.) and ‘Grasslands Huia’ white clover (Trifolium repens L.), which were rotationally grazed by sheep. The effects of interruption of ryegrass reproductive development during early culm elongation (TI) or 30% inflorescence emergence (T2), by either hard grazings (H; residual leaf area index (LAI) 0–0.7) or lax grazings (L; residual LAI 0.8–2.2) were compared. These grazing intensity treatments were continued until mid summer; and in late summer and autumn all pastures received the same grazing management. Culm elongation in an initial group of reproductive tillers, 2400/m2, started in October, and 30% inflorescence emergence occurred in mid November. During November and December a further 1000/m2 secondary reproductive tillers appeared. Few new reproductive tillers appeared after December. Vegetative ryegrass tiller density declined markedly dur...

Use of residual leaf area index and light interception as criteria for spring-grazing management of a ryegrass-dominant pasture

Abstract Detailed measurements of herbage accumulation were made on a ‘Grasslands Nui’ perennial ryegrass (Lolium perenne)-dominant, ‘Grasslands Huia’ white clover (Trifolium repens) pasture under 4 late spring grazing intensities, based on residual leaf area index (LAI), and 2 grazing frequencies based on light interception. Lax grazing during late spring (residual LAI 0.9–3.0) resulted in rank stalky herbage, whereas hard grazing (residual LAI 0.1–0.9) resulted in more leafy herbage and higher ryegrass tiller density. For the 46 weeks of the experiment, 16.5 and 14.61 DM/ha accumulated with hard and lax spring grazing respectively. During autumn, delaying grazing until 2 weeks after 95% light interception markedly increased green herbage accumulation compared with grazing at 95% light interception, without significantly reducing ryegrass tiller density or white clover content. It is concluded that in spring, in contrast to other seasons, management of ryegrass-dominant pasture to control reproductive de...

GRAZING MANAGEMENT OF PERENNIAL RYEGRASS/ WHITE CLOVER PASTURE IN-LATE SPRING

The patterns of herbage accumulation and the tiller dynamics of a "Grasslands Nui" perennial ryegrass dominant pasture were compared under two grazing intensity treatments in late spring. Rank stemmy herbage developed with lax grazing whereas dense leafy pasture developed with close grazing. Dead herbage and uneaten stems in rank pastures shaded photosynthetic tissue. Leafy swards had a higher herbage accumulation rate and a higher tiller density than stemmy swards. Methods of achieving leafy pasture on farms by combinations of hard grazing, forage conservation and mechanical topping are discussed briefly.

A COMPARISON OF PASTURE RECOVERY FOLLOWING DIFFERENT GRAZING INTENSITIES WITH AND WITHOUT NITROGEN APPLICATION

Ryegrass-dominant pasture was differentially grazed in May 1975, and recovery of heavily and laxly defoliated swards compared over a 6-week growth period

Pithomyces chartarumspore distribution and sheep grazing patterns in relation to urine-patch and inter-excreta sites within ryegrass-dominant pastures

Abstract Pithomyces chartarum spore loads were determined on samples of dead ryegrass leaf taken from the base of grazed ryegrass-dominant pastures. Spore loads were significantly higher on samples from urine-patch than from inter-excreta areas. Results from a small grazing experiment indicated that under rotational grazing, sheep ingested little of the inter-excreta herbage before most of the available urine-patch herbage had been removed.

Influence of the grazing animal on distribution patterns of saprophyticFusariumspecies in a ryegrass pasture

Abstract Fusaria spore populations on herbage from grazed ryegrass-dominant pastures were determined. Spore loads were markedly higher on herbage from urine patches than on herbage from inter-excreta sites. Within urine patches there was a higher spore load on dead material resulting from urine scorch than on other dead material within the growth-response zone. Profile and component sampling indicated that Fusaria spore distribution patterns were similar to those previously found for spores of Pithomyces chartarum (Berk. & Curt.). M. B. Ellis.

Induction and prevention of ryegrass staggers in grazing sheep

Abstract An experiment during the summer and autumn of 1970–71 showed that ryegrass stae-gers was induced in sheep that were forced to graze the base of ryegrass-dominant pastures. These sheep ingested significantly more dead material than did unaffected sheep which were prevented from grazing the base of the pasture.

Moulds on leaves of perennial ryegrass and white clover

Abstract Moulds demonstrable by routine culture techniques on leaves of pasture plants were examined to assess the incidence of toxinogenic groups. Perennial ryegrass, white clover, and litter from ryegrass–dominant pasture were collected regularly for 2 years from sites in the Waikato basin. Numbers of moulds were highest on litter, lower on ryegrass leaves, and lowest on clover. Numbers were greater in paddocks being grazed than in those from which stock were excluded. The most commonly recovered groups were, in approximate order of frequency, pycnidial forms; Cephalosporium spp.; Cladosporium herbarum; Fusarium spp., in particular F. nivale’, Colletotrichum spp.; Rhyncosporium spp.; Verticillium spp.; Myrothecium spp.; Pithomyces chartarum, and Metar–rhizium anisopliae. F. nivale and two groups of Cephalosporium were virtually restricted to ryegrass leaves and litter, and Verticillium spp. and M. anisopliae to clover leaves; other groups were common to all types of substrate. The litter flora was quali...

Comparison of the weight gain and the composition of blood and saliva in sheep grazing timothy and ryegrass swards.

1. After a preliminary period of 2 weeks indoor feeding on hay, two groups of wethers grazed either a timothy pasture or a ryegrass-dominant pasture for 12 weeks. The timothy was particularly low in sodium and chlorine.2. Within a week of turning out, saliva sodium fell and potassium increased in the timothy group, and by the end of the experiment, the sodium: potassium ratio was 1.9:1. The changes in saliva were not reflected in blood composition. The rate of live-weight gain was similar in both groups of sheep.3. The results confirm those of a previous indoor experiment and show that timothy supplies insufficient sodium to maintain the normal saliva composition of sheep.

An examination of ergot in relation to ryegrass staggers.

Abstract Extract Ryegrass staggers is a sporadic disease condition of farm animals grazing ryegrass-dominant pastures in New Zealand, prevalent in summer or autumn when there is sufficient moisture to provide some growth of the ryegrass. The disease is characterized by a condition of temporary tetanic muscle spasm, usually after a period of brisk exercise. There is no satisfactory treatment for the disease and its cause is unknown although the causal agent is regarded as being present in the pasture herbage (Armstrong, 1956; Cunningham & Hartley, 1959).

Growth of Ryegrass-dominant Pasture grazed by Cows, and Properties of New Zealand Butterfat

MARKED and regularly recurring seasonal fluctuations in the characteristics of New Zealand butterfat have been reported by Cox and McDowall1. The iodine value, for example, rises to a maximum of about 41 in mid-winter, falls gradually until the beginning of October and then rapidly during October and November to a mid-summer minimum of about 34, and rises again during the autumn and early winter to the mid-winter maximum. The carotene and vitamin A contents of the butterfat also have been shown by McDowell and McDowall2 to change according to a regular seasonal pattern, with maximum values in the early spring and minimum values in mid-summer. These latter changes have been found by McGillivray3 to be a reflexion of changes in the carotene and vitamin A contents of the blood plasma.

The intensive production of herbage for crop-drying III. The effect of the continued application of nitrogenous fertilizers to grassland

1. The experiment previously described (series 4, Holmes, 1949) on the effect of massive applications of nitrogenous fertilizers on the productivity of a ryegrass dominant pasture was continued for 3 years (1946, 1947, 1948). The manurial treatments ranged from none to the application of 312 lb. nitrogen per acre and this was applied with and without 135 lb. P2O5 and 168 lb. K2O per acre. Farmyard manure was applied to one block in 1948.2. With the heaviest nitrogen treatment plus phosphate and potash the average yield for 3 years was 8000 lb. dry matter and 1640 lb. crude protein (similar to the yield in 1946) compared with a control yield of 4720 lb. dry matter and 590 lb. crude protein. The yields declined from year to year when phosphate and potash were not applied, the decline being greatest with the heaviest application of nitrogen.3. The seasonal distribution of the yield of herbage was very considerably modified by the time when fertilizers were applied.4. The botanical composition of the swards was related to the yield, 70% of the grasses in the highest yielding sward being perennial ryegrass and cocksfoot while the lowest yielding sward contained only 35% of these grasses.5. The manurial treatments had no effect on the pH, loss on ignition or the content of readily soluble P2O5 in the soil, but in the first year there was some evidence of a general reduction of readily soluble K2O to a low level.

Studies in grazing management I. A comparison of the production obtained from close-folding and rotational grazing of dairy cows

1. An experiment was carried out from 3 May to 10 October 1949 to compare close-folding with rotational grazing of dairy cows. With close-folding the cows were moved daily to an area of fresh pasture which was calculated to supply the day's feed requirements; the rate of stocking ranged from 50 to 80 cows per acre. With rotational grazing the cows were stocked on pasture at the rate of 6–8 cows per acre and moved from one pasture to another at intervals of 5–14 days. Two uniform groups of Ayrshire cows were used, and each group spent a period on each system of grazing. Two pastures, a ryegrass-dominant old pasture and a cocksfoot-dominant ley, were used, and as far as possible the pasture grazed by both groups of cows was similar. Nitrogenous top dressings up to 104 Ib. nitrogen per acre in the season were applied uniformly to both the close-folding and rotational areas. No supplementary feeding was given to the cows.2. The best methods of close-folding practised gave 215 and 201 cow-days of grazing per acre with 550 gal. milk per acre from the cocksfoot ley and 582 gal. from the permanent pasture. Rotational grazing on the same two pastures gave 181 and 138 cow-days and 450 and 351 gal. milk per acre respectively.