More feed for New Zealand dairy systems

2001 ◽  
pp. 283-288 ◽  
Author(s):  
D.A. Clark ◽  
C. Matthew ◽  
J.R. Crush
Keyword(s):  
New Zealand ◽  
Plant Breeding ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Crude Protein ◽  
Plant Stress ◽  
Net Photosynthesis ◽  
Potential Yield ◽  
C3 Plant ◽  
Upper Limit

An upper limit to productivity of perennial ryegrass-white clover pastures in New Zealand at about 15 t DM/ha per year has been identified as a constraint to future increases in productivity. With potential yields of 26.6 t DM/ha per year from temperate grasses and 45 t DM/ha per year from maize at mid-latitudes, the challenge for New Zealand dairy farming systems is to achieve greater than 15 t DM/ha per year without imposing additional production or environmental costs. Given these constraints a major switch to crops is not feasible because those that produce more than pasture, e.g., maize, have insufficient crude protein to support lactation. Theoretically, a farm area allocation to 78% perennial ryegrass-white clover and 22% maize-winter oats could provide 23.3 t DM/ha per year at a crude protein content of 16%. This is greater than the 20 t DM/ha per year upper limit of irrigated perennial ryegrass-white clover. Incremental yield improvements of grasses and clovers by traditional plant breeding are low (1.5% per year), and difficult to capture. Future plant breeding gains are more likely to come from increased plant stress tolerance. Improved pasture monitoring to allow timely removal of constraints, will enable potential yields to be achieved. Biotechnology offers the possibility of improving the potential yield of net photosynthesis by 20% either through the transfer of genes from a C4 plant (e.g., maize) or a C3 plant (e.g., perennial ryegrass), or use of the major photosynthetic enzymes, rubisco, from a thermophilic alga. Biotechnology is also providing new knowledge about the control of plant development and response to stresses. The application of this knowledge may allow dairy farmers to achieve another 5 t DM/ha per year from perennial ryegrass-white clover pastures. Keywords: biotechnology, dairy, perennial ryegrass, photosynthesis, white clover, yield limitation

Effects of initial sowing rate and subsequent grazing management on the growth and clover content of irrigated white clover - perennial ryegrass swards in northern Victoria

2005 ◽  
Vol 45 (12) ◽  
pp. 1595 ◽  
Author(s):  
K. B. Kelly ◽  
C. R. Stockdale ◽  
W. K. Mason
Keyword(s):  
Dairy Cows ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Crude Protein ◽  
Net Photosynthesis ◽  
Grazing Management ◽  
First Year ◽  
General Decline ◽  
Clover Content ◽  
Pure White

Two experiments were conducted over 3 years. One was of factorial design involving 2 sowing rates of white clover (Trifolium repens L. cv. Haifa; sown at 8 or 3 kg/ha) and perennial ryegrass (Lolium perenne L. cv. Grasslands Nui; sown at 5 or 15 kg/ha) grazed by dairy cows at 2 frequencies [frequent (2–3 weeks in spring/autumn) and infrequent (4–6 weeks in spring/autumn)] and 2 intensities [hard (residual rising plate meter heights of less than 4 cm) and lax (residual rising plate meter heights of more than 5 cm)]; and the second was a regression design involving 5 sowing rates of white clover and ryegrass ranging from pure clover to pure ryegrass (sown at 10/0 through to 0/20 kg/ha), all grazed frequently and at a hard intensity. The hypotheses tested were that (1) pure white clover swards would be at least as productive as those that contained ryegrass, and (2) more frequent grazing would result in greater quantities of DM removed, while hard grazing would maintain a higher clover content. In general, the hypotheses were confirmed. Over the 3 years of the experiments, pure white clover swards were at least as productive as mixed swards in a situation where no nitrogen fertiliser was applied. In the first year, the amount of DM removed declined (P<0.05) as the ryegrass sowing rate increased, but by year 3, the pure clover treatment out-yielded the other treatments. Except for the first year, frequent grazing resulted in more (P<0.05) DM removed than did infrequent grazing. Frequently grazed swards also had higher daily net photosynthesis after grazing than did the swards in infrequently grazed treatments, and achieved maximum levels of photosynthesis more quickly. There was no difference in photosynthesis rate, despite significant differences in clover content, between sowing rate treatments, regardless of grazing management. Initial sowing rate had a large effect on clover content in year 1, but by year 3, most of this had disappeared as clover contents rapidly converged. Frequency of grazing had its greatest effect on clover content in year 1, with infrequent grazing resulting (P<0.05) in the greatest clover contents. Grazing intensity was an important determinant of clover content in years 2 and 3, where hard grazing resulted (P<0.05) in higher clover content. Digestibility of the herbage on offer ranged from 65 to 80%, and crude protein concentrations varied from 12 to 26%. In general, frequent grazing resulted in a digestibility of 2–4 percentage units higher than infrequent grazing, with hard grazing also tending to increase digestibility. Hard grazed treatments always had high crude protein concentrations in the herbage present before grazing, and there was a slightly higher concentration in frequently grazed herbage compared with herbage that was grazed less frequently. The white clover–perennial ryegrass swards generally responded best to a combination of frequent and hard grazing. However, neither white clover nor perennial ryegrass appears to be well adapted to the combination of soils, climate, irrigation and grazing by dairy cows that occurs in the northern irrigation region of Victoria, as evidenced by a rapid influx of weeds and the general decline in productivity over the duration of the experiment.

THE DEVELOPMENT OF OUR PASTURE PLANT RESOURCES: THEN AND NOW

1987 ◽  
pp. 89-92
Author(s):  
Robert Burgess
Keyword(s):  
New Zealand ◽  
Plant Breeding ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Pasture Grass ◽  
Ecotypic Differentiation ◽  
Breeding Objectives ◽  
Improved Cultivars ◽  
Pasture Plant ◽  
Improved Pasture

This paper honours the contribution of the E.S. Levy to the development of improved pasture plant cultivars in New Zealand by reviewing his work on ecotype development within herbage species. Starting in the late 19209, Levy compared at a single site many thousands of seed lines of pasture grass and legume species collected from both within New Zealand and overseas. In several species, including perennial ryegrass, white clover, red clover, cocksfoot and subterranean clover, he showed the existence of genetically distinct strains (ecotypes) which he claimed had developed under the farming practices, climate and soil fertility in their areas of origin. This work led to the enunciation of pasture plant breeding objectives, the development of improved pasture cultivars and a strategy for grassland improvement. This wes based on permanent pasture Hawke's Bay perennial ryegrass and New Zealand No. 1 white clover, bred for use in high production forage systems throughout New Zealand. The breeding objectives rejected by Levy, such as the development of improved cultivars for low production systems, must be reconsidered in view of today's changed environment for pastoral farming. Keywords: ecotypic differentiation, evolution, improved cultivars, plant breeding objectives.

Effects of season and time since defoliation on the nutritive characteristics of three irrigated perennial pasture species in northern Victoria 1. Energy, protein and fibre

1999 ◽  
Vol 39 (5) ◽  
pp. 555 ◽  
Author(s):  
C. R. Stockdale
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Crude Protein ◽  
Energy Content ◽  
Energy Concentration ◽  
Neutral Detergent Fibre ◽  
Plant Parts ◽  
Metabolisable Energy ◽  
Grazing Dairy Cows

The study reported here compared the nutritive characteristics of the 3 most common irrigated perennial pasture species grown in northern Victoria as they regrew after defoliation at various times during the year. In addition, the relative influence of changes to the proportions of morphological components and the nutritive characteristics of the individual components on the quality of whole plants was examined. The nutritive characteristics of white clover (Trifolium repens cv. Haifa), ryegrass (Lolium perenne cv. Ellet) and paspalum (Paspalum dilatatum) were examined at weekly intervals on 4 occasions during spring–autumn, 1993–94. On each occasion, pastures were defoliated with a drum mower and allowed to regrow for up to 9 weeks; defoliation dates were 24 September, 26 November, 28 January and 25 March. The variation in estimated metabolisable energy [obtained from in vitro dry matter (DM) digestibility], crude protein and detergent fibre concentrations within species was significantly (P<0.01) less than between clover and the grasses. White clover was consistently high in metabolisable energy (9.3–11.2 MJ/kg DM) and crude protein (17.7–27.7% DM), and low in neutral detergent fibre (27.8–39.8% DM) in all periods. At the other extreme, paspalum had a metabolisable energy content that peaked at 9.3 MJ/kg DM, and fell as low as 7.4 MJ/kg DM. Paspalum also had low protein (7.5–14.7% DM) and very high neutral detergent fibre (61.9–69.9% DM) concentrations. Ryegrass varied greatly in metabolisable energy concentration between the 4 periods, being high in autumn (average of 10.2 MJ/kg DM) and low in summer–autumn (average of 8.4 MJ/kg DM). Metabolisable energy apart, there were few differences in the crude protein and detergent fibre contents of ryegrass and paspalum. Perennial ryegrass is generally considered a superior feed to paspalum, but the data indicate this is not always the case under irrigation in northern Victoria. The nutritive characteristics of the plant fractions (leaf, stem, dead, inflorescence) were analysed separately to give an indication of the limits to selection by grazing cows. Differences in metabolisable energy between leaf and stem in both white clover and perennial ryegrass suggested that grazing dairy cows could consume a pasture diet which is likely to be slightly higher in energy than that in the herbage on offer. With paspalum, this is unlikely to be the case because differences in energy content between plant parts were small. However, with all species, cows should be able to consume herbage that is significantly higher in protein, and lower in detergent fibre, than that on offer because of differences in their concentrations in leaf and stem. The nutritive characteristics of morphological components of each species remained relatively constant throughout the study. Therefore, it would seem that it is the proportions of these fractions in the plant, together with severity of grazing, that will largely determine the degree of selection that can occur.

scholarly journals Plant responses to climate and relationships with pasture persistence

2011 ◽  
Vol 15 ◽  
pp. 99-107
Author(s):  
D.F. Chapman ◽  
G.R. Edwards ◽  
Z.N. Nie
Keyword(s):  
Plant Breeding ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Climatic Factors ◽  
Insect Pest ◽  
Plant Responses ◽  
Negative Effects ◽  
Term Survival ◽  
Variable Environment ◽  
Resource Limitations

Relationships between climatic factors and persistence of grazed perennial ryegrass and white clover pastures in New Zealand are reviewed from an ecophysiological perspective. 'Persistence' is defined in terms of physical survival of plants of sown cultivars: the effects of climate on plant populations are considered. Substantial information is available on the population dynamics of perennial ryegrass and white clover in different climatic environments, particularly on the influence of drought on populations. Substantial, direct negative effects of drought on the density of perennial ryegrass tillers and white clover stolons have been recorded, though populations have generally recovered after release from drought conditions. Otherwise, the effects of climaterelated resource limitations on population size are more likely to be interactive, working in concert with other factors such as management, soil fertility and insect pest challenges to limit the capacity of homeostatic responses to restore the optimal (for long term survival) balance between above- and below-ground resources. The relative extent to which more recent cultivars of perennial ryegrass are able to tolerate multiple, simultaneous resource limitations compared to older cultivars (with different phenotype) is considered, but there is little direct evidence on this matter. Issues that should be considered in future pasture persistence research are identified and discussed. One of these concerns is the persistence of trait expression in cultivars bred for specific traits. More research on this topic is warranted, since molecular plant breeding techniques are strongly based on trait manipulation, and genotype x environment interactions can be expected in the spatially and temporally variable environment of grazed pastures. Keywords: drought, ecology, plant breeding, ryegrass, white clover

scholarly journals Liveweight changes in lambs grazing six perennial ryegrass cultivars

1999 ◽  
pp. 31-35
Author(s):  
C.T. Westwood ◽  
M.G. Norriss
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Moisture Stress ◽  
Botanical Composition ◽  
Independent Research ◽  
Ewe Lambs ◽  
Research Organisation ◽  
Clover Content

Liveweight changes were measured for lambs grazing six high endophyte perennial ryegrasses, in a grazing experiment run by an independent research organisation in Canterbury, New Zealand. Ryegrass cultivars were sown under code in a binary mix with white clover in February 1997. Plots were strategically irrigated to avoid moisture stress, and stocked at approximately 27 Coopworth ewe lambs per ha in May 1997. Common pasture residual mass was maintained across cultivars by strategic addition of extra lambs, with extra grazing days recorded for each replicate. Lamb liveweight gains and botanical composition of replicates were assessed quarterly. Lamb liveweight gains differed significantly between treatments in Years 1 and 2 of this ongoing 3 year study. Lambs grazing 'Quartet' tetraploid perennial ryegrass gained, on average, 37.4 kg and 36.1 kg liveweight during Years 1 and 2 respectively, and together with 'Aries HD' (35.0 and 35.9 kg) produced significantly greater liveweight gain compared with 'Grasslands Nui' (22.0 and 23.7 kg) and 'Bronsyn' (22.5 and 24.1 kg), LSD0.05 = 6.0 and 7.4. Lambs grazing 'Embassy' gained 31.6 kg and 28.7 kg, and 'Vedette' 29.8 kg and 28.0 kg. Extra grazing days expressed as a percentage of base grazing days were between 3.8 and 6.7% across cultivars for Year 1 and between 2.0 and 6.5% across cultivars for Year 2. This study demonstrated significant differences in animal productivity between perennial ryegrass cultivars that produce comparable yields of dry matter. Differences may reflect variation in forage quality, endophyte toxins, clover content in the sward or other unidentified cultivar characteristics. Keywords: digestibility, endophyte, lamb, liveweight, perennial ryegrass, tetraploid

Effect of sward height and its clover vertical distribution on the performance of cashmere goats grazing perennial ryegrass/white clover swards during the autumn

1997 ◽  
Vol 1997 ◽  
pp. 172-172
Author(s):  
M. del Pozo ◽  
K. Osoro
Keyword(s):  
New Zealand ◽  
Vertical Distribution ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Northern Spain ◽  
Sward Height ◽  
Cashmere Goats ◽  
The Vertical Distribution ◽  
Clover Pasture

Previous trials performed in temperate sown swards from New Zealand (Clark et al, 1982), from UK (del Pozo and Wright, 1995) and from Spain (Osoro and Martinez, 1995) showed improvements of sward clover contents on grass/clover pastures grazed by goats during the early part of the grazing season. However, this phenomenon might not occur to the same extent during autumn due to clover's poorer competitiviness with ryegrass. Additionally, Merchant and Riach (1994) showed that cashmere goats required pastures with mean sward heights to be above 6 cm to achieve aceptable levels of performance but were not able to considerate the implications of the sward legume content on their liveweight changes. The aim of this study was to investigate the effects of three contrasting sward height regimes and their associated relative changes in the vertical distribution of the sward clover proportion on the performance of cashmere goats grazing during the autumn season a lowland perennial ryegrass/white clover pasture located in Northern Spain.

Quantitative digestion of fresh herbage by sheep:V. The digestion of four herbages and prediction of sites of digestion

1979 ◽  
Vol 92 (3) ◽  
pp. 605-616 ◽  
Author(s):  
M. J. Ulyatt ◽  
A. R. Egan
Keyword(s):  
Organic Matter ◽  
Small Intestine ◽  
Organic Acids ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Crude Protein ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Water Soluble Carbohydrate ◽  
Dietary Origin

SUMMARYThe extents and sites of digestion of organic matter (OM), and its constituent watersoluble carbohydrates, organic acids, pectin, cellulose, hemicellulose and crude protein have been studied in sheep prepared with re-entrant duodenal cannulas and fed four fresh herbage diets, Ruanui perennial ryegrass, Tama Westerwolds ryegrass, Pitau white clover and Fakir sainfoin, at each of two levels of intake.The water-soluble carbohydrate, organic acids and pectin of all diets were almost completely digested within the rumen. Some 10% of water soluble carbohydrate reached the duodenum on each diet, though this may not have been of dietary origin. Only on legume diets, where pectin concentration was higher, did measurable amounts of pectin reach the intestine, accounting for some 5% of the pectin.Hemicellulose and cellulose digestibilities differed between diets, being lowest for sainfoin, and next lowest for clover. Between 79 and 94% of digestible hemicellulose was digested in the stomach, but diet and intake had no significant effect on this partition. Of the digestible cellulose, 87–97% was digested in the stomach.Digestibility of N was lowest for sainfoin and highest for Tama ryegrass. There were no significant differences between herbage species or intake in the percentage of digested N digested in the stomach or intestines. The tannin contained in sainfoin had no effect on nitrogen digestion.Data from this and other studies reported in the literature were examined as a basis for establishing prediction equations whereby the partition of digestion of the major carbohydrate and nitrogenous constituents in stomach and intestines might be estimated from data obtainable from standard digestibility trials. Regressions were developed for predicting the amounts of OM, cellulose, and hemicellulose digested in the stomach. There are not yet enough suitable data available to predict the amount of nitrogen entering the small intestine.

The effects of a wide range of nitrogen application rates on the yields from a perennial ryegrass sward with and without white clover

1970 ◽  
Vol 74 (2) ◽  
pp. 227-240 ◽  
Author(s):  
D. Reid
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Nitrogen Fertilizer ◽  
Crude Protein ◽  
Dry Matter ◽  
Growth Curves ◽  
Nitrogen Rate ◽  
Wide Range ◽  
Grass Sward ◽  
Nitrogen Rates

SUMMARYA series of twenty-one nitrogen fertilizer rates ranging from 0 to 800 lb nitrogen/acre (897 kg/ha)/annum was applied on a pure S. 23 perennial ryegrass sward and on an S. 23 ryegrass sward containing S. 100 white clover. Total yields of herbage dry matter and crude protein from both swards at all the nitrogen rates were determined each year by cutting the herbage five times at approximately the same stage of growth on each occasion. Four-parameter growth curves relating herbage yield to nitrogen rate were fitted to the data, and are presented for the first 3 years of the experiment. On the pure-grass sward the response of dry-matter yield to nitrogen rate was almost linear between the 0 and 300 lb nitrogen/acre (336 kg/ha) rates, then it decreased steadily, becoming non-significant about the 500 lb/acre (560 kg/ha) rate. In contrast the response of crude-protein yield was virtually linear from the 0 to the 600–700 lb nitrogen/acre (673–785 kg/ha) rates. The inclusion of white clover in the sward increased the yields of dry matter and crude protein at the low nitrogen rates, but decreased the responses, with the result that the yields and responses of the grass + clover sward were not significantly different from those of the pure-grass sward at nitrogen rates above about 300 lb/ acre (336 kg/ha). In terms of profitability at present fertilizer prices the optimum nitrogen rate for dry-matter production on both swards was estimated to be 400–450 lb/ acre (448–504 kg/ha), whereas that for crude-protein production was greater than 600 lb/acre (673 kg/ha). The value of clover in a sward receiving nitrogen fertilizer is discussed.

White clover: the forgotten component of high-producing pastures?

2017 ◽  
Vol 57 (7) ◽  
pp. 1269 ◽  
Author(s):  
D. F. Chapman ◽  
J. M. Lee ◽  
L. Rossi ◽  
G. R. Edwards ◽  
J. B. Pinxterhuis ◽  
...  
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Production Systems ◽  
Nutrient Loss ◽  
Dairy Production ◽  
Lolium Perenne L ◽  
Agronomic Practices ◽  
Trifolium Repens L ◽  
N Rates

The contribution of white clover (Trifolium repens L.) to nitrogen fixation and feed quality in mixed pastures is indisputable, but the benefits of clover inclusion to total herbage accumulation (HA) are less clear. Results from four experiments comparing mixed pastures of white clover–perennial ryegrass (Lolium perenne L.) with perennial ryegrass monocultures are presented. These experiments covered a range of environments (dryland northern New Zealand and irrigated southern New Zealand), management inputs (nitrogen (N) fertiliser rates and defoliation management), and genotypes of ryegrass and white clover. Mixtures resulted in a significantly greater HA than did monocultures in 7 of the 8 years for which data were available; the interaction between pasture type (monoculture or mixture) and N rate was significant in six of those years, with a greater advantage in HA for mixtures under low N rates (mean = 3.08 t DM/ha.year) than under high N rates (mean = 1.54 t DM/ha.year). Two-thirds to four-fifths of the yield advantage under grazing was due to the direct effect of clover contribution (which ranged between 10% and 30% of total annual yield) to HA, most of which accrued in summer. The remainder was due to the capture of additional clover-derived N by the grass component of the mixture, estimated to equate to 50–60 kg N/ha under low N-fertiliser rates and 15–35 kg N/ha under high N rates. The magnitude and consistency of the yield advantages observed here indicates that there are unrealised yield and other benefits not currently being captured in New Zealand dairy production systems, largely because they are negated by the use of high N-fertiliser rates. The agronomic practices required to support clover-rich mixed pastures receiving moderate rates of N fertiliser are well documented and can be applied to help deal with nutrient loss limits required by environmental regulations plus volatility in farm-gate milk prices.

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