HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Baron, V. S. Articles by King, J. R. Search for Related Content PubMed Articles by Baron, V. S. Articles by King, J. R. Agricola Articles by Baron, V. S. Articles by King, J. R. Related Collections Forage Management Other Forage Crops

FORAGES

Leaf and Stem Mass Characteristics of Cool-Season Grasses Grown in the Canadian Parkland

^a Agriculture and Agri-Food Canada, 6000 C & E Trail, Lacombe, AB, T4L 1W1 Canada
^b Agriculture, Food and Nutritional Science, Agriculture/Forestry Centre, Univ. of Alberta, Edmonton, AB, T6C 2P5 Canada

baronv{at}em.agr.ca

	ABSTRACT

TOP ABSTRACT INTRODUCTION Materials and methods Results and discussion Summary REFERENCES

 
Grasses adapted to both hay and pasture are lacking in the prairie parkland. `Regar' meadow bromegrass (Bromus riparius Rhem.), `Manchar' smooth bromegrass (B. inermis Leyss.), S9044 (a smooth–meadow bromegrass cross), common meadow foxtail (Alopercurus pratensis L.), and `Kay' orchardgrass (Dactylis glomerata L.) were evaluated for traits useful in dual purpose grass species at early (late May), late (late June), and regrowth (early September) harvests. Herbage, leaf, and stem nutritive value; mass; and leaf/stem ratio were determined. Differences among species were related more to herbage mass and morphology than to leaf and stem quality. Early harvest orchardgrass herbage mass was low at 55% of meadow foxtail (2.9 Mg ha^-1). However, stem content of meadow foxtail represented 60% of early herbage mass, limiting its potential. Regrowth mass of meadow bromegrass, S9044, and orchardgrass exceeded 2.5 Mg ha^-1, whereas smooth bromegrass and meadow foxtail were as low as 2.1 Mg ha^-1. Regrowth leaf mass of the former species exceeded 1.9 Mg ha^-1. Late herbage mass of smooth bromegrass was always greater than the other species. Leaf acid detergent fiber (ADF) of S9044 and smooth bromegrass was lower (range 189–242 g kg^-1) than meadow bromegrass (range 217–284 g kg^-1). By contrast, late and regrowth harvest stem ADF of meadow bromegrass was lower (range 237–360 g kg^-1) than S9044 (range 257–366 g kg^-1). Variation among Bromus types for late and regrowth yield, and leaf fiber may influence management strategies.

Abbreviations: ADF, acid detergent fiber • NDF, neutral detergent fiber • IVDOM, in vitro digestible organic matter • LSR, leaf/stem ratio

	INTRODUCTION

TOP ABSTRACT INTRODUCTION Materials and methods Results and discussion Summary REFERENCES

 
MATCHING forage nutritive value and availability with livestock production goals is a challenge, especially in areas with short growing seasons. In central Alberta, Canada, grass species with regrowth characteristics necessary in intensive pasture management were not available until the last decade. Species and genotypes within species with adequate regrowth characteristics have been identified and developed during the last 10 to 15 yr. Examples are meadow foxtail, meadow bromegrass, and crosses between meadow and smooth bromegrass.

Meadow foxtail and meadow bromegrass are particularly well adapted for grazing, but are sometimes used for hay in the western parkland of Alberta (Baron and Knowles, 1984; Knowles and Baron, 1990; Knowles et al., 1993). Meadow bromegrass–smooth bromegrass crosses have been made to develop dual-purpose grazing/hay type cultivars for the Canadian Prairies (Knowles and Armstrong, 1984). During the late 1980s and through the 1990s, orchardgrass has been grown extensively in the more moist areas of Alberta. These genotypes have been compared for seasonal herbage mass when cut frequently and infrequently (Knowles and Baron, 1990; Knowles et al., 1993), but comprehensive evaluation of their potential is required to provide improved seasonal utilization.

When characterizing forage potential of grass species used for hay and grazing, it is important to evaluate traits such as mass, sward structure, plant morphology, and nutritive value of leaf and stem materials. Defining forage quality potential for hay (often initial growth) is relatively simple compared with pasture, since hay can be fed ad libitum in stalls to estimate intake, and digestible dry matter intake is directly related to forage quality. Some selection of leaf material occurs, but most of the entire plant is consumed.

Under grazing, the relationships between forage mass, sward structure, and nutritive value are important aspects of forage potential. Forage mass and sward structure (leaf/stem ratio, leaf mass, etc.) may influence animal intake (Coleman, 1992) and must be taken into consideration together with conventional nutritive parameters. As pasture mass increases animal intake levels off, and forage nutritive value becomes more important than sward structure. The pasture mass at maximum intake is often obscure, varying from 1.2 Mg ha^-1 of green leaf material in cool-season grasses to 3.5 Mg ha^-1 in warm-season grasses (Coleman, 1992; Forbes and Coleman, 1993; Penning et al., 1994). Also, ruminant animals tend to select leaves instead of stems (Poppi et al., 1980) and select live material instead of dead material (Hodgson, 1982). The degree to which this occurs depends on mass available per animal, forage maturity, and length of rest period.

During initial growth, leaves and stems of cool-season grasses vary in relative forage quality and quantity, and decrease in nutritive value with maturity (Nelson and Moser, 1994). Both leaf blades and stems decrease in nutritive value as plants mature, but stems decrease faster than leaves. As stem elongation proceeds, the percentage of whole-plant material accounted for by stems increases (Kilcher and Troelsen, 1973; Nelson and Moser, 1994). In a short growing season, changes in nutritive value and morphology occur quickly and management systems have to be established to make the most of them. During regrowth, much less variation in whole-plant forage nutritive value occurs because plants are largely composed of leaf blades (Van Soest, 1982; Nelson and Moser, 1994).

Variation for forage nutritive value has been shown among varieties within species. The variability is primarily due to morphological differences (Buxton, 1990) among genotypes, but may include variation among chemical constituents and relationships among constituents that limit digestibility. These relationships also vary among genotypes as they mature (Casler, 1986; Buxton, 1990).

Previous research has examined nutritive value of leaves and stems of smooth bromegrass and orchardgrass (Kilcher and Troelsen, 1973; Buxton and Marten, 1989; Buxton, 1990). However, similar information is not available for meadow bromegrass, meadow foxtail (Alopecurus pratensis L.), or crosses between meadow and smooth bromegrass. The objective of this research was to characterize meadow bromegrass, S9044 (an interspecific hybrid population from a meadow–smooth bromegrass cross), and meadow foxtail for leaf blade, and stem mass (sheath plus stem and inflorescence), herbage mass, and nutritive value during initial spring growth and late-summer or fall regrowth compared with smooth bromegrass and orchardgrass.

	Materials and methods

TOP ABSTRACT INTRODUCTION Materials and methods Results and discussion Summary REFERENCES

 
Regar meadow bromegrass, Manchar smooth bromegrass [an interspecific hybrid population (S9044) from a meadow–smooth bromegrass cross (Knowles and Armstrong, 1984)], common meadow foxtail, and Kay orchardgrass were observed for herbage yield, leaf and stem mass, and nutritive value at three harvests. These were early and late initial growth (including tillers having undergone floral initiation) and a late-season regrowth. From this point on the harvests will be referred to as early, late, and regrowth. The studies were carried out during 1987 and 1989. Plots were established at Lacombe, AB, on an Orthic Black Chernozemic Ponoka clay loam (Udic Boroll) soil in 1986 and 1988. The harvests were randomized within each of four replicates. The species were randomized within each harvest block and seeded in eight rows 6 m long with a spacing of 0.3 m in 1986–1987 and 0.25 m in 1988–1989. Plots were seeded in June the year before use. Seeding rate for all species was 100 pure live seeds m^-1 of row. Phosphorus and potash fertilizers were broadcast before greenup in the spring (early April) at rates of 48 kg ha^-1 P and 150 kg ha^-1 K in 1987 and 43 kg ha^-1 P and 79 kg ha^-1 K in 1989. Four equal applications of 50 kg ha^-1 N each were made starting late the previous fall (October, early May, late June, and late July). Additional N from P and K sources brought the total applications to 228 kg ha^-1 N.

Plot areas were prepared for harvest by clipping with a flail mower to a height of 5 cm the fall before starting the experiment. Plots used for early growth were cut 26 May 1987 and 30 May 1989. Those used for late growth were cut 23 and 27 June in the respective years. Regrowth plots were clipped to a height of 5 cm 23 and 26 July in the respective years. They were harvested again on 9 Sept. 1987 and 19 Sept. 1989. All harvests were unique to each plot in each year. New plot areas were seeded the year before cutting so that plots harvested were unique for each harvest year. The three harvest times chosen for the present study were based on period of growth, stage of development, and potential for utilization as hay or grazing. Times of early and regrowth harvests were chosen when herbage mass and growth stage were appropriate for grazing (primarily vegetative with average yields >2 Mg ha^-1). Late growth should be comparable to first cut hay, providing contrasts in morphology to growth at early and regrowth harvests. It was not intended to provide a regrowth harvest subsequent to the late harvest to simulate a hay system. That type of study with the same or similar genotypes has been conducted previously (Baron and Knowles, 1984; Knowles and Baron, 1990; Knowles et al., 1993). Regrowth harvest did not come from these plots.

At each harvest a subsample was removed from the innermost two rows of each species subplot with a total area of 0.0465 m² cut at a height of 5 cm. Tillers from this subsample were divided into leaf blades and stem plus sheath (stem) fractions immediately after removal from the plot. The leaf and stem fractions were dried separately at 55°C and weighed. Leaf, stem, and herbage mass and leaf/stem ratio (LSR) were calculated from the dry weights. A separate area of the plot (border row) sufficient to provide a fresh sample of about 1 kg was cut at a height of 5 cm. The sample was frozen immediately and stored at approximately -18°C. After thawing, the samples were separated into leaf and stem fractions and dried at 55°C for 72 h. A portion of the frozen material was retained for analyses of herbage (whole-plant) forage quality. Each dried fraction was ground, using a Wiley mill (Model 4; Arthur H. Thomas Co., Philadelphia, PA) equipped with a 1-mm screen and then a 0.5-mm screen using a Cyclone mill (Model MS; UDY Corp., Boulder, CO) before forage quality determinations. The leaf, stem, and herbage samples were analyzed for total N concentration using a micro-Kjeldahl technique (Wall and Gerke, 1975) and an autoanalyzer system (Technicon Industrial Systems Corp., Tarrytown, NY, industrial method 786-86T, 1987) and multiplied by 6.25 and expressed as crude protein. In vitro digestible organic matter concentration (IVDOM) was measured via direct acidification during a 24-h second stage pepsin digestion (Marten and Barnes, 1980). Neutral detergent fiber (NDF) and ADF concentrations were determined sequentially (Van Soest and Robertson, 1980).

Statistical Methods
The layout of the experiment was a factorial design in a split-plot arrangement of treatments. Within years, the main plots were harvests and the subplots were species. Years and harvests were tested for homogeneity of variance using the Chi-square test as described by Gomez and Gomez (1984). The year effect was heterogeneous for nearly all variables, so years were analyzed separately. The GLM procedure (SAS Inst., 1989) for analyses of variance was used to determine the significance of harvest, species, and parts effects and their interactions. Two statistical analyses were used. When herbage, leaf and stem mass, leaf/stem ratio, and herbage nutritional value were analyzed, the model (stated previously) was a split plot with harvest the main plots and species the subplots. All variables measured were based on a single sample from each species subplot. When leaf and stem (parts) were included (for leaf and stem forage quality), the analyses was arranged as a strip-split-block (Gomez and Gomez, 1984) because there were leaf and stem subsamples (sub-subplots) from each species subplot. All effects except replicates were assumed fixed. Mean differences were tested using an LSD only after the appropriate F-test was shown to be significant at (P 0.05). References to significant differences adhere to this probability level.

	Results and discussion

TOP ABSTRACT INTRODUCTION Materials and methods Results and discussion Summary REFERENCES

 
Climatic Observations
The climate of the parkland of Alberta is classified as continental prairie with a subhumid moisture regime (Phillips, 1990). Lacombe, where the research was conducted, has an 89-yr average frost-free period (above -2°C) of 122 d. Long-term average mean monthly temperatures are 10°C for May, 14°C for June, 16°C for July, 15°C for August, and 10°C for September. Mean precipitation for the same period is 51 mm for May, 81 mm for June, 78 mm for July, 64 mm for August, and 42 mm for September. Climatic data were determined within 1.5 km of the test site. Mean temperatures were average to above average during the test period. Precipitation was near average during both years for the period affecting early growth, but was substantially below average during June of both years and therefore could have limited late yield. Regrowth (late July and August) received average to above average rainfall, although September was drier with 61% of the long-term average in both years.

Harvest, Within and Averaged across Species
Mass and Morphology
Harvest date frequently interacted significantly with forage species and plant part. Herbage mass, morphology, and nutritive value patterns changed with season and with plant development. Late-harvest herbage mass was expected to be greater than early or regrowth mass. However, species varied for herbage production between early and regrowth harvests. This indicated species differences for early and late season dry matter distribution (Table 1) and therefore for potential use at these times. Herbage mass between early and regrowth harvests was similar for meadow bromegrass and meadow foxtail, within species, but S-9044 and orchardgrass had superior regrowth compared with early harvest yield.

Leaf/stem ratio reflected the variation of leaf and stem mass with harvest and year (Tables 1 and 2) and is a trait that can affect preference during grazing (Coleman 1992). Regrowth stem production was greater in 1989 than in 1987 (Table 2), resulting in lower LSR. In 1987, all species except S9044 had higher regrowth LSR than early harvest, whereas in 1989, only meadow bromegrass had a higher LSR at regrowth. Meadow foxtail had similar LSR at both early and late harvests.

Herbage Nutritive Value
Harvest effects on herbage nutritive value within species are reported in Tables 3 and 4 . The general relationship between early and regrowth harvests was in agreement with Van Soest (1982), who indicated that early season pasture has a higher nutritive value than pasture grown and available during late summer and fall. However, there was an occasional break from the general pattern. For example, crude protein concentration of meadow foxtail was similar for early and regrowth harvests in 1989. In 1987, both crude protein and ADF concentrations for smooth bromegrass were similar for early and regrowth harvests.

Species Variation: Within and Averaged across Harvest
Herbage, Leaf, and Stem Masses and LSR
There was variability among species for herbage, leaf, and stem mass within harvest dates. Meadow foxtail had high early harvest herbage mass (although not significantly different from smooth and meadow bromegrass) indicating potential for early grazing (Table 1), but stems contributed >60% of the total (Table 2). Meadow foxtail had the highest early harvest stem mass, greater than meadow bromegrass (which had comparable leaf mass) by 2 times in 1987 and 1.7 times in 1989. The high-proportion of stem material in meadow foxtail could hinder grazing (Hodgson et al., 1994; Penning et al., 1994). Therefore, meadow foxtail should be grazed earlier (third week of May), even though herbage mass may be less than ideal. Early harvest bromegrasses had similar herbage and leaf mass and LSR. However, herbage mass of S9044 was 69% of meadow foxtail in 1987 and 75% of it in 1989. Orchardgrass consistently had the lowest early harvest herbage mass (Table 1). Early harvest herbage masses of orchardgrass were 61 and 47% of meadow foxtail and 76 and 51% of meadow bromegrass in 1987 and 1989, respectively. Herbage mass of orchardgrass was highly dependent on leaf production (Table 2) as indicated by a consistently high LSR across harvests (Table 1).

Regrowth S9044 consistently ranked first for herbage mass, although orchardgrass was similar to the bromegrasses in early September. Van Esbroeck et al. (1995) observed that meadow bromegrass and S9044 regrew more rapidly than smooth bromegrass. Regrowth herbage mass for S9044 and smooth bromegrass depended more than meadow bromegrass on stem production. Stem mass of meadow bromegrass was 44% of S9044 in 1987 and 54% of S9044 in 1989. Smooth bromegrass stem mass was 2.2 times greater than meadow bromegrass when they had similar regrowth herbage mass in 1989. Regrowth stems of S9044 (1987 and 1989) and smooth bromegrass (1989) consisted of elongated material, whereas those of meadow bromegrass consisted of leaf sheath material similar to orchardgrass. From a structural and morphological perspective, herbage mass of S9044 and smooth bromegrass would not be as desirable for grazing as meadow bromegrass at equal herbage masses. Leaf blade percentage and density of leaf blade material from sward surface to ground positively influences animal preference and intake (Hodgson, 1982).

Smooth bromegrass had highest late harvest herbage mass (Table 1) in both years and highest stem mass in 1987 (Table 2). Late harvest leaf masses of smooth and meadow bromegrass were similar, but meadow bromegrass had a higher leaf mass than S9044 in both years. Late harvest LSR for all bromegrasses were similar in late June in both years. Late harvest herbage mass for orchardgrass was less than smooth bromegrass and S9044 in both years. The 4-yr average from a four-cut clipping trial that compared the dry-matter production of meadow bromegrass to the other species and varieties, smooth bromegrass yielded 80% as much dry matter; smooth meadow bromegrass hybrids, 85% as much; meadow foxtail, 86% as much; and orchardgrass, 82% as much dry matter (Knowles et al., 1993).

In two-cut hay tests, S9044 produced as much dry matter as smooth bromegrass cultivars, but meadow bromegrass did not (Knowles and Baron, 1990). The comparable performance of S9044 to smooth bromegrass when cut infrequently was due to an above-average late first cut mass and superior regrowth mass, when given a long rest period.

Herbage Nutritive Value
Among factors affecting whole-plant nutritive value, herbage ADF was the only variable with consistent trends among species within harvests in both years (Table 4). The bromegrasses had greater ADF than orchardgrass and meadow foxtail at late harvest. Meadow bromegrass was higher in ADF than orchardgrass for all harvest-years except regrowth in 1989. Smooth bromegrass had lower regrowth ADF than meadow bromegrass.

Plant Part Nutritive Value
Although the harvest x species x plant part interaction was almost always significant in both years, differences among species within harvests and parts were not generally consistent or very large. However, the species x plant part interaction was always significant for nutritive value traits and was more useful in finding leaf and stem differences for species within harvests.

Leaf IVDOM had few consistent trends among species within harvest, but averaged across harvests S9044 was higher than all except meadow bromegrass in 1987, and highest overall in 1989 (Table 5). Within harvests, regrowth stem IVDOM of meadow bromegrass was greater than S9044 and meadow foxtail. Averaged across harvests, stem IVDOM of orchardgrass and meadow bromegrass was greater than S9044 and meadow foxtail. Early harvest leaves and stems had similar IVDOM values within species. Similarity of leaf and stem fractions for IVDOM during early growth has been documented previously (Mowat et al., 1965; Hacker and Minson, 1981).

Smooth bromegrass had a higher regrowth leaf crude protein concentration than meadow bromegrass, meadow foxtail, and orchardgrass (Table 6); S9044 was intermediate for leaf protein concentration. There was no consistent trend and few significant differences among species within harvest for stem-crude protein. Orchardgrass ranked lowest for crude protein. Smooth bromegrass had lower regrowth ADF than meadow bromegrass values averaged across harvests in both years and in two of three harvests in 1989.

Of all nutritive value components, fiber concentrations showed the greatest divergence among species within harvests and plant parts, especially among the bromegrasses. In general, there was little variation for leaf NDF among species within harvest, but meadow bromegrass had higher leaf NDF concentrations than S9044 (Table 7), averaged over harvests. At regrowth and averaged over harvests, orchardgrass had lower stem NDF than S9044. Meadow bromegrass had lower regrowth stem NDF than S9044.

Averaged across harvests, meadow bromegrass had the highest leaf ADF of all species. Smooth bromegrass had leaf ADF values of 79%, and S9044 had leaf ADF values of 82% of meadow bromegrass in 1987; comparable figures for 1989 were 89 and 84%, respectively. Meadow bromegrass had higher leaf ADF concentrations than smooth bromegrass for late and regrowth harvests, and had higher late harvest leaf ADF than meadow foxtail (Table 8). Orchardgrass generally had leaf ADF concentrations similar to or higher than smooth bromegrass, S9044 and meadow foxtail.

Given the higher leaf IVDOM and lower leaf NDF and ADF of S9044 compared with meadow bromegrass, it appears the selection of the smooth bromegrass leaf-type may have been advantageous for S9044. Meadow bromegrass leaves appear narrow and thicker than S9044 or smooth bromegrass. Meadow bromegrass has a higher specific leaf weight than smooth bromegrass and S9044 (Van Esbroeck et al., 1995). This may be an indication of higher leaf density and more structural-to-nonstructural material. While no anatomical comparisons have been made to our knowledge, meadow bromegrass appeared to have more venation on a cross-sectional basis than the other bromegrass types. However, Buxton and Marten (1989) found no difference in IVDOM due to specific leaf weight in reed canarygrass (Phalaris arundinacea L.) lines selected bi-directionally for the trait. While Buxton (1990) observed differences for NDF values among the same lines, he concluded that morphological features of the lines were not necessarily related to forage quality.

Generally, stems of meadow bromegrass were similar in nutritive value to those of orchardgrass, but greater than S9044, particularly during 1989 and averaged over harvests in both years (Tables 5–8). This was the opposite relationship among species for leaves. Averaged across harvests, stem ADF of S9044 was highest or among the highest, meadow bromegrass was intermediate, and orchardgrass was lowest or among the lowest. Stem ADF of meadow bromegrass was 95% of S9044 in 1987 and 96% in 1989.

Averaged across harvests, leaf and stem ADF of meadow bromegrass were similar, but stem was greater than leaf ADF for other species (Table 8). Early and regrowth harvest leaf and stem ADF were similar for meadow bromegrass and orchardgrass in both years. Stem ADF of S9044 was greater than leaf ADF at late and regrowth harvests and averaged over harvests in both years. Therefore, some of the positive attributes of superior leaf nutritive value, observed in S9044 (associated with smooth bromegrass), were offset to a certain extent by poorer stem nutritive value.

Meadow bromegrass was predominantly vegetative during early growth and regrowth, and at late harvest vegetative tillers had been reinitiated. As mentioned previously, some elongated tillers were evident on both smooth bromegrass and S9044 during regrowth. Thus, the regrowth stem material of meadow bromegrass consisted entirely of leaf sheath material, whereas in the other two bromegrass types some true stem material existed. Leaf sheaths are usually intermediate for IVDOM between leaf blade and true stem material (Hacker and Minson, 1981).

	Summary

TOP ABSTRACT INTRODUCTION Materials and methods Results and discussion Summary REFERENCES

 
The research evaluated species on the basis of traits associated with grazing and conserved feed uses, but did not evaluate either use per se. Thus results may be addressed only in terms of potential. The three harvest times provide opportunities to evaluate the species where divergence in the traits might have relevance to management. Among the species only smooth bromegrass is used widely and is considered to have wide adaptability on the prairie parkland.

Differences among cool-season grass species for traits that affect management for hay or grazing were clearer for mass than for herbage or plant-part nutritive value. In a short-season area, high productivity both early and late in the growing season is important to maximize the number of available grazing days. At equivalent herbage mass, species with higher nutritive value may provide grazers with a considerable economic advantage. However, if producers in a short-season area must choose between higher quality or higher herbage mass at regrowth, they will probably opt for higher mass.

The bromegrasses provided variability for early, late, and regrowth herbage production and for leaf and stem ADF concentration. Meadow bromegrass and S9044 appeared to have the greatest potential among species other than smooth bromegrass. Meadow bromegrass had attributes for grazing in a short-season area. Early harvest and regrowth herbage production was relatively abundant, and leaf production and LSR was as high or higher than other species during regrowth. The low stem component during regrowth resulted in a dense leafy sward, which could positively influence grazing. However, late harvest herbage mass of meadow bromegrass was lower than smooth bromegrass, and leaf material of meadow bromegrass frequently had higher fiber concentration than the other bromegrasses. The relatively high leaf ADF levels for meadow bromegrass must be offset by its capacity to produce leaf mass during early and regrowth harvests.

Hybrids of smooth and meadow bromegrass, such as S9044, may have great potential for use as dual purpose hay and pasture types. Hybrid S9044 had abundant herbage production of relatively high nutritive value. Regrowth herbage mass was as high or higher than meadow bromegrass and leaf material was generally as high or higher in nutritive value than other species. Leaf material of S9044 was of particularly high nutritive value, having a lower ADF than meadow bromegrass. This was offset by a tendency to produce more true stem regrowth of lower nutritive value than meadow bromegrass. As a general-purpose bromegrass type, S9044-type cultivars may be desirable because of greater and more consistent regrowth mass at regrowth than smooth bromegrass. Smooth bromegrass, as expected, exhibited superior late harvest yield typical of adaptation to hay production.

While the positive attributes of orchardgrass are well documented, the relatively low early harvest herbage production make it less useful than meadow bromegrass for grazing, and less useful than smooth bromegrass for hay in the Prairie Parklands. Nutritive value of meadow foxtail was generally similar to other species, but either lack of leaf production during early and late harvests or too much stem production during early and regrowth harvests make it less desirable than the bromegrass types for either hay or pasture. The most positive attribute of meadow foxtail was high and early herbage mass. However, this was offset by early stem production, which could prove detrimental to grazing. During the period from early to late harvest, meadow foxtail appeared to have little leaf production or accumulation and the continuous production of floral tillers shown in this and other studies makes it more difficult to manage.SAS Institute 1989

	ACKNOWLEDGMENTS

 
We are grateful for the financial assistance received from Farming for the Future, which is part of the Alberta Heritage Trust Fund. The authors acknowledge the technical support of David Young, Brenda Lowles, Debbie Archer, and Pam Randall and the critical review of the manuscript by Dr. S.W. Coleman, Dr. P.L. Dubeski, Dr. D.H. McCartney, and Dr. B. Coulman.

Received for publication February 8, 1999.

	REFERENCES

TOP ABSTRACT INTRODUCTION Materials and methods Results and discussion Summary REFERENCES

 

• Baron V.S., Knowles R.P. Use and improvement of meadow bromegrass as a pasture species for Western Canada. In: Siemer E.G., Delaney R.H., eds. Proc. of 2nd Intermountain Meadow Symp., Gunnison, CO. Fort Collins: Colorado State Univ, 1984:37-45 11–13 July 1984. Spec. Ser. 34..
• Buxton D.R. Cell wall components in divergent germplasms of four perennial forage grass species. Crop Sci. 1990;30:402-408.[Abstract/Free Full Text]
• Buxton D.R., Marten G.C. Forage quality of plant parts of perennial grasses and relationship to phenology. Crop Sci. 1989;29:429-435.[Abstract/Free Full Text]
• Casler M.D. Causal effects among forage yield and quality measures of smooth bromegrass. Can. J. Plant Sci. 1986;66:591-600.
• Coleman S.W. Plant–animal interface. J. Prod. Agric. 1992;5:7-13.
• Fairbourn M.L. First harvest phenological stage effects on production of eight irrigated grasses. Agron. J. 1983;75:189-192.[Abstract/Free Full Text]
• Forbes T.D.A., Coleman S.W. Forage intake and ingestive behavior of cattle grazing old world bluestems. Agron. J. 1993;85:808-816.[Abstract/Free Full Text]
• Gomez K.A., Gomez A.A. Statistical procedures for agricultural research, 2nd ed Toronto, ON: John Wiley & Sons, 1984.
• Hacker J.B., Minson D.J. The digestibility of plant parts. Herb. Abstr. 1981;51:459-482.
• Hodgson J. Influence of sward characteristics on diet selection and herbage intake by the grazing animal. In: Hacker J.B., ed. Nutritional limits to animal production from pasture. Farnham Royale, UK: Commonwealth Agric. Bureau, 1982:153-166.
• Hodgson J., Clark D.A., Mitchell R.J. Foraging behavior in grazing animals and its impact on plant communities. In: Fahey G.C., Jr., et al. , ed. Forage quality, evaluation, and utilization. Madison, WI: ASA, CSSA, and SSSA, 1994:796-827.
• Jewiss O.R. Morphological and physiological aspects of growth of grasses during the vegetative phase. In: Milthorpe J.L., Ivins J.D., eds. Growth of cereals and grasses. London: Butterworths, 1966:39-56.
• Kilcher M.R., Troelsen J.E. Contribution of stems and leaves to the composition and nutrient content of irrigated bromegrass at different stages of development. Can. J. Plant Sci. 1973;53:767-771.
• Knowles, R.P., and K.C. Armstrong. 1984. Breeding improvement of meadow bromegrass, Bromus riparius Rhem. p. 75. In Agronomy abstracts. ASA, Madison, WI.
• Knowles R.P., Baron V.S. Performance of hybrids of smooth bromegrass (Bromus inermiss Leyss) and meadow bromegrass (B. riparius Rhem). Can. J. Plant Sci. 1990;70:330.
• Knowles R.P., Baron V.S., McCartney D.H. Meadow bromegrass. Ottawa, ON: Agriculture Canada Publ. 1889/E. Communications Branch, 1993.
• Marten G.C., Barnes R.F. Prediction of energy digestibility of forages and fungal enzyme systems. In: Pigden W.J., et al. , ed. Standardization of analytical methodology for feeds. Ottawa, ON: IDRC-134e, 1980:61-71.
• Mowat D.N., Fulkerson R.S., Tossel W.E., Winch J.E. The in vitro digestibility and protein content of leaf and stem portions of forages. Can. J. Plant Sci. 1965;45:321-331.
• Nelson C.J., Moser L.E. Plant factors affecting forage quality. In: Fahey G.C., Jr., ed. Forage quality, evaluation, and utilization. Madison, WI: ASA, CSSA, and SSSA, 1994:115-154.
• Penning P.D., Parsons A.J., Oit R.J., Hooper G.E. Intake and behavior responses by sheep to changes in sward characteristics under rotational grazing. Grass Forage Sci. 1994;49:476-486.
• Phillips, D.W. 1990. The climates of Canada. Environment Canada Public. Catalogue EN56-1/1990E. Minister of Supply and Services, Government of Canada, Ottawa, ON.
• Poppi D.P., Minson D.J., Ternouth J.H. Studies of cattle and sheep eating leaf and stem fractions of grasses: I. The voluntary intake, digestibility and retention time in the reticulo-rumen. Aust. J. Agric. Res. 1980;32:99-108.
• SAS Institute. SAS users guide: Statisics. Version 6.0. Cary, NC: SAS Inst, 1989.
• Smith D., Bula R.J., Walgenbach R.P. Forage management, 5th ed Dubuque, IA: Kendall/Hunt, 1986.
• Van Esbroeck G.A., Baron V.S. Effect of mefluidide application date on yield and forage quality of Bromus species. Can. J. Plant Sci. 1990;70:717-726.
• Van Esbroeck G.A., Baron V.S., King J.R. Regrowth of bromegrass species, a bromegrass interspecific hybrid and meadow foxtail in a short-season environment. Agron. J. 1995;87:244-251.[Abstract/Free Full Text]
• Van Soest P.J. Nutritional ecology of the ruminant. Corvallis, OR: O & B Books, 1982.
• Van Soest P.J., Robertson J.B. Systems analyses for evaluation of fibrous feeds. In: Pigden W.J., et al. , ed. Standardization of analytical methodology for feeds. Ottawa, ON: IDRC-134e, 1980:49-60.
• Wall L.L., Gerke G.W. An automated total protein nitrogen method. J. Assoc. Off. Anal. Chem. 1975;58:1221-1226.

This article has been cited by other articles:

				J. F. Karn, J. D. Berdahl, and A. B. Frank Nutritive Quality of Four Perennial Grasses as Affected by Species, Cultivar, Maturity, and Plant Tissue Agron. J., October 3, 2006; 98(6): 1400 - 1409. [Abstract] [Full Text] [PDF]

				V. S. Baron, A. C. Dick, M. Bjorge, and G. Lastiwka Stockpiling Potential of Perennial Forage Species Adapted to the Canadian Western Prairie Parkland Agron. J., November 1, 2004; 96(6): 1545 - 1552. [Abstract] [Full Text] [PDF]

				Y. S.N. Ferdinandez and B. E. Coulman Nutritive Values of Smooth Bromegrass, Meadow Bromegrass, and Meadow Smooth Bromegrass Hybrids for Different Plant Parts and Growth Stages Crop Sci., March 1, 2001; 41(2): 473 - 478. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Baron, V. S. Articles by King, J. R. Search for Related Content PubMed Articles by Baron, V. S. Articles by King, J. R. Agricola Articles by Baron, V. S. Articles by King, J. R. Related Collections Forage Management Other Forage Crops