Stockpiled Pasture 4
Performance of Four Grass Species in Stockpiling Systems
Table of Contents
- Forage Quality
- Summary and Interpretation
Stockpiling is the practice of allowing certain hay or pasture
fields to regrow during mid-summer or early fall so they are available
for grazing later in the season. Stockpile grazing is also known
as deferred grazing or fall-saved pasture. The primary reason for
using stockpiled pasture is to save on feed costs. In this report,
we discussed the yield and quality of several grass species under
two stockpile management systems.
This study was conducted in small research plots under clipping
management. The trial was established in 1993 and harvested from
1994 to 1996. The grass species involved were: reed canarygrass,
smooth bromegrass, tall fescue, meadow bromegrass, orchardgrass,
and Matua prairiegrass. The Matua prairiegrass did not survive the
first winter and will not be discussed further. The orchardgrass
provided data in 1994 but suffered winter damage and was not suitable
for harvested in the final two years of the study.
The grass species were evaluated under two management systems:
the Hay system consisted of a single harvest in early July followed
by stockpiling until the fall harvests were taken. The Pasture system
consisted of a harvest in mid-June, another harvest in late July,
followed by stockpiling until the fall harvests were taken. Thus,
the Hay system had only 1 cut (early July) prior to stockpiling,
while the Pasture system had two cuts (mid-June and late July) prior
To assess yield and quality in the fall, sufficient plots were
available to harvest one complete set in early September, early
October, and early November. All yield and quality data presented
below represents the average of these three fall harvest dates.
The effect of harvest date on stockpile yield and quality is discussed
in a separate report.
Stockpile Yield in the Fall
The fall yield of grass species varied with management system.
Under the Hay system, reed canarygrass was consistently the highest
producer in the fall (Figure 1). Absolute yields
were quite high, averaging over 5 tonnes/ha of dry matter. There
was little difference in fall yield of the other three grass species
under the Hay system. Under the Pasture system, tall fescue and
meadow bromegrass tended to be the highest yielding species, while
smooth bromegrass was consistently the lowest.
Pasture grass yield under stockpiling.
Total Seasonal Yield
A successful stockpiling system should also provide acceptable
forage yields during the spring and summer time periods. Overall,
grasses under the Hay management produced more total forage per
year than those under the Pasture management system. This is not
unusual since under hay management the grasses are allowed to reach
the period of maximum dry matter accumulation. Under the Hay management
system, reed canarygrass produced the most forage when both the
first cut (hay) and fall cut (stockpiled forage) are considered
(Figure 2). Reed canarygrass was lower yielding
in 1994 because it was a somewhat thin stand in the first year,
which is normal for this grass species. Under the Pasture management
system, meadow bromegrass tended to produce the most forage over
the June and July harvests plus the fall harvest. Differences among
the other grasses were relatively small.
Total seasonal yield of grasses under two management systems.
The crude protein content of stockpiled grasses was consistently
higher under the Pasture system as compared to the Hay system (Figure
3). Under the Hay system, reed canarygrass tended to have lower
protein values as compared to the other grass species, while under
the Pasture system reed canarygrass generally had high protein values.
Other differences in crude protein content among grass species were
quite small. Note that under the Pasture system in 1995, smooth
brome did not have enough forage available for quality analysis
due to drought, therefore it is not included for that year or in
Crude protein content of stockpiled grasses.
Total Digestible Nutrients (TDN)
Overall, the total digestible nutrient (TDN) content of the stockpiled
forage was higher under the Pasture system as compared to the Hay
system (Figure 4). Tall fescue consistently had
the highest TDN content under both management systems. This finding
is significant for those wanting to establish forages with stockpiling
in mind. Tall fescue has long been recognized in the central USA
as an excellent grass for stockpiling and our data seems to support
this. Meadow bromegrass consistently had the lowest TDN values under
stockpiling. Meadow brome tends to form only leaves in the regrowth
and it mats easily, causing the lower leaves to die. This accumulation
of brown leaves is likely resulting in lower energy values. It seems
likely that meadow bromegrass should be managed by using shorter
regrowth intervals if it is to be stockpiled.
TDN content of stockpiled grasses.
Yield of TDN
The yield of total digestible nutrients can be calculated by multiplying
the %TDN by the dry matter yield. The result gives an indication
of which grasses provide the most "energy per acre" under
stockpiling. This is a useful value where animals are at medium
or low levels of nutrient requirements, such as dry cows or ewes.
Overall, the TDN yield was significantly higher under the Hay management
system (Figure 5). This results from the much
higher yields achieved under the Hay system, despite somewhat higher
TDN values under the Pasture system. Under the Hay management system,
reed canarygrass tended to have the highest TDN yields, followed
by tall fescue. Under the Pasture management system, tall fescue
and meadow bromegrass had the highest TDN yields. Thus, the ideal
pasture grass for stockpiling will vary depending on the management
system used to accumulate the stockpile.
TDN yield of stockpiled grasses.
Summary and Interpretation
The results of this study show that stockpile management systems
that allow long regrowth periods prior to fall grazing (ie: the
Hay management system above) produce much higher stockpile yields
than those that allow shorter regrowth periods (ie: our Pasture
management system). At the same time, systems that allow shorter
regrowth periods provide higher crude protein and energy in the
forage for fall grazing.
Under the Hay management system, reed canarygrass was generally
the highest yielding species both in the fall and over the entire
season. When its excellent yield potential is considered along with
excellent winterhardiness and drought tolerance, we would suggest
that reed canarygrass should be much more widely used in Ontario,
both for summer and late fall grazing (note that this would only
apply to low-alkaloid varieties proven adapted in Ontario). Under
the pasture management system, tall fescue and meadow bromegrass
had the highest fall yields, while meadow bromegrass had the highest
yields over the entire season. Both of these species have excellent
potential for use in Ontario where a grass with rapid regrowth is
required. Tall fescue is reputed to have palatability problems,
but this seems to vary over the season and can be overcome with
a combination of haying and grazing. We would have expected orchardgrass
to also perform well in our Pasture system had it not been damaged
after the first winter.
Tall fescue consistently had the highest TDN values in both the
Hay and Pasture systems. This information supports data from the
USA and indicates that tall fescue should be considered in new seedings
where late-fall grazing is one of the primary objectives.
When selecting grass species for full-season use as well as fall
grazing, the type of animals to be grazed should be considered.
Where fall grazing is primarily for livestock with low nutrient
requirements (ie: dry cows or ewes), grasses with high seasonal
and fall yields should be used (ie: reed canarygrass, meadow bromegrass).
Where fall grazing is primarily for livestock with medium to high
nutrient requirements (ie: breeding ewes, weaned lambs or calves,
stockers), species with a combination of high yields and high absolute
quality need to be considered (ie: tall fescue). The usefulness
of legumes in fall grazing programs is currently under investigation