Suitable grass species and varieties can offer significant advantages when included in alfalfa-grass mixtures for dairy cows and milking goats as haylage, baleage or dry hay. These advantages include nutritional improvements in fibre digestibility, increased intake and higher milk production, as well as agronomic and harvest advantages.
There is currently a great deal of interest by dairy producers to include newer grasses in alfalfa-grass mixtures, and a move away from the use of alfalfa-timothy. Improved Quality Seeds varieties of highly digestible meadow fescue (Tetrax, Pardus), soft-leaf tall fescue (Cowgirl, Otaria / Elodie), late-maturing orchardgrass (Dividend VL, Diceros), festulolium (Lofa), and perennial ryegrass (Tetragain) offer significant benefits.
1. Agronomic Advantages
Alfalfa-grass mixtures typically yield higher than straight alfalfa stands. In Ontario trials, yield increases of 15 - 20% are typically observed. Nitrogen fixed by the alfalfa is used by the grasses to meet their high nitrogen requirements. Grasses have much less issues with persistence and are more tolerant to variable drainage, low potassium fertility, disease and winterkill. Grasses in mixed stands provide some protection against lodging and also are better able to compete with weeds.
2. Harvest & Storage Advantages
Grasses in mixed alfalfa stands enable faster wilting and drying, resulting in reduced respiration losses of non-fibre carbohydrates. Because alfalfa tends to buffer itself during haylage fermentation with a slower drop in pH, grasses can also improve fermentation, particularly in baleage situations.
3. Dairy Cow Nutrition Advantages
Grasses tend to lose forage quality faster than alfalfa after the heading stage, so it is critical that cutting schedules be timely. Unlike in the past when first-cut was started in mid-June and it was followed by one or two cuts, most dairy producers today begin in late-May and aim to cut every 4 weeks. Grass mixtures can work very well with current cutting schedules. Early-cut grasses are very palatable and can complement alfalfa nutritionally.
Grasses are higher in fibre (NDF) than alfalfa, but are also much higher in fibre digestibility (NDFD). Refer to Table 1 – Fibre (NDF) & Fibre Digestibility (NDFD) Levels of Alfalfa & Grass. Although there is a wide range, grasses may have 12 – 13 % points higher NDF than alfalfa, but grasses also have at least 12 – 13% points higher NDFD or more. Grasses contain much more hemicellulose than alfalfa, which is the highly digestible component of forage fibre.
Higher fibre digestibility has two benefits – higher digestible energy per unit of feed as well as higher cow intake, resulting in more milk per cow. This is especially the case where intake is limiting production – transition, fresh and high producing cows. A much quoted study by Oba & Allen, MI State 1999 concluded that for every 1 percentage point increase in NDFD, intake increases 0.37 lbs/day and milk increases 0.55 lbs milk/day. Dr Jerry Cherney, Cornell University, has stated “Feeding trials across the USA have shown that a one percentage unit increase in NDFD increases milk production by 0.5 to 1.0 lbs/cow/day, and more than 1.0 lb/cow/day for the highest producing cows”. Grasses in early cut alfalfa-grass mixtures can complement the alfalfa by improving fibre digestibility. Even small percentages of grass in an alfalfa-grass mix can provide significant improvements in NDFD. Alfalfa-grass mixtures with 25% grass can significantly improve NDFD by over 3 percentage points over straight alfalfa.
Table 1 – Fibre (NDF) & Fibre Digestibility (NDFD) Levels of Alfalfa & Grass
(Source – Dairy Forage Lab, Ithica, NY and Miner Institute)
When nitrogen is not limiting, grasses have moderately high crude protein levels, but not as high as alfalfa. Alfalfa often has very high crude protein (CP) levels, but the CP is very soluble, limiting its efficient utilization by the cow. Mixed alfalfa-grass stands can have high CP content with better utilization.
Rumen Dynamics
Alfalfa and grasses can complement each other in a dairy ration. As discussed previously, grasses have higher fibre (NDF) levels (~12% points) than alfalfa, but they also have greater fibre digestibility (NDFD) (~12% points, 30 hours). Grasses also have much lower levels of undigestible fibre (uNDFD240) that limit intake. While alfalfa fibre has an initial faster rate of digestion, it then slows down. Grasses have a greater extent of digestion. This results in higher animal intake.
The fibre particles in grasses are less fragile in the rumen than in alfalfa with more longer particles, so the particle size decreases less rapidly. This improves the physically effective fibre (peNDF) in the rumen. This decreases the need to add straw to a TMR to provide minimum physically effective fibre for proper rumen function and cow health, while contributing much more digestible energy than straw.
How Much Grass Is Optimum?
Variability of grass percentage in alfalfa mixtures is a potential issue because it can result in variable quality forage. Keep in mind that % grass in a seed mixture is not the same as % grass in the subsequent forage stand. Some grass species are more aggressive than others, and small seed amounts (as low as 3%) can result in significantly more growth. Percent grass also changes over time and is strongly influenced by environmental conditions such as rainfall during and after establishment, and cool spring temperatures.
Early Cornell University research suggests that the optimum grass in alfalfa-grass mixtures at the end of the seeding year may be around 5 – 15% grass, with about 20 – 30% in the first full production year. Cornell University and some laboratories have developed NIRS calibration equations to estimate grass percentages in alfalfa-grass samples. (Alfalfa- Grass Mixture – 2016 Update http://blogs.cornell.edu/whatscroppingup/2016/12/02/alfalfa-grass-mixtures-2016-update/)
To prevent against excessive grass percentage in alfalfa-grass stands, too much grass when it occurs can be managed by:
1. selecting an aggressive alfalfa variety,
2. selecting the appropriate grass species and varieties,
3. using the correct grass seeding rate,
4. avoiding excessive liquid manure (nitrogen) application, and
5. lowering the cutting height from 3-4 inches to about 2 inches for a cut or two.
Timothy
Historically, timothy has been the main grass species used in alfalfa-grass mixtures. However, there has been a move away from timothy as many dairy producers have looked for species that are more productive agronomically as well as providing higher feed quality in the ration. “Old school” advantages of timothy include:
late heading dates are more suitable to late first-cutting (June),
it is less competitive with alfalfa,
the seed is small and mixes well with alfalfa to go through the drill small seed box, and
the seed is relatively inexpensive.
The weakness of timothy is that it is shallow-rooted with very poor drought tolerance. It is also daylight sensitive which makes it want to grow in the spring but not after late-June with decreasing day-lengths. This results in lots of timothy growth in the first-cut, but very little regrowth, making it a “first-cut wonder” with poor seasonal growth distribution. Alfalfa-timothy mixtures are inconsistent across cuttings, having a high percentage of timothy in the first-cut while subsequent cuts are almost straight alfalfa. Other improved grass species have higher seasonal yield. Also, timothy is not very tolerant to frequent, aggressive dairy haylage cutting schedules.
Improved Grass Species & Varieties
Quality Seeds is introducing the “M.D.” Maximum Digestibility designation on our most digestible grass varieties. Grass varieties that are marked M.D. are significantly higher in fibre digestibility (NDFD) than other varieties of the same species. These grasses offer maximum fibre digestibility and increased intakes to help promote higher milk production and beef gains.
1. “Tetrax” and “Pardus” Meadow Fescues
Meadow fescue has recently been rediscovered as an excellent grass to include in dairy haylage alfalfa-grass mixtures. Quality Seeds plot data and research by Cornell University and Miner Institute shows much opportunity with alfalfa-meadow fescue mixtures. Meadow fescue has higher fibre digestibility and forage quality than most other grass species. Meadow fescue is less competitive with alfalfa, which can be an advantage in alfalfa-grass mixtures where a modest grass content is more desirable. It has a soft texture and is high in palatability.
Meadow fescues have excellent winterhardiness. Drying rate is much faster than ryegrass or festuloliums. Small amounts of meadow fescue seed can be included in alfalfa mixtures and still flow through a drill small seed box.
“Pardus” meadow fescue is a relatively new leafy, high yielding variety exclusive to Quality Seeds. Pardus is noted for its very soft leaves and extremely high fibre digestibility. It has strong disease resistance and is very persistent.
“Tetrax” is a next generation meadow fescue that is being introduced for 2020. It is the first tetraploid meadow fescue introduced to the market and is also exclusive to Quality Seeds. It is an extremely soft leaved variety with superior digestibility and palatability. It is also very persistent. Tetrax is a M.D. Maximum Digestibility designated variety.
2. “Cowgirl”, “Otaria” & “Elodie” Tall Fescues
These newly developed soft leaf tall fescues are much improved in palatability and quality than the older tall fescue varieties, which tended to be coarser, less palatable, with lower forage quality. Soft-leaf tall fescues are much softer in texture, and provide a big improvement in palatability and intake. They are very high in fibre digestibility. Soft-leaf tall fescues have excellent agronomics and are high yielding compared to other forage grass species. Tall fescues are deep rooted and very drought tolerant, and can provide significant vegetative growth during hot, dry summer weather.
Soft-leaf tall fescues wilt and dry quickly so it is suitable for haylage, baleage or dry hay. Of course, Cowgirl, Otaria & Elodie are endophyte-free varieties. Experience has shown that modest amounts of tall fescue seed can be included in alfalfa mixtures and still flow through a drill small seed box and provide significant growth.
Cowgirl tall fescue is a relatively new soft-leaf variety that was bred for improved forage quality. Elodie and Otaria are the new generation of extremely soft-leaf tall fescues. They have superior palatability and digestibility compared to older varieties, along with outstanding drought tolerance and persistence, with excellent regrowth. Elodie and Otaria are both M.D. Maximum Digestibility designated varieties.
3. “Dividend VL” Orchardgrass
Dividend VL is an exclusive Quality Seeds orchardgrass variety that works exceptionally well in alfalfa-grass mixtures. Older orchardgrass varieties have a reputation of early maturity (early May) and poor forage quality, but this has dramatically changed with the introduction of this newer very late maturing variety. Dividend VL was bred at the University of Guelph. In Ontario Forage Crops Committee trials at Elora, Dividend VL orchardgrass had much later heading dates than other orchardgrass varieties (more than 3 weeks later than early varieties) and a similar heading date to late-maturing timothy varieties. Research also shows that Dividend VL is slower than other orchardgrass varieties to decline in digestibility and palatability after heading, providing a much a wider harvest window. Dividend VL is a M.D. Maximum Digestibility designated variety.
Dividend VL has become a staple in many of Quality Seeds alfalfa-grass mixtures with high yields, excellent forage quality and high fibre digestibility. Dividend VL is leafy, fine textured and very palatable. It also provides high yields of vegetative regrowth in subsequent cuts. It wilts and dries quickly so it is suitable for haylage, baleage or dry hay. Dividend VL seed is coated so that when mixed with alfalfa and other grass seed at 3 to 5%, it will flow through a drill small seed box.
4. “Lofa” Festulolium
Festuloliums are crosses between ryegrass and either meadow or tall fescue. They have been selected to have the forage quality and fast growth of the ryegrass combined with the persistence of the fescue.
Quality Seeds Lofa festulolium has inherited high forage quality from its Italian ryegrass parent, but with improved yield, growth during hot dry summer weather, and persistence from its tall fescue parent. It is noted for being very high in sugar content and digestible energy. A strong root system allows it to be more productive in dry summer weather than ryegrass. It is best suited to aggressive cutting schedules in dairy haylage systems.
Although it will head out every 28 days or earlier, feed analysis data shows that Lofa maintains its nutrient quality advantage after heading very well. It can be competitive with alfalfa in mixtures so percentage inclusion should be modest. Festuloliums can sometimes be difficult to dry for hay, so they work better when harvested as haylage or baleage.
5. “TetraGain” Perennial Ryegrass
TetraGain is a new tetraploid perennial ryegrass that is extremely productive in cool and damp climates. It is high yielding under these conditions with good cold tolerance and disease resistance. TetraGain has exceptionally high nutritional feed value, with very high sugar content, fibre digestibility, digestible energy and palatability. TetraGain has much improved persistence compared to other perennial ryegrass varieties. Perennial ryegrass can be more difficult to dry, so haylage or baleage is a more suitable harvest option than dry hay.
Suggested QS Alfalfa-Grass Seed Mixtures
Quality Seeds alfalfa-grass mixtures that are currently being offered to dairy producers to make high quality haylage include:
90% Quality Seeds alfalfa
5% Cowgirl tall fescue
5% Pardus or Tetrax meadow fescue
85% Quality Seeds alfalfa
10% Tetrax meadow fescue
5% Cowgirl tall fescue
5% Quality Seeds alfalfa
15% Tetrax meadow fescue
90% Quality Seeds alfalfa
7% Cowgirl tall fescue
3% Dividend VL orchardgrass
94% Quality Seeds alfalfa
3% Lofa festulolium
3% Dividend VL orchardgrass
These mixtures provide high forage quality as well as increased yields. They have the additional benefit that the seed mixtures will flow through the small seed box on most drills. Talk to your Quality Seeds representative to choose the alfalfa variety and grass mixture best suited to your farm and management.
Grass Mixtures With Highly Digestible “Boost HG” Alfalfa
The newest alfalfa variety at Quality Seeds is “Boost HG”, a non-transgenic, non-Roundup Ready, highly digestible alfalfa that was developed by conventional plant breeding using Hi-Gest® Technology. It has much improved fibre digestibility and forage quality, increasing digestible energy and animal intake for higher milk production. Trial data typically also shows crude protein levels about 1 percentage point higher. It provides greater harvest flexibility for higher quality forage.
To complement its higher fibre digestibility and increase it even higher, Boost HG is being marketed in alfalfa-grass mixtures with high performance, high fibre digestibility grass varieties – Tetrax or Pardus meadow fescue, Cowgirl tall fescue, Dividend VL orchardgrass, and Lofa festulolium.
Pure Grass Stands
These grass species and varieties can also have excellent performance when grown in pure grass stand mixtures when managed appropriately. Quality Seeds offers the grass mixture “Milk Max”, suitable for dairy haylage and baleage, consisting of 25% Dividend VL orchardgrass, 25% Cowgirl tall fescue, 25% Pardus meadow fescue and 25% TetraGain perennial ryegrass.
The newly introduced “HayMax” mix which can be dried for dry hay, consists of 45% Pardus meadow fescue, 40% Otaria / Elodie tall fescue and 15% Diceros orchardgrass. Fertilizing each grass cut with nitrogen is important for yield and quality. Regrowth is faster and more vigorous when cutting height is 4 inches.
Quality Seeds Grass Variety Research
Quality Seeds has positioned itself to be the Canadian leader in improved grass species and varieties. Searching around the world for new potential “game changer” grass and alfalfa varieties, they are tested in Canadian environments to research how they perform for yield, quality and persistence in our soils and climates. Quality Seeds has been a leader in innovation by introducing new specialty trait grasses, such as highly digestible Tetrax and Pardus meadow fescues, soft-leaf Cowgirl, Otaria and Elidie tall fescue, late-maturing Dividend and Diceros orchardgrass, , and high yielding and sugar content Lofa festulolium, as well as the extremely highly digestible Evolution Italian ryegrass. New Quality Seeds varieties of the next generation of highly digestible grasses are being introduced in 2020.
Figures 1 & 2 - Screening for high forage nutrient quality and improved agronomics at the grass variety and alfalfa-grass mixture plots, Quality Seeds, Vaughan, Ontario.