The Sexy One

The author is a dairy nutrition consultant with GPS Dairy Consulting LLC and is based in Malone, Wis.

It's the new “sexy” forage, also known as the cocktail mix; it’s mysterious, unknown, and risky. She is a femme fatale. Seductive, she draws her lover into a compromised relationship. Once she is planted, there are many promises — but no guarantees.

Dramatic? Perhaps, but before you start dating this forage, be ready for a rocky relationship with highs and lows.

The cocktail mix moniker is, of course, unspecific. In the field, we think of a cocktail as a mix of warm- and cool-season annual grasses and legumes. With such a generic, although alluring, name, it’s not surprising that cereal forages, clovers, sorghums, ryegrasses, and other species all come into play. By planting a mix, it is hoped to take advantage of various growing conditions. In some cases, yields in excess of 4 tons of dry matter per acre have proven to outperform alfalfa.

Have eyes wide open

Following are some considerations that will help you better understand this new relationship and ensure that cocktail mixes meet your expectations.

Forage quality and yield: I have seen the Twitter post documenting a relative forage quality (RFQ) of 240 for a cocktail mix. There are four questions that must be asked regarding such a claim:

1. What was the cost per ton of dry matter? Lost in the discussion at times with various alternative forages is the actual cost. If five to six cuttings are harvested, the tractor and equipment are driven across the field five to six times. How does this influence the actual cost per ton of dry matter averaged across the year?
2. What was the yield? Regardless of whether you have an annual grass, alfalfa, or corn silage, there is always the balance of quality versus yield; you need a certain number of tons for forage (and fiber) to feed cows for an entire year.
3. Do you want to feed rocket fuel? Forage that is extremely high in quality can work in some diets, but it likely cannot be the sole forage; cows have a need for undigestible forage (undigestible neutral detergent fiber [uNDF]) to maintain proper rumen function.
4. Is this repeatable? One Twitter post from a random farmer doesn’t tell you if this will work on your farm with your soil conditions in both a wet or dry year.

Seasonal flux: Most farms might have some fields planted to a cocktail mix while maintaining alfalfa in others — call it risk management or a lack of commitment to the relationship. This leads to a fundamental flaw in the system; namely, there becomes a lack of synchronicity between your alfalfa forage cuttings and the cocktail cuttings. How do you manage four cuttings of alfalfa and multiple cuttings of the cocktail mix? One strategy is to store the cocktail mix separately. On large dairies, bunker and pile space is at a premium; multiple cuts are then stored in front of other cuts, leading to more frequent changes in forage quality.

Storing cocktail forages separately in bales or bags can be an option, but this invariably leads to inconsistent feed coming out of storage. I think there are two reasonable options to help solve this issue. First, if possible, time the cuttings to coincide with your alfalfa and layer the forages in the bunker or pile, even though yield might be compromised slightly to sync cuttings.

Layering isn’t pretty, but it can be effective. Packing and more packing is critical. If a quality facer is used, and the forage is pushed and “mixed” adequately with a bucket, a forage mix can be fed that is consistent day to day and will change slowly over a longer period of time. Cows (and nutritionists) thrive on consistency. If the same bunker of feed can be fed for four months, there is time to make small adjustments based on cow response. If forages are switched every four to six weeks, then there is a need to constantly “chase” the cow response.

Second, if the feed is stored in bags or small piles, use this forage at a low feeding rate (less 5% of dry matter) to limit the effect of variability on the cow.

Allocation of forages: With cocktail mixes, there will certainly be times when the quality does not meet high-producing cow standards. Far-off dry cows and bred heifers can be a great place to allocate these forages. However, for farms without heifers, it is easy to become heavy on a forage that has a limited need.

Consistency: Most nutritionists are not in love with the sexy cocktail mix but rather prefer her bland looking sister — corn silage. While we argue with each other over brown midrib and conventional hybrids, we mostly enjoy the stability in the corn silage relationship because we generally know what to expect. Yields and quality vary with corn silage, too, but there is usually just one change a year. For the highest producing herds, consistency is often the common theme. Will a cocktail mix work in your system to maintain this consistency?

Harvest targets: Harvest targets for corn silage and alfalfa are well established. Alfalfa scissors clippings and fall dry-down reporting for corn silage have become standard practices in many areas. But what is the target for cocktail mix blends?

For alfalfa, we often target 33% to 36% NDFom. For some grass blends, this is far too low. A high-quality grass with high fiber digestibility might have an NDFom of 42% to 44%. One option is using a combination of aNDFom and uNDF240 (undigestible fiber) with a target of 48% to 52%. For example, alfalfa at 34% NDFom and 16% uNDF240 has a combined value of 50; grass forage at 44% NDFom and 7% uNDF240 would have a combined value of 51. Using the 48% to 52% combination parameter might be helpful in evaluating timing of harvest across multiple, variable fields. I’ve seen combined forage bunker silos with 40% NDFom and 10% uNDF240 that fed well.

Starting a relatively new relationship with a sexy forage can work, but keep your eyes wide open to the potential for variable yields and forage quality.