Corn Silage
Hybrids…...picking the winners so you won’t be a loser Mike
Rankin The corn silage hybrid selection game is one of trade-offs. This includes trade-offs between yield and feed quality and sometimes it means trade-offs between one quality trait over another. Further, there always seems to be one more quality trait to throw into the mix. Examples of the types trade-offs a grower might have to make are choosing a highly digestible brown mid-rib hybrid at the expense of yield or choosing a highly digestible, leafy gene hybrid at the expense of starch content. Don’t sweat the small stuff As you move through the selection process, it’s important to keep things in perspective and try not to get hung-up on small differences. This is especially true with forage quality traits like NDF digestibility and starch. A point or two one way or the other is not a big deal when comparing hybrids. On the other hand, don’t ignore large differences. Although there are many more quality traits to analyze today versus ten years ago, keep in mind that yield and other agronomic traits must remain at the top of your selection criteria (spoken like a true agronomist!!). The key to selection on the agronomic side of the fence is consistency…..across years and locations. Generally speaking, look for those hybrids that are routinely in the top 10 percent for milk per acre, a performance criteria that combines both yield and quality terms. Of course there may be times and circumstances when you are looking to maximize a specific trait. Examples might be when your are growing silage specifically for heifers and yield is your primary selection criteria or if you’re after maximum milk production and digestibility or energy is of greatest importance. A look at the 2003 UW Corn Silage Hybrid Performance data…… A person can learn a lot by curling up in front of the fireplace on a cold winter night, foregoing the most recent episode of “My Big Fat Obnoxious Fiancé”, and taking a close look at silage hybrid performance data. In the case of the UW trials, the data is widely available in print form and on the internet. Let’s begin by focusing on the South Central Region trial, which includes the Fond du Lac County site (Table 1).
The important point to be gleaned from Table 1 is that there is a large amount of genetic diversity for all of the traits listed. It is this diversity that growers must exploit! Diversity in performance also exists within hybrid trait groups (e.g. Bt hybrids, Roundup Ready hybrids, leafy hybrids, etc.). Thus, if you narrow your selection criteria down to a few traits, the job still isn’t done. You must exploit performance diversity within that group. Here are some general statements that I think currently apply to some of these special trait hybrids: Bt and Roundup Ready · Holding their own…..these traits do not seem to compromise other yield or quality characteristics. Leafy · A mixed bag…..performance is all over the chart. These are generally average to well below average in starch content. Brown Mid-rib · In a class by themselves for digestibility · Yield is still a concern. New hybrids are said to be better but that will need to be proven. “Highly Digestible” hybrids · Generally above average for digestibility, but…… · Just putting a “HD” in the hybrid name doesn’t necessarily mean it’s superior in digestibility than some other hybrids without the “HD” designation. · These should get better with time. High Oil Corn · No apparent feeding advantage for silage. Too much dilution effect. Some final thoughts…. There is no one “best” corn silage hybrid but there clearly are differences in performance among agronomic and forage quality traits. Do your homework now to exploit these differences!!! It’s generally never a good idea to make a selection based on one trait. Likewise, don’t make selections based solely on performance data from a single location. Think of LOCATIONS as ENVIRONMENTS and obtain data from as many sources as possible (e.g. UW, seed company, on farm tests, etc.). Look for consistency in performance and use agronomic traits to narrow the field of possible selections. Corn silage quality starts with hybrid selection. However, it can end quickly if a good management isn’t applied at the harvest and storage end of the operation. In other words, the extra money spent on an elite hybrid goes into the manure pit if you don’t harvest at the proper moisture, insure good packing, and exclude air during the storage period.
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