Timing of alfalfa harvest should be determined by the goals of each operation, and largely focus on one of two desired endpoints: supreme quality for dairy cattle, or improved quantity for animals with lower nutrient requirements.
When aiming for the former goal, and harvesting for supreme or improved quality, animal requirements are generally the first consideration. In many cases, dairies will harvest on a fairly rigorous schedule in order to produce supreme quality forage to meet the large nutrient demands of dairy cattle. Figure 1 gives an indication of the differing nutrient needs based on animal production status, and how that can correspond to forage quality when using relative forage quality (RFQ).
With conventional and Roundup Ready alfalfa varieties, it is important to harvest on a shorter harvest interval to be able to capture that improved digestibility and lower fiber content, as well as higher overall crude protein to meet the demands of lactating and growing cattle. In this instance, it makes sense to have a goal for higher quality forage so that animal production remains high.
The second goal of harvesting for maximum yield often comes with a tradeoff in forage quality, as forages including alfalfa will decline in digestibility and other nutrients while increasing in fiber and lignin as they mature (Figure 2). However, in that exchange the plant will accumulate more biomass until the plant reaches about 50% flower.
Bud stage generally is dairy quality hay (with about 50% leaves), with alfalfa yield being about 80% of full potential but the enhanced milk production more that makes up for the yield loss. Those producing hay for the beef or even horse markets may wait until 25-50% bloom to capture increased yield as they do not need as high of quality to meet animal demands.
Thus, the recommendations for cutting first cutting alfalfa are:
For Growing Animals:
- Cut at bud stage or 27 inches height, whichever comes first; if grass with the alfalfa may have to harvest when the grass begins to head out.
- Cut at early flower or 32 inches height, whichever comes first.
- Don’t wait to harvest too late, as increased risk of lodging may occur with heavy rains if left in the field for too long.
For later cuttings of alfalfa, base it again on animal needs’, but you may have a slightly longer window to work with.
For Growing Animals, Beef, and Horse markets:
- We often see producers harvest on a 25-28 day harvest schedule, depending on the area.
- You can extend your harvest interval slightly, between 30-32 days, depending on location and animal needs.
- Recognize the longer you wait to harvest, the lower your forage quality will be, and there are limits to alfalfa yield gains beyond 50% bloom.
- Take care if utilizing any traited technology, as the signed Technology Stewardship Agreement (TSA) states that in alfalfa seed production areas traited alfalfa must be harvested at or before 10% bloom and that in all other areas it must be harvested prior to 50% bloom
Continue to monitor your forage with forage quality analyses, to determine if your forage is meeting your animals’ production needs.
If utilizing HarvXtra alfalfa, we have increased flexibility in our harvest interval because our forage quality will not decline at the same rate. Harvest first cutting HarvXtra with the same criteria, the forage will be slightly higher forage quality but if left longer on first cutting the alfalfa will lodge as any conventional variety would. For subsequent cuttings, you can optimize your forage quality even further if choosing to remain on the same harvest schedule that you would have with your conventional alfalfa. This can lead to improvements in animal performance if alfalfa is fed at significant amounts in the ration. If choosing to optimize yield, you can again delay harvest, in many cases by 7-10 days, and still have high quality forage comparable to conventional harvested 7-10 days prior. However, this technology will provide you the yield advantage, without the quality sacrifice. The other advantage of HarvXtra technology is that quality will be higher if harvest is delayed by rain, which is often an inevitable occurrence for many farmers.
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