By Andi Anderson
May and June are critical months for dairy producers in Michigan, with a growing list of fieldwork tasks such as planting and manure spreading. Among these, the first cutting of alfalfa emerges as a priority, especially given its substantial impact on the season's total yield and forage quality.
The first alfalfa harvest, traditionally the highest yielding, sets the tone for the season. If not conducted timely, quality degradation due to increased fiber content NDF and reduced digestibility can affect cows' nutritional intake. This first cut influences forage quality and schedules subsequent harvests throughout the season.
To determine the optimal harvest time, dairy farmers can utilize several methods:
Growing Degree Days (GDD):
- GDD is a measure of heat accumulation used to predict plant development rates.
- For alfalfa, a target range of 680-750 GDD is recommended to estimate when the plant has received sufficient heat to reach maturity for the first cut.
- Monitoring GDD helps determine the best time to begin scouting the fields for readiness.
Plant Height:
- Plant height is a straightforward and practical indicator of alfalfa maturity.
- Optimal harvesting is recommended when the tallest plants in the field reach approximately 28 inches, typically indicating they are at the bud stage.
- This height suggests the plants are mature enough to harvest while maintaining good forage quality.
Predictive Equations for Alfalfa Quality (PEAQ):
- PEAQ is a method used to estimate potential feed quality based on current plant height and growth stage.
- A PEAQ stick, which is a special measuring tool, can be used directly in the field to measure and estimate Relative Feed Value (RFV) and Neutral Detergent Fiber (NDF) levels.
- While PEAQ provides a good initial assessment, it’s recommended to confirm these values through laboratory testing to ensure accurate feed ration formulation.
Michigan State University's forage specialists, including Kim Cassida, emphasize the importance of harvesting alfalfa before corn planting. Delaying alfalfa cutting to complete corn planting can drastically reduce forage quality, making it unsuitable for lactating cows and only fit for dry cows or heifers.
The warm spring this year may cause early corn planting, prompting dairy farmers to prioritize alfalfa harvesting over corn planting. Delays in corn planting have minimal impact on fall harvest quality, while each day's delay can significantly degrade the forage quality crucial for dairy production.
The first alfalfa cut is a decisive factor for dairy farm productivity, emphasizing the need for strategic planning and timely action to ensure the health and productivity of dairy herds.
Photo Credit: gettyimages-gabrielabertolini
Categories: Michigan, Crops, Alfalfa