– Dr. Chris Teutsch, Forage Extension, UK Grain and Forage Center of Excellence at Princeton
Figure 1. Impact of stage of maturity at harvest on forage quality (Blaser et al., 1986).
Last fall we analyzed 1,127 hay samples as part of the Eastern, Central, and South-Central Kentucky Hay Contests. A summary of the results can be found in Table 1. Nutrient requirement s of various livestock classes can be found in Table 2. So here is what we found:
• Crude protein (4.6 to 26.7%) and total digestible nutrients (39 to 76%) varied widely
• 3% of the hay samples contained less than 50% TDN
• 1.4% of the hay samples contained less than 8% crude protein
• 283 samples or 25% contained enough energy to meet the requirements of a beef cow at peak lactation
• 777 samples or 69% would meet the protein requirements of a beef cow at peak lactation
• 1111 samples or 99% contained enough protein to meet the needs of a dry pregnant cow
• 1091 samples or 97% contained enough energy to meet the requirements of a dry pregnant cow
In general, a higher percentage of hay samples required supplementation to meet the energy needs of a lactating beef cow (75% in 2024 versus 40% in 2023). This was most likely due to rain delays in harvest, allowing forages to become more mature and therefore lower in forage quality (Figure 1). I guess the biggest take home from the 2024 samples is that we still have a way to go in terms of improving hay quality!
So, what don’t these results tell us? Since there is still wide variation in both crude protein and energy for the hay samples in this dataset, the average or median of the results CANNOT be used to make recommendations on what or how much to supplement. To make this type of recommendation, you will need to sample individual hay lots (one cutting from one field) that you will be feeding (see AGR-257 Hay Sampling Strategies for Getting a Good Sample). Once you have the results in hand, then a supplementation strategy can be designed by either working your local extension agent, nutritionist or veterinarian or by using the UK Beef Cow Forage Supplementation Tool.
Hay Quality was Lower in 2024
A good New Years’s Resolution for 2025 would be to improve hay quality! Making just a few small tweaks to your hay production program can make a big difference in hay quality. Below is a short list of things that you can implement to improve hay quality and production on your farm.
• Fertilize and lime according to soil test. A balanced fertility program is essential for optimizing hay yield and quality. Phosphorus, potassium, and lime should be applied according to soil test results. Avoid using “complete” fertilizers such as 10-10-10. These fertilizers commonly over apply phosphorus and under apply potash.
• Apply nitrogen early to promote rapid spring growth. Applying 80 lb N/A in mid- to late March will promote early growth in hay meadows, resulting in higher first harvest yields with improved crude protein values. Recent research at the University of Kentucky has shown that fall nitrogen fertilization promotes hay growth in the spring. In fact, 80 lb N/A applied in the fall was equivalent to more than 100 lb N/A applied in the spring.
• Harvest at the boot stage. The single most important factor impacting forage quality is stage of maturity at harvest. Hayfields should be mowed as soon as the grass reaches the late boot-stage. The boot stage occurs when the sheath of the flag leaf swells just prior to the emergence of the seed head. By making the first cutting in a timely manner, we will have time to make a leafy second cutting just prior to the summer months.
• Mow early in day. Some studies have shown that sugars tend to highest in late afternoon, making this the optimal time of day to cut. However, in high rainfall environment like Kentucky, maximizing curing time is the highest priority. Therefore, hay should be mowed in mid to late morning after the dew has dried off.
• Use mower-conditioner. Conditioning the stems allows moisture to escape at a faster rate. This shortens curing time and improves your chances of avoiding rain. Conditioning is especially important for first cutting grasses, summer annual grasses, and legumes, all of which tend to have larger stems.
• Set swath on mower-conditioner to the widest possible setting. Maximizing the swath width decreases curing or wilting time by exposing a larger portion of the forage to direct sunlight.
• Rake or ted at 40-50% moisture content. Raking and tedding the forage while it is still pliable helps to reduce leaf loss and maintain forage quality. Once the moisture content is below 40%, leaf loss increases, especially in l
• Legumes such as alfalfa and clover.
• Bale at 18-20% moisture. Baling in this moisture range inhibits mold growth and reduces heating. Avoid baling hay that is excessively dry due to high levels of leaf loss and hay that is above 20% moisture due to heating and potential hay fires.
• Store dry hay under cover and off the ground. Protecting hay from weathering helps to reduce dry matter losses and maintain forage quality. Much of the weathering damage is a result of the hay bale wicking moisture up from the ground. So, storing hay off the ground can greatly reduce deterioration.
• Consider using baleage. The biggest advantage of baleage is the shortened period between mowing and baling. In many cases, hay can be mowed one day and baled the next. This facilitates harvesting hay at the correct stage of growth, the NUMBER ONE factor impacting forage quality. To learn more about baleage see AGR-235 Baleage: Frequently Asked Questions.
If you need help with hay sampling or interpreting your hay testing results, make sure and contact your local extension agent.
Forage testing is available from several commercial labs and the Kentucky Department of Agriculture. The Kentucky Department of Agriculture offers a standard forage analysis to Kentucky producers for a reduced cost.
Table 1. Summary of 2024 Hay Contest forage quality results. Samples (n=1127) were collected by extension agents, dried in a forced air oven, ground to pass through a 1 mm screen, and predicted using a near infrared spectroscopy.
More information on this program can be found at http://www.kyagr.com/marketing/forage-program.html. Make sure and use a lab that has been certified for accuracy and precision by the National Forage Testing Association. A list of certified labs can be found at NFTA Certified Labs.
Table 2. Nutritional requirements of various livestock classes. Adapted from Southern Forages, Fifth Edition.