Alfalfa Feeding Guidelines
Alfalfa is arguably one of the most variable feeds on the farm. This is due to field-by-field variations in the age of stand (grass content), harvest maturity and moisture, fiber digestibility affected by the growing environment and issues surrounding fermentation and palatability.
Producers can improve the consistency and quality of alfalfa silage by focusing on harvest maturity. The use of the PEAQ stick (predictive equations for alfalfa quality) for assessing alfalfa maturity and NDF levels has been around for decades, and is a tool more growers should be using to monitor plant maturity. Alfalfa is fed to ruminants to provide energy, protein and fiber. Alfalfa silage with a high RFQ (above 170) will have relatively lower levels of ADF, NDF and effective fiber (peNDF). It will also have high levels of crude protein, much of which is in the readily soluble form. Properly managed, high-quality alfalfa, with an acceptable range of RFQ (150-170) allows for easier ration balancing, proper levels of effective fiber and acceptable levels of soluble protein. It can also minimize the off-farm purchase of protein supplements.
Careful attention to NDFD and ash content will help ensure a digestible crop with less fermentation issues. Most nutritionists would prefer that producers delay alfalfa silage harvest and deal with lowered digestibility than suffer with feeding rained-on, poorly fermented silages. Field experience has also conditioned nutritionists to target ideal moisture levels at around 60% to reduce protein degradation and the potential for clostridial alfalfa silages.