What measurement is most critical in determining forage quality?

Understanding forage quality is crucial for animal nutrition and overall livestock health, and the maturity stage of the forage is a key indicator of its quality. As plants mature, several physiological changes occur that directly impact their nutritional value. Generally, younger forage is higher in protein, minerals, and digestibility, making it more nutritious for livestock.

When plants reach full maturity, they tend to have increased fiber (specifically lignin) which can lower digestibility and protein levels, making it less palatable and less nutritious for animals. This is why maturity stage is often emphasized in evaluating forage quality—certain stages yield higher-quality forage that better meets the dietary needs of livestock.

While other factors like moisture content, pH level, and protein percentage are important in evaluating forage as well, they do not capture the broader implications of the plant's growth stage on its nutritional profile as thoroughly as maturity does. Moisture content affects the storage and fermentability of forage, pH can influence fermentation processes in silage, and protein percentage informs on the nutritional content, but these factors are often directly influenced by and change alongside the maturity stage of the plants.