Birdsfoot trefoil can be grazed, cut for hay, or used for silage. It will thrive in areas that alfalfa and other forage legumes cannot grow due to soil acidity and moisture. Soils with low pH, poor drainage, poor native fertility, or fragipans prone to heaving are suitable locations for planting birdsfoot trefoil. In similar well-drained, fertile soils, birdsfoot trefoil will not yield as well as alfalfa – 50 – 80% of what alfalfa would do on the same ground. Birdsfoot trefoil can reseed itself and does not cause bloat in animals.
Total digestible nutrients will be greater than alfalfa depending on the growth stage, and trefoil will not lose quality with maturity as fast as alfalfa. Even after going to seed, forage quality and protein content remain high. Companion grasses have seen increased yield and protein when planted with birdsfoot trefoil. Research shows more significant daily gains and meat yield per acre in heifers and sheep than alfalfa. The most tolerant legume of wet springs, dry, hot summers, and cold winters, birdsfoot trefoil, is also low in estrogens that cause fertility problems.
A high concentration of tannins composed of procyanidins protect proteins from rumen degradation, reduce urinary N excretion, prevent bloat, and boost the effectiveness of worming medications. The level of tannins can vary according to multiple factors and will change from season to season. Greater than 1% of total diet DM comprised of these condensed tannins will reduce feed intake, digestibility, weight gain, and wool growth. Compared to other legumes such as sainfoin, birdsfoot trefoil contains less fiber and more degradable protein. Organic matter digestibility is comparable to alfalfa and sainfoin. Dairy cow and ewe diets containing trefoil have increased milk yields, protein, and solids-not-fat compared to diets containing alfalfa or red clover silage. Grazing meat sheep and lambs on forage legumes rather than on ryegrass will make it possible to increase the growth rate and reduce time to finishing without a decrease in quality.