Corn silage constitutes the main forage base in the predominant US dairy production systems. The reasons have been the highly beneficial growing conditions, combined with the energy density contributed to dairy cow diets. Growing corn, however, also demands the right environmental conditions. As a result, some dairy producers also grow alternative forages to use when corn yields are lower than expected particularly in warmer and drier regions of the country.
Aside from sorghum silage, one other alternative that has been explored is pearl millet (Pennisetum glaucum). Because of its origin (Africa), pearl millet is adapted to grow in drier areas of the world, thriving in low fertility soils, and warmer temperatures. It is thus a very good forage “insurance” for warmer areas of the US where environmental conditions may challenge the growth of corn for silage.
Main characteristics of pearl millet as a crop
Pearl millet is a summer crop that adapts well to double cropping and rotations. Other advantages are that its long root system allows the plant to reach deep nutrients in poor sandy soils. It has also fair resistance to pests and does not have the problem of prussic acid toxicity in cattle when its frost stricken. It is recommended to harvest more than once during the season in order to achieve even greater yields than forage sorghum.
There are newer improved varieties of pearl millet that can even yield similar forage tonnage compared to sorghum with just one cut. These new varieties include the brown mid-rib trait (BMR) resulting in higher digestibility when compared to conventional pearl millet varieties. Past research has reported the same production in dairy cows replacing 10% of the corn silage in the diet with pearl millet silage.