Environmental Factors Affecting Corn Quality for Silage Production

Corn silage is a major ingredient of diets for dairy cattle. Environmental factors can affect the yield and composition of corn silage. Drought and heat are two common environmental factors that affect silage yield and quality. Corn silages with low concentrations of dry matter, high concentrations of protein, high concentrations of fiber, and low concentrations of starch indicate that the crop was harvested too early, that abiotic stresses affected the structure of the plant, or a combination of both. Drought stress during vegetative stages does not affect yield and nutritional composition as much as during reproductive stages. High environmental temperatures (>35 °C) can also induce kernel abortion. The effects of abiotic stresses on cell wall composition are less clear. Drought stress would likely increase fiber digestibility, whereas heat stress would decrease fiber digestibility. These statements are somehow contradictory in the sense that drought stress and heat stress likely occur simultaneously. Management practices, such as hybrid selection and planting date, should be considered to avoid silking and early kernel development during season of very high environmental temperatures.