Effects of added urea and ammonium polyphosphate to corn stover silages on animal performance.

Abstract

OVER 80% of the corn crop is harvested for grain (Coppock and Stone, 1968). Approximately 50 to 60% of the dry matter content of the plant is removed when harvested for grain (Johnson et al., 1966); consequently, the vast amount of vegetation (corn stover) remaining in the field offers a large potential source of energy for ruminant animals. Ensiling the vegetative material reduces field losses and may produce a more palatable feedstuff than if utilized by grazing. Corn stover contains considerable potential energy; but in regard to nutrient requirements it may be deficient in nitrogen, minerals and vitamins. Two of the more limiting nutrients are nitrogen and phosphorus ; thus, the use of additives to improve the nutrient content and utilization of corn stover silage warrants investigation. In a preliminary study, Holstein heifers fed corn stover silage supplemented with protein, minerals and vitamins gained nearly 0.50 kg per day (Colenbrander, Müller and Noller, 1967). An earlier study indicated that the addition of ammonium polyphosphate (APP) to stover silages produced a favorable improvement in intake and growth response of dairy heifers when compared to stover silage with no additive (Lonsdale, 1970). Although research on corn stover silage dates back over 50 years (Sherman and Bechdel, 1918), documentation in scientific literature on the chemical characterization and feeding value is limited.