Why starch is a critical quality criterion to consider when choosing a maize hybrid

When selecting a forage maize hybrid most growers consider starch content and starch yield as two criteria of importance, along with others such as maturity and area of adaptation.

This approach serves farmers well since starch accounts for a disproportionately large percentage of the energy yield and feeding value of maize silage, explains Andy Stainthorpe, UK & Ireland Business Manager for Pioneer Hi-Bred.

‘The total feeding value of maize silage is best characterised by its content of metabolisable energy (MJ ME/kg DM) since this is what is available to the animal through digestion. In typical maize silage most of the energy originates from starch, sugar and easily digested “plant cell contents”’ explains Andy. However it is important to also not forget that starch in maize silage is a very useful component of a ruminant’s overall ration simply because it degrades more slowly and therefore poses less of an acidosis risk than when cereal starch is included at an equivalent rate.