The importance of factors of variation on the nutritive value of silage maize

It is difficult to determine the energy value of forage maize with a satisfactory level of precision. The effects of the climatic conditions are not yet sufficiently known. Although the influence of the genotype is better known it should be determined with greater precision, especially in varieties in which stem and cob do not mature synchronously (stay-green effect). The Swiss Federal Research Station for Animal Production of Posieux has launched a research project to study the effect of three factors (environment, variety, stage of maturity) on the nutritive value of forage maize. Of the three factors under investigation, stage of maturity caused the greatest differences in digestibility. The obtained results show the importance of the appropriate moment of harvest. Environmental factors first of all affected the evolution of the dry matter content in the two plant fractions cob and vegetative parts. Contrary to our expectations, this factor had not a great effect on quality. With respect to genotype, observed differences were significant. However, it was not the stay-green variety which showed the best digestibility.