The bromatological composition of four sunflower genotypes (M742, MG4, PM92007 and VDH483) used for producing seed, ensiled at different harvest ages (90, 97, 104, 111 and 118 days) after sowing, was used to determine the best time to ensile. Differences among ages and cultivars were found for dry matter of the genotypes. The crude protein values varied from 8.3 to 12.6% for the original sample and from 9.4 to 12.9% for the silage. A decrease (P<0.05) in the soluble carbohydrate values for the ensiled genotypes was observed. The ether extract values varied from 2.2 to 13.3% for the original sample and from 3.0 to 17.9% for the silage. The values of hemicellulose and lignin decreased with the ensiling process, suggesting the fibrous fractions contributed, as additional substrate source, for fermentation. The lactic acid values decreased with the plant maturity stage. The dry matter in vitro digestibility decreased with the plant maturity. The best time to ensile, based on the quality of the sunflower genotype M742, MG4 and VDH483 silage, was at 104 days of age and for the genotype PM92007 silage was at 111 days of age.
sunflower; age of harvest; cutivar; in vitro; dry matter; digestibility; pH
