Effect of Stage of Maturity and Cultivars on the Digestibility of Whole Maize Plant and its Morphological Fractions

A study was conducted on four maize cultivars to determine the dry matter and fibre digestibility as influenced by advancing plant age. Samples of maize cultivars Akbar, Neelum, UM-81 and IZ-31 were harvested at weekly intervals/ growth stages. The samples of morphological fractions such as leaf and stem were also collected at various growth stages. Whole mixed fodder and different fractions of maize plant were analysed for their chemical composition and in vitro digestibility. The results showed that in vitro dry matter digestibility (IVDMD) of whole maize plant, leaf and stem decreased significantly with advancing stage of maturity. Digestibility of NDF, ADF, hemicellulose and cellulose decreased significantly in all plant parts with advancing plant age/growth stages. Maximum values for the digestibility of dry matter and various cell wall constituents were observed in leaf, followed by whole plant and stem fractions. Cultivars were observed to have significant effect of IVDMD and digestibility of NDF, ADF and cellulose in all plant fractions. The results indicated that digestibility of maize fodder was affected by stage of maturity and cultivars. However, maturity had a greater effect on digestibility in all plant fractions than did cultivars. Dry matter contents were found to be significantly and negatively correlated with IVDMD of whole plant and its leaf and stem fractions. Based on correlations, regression equations were computed to predict IVDMD.