THE INFLUENCE OF IRRIGATION MANAGEMENT AND GENOTYPE ON FIBER CONTENT AND IN VITRO DIGESTIBILITY OF NDF IN CORN PART PLANT

I. Fusaro, G. Canestrari, L. Fusaro, M. Chincarini, M. Giammarco, A. Palmonari, A. Formigoni, A. Gramenzi, G. Vignola, M. Fustini

Abstract: In several Italian regions climatic conditions are often not adequate to produce corn (Zea Mays) without an efficient irrigation strategy. Considering that forages quality is strictly related to fiber digestibility, it becomes more important to understand how the irrigation system affects fiber characteristic of the plants and it’s in vitro NDF digestibility (dNDF). The objective of this study was to investigate the effect of irrigation system on fiber characteristic of corn part plants. Two genetics were selected to have high (HD) and low (LD) digestibility of NDF and were subjected to 2 different irrigation systems, furrow (F) and sprinkler (S). Eight whole plants per each treatment were harvested at 33% of dry matter. Immediately after harvesting, the plants were divided into five fractions consisting of stalk, leaves and ears. The ears were then splitted into grain, cob and husk. All the samples were analyzed for fiber fraction (NDF, ADF, ADL) and digestibility of NDF (dNDF). NDF and ADF were not different between genotype and irrigation management in leaves, while ADL was influenced both genotype (P < 0.01) and irrigation management (P < 0.05). NDF digestibility and kD showed significant differences for genotype (P < 0.01) and
for irrigation system effect (P < 0.05). ADL of HD genotype in stalks was lower (respectively 4.24% in sprinkler and 5.16% in furrow irrigation system) than in stalks of LD (respectively 5.75% in sprinkler and 5.84% in furrow irrigation system) (P < 0.001), while dNDF (P < 0.001) and kd (P < 0.05) were influenced only by genotype showing the higher digestibility of dNDF in HD genotype. Cobs were not different in NDF, ADF and ADL, while DM (P < 0.05) and dNDF (P < 0.001) were influenced by irrigation system. We can conclude that higher fiber digestibility of the plant is mainly due to the genotype effect, even if is possible to obtain better results combining appropriate genetic and irrigation system.

Keywords: corn silage; digestible NDF; genetic; irrigation system

Date published: 2017-09-04