Effect of harvest time on the protein and energy value of wheat hydroponic green fodder

Abstract

The effect of harvest time (8, 10 and 12 days after germination) on the protein and energy value of wheat hydroponic green fodder was evaluated on the base of crude protein (CP), dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) content, and of organic matter digestibility (OMD), in situ dry matter, crude protein degradability, and in vitro gas production estimations. Data were analyzed according to a completely randomized design. Mean differences were detected using Tukey's test. The highest CP concentrations (21,4%; p<0,05) were obtained 10 days after germination, whereas NDF and ADF values were different (p<0,05) among harvesting times. Degradation of the soluble fraction (a) of DM was higher at day 8 and decreased at longer harvest times. On the contrary, the slowly degradable fraction (b) increased with plant maturity. This same pattern was registered with the CP degradation parameters. The highest OMD values were registered at 10 days after germination (p<0,05). Gas production from the a and b fractions of the feed was different among harvesting days (p<0,05), whereas the constant rate of gas production c and the metabolizable energy content were superior at 10 days after germination. The wheat hydroponic green fodder harvested at 10 days after germination had superior protein and energy values compared to their counterparts harvested 8 and 10 days after germination, which favors its utilization in ruminant nutrition.