Effect of drought stress on in situ ruminal starch degradation kinetics of corn for silage

The objective of this study was to determine the effect drought stress on in situ ruminal starch degradation kinetic parameters corn for silage. Five commercial hybrids silage were utilized. experiment designed as a split-plot within randomized complete block design with 4 blocks. Eight plots blocked and randomly subjected watered (W) or non-watered (NW) treatment. Within each block, split into 5 sub-plots, which 1 assigned. Before planting, all irrigated 150 mm water ensure consistent emergence seedlings. After pre-planting irrigation, NW not ever again. W 75 when crop showed 2 visible leaves, 6 pre-tasseling 45 every week, thereafter, total 8 weeks (360 post-tasseling). Three ears from subplot collected crops between 1/4 3/4 milk-line stage maturity. Kernels shelled by hand dried. degradability determined ground (4-mm) grain samples placed Dacron porous bags. All bags immersed rumen 3 rumen-cannulated cows fed totally mixed ration containing 32 % silage, alfalfa hay, 65 concentrate mix (DM basis). Bags incubated 0, 4, 8, 12, 24, 48 h. Water did affect fraction instantly degraded (203 mg/g), potentially (759 undegraded (38 differential rate (0.0669/h). Corn any these no interactions existed irrigation treatment hybrid. In conclusion, had