Changing Laws And Correlations Of Shearing Force And Feed Characteristics Of Maize Plant

The objectives of this study were to investigate the changing laws and the relationships of shearing force and nutritional ingredient of growing maize plant, and further prove confirm that shearing force is one way of evaluating nutritional ingredient of forage. Three generally planted species of maize, LD661, ND108 and ZD958 was been chosen.Mobile equipment for shearing force to be used specially for roughage was been advanced development at fist, which is range at 0-2000 N, and suitable for sample whose diameter from 0 to 35 mm. Warne-Bratzler's apparatus of measuringshearing strength is generally used by intemational. The system studied in which the teehnology of the characteristics of roughage needs is used combines the principle of Wame-Bratzler's apparatus of measuring shearing strength with the technology of sensor. The equipment was been proved to be excellent through standard test,and the test and measurement. At present, a new type practical patent was been patented by institution, and the number of certificate is 1676330.The shearing force, linear density and chemical compositions of leaf, pericladium and stem every 24 plants of each species were measured at 5-day intervals during the 78-108th d, and the same indication was measured at the milk stage, dough stage and physiological maturity stage. DM, OM, CP, EE, NDF, ADF and GE was been determined, meanwhile, three sheep fitted with permanent cannulas in rumen, were used to determine In Situ degradability in 48 h of the nutrients of three chief vegetable organs at the three different maturity stage.The results showed that linear density and shearing force of stem linear increased with maize growth and there was different among varieties (P < 0.05). Shearing force of pericladium linear increased (P < 0.05), and the linear density of leaf and pericladium linear reduced (P < 0.001). There were significant correlations of shearing force with linear density of pericladium and stem (P < 0.05).The contents of DM, OM, NDF, ADF and GE in pericladium and stem on the base of fresh matter linear increased, contents of CP linear reduced, there were different among varieties (P < 0.05), and the contents of DM, OM, NDF and ADF in leaf had a linear increase (P < 0.05), during the 78-108th d. of maize growth. Significant correlations were found between shearing force and chemical compositions of pericladium and stem (P < 0.05). In Situ degradability of pericladium decreased with increasing shearing force (P < 0.05), and that was different among the three chief vegetable organs (P < 0.05): leaf > pericladium > stem. While, the shearing force, linear density and other morphological characteristics, and the chemical compositions of leaf, pericladium and stem of three repeat of maize were measured, showing that the feed characteristics of maize plant were declined during the experiment. And to harvest at the milk stage and the dough stage is better than the physiological maturity stage, and the milk stage is the best.The shearing force, chemical compositions and In Situ degradability of maize plant is still dynamic, during the 78-108th d. stage. Shearing force can be employ to predict the chemical composition and utilization of growing maize plant, while take the different organ and variety into consideration. To harvest at the milk stage and the dough stage is better than the physiological maturity stage.