9:00 AM - 9:15 AM
[IYS-01] Prediction of total-tract starch digestibility using fecal starch content in fattening Japanese Black cattle
Objective: The aims of this study are to develop a method for estimating total-tract starch digestibility (TTSD) from feces of fattening Japanese Black cattle and to evaluate the developed equation against that obtained from studies conducted in other countries. Methods: Seven heifers and 15 steers of fattening Japanese Black cattle were used, and TTSD was measured in a total of 61 cattle by repeating the trials. A linear regression model was developed to estimate TTSD from fecal starch (FS) content. Results: A strong negatively linear relationship between TTSD and FS was observed, and the equation for estimating TTSD was obtained: TTSD (%) = 99.6 (%) - 0.83 × FS (%DM), N=61, R2 = 0.87, P<0.001. The slope of the regression equation obtained from fattening Japanese Black cattle (-0.83) was significantly greater (P<0.001) than that from fattening cattle conducted in other countries (-0.47). This may be due to higher DM indigestibility and lower dietary starch content in Japanese Black cattle compared to those in cattle in other countries. Therefore, the developed method using FS content could be used to monitor TTSD in fattening Japanese Black cattle.