In vitro degradation and in vivo digestibility correlation of two tropical grasses

Abstract

The present research was conducted to compare the in vitro- degradation and in vivo digestibility, for which eight castrated lambs were used. The lambs received rhodes grass and green panic grass hay in four stages of maturity. No significant differences were found in the digestibility among treatments. The analysis of  in vitro degradation for fiber in neutral detergent with 24 and 48 hours of fermentation on the model for analysis was factorial 2 x 4 x 2 (species x stages of maturity x fermentation periods), showing no statistically significant differences (P > 0.05). The regression equations and the correlation coefficients produced r values considered from medium to high. The highest correlation coefficient was obtained between the relative degradation rate of 24 and 48 hours, and forage TDN content (r = 0.84), with a reasonable standard deviation of the estimation (Sy’x = 3.92).