Effects of Potato By-products Containing Glycoalkaloid on Rumen Fermentation Characteristics

Abstract

The present study was conducted to investigate the effects of feed types (powder vs. pellet) from potato by-product containing glycoalkaloid on rumen fermentation with different rumen pH (low vs. high) using in vitro technique. Rumen fluid was collected from two cannulated Hanwoo heifers before morning feeding (high rumen pH at 6.71) and 3 h after feeding (low rumen pH at 6.20). A 0.5 gram of powder or pellet from potato by-product was incubated in the rumen buffer for 48 h at 39℃. Four replications for each treatment were used along with two blanks. Pellet had higher (p<0.05) the immediately degradable fraction, the fractional degradation rate, and the lag phase than those of powder. However, feed type had no effects on the potentially degradable fraction and the total degradable fraction. In fermentation characteristics, powder had higher (p<0.05) concentrations of ammonia-N, total volatile fatty acid (VFA), and acetate than those of pellet. In addition, a high rumen pH had higher (p<0.05) concentrations of ammonia-N and acetate, but lower (p<0.05) total VFA concentration than those of a low rumen pH. The interaction effects between feed type and rumen pH were found on the total degradable fraction and concentrations of ammonia-N, total VFA, and acetate. The present study concluded that generally feed type had no effects on rumen degradation kinetics, but potato by-product in the powder form is recommended due to produce higher fermentation characteristics than in the pellet form.