Abstract

The objective of this study was to evaluate the effects of different levels of Fructus agni-casti (FAC) on in vitro gas production (GP), organic matter digestibility (OMD) and net energy lactation (NEL) using an in vitro gas-production method. Two rumen-fistulated sheep were used in the experiment. The sheep were fed 60% alfalfa hay and 40% concentrate feed twice daily. Five different levels of FAC were added to the concentrate (CON). The volume of gas produced was recorded at 2, 4, 8, 12 and 24 h after incubation. In this study, the GP-improving effect occurred at 2 h of incubation in FAC₃ and FAC₄ groups. Degradation of the water-soluble carbohydrates promoted the concentrate feed with FAC (3 and 4% level) additions. However, the GP-reducing effect occurred from 8 to 12 h of incubation in all the treatments. It was shown that, the concentrate feed with FAC addition reduced degradation of storage polymers such as starch. In addition, GP (at the 24 h), OMD and NEL were not affected by supplementation with FAC.

Key words: Vitex agnus-castus, essential oil, feed digestibility, in vitro gas production