Effect of the ratio of maize cob and husk to napier Pakchong 1 silage on nutritive value and in vitro gas production of rumen fluid of Thai native cattle

Abstract

© CSIRO 2017. The present study evaluated the chemical composition and in vitro ruminal digestibility of napier Pakchong 1 silage combined with maize cob and husk in different ratios. The napier Pakchong 1 grass was harvested at 45 days of maturity. The napier Pakchong 1 grass was ensiled with maize cob and husk at ratios of 1:5, 1:10 and 1:15. Three rumen fistulated Thai native cattle (White Lamphun cattle) with an average weight of 154 ± 4.7 kg were used to determine ruminal digestibility by in vitro gas-production technique. Gas production was recorded after incubating for 2, 4, 8, 12, 24, 48, 72 and 96 h. The microbial biomass yield was determined after incubating for 24 h. DM, NDF and ADF of maize cob and husk mixed with napier Pakchong 1 silage declined by increasing the proportion of napier Pakchong 1 grass, while gas production after 4-10 h of incubating maize cob and husk mixed with napier Pakchong 1 grass increased by increasing the proportion of napier Pakchong 1 grass. The metabolisable energy, organic matter digestibility and microbial biomass yield did not differ among the different ratios. The results of the study suggested a recommended ratio of maize cob and husk to napier Pakchong 1 grass of 1:10. The ensiling fermentation increased the proportion of protein in the roughage, which lead to increased in vitro gas production of roughage.