An in vitro study of the total amount of cumulative gases produced of alfalfa, hay, straw, silages and grass masses from different cattle farms in Bulgaria

The amount of gas formed in different types of bulky coarse forages at 24h and 48h incubation is different and depends on the rate of dry matter decomposition. The mean values of the alfalfa samples from the three farms was 244.5 ± 43.6 ml/g DM at 24 h incubation and 288.4 ± 50.1 ml/g DM at 48 h incubation. The mean values of the corn silages samples from the fourteen farms was 199.8 ±19.3 ml/g DM at 24 h incubation and 259.3±18.2 ml/g DM at 48 h incubation. The mean values of the senages, grass masses samples from the eight farms was 115.1 ± 11.07 ml/g DM at 24 h incubation and 162.4 ± 15.6 ml/g DM at 48 h incubation. The mean values of the straw samples from the twelve farms was 144.6 ± 56.2 ml/g DM at 24 h incubation and 205.1 ± 56.6 ml/g DM at 48 h incubation. The mean values of the alfalfa hay samples from the five farms was 208.3 ± 28.3 ml/g DM at 24 h incubation and 239.9 ± 33.2 ml/g DM at 48 h incubation. In the case of forages - straw, silage and haylage, the gas formed at 48 h incubation was 29.74% to 41.80% more compared to 24 h. The amount of gas formed as a consequence of fermentation processes in ruminants studied by the “in vitro” gas production method depends mainly on the specific chemical composition and structure of the feed.