Ensiling and subsequent ruminal degradation characteristics of barley tea grounds treated with contrasting additives

Abstract

The objective of this experiment was to determine the ensiling characteristics and in situ degradation of barley tea grounds (BTG) treated with contrasting additives. The BTG was ensiled without additive (control), or with mixtures of lactic acid bacteria and Acremonium cellulase (LAB + AUS), formic acid (FA), and sodium hydroxide (NaOH) for a period of 60 days. Three ruminal-fistulated steers were used to determine in situ degradabilities of dry matter (DM), crude protein (CP) in the BTG and its silages. In the LAB + AUS treated silage, the pH value (P<0.001) and ammonia-N content (P=0.007) were lower and the lactic acid content (P<0.001) was higher than the control. The FA and NaOH treated silages were well preserved as indicated by low ammonia-N content (P=0.007), no propionic acid and butyric acid. The LAB + AUS treated silage had higher rapidly degradable fraction of DM and CP than the control and BTG (P<0.001). The NaOH treated silage had higher contents of rapidly degradable fraction, slowly degradable fraction and effective degradability of DM and CP than control and BTG (P<0.01).