Contribution of lactic acid bacteria to rumen metabolism and the prokaryotic microbiome when applied as either a silage inoculant or as a direct-fed microbial supplement in lactating dairy cows

The capacity of agricultural systems to optimize forage production for livestock is dependent upon the effective preservation of crops, which ensures year-round supply of nutrients. Preservation of fresh crops through ensiling can be enhanced through inoculation with bacteria that produce lactic acid, which inhibit the spoilage of forage under anaerobic conditions. In this study, lactic acid bacteria were added to forage at either ensiling or feeding of forage to lactating dairy cows. Lactic acid bacteria altered the ensiling fermentation, rumen metabolism and microbiome, but had no effect on feed intake or milk yield was measured. Understanding the processes underpinning the interactions between silage biochemistry, inoculants, the rumen microbiome and fermentation kinetics is key to identifying novel ways to exploit microbes (and their biochemical processes) in order to maximise efficient dairy production