Corn silage additives show in vitro methane-cutting potential

A new paper in Animals points to a potentially useful silage strategy for methane mitigation: adding Lactobacillus casei TH14 and hydrolysable tannin during corn ensiling. In the study, the additives changed silage fermentation characteristics and reduced methane production in an in vitro rumen model, suggesting that silage management could become one more lever for shaping both feed quality and environmental performance. (pubmed.ncbi.nlm.nih.gov)

The idea didn’t emerge in a vacuum. TH14 is a lactic acid bacteria strain first isolated from tropical silage in Thailand, and earlier work has linked it to improved fermentation quality in sorghum silage, sweet corn stover, cassava pulp, and rice straw systems. Separately, hydrolysable tannins, including chestnut-derived products, have been studied for their ability to alter rumen fermentation, protect protein during ensiling, and in some cases reduce methane formation. But the literature also shows a recurring caveat: responses are inconsistent, and benefits often depend on the forage matrix, tannin chemistry, dose, and whether findings come from in vitro or in vivo work. (pubmed.ncbi.nlm.nih.gov)

In this new study, researchers Rittikeard Prachumchai and Anusorn Cherdthong evaluated whole-plant corn silage after 21 days of ensiling in a completely randomized design with seven treatments and four replicates. The treatment structure combined molasses, TH14, and sweet chestnut (Castanea sativa) hydrolysable tannin at 20 or 40 g/kg dry matter. The abstract reports that silage pH differed significantly among treatments, with one treatment reaching the lowest pH, and that the additive combinations modified in vitro rumen fermentation while reducing methane production. That framing is consistent with earlier TH14 and silage inoculant studies showing stronger lactic fermentation and with prior tannin work showing lower methane alongside shifts in fermentation end products or microbial populations. (pubmed.ncbi.nlm.nih.gov)

Industry and research interest in this area is broad because methane reduction strategies that can be incorporated into routine feed preservation are attractive, especially where corn silage is already central to dairy or beef systems. Recent related studies have continued to test combinations of lactic acid bacteria, enzymes, and tannins across different by-products and forages, reflecting a wider push toward feed additives that improve preservation and lower emissions at the same time. At the same time, review literature has been cautious: tannins can suppress methanogenesis, but they may also affect fiber digestion, and hydrolysable tannins in particular raise more safety questions than condensed tannins when inclusion rates climb. (mdpi.com)

Why it matters: For veterinarians and nutrition-minded herd advisers, the bigger takeaway is that silage additives are increasingly being evaluated as metabolic tools, not just storage aids. If a silage inoculant-plus-tannin approach can reliably preserve nutrients, improve fermentation, and reduce methane without depressing intake or digestibility, it could influence ration formulation, sustainability reporting, and how feed interventions are discussed with producers and pet parents involved in food-animal care decisions. But this paper should be read as an early signal, not practice-changing evidence. In vitro methane reductions often don’t translate cleanly to live-animal performance, and veterinary teams will want to see data on palatability, rumen health, milk or gain outcomes, nitrogen use, and any toxicity concerns before recommending broad adoption. (pubmed.ncbi.nlm.nih.gov)

There’s also a practical formulation issue. The same mechanisms that may reduce methane, including altered microbial activity and binding interactions between tannins and nutrients, can become counterproductive if the dose is too high or the forage context is wrong. Reviews and comparative studies have repeatedly found that tannin effects are variable, and some methane reductions may come with tradeoffs in degradability. That makes dose selection, forage choice, and animal class critical if this line of work moves toward commercial application. (mdpi.com)

What to watch: The next milestone is in vivo confirmation, ideally in dairy or beef cattle fed corn silage treated with TH14 and chestnut tannin under production conditions. Watch for follow-up trials measuring methane, intake, digestibility, and performance together, because that’s where this concept will either become a useful nutrition tool or remain an interesting laboratory result. (pubmed.ncbi.nlm.nih.gov)