The use of methane inhibitors could be one of the many measures that will aid a reduction in emissions from livestock farms.
Research has been conducted internationally using these products, but Teagasc has conducted its own research using the winter-milk herd at Johnstown Castle.
Methane inhibitors only remain in the rumen for around three hours which means that continued access to the them is required.
More research is need for spring-calving grazing systems as the inhibitors can only be fed during milking and their affects wear off after around three hours.
For the first three hours the inhibitors have similar results to the winter-milk system, but on average, over the day, there is a reduction of between 5-6%.
Methane inhibitors
Two experimental diets were set up with the winter-milk system at Johnstown Castle using the product 3-NOP.
This is the first of these products to be tested in an Irish production system.
The diets in the experiments had the same level of grass silage, maize silage, and concentrate supplementation, with the inclusion and exclusion of 3-NOP being the only difference.
The cows were only fed the 3-NOP inhibitor while they were on their winter diets, so these results are only from that period.
Control Additive Milk yield (kg/day) 29.8 30.4 Protein (%) 3.51 3.57 Fat (%) 4.60 4.63 Milk solids (kg/day) 2.45 2.50 Methane (g/day) 447 330 Methane (g/kg/MS) 182 132
The trial, which was conducted over the winter of 2022/23, found that milk yields were quite similar, but protein saw a slight increase as did fat percentage with the inhibitor-fed cows.
This resulted in a 2% increase in milk solids performance for the cows on the additive, and methane from these cows was also reduced by 26%/day and by 27%/kg of milk solids (MS).
Speaking at the event, Michael Dineen said that it is promising that the inhibitor stood up to the experiments at Johnstown Castle and that it works effectively for winter-milk cows.
Dineen added that this is just one of the measures that can be used to reduce methane production from ruminants, with economic breeding index (EBI), maximising grass in the diet, along with others contained with the marginal abatement cost curve (MACC).