Short communication: Impact of the intensity of milk production on ammonia and greenhouse gas emissions in Portuguese cattle farms

Abstract

The aim of this study was evaluate the relationship between the intensity of milk production for a wide range of Portuguese commercial cattle farms and NH 3 and greenhouse gas (GHG) emissions from manure management and enteric fermentation. A survey was carried out at 1471 commercial dairy cattle farms (Holstein-Friesian) and the NH 3 , N 2 O and CH 4 emissions at each stage of manure management were estimated as well as CH 4 losses from enteric fermentation. Gaseous emissions were estimated by a mass flow approach and following the recommendations of IPCC guidelines. The manure management and enteric fermentation in a typical Portuguese cattle farm contributes with 7.5±0.15 g N/L milk produced as NH 3 and 1.2±0.22 kg CO 2 equivalent per litre of milk as GHG. Increasing milk production will significantly reduce NH 3 and GHG emissions per litre of milk produced. It can be concluded that a win-win strategy for reducing NH 3 and GHG emissions from dairy cattle farms will be the increase of milk production on these farms. This goal can be achieved by implementing animal breeding programs and improving feed efficiency in order to increase productivity.Additional key words: dairy cattle; enteric fermentation; gaseous emissions; manure management.

The possibility of greenhouse gas emissions reduction from the dairy cattle farms

“…Changes in the TMR, regarding the role of carbohydrates in reducing CH4 emissions are suggested by Haque et al [2014]. Pereira and Trindade [2015] indicated that besides the better feed-use and its improved digestibility, increased cow productivity in the surveyed farms significantly reduced emissions per 1 liter of milk. With capacity of 10.000 liters of milk per cow per year there was 25 percent less compared to the 6.600 liters per year.…”