HAVE DAIRY FARMERS MADE PROGRESS IN REDUCING GREENHOUSE GASES?

The quest and responsibility to reduce greenhouse gas (GHG) emissions remains paramount for all sectors, also the dairy industry. As the bulk of GHG is produced before the farm gate, it is logical that investigations of progress in mitigation should start there. However, direct measurements of all influencing factors are not possible in South Africa, and for that matter also not in most countries. Thus, estimates are based mostly on a combination of measurements, directives from elsewhere such as from the International Panel for Climate Change (IPCC) of the UN, and trends or observations over time. In the analyses below, trends were supplemented with the official estimates of the SA Department for the Environment, Forestry and Fisheries which were reported to the IPCC in 2010 and 2017.

It is known that efficiency of milk production, whether obtained by more milk per cow, or the same amount with less cows will result in less GHG per litre milk. To that effect, the following table was compiled with trend calculations and results obtained from the publication Lacto Data.

                   Milk production statistics in South Africa between 2009 and 2023

The errors of estimate could be >10%

The table shows the well known reduction in dairy producers and the concomitant increase in size of herds per farm. This change in farm dynamics resulted in an initial increase in cows as those from the smaller production units were purchased by larger operations, but since about 2017, the numbers apparently stabilize due to reasons which are not relevant in this discussion. Despite this stabilization, milk production increased almost linearly, which implies that milk yield per cow increased, and therefore efficiency of production, which implies that GHG per litre milk improved.

This indirect observation is supported by the following:

SA Government Tier 1 and 2 estimated dairy cattle emission numbers and some actually measured/calculated from pasture-based farms:

Government Reports to the IPCC for Dairy:

2010 = 179 Gg CH₄/annum

2017 = 123 Gg CH₄/annum; the total GHG emissions being 3.72 MT CO₂eq/annum.

[From the table, the 2017 milk production was 3.25 MT, which implies that the CO₂eq emissions per litre milk was 1.145 kg CO₂eq/L milk (3.72/3.25]

Actually measured/calculated (400 observations) in 2021-2023 on pasture-based farms: 1.02 to 1.57 (mean 1.30) kg CO₂eq/kg FPCM. These numbers concur with those reported from Oceania, the UK and some European countries. The large variation, however, implies that there should be much improvement on some farms, which must be pursued.