It has been claimed that consuming soya-extracted ‘milk’
drinks rather than feeding soya bean meal to cows to
produce milk is more efficient in terms of soya use (Whiting,
2019). The yield of soya drink ranges from 4.25 to 7.5 litres
per kg whole soya bean fresh weight, depending on the scale
of operation (Young, 2017). Based on information from the
UK Department for Environment, Food and Rural Affairs
(Personal communication, 2017), it has been estimated
that between 92,000 and 173,000 tonnes of soya bean meal
is used in dairy cow diets in the UK (Young, 2017). Total
milk production in the UK was 14,713 million litres in
2017/18 (Statista, 2019b), which can be calculated as the
yield of dairy cow milk being 85 litres per kg soya bean
meal consumed. Kroes and Kuepper (2015) calculated that
7 g of soya bean meal is needed to produce 200 ml of dairy
cow milk, or 28.6 litres per kg soya bean meal. The higher
relative use of soya in European dairy farming compared
with UK may reflect the greater abundance of grass growth
in the latter. Therefore, it seems reasonable to assume that
the yield of dairy cow milk in Europe is between four and
11 times higher than the yield of soya drink produced direct
from soya beans, depending on the extent to which soya
bean meal is used in dairy cow nutrition in different regions.
A further consideration is that dairy cow milk is made
from the meal co-product of soya oil production, with little
residual oil, whereas soya drink is made from whole beans.