Possible drought in NZ? Do your figures first.

With dry conditions hitting a large part of the country we often hear advice from ‘Dairy Specialists’ that we need to be drying off cows and culling stock.

While this is a good way of trying to extend what pasture you do have it is also very important to review the figures and costs of drying off cows and what impact this potentially has to the bottom line. This needs to be reviewed carefully before any decisions are made, as often the hidden costs of drying cows off are not fully considered and the net result can be an increase in total costs. If a cow is only producing 10 litres of milk many people would consider drying her off, but when reviewing the numbers, often you will find this is not the best option.

Lets use a basic example to review:
10 litres at 10% milk solids = 1kg MS. Assuming a milk price of $6 ( for easy math and some comfort in return) that cow is returning 6/day.

To produce this milk we may be feeding around 14kg DM. We assume this 14kg is made up of 8kg pasture ( at $0.25/kgDM) 3kg silage ( at $0.40/kg DM) and 3kg Supplement ( at $0.45/kg DM).

Total feed costs equate to approx. $4.55/cow per day. ( feed costs will be generally cheaper than this depending on each farm system).

When we look at this against the 1kg milk solids she is producing its not a pretty scenario with a return over feed cost of only $1.45. However we need to also look at the benefits.

This cows is being fed more than the energy requirement to produce this 1kg MS so effectively has surplus feed which will be used to gain weight or at least maintain the current condition ( worse case). This also allows for a quick change should/when we get some rain and the pasture grows, which will reduce the overall feed costs further.

It also ensures that the cow is in optimum condition come May/June when we traditionally look at drying cows off. This in turn helps set that cow up for the next season and means that over the dry period feeding can be done at just maintenance levels rather than try to
add condition, which is expensive.

Now lets review cost of drying that cow off: Vast majority of cows in NZ will be on a dry cow ration of 9\12kgDM/day. Assuming we have some pasture on a runoff block or on the milking platform and can feed just pasture we have a dead cost of 10kg at $0.25/kg = $2.50/cow/day.

(originally published March 28, 2019)