Dry off time - when is the right time?

'It starts here', is the familiar welcome at a Fonterra farm tanker entrance. It also applies to the end of this season's lactation in relation to next year's production. Each lactation does not start at calving but at the preceding dry-off time.

The dry period is valuable as it allows the cow to divert energy from milk production to self preservation, the growing needs of the fetus and importantly, regeneration of spent udder tissue. With a healthy, fully 'celled-up' udder and good body condition, she is ready for a good lactation.

The decision of when to dry cows off will be based on your financial budget, your milking platform feed budget, the body condition score of cows and your wintering feed budget. There is always pressure from financial managers to meet short-term targets but this can be at a cost to next year's production – this is a point that can be difficult to convey.

There are no free lunches. If you rob some body condition during this season it has to be put back on and if not, you simply transfer the loss to next season. This may then compound into poor production, poor reproductive performance and other health issues as well.

The established rule of thumb is that you dry off in the condition you wish to calve, and a Body Condition Score (BCS) of five is Dairy New Zealand's recommendation. The problem is not many cows are in this condition at present.

To get cows to gain weight you have to feed them more or milk them less. This means growing more feed for example through irrigation or nitrogen, using supplements like grass, maize, whole crop silage or purchasing grain or PKE grazing. The choice is based on practicality and cost.

If these options do not appeal, then reducing the stocking rate will have the same effect. For example, if you are feeding 12kg of pasture and reduce the stocking rate by drying off 20%, the balance of the herd then have 15kg each. It would be no surprise if total production did not decrease and cow condition improves.

If you looked through your recent herd test results and calculated the production from the bottom 20% it may only be 5 -10% of the total. These cows are currently inefficient at converting grass into milk but may be in good condition. If you have light-conditioned heifers and no extra feed, they can be put on once-a-day milking to gain some condition. This is likely to save around 12MJ energy per day and on that basis for a crossbred it will take until the end of the season to put on one BCS unit which is 35kg. This illustrates if action needs to be taken it must be done NOW.

If buying supplements do your sums first to establish the return is real and this option is better than drying off.

Winter feed budget
Do this carefully and allow for wastage. When winter nutrition is good you can get an extra half a condition score gained in June. Do not count on any gain in July. If your winter feed is marginal, cow condition will have to be gained on the milking platform.

Visit your cows at least weekly while they're out grazing
Do not run down your home pasture covers. Look back over the last few seasons and ask yourself if 1900kg/ha was a safe level on 1 June. Would spring have been easier if there was an extra 100kg or more?

We are not very good at transitioning our cows back to pasture at calving (because there is not enough of it) when they are under great stress, but we are all aware of the benefits of transitioning onto crop. Please note that the Animal Welfare Code 2010 (Dairy Cattle), which is law, contains the following Minimum Standard for Food: "When the body condition score of the animal falls below 3 (on a scale of 1-10), urgent remedial action must be taken to improve condition."