MANAGING DRY OFF
Planning

Consultation with your veterinarian can help determine the date of dry off. The dry period needs to be of sufficient length to allow the udder to regenerate.

Also influencing the decision when to dry off are:

Condition score
  • Cows need to be dried off in sufficient condition and with a long enough dry period to be at Condition Score (CS) 5 by calving.
  • Cows calving at a lower CS will produce less and have more reproductive problems. A cow calving at CS 4 produces 15kg of milk solids (MS) less than if she calved at CS 5.
  • Dry cows must be fed like lactating cows to gain one CS in 30-40 days.
Pasture cover
  • Cows must be dried off according to feed budget targets.
  • In general, herd demand is greater than winter growth, therefore pasture cover will tend to decline.
  • More feed is available at the start of calving if a slow winter rotation is established early in autumn. If, however, cows need to gain condition, more grass (or supplements) will be required and a faster rotation needed.
Milk production and Somatic Cell Count (SCC)
  • When average herd production drops below 10 L/cow/day, start planning dry off. Dry off low CS cows early, to allow more time for feeding to increase CS.
To avoid SCC grades:
  • Dry off high SCC cows (>500,000 cells/mL) early to avoid the risk of grading
  • Dry off low producing cows early before their SCC increases as they dry themselves off naturally. Low producers are cows producing less than 0.4kg MS/cow/day (approximately 5 L/cow/day for Friesian and 4 L/cow/day for Jersey cows)
  • If the Bulk Tank Somatic Cell Count (BTSCC) is greater than 350,000 cells/mL, dry off selected cows as above, or dry off the whole herd.
Dry off procedures
Milking
  • Dry off low yielding and high Somatic Cell Count (SCC) cows early – especially if at risk of grading for SCCs.
  • Once daily milking is NOT strictly necessary in the final week, particularly if the herd is already below 10 L/cow/day.
  • Do not practice ‘skip a day’ or every other day milking. This increases milk SCCs and susceptibility to mastitis.
Feed intake
  • For cows giving more than 10 L/day, reduce or alter feed intake in the final week before dry off. A change in the nature of the diet rather than a reduction can stimulate the cow to dry off. For example, if a herd is given a high carbohydrate supplement such as maize silage, increasing the proportion of maize and cutting down on pasture (and hence protein) intakes can reduce milk production while maintaining energy and condition.
  • If yields are below 10 L/day, further milk yield reductions are not required before dry off. DairyNZ studies indicate that cows producing 11 L/day before dry off have no more mastitis than those producing 4 L/day.
  • Reduce intakes to maintenance levels (not below) for seven days after the final milking before increasing feed to gain condition.
  • Keep water available at all times.

A study of factors around dry off3 and the dry period that influence SCCs in the following season showed an increase in SCCs on farms where feed was restricted. This may have been due to the effects of nutritional stress or loss of condition on the cows’ ability to resist new infections during the dry period. It is important to keep a balance between reducing the stimulus for the cow to produce milk and maintaining energy levels.

3
McDougall S. (2003). Management factors associated with the incidence of clinical mastitis over the non-lactation period and bulk somatic cell count during the subsequent lactation. NZVJ.