Preparing for the dry cow period – pre-housing tasks
Full-time housing is only a matter of weeks away, writes Dr Aisling Claffey, Ruminant Nutritionist at Teagasc, who discusses tasks need to be considered to prepare for the dry cow period and set cows up for next spring.
Complete quality and mineral analysis of silage
It is imperative to identify and keep a bank of high-quality silage for buffer feeding in early lactation as required (typically equivalent of 2 bales/cow – 400 kg DM/cow). In-calf and weanling heifers will also need high-quality silage over the winter months to maintain target growth rates.
Mineral analysis is often overlooked, but it is critical that we identify suitable low Potassium (K) forage (< 2.0 % K/kg DM) for feeding to cows in the last 2-3 weeks before calving (c. 150 kg DM/cow).
Potassium negatively impacts on a number of the factors involved in Calcium mobilisation, including Magnesium absorption and the efficacy of the parathyroid hormone to respond to changes in blood plasma Calcium levels. Failure to address high K forages in the transition cow pre-calving diet will contribute to higher prevalence of sub-clinical and clinical milk fever in the herd.
These analyses often take a number of weeks to complete and for results to be returned to the farmer, giving you the information required to make timely and appropriate decisions to simplify the dry period.
Body Condition Score
It is an ideal time to identify any cows that are thin within the herd (BCS < 2.75) and put them on once-a-day milking for the remainder of lactation, which will help to recover approx. 0.25 BCS over 8 weeks.
Alternatively, allow a 12-week dry period for first lactation animals and thin, early-calving cows. Ad-lib 68 dry matter digestibility (DMD) silage will be adequate for dry cows to gain an additional 0.25 BCS over an 8-10 week dry period.
Consideration should also be given to heavier animals within the herd as these will need to be managed during the dry period to avoid getting over-conditioned (BCS > 3.5 at calving). High BCS cows (3.5+) and late-calving cows may be offered lower quality forages (64-66 DMD silage) for a period of time. However, they must return to a higher quality, low K silage (68-70 DMD) for the final month before calving to meet the energy requirements of the rapidly growing calf. Over-conditioned, older cows (4th lactation plus) are at increased risk of milk fever at calving, and lower dry matter intake (DMI) and metabolic issues post-calving.
Weighing
Weighing of heifers should be carried out, if not yet completed, to ensure under target animals can be grouped and appropriately supplemented over the housed period to ensure they are on target for breeding next May. These animals should be 40% of their mature body weight at 9 months (November 1st for a heifer born February 1st).
Join our workshop at the Teagasc National Dairy Conference for a more detailed discussion on managing transition cow nutrition to support a better calving season next spring.
Further details on the Teagasc National Dairy Conference are available here.