It’s not too early to start thinking about drying off your lighter cows

By Hamish Clare, Anexa FVC Morrinsville Veterinarian

Most of you will know the body condition score (BCS) targets at calving of 5.0 for mixed age (MA) cows and 5.5 for first and second calvers (R3yo). These are not just nice targets to achieve. They should be the aim of every farmer at this time of year and a number of studies have shown that reaching these targets will maximise milk production and reproduction potential.

Through following the BCS of cows over a number of farms in the last two seasons I’ve found that typically cows struggle to gain significant condition while they are still milking i.e. gains of only 0.1 BCS per month are common on low inout farms. If cows are fed very well and on once a day (OAD) milking they may gain 0.3 BCS per month. When cows are dry however farmers are often able to achieve gains of 0.5 BCS per month and in some cases gains of 0.5 BCS in 20 days when they are being well supplemented (for example with PKE and/or maize silage).
Time is limiting so often drying off lighter cows early is the best option. MA cows at BCS 3.5 or less and R3yos at BCS 4.0 or less need attention now.

Example dry off dates to reach BCS targets:
If the start of calving is around the 9th July (PSM 1st Oct), then the recommended dry-off dates are given in the table to the right.

Assumptions:
- Dry cows are being well fed above maintenance
- No BCS gain in the 1st 10 days after drying off
- Dry Cows are gaining 0.5 BCS in 30 days
- No BCS gain in the 30 days prior to calving
- The cow is calving at the PSC i.e. 9th July

If you know the calving dates for your cows, then your later calvers can be milked for longer. A rougher way can be to work back from the half-way point of your calving (around 14 days after the start of calving depending on your calving pattern) so the majority of cows are at target.

If you can feed your dry cows well (good quality supplements make this more achievable) and have gains of 0.5 BCS over 20 days rather than 30 days then a BCS 3.5 MA cow or BCS 4.0 R3yo could be milked for a month longer and still achieve calving BCS targets.

As with life nothing is perfect and the same applies to the BCS of your herd. So don’t get too caught up on solely the average of your herd. Focus also on the range of BCS in your herd and aim to have no more than 15% below and 15% above their BSC calving target (yes too many fat cows can be a problem).

Drying-off low producing, fat cows early can also be beneficial. These cows put fat on their back instead of milk in your vat. When feed is short, it makes sense to feed your more productive cows better. There is often an area of low quality feed on the farm where these cows can be put to maintain themselves, such as steep sidelings or gullies.
Don’t forget your young stock. This is often when groups begin to start falling behind. Don’t let the time between drenches stretch too long, especially after periods of rain and when stock are eating pasture down to low levels.

Anexa FVC has 14 Vets certified as BCS assessors. We offer a one-off visits to score approximately 70 cows per mob to get an average Or we can score every cow in the herd to give individual recommendations. We also have Vets who can help with feed budgeting. This provides valuable information, in particular for feed management. Contact your local vet if you are interested in discussing this further.


Date Added: Wednesday, 1st March 2017


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