Drying off decisions influence next season

Ensuring good management practices for drying off cows is a topic we hear about annually. It all starts with having good practices during late lactation. These set the herd up for its best chance to succeed in the following season, especially for good animal health and reproductive performance.

From past research, we know that trying to chase milk production now can have negative impacts on your herd’s subsequent milk production potential and reproductive performance, as this often comes at the expense of reaching body condition score (BCS) targets at calving.

So, what can you do now to set yourself up well for the next six months? Here are some areas to focus on as you plan for drying off so you can reap the rewards down the track.

Setting up for next season

We all want the best reproductive outcomes for our animals, year on year. Some people may think the decisions made at mating time have the biggest impact, but the most important decisions are, in fact, made now.

The key piece of this puzzle is to look at the BCS of every cow, not just the average of the herd, and decide the drying off date and management that best helps them to reach target BCS by calving.

It has been established that cows that calve at BCS 5.0 produce, on average, 12kg milksolids (MS) more across the lactation and are 6% more likely to cycle pre-mating than a cow that calves at BCS 4.0.

Reaching body condition targets at calving is key to good reproduction, and the outcomes that you will see when you start pregnancy testing in the next lactation. Additionally, it helps ensure a smooth transition period from late pregnancy and early lactation and reduces the risk of milk fever and metabolic disorders.

In late lactation, it is essential to have a plan that ensures your cows are dried off with enough time to reach their pre-calving BCS targets: 5.0 for mature cows, 5.5 for two and three-year-olds.

There are a range of ways to approach this, but some suggestions include:

• Body condition score your cows now, or make use of an independent BCS assessor, to provide a good baseline.
• Do a feed budget now to work out how much feed you have onhand to put condition on cows during the dry period.
• Draft out lighter cows into a separate mob to preferentially feed.
• Consider reducing milking frequency for the light mob, or the entire herd.
• Dry off cows in mobs, based on their individual BCS, so that lighter cows have time to gain condition.

When working out the feed required, remember that; 1) cows struggle to gain condition whilst still milking, and 2) they don’t gain condition for up to 40 days of their dry period – that’s the first 10 days after drying off and last 30 days before calving. Make sure you are accounting for this when planning drying off dates.

A good rule of thumb is that cows can put on 0.5 of a BCS unit per month, when fed pasture alone. Also, the approximate amount of feed required for a 1.0 unit increase in BCS is between 115kg DM and 225kg DM, depending on the feed used and breed of cow.

It’s important to keep an eye on the BCS of cows with the least condition, and those with the most. There should be no more than 15% of the cows below target and 15% above target. An individual BCS plan for each individual cow will also help better support her health and preparation for calving.

Overall, focusing on every cow achieving target BCS at calving will help improve reproductive performance later in the year, and have a good influence on the health of your herd.

Getting through drying off

Farmers that navigate the drying off period successfully have identified some non-negotiables to minimise mastitis in the first few days and weeks after drying off, while also minimising mastitis in the next lactation.

Top tips include

1. Discuss and organise the most appropriate dry cow products for your herd with your vet well in advance.
2. Hygiene is key – book a training session with your vet or vet technicians for a reminder of good hygienic techniques – every member of the team benefits from timely reminders of what’s required.
3. Dry off in manageable mobs for the available labour – budgeting on no more than 20 cows per person per hour.
4. Check the weather forecast – avoid drying off when it is raining.
5. Mark up cows that receive different treatments.
6. Use gloves and clean each teat immediately before administering a treatment.
7. Keep treated cows well away from any cows that are still being milked.
8. Check treated cows daily in the paddock after drying off and run once per 14 days through the farm dairy to check for problems.

All these things may not be achievable on every farm, but there will be some alternatives. Spreading the task over several days or bringing in your relief milker can help you get through drying off smoothly.

Being such an important topic, DairyNZ has been running some great events across the country on drying off and reproductive performance in the past few months. The DairyNZ team, supported by local veterinarians, have been able to have some good conversations with farmers about their plans, and how to support them.

These events have highlighted a lot of the information here, including the importance of BCS at drying off, the key drivers of reproductive performance, and the importance of early intervention.

The important theme continues to be plan now for your approach to drying off and set the herd up well for next season.

DairyNZ has a range of information available to support you at dairynz.co.nz/bcs and dairynz.co.nz/mastitis. Alternatively, you can reach out to your DairyNZ regional team for further support.