Wet weather management

If you and your team are struggling to get everything done, consider milking OAD for the first 3 weeks of calving and review, or flexible milking for 3-6 weeks, or all season. Many farmers already implement OAD during calving to help ease the workload.

Look for opportunities to reduce workload where you can. Consider bringing in relief staff or additional help, simplifying non-essential jobs, and making sure everyone gets an opportunity for a break.

Make sure people are your number one priority. Look after yourself and your team, check in on your contract or sharemilkers, your farming family, friends, and neighbours.

Looking after the animals and getting the farm back on track requires you to be doing well first. If you are feeling stressed make sure you reach out and talk to someone. There is plenty of support available – check out where to get help.

Sometimes a stressful situation such as this can be the last straw for someone already under pressure. If you think you, a staff member, or farming colleague need some help, contact your GP, health professional, or the Rural Support Trust as soon as possible.

The key to getting through a wet spell, especially during early lactation, is to avoid pasture damage where practicable.

On/off grazing is the most effective grazing strategy for wet weather

Pugging paddocks now will reduce feed in the next round and the rest of the season. Pasture production in pugged paddocks is reduced by 25-30% because of reduced clover and N fixation, reduced earthworm population and reduced drainage.

Cows can consume their daily intake in 6-8 hours, so they can be stood off paddock if necessary to avoid damage. Alternatively, stand cows off paddocks during the day and let them graze at night.

Cows need to lie for at least 8 hours a day. If lying is restricted, they will lie in preference to grazing when put onto pasture, resulting in underfeeding.

Places to stand cows off include - a custom-built stand-off pad, races (confine cows to limit damage), paddocks that have been identified for regrassing, yards, or a waste area. Ensure they have enough space to lie down - at least 3.5m² per cow if on woodchip, sand or concrete for up to two days; at least 5m² on woodchip or sand for more than two days; and 8m² if on crops or feed-out paddock.

E.g: a 400-cow yard would only accommodate 200 cows as a standoff area.

Make sure the stand-off surface, particularly concrete, is kept free of stones, as the cows feet will be extremely soft and susceptible to damage. A footbath with zinc or copper sulphate or formalin could be used to harden the feet, but start this early and keep it clean.

Graze paddocks strategically

• Make breaks as square as possible to help reduce pasture and pugging damage. Back fence to prevent stock from back-grazing and causing further damage.
• Walk the cows over long pasture. Long grass gives protection when stock or vehicles are driven over it.
• Graze the back of paddocks first or set up temporary laneways to prevent cows from walking back over a grazed section of paddock.
• Move the cows in and out of different gateways to reduce the damage caused. You can also drop the wires between paddocks to avoid walking over grazed areas.

If you don’t have stand-off facilities and need to use a planned re-grass paddock, consider the following factors for selecting low-risk paddocks during this wet weather:

• Ideally, select a paddock with no waterway. If there is a waterway, have a minimum of a 5m buffer around the waterway.
• Fence off critical source areas such as gullies and swales (low-lying parts of a paddock that collect rainfall runoff) to keep stock out.
• Select paddocks with the lowest slope possible.
• If break-feeding, graze towards the waterway or swale, maintaining as much buffer as possible.
• Don't calve on these paddocks.
• Ensure stock have water.

Mastitis and lameness

Mastitis and lameness pose the most immediate health risks to livestock during prolonged periods of wet conditions.

• Make sure all lameness prevention measures are in place e.g. gentle handling, alternative milking intervals.
• Consider alternative milking intervals (e.g. OAD, 3 times in 2 days) to take the pressure off light and lame cows.
• If standing cows on the yard, make sure it is free of stones.
• Expect a slight increase in lameness if cows are being yarded for long periods of time. Close monitoring (lameness scoring) of the herd is crucial to identify and treat cases quickly.
• Mastitis prevention: focus on teat condition, and keep the emollient level up in the teat spray.
• Where teats are heavily contaminated, pay extra attention to teat hygiene and check that teat spray coverage remains effective.
• Regular stripping to identify mastitis early - environmental mastitis increases with wet weather, regular stripping (a quarter per milking) can help identify cases early.
• If practical, run the dry cows through the shed every 3 days for teat spraying.
• Talk to your vet about any animal health concerns.
• Magnesium is critical. Be aware cows will not be drinking as much if adding Mg to the water supply and utilisation of Mg dusted onto pasture may be reduced.
• For more information visit managing mastitis or the lameness section of the website.

Other illnesses/disease risk(s)

Be alert for other animal health issues. If you see an increase in diarrhoea, sick cows, or unusual disease patterns, identify affected animals early and contact your vet for advice.

If the wet weather occurs over calving, keep calf sheds clean and dry, maintain good hygiene and biosecurity, and replace wet or heavily soiled bedding as needed.

Metabolics

Work with your vet to do bloods for metabolics and adjust your supplementation regime accordingly - checking springers, colostrum and milking cows can ensure you manage each mob appropriately. Ensure you have extra product on hand to manage a potential increase in metabolic down cows. Preventing down cows is good for the cow and for people – one down cow can take the same time to care for as milking a herd of cows.

Magnesium is a critical mineral especially when cows are stressed and at calving. It is difficult in the wet to achieve the target magnesium intake using dusting. Consider other methods of providing magnesium to both eliminate the job of dusting and ensure the cows are getting enough magnesium. Other methods of providing Mg are: Dust colostrum breaks with at least 300 g/cow lime flour in the wet. If still having issues with metabolics, consider using a starter drench as they calve. Some products will give 7-10 days protection from one dose at calving.

Keep an eye on actual cow intake, not just the feed offered. Wet conditions can reduce grazing time and pasture utilisation, meaning cows may eat less than expected, even when pasture appears to be available. Use a combination of post-grazing residuals, milk production, cow behaviour, and body condition to assess whether cows are getting enough feed.

Tools to utilise: Spring Rotation Planner Tool and DairyNZ feed budgets

Pasture walk or drive to establish the feed situation. If average pasture cover is less than required prior to calving (typically 2200-2400kg DM/ha), the priority is preserving pasture cover, and not using pasture to increase BCS. Aim to get pasture cover to at least 2100 kg DM/ha and no lower than 2000 kg DM/ha.

This is because when pasture cover is low, growth rates are reduced as fewer leaves are capturing light.

If pasture cover is very low, aim to keep it above 2100 kg DM/ha and no lower than 2000 kg DM/ha.

This will require holding cows to a set area and moving them off to prevent widespread pugging.

It is easier to hold dry cows on a tight pasture rotation length than lactating cows so slow the rotation as quickly as possible. Speeding up the round (offering cows a larger area) can result in less pasture being available next round. If you increase the area offered, be prepared to feed more supplements next round.

• Use supplement strategically to help maintain the desired round length and protect pasture cover where there is a genuine feed deficit.
• As pasture growth and availability recover, reassess the feed budget before reducing supplement. Avoid removing supplement too quickly while pasture cover is still rebuilding.
• Update feed budget and monitor amount of supplement on hand.
• Feed out before cows go onto the break or into the paddock (less walking around the break).
• Take care when changing cows’ diets, and slowly introduce them to differing feed types and quantities. Take special care with grain and avoid feeding too much too quickly. Increase at no more than 1kg per day and only after the cows have been eating 1kg grain for at least 5 days.
• Act early where cows are being underfed. The severity and duration of feed restriction both matter, particularly through early lactation and as cows approach mating. Prolonged restriction can affect body condition and reproductive performance.

As calving progresses, prioritise animals based on which require the best feeding:

1. Colostrums (Additional information below: Understand the transition cow)
2. Milkers
3. Springers
4. Dries – maintenance only

• Nitrogen is a growth multiplier, not an emergency feed source. Before applying nitrogen during prolonged wet conditions, consider whether pasture is actively growing and whether the extra pasture grown can be grazed effectively.
• Cold, wet or waterlogged conditions can reduce and delay the response to nitrogen. Consider soil temperature, drainage, current pasture growth and whether other nutrients or soil conditions may be limiting growth.
• Focus on the pasture that can be eaten, not just the pasture that may be grown. If paddocks will remain too wet to graze without causing damage, the value of the nitrogen response may be reduced.
• Where the expected response is low, or utilisation is likely to be poor, compare the cost and reliability of nitrogen-grown pasture with available supplementary feed options.

• If you and your team are struggling to get everything done, consider whether OAD or flexible milking could help ease the workload during challenging conditions.
• During prolonged wet weather, OAD or flexible milking may also create valuable time for other priority jobs such as grazing and feed management, caring for springers, colostrum cows and calves, managing animal health, and reducing pressure on the farm team. Balance these benefits against the potential impact on milk production.
• OAD should not be viewed as a substitute for addressing a feed deficit. Where feed is limiting, continue to focus on maintaining cow intake and consider the feed options available.

For more information head to Early lactation once-a-day (OAD) milking or Flexible milking.

• Prolonged wet conditions can put pressure on effluent storage and reduce opportunities for safe application. Keep monitoring available storage and avoid allowing the situation to become critical.
• If pond levels are becoming a concern or there is a risk of non-compliance, contact your regional council early to discuss the situation and available options.
• Only apply effluent when soil, weather and farm conditions allow it to be done safely and within your regional requirements. Consider soil and landscape risk and avoid any direct discharge to surface water. DairyNZ guidance emphasises matching effluent management to soil and landscape risk.
• Good effluent management and adequate storage provide greater flexibility during prolonged wet periods.

Best practice management year-round, adequate storage, and keeping a good working volume available for situations like the recent weather will ideally enable you to get through these weather events without concern of non-compliance.