Wet Weather Management
7 min read
Prolonged wet weather poses challenges to normal farming activities by saturating soils. This page provides information on managing the impact of wet weather on dairy farming. It covers key areas such as stress management, minimising damage to soil and pasture, protecting animal health, managing pasture cover and feed intake, and ensuring effluent and compliance risk management. Strategies include on/off grazing, strategic paddock selection, and magnesium supplementation for stressed cows. There's also guidance on how to look after yourself and others, with various support and contact details provided for adverse weather support and further assistance.
Prolonged wet weather can saturate soils, affecting the ability of farmers to farm as they would normally. This page contains information and advice on dealing with wet weather.
Looking after yourself and other people
Make sure people are your number one priority. Look after yourself and your team, check in on your contract or sharemilkers, and 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 are in this camp, contact your GP or health professional or the Rural Support Trust as soon as possible for advice.
Minimising soil and pasture damage
The key to getting through a wet spell, especially during early lactation, is to avoid pasture damage at all cost.
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 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 - custom-built stand-off pad, races (confine cows to limit damage), paddocks that have been identified for regrassing, yards, 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
Minimise disturbances to stock
Where possible, stay away from stock in wet conditions as disturbed stock tend to pace.
Selecting paddocks for standing cows off
If you don’t have stand-off facilities and need to use a sacrifice paddock, consider the following factors for selecting low-risk paddocks during this wet weather:
Protecting animal health
Mastitis and lameness pose the most immediate health risks to livestock during prolonged periods of wet conditions.
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.
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.
Other methods of providing magnesium are:
Managing pasture cover and feed intake
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 plugging.
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.
As calving progresses, prioritise animals based on which require the best feeding:
Reducing milking frequency to ease workload and limit BCS loss
If you and your team are struggling to get everything done, consider milking OAD for the first 3 weeks and review or flexible milking for 3-6 weeks, or all season. Many farmers already implement OAD during calving to help ease the workload.
Although you might forgo some production by going OAD or flexible milking, also consider the benefits. With already low average pasture covers, unless you can buy in plenty of supplement feed, milking twice a day is likely to result in further body condition loss and increase the risk of metabolic issues.
In 2022, farms with very low pasture cover (<2000 kg DM/ha) for all of spring reported they were still able to achieve good mating results by milking OAD and feeding as well as possible. When pasture cover is very low, feed supply will be the major limitation to milk production, not milking frequency.
Managing effluent and compliance risk
If the recent weather event has resulted in your pond levels getting to a full space and you are at risk of non-compliance it is recommended that you:
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.
You can increase your resilience for future wet spells by carefully planning for the various possibilities. The planning process involves how to feed cows and how you will manage the financial implications. Visit the business planning page for more information.
Rain, rain, rain. How are other dairy farmers managing their way through this exceptionally wet winter? Hear from Hauraki Plains farm owner John Garrett, Cambridge farm owner Marc Gascoigne, and Northland herd owning sharemilker Carl MacDonald, who explain how they're trying to minimise soil damage while still adequately feeding the cows. They discuss round lengths, cow comfort, team morale, mental health, lessons from previous wet winters, and more.