Many dairy areas have finally received enough rain so that runoff is filling dams and sub soils are wetting up.
However, farmers now need to actively try to avoid or at least minimise pugging damage in waterlogged paddocks.
Hopefully many have learnt from the very wet winters of 2011 and 2012 and have some robust strategies in place to nurse their pastures through the rest of winter if it stays wet.
With soils very wet and even waterlogged in some vulnerable soil types, even light showers of 15–20 mm can result in pugging damage.
Very wet soils lose their structural integrity or strength and become more easily damaged by cattle hooves and vehicles, hence the pugging.
Experiences in recent wet winters have been backed up Victorian and New Zealand research that has measured pugging damage of reduced pasture utilisation by 40-60% and set back re-growth over the following spring and early summer months by 20-80%.
The severity of damage will depend on soil type, degree of waterlogging and most importantly, grazing management.
The greater the severity and extent of pugging damage, the greater the set back and cost of pasture restoration.
Set the rotation so cows are going into ryegrass pastures with at least 2.5-3 leaves, adding extra supplement to leave a residual of about five centimetres, maybe a bit higher if soils are likely to be pugged.
If the weather does stay wet and paddocks are severely damaged this round, these paddocks may have to be grazed once or twice again before they start to dry out and their pasture production will be greatly reduced and pugging damage increased.
Whatever you do, try to avoid pugging damage at all costs.
There are two major approaches in terms of grazing management that can be used to avoid or reduce pugging damage:
- Leave animals on the paddocks but use different grazing techniques.
- Practise “on-off grazing”.
There are some possible grazing techniques to minimise pugging damage while leaving animals on the paddocks for their daily feed.
With the following suggestions, it is crucial that the paddocks have good cover, at least 10cm and preferably over 15cm height, to allow cows to eat big mouthfuls with little need to walk too far.
If pastures are shorter than say, 10cm, count on ploughed paddock.
Any shortfall in intakes may need topping up with a high quality supplement back at the shed or along the laneway.
Avoid taking tractors and trailers down laneways and definitely not into paddocks.
If hay or silage must be fed in the paddock, try to do so before the cows go down to the paddock to avoid unnecessary walking to and following the tractor.
Many farmers have tried the following techniques in past very wet winters with reasonable success.
If you get the chance, discuss the various options with farmers who have tried these or have other ideas not discussed here.
Talk is cheap, pugging is not!.
- Offer 2/3 day feed and 1/3 night feeds. Offering only about two thirds of the 24 hour’s allocation for the day feed, and the remaining one third at night will allow the cows to have access to clean un-fouled pasture for the night feed. If there is enough pasture to satisfy their intake, they won’t need to walk far.
- Offer the entire 24-hour break at once. This technique allows the cows to spread out over the paddock for the entire 24-hour feed with some cows heading to the back while the rest hang around the front half of the paddock. At the night feed, more of the herd make their way to the rear of the paddock but not all, so pugging damage is minimised overall, and especially towards the rear of the paddock.
- Ensure cows have a good feed before entering the paddock. Some farmers offer extra feed (good quality fodder) in addition to the bail feed at the dairy before sending them to the paddock. Once in the paddock the cows tend to lay down after a quick nibble and may top up on pasture later in the morning but with much less walking resulting in less pugging damage. Monitor residuals carefully. A concern with this technique is that residuals may be left too high (6–10cm) which will need addressing later.
- Enlarging the area to be grazed. Enlarging the area to be grazed has the effect of speeding up the rotation but does reduce the density of hooves in a given area and so reduces the pugging damage. But does it? In very wet windy weather, often the larger area may become damaged since there is more area available to be walked over. The damage may not be evident until closer inspection. If this strategy is used, try not to shorten the rotation for too long as the amount of pasture available for the next round will be substantially lower.
- Use higher ground, free draining paddocks first.Some farmers are fortunate to have some soils which are less prone to pugging such as alluvial river flats or red soils so can be grazed in wet conditions thereby taking pressure off the paddocks more prone to pugging.
- Graze vulnerable paddocks before they become too waterlogged.Try to second guess upcoming very wet weather by using the weather websites, watching the forecast and your own experience (gut feel) and graze the vulnerable paddocks before the wet weather arrives. This may mean grazing at, say two leaves, but better than pugging a paddock.
