Winter can be a critical time for soil erosion, stream pollution and animal welfare on livestock farms. Some wintering systems, especially brassica and fodder beet crops, pose particular risks to water quality with exposed soils becoming saturated, pugged and carried away during heavy or prolonged rain into waterways. As well as carrying soil particles, this runoff contains high levels of phosphorus, nitrogen and bacteria that are a risk to downstream water quality.
Intensive winter grazing (IWG) has become publicly controversial in recent years. Much of the focus has been on poor practice on dairy farms, but some unfortunate incidents on deer farms have also been brought to public attention on social media and in television newscasts.
In 2020, the government proposed to introduce a National Environmental Standard (NES) to control intensive winter grazing (IWG) practices in 2021. In March 2021, the standard was deferred until May 2022 to give farmers time to modify their wintering practices and to demonstrate that the proposed NES need not be as prescriptive as first proposed.
It is therefore crucial for deer farmers to adopt best winter grazing practices at all times, but particularly in the winter and early spring of 2021. Regional Councils will be stepping up their monitoring and activists will be looking for examples of bad wintering practice as part of their campaigns for stricter regulation.
To encourage farmers to adopt best practice for the current season (2021) farming groups – including Deer Industry New Zealand – have developed a checklist of good practices.
From 2022 onwards farms will require an IWG module (management plan): the Ministry of Primary Industries and the Ministry for the Environment have developed a module that explains what farmers need to do to meet the expectations of government, the wider public and their fellow farmers.
Good wintering systems and practices minimise soil disturbance and erosion. Whatever wintering system is used, environmental effects need to be closely monitored and appropriate mitigation measures undertaken. The environmental impact of a wintering system will depend on-
- its day-to-day management;
- the extent of its soil disturbance;
- the weather;
- its location; and
- particularly its connectivity to ephemeral flows and streams during rain storm events.
It is important to carefully plan winter crops and feed-out areas by utilizing the most appropriate paddocks on your farm as indicated in your farm’s LEP Land Use Capability (LUC) classes map and the risk analysis process via your LEP (see Section 9 of Landcare Manual).
A growing number of deer farmers are investing in indoor wintering systems.
A big driver has been the need to reduce the run-off, nutrient loss and soil damage that can be associated with intensive winter feeding. In addition, there can be significant animal welfare and management benefits.
Indoor wintering is a highly effective way to reduce the impact of winter feeding on water quality and soil health.
Deer adapt well to being wintered indoors. There are no animal health issues, but bullying by dominant hinds needs careful management.
Indoor wintering is a major investment, especially if there are no existing buildings that can be repurposed as wintering barns. New or upgraded farm machinery may also be needed.
Whether this investment stacks up economically and environmentally will depend on the circumstances of an individual farm.
The pros and cons
Good for the environment
- Greatly reduced run-off of sediment and bacteria. Less run-off and leaching of nutrients. Healthier streams and ground water
- Less soil damage from pugging and the use of heavy equipment
- Less reliance on energy- and GHG-intensive winter crops
- No resource consent fees when feeding indoors
- If you are already feeding baleage or other conserved feed in winter, less of it will be needed
- Pastures remain productive for longer, reducing the need for replacement
Good for management
- Deer become calmer and easier to manage as a result of close contact with humans
- No escapes! You know where your deer will be when you check them in the morning
- Flexible – deer can be held indoors for as long as is needed, depending on the season
- Easier to segregate stock into mobs based on age, sex, breeding etc than it is on crops
- Regulatory consents are not required in many regions
- Easy to work out how much feed is needed and to tailor diets to the needs of different stock classes
- Easier to feed a variety of supplements
- With baleage and other conserved feeds there is earlier certainty of winter feed supply. No waiting to find out how a crop has yielded
Good for animal health and welfare
- Individual deer can easily be separated out for the treatment of disease and injury
- Warm, dry places to lie down and rest, no weather-related stress
- No mud and therefore less scope for bad photos and complaints from members of the public
- Assured diet
Good for production
- Less pasture damage during winter, maximising spring growth
- No paddocks removed from grazing while crops are growing and no soil disturbance from renovating paddock after grazing
- Lower feed demand, better feed utilisation
- Used bedding material is spread onto paddocks after winter, adding nutrients and organic matter back into the soil
Good for the team
- Less working in mud and winter storms
- No more wasted time rounding-up stock that disrespect electric fences
- No more shifting breaks
Good for velvet stags
- May extend the productive life of stags
- High protein supplements can be fed from early spring, with minimal wastage, to boost velvet production
Costly to set-up
- Building a barn and related facilities is expensive
- Possible need to replace/upgrade feeding out and muck spreading machinery
Expensive to operate
- Bedding needs to be bought and spread, then removed and spread on paddocks
- Conserved feed is usually more costly than high-yielding crops like fodder beet which – because they are wet feeds – are unsuitable for feeding in a barn
- High quality feed is essential. If your silage/baleage is low in ME or protein, you may need to buy in costly supplements
- Most sheds are used for only 3-4 months/year
- Bedding can be costly in some regions
- No real labour saving. Deer need checking twice-daily and feeding every day or two
Animal welfare downsides
- A few animals can be victims of bullying. Look out for ‘plucking’ (hair loss), especially among low-rank hinds and sometimes weaners
- Stags can become agitated and aggressive if there is insufficient space for them
- Bedding can become wet and soiled if using wet feed, or a water trough is damaged
- More non-recyclable baleage wrap may be need to be disposed of
- Used bedding must be stored in a location where nutrients won’t leach, before being spread on a paddock
What are the costs?
Wintering Barns and Forage Crops (June 2022) by AgResearch scientist David Stevens summarises the capital and operating costs of indoor wintering, based on the costs incurred by five Southland deer farmers.
The capital costs of two types of shed – a conventional fully-enclosed clearspan barn and a polytunnel – are analysed.
The study provides a good template for carrying out costings of your own. Bear in mind that building and construction costs have increased dramatically since the sheds in the study were built.
Read the Deer Fact
A Deer Fact sheet ‘Wintering deer indoors’ has been published by DINZ as part of the P2P programme. It covers:
- Things to weigh-up before investing in a wintering barn
- Meeting the needs of your deer
- Design principles
- How to manage an indoor wintering system
- Farmer experiences
Riparian protection and filter strips are an essential practice. In some cases, however, there is a risk that even they may not cope with the volume of sediment, nutrients and bacteria during heavy storms and especially so for dissolved reactive phosphate and E. coli.
Anywhere that storm water can flow through needs to be considered as a risk area. Muddy gateways and troughs, winter crops in valley floors, poorly located silage pits and winter self-feed structures can become 'Critical Source Areas' for contaminants especially in winter time. refer to pg 30 of Landcare Manual.
Feeding deer on feed pads with good surrounding shelter offers some protection to both the feed (reducing wastage) and the rested farm paddocks. However runoff from feed pads still needs to be directed safely to capture contaminants before they reach the water ways. Wintering hinds in woodlots in conjunction with self-feed silage pits effectively removes them from the pasture, providing pasture relief and protection plus the ability to save pasture for weaner growth and production over winter and into early spring. However, if the woodlot is on steeply sloping land with active winter waterways, soil and nutrient loss from this area can still be a problem and the net gain for the farm’s environmental footprint is questionable in this situation.
Sediment ponds or detainment bunds can be placed downstream of wintering areas to contain peak storm flows coming throug the wintering system. Their effectiveness is limited to capturing sediment and some particulate phosphorus. Residency time in still water in the pond is important as soil particles need to have time to settle out. To achieve a worthwhile residency time, sediment ponds need to have a storage to catchment ratio of not less than 100:1, i.e. 100 cubic metres of temporary pond storage for each hectare of contributing catchment.
Some regional Councils now have rules prohibiting stock access to waterways during the winter months from 1 May to 30 September. Get advice from your regional council for your area. For further information on best practice, click here >>
To download the module and related documents, click on the links below:
To download our handy Deer Fact sheets on winter grazing management and good environmental practice, click on the links below:
- Intensive winter feeding: minimising the environmental risk >>
- Planning for winter: best options for deer and their environment >>
- Protecting waterways from wallow and feed pad run-off >>
- Effective nutrient management on deer farms >>
- Farm Environment Plans: the whys and hows of preparing them >>
- Fence-pacing: costs and solutions >>
- Indoor wintering >>